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18 Commits
Author SHA1 Message Date
Rui Ueyama 6695c49379 Bump mold version to 0.9.2 2021-07-12 13:51:34 +09:00
Artur Sinila dd116fb3a7 Fix test/run.sh for cases when /usr/bin/ld -> /usr/bin/mold
Signed-off-by: Artur Sinila <[email protected]>
2021-07-12 13:50:53 +09:00
Rui Ueyama 6c2df40850 Align section header to a E::wordsize boundary
Fixes https://github.com/rui314/mold/issues/80
2021-07-08 17:45:36 +09:00
Rui Ueyama 09f01b4377 Fix regexp 2021-07-08 17:45:28 +09:00
Nehal J Wani 683bae0ec5 Do not replace IFUNC with FUNC in .dynsym
This is a partial revert of dd04357

Signed-off-by: Nehal J Wani <[email protected]>
2021-07-08 17:45:12 +09:00
Nehal J Wani 19fd8fc80c Ensure correct visibility of symbols in .dynsym section
Signed-off-by: Nehal J Wani <[email protected]>
2021-07-08 17:45:04 +09:00
Rui Ueyama 165f74e43c Fix assertion failures
mold failed with `make EXTRA_CPPFLAGS="-Wp,-D_GLIBCXX_ASSERTIONS" test`,
which enables extra assertions.

Thanks for @nehaljwani to find out the flag.
2021-07-08 17:44:34 +09:00
Nehal J Wani 8de8ab49ca Fix out of bound check in get_shndx()
Assert failure:
/usr/include/c++/11.1.0/span:276:
  std::span::reference
  std::span<ElfSym<X86_64>, 18446744073709551615>
     ::operator[](std::span::size_type)
         const [_Type = ElfSym<X86_64>, _Extent = 18446744073709551615]:
           Assertion '__idx < size()' failed.

GDB stacktrace:
Thread 2.4 "mold" received signal SIGABRT, Aborted.
[Switching to Thread 0x7fabc3d3f640 (LWP 17804)]
0x00007fabc496fd22 in raise () from /usr/lib/libc.so.6
(gdb) bt
 #0  0x00007fabc496fd22 in raise () from /usr/lib/libc.so.6
 #1  0x00007fabc4959862 in abort () from /usr/lib/libc.so.6
 #2  0x000055a9685eb018 in std::__replacement_assert (...)
     at /usr/include/c++/11.1.0/x86_64-pc-linux-gnu/bits/c++config.h:504
 #3  0x000055a968614c47 in std::span<ElfSym<X86_64>, ...>::operator[] (...)
     at /usr/include/c++/11.1.0/span:276
 #4  ObjectFile<X86_64>::get_shndx (this=<...>, esym=...) at ./mold.h:2145
 #5  ObjectFile<X86_64>::get_section (this=<...>, esym=...) at ./mold.h:2154

Signed-off-by: Nehal J Wani <[email protected]>
2021-07-08 17:44:24 +09:00
Nehal J Wani 14078d38ab [tests] Improve test for -spare-dynamic-tags
The default size and offsets of the .dynamic section are not necessarily
same with different builds of clang. For example, some builds can make
clang pass --hash-style=gnu to the linker and some --hash-style=both.

This change updates the test to compute the difference in size of the
.dynamic section before and after using the flag -spare-dynamic-tags,
making it independent of the compiler build.

Signed-off-by: Nehal J Wani <[email protected]>
2021-07-08 17:43:57 +09:00
Rui Ueyama 87204bf7bf Create $PREFIX/bin if not exists 2021-07-08 17:43:19 +09:00
Rui Ueyama e526945f5d Fix tests for non-Ubuntu-20 systems
Fixes https://github.com/rui314/mold/issues/67
2021-07-04 00:29:27 +09:00
Nehal J Wani 6a5626e3a7 [tests] Fix pie test when cc isn't built with --enable-default-pie
mold: /__w/mold/mold/test/tmp/pie/a.o:(.text): R_X86_64_32 relocation
       against symbol `.rodata' can not be used; recompile with -fPIE
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Signed-off-by: Nehal J Wani <[email protected]>
2021-07-04 00:28:57 +09:00
Rui Ueyama e2c0d36c3e Support R_386_TLS_IE relocation 2021-07-04 00:28:29 +09:00
Rui Ueyama 16c23858fd Split a function and add tests 2021-07-04 00:28:05 +09:00
Mitsuo Heijo 4565d27c14 Fix DSO detection for installed with PREFIX
Signed-off-by: Mitsuo Heijo <[email protected]>
2021-07-04 00:27:54 +09:00
Artur Sinila c611fb05c0 Makefile: add $(DESTDIR) to strip 2021-07-02 17:03:59 +09:00
Rui Ueyama 1191627942 Do not set a variable instead of undefine it later 2021-07-02 17:03:41 +09:00
Artur Sinila 776f9ee6e0 Various fixes in Makefile
Signed-off-by: Artur Sinila <[email protected]>
2021-07-02 17:03:29 +09:00
3185 changed files with 44675 additions and 745785 deletions

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-13
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# These are supported funding model platforms
github: [rui314] # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
patreon: # Replace with a single Patreon username
open_collective: # Replace with a single Open Collective username
ko_fi: # Replace with a single Ko-fi username
tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
liberapay: # Replace with a single Liberapay username
issuehunt: # Replace with a single IssueHunt username
otechie: # Replace with a single Otechie username
lfx_crowdfunding: # Replace with a single LFX Crowdfunding project-name e.g., cloud-foundry
custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']
-93
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@@ -1,93 +0,0 @@
name: Build all tarballs
on:
schedule:
- cron: '0 0 * * *'
workflow_dispatch:
jobs:
check-changes:
runs-on: ubuntu-24.04
outputs:
has_changes: ${{ github.event_name == 'workflow_dispatch' || steps.check.outputs.has_changes }}
steps:
- name: Check for new commits since last successful run
id: check
env:
GH_TOKEN: ${{ github.token }}
run: |
last=$(gh run list -R ${{ github.repository }} -w build-all.yml -b main -s success -L1 --json createdAt -q '.[0].createdAt')
if [ -z "$last" ] || [ "$last" = "null" ] || [ "$(gh api repos/${{ github.repository }}/commits?sha=main\&since=$last\&per_page=1 | jq length)" -gt 0 ]; then
echo "has_changes=true" >> "$GITHUB_OUTPUT"
fi
build-linux:
needs: check-changes
if: needs.check-changes.outputs.has_changes == 'true'
strategy:
matrix:
include:
- { target: x86_64, os: ubuntu-24.04 }
- { target: aarch64, os: ubuntu-24.04-arm }
- { target: arm, os: ubuntu-24.04-arm }
- { target: riscv64, os: ubuntu-24.04 }
- { target: ppc64le, os: ubuntu-24.04 }
- { target: s390x, os: ubuntu-24.04 }
- { target: loongarch64, os: ubuntu-24.04 }
runs-on: ${{ matrix.os }}
permissions:
contents: read
packages: write
steps:
- name: Checkout Repository
uses: actions/checkout@v6
- name: Install Podman
run: sudo apt-get update && sudo apt-get install -y podman qemu-user-static
- name: Login to GitHub Container Registry
uses: redhat-actions/podman-login@v1
with:
registry: ghcr.io
username: ${{ github.repository_owner }}
password: ${{ secrets.GITHUB_TOKEN }}
- name: Build a tarball
run: ./dist.sh ${{ matrix.target }}
- name: Upload artifact
uses: actions/upload-artifact@v7
with:
name: ${{ matrix.target }}
path: dist/mold-*.tar.gz
compression-level: 0
build-windows:
needs: check-changes
if: needs.check-changes.outputs.has_changes == 'true'
runs-on: windows-latest
steps:
- name: Checkout Repository
uses: actions/checkout@v6
- name: Build and Archive
shell: pwsh
run: |
mkdir build
cd build
cmake -T clangcl ..
cmake --build . --config Release -j $Env:NUMBER_OF_PROCESSORS
cmake --install . --config Release --prefix ../mold-install
cd ..
New-Item -ItemType Directory -Force dist | Out-Null
$version = $Env:TAG -replace '^v', ''
Compress-Archive -Path mold-install\* -DestinationPath dist\mold-$version-windows-x86_64.zip
- name: Upload artifact
uses: actions/upload-artifact@v7
with:
name: win-x86_64
path: dist/mold-*.*
-44
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@@ -1,44 +0,0 @@
name: Build native tarballs
on:
push:
workflow_dispatch:
jobs:
build-tarballs:
strategy:
matrix:
include:
- { target: x86_64, os: ubuntu-24.04 }
- { target: aarch64, os: ubuntu-24.04-arm }
- { target: arm, os: ubuntu-24.04-arm }
runs-on: ${{ matrix.os }}
permissions:
contents: read
packages: write
steps:
- name: Checkout Repository
uses: actions/checkout@v6
- name: Install Podman
run: sudo apt-get update && sudo apt-get install -y podman qemu-user-static
- name: Login to GitHub Container Registry
uses: redhat-actions/podman-login@v1
with:
registry: ghcr.io
username: ${{ github.repository_owner }}
password: ${{ secrets.GITHUB_TOKEN }}
- name: Build a tarball
run: ./dist.sh ${{ matrix.target }}
- name: Upload artifact
uses: actions/upload-artifact@v7
with:
name: ${{ matrix.target }}
path: dist/mold-*.tar.gz
compression-level: 0
+11 -166
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@@ -1,172 +1,17 @@
name: CI
on:
push:
branches: [ main ]
pull_request:
env:
UBSAN_OPTIONS: print_stacktrace=1:halt_on_error=1
branches: [ main ]
jobs:
build-asan-tsan:
strategy:
matrix:
target:
- ''
- '-DMOLD_USE_ASAN=On'
- '-DMOLD_USE_TSAN=On'
runs-on: ubuntu-24.04
timeout-minutes: 60
build:
runs-on: ubuntu-20.04
steps:
- uses: actions/checkout@v6
- uses: rui314/setup-mold@staging
- run: sudo ./install-build-deps.sh
- name: build
run: |
sudo apt-get install -y clang-18 clang gcc-multilib gdb dwarfdump zstd
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Debug -DCMAKE_C_COMPILER=clang-18 -DCMAKE_CXX_COMPILER=clang++-18 ${{ matrix.target }} ..
cmake --build . -j$(nproc)
- run: cd build; ctest --output-on-failure -j$(nproc)
- name: archive test results
uses: actions/upload-artifact@v7
if: failure()
with:
name: test-results-clang
path: |
build
!build/CMakeFiles
build-msan:
runs-on: ubuntu-24.04
timeout-minutes: 60
steps:
- uses: actions/checkout@v6
- uses: redhat-actions/podman-login@v1
with:
registry: ghcr.io
username: ${{ github.repository_owner }}
password: ${{ secrets.GITHUB_TOKEN }}
- run: .github/workflows/run-msan.sh
build-multi-archs:
runs-on: ubuntu-24.04
timeout-minutes: 60
steps:
- uses: actions/checkout@v6
- name: install-build-deps
run: |
sudo ./install-build-deps.sh
sudo ./install-cross-tools.sh
sudo .github/workflows/install-extras.sh
- name: build
run: |
mkdir build
cd build
cmake ..
cmake --build . -j$(nproc)
- run: cd build; ctest --output-on-failure -j$(nproc)
- name: archive test results
uses: actions/upload-artifact@v7
if: failure()
with:
name: test-results-multi-archs
path: |
build
!build/CMakeFiles
build-distros:
strategy:
matrix:
distro:
- alpine
- archlinux
- debian:11 # GCC 10 and CMake 3.18 - the minimum supported by mold
- fedora
- gentoo/stage3
- opensuse/tumbleweed
- ubuntu:22.04
- ubuntu:25.04
runs-on: ubuntu-latest
timeout-minutes: 60
container: ${{ matrix.distro }}
steps:
- uses: actions/checkout@v6
- run: ./install-build-deps.sh
- name: build
run: |
mkdir build
cd build
cmake ..
cmake --build . -j$(nproc)
- run: cd build; ctest --output-on-failure -j$(nproc)
- name: sanitize distro name
if: failure()
id: sanitize
run: echo "name=$(echo '${{ matrix.distro }}' | tr '/:' '--')" >> "$GITHUB_OUTPUT"
- name: archive test results
uses: actions/upload-artifact@v7
if: failure()
with:
name: test-results-${{ steps.sanitize.outputs.name }}
path: |
build
!build/CMakeFiles
build-macos:
runs-on: macos-latest
timeout-minutes: 60
steps:
- uses: actions/checkout@v6
- name: build
run: |
mkdir build
cd build
cmake ..
cmake --build . -j$(sysctl -n hw.physicalcpu)
build-windows:
runs-on: windows-latest
timeout-minutes: 60
steps:
- uses: actions/checkout@v6
- name: build
run: |
mkdir build
cd build
cmake -T clangcl ..
cmake --build . -j $Env:NUMBER_OF_PROCESSORS
build-msys:
runs-on: windows-latest
timeout-minutes: 60
steps:
- uses: actions/checkout@v6
- name: Setup MSYS2
uses: msys2/setup-msys2@v2
with:
msystem: UCRT64
update: true
pacboy: gcc-libs:p libwinpthread-git:p tbb:p zlib:p zstd:p dlfcn:p cc:p cmake:p ninja:p
- name: build
shell: msys2 {0}
run: |
mkdir build
cd build
cmake -GNinja -DMOLD_USE_MIMALLOC=OFF -DMOLD_USE_SYSTEM_TBB=ON ..
cmake --build . -j $(nproc)
build-freebsd:
runs-on: ubuntu-latest
timeout-minutes: 60
steps:
- uses: actions/checkout@v6
- name: Build and test
uses: vmactions/freebsd-vm@v1
with:
usesh: true
run: |
./install-build-deps.sh
mkdir build
cd build
cmake ..
cmake --build . -j$(nproc)
ctest --output-on-failure -j$(nproc)
- uses: actions/checkout@v2
- name: apt-get
run: sudo dpkg --add-architecture i386 && sudo apt-get update && sudo apt-get install build-essential libstdc++-10-dev cmake clang libssl-dev zlib1g-dev libxxhash-dev libtbb-dev git dwarfdump libc6-dev:i386 lib32gcc-10-dev gcc-multilib
- name: make
run: make -j$(nproc)
- name: make test
run: make test
-75
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@@ -1,75 +0,0 @@
#!/bin/bash -x
apt-get update
apt-get install -y wget xz-utils
# Install a 32-bit RISC-V toolchain
mkdir /rv32
wget -O- --progress=dot:mega https://github.com/riscv-collab/riscv-gnu-toolchain/releases/download/2025.06.13/riscv32-glibc-ubuntu-24.04-gcc-nightly-2025.06.13-nightly.tar.xz | tar -C /rv32 --strip-components=1 --xz -xf -
ln -sf /rv32/sysroot /usr/riscv32-linux-gnu
echo '/rv32/bin/riscv32-unknown-linux-gnu-gcc -L/usr/riscv32-linux-gnu "$@"' > /usr/bin/riscv32-linux-gnu-gcc
echo '/rv32/bin/riscv32-unknown-linux-gnu-g++ -L/usr/riscv32-linux-gnu "$@"' > /usr/bin/riscv32-linux-gnu-g++
chmod 755 /usr/bin/riscv32-linux-gnu-{gcc,g++}
for i in objdump objcopy strip; do
ln -sf /rv32/bin/riscv32-unknown-linux-gnu-$i /usr/bin/riscv32-linux-gnu-$i
done
# Install a LoongArch toolchain
mkdir /larch
wget -O- --progress=dot:mega https://github.com/loongson/build-tools/releases/download/2025.06.06/x86_64-cross-tools-loongarch64-binutils_2.44-gcc_15.1.0-glibc_2.41.tar.xz | tar -C /larch --strip-components=1 --xz -xf -
cp -r /larch/loongarch64-unknown-linux-gnu/lib/* /larch/target/lib64
ln -sf /larch/target /usr/loongarch64-linux-gnu
for i in gcc g++ objdump objcopy strip; do
ln -sf /larch/bin/loongarch64-unknown-linux-gnu-$i /usr/bin/loongarch64-linux-gnu-$i
done
wget -O /usr/local/bin/qemu-loongarch64 --progress=dot:mega https://github.com/loongson/build-tools/releases/download/2025.06.06/qemu-loongarch64
chmod 755 /usr/local/bin/qemu-loongarch64
# Install ARM32 big-endian toolchain
mkdir /armeb
wget -O- --progress=dot:mega https://toolchains.bootlin.com/downloads/releases/toolchains/armebv7-eabihf/tarballs/armebv7-eabihf--glibc--stable-2024.05-1.tar.xz | tar -C /armeb --strip-components=1 --xz -xf -
ln -sf /armeb/armeb-buildroot-linux-gnueabihf/sysroot /usr/armeb-linux-gnueabihf
echo '/armeb/bin/armeb-linux-gcc -L/usr/armeb-linux-gnu "$@"' > /usr/bin/armeb-linux-gnueabihf-gcc
echo '/armeb/bin/armeb-linux-g++ -L/usr/armeb-linux-gnu "$@"' > /usr/bin/armeb-linux-gnueabihf-g++
chmod 755 /usr/bin/armeb-linux-gnueabihf-{gcc,g++}
for i in objdump objcopy strip; do
ln -sf /armeb/bin/armeb-linux-$i /usr/bin/armeb-linux-gnueabihf-$i
done
# Install ARM64 big-endian toolchain
mkdir /aarch64be
wget -O- --progress=dot:mega https://toolchains.bootlin.com/downloads/releases/toolchains/aarch64be/tarballs/aarch64be--glibc--stable-2024.05-1.tar.xz | tar -C /aarch64be --strip-components=1 --xz -xf -
ln -sf /aarch64be/aarch64_be-buildroot-linux-gnu/sysroot /usr/aarch64_be-linux-gnu
echo '/aarch64be/bin/aarch64_be-linux-gcc -L/usr/aarch64_be-linux-gnu "$@"' > /usr/bin/aarch64_be-linux-gnu-gcc
echo '/aarch64be/bin/aarch64_be-linux-g++ -L/usr/aarch64_be-linux-gnu "$@"' > /usr/bin/aarch64_be-linux-gnu-g++
chmod 755 /usr/bin/aarch64_be-linux-gnu-{gcc,g++}
for i in objdump objcopy strip; do
ln -sf /aarch64be/bin/aarch64_be-linux-$i /usr/bin/aarch64_be-linux-gnu-$i
done
# Install SH4 big-endian toolchain
mkdir /sh4aeb
wget -O- --progress=dot:mega https://toolchains.bootlin.com/downloads/releases/toolchains/sh-sh4aeb/tarballs/sh-sh4aeb--glibc--stable-2024.05-1.tar.xz | tar -C /sh4aeb --strip-components=1 --xz -xf -
ln -sf /sh4aeb/sh4aeb-buildroot-linux-gnu/sysroot /usr/sh4aeb-linux-gnu
echo '/sh4aeb/bin/sh4aeb-linux-gcc -L/usr/sh4aeb-linux-gnu "$@"' > /usr/bin/sh4aeb-linux-gnu-gcc
echo '/sh4aeb/bin/sh4aeb-linux-g++ -L/usr/sh4aeb-linux-gnu "$@"' > /usr/bin/sh4aeb-linux-gnu-g++
chmod 755 /usr/bin/sh4aeb-linux-gnu-{gcc,g++}
for i in objdump objcopy strip; do
ln -sf /sh4aeb/bin/sh4aeb-linux-$i /usr/bin/sh4aeb-linux-gnu-$i
done
# Install Intel SDE CPU emulator for CET-related tests
mkdir /sde
wget -O- --progress=dot:mega https://downloadmirror.intel.com/850782/sde-external-9.53.0-2025-03-16-lin.tar.xz | tar -C /sde --strip-components=1 --xz -xf -
ln -s /sde/sde64 /usr/bin
-104
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@@ -1,104 +0,0 @@
name: Build & attach tarballs on tag push
on:
push:
tags: ['v[0-9]*']
permissions:
contents: write
packages: write
id-token: write
env:
TAG: ${{ github.ref_name }}
jobs:
build-linux:
strategy:
matrix:
include:
- { target: x86_64, os: ubuntu-24.04 }
- { target: aarch64, os: ubuntu-24.04-arm }
- { target: arm, os: ubuntu-24.04-arm }
- { target: riscv64, os: ubuntu-24.04 }
- { target: ppc64le, os: ubuntu-24.04 }
- { target: s390x, os: ubuntu-24.04 }
- { target: loongarch64, os: ubuntu-24.04 }
runs-on: ${{ matrix.os }}
steps:
- uses: actions/checkout@v6
- name: Install Podman
run: sudo apt-get update && sudo apt-get install -y podman qemu-user-static
- name: Login to GitHub Container Registry
uses: redhat-actions/podman-login@v1
with:
registry: ghcr.io
username: ${{ github.repository_owner }}
password: ${{ secrets.GITHUB_TOKEN }}
- run: ./dist.sh ${{ matrix.target }}
- uses: actions/upload-artifact@v7
with:
name: ${{ matrix.target }}
path: dist/mold-*.tar.gz
build-windows:
runs-on: windows-latest
steps:
- uses: actions/checkout@v6
- name: Build and Archive
shell: pwsh
run: |
mkdir build
cd build
cmake -T clangcl ..
cmake --build . --config Release -j $Env:NUMBER_OF_PROCESSORS
cmake --install . --config Release --prefix ../mold-install
cd ..
New-Item -ItemType Directory -Force dist | Out-Null
$version = $Env:TAG -replace '^v', ''
Compress-Archive -Path mold-install\* -DestinationPath dist\mold-$version-x86_64-windows.zip
- uses: actions/upload-artifact@v7
with:
name: win-x86_64
path: dist/mold-*.*
publish:
needs: [build-linux, build-windows]
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v6
- uses: actions/download-artifact@v8
with:
path: dist
pattern: '*'
merge-multiple: true
- name: Ensure release exists (create if missing)
env:
GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
run: |
set -e
if gh release view "$TAG" >& /dev/null; then
echo "Existing release found for $TAG"
else
echo "Creating draft release for $TAG"
gh release create "$TAG" --draft \
--title "$TAG" \
--notes "Automated draft – fill the changelog later."
fi
- name: Upload tarballs
env:
GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
run: |
gh release upload "$TAG" dist/* --clobber
gh release view "$TAG" --json assets --jq '.assets[].name'
-37
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@@ -1,37 +0,0 @@
#!/bin/bash
set -e -x
cd "$(dirname $0)"/../..
if [ "$GITHUB_REPOSITORY" = '' ]; then
image=mold-msan
image_build="podman build -t $image -"
else
# If this script is running on GitHub Actions, we want to cache
# the created container image in GitHub's container repostiory.
image=ghcr.io/$GITHUB_REPOSITORY/mold-msan
image_build="podman build -t $image --output=type=registry --layers --cache-to $image --cache-from $image -"
fi
cat <<EOF | $image_build
FROM mirror.gcr.io/library/ubuntu:24.04
RUN apt-get update && \
apt-get install -y --no-install-recommends build-essential gcc g++ wget ca-certificates make cmake ninja-build python3 clang-20 llvm-20-dev libclang-20-dev libclang-rt-20-dev libtbb-dev mold && \
rm -rf /var/lib/apt/lists
RUN mkdir /llvm && \
cd /llvm && \
wget -O- --progress=dot:mega https://github.com/llvm/llvm-project/archive/refs/tags/llvmorg-21.1.1.tar.gz | tar xzf - --strip-components=1 && \
cmake -S ./runtimes -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_RUNTIMES='libcxx;libcxxabi;libunwind' -DCMAKE_C_COMPILER=clang-20 -DCMAKE_CXX_COMPILER=clang++-20 -DLLVM_USE_SANITIZER=MemoryWithOrigins && \
cmake --build build -j\$(nproc) && \
cmake --install build --prefix /msan && \
rm -rf /llvm
EOF
# Build mold and run its tests
podman run -it --rm --pull=never -v "$(pwd):/mold:ro" --security-opt seccomp=unconfined $image bash -c "
set -e
mkdir /build
cd /build
cmake -GNinja -DCMAKE_BUILD_TYPE=Debug -DCMAKE_C_COMPILER=clang-20 -DCMAKE_CXX_COMPILER=clang++-20 -DMOLD_USE_MSAN=ON -DMOLD_STDLIB_PREFIX=/msan -DMOLD_USE_MIMALLOC=0 -DMOLD_USE_SYSTEM_TBB=1 -DMOLD_USE_MOLD=1 /mold
cmake --build . -j\$(nproc)
setarch -R ctest --output-on-failure -j\$(nproc)
"
-33
View File
@@ -1,33 +0,0 @@
name: Update manpage
on:
push:
paths:
- 'docs/mold.md'
branches:
- main
workflow_dispatch:
jobs:
update-manpage:
runs-on: ubuntu-latest
steps:
- name: Check out repository
uses: actions/checkout@v6
- name: Install ronn
run: sudo apt-get update && sudo apt-get install -y ronn
- name: Generate mold.1 from mold.md
run: ronn --roff docs/mold.md
- name: Configure Git
run: |
git config --global user.name 'Rui Ueyama'
git config --global user.email '[email protected]'
- name: Commit and push if mold.1 is updated
run: |
git add docs/mold.1
git diff --staged --quiet || (git commit -m "Update mold.1 (automated commit)" && git push)
+6 -7
View File
@@ -1,11 +1,10 @@
*.o
*.so
*~
**/.DS_Store
.cache
core
gentoo
/mold-*.tar.gz
/build*
/mold
/dist
/test/tmp
options.inc
core
ld
oneTBB
gentoo
File renamed without changes.
-493
View File
@@ -1,493 +0,0 @@
# You can customize a build by specifying CMake options. An option may be
# given in the -Dvariable=value form. For a boolean variable, `ON` or `1`
# means true, while `OFF` or `0` means false.
#
# Here are a couple of common cmake options:
#
# -DCMAKE_C_COMPILER=<command-name>
#
# Specifies the C compiler name to use. The default value is `cc`.
#
# -DCMAKE_CXX_COMPILER=<command-name>
#
# Specifies the C++ compiler name to use. The default value is `c++`.
#
# -DCMAKE_INSTALL_PREFIX=<directory>
#
# Specifies the install target directory. The default value is `/usr/local`.
#
# -DCMAKE_BUILD_TYPE=[Debug | Release | RelWithDebInfo | MinSizeRel]
#
# Specifies the build type. The default is `Release`, which is the right
# option unless you are debugging mold.
#
# An example of a cmake command line is shown below:
#
# $ cmake -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_CXX_COMPILER=g++-12 ..
#
# where `..` refers to this directory.
#
# With cmake, you may run `cmake --install .` instead of `make install` to
# install build artifacts to system directories. If you want to install
# artifacts to a temporary target directory, run `cmake --install . --prefix
# <dir>`.
#
# You can see the current cmake variables and their values by running
# `cmake -N -L .` in a build directory.
#
# Note that in this file, we provide various dials and knobs to configure
# how to build mold. However, as a policy, we do not provide a way to
# enable/disable any individual mold's feature. In other words, we do not
# provide options like `--enable-foo` or `--disable-foo`. The motivation
# behind this is build reproducibility. We want to guarantee that all builds
# of the mold linker of the same version will have the exact same set of
# features and behave exactly the same.
cmake_minimum_required(VERSION 3.14)
project(mold VERSION 2.41.0)
include(CMakeDependentOption)
include(CheckSymbolExists)
include(GNUInstallDirs)
add_executable(mold)
target_compile_features(mold PRIVATE cxx_std_20)
if(MINGW)
target_link_libraries(mold PRIVATE dl)
else()
target_link_libraries(mold PRIVATE ${CMAKE_DL_LIBS})
endif()
# Build mold itself using mold if -DMOLD_USE_MOLD=ON
option(MOLD_USE_MOLD "Use mold to build mold" OFF)
if(MOLD_USE_MOLD)
target_link_options(mold PRIVATE -fuse-ld=mold)
if(CMAKE_BUILD_TYPE MATCHES "Deb")
target_link_options(mold PRIVATE -Wl,--gdb-index)
endif()
if(CMAKE_BUILD_TYPE MATCHES "^Rel")
target_link_options(mold PRIVATE -Wl,--gc-sections,--icf=safe)
endif()
endif()
if(NOT "${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "MSVC")
target_compile_options(mold PRIVATE
-fno-exceptions
-fno-unwind-tables
-fno-asynchronous-unwind-tables
-ffunction-sections
-fdata-sections
-Wall
-Wextra
-Wno-sign-compare
-Wno-unused-function
-Wno-unused-parameter
-Wno-missing-field-initializers
-ggnu-pubnames)
endif()
if(CMAKE_BUILD_TYPE STREQUAL "Debug")
target_compile_options(mold PRIVATE -D_GLIBCXX_ASSERTIONS)
endif()
if(CMAKE_SYSTEM_NAME STREQUAL "OpenBSD")
set(OPENBSD ON)
endif()
# Build mold with -flto if -DMOLD_LTO=ON
option(MOLD_LTO "Build mold with link-time optimization enabled")
if(MOLD_LTO)
set_property(TARGET mold PROPERTY INTERPROCEDURAL_OPTIMIZATION ON)
endif()
# Enable AddressSanitizer if -DMOLD_USE_ASAN=ON
option(MOLD_USE_ASAN "Build mold with AddressSanitizer" OFF)
if(MOLD_USE_ASAN)
target_compile_options(mold PRIVATE -fsanitize=address -fsanitize=undefined)
target_link_options(mold PRIVATE -fsanitize=address -fsanitize=undefined)
endif()
# Enabled ThreadSanitizer if -DMOLD_USE_TSAN=ON
option(MOLD_USE_TSAN "Build mold with ThreadSanitizer" OFF)
if(MOLD_USE_TSAN)
target_compile_options(mold PRIVATE -fsanitize=thread)
target_link_options(mold PRIVATE -fsanitize=thread)
endif()
# Enable MemorySanitizer if -DMOLD_USE_MSAN=ON
option(MOLD_USE_MSAN "Build mold with MemorySanitizer" OFF)
if(MOLD_USE_MSAN)
set(MOLD_STDLIB_PREFIX /usr CACHE FILEPATH "prefix of instrumented stdlib")
target_compile_options(mold PRIVATE
-g -Og -fsanitize=memory -fsanitize-memory-track-origins
-nostdinc++ -isystem ${MOLD_STDLIB_PREFIX}/include/c++/v1
-DENABLE_MSAN_UNPOISON
)
target_link_options(mold PRIVATE
-fsanitize=memory
-nostdlib++ -L ${MOLD_STDLIB_PREFIX}/lib -lc++
-Wl,-rpath,${MOLD_STDLIB_PREFIX}/lib
)
endif()
# Statically-link libstdc++ if -DMOLD_MOSTLY_STATIC=ON.
#
# This option is intended to be used by `./dist.sh` script to create a
# mold binary that works on various Linux distros. You probably don't
# need nor want to set this to ON.
option(MOLD_MOSTLY_STATIC "Statically link libstdc++ and some other libraries" OFF)
if(MOLD_MOSTLY_STATIC)
target_link_options(mold PRIVATE -static-libstdc++)
endif()
# Find zlib. If libz.so is not found, we compile a bundled one and
# statically-link it to mold.
find_package(ZLIB QUIET)
if(ZLIB_FOUND AND NOT MOLD_MOSTLY_STATIC)
target_link_libraries(mold PRIVATE ZLIB::ZLIB)
else()
set(ZLIB_BUILD_EXAMPLES OFF CACHE INTERNAL "")
add_subdirectory(third-party/zlib EXCLUDE_FROM_ALL)
target_include_directories(zlibstatic INTERFACE third-party/zlib
$<TARGET_PROPERTY:zlibstatic,BINARY_DIR>)
target_link_libraries(mold PRIVATE zlibstatic)
endif()
# Find BLAKE3 cryptographic hash library. Just like zlib, if libblkae3.so
# is not found, we compile a bundled one and statically-link it to mold.
find_package(BLAKE3 QUIET)
if(BLAKE3_FOUND AND NOT MOLD_MOSTLY_STATIC)
target_link_libraries(mold PRIVATE BLAKE3::blake3)
else()
function(mold_add_blake3)
set(BUILD_SHARED_LIBS OFF)
add_subdirectory(third-party/blake3/c EXCLUDE_FROM_ALL)
target_link_libraries(mold PRIVATE blake3)
target_include_directories(mold PUBLIC third-party/blake3/c)
endfunction()
mold_add_blake3()
endif()
# Find zstd compression library. If zstd.h is not found, we compile a
# bundled one and statically-link it to mold.
include(CheckIncludeFile)
check_include_file(zstd.h HAVE_ZSTD_H)
if(HAVE_ZSTD_H AND NOT MOLD_MOSTLY_STATIC)
target_link_libraries(mold PRIVATE zstd)
else()
set(ZSTD_BUILD_PROGRAMS OFF)
set(ZSTD_BUILD_CONTRIB OFF)
set(ZSTD_BUILD_TESTS OFF)
set(ZSTD_MULTITHREAD_SUPPORT OFF)
set(ZSTD_BUILD_SHARED OFF)
set(ZSTD_BUILD_STATIC ON)
add_subdirectory(third-party/zstd/build/cmake EXCLUDE_FROM_ALL)
target_include_directories(mold PUBLIC third-party/zstd/lib)
target_link_libraries(mold PRIVATE libzstd_static)
endif()
# Find mimalloc. mimalloc is an alternative malloc implementation
# optimized for multi-threaded applications.
#
# If you want to use the usual libc's malloc, pass -DMOLD_USE_MIMALLOC=OFF.
#
# We enable mimalloc by default for 64-bit targets. It doesn't seem to
# be stable on 32-bit targets.
cmake_dependent_option(
MOLD_USE_MIMALLOC "Use mimalloc" ON
"CMAKE_SIZEOF_VOID_P EQUAL 8; NOT APPLE; NOT ANDROID; NOT OPENBSD; NOT MOLD_USE_ASAN; NOT MOLD_USE_TSAN" OFF)
cmake_dependent_option(
MOLD_USE_SYSTEM_MIMALLOC "Use system or vendored mimalloc" OFF
MOLD_USE_MIMALLOC OFF)
# By default, we build a bundled mimalloc and statically-link it to
# mold. If you want to dynamically link to the system's
# libmimalloc.so, pass -DMOLD_USE_SYSTEM_MIMALLOC=ON.
if(MOLD_USE_MIMALLOC)
if(MOLD_USE_SYSTEM_MIMALLOC)
find_package(mimalloc REQUIRED)
target_link_libraries(mold PRIVATE mimalloc)
else()
function(mold_add_mimalloc)
set(MI_BUILD_STATIC ON CACHE INTERNAL "")
set(MI_BUILD_TESTS OFF CACHE INTERNAL "")
set(MI_NO_OPT_ARCH ON CACHE INTERNAL "")
add_subdirectory(third-party/mimalloc EXCLUDE_FROM_ALL)
target_compile_definitions(mimalloc-static PRIVATE MI_USE_ENVIRON=0)
target_link_libraries(mold PRIVATE mimalloc-static)
endfunction()
mold_add_mimalloc()
endif()
endif()
# Find TBB. TBB (OneTBB or Intel TBB) is a high-level threading library.
# Use of this library is mandatory.
#
# By default, we build a bundled one and statically-link the library
# to mold. If you want to link to the system's libtbb2.so, pass
# -DMOLD_USE_SYSTEM_TBB=ON.
option(MOLD_USE_SYSTEM_TBB "Use system or vendored TBB" OFF)
if(MOLD_USE_SYSTEM_TBB OR BLAKE3_USE_TBB)
find_package(TBB REQUIRED)
target_link_libraries(mold PRIVATE TBB::tbb)
else()
function(mold_add_tbb)
set(BUILD_SHARED_LIBS OFF)
set(TBB_TEST OFF CACHE INTERNAL "")
set(TBB_STRICT OFF CACHE INTERNAL "")
add_subdirectory(third-party/tbb EXCLUDE_FROM_ALL)
target_compile_definitions(tbb PRIVATE __TBB_DYNAMIC_LOAD_ENABLED=0)
target_link_libraries(mold PRIVATE TBB::tbb)
endfunction()
mold_add_tbb()
endif()
# We always use Clang to build mold on Windows. MSVC can't compile mold.
if(WIN32)
if(MSVC AND NOT CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
message(FATAL_ERROR
"Your compiler is not supported; install Clang from Visual Studio Installer and re-run cmake with '-T clangcl'")
endif()
target_compile_definitions(mold PRIVATE NOGDI NOMINMAX)
if(MINGW)
target_compile_definitions(mold PRIVATE _WIN32_WINNT=0xA00)
target_link_libraries(mold PRIVATE bcrypt)
endif()
else()
include(CheckLibraryExists)
check_library_exists(m pow "" LIBM_FOUND)
if(LIBM_FOUND)
target_link_libraries(mold PRIVATE m)
endif()
endif()
# Build mold-wrapper.so
if(NOT APPLE AND NOT WIN32)
add_library(mold-wrapper SHARED)
install(TARGETS mold-wrapper DESTINATION ${CMAKE_INSTALL_LIBDIR}/mold)
# Remove the default `lib` prefix
set_target_properties(mold-wrapper PROPERTIES PREFIX "")
target_link_libraries(mold-wrapper PRIVATE ${CMAKE_DL_LIBS})
target_sources(mold-wrapper PRIVATE src/mold-wrapper.c)
endif()
# If atomics doesn't work by default, add -latomic.
# We need the flag on riscv, armv6 and m68k.
include(CheckCXXSourceCompiles)
check_cxx_source_compiles("#include <atomic>
int main() {
std::atomic_uint8_t a;
std::atomic_uint16_t b;
std::atomic_uint32_t c;
std::atomic_uint64_t d;
return ++a + ++b + ++c + ++d;
}" HAVE_FULL_ATOMIC_SUPPORT)
if(NOT HAVE_FULL_ATOMIC_SUPPORT)
target_link_libraries(mold PRIVATE atomic)
endif()
# Add -pthread
if(NOT APPLE AND NOT MSVC)
target_compile_options(mold PRIVATE -pthread)
target_link_options(mold PRIVATE -pthread)
endif()
check_symbol_exists(madvise sys/mman.h HAVE_MADVISE)
check_symbol_exists(uname sys/utsname.h HAVE_UNAME)
# Create a .cc file containing the current git hash for `mold --version`.
add_custom_target(git_hash
COMMAND ${CMAKE_COMMAND}
-DSOURCE_DIR=${CMAKE_SOURCE_DIR}
-DOUTPUT_FILE=${CMAKE_BINARY_DIR}/mold-git-hash.h
-P ${CMAKE_SOURCE_DIR}/lib/update-git-hash.cmake
DEPENDS lib/update-git-hash.cmake
BYPRODUCTS mold-git-hash.h
VERBATIM)
add_dependencies(mold git_hash)
# Almost all functions are template in mold which take a target type
# (e.g. X86_64) as its type parameter. Since we suport more than 10
# targets, compiling a single source file for all the targets is very
# slow.
#
# As a workaround, we create a .cc file for each target and spawn many
# compiler instances. This is hacky but greatly reduces compile time
# on a multicore machine.
#
# You can build mold for a specific set of targets by passing, e.g.,
# -DMOLD_TARGETS='X86_64;ARM64LE', though this is strongly discouraged
# for build reproducibility. Use this option only if you build mold
# frequently for your personal use; otherwise, always build mold with all
# targets enabled. We provide this flag in the trust that you will not
# abuse it, so please don’t betray that trust.
set(MOLD_TARGETS
X86_64 I386 ARM64LE ARM64BE ARM32LE ARM32BE RV32LE RV32BE RV64LE
RV64BE PPC32 PPC64V1 PPC64V2 S390X SPARC64 M68K SH4LE SH4BE
LOONGARCH32 LOONGARCH64
CACHE STRING "List of supported targets")
list(GET MOLD_TARGETS 0 MOLD_FIRST_TARGET)
list(APPEND MOLD_TEMPLATE_FILES
src/arch-arm32.cc
src/arch-arm64.cc
src/arch-i386.cc
src/arch-loongarch.cc
src/arch-m68k.cc
src/arch-ppc32.cc
src/arch-ppc64v1.cc
src/arch-ppc64v2.cc
src/arch-riscv.cc
src/arch-s390x.cc
src/arch-sh4.cc
src/arch-sparc64.cc
src/arch-x86-64.cc
src/archive-file.cc
src/cmdline.cc
src/error.cc
src/filetype.cc
src/gc-sections.cc
src/gdb-index.cc
src/icf.cc
src/input-files.cc
src/input-sections.cc
src/linker-script.cc
src/main.cc
src/mapfile.cc
src/output-chunks.cc
src/passes.cc
src/relocatable.cc
src/shrink-sections.cc
src/thunks.cc
src/tls.cc
)
if(WIN32 AND NOT MINGW)
list(APPEND MOLD_TEMPLATE_FILES src/lto-win32.cc)
else()
list(APPEND MOLD_TEMPLATE_FILES src/lto-unix.cc)
endif()
if(WIN32)
list(APPEND MOLD_TEMPLATE_FILES
src/output-file-win32.cc
src/subprocess-win32.cc
)
else()
list(APPEND MOLD_TEMPLATE_FILES
src/output-file-unix.cc
src/subprocess-unix.cc
)
endif()
function(mold_instantiate_templates SOURCE TARGET)
set(PATH ${CMAKE_BINARY_DIR}/${SOURCE}.${TARGET}.cc)
if(NOT EXISTS ${PATH})
file(WRITE ${PATH} "#define MOLD_${TARGET} 1
#define MOLD_TARGET ${TARGET}
#include \"${CMAKE_SOURCE_DIR}/${SOURCE}\"
")
endif()
target_sources(mold PRIVATE ${PATH})
endfunction()
foreach (SOURCE IN LISTS MOLD_TEMPLATE_FILES)
foreach(TARGET IN LISTS MOLD_TARGETS)
mold_instantiate_templates(${SOURCE} ${TARGET})
set(HAVE_TARGET_${TARGET} 1)
endforeach()
endforeach()
# Add other non-template source files.
target_sources(mold PRIVATE
lib/aho-corasick.cc
lib/compress.cc
lib/crc32.cc
lib/demangle.cc
lib/filepath.cc
lib/glob.cc
lib/hyperloglog.cc
lib/perf.cc
lib/random.cc
lib/tar.cc
src/elf.cc
src/entry.cc
third-party/rust-demangle/rust-demangle.c
)
if(WIN32)
target_sources(mold PRIVATE
src/jobs-win32.cc
src/mapped-file-win32.cc
src/signal-win32.cc
)
else()
target_sources(mold PRIVATE
src/jobs-unix.cc
src/mapped-file-unix.cc
src/signal-unix.cc
)
endif()
# Create config.h file
configure_file(lib/config.h.in config.h)
include_directories(${CMAKE_CURRENT_BINARY_DIR})
# Test configs
include(CTest)
if(BUILD_TESTING)
# Create the ld symlinks required for testing
if(NOT WIN32)
add_custom_command(
TARGET mold POST_BUILD
COMMAND ${CMAKE_COMMAND} -E create_symlink mold ld
BYPRODUCTS ld
WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
VERBATIM)
endif()
if(${UNIX})
add_subdirectory(test)
endif()
endif()
if(NOT CMAKE_SKIP_INSTALL_RULES)
install(TARGETS mold RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
install(FILES docs/mold.1 DESTINATION ${CMAKE_INSTALL_MANDIR}/man1/)
install(FILES LICENSE DESTINATION ${CMAKE_INSTALL_DOCDIR})
function(mold_install_relative_symlink OLD NEW)
install(CODE "
get_filename_component(PREFIX_ABS \${CMAKE_INSTALL_PREFIX}/ ABSOLUTE)
get_filename_component(OLD_ABS ${OLD} ABSOLUTE BASE_DIR \${PREFIX_ABS})
get_filename_component(NEW_ABS ${NEW} ABSOLUTE BASE_DIR \${PREFIX_ABS})
get_filename_component(NEW_DIR \${NEW_ABS} DIRECTORY)
file(RELATIVE_PATH OLD_REL \${NEW_DIR} \${OLD_ABS})
message(STATUS \"Installing symlink: \$ENV{DESTDIR}\${NEW_ABS} -> \${OLD_REL}\")
file(MAKE_DIRECTORY \$ENV{DESTDIR}\${NEW_DIR})
file(CREATE_LINK \${OLD_REL} \$ENV{DESTDIR}\${NEW_ABS} SYMBOLIC)")
endfunction()
if(NOT WIN32)
mold_install_relative_symlink(${CMAKE_INSTALL_BINDIR}/mold${CMAKE_EXECUTABLE_SUFFIX}
${CMAKE_INSTALL_LIBEXECDIR}/mold/ld${CMAKE_EXECUTABLE_SUFFIX})
mold_install_relative_symlink(${CMAKE_INSTALL_BINDIR}/mold${CMAKE_EXECUTABLE_SUFFIX}
${CMAKE_INSTALL_BINDIR}/ld.mold${CMAKE_EXECUTABLE_SUFFIX})
mold_install_relative_symlink(${CMAKE_INSTALL_MANDIR}/man1/mold.1
${CMAKE_INSTALL_MANDIR}/man1/ld.mold.1)
endif()
endif()
+54
View File
@@ -0,0 +1,54 @@
# Contributing to mold
Summary: When you send a patch, you must agree that the patch is
released under the dual license of the GNU AGPLv3 and the MIT license.
As an indication of agreement, please add a `Signed-off-by` line to
your commit message using `git commit -s`.
Here is the long official version:
mold is currently licensed under the GNU AGPLv3, but I want to relicense
it under a more liberal license in the future. To make this possible,
I want all patches to be submitted under the dual license of the GNU
AGPLv3 and the MIT license (the "Dual License") from the beginning.
To make it clear that contributors have agreed to release their
patches under the Dual License, I introduced a sign-off procedure just
like the Linux kernel project did. The sign-off is a simple line at
the end of the git commit message, which certifies that you wrote it
or otherwise have the right to pass it on as an open-source patch. The
rules are pretty simple: if you can certify the below:
> ## Developer's Certificate of Origin
>
> By making a contribution to this project, I certify that:
>
> 1. The contribution was created in whole or in part by me and I
> have the right to submit it under the Dual License; or
>
> 2. The contribution is based upon previous work that, to the best
> of my knowledge, is covered under the the Dual License and I
> have the right under the Dual License to submit that work with
> modifications, whether created in whole or in part by me, under
> the Dual License (unless I am permitted to submit under
> different licenses), as indicated in the file; or
>
> 3. The contribution was provided directly to me by some other
> person who certified (1), (2) or (3) and I have not modified it.
>
> 4. I understand and agree that this project and the contribution
> are public and that a record of the contribution (including all
> personal information I submit with it, including my sign-off) is
> maintained indefinitely and may be redistributed consistent with
> this project or the open source license(s) involved.
then you just add a line saying:
```
Signed-off-by: Random J Developer <[email protected]>
```
using your real name (sorry, no pseudonyms or anonymous contributions.)
This will be done for you automatically if you use ``git commit -s``.
Reverts should also include "Signed-off-by". ``git revert -s`` does that
for you.
+667 -17
View File
@@ -1,21 +1,671 @@
MIT License
Note: I'm looking for a sponsor who wants to purchase the copyright
of this work and relicense it under a more liberal license such as
the MIT license. For now, mold is released under the GNU AGPL v3.
Copyright (c) 2023 Rui Ueyama
If you just want to use mold but do not want to use AGPL software
in your organization, a commercial license is available. Please
contact [email protected].
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
--
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
GNU AFFERO GENERAL PUBLIC LICENSE
Version 3, 19 November 2007
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
The GNU Affero General Public License is a free, copyleft license for
software and other kinds of works, specifically designed to ensure
cooperation with the community in the case of network server software.
The licenses for most software and other practical works are designed
to take away your freedom to share and change the works. By contrast,
our General Public Licenses are intended to guarantee your freedom to
share and change all versions of a program--to make sure it remains free
software for all its users.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
them if you wish), that you receive source code or can get it if you
want it, that you can change the software or use pieces of it in new
free programs, and that you know you can do these things.
Developers that use our General Public Licenses protect your rights
with two steps: (1) assert copyright on the software, and (2) offer
you this License which gives you legal permission to copy, distribute
and/or modify the software.
A secondary benefit of defending all users' freedom is that
improvements made in alternate versions of the program, if they
receive widespread use, become available for other developers to
incorporate. Many developers of free software are heartened and
encouraged by the resulting cooperation. However, in the case of
software used on network servers, this result may fail to come about.
The GNU General Public License permits making a modified version and
letting the public access it on a server without ever releasing its
source code to the public.
The GNU Affero General Public License is designed specifically to
ensure that, in such cases, the modified source code becomes available
to the community. It requires the operator of a network server to
provide the source code of the modified version running there to the
users of that server. Therefore, public use of a modified version, on
a publicly accessible server, gives the public access to the source
code of the modified version.
An older license, called the Affero General Public License and
published by Affero, was designed to accomplish similar goals. This is
a different license, not a version of the Affero GPL, but Affero has
released a new version of the Affero GPL which permits relicensing under
this license.
The precise terms and conditions for copying, distribution and
modification follow.
TERMS AND CONDITIONS
0. Definitions.
"This License" refers to version 3 of the GNU Affero General Public License.
"Copyright" also means copyright-like laws that apply to other kinds of
works, such as semiconductor masks.
"The Program" refers to any copyrightable work licensed under this
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To "modify" a work means to copy from or adapt all or part of the work
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A "covered work" means either the unmodified Program or a work based
on the Program.
To "propagate" a work means to do anything with it that, without
permission, would make you directly or secondarily liable for
infringement under applicable copyright law, except executing it on a
computer or modifying a private copy. Propagation includes copying,
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public, and in some countries other activities as well.
To "convey" a work means any kind of propagation that enables other
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An interactive user interface displays "Appropriate Legal Notices"
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feature that (1) displays an appropriate copyright notice, and (2)
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work under this License, and how to view a copy of this License. If
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1. Source Code.
The "source code" for a work means the preferred form of the work
for making modifications to it. "Object code" means any non-source
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implementation is available to the public in source code form. A
"Major Component", in this context, means a major essential component
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The "Corresponding Source" for a work in object code form means all
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which are not part of the work. For example, Corresponding Source
includes interface definition files associated with source files for
the work, and the source code for shared libraries and dynamically
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such as by intimate data communication or control flow between those
subprograms and other parts of the work.
The Corresponding Source need not include anything that users
can regenerate automatically from other parts of the Corresponding
Source.
The Corresponding Source for a work in source code form is that
same work.
2. Basic Permissions.
All rights granted under this License are granted for the term of
copyright on the Program, and are irrevocable provided the stated
conditions are met. This License explicitly affirms your unlimited
permission to run the unmodified Program. The output from running a
covered work is covered by this License only if the output, given its
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rights of fair use or other equivalent, as provided by copyright law.
You may make, run and propagate covered works that you do not
convey, without conditions so long as your license otherwise remains
in force. You may convey covered works to others for the sole purpose
of having them make modifications exclusively for you, or provide you
with facilities for running those works, provided that you comply with
the terms of this License in conveying all material for which you do
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for you must do so exclusively on your behalf, under your direction
and control, on terms that prohibit them from making any copies of
your copyrighted material outside their relationship with you.
Conveying under any other circumstances is permitted solely under
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makes it unnecessary.
3. Protecting Users' Legal Rights From Anti-Circumvention Law.
No covered work shall be deemed part of an effective technological
measure under any applicable law fulfilling obligations under article
11 of the WIPO copyright treaty adopted on 20 December 1996, or
similar laws prohibiting or restricting circumvention of such
measures.
When you convey a covered work, you waive any legal power to forbid
circumvention of technological measures to the extent such circumvention
is effected by exercising rights under this License with respect to
the covered work, and you disclaim any intention to limit operation or
modification of the work as a means of enforcing, against the work's
users, your or third parties' legal rights to forbid circumvention of
technological measures.
4. Conveying Verbatim Copies.
You may convey verbatim copies of the Program's source code as you
receive it, in any medium, provided that you conspicuously and
appropriately publish on each copy an appropriate copyright notice;
keep intact all notices stating that this License and any
non-permissive terms added in accord with section 7 apply to the code;
keep intact all notices of the absence of any warranty; and give all
recipients a copy of this License along with the Program.
You may charge any price or no price for each copy that you convey,
and you may offer support or warranty protection for a fee.
5. Conveying Modified Source Versions.
You may convey a work based on the Program, or the modifications to
produce it from the Program, in the form of source code under the
terms of section 4, provided that you also meet all of these conditions:
a) The work must carry prominent notices stating that you modified
it, and giving a relevant date.
b) The work must carry prominent notices stating that it is
released under this License and any conditions added under section
7. This requirement modifies the requirement in section 4 to
"keep intact all notices".
c) You must license the entire work, as a whole, under this
License to anyone who comes into possession of a copy. This
License will therefore apply, along with any applicable section 7
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regardless of how they are packaged. This License gives no
permission to license the work in any other way, but it does not
invalidate such permission if you have separately received it.
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work need not make them do so.
A compilation of a covered work with other separate and independent
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and which are not combined with it such as to form a larger program,
in or on a volume of a storage or distribution medium, is called an
"aggregate" if the compilation and its resulting copyright are not
used to limit the access or legal rights of the compilation's users
beyond what the individual works permit. Inclusion of a covered work
in an aggregate does not cause this License to apply to the other
parts of the aggregate.
6. Conveying Non-Source Forms.
You may convey a covered work in object code form under the terms
of sections 4 and 5, provided that you also convey the
machine-readable Corresponding Source under the terms of this License,
in one of these ways:
a) Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by the
Corresponding Source fixed on a durable physical medium
customarily used for software interchange.
b) Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by a
written offer, valid for at least three years and valid for as
long as you offer spare parts or customer support for that product
model, to give anyone who possesses the object code either (1) a
copy of the Corresponding Source for all the software in the
product that is covered by this License, on a durable physical
medium customarily used for software interchange, for a price no
more than your reasonable cost of physically performing this
conveying of source, or (2) access to copy the
Corresponding Source from a network server at no charge.
c) Convey individual copies of the object code with a copy of the
written offer to provide the Corresponding Source. This
alternative is allowed only occasionally and noncommercially, and
only if you received the object code with such an offer, in accord
with subsection 6b.
d) Convey the object code by offering access from a designated
place (gratis or for a charge), and offer equivalent access to the
Corresponding Source in the same way through the same place at no
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Corresponding Source along with the object code. If the place to
copy the object code is a network server, the Corresponding Source
may be on a different server (operated by you or a third party)
that supports equivalent copying facilities, provided you maintain
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available for as long as needed to satisfy these requirements.
e) Convey the object code using peer-to-peer transmission, provided
you inform other peers where the object code and Corresponding
Source of the work are being offered to the general public at no
charge under subsection 6d.
A separable portion of the object code, whose source code is excluded
from the Corresponding Source as a System Library, need not be
included in conveying the object code work.
A "User Product" is either (1) a "consumer product", which means any
tangible personal property which is normally used for personal, family,
or household purposes, or (2) anything designed or sold for incorporation
into a dwelling. In determining whether a product is a consumer product,
doubtful cases shall be resolved in favor of coverage. For a particular
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typical or common use of that class of product, regardless of the status
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actually uses, or expects or is expected to use, the product. A product
is a consumer product regardless of whether the product has substantial
commercial, industrial or non-consumer uses, unless such uses represent
the only significant mode of use of the product.
"Installation Information" for a User Product means any methods,
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and execute modified versions of a covered work in that User Product from
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code is in no case prevented or interfered with solely because
modification has been made.
If you convey an object code work under this section in, or with, or
specifically for use in, a User Product, and the conveying occurs as
part of a transaction in which the right of possession and use of the
User Product is transferred to the recipient in perpetuity or for a
fixed term (regardless of how the transaction is characterized), the
Corresponding Source conveyed under this section must be accompanied
by the Installation Information. But this requirement does not apply
if neither you nor any third party retains the ability to install
modified object code on the User Product (for example, the work has
been installed in ROM).
The requirement to provide Installation Information does not include a
requirement to continue to provide support service, warranty, or updates
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the User Product in which it has been modified or installed. Access to a
network may be denied when the modification itself materially and
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protocols for communication across the network.
Corresponding Source conveyed, and Installation Information provided,
in accord with this section must be in a format that is publicly
documented (and with an implementation available to the public in
source code form), and must require no special password or key for
unpacking, reading or copying.
7. Additional Terms.
"Additional permissions" are terms that supplement the terms of this
License by making exceptions from one or more of its conditions.
Additional permissions that are applicable to the entire Program shall
be treated as though they were included in this License, to the extent
that they are valid under applicable law. If additional permissions
apply only to part of the Program, that part may be used separately
under those permissions, but the entire Program remains governed by
this License without regard to the additional permissions.
When you convey a copy of a covered work, you may at your option
remove any additional permissions from that copy, or from any part of
it. (Additional permissions may be written to require their own
removal in certain cases when you modify the work.) You may place
additional permissions on material, added by you to a covered work,
for which you have or can give appropriate copyright permission.
Notwithstanding any other provision of this License, for material you
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that material) supplement the terms of this License with terms:
a) Disclaiming warranty or limiting liability differently from the
terms of sections 15 and 16 of this License; or
b) Requiring preservation of specified reasonable legal notices or
author attributions in that material or in the Appropriate Legal
Notices displayed by works containing it; or
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it) with contractual assumptions of liability to the recipient, for
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those licensors and authors.
All other non-permissive additional terms are considered "further
restrictions" within the meaning of section 10. If the Program as you
received it, or any part of it, contains a notice stating that it is
governed by this License along with a term that is a further
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a further restriction but permits relicensing or conveying under this
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of that license document, provided that the further restriction does
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If you add terms to a covered work in accord with this section, you
must place, in the relevant source files, a statement of the
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where to find the applicable terms.
Additional terms, permissive or non-permissive, may be stated in the
form of a separately written license, or stated as exceptions;
the above requirements apply either way.
8. Termination.
You may not propagate or modify a covered work except as expressly
provided under this License. Any attempt otherwise to propagate or
modify it is void, and will automatically terminate your rights under
this License (including any patent licenses granted under the third
paragraph of section 11).
However, if you cease all violation of this License, then your
license from a particular copyright holder is reinstated (a)
provisionally, unless and until the copyright holder explicitly and
finally terminates your license, and (b) permanently, if the copyright
holder fails to notify you of the violation by some reasonable means
prior to 60 days after the cessation.
Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.
Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License. If your rights have been terminated and not permanently
reinstated, you do not qualify to receive new licenses for the same
material under section 10.
9. Acceptance Not Required for Having Copies.
You are not required to accept this License in order to receive or
run a copy of the Program. Ancillary propagation of a covered work
occurring solely as a consequence of using peer-to-peer transmission
to receive a copy likewise does not require acceptance. However,
nothing other than this License grants you permission to propagate or
modify any covered work. These actions infringe copyright if you do
not accept this License. Therefore, by modifying or propagating a
covered work, you indicate your acceptance of this License to do so.
10. Automatic Licensing of Downstream Recipients.
Each time you convey a covered work, the recipient automatically
receives a license from the original licensors, to run, modify and
propagate that work, subject to this License. You are not responsible
for enforcing compliance by third parties with this License.
An "entity transaction" is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
organization, or merging organizations. If propagation of a covered
work results from an entity transaction, each party to that
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give under the previous paragraph, plus a right to possession of the
Corresponding Source of the work from the predecessor in interest, if
the predecessor has it or can get it with reasonable efforts.
You may not impose any further restrictions on the exercise of the
rights granted or affirmed under this License. For example, you may
not impose a license fee, royalty, or other charge for exercise of
rights granted under this License, and you may not initiate litigation
(including a cross-claim or counterclaim in a lawsuit) alleging that
any patent claim is infringed by making, using, selling, offering for
sale, or importing the Program or any portion of it.
11. Patents.
A "contributor" is a copyright holder who authorizes use under this
License of the Program or a work on which the Program is based. The
work thus licensed is called the contributor's "contributor version".
A contributor's "essential patent claims" are all patent claims
owned or controlled by the contributor, whether already acquired or
hereafter acquired, that would be infringed by some manner, permitted
by this License, of making, using, or selling its contributor version,
but do not include claims that would be infringed only as a
consequence of further modification of the contributor version. For
purposes of this definition, "control" includes the right to grant
patent sublicenses in a manner consistent with the requirements of
this License.
Each contributor grants you a non-exclusive, worldwide, royalty-free
patent license under the contributor's essential patent claims, to
make, use, sell, offer for sale, import and otherwise run, modify and
propagate the contents of its contributor version.
In the following three paragraphs, a "patent license" is any express
agreement or commitment, however denominated, not to enforce a patent
(such as an express permission to practice a patent or covenant not to
sue for patent infringement). To "grant" such a patent license to a
party means to make such an agreement or commitment not to enforce a
patent against the party.
If you convey a covered work, knowingly relying on a patent license,
and the Corresponding Source of the work is not available for anyone
to copy, free of charge and under the terms of this License, through a
publicly available network server or other readily accessible means,
then you must either (1) cause the Corresponding Source to be so
available, or (2) arrange to deprive yourself of the benefit of the
patent license for this particular work, or (3) arrange, in a manner
consistent with the requirements of this License, to extend the patent
license to downstream recipients. "Knowingly relying" means you have
actual knowledge that, but for the patent license, your conveying the
covered work in a country, or your recipient's use of the covered work
in a country, would infringe one or more identifiable patents in that
country that you have reason to believe are valid.
If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of, a
covered work, and grant a patent license to some of the parties
receiving the covered work authorizing them to use, propagate, modify
or convey a specific copy of the covered work, then the patent license
you grant is automatically extended to all recipients of the covered
work and works based on it.
A patent license is "discriminatory" if it does not include within
the scope of its coverage, prohibits the exercise of, or is
conditioned on the non-exercise of one or more of the rights that are
specifically granted under this License. You may not convey a covered
work if you are a party to an arrangement with a third party that is
in the business of distributing software, under which you make payment
to the third party based on the extent of your activity of conveying
the work, and under which the third party grants, to any of the
parties who would receive the covered work from you, a discriminatory
patent license (a) in connection with copies of the covered work
conveyed by you (or copies made from those copies), or (b) primarily
for and in connection with specific products or compilations that
contain the covered work, unless you entered into that arrangement,
or that patent license was granted, prior to 28 March 2007.
Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.
12. No Surrender of Others' Freedom.
If conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License. If you cannot convey a
covered work so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you may
not convey it at all. For example, if you agree to terms that obligate you
to collect a royalty for further conveying from those to whom you convey
the Program, the only way you could satisfy both those terms and this
License would be to refrain entirely from conveying the Program.
13. Remote Network Interaction; Use with the GNU General Public License.
Notwithstanding any other provision of this License, if you modify the
Program, your modified version must prominently offer all users
interacting with it remotely through a computer network (if your version
supports such interaction) an opportunity to receive the Corresponding
Source of your version by providing access to the Corresponding Source
from a network server at no charge, through some standard or customary
means of facilitating copying of software. This Corresponding Source
shall include the Corresponding Source for any work covered by version 3
of the GNU General Public License that is incorporated pursuant to the
following paragraph.
Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU General Public License into a single
combined work, and to convey the resulting work. The terms of this
License will continue to apply to the part which is the covered work,
but the work with which it is combined will remain governed by version
3 of the GNU General Public License.
14. Revised Versions of this License.
The Free Software Foundation may publish revised and/or new versions of
the GNU Affero General Public License from time to time. Such new versions
will be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.
Each version is given a distinguishing version number. If the
Program specifies that a certain numbered version of the GNU Affero General
Public License "or any later version" applies to it, you have the
option of following the terms and conditions either of that numbered
version or of any later version published by the Free Software
Foundation. If the Program does not specify a version number of the
GNU Affero General Public License, you may choose any version ever published
by the Free Software Foundation.
If the Program specifies that a proxy can decide which future
versions of the GNU Affero General Public License can be used, that proxy's
public statement of acceptance of a version permanently authorizes you
to choose that version for the Program.
Later license versions may give you additional or different
permissions. However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.
15. Disclaimer of Warranty.
THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
16. Limitation of Liability.
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.
17. Interpretation of Sections 15 and 16.
If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
<one line to give the program's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
Also add information on how to contact you by electronic and paper mail.
If your software can interact with users remotely through a computer
network, you should also make sure that it provides a way for users to
get its source. For example, if your program is a web application, its
interface could display a "Source" link that leads users to an archive
of the code. There are many ways you could offer source, and different
solutions will be better for different programs; see section 13 for the
specific requirements.
You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU AGPL, see
<https://www.gnu.org/licenses/>.
+96
View File
@@ -0,0 +1,96 @@
CC = clang
CXX = clang++
GIT_HASH ?= $(shell [ -d .git ] && git rev-parse HEAD)
CPPFLAGS = -g -Imimalloc/include -pthread -std=c++20 \
-Wno-deprecated-volatile \
-DMOLD_VERSION=\"0.9.2\" \
-DGIT_HASH=\"$(GIT_HASH)\" \
$(EXTRA_CPPFLAGS)
LDFLAGS += $(EXTRA_LDFLAGS)
LIBS = -Wl,-as-needed -lcrypto -pthread -ltbb -lz -lxxhash -ldl
OBJS = main.o object_file.o input_sections.o output_chunks.o \
mapfile.o perf.o linker_script.o archive_file.o output_file.o \
subprocess.o gc_sections.o icf.o symbols.o cmdline.o filepath.o \
passes.o tar.o compress.o memory_mapped_file.o relocatable.o \
arch_x86_64.o arch_i386.o
PREFIX ?= /usr
DEBUG ?= 0
LTO ?= 0
ASAN ?= 0
TSAN ?= 0
ifeq ($(DEBUG), 1)
CPPFLAGS += -O0
else
CPPFLAGS += -O2
endif
ifeq ($(LTO), 1)
CPPFLAGS += -flto -O3
LDFLAGS += -flto
endif
ifeq ($(ASAN), 1)
CPPFLAGS += -fsanitize=address
LDFLAGS += -fsanitize=address
else
# By default, we want to use mimalloc as a memory allocator.
# Since replacing the standard malloc is not compatible with ASAN,
# we do that only when ASAN is not enabled.
ifdef SYSTEM_MIMALLOC
LIBS += -lmimalloc
else
MIMALLOC_LIB = mimalloc/out/release/libmimalloc.a
LIBS += -Wl,-whole-archive $(MIMALLOC_LIB) -Wl,-no-whole-archive
endif
endif
ifeq ($(TSAN), 1)
CPPFLAGS += -fsanitize=thread
LDFLAGS += -fsanitize=thread
endif
all: mold mold-wrapper.so
mold: $(OBJS) $(MIMALLOC_LIB)
$(CXX) $(CXXFLAGS) $(OBJS) -o $@ $(LDFLAGS) $(LIBS)
mold-wrapper.so: mold-wrapper.c Makefile
$(CC) -fPIC -shared -o $@ $< -ldl
$(OBJS): mold.h elf.h Makefile
$(MIMALLOC_LIB):
mkdir -p mimalloc/out/release
(cd mimalloc/out/release; CFLAGS=-DMI_USE_ENVIRON=0 cmake ../..)
$(MAKE) -C mimalloc/out/release
test tests check: all
$(MAKE) -C test --output-sync --no-print-directory
install: all
install -m 755 -d $(DESTDIR)$(PREFIX)/bin
install -m 755 mold $(DESTDIR)$(PREFIX)/bin
strip $(DESTDIR)$(PREFIX)/bin/mold
install -m 755 -d $(DESTDIR)$(PREFIX)/lib/mold
install -m 644 mold-wrapper.so $(DESTDIR)$(PREFIX)/lib/mold
strip $(DESTDIR)$(PREFIX)/lib/mold/mold-wrapper.so
install -m 755 -d $(DESTDIR)$(PREFIX)/share/man/man1
install -m 644 docs/mold.1 $(DESTDIR)$(PREFIX)/share/man/man1
rm -f $(DESTDIR)$(PREFIX)/share/man/man1/mold.1.gz
gzip -9 $(DESTDIR)$(PREFIX)/share/man/man1/mold.1
uninstall:
rm -f $(DESTDIR)$(PREFIX)/bin/mold
rm -f $(DESTDIR)$(PREFIX)/share/man/man1/mold.1.gz
rm -rf $(DESTDIR)$(PREFIX)/lib/mold
clean:
rm -rf *.o *~ mold mold-wrapper.so test/tmp
.PHONY: all test tests check clean $(TESTS)
+562 -216
View File
@@ -1,205 +1,115 @@
# mold: A Modern Linker
mold is a faster drop-in replacement for existing Unix linkers. It is several
times quicker than the LLVM lld linker, the second-fastest open-source linker,
which I initially developed a few years ago. mold aims to enhance developer
productivity by minimizing build time, particularly in rapid
debug-edit-rebuild cycles.
![mold image](docs/mold.jpg)
Here is a performance comparison of GNU ld, GNU gold, LLVM lld, and
mold when linking final debuginfo-enabled executables for major large
programs on a simulated 16-core, 32-thread machine.
mold is a high performance drop-in replacement for existing Unix
linkers. It is several times faster than LLVM lld linker, the (then-)
fastest open-source linker which I originally created a few years ago.
Here is a performance comparison of GNU gold, LLVM lld and mold for
linking final executables of major large programs.
![Link speed comparison](docs/chart.svg)
| Program (linker output size) | GNU gold | LLVM lld | mold | mold w/ preloading
|-------------------------------|----------|----------|-------|-------------------
| Firefox 87 (1.6 GiB) | 29.2s | 6.16s | 1.69s | 0.79s
| Chrome 86 (1.9 GiB) | 54.5s | 11.7s | 1.85s | 0.97s
| Clang 13 (3.1 GiB) | 59.4s | 5.68s | 2.76s | 0.86s
| Program (linker output size) | GNU ld | GNU gold | LLVM lld | mold
|-------------------------------|--------|----------|----------|------
| MySQL 8.3 (0.47 GiB) | 10.84s | 7.47s | 1.64s | 0.46s
| Clang 19 (1.56 GiB) | 42.07s | 33.13s | 5.20s | 1.35s
| Chromium 124 (1.35 GiB) | N/A | 27.40s | 6.10s | 1.52s
(These nubmers are measured on an AMD Threadripper 3990X 64-core
machine with 32 threads enabled. All programs are built with debug
info enabled.)
mold is so fast that it is only 2x _slower_ than the `cp` command on the same
machine. If you find that mold is not faster than other linkers, feel
free to [file a bug report](https://github.com/rui314/mold/issues).
Let me explain the "w/ preloading" column. mold supports the file
preloading feature. That is, if you run mold with `-preload` flag
along with other command line flags, it becomes a daemon and halts
after parsing input files. Then, if you invoke mold with the same
command line options (except `-preload` flag), it tells the daemon to
reload only updated files and proceed. With this feature enabled, and
if most of the input files haven't been updated, mold achieve a
near-`cp` performance or even exceeds it, as the throughput of file
copy using the `cp` command is about 2 GiB/s on my machine.
mold supports x86-64, i386, ARM64, ARM32, 64-bit/32-bit little/big-endian
RISC-V, 32-bit PowerPC, 64-bit big-endian PowerPC ELFv1, 64-bit little-endian
PowerPC ELFv2, s390x, 64-bit/32-bit LoongArch, SPARC64, m68k, and SH-4.
So, mold is extremely fast per-se and even faster with a bit of cheating.
## Why does linking speed matter?
Why is mold so fast? One reason is because it simply uses faster
algorithms and efficient data structures than other linkers do.
The other reason is that the new linker is highly parallelized.
If you are using a compiled language such as C, C++, or Rust, a build consists
of two phases. In the first phase, a compiler compiles source files into
object files (`.o` files). In the second phase, a linker takes all object
files and combines them into a single executable or shared library file.
Here is a side-by-side comparison of per-core CPU usage of lld (left)
and mold (right). They are linking the same program, Chromium
executable.
The second phase can be time-consuming if your build output is large. mold can
speed up this process, saving you time and preventing distractions while
waiting for a lengthy build to finish. The difference is most noticeable
during rapid debug-edit-rebuild cycles.
![](docs/htop.gif)
## Installation
As you can see, mold uses all available cores throughout its execution
and finishes quickly. On the other hand, lld failed to use available
cores most of the time. On this demo, the maximum parallelism is
artificially capped to 16 so that the bars fit in the GIF.
Binary packages for the following systems are currently available:
Currently, mold is being developed with Linux/x86-64 as the primary
target platform. mold can link many user-land programs including large
ones such as web browsers for that target. It also has preliminary
Linux/i386 support. Supporting other OSes and ISAs are planned after
Linux/x86-64 support is complete.
[![Packaging status](https://repology.org/badge/vertical-allrepos/mold.svg)](https://repology.org/project/mold/versions)
## How to build
## How to Build
mold is written in C++20, so you need a very recent version of GCC or
Clang. I'm using Ubuntu 20.04 as a development platform. In that
environment, you can build mold by the following commands.
mold is written in C++20, so if you build mold yourself, you will need a
recent version of a C++ compiler and a C++ standard library. We recommend GCC
10.2 or Clang 16.0.0 (or later) and libstdc++ 10 or libc++ 7 (or later).
### Install Dependencies
To install build dependencies, run `./install-build-deps.sh` in this
directory. It will detect your Linux distribution and attempt to install the
necessary packages. You may need to run it as root.
### Compile mold
```shell
git clone --branch stable https://github.com/rui314/mold.git
cd mold
./install-build-deps.sh
cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_COMPILER=c++ -B build
cmake --build build -j$(nproc)
sudo cmake --build build --target install
```
$ sudo apt-get install build-essential libstdc++-10-dev cmake clang libssl-dev zlib1g-dev libxxhash-dev libtbb-dev git
$ git clone https://github.com/rui314/mold.git
$ cd mold
$ make
```
You might need to pass a C++20 compiler command name to `cmake`. In the
example above, `c++` is passed. If that doesn't work for you, try a specific
version of a compiler, such as `g++-10` or `clang++-12`.
The last `make` command creates `mold` executable.
By default, `mold` is installed to `/usr/local/bin`. You can change the
installation location by passing `-DCMAKE_INSTALL_PREFIX=<directory>`.
For other cmake options, see the comments in `CMakeLists.txt`.
If you don't have Ubuntu 20.04, or if for any reason `make` in the
above commands doesn't work for you, you can use Docker to build it in
a Docker environment. To do so, just run `./build-static.sh` in this
directory. The script creates a Ubuntu 20.04 Docker image, install
necessary tools and libraries to it and build mold as a static binary.
If you are not using a recent enough Linux distribution, or if `cmake` does
not work for you for any reason, you can use Podman to build mold in a
container. To do so, run `./dist.sh` in this directory instead of using
`cmake`. The shell script will pull a container image, build mold and auxiliary
files inside it, and package them into a single tar file named
`dist/mold-$version-$arch-linux.tar.gz`. You can extract the tar file anywhere
and use the mold executable in it.
`make test` depends on a few more packages. To install, run the following commands:
```
$ sudo dpkg --add-architecture i386
$ sudo apt-get install dwarfdump libc6-dev:i386 lib32gcc-10-dev gcc-multilib
```
## How to use
<details><summary>A classic way to use mold</summary>
On Unix, the linker command (which is usually `/usr/bin/ld`) is
invoked indirectly by `cc` (or `gcc` or `clang`), which is typically
in turn indirectly invoked by `make` or some other build system
command. It is sometimes very hard to pass an appropriate command line
option to `cc` to specify an alternative linker.
On Unix, the linker command (usually `/usr/bin/ld`) is indirectly invoked by
the compiler driver (typically `cc`, `gcc`, or `clang`), which is in turn
indirectly invoked by `make` or other build system commands.
To deal with the situation, mold has a feature to intercept all
invocations of `/usr/bin/ld`, `/usr/bin/ld.lld` or `/usr/bin/ld.gold`
and redirect it to itself. To use the feature, run `make` (or other
build command) as a subcommand of mold as follows:
If you can specify an additional command line option for your compiler driver
by modifying the build system's config files, add one of the following flags
to use mold instead of `/usr/bin/ld`:
- For Clang: pass `-fuse-ld=mold`
- For GCC 12.1.0 or later: pass `-fuse-ld=mold`
- For GCC before 12.1.0: the `-fuse-ld` option does not accept `mold` as a
valid argument, so you need to use the `-B` option instead. The `-B` option
tells GCC where to look for external commands like `ld`.
If you have installed mold with `make install`, there should be a directory
named `/usr/libexec/mold` (or `/usr/local/libexec/mold`, depending on your
`$PREFIX`), and the `ld` command should be there. The `ld` is actually a
symlink to `mold`. So, all you need is to pass `-B/usr/libexec/mold` (or
`-B/usr/local/libexec/mold`) to GCC.
If you haven't installed `ld.mold` to any `$PATH`, you can still pass
`-fuse-ld=/absolute/path/to/mold` to clang to use mold. However, GCC does not
accept an absolute path as an argument for `-fuse-ld`.
</details>
<details><summary>If you are using Rust</summary>
Create `.cargo/config.toml` in your project directory with the following:
```toml
[target.'cfg(target_os = "linux")']
linker = "clang"
rustflags = ["-C", "link-arg=-fuse-ld=/path/to/mold"]
```
$ path/to/mold -run make <make-options-if-any>
```
where `/path/to/mold` is an absolute path to the mold executable. In the
example above, we use `clang` as a linker driver since it always accepts the
`-fuse-ld` option. If your GCC is recent enough to recognize the option, you
may be able to remove the `linker = "clang"` line.
Internally, mold invokes a given command with `LD_PRELOAD` environment
variable set to its companion shared object file. The shared object
file intercepts all function calls to exec-family functions to replace
`argv[0]` with `mold` if it is `/usr/bin/ld`, `/usr/bin/ld.gold` or
`/usr/bin/ld.lld`.
```toml
[target.'cfg(target_os = "linux")']
rustflags = ["-C", "link-arg=-fuse-ld=mold"]
```
Alternatively, you can pass `-fuse-ld=<absolute-path-to-mold-executable>`
to a linker command line. Since GCC doesn't support that option,
I recommend using clang.
If you want to use mold for all projects, add the above snippet to
`~/.cargo/config.toml`.
</details>
<details><summary>If you are using Nim</summary>
Create `config.nims` in your project directory with the following:
```nim
when findExe("mold").len > 0 and defined(linux):
switch("passL", "-fuse-ld=mold")
```
where `mold` must be included in the `PATH` environment variable. In this
example, `gcc` is used as the linker driver. Use the `-fuse-ld` option if your
GCC is recent enough to recognize this option.
If you want to use mold for all projects, add the above snippet to
`~/.config/config.nims`.
</details>
<details><summary>If you are using Conan package manager</summary>
You can configure [Conan](https://github.com/conan-io) to download the latest
version of `mold` and use it as the linker when building your dependencies and
projects from source. Please see the instructions [here](https://conan.io/center/recipes/mold).
</details>
<details><summary>mold -run</summary>
It is sometimes very hard to pass an appropriate command line option to `cc`
to specify an alternative linker. To address this situation, mold has a
feature to intercept all invocations of `ld`, `ld.bfd`, `ld.lld`, or `ld.gold`
and redirect them to itself. To use this feature, run `make` (or another build
command) as a subcommand of mold as follows:
```shell
mold -run make <make-options-if-any>
```
Internally, mold invokes a given command with the `LD_PRELOAD` environment
variable set to its companion shared object file. The shared object file
intercepts all function calls to `exec(3)`-family functions to replace
`argv[0]` with `mold` if it is `ld`, `ld.bf`, `ld.gold`, or `ld.lld`.
</details>
<details><summary>GitHub Actions</summary>
You can use our [setup-mold](https://github.com/rui314/setup-mold) GitHub
Action to speed up GitHub-hosted continuous builds. Although GitHub Actions
run on a 4 core machine, mold is still significantly faster than the default
GNU linker, especially when linking large programs.
</details>
<details><summary>Verify that you are using mold</summary>
mold leaves its identification string in the `.comment` section of an output
mold leaves its identification string in `.comment` section in an output
file. You can print it out to verify that you are actually using mold.
```shell
```
$ readelf -p .comment <executable-file>
String dump of section '.comment':
@@ -207,69 +117,505 @@ String dump of section '.comment':
[ 2b] mold 9a1679b47d9b22012ec7dfbda97c8983956716f7
```
If `mold` is present in the `.comment` section, the file was created by mold.
If `mold` is in `.comment`, the file is created by mold.
</details>
# Design and implementation of mold
<details><summary>Online manual</summary>
For the rest of this documentation, I'll explain the design and the
implementation of mold. If you are only interested in using mold, you
don't need to read the below.
Since mold is a drop-in replacement, you should be able to use it without
reading its manual. However, if you need it, [mold's man page](docs/mold.md)
is available online. You can read the same manual by running `man mold`.
## Motivation
</details>
Here is why I'm writing a new linker:
## Why is mold so fast?
- Even though lld has significantly improved the situation, linking is
still one of the slowest steps in a build. It is especially
annoying when I changed one line of code and had to wait for a few
seconds or even more for a linker to complete. It should be
instantaneous. There's a need for a faster linker.
One reason is that it utilizes faster algorithms and more efficient data
structures compared to other linkers. Another reason is that mold is highly
parallelized.
- The number of cores on a PC has increased a lot lately, and this
trend is expected to continue. However, the existing linkers can't
take the advantage of the trend because they don't scale well for more
cores. I have a 64-core/128-thread machine, so my goal is to create
a linker that uses the CPU nicely. mold should be much faster than
other linkers on 4 or 8-core machines too, though.
Here is a side-by-side comparison of per-core CPU usage for lld (left) and
mold (right), linking the same program, a Chromium executable.
- It looks to me that the designs of the existing linkers are somewhat
too similar, and I believe there are a lot of drastically different
designs that haven't been explored yet. Developers generally don't
care about linkers as long as they work correctly, and they don't
even think about creating a new one. So there may be lots of low
hanging fruits there in this area.
![CPU usage comparison in htop animation](docs/htop.gif)
## Basic design
As you can see, mold uses all available cores throughout its execution and
finishes quickly. In contrast, lld fails to utilize available cores most of
the time. In this demo, the maximum parallelism is artificially capped at 16,
so that the bars fit in the GIF.
- In order to achieve a `cp`-like performance, the most important
thing is to fix the layout of an output file as quickly as possible, so
that we can start copying actual data from input object files to an
output file as soon as possible.
For details, please see the [design notes](docs/design.md).
- Copying data from input files to an output file is I/O-bounded, so
there should be room for doing computationally-intensive tasks while
copying data from one file to another.
## Sponsors
- We should allow the linker to preload object files from disk and
parse them in memory before a complete set of input object files
is ready. To do so, we need
to split the linker into two in such a way that the latter half of
the process finishes as quickly as possible by speculatively parsing
and preprocessing input files in the first half of the process.
It is taken for granted nowadays that compiler toolchains can be easily
installed and used for free, and people may not think too much about the
individuals behind these "free tools". mold supports many projects, but it
is essentially a one-person project. This situation is similar to the one
depicted in the following xkcd illustration.
- One of the most computationally-intensive stage among linker stages
is symbol resolution. To resolve symbols, we basically have to throw
all symbol strings into a hash table to match undefined symbols with
defined symbols. But this can be done in the preloading stage using
[string interning](https://en.wikipedia.org/wiki/String_interning).
[![xkcd 2347](https://imgs.xkcd.com/comics/dependency.png)](https://xkcd.com/2347)
- Object files may contain a special section called a mergeable string
section. The section contains lots of null-terminated strings, and
the linker is expected to gather all mergeable string sections and
merge their contents. So, if two object files contain the same
string literal, for example, the resulting output will contain a
single merged string. This step is computationally-intensive, but string
merging can be done in the preloading stage using string interning.
If you think that the "Nebraska guy" should be rewarded, please consider
becoming our [GitHub sponsor](https://github.com/sponsors/rui314)!
- Static archives (.a files) contain object files, but the static
archive's string table contains only defined symbols of member
object files and lacks other types of symbols. That makes static
archives unsuitable for speculative parsing. Therefore, the linker
should ignore the symbol table of static archive and directly read
static archive members.
We thank everyone who sponsors our project. In particular, we'd like to acknowledge
the following people and organizations who have sponsored $128/month or more:
- If there's a relocation that uses a GOT of a symbol, then we have to
create a GOT entry for that symbol. Otherwise, we shouldn't. That
means we need to scan all relocation tables to fix the length and
the contents of a .got section. This is computationally intensive,
but this step is parallelizable.
### Corporate sponsors
## Compatibility
<a href="https://mercury.com"><img src="docs/mercury-logo.png" align=center height=120 width=400 alt=Mercury></a>
- GNU ld, GNU gold and LLVM lld support essentially the same set of
command line options and features. mold doesn't have to be
completely compatible with them. As long as it can be used for
linking large user-land programs, I'm fine with that. It is OK to
leave some command line options unimplemented; if mold is blazingly
fast, other projects would still be happy to adopt it by modifying
their projects' build files.
<a href="https://cybozu-global.com"><img src="docs/cyboze-logo.png" align=center height=120 width=133 alt=Cybozu></a>
- mold emits Linux executables and runs only on Linux. I won't avoid
Unix-ism when writing code. I don't want to think about portability
until mold becomes a thing that's worth to be ported.
<a href="https://www.emergetools.com"><img src="docs/emerge-tools-logo.png" align=center height=120 width=240 alt="Emerge Tools"></a><br>
## Linker Script
- [G-Research](https://www.gresearch.co.uk)
- [Signal Slot Inc.](https://github.com/signal-slot)
- [GlareDB](https://github.com/GlareDB)
Linker script is an embedded language for the linker. It is mainly
used to control how input sections are mapped to output sections and
the layout of the output, but it can also do a lot of tricky stuff.
Its feature is useful especially for embedded programming, but it's
also an awfully underdocumented and complex language.
### Individual sponsors
We have to implement a subset of the linker script language anwyay,
because on Linux, /usr/lib/x86_64-linux-gnu/libc.so is (despite its
name) not a shared object file but actually an ASCII file containing
linker script code to load the _actual_ libc.so file. But the feature
set for this purpose is very limited, and it is okay to implement them
to mold.
- [Wei Wu](https://github.com/lazyparser)
- [kyle-elliott](https://github.com/kyle-elliott)
- [Bryant Biggs](https://github.com/bryantbiggs)
- [kraptor23](https://github.com/kraptor23)
- [Jinkyu Yi](https://github.com/jincreator)
- [Pedro Navarro](https://github.com/pedronavf)
Besides that, we really don't want to implement the linker script
langauge. But at the same time, we want to satisfy the user needs that
are currently satisfied with the linker script langauge. So, what
should we do? Here is my observation:
- Linker script allows to do a lot of tricky stuff, such as specifying
the exact layout of a file, inserting arbitrary bytes between
sections, etc. But most of them can be done with a post-link binary
editing tool (such as `objcopy`).
- It looks like there are two things that truely cannot be done by a
post-link editing tool: (a) mapping input sections to output
sections, and (b) applying relocations.
From the above observation, I believe we need to provide only the
following features instead of the entire linker script langauge:
- A method to specify how input sections are mapped to output
sections, and
- a method to set addresses to output sections, so that relocations
are applied based on desired adddresses.
I believe everything else can be done with a post-link binary editing
tool.
## Details
- As we aim to the 1 second goal for Chromium, every millisecond
counts. We can't ignore the latency of process exit. If we mmap a
lot of files, \_exit(2) is not instantaneous but takes a few hundred
milliseconds because the kernel has to clean up a lot of
resources. As a workaround, we should organize the linker command as
two processes; the first process forks the second process, and the
second process does the actual work. As soon as the second process
writes a result file to a filesystem, it notifies the first process,
and the first process exits. The second process can take time to
exit, because it is not an interactive process.
- At least on Linux, it looks like the filesystem's performance to
allocate new blocks to a new file is the limiting factor when
creating a new large file and filling its contents using mmap.
If you already have a large file in the buffer cache, writing to it is
much faster than creating a new fresh file and writing to it.
Based on this observation, mold overwrites to an existing
executable file if exists. My quick benchmark showed that I could
save 300 milliseconds when creating a 2 GiB output file.
Linux doesn't allow to open an executable for writing if it is
running (you'll get "text busy" error if you attempt). mold
falls back to the usual way if it fails to open an output file.
- The output from the linker should be deterministic for the sake of
[build reproducibility](https://en.wikipedia.org/wiki/Reproducible_builds)
and ease of debugging. This might add a little bit of overhead to
the linker, but that shouldn't be too much.
- A .build-id, a unique ID embedded to an output file, is usually
computed by applying a cryptographic hash function (e.g. SHA-1) to
an output file. This is a slow step, but we can speed it up by
splitting a file into small chunks, computing SHA-1 for each chunk,
and then computing SHA-1 of the concatenated SHA-1 hashes
(i.e. constructing a [Markle
Tree](https://en.wikipedia.org/wiki/Merkle_tree) of height 2).
Modern x86 processors have purpose-built instructions for SHA-1 and
can compute SHA-1 pretty quickly at about 2 GiB/s rate. Using 16
cores, a build-id for a 2 GiB executable can be computed in 60 to 70
milliseconds.
- BFD, gold, and lld support section garbage collection. That is, a
linker runs a mark-sweep garbage collection on an input graph, where
sections are vertices and relocations are edges, to discard all
sections that are not reachable from the entry point symbol
(i.e. `_start`) or a few other root sections. In mold, we are using
multiple threads to mark sections concurrently.
- Similarly, BFD, gold an lld support Identical Comdat Folding (ICF)
as a yet another size optimization. ICF merges two or more read-only
sections that happen to have the same contents and relocations.
To do that, we have to find isomorphic subgraphs from larger graphs.
I implemented a new algorithm for mold, which is 5x faster than lld
to do ICF for Chromium (from 5 seconds to 1 second).
- [Intel Threading Building
Blocks](https://github.com/oneapi-src/oneTBB) (TBB) is a good
library for parallel execution and has several concurrent
containers. We are particularly interested in using
`parallel_for_each` and `concurrent_hash_map`.
- TBB provides `tbbmalloc` which works better for multi-threaded
applications than the glib'c malloc, but it looks like
[jemalloc](https://github.com/jemalloc/jemalloc) and
[mimalloc](https://github.com/microsoft/mimalloc) are a little bit
more scalable than `tbbmalloc`.
## Size of the problem
When linking Chrome, a linker reads 3,430,966,844 bytes of data in
total. The data contains the following items:
| Data item | Number
| ------------------------ | ------
| Object files | 30,723
| Public undefined symbols | 1,428,149
| Mergeable strings | 1,579,996
| Comdat groups | 9,914,510
| Regular sections¹ | 10,345,314
| Public defined symbols | 10,512,135
| Symbols | 23,953,607
| Sections | 27,543,225
| Relocations against SHF_ALLOC sections | 39,496,375
| Relocations | 62,024,719
¹ Sections that have to be copied from input object files to an
output file. Sections that contain relocations or symbols are for
example excluded.
## Internals
In this section, I'll explain the internals of mold linker.
### A brief history of Unix and the Unix linker
Conceptually, what a linker does is pretty simple. A compiler compiles
a fragment of a program (a single source file) into a fragment of
machine code and data (an object file, which typically has the .o
extension), and a linker stiches them together into a single
executable or a shared library image.
In reality, modern linkers for Unix-like systems are much more
compilcated than the naive understanding because they have gradually
gained one feature at a time over the 50 years history of Unix, and
they are now something like a bag of lots of miscellaneous features in
which none of the features is more important than the others. It is
very easy to miss the forest for the trees, since for those who don't
know the details of the Unix linker, it is not clear which feature is
essential and which is not.
That being said, one thing is clear that at any point of Unix history,
a Unix linker has a coherent feature set for the Unix of that age. So,
let me entangle the history to see how the operating system, runtime
and linker have gained features that we see today. That should give
you an idea why a particular feature has been added to a linker in the
first place.
1. Original Unix didn't support shared library, and a program was
always loaded to a fixed address. An executable was something like
a memory dump which was just loaded to a particular address by the
kernel. After loading, the kernel started executing the program by
setting the instruction pointer to a particular address.
The most essential feature for any linker is relocation processing.
The original Unix linker of course supported that. Let me explain
what that is.
Individual object files are inevitably incomplete as a program,
because when a compiler created them, it only see a part of an
entire program. For example, if an object file contains a function
call that refers other object file, the `call` instruction in the
object cannot be complete, as the compiler has no idea as to what
is the called function's address. To deal with this, the compiler
emits a placeholder value (typically just zero) instead of a real
address and leave a metadata in an object file saying "fix offset X
of this file with an address of Y". That metadata is called
"relocation". Relocations are typically processed by the linker.
It is easy for a linker to apply relocations for the original Unix
because a program is always loaded to a fixed address. It exactly
knows the addresses of all functions and data when linking a
program.
Static library support, which is still an important feature of Unix
linker, also dates back to this early period of Unix history.
To understand what it is, imagine that you are trying to compile
a program for the early Unix. You don't want to waste time to
compile libc functions every time you compile your program (the
computers of the era was incredibly slow), so you have already
placed each libc function into a separate source file and compiled
them individually. That means, you have object files for each libc
function, e.g., printf.o, scanf.o, atoi.o, write.o, etc.
Given this configuration, all you have to do to link your program
against libc functions is to pick up a right set of libc object
files and give them to the linker along with the object files of your
program. But, keeping the linker command line in sync with the
libc functions you are using in your program is bothersome. You can
be conservative; you can specify all libc object files to the
command line, but that leads to program bloat because the linker
unconditionally link all object files given to it no matter whether
they are used or not. So, a new feature was added to the linker to
fix the problem. That is the static library, which is also called
the archive file.
An archive file is just a bundle of object files, just like zip
file but in an uncompressed form. An achive file typically has the
.a file extension and named after its contents. For example, the
archive file containing all libc objects is named `libc.a`.
If you pass an archive file along with other object files to the
linker, the linker pulls out an object file from the archive _only
when_ it is referenced by other object files. In other words,
unlike object files directly given to a linker, object files
wrapped in an archive are not linked to an output by default.
An archive works as supplements to complete your program.
Even today, you can still find a libc archive file. Run `ar t
/usr/lib/x86_64-linux-gnu/libc.a` on Linux should give you a list
of object files in the libc archive.
2. In '80s, Sun Microsystems, a leading commercial Unix vendor at the
time, added a shared library support to their Unix variant, SunOS.
(This section is incomplete.)
## Concurrency strategy
In this section, I'll explain the high level concurrency strategy of
mold.
In most places, mold adopts data parallelism. That is, we have a huge
number of piece of data of the same kind, and we process each of them
individually using parallel for-loop. For example, after identifying
the exact set of input object files, we need to scan all relocation
tables to determine the sizes of .got and .plt sections. We do that
using a parallel for-loop. The granularity of parallel processing in
this case is the relocation table.
Data parallelism is very efficient and scalable because there's no
need for threads to communicate with each other while working on each
element of data. In addition to that, data parallelism is easy to
understand, as it is just a for-loop in which multiple iterations may
be executed in parallel. We don't use high-level communication or
synchronization mechanisms such as channels, futures, promises,
latches or something like that in mold.
In some cases, we need to share a little bit of data between threads
while executing a parallel for-loop. For example, the loop to scan
relocations turns on "requires GOT" or "requires PLT" flags in a
symbol. Symbol is a shared resource, and writing to them from multiple
threads without synchronization is unsafe. To deal with it, we made
the flag an atomic variable.
The other common pattern you can find in mold which is build on top of
the parallel for-loop is the map-reduce pattern. That is, we run a
parallel for-loop on a large data set to produce a small data set and
process the small data set with a single thread. Let me take a
build-id computation as an example. Build-id is typically computed by
applying a cryptographic hash function such as SHA-1 on a linker's
output file. To compute it, we first consider an output as a sequence
of 1 MiB blocks and compute a SHA-1 hash for each block in parallel.
Then, we concatenate the SHA-1 hashes and compute a SHA-1 hash on the
hashes to get a final build-id.
Finally, we use concurrent hashmap at a few places in mold. Concurrent
hashmap is a hashmap to which multiple threads can safely insert items
in parallel. We use it in the symbol resolution stage, for example.
To resolve symbols, we basically have to throw in all defined symbols
into a hash table, so that we can find a matching defined symbol for
an undefined symbol by name. We do the hash table insertion from a
parallel for-loop which iterates over a list of input files.
Overall, even though mold is highly scalable, it succeeded to avoid
complexties you often find in complex parallel programs. From high
level, mold just serially executes linker's internal passes one by
one. Each pass is parallelized using parallel for-loops.
## Rejected ideas
In this section, I'll explain the alternative designs I currently do
not plan to implement and why I turned them down.
- Placing variable-length sections at end of an output file and start
copying file contents before fixing the output file layout
Idea: Fixing the layout of regular sections seems easy, and if we
place them at beginning of a file, we can start copying their
contents from their input files to an output file. While copying
file contents, we can compute the sizes of variable-length sections
such as .got or .plt and place them at end of the file.
Reason for rejection: I did not choose this design because I doubt
if it could actually shorten link time and I think I don't need it
anyway.
The linker has to de-duplicate comdat sections (i.e. inline
functions that are included into multiple object files), so we
cannot compute the layout of regular sections until we resolve all
symbols and de-duplicate comdats. That takes a few hundred
milliseconds. After that, we can compute the sizes of
variable-length sections in less than 100 milliseconds. It's quite
fast, so it doesn't seem to make much sense to proceed without
fixing the final file layout.
The other reason to reject this idea is because there's good a
chance for this idea to have a negative impact on linker's overall
performance. If we copy file contents before fixing the layout, we
can't apply relocations to them while copying because symbol
addresses are not available yet. If we fix the file layout first, we
can apply relocations while copying, which is effectively zero-cost
due to a very good data locality. On the other hand, if we apply
relocations long after we copy file contents, it's pretty expensive
because section contents are very likely to have been evicted from
CPU cache.
- Incremental linking
Idea: Incremental linking is a technique to patch a previous linker's
output file so that only functions or data that are updated from the
previous build are written to it. It is expected to significantly
reduce the amount of data copied from input files to an output file
and thus speed up linking. GNU BFD and gold linkers support it.
Reason for rejection: I turned it down because it (1) is
complicated, (2) doesn't seem to speed it up that much and (3) has
several practical issues. Let me explain each of them.
First, incremental linking for real C/C++ programs is not as easy as
one might think. Let me take malloc as an example. malloc is usually
defined by libc, but you can implement it in your program, and if
that's the case, the symbol `malloc` will be resolved to your
function instead of the one in libc. If you include a library that
defines malloc (such as libjemalloc or libtbbmallc) before libc,
their malloc will override libc's malloc.
Assume that you are using a nonstandard malloc. What if you remove
your malloc from your code, or remove `-ljemalloc` from your
Makefile? The linker has to include a malloc from libc, which may
include more object files to satisfy its dependencies. Such code
change can affect the entire program rather than just replacing one
function. The same is true to adding malloc to your program. Making
a local change doesn't necessarily result in a local change in the
binary level. It can easily have cascading effects.
Some ELF fancy features make incremental linking even harder to
implement. Take the weak symbol as an example. If you define `atoi`
as a weak symbol in your program, and if you are not using `atoi`
at all in your program, that symbol will be resolved to address
0. But if you start using some libc function that indirectly calls
`atoi`, then `atoi` will be included to your program, and your weak
symbol will be resolved to that function. I don't know how to
efficiently fix up a binary for this case.
This is a hard problem, so existing linkers don't try too hard to
solve it. For example, IIRC, gold falls back to full link if any
function is removed from a previous build. If you want to not annoy
users in the fallback case, you need to make full link fast anyway.
Second, incremental linking itself has an overhead. It has to detect
updated files, patch an existing output file and write additional
data to an output file for future incremental linking. GNU gold, for
instance, takes almost 30 seconds on my machine to do a null
incremental link (i.e. no object files are updated from a previous
build) for chrome. It's just too slow.
Third, there are other practical issues in incremental linking. It's
not reproducible, so your binary isn't going to be the same as other
binaries even if you are compiling the same source tree using the
same compiler toolchain. Or, it is complex and there might be a bug
in it. If something doesn't work correctly, "remove --incremental
from your Makefile and try again" could be a piece of advise, but
that isn't ideal.
So, all in all, incremental linking is tricky. I wanted to make full
link as fast as possible, so that we don't have to think about how
to workaround the slowness of full link.
- Defining a completely new file format and use it
Idea: Sometimes, the ELF file format itself seems to be a limiting
factor of improving linker's performance. We might be able to make a
far better one if we create a new file format.
Reason for rejection: I rejected the idea because it apparently has
a practical issue (backward compatibility issue) and also doesn't
seem to improve performance of linkers that much. As clearly
demonstrated by mold, we can create a fast linker for ELF. I believe
ELF isn't that bad, after all. The semantics of the existing Unix
linkers, such as the name resolution algorithm or the linker script,
have slowed the linkers down, but that's not a problem of the file
format itself.
- Watching object files using inotify(2)
Idea: When mold is running as a daemon for preloading, use
inotify(2) to watch file system updates so that it can reload files
as soon as they are updated.
Reason for rejection: Just like the maximum number of files you can
simultaneously open, the maximum number of files you can watch using
inotify(2) isn't that large. Maybe just a single instance of mold is
fine with inotify(2), but it may fail if you run multiple of it.
The other reason for not doing it is because mold is quite fast
without it anyway. Invoking stat(2) on each file for file update
check takes less than 100 milliseconds for Chrome, and if most of
the input files are not updated, parsing updated files takes almost
no time.
+450
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#include "mold.h"
enum {
R_TLS_GOTIE = R_END + 1,
R_TLS_LE,
R_TLS_IE,
R_TLS_GD,
R_TLS_LD,
R_TLS_GOTDESC,
R_TLS_GOTDESC_RELAX,
R_TLS_DESC_CALL_RELAX,
R_TPOFF,
};
template <>
void PltSection<I386>::copy_buf(Context<I386> &ctx) {
u8 *buf = ctx.buf + this->shdr.sh_offset;
// Write PLT header
if (ctx.arg.pic) {
static const u8 plt0[] = {
0xff, 0xb3, 0x04, 0, 0, 0, // pushl 4(%ebx)
0xff, 0xa3, 0x08, 0, 0, 0, // jmp *8(%ebx)
0x90, 0x90, 0x90, 0x90, // nop
};
memcpy(buf, plt0, sizeof(plt0));
} else {
static const u8 plt0[] = {
0xff, 0x35, 0, 0, 0, 0, // pushl (GOTPLT+4)
0xff, 0x25, 0, 0, 0, 0, // jmp *(GOTPLT+8)
0x90, 0x90, 0x90, 0x90, // nop
};
memcpy(buf, plt0, sizeof(plt0));
*(u32 *)(buf + 2) = ctx.gotplt->shdr.sh_addr + 4;
*(u32 *)(buf + 8) = ctx.gotplt->shdr.sh_addr + 8;
}
// Write PLT entries
i64 relplt_idx = 0;
for (Symbol<I386> *sym : symbols) {
u8 *ent = buf + sym->get_plt_idx(ctx) * I386::plt_size;
if (ctx.arg.pic) {
static const u8 data[] = {
0xff, 0xa3, 0, 0, 0, 0, // jmp *foo@GOT(%ebx)
0x68, 0, 0, 0, 0, // pushl $reloc_offset
0xe9, 0, 0, 0, 0, // jmp .PLT0@PC
};
memcpy(ent, data, sizeof(data));
*(u32 *)(ent + 2) = sym->get_gotplt_addr(ctx) - ctx.gotplt->shdr.sh_addr;
} else {
static const u8 data[] = {
0xff, 0x25, 0, 0, 0, 0, // jmp *foo@GOT
0x68, 0, 0, 0, 0, // pushl $reloc_offset
0xe9, 0, 0, 0, 0, // jmp .PLT0@PC
};
memcpy(ent, data, sizeof(data));
*(u32 *)(ent + 2) = sym->get_gotplt_addr(ctx);
}
*(u32 *)(ent + 7) = relplt_idx++ * sizeof(ElfRel<I386>);
*(u32 *)(ent + 12) = this->shdr.sh_addr - sym->get_plt_addr(ctx) - 16;
}
}
template <>
void PltGotSection<I386>::copy_buf(Context<I386> &ctx) {
u8 *buf = ctx.buf + this->shdr.sh_offset;
if (ctx.arg.pic) {
static const u8 data[] = {
0xff, 0xa3, 0, 0, 0, 0, // jmp *foo@GOT(%ebx)
0x66, 0x90, // nop
};
for (i64 i = 0; i < symbols.size(); i++) {
u8 *ent = buf + i * sizeof(data);
memcpy(ent, data, sizeof(data));
*(u32 *)(ent + 2) = symbols[i]->get_got_addr(ctx) - ctx.gotplt->shdr.sh_addr;
}
} else {
static const u8 data[] = {
0xff, 0x25, 0, 0, 0, 0, // jmp *foo@GOT
0x66, 0x90, // nop
};
for (i64 i = 0; i < symbols.size(); i++) {
u8 *ent = buf + i * sizeof(data);
memcpy(ent, data, sizeof(data));
*(u32 *)(ent + 2) = symbols[i]->get_got_addr(ctx);
}
}
}
template <>
void EhFrameSection<I386>::apply_reloc(Context<I386> &ctx,
ElfRel<I386> &rel,
u64 loc, u64 val) {
u8 *base = ctx.buf + this->shdr.sh_offset;
switch (rel.r_type) {
case R_386_NONE:
return;
case R_386_32:
*(u32 *)(base + loc) = val;
return;
case R_386_PC32:
*(u32 *)(base + loc) = val - this->shdr.sh_addr - loc;
return;
}
unreachable(ctx);
}
static void write_val(Context<I386> &ctx, u64 r_type, u8 *loc, u64 val) {
switch (r_type) {
case R_386_NONE:
return;
case R_386_8:
case R_386_PC8:
*loc += val;
return;
case R_386_16:
case R_386_PC16:
*(u16 *)loc += val;
return;
case R_386_32:
case R_386_PC32:
case R_386_GOT32:
case R_386_GOT32X:
case R_386_PLT32:
case R_386_GOTOFF:
case R_386_GOTPC:
case R_386_TLS_LDM:
case R_386_TLS_GOTIE:
case R_386_TLS_LE:
case R_386_TLS_IE:
case R_386_TLS_GD:
case R_386_TLS_LDO_32:
case R_386_SIZE32:
case R_386_TLS_GOTDESC:
*(u32 *)loc += val;
return;
}
unreachable(ctx);
}
template <>
void InputSection<I386>::apply_reloc_alloc(Context<I386> &ctx, u8 *base) {
ElfRel<I386> *dynrel = nullptr;
std::span<ElfRel<I386>> rels = get_rels(ctx);
i64 frag_idx = 0;
if (ctx.reldyn)
dynrel = (ElfRel<I386> *)(ctx.buf + ctx.reldyn->shdr.sh_offset +
file.reldyn_offset + this->reldyn_offset);
for (i64 i = 0; i < rels.size(); i++) {
const ElfRel<I386> &rel = rels[i];
Symbol<I386> &sym = *file.symbols[rel.r_sym];
u8 *loc = base + rel.r_offset;
const SectionFragmentRef<I386> *ref = nullptr;
if (rel_fragments && rel_fragments[frag_idx].idx == i)
ref = &rel_fragments[frag_idx++];
auto write = [&](u64 val) {
write_val(ctx, rel.r_type, loc, val);
};
#define S (ref ? ref->frag->get_addr(ctx) : sym.get_addr(ctx))
#define A (ref ? ref->addend : 0)
#define P (output_section->shdr.sh_addr + offset + rel.r_offset)
#define G (sym.get_got_addr(ctx) - ctx.got->shdr.sh_addr)
#define GOTPLT ctx.gotplt->shdr.sh_addr
switch (rel_types[i]) {
case R_NONE:
break;
case R_ABS:
write(S + A);
break;
case R_BASEREL:
*dynrel++ = {P, R_386_RELATIVE, 0};
*(u32 *)loc += S + A;
break;
case R_DYN:
*dynrel++ = {P, R_386_32, (u32)sym.get_dynsym_idx(ctx)};
*(u32 *)loc += A;
break;
case R_PC:
write(S + A - P);
break;
case R_GOT:
write(sym.get_got_addr(ctx) + A - GOTPLT);
break;
case R_GOTOFF:
write(S + A - GOTPLT);
break;
case R_GOTPC:
write(GOTPLT + A - P);
break;
case R_GOTPCREL:
write(G + GOTPLT + A - P);
break;
case R_TLS_GOTIE:
write(sym.get_gottp_addr(ctx) + A - GOTPLT);
break;
case R_TLS_LE:
write(S + A - ctx.tls_end);
break;
case R_TLS_IE:
write(sym.get_gottp_addr(ctx) + A);
break;
case R_TLS_GD:
write(sym.get_tlsgd_addr(ctx) + A - GOTPLT);
break;
case R_TLS_LD:
write(ctx.got->get_tlsld_addr(ctx) + A - GOTPLT);
break;
case R_TPOFF:
write(S + A - ctx.tls_begin);
break;
case R_TLS_GOTDESC:
write(sym.get_tlsdesc_addr(ctx) + A - GOTPLT);
break;
case R_TLS_GOTDESC_RELAX: {
static const u8 insn[] = {
0x8d, 0x05, 0, 0, 0, 0, // lea 0, %eax
};
memcpy(loc - 2, insn, sizeof(insn));
write(S + A - ctx.tls_end);
break;
}
case R_TLS_DESC_CALL_RELAX:
// call *(%rax) -> nop
loc[0] = 0x66;
loc[1] = 0x90;
break;
case R_SIZE:
write(sym.esym().st_size + A);
break;
default:
unreachable(ctx);
}
#undef S
#undef A
#undef P
#undef G
#undef GOTPLT
}
}
template <>
void InputSection<I386>::apply_reloc_nonalloc(Context<I386> &ctx, u8 *base) {
std::span<ElfRel<I386>> rels = get_rels(ctx);
i64 frag_idx = 0;
for (i64 i = 0; i < rels.size(); i++) {
const ElfRel<I386> &rel = rels[i];
if (rel.r_type == R_386_NONE)
continue;
Symbol<I386> &sym = *file.symbols[rel.r_sym];
u8 *loc = base + rel.r_offset;
if (!sym.file) {
report_undef(ctx, sym);
continue;
}
const SectionFragmentRef<I386> *ref = nullptr;
if (rel_fragments && rel_fragments[frag_idx].idx == i)
ref = &rel_fragments[frag_idx++];
auto write = [&](u64 val) {
write_val(ctx, rel.r_type, loc, val);
};
switch (rel.r_type) {
case R_386_8:
case R_386_16:
case R_386_32:
case R_386_PC8:
case R_386_PC16:
case R_386_PC32:
case R_386_GOTPC:
if (ref)
write(ref->frag->get_addr(ctx) + ref->addend);
else
write(sym.get_addr(ctx));
break;
case R_386_GOTOFF:
write(sym.get_addr(ctx) - ctx.got->shdr.sh_addr);
break;
case R_386_TLS_LDO_32:
write(sym.get_addr(ctx) - ctx.tls_begin);
break;
case R_386_SIZE32:
write(sym.esym().st_size);
break;
default:
Fatal(ctx) << *this << ": invalid relocation for non-allocated sections: "
<< rel_to_string<I386>(rel.r_type);
break;
}
}
}
template <>
void InputSection<I386>::scan_relocations(Context<I386> &ctx) {
assert(shdr.sh_flags & SHF_ALLOC);
this->reldyn_offset = file.num_dynrel * sizeof(ElfRel<I386>);
std::span<ElfRel<I386>> rels = get_rels(ctx);
bool is_writable = (shdr.sh_flags & SHF_WRITE);
// Scan relocations
for (i64 i = 0; i < rels.size(); i++) {
const ElfRel<I386> &rel = rels[i];
if (rel.r_type == R_386_NONE) {
rel_types[i] = R_NONE;
break;
}
Symbol<I386> &sym = *file.symbols[rel.r_sym];
u8 *loc = (u8 *)(contents.data() + rel.r_offset);
if (!sym.file) {
report_undef(ctx, sym);
continue;
}
if (sym.get_type() == STT_GNU_IFUNC) {
sym.flags |= NEEDS_GOT;
sym.flags |= NEEDS_PLT;
}
switch (rel.r_type) {
case R_386_8:
case R_386_16: {
Action table[][4] = {
// Absolute Local Imported data Imported code
{ NONE, ERROR, ERROR, ERROR }, // DSO
{ NONE, ERROR, ERROR, ERROR }, // PIE
{ NONE, NONE, COPYREL, PLT }, // PDE
};
dispatch(ctx, table, R_ABS, i);
break;
}
case R_386_32: {
Action table[][4] = {
// Absolute Local Imported data Imported code
{ NONE, BASEREL, DYNREL, DYNREL }, // DSO
{ NONE, BASEREL, DYNREL, DYNREL }, // PIE
{ NONE, NONE, DYNREL, PLT }, // PDE
};
dispatch(ctx, table, R_ABS, i);
break;
}
case R_386_PC8:
case R_386_PC16: {
Action table[][4] = {
// Absolute Local Imported data Imported code
{ ERROR, NONE, ERROR, ERROR }, // DSO
{ ERROR, NONE, COPYREL, PLT }, // PIE
{ NONE, NONE, COPYREL, PLT }, // PDE
};
dispatch(ctx, table, R_PC, i);
break;
}
case R_386_PC32: {
Action table[][4] = {
// Absolute Local Imported data Imported code
{ BASEREL, NONE, ERROR, ERROR }, // DSO
{ BASEREL, NONE, COPYREL, PLT }, // PIE
{ NONE, NONE, COPYREL, PLT }, // PDE
};
dispatch(ctx, table, R_PC, i);
break;
}
case R_386_GOT32:
case R_386_GOT32X:
sym.flags |= NEEDS_GOT;
rel_types[i] = R_GOT;
break;
case R_386_PLT32:
if (sym.is_imported)
sym.flags |= NEEDS_PLT;
rel_types[i] = R_PC;
break;
case R_386_GOTOFF:
rel_types[i] = R_GOTOFF;
break;
case R_386_GOTPC:
sym.flags |= NEEDS_GOT;
rel_types[i] = R_GOTPC;
break;
case R_386_TLS_GOTIE:
sym.flags |= NEEDS_GOTTP;
rel_types[i] = R_TLS_GOTIE;
break;
case R_386_TLS_LE:
sym.flags |= NEEDS_GOTTP;
rel_types[i] = R_TLS_LE;
break;
case R_386_TLS_IE:
sym.flags |= NEEDS_GOTTP;
rel_types[i] = R_TLS_IE;
break;
case R_386_TLS_GD:
sym.flags |= NEEDS_TLSGD;
rel_types[i] = R_TLS_GD;
break;
case R_386_TLS_LDM:
sym.flags |= NEEDS_TLSLD;
rel_types[i] = R_TLS_LD;
break;
case R_386_TLS_LDO_32:
rel_types[i] = R_TPOFF;
break;
case R_386_SIZE32:
rel_types[i] = R_SIZE;
break;
case R_386_TLS_GOTDESC:
if (ctx.arg.relax && !ctx.arg.shared) {
rel_types[i] = R_TLS_GOTDESC_RELAX;
} else {
sym.flags |= NEEDS_TLSDESC;
rel_types[i] = R_TLS_GOTDESC;
}
break;
case R_386_TLS_DESC_CALL:
if (ctx.arg.relax && !ctx.arg.shared)
rel_types[i] = R_TLS_DESC_CALL_RELAX;
else
rel_types[i] = R_NONE;
break;
default:
Error(ctx) << *this << ": unknown relocation: "
<< rel_to_string<I386>(rel.r_type);
}
}
}
+687
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#include "mold.h"
enum {
R_GOTPCRELX_RELAX = R_END + 1,
R_REX_GOTPCRELX_RELAX,
R_TLSGD,
R_TLSGD_RELAX_LE,
R_TLSLD,
R_TLSLD_RELAX_LE,
R_DTPOFF,
R_DTPOFF_RELAX,
R_TPOFF,
R_GOTTPOFF,
R_GOTTPOFF_RELAX,
R_GOTPC_TLSDESC,
R_GOTPC_TLSDESC_RELAX_LE,
R_TLSDESC_CALL_RELAX,
};
template <>
void PltSection<X86_64>::copy_buf(Context<X86_64> &ctx) {
u8 *buf = ctx.buf + this->shdr.sh_offset;
// Write PLT header
static const u8 plt0[] = {
0xff, 0x35, 0, 0, 0, 0, // pushq GOTPLT+8(%rip)
0xff, 0x25, 0, 0, 0, 0, // jmp *GOTPLT+16(%rip)
0x0f, 0x1f, 0x40, 0x00, // nop
};
memcpy(buf, plt0, sizeof(plt0));
*(u32 *)(buf + 2) = ctx.gotplt->shdr.sh_addr - this->shdr.sh_addr + 2;
*(u32 *)(buf + 8) = ctx.gotplt->shdr.sh_addr - this->shdr.sh_addr + 4;
// Write PLT entries
i64 relplt_idx = 0;
static const u8 data[] = {
0xff, 0x25, 0, 0, 0, 0, // jmp *foo@GOTPLT
0x68, 0, 0, 0, 0, // push $index_in_relplt
0xe9, 0, 0, 0, 0, // jmp PLT[0]
};
for (Symbol<X86_64> *sym : symbols) {
u8 *ent = buf + sym->get_plt_idx(ctx) * X86_64::plt_size;
memcpy(ent, data, sizeof(data));
*(u32 *)(ent + 2) = sym->get_gotplt_addr(ctx) - sym->get_plt_addr(ctx) - 6;
*(u32 *)(ent + 7) = relplt_idx++;
*(u32 *)(ent + 12) = this->shdr.sh_addr - sym->get_plt_addr(ctx) - 16;
}
}
template <>
void PltGotSection<X86_64>::copy_buf(Context<X86_64> &ctx) {
u8 *buf = ctx.buf + this->shdr.sh_offset;
static const u8 data[] = {
0xff, 0x25, 0, 0, 0, 0, // jmp *foo@GOT
0x66, 0x90, // nop
};
for (Symbol<X86_64> *sym : symbols) {
u8 *ent = buf + sym->get_pltgot_idx(ctx) * X86_64::pltgot_size;
memcpy(ent, data, sizeof(data));
*(u32 *)(ent + 2) = sym->get_got_addr(ctx) - sym->get_plt_addr(ctx) - 6;
}
}
template <>
void EhFrameSection<X86_64>::apply_reloc(Context<X86_64> &ctx,
ElfRel<X86_64> &rel,
u64 loc, u64 val) {
u8 *base = ctx.buf + this->shdr.sh_offset;
switch (rel.r_type) {
case R_X86_64_NONE:
return;
case R_X86_64_32:
*(u32 *)(base + loc) = val;
return;
case R_X86_64_64:
*(u64 *)(base + loc) = val;
return;
case R_X86_64_PC32:
*(u32 *)(base + loc) = val - this->shdr.sh_addr - loc;
return;
case R_X86_64_PC64:
*(u64 *)(base + loc) = val - this->shdr.sh_addr - loc;
return;
}
unreachable(ctx);
}
static void overflow_check(Context<X86_64> &ctx, InputSection<X86_64> *sec,
Symbol<X86_64> &sym, u64 r_type, u64 val) {
switch (r_type) {
case R_X86_64_8:
if (val != (u8)val)
Error(ctx) << *sec << ": relocation R_X86_64_8 against " << sym
<< " out of range: " << val << " is not in [0, 255]";
return;
case R_X86_64_PC8:
if (val != (i8)val)
Error(ctx) << *sec << ": relocation R_X86_64_PC8 against " << sym
<< " out of range: " << (i64)val << " is not in [-128, 127]";
return;
case R_X86_64_16:
if (val != (u16)val)
Error(ctx) << *sec << ": relocation R_X86_64_16 against " << sym
<< " out of range: " << val << " is not in [0, 65535]";
return;
case R_X86_64_PC16:
if (val != (i16)val)
Error(ctx) << *sec << ": relocation R_X86_64_PC16 against " << sym
<< " out of range: " << (i64)val
<< " is not in [-32768, 32767]";
return;
case R_X86_64_32:
if (val != (u32)val)
Error(ctx) << *sec << ": relocation R_X86_64_32 against " << sym
<< " out of range: " << val << " is not in [0, 4294967296]";
return;
case R_X86_64_32S:
case R_X86_64_PC32:
case R_X86_64_GOT32:
case R_X86_64_GOTPC32:
case R_X86_64_GOTPCREL:
case R_X86_64_GOTPCRELX:
case R_X86_64_REX_GOTPCRELX:
case R_X86_64_PLT32:
case R_X86_64_TLSGD:
case R_X86_64_TLSLD:
case R_X86_64_TPOFF32:
case R_X86_64_DTPOFF32:
case R_X86_64_GOTTPOFF:
case R_X86_64_GOTPC32_TLSDESC:
case R_X86_64_SIZE32:
case R_X86_64_TLSDESC_CALL:
if (val != (i32)val)
Error(ctx) << *sec << ": relocation " << rel_to_string<X86_64>(r_type)
<< " against " << sym << " out of range: " << (i64)val
<< " is not in [-2147483648, 2147483647]";
return;
case R_X86_64_NONE:
case R_X86_64_64:
case R_X86_64_PC64:
case R_X86_64_TPOFF64:
case R_X86_64_DTPOFF64:
case R_X86_64_GOT64:
case R_X86_64_GOTPCREL64:
case R_X86_64_GOTPC64:
case R_X86_64_SIZE64:
return;
}
unreachable(ctx);
}
static void write_val(Context<X86_64> &ctx, u64 r_type, u8 *loc, u64 val) {
switch (r_type) {
case R_X86_64_NONE:
return;
case R_X86_64_8:
case R_X86_64_PC8:
*loc = val;
return;
case R_X86_64_16:
case R_X86_64_PC16:
*(u16 *)loc = val;
return;
case R_X86_64_32:
case R_X86_64_32S:
case R_X86_64_PC32:
case R_X86_64_GOT32:
case R_X86_64_GOTPC32:
case R_X86_64_GOTPCREL:
case R_X86_64_GOTPCRELX:
case R_X86_64_REX_GOTPCRELX:
case R_X86_64_PLT32:
case R_X86_64_TLSGD:
case R_X86_64_TLSLD:
case R_X86_64_TPOFF32:
case R_X86_64_DTPOFF32:
case R_X86_64_GOTTPOFF:
case R_X86_64_GOTPC32_TLSDESC:
case R_X86_64_SIZE32:
case R_X86_64_TLSDESC_CALL:
*(u32 *)loc = val;
return;
case R_X86_64_64:
case R_X86_64_PC64:
case R_X86_64_TPOFF64:
case R_X86_64_DTPOFF64:
case R_X86_64_GOT64:
case R_X86_64_GOTPCREL64:
case R_X86_64_GOTPC64:
case R_X86_64_SIZE64:
*(u64 *)loc = val;
return;
}
unreachable(ctx);
}
static u32 relax_gotpcrelx(u8 *loc) {
switch ((loc[0] << 8) | loc[1]) {
case 0xff15: return 0x90e8; // call *0(%rip) -> call 0
case 0xff25: return 0x90e9; // jmp *0(%rip) -> jmp 0
}
return 0;
}
static u32 relax_rex_gotpcrelx(u8 *loc) {
switch ((loc[0] << 16) | (loc[1] << 8) | loc[2]) {
case 0x488b05: return 0x488d05; // mov 0(%rip), %rax -> lea 0(%rip), %rax
case 0x488b0d: return 0x488d0d; // mov 0(%rip), %rcx -> lea 0(%rip), %rcx
case 0x488b15: return 0x488d15; // mov 0(%rip), %rdx -> lea 0(%rip), %rdx
case 0x488b1d: return 0x488d1d; // mov 0(%rip), %rbx -> lea 0(%rip), %rbx
case 0x488b25: return 0x488d25; // mov 0(%rip), %rsp -> lea 0(%rip), %rsp
case 0x488b2d: return 0x488d2d; // mov 0(%rip), %rbp -> lea 0(%rip), %rbp
case 0x488b35: return 0x488d35; // mov 0(%rip), %rsi -> lea 0(%rip), %rsi
case 0x488b3d: return 0x488d3d; // mov 0(%rip), %rdi -> lea 0(%rip), %rdi
case 0x4c8b05: return 0x4c8d05; // mov 0(%rip), %r8 -> lea 0(%rip), %r8
case 0x4c8b0d: return 0x4c8d0d; // mov 0(%rip), %r9 -> lea 0(%rip), %r9
case 0x4c8b15: return 0x4c8d15; // mov 0(%rip), %r10 -> lea 0(%rip), %r10
case 0x4c8b1d: return 0x4c8d1d; // mov 0(%rip), %r11 -> lea 0(%rip), %r11
case 0x4c8b25: return 0x4c8d25; // mov 0(%rip), %r12 -> lea 0(%rip), %r12
case 0x4c8b2d: return 0x4c8d2d; // mov 0(%rip), %r13 -> lea 0(%rip), %r13
case 0x4c8b35: return 0x4c8d35; // mov 0(%rip), %r14 -> lea 0(%rip), %r14
case 0x4c8b3d: return 0x4c8d3d; // mov 0(%rip), %r15 -> lea 0(%rip), %r15
}
return 0;
}
static u32 relax_gottpoff(u8 *loc) {
switch ((loc[0] << 16) | (loc[1] << 8) | loc[2]) {
case 0x488b05: return 0x48c7c0; // mov 0(%rip), %rax -> mov $0, %rax
case 0x488b0d: return 0x48c7c1; // mov 0(%rip), %rcx -> mov $0, %rcx
case 0x488b15: return 0x48c7c2; // mov 0(%rip), %rdx -> mov $0, %rdx
case 0x488b1d: return 0x48c7c3; // mov 0(%rip), %rbx -> mov $0, %rbx
case 0x488b25: return 0x48c7c4; // mov 0(%rip), %rsp -> mov $0, %rsp
case 0x488b2d: return 0x48c7c5; // mov 0(%rip), %rbp -> mov $0, %rbp
case 0x488b35: return 0x48c7c6; // mov 0(%rip), %rsi -> mov $0, %rsi
case 0x488b3d: return 0x48c7c7; // mov 0(%rip), %rdi -> mov $0, %rdi
case 0x4c8b05: return 0x49c7c0; // mov 0(%rip), %r8 -> mov $0, %r8
case 0x4c8b0d: return 0x49c7c1; // mov 0(%rip), %r9 -> mov $0, %r9
case 0x4c8b15: return 0x49c7c2; // mov 0(%rip), %r10 -> mov $0, %r10
case 0x4c8b1d: return 0x49c7c3; // mov 0(%rip), %r11 -> mov $0, %r11
case 0x4c8b25: return 0x49c7c4; // mov 0(%rip), %r12 -> mov $0, %r12
case 0x4c8b2d: return 0x49c7c5; // mov 0(%rip), %r13 -> mov $0, %r13
case 0x4c8b35: return 0x49c7c6; // mov 0(%rip), %r14 -> mov $0, %r14
case 0x4c8b3d: return 0x49c7c7; // mov 0(%rip), %r15 -> mov $0, %r15
}
return 0;
}
// Apply relocations to SHF_ALLOC sections (i.e. sections that are
// mapped to memory at runtime) based on the result of
// scan_relocations().
template <>
void InputSection<X86_64>::apply_reloc_alloc(Context<X86_64> &ctx, u8 *base) {
ElfRel<X86_64> *dynrel = nullptr;
std::span<ElfRel<X86_64>> rels = get_rels(ctx);
i64 frag_idx = 0;
if (ctx.reldyn)
dynrel = (ElfRel<X86_64> *)(ctx.buf + ctx.reldyn->shdr.sh_offset +
file.reldyn_offset + this->reldyn_offset);
for (i64 i = 0; i < rels.size(); i++) {
const ElfRel<X86_64> &rel = rels[i];
Symbol<X86_64> &sym = *file.symbols[rel.r_sym];
u8 *loc = base + rel.r_offset;
const SectionFragmentRef<X86_64> *ref = nullptr;
if (rel_fragments && rel_fragments[frag_idx].idx == i)
ref = &rel_fragments[frag_idx++];
auto write = [&](u64 val) {
overflow_check(ctx, this, sym, rel.r_type, val);
write_val(ctx, rel.r_type, loc, val);
};
#define S (ref ? ref->frag->get_addr(ctx) : sym.get_addr(ctx))
#define A (ref ? ref->addend : rel.r_addend)
#define P (output_section->shdr.sh_addr + offset + rel.r_offset)
#define G (sym.get_got_addr(ctx) - ctx.got->shdr.sh_addr)
#define GOT ctx.got->shdr.sh_addr
switch (rel_types[i]) {
case R_NONE:
break;
case R_ABS:
write(S + A);
break;
case R_BASEREL:
*dynrel++ = {P, R_X86_64_RELATIVE, 0, (i64)(S + A)};
*(u64 *)loc = S + A;
break;
case R_DYN:
*dynrel++ = {P, R_X86_64_64, (u32)sym.get_dynsym_idx(ctx), A};
*(u64 *)loc = A;
break;
case R_PC:
write(S + A - P);
break;
case R_GOT:
write(G + A);
break;
case R_GOTPC:
write(GOT + A - P);
break;
case R_GOTPCREL:
write(G + GOT + A - P);
break;
case R_GOTPCRELX_RELAX: {
u32 insn = relax_gotpcrelx(loc - 2);
loc[-2] = insn >> 8;
loc[-1] = insn;
write(S + A - P);
break;
}
case R_REX_GOTPCRELX_RELAX: {
u32 insn = relax_rex_gotpcrelx(loc - 3);
loc[-3] = insn >> 16;
loc[-2] = insn >> 8;
loc[-1] = insn;
write(S + A - P);
break;
}
case R_TLSGD:
write(sym.get_tlsgd_addr(ctx) + A - P);
break;
case R_TLSGD_RELAX_LE: {
// Relax GD to LE
static const u8 insn[] = {
0x64, 0x48, 0x8b, 0x04, 0x25, 0, 0, 0, 0, // mov %fs:0, %rax
0x48, 0x8d, 0x80, 0, 0, 0, 0, // lea 0(%rax), %rax
};
memcpy(loc - 4, insn, sizeof(insn));
*(u32 *)(loc + 8) = S - ctx.tls_end + A + 4;
i++;
break;
}
case R_TLSLD:
write(ctx.got->get_tlsld_addr(ctx) + A - P);
break;
case R_TLSLD_RELAX_LE: {
// Relax LD to LE
static const u8 insn[] = {
0x66, 0x66, 0x66, // (padding)
0x64, 0x48, 0x8b, 0x04, 0x25, 0, 0, 0, 0, // mov %fs:0, %rax
};
memcpy(loc - 3, insn, sizeof(insn));
i++;
break;
}
case R_DTPOFF:
write(S + A - ctx.tls_begin);
break;
case R_DTPOFF_RELAX:
write(S + A - ctx.tls_end);
break;
case R_TPOFF:
write(S + A - ctx.tls_end);
break;
case R_GOTTPOFF:
write(sym.get_gottp_addr(ctx) + A - P);
break;
case R_GOTTPOFF_RELAX: {
u32 insn = relax_gottpoff(loc - 3);
loc[-3] = insn >> 16;
loc[-2] = insn >> 8;
loc[-1] = insn;
write(S + A - ctx.tls_end + 4);
break;
}
case R_GOTPC_TLSDESC:
write(sym.get_tlsdesc_addr(ctx) + A - P);
break;
case R_GOTPC_TLSDESC_RELAX_LE: {
static const u8 insn[] = {
0x48, 0xc7, 0xc0, 0, 0, 0, 0, // mov $0, %rax
};
memcpy(loc - 3, insn, sizeof(insn));
write(S + A - ctx.tls_end + 4);
break;
}
case R_SIZE:
write(sym.esym().st_size + A);
break;
case R_TLSDESC_CALL_RELAX:
// call *(%rax) -> nop
loc[0] = 0x66;
loc[1] = 0x90;
break;
default:
unreachable(ctx);
}
#undef S
#undef A
#undef P
#undef G
#undef GOT
}
}
// This function is responsible for applying relocations against
// non-SHF_ALLOC sections (i.e. sections that are not mapped to memory
// at runtime).
//
// Relocations against non-SHF_ALLOC sections are much easier to
// handle than that against SHF_ALLOC sections. It is because, since
// they are not mapped to memory, they don't contain any variable or
// function and never need PLT or GOT. Non-SHF_ALLOC sections are
// mostly debug info sections.
//
// Relocations against non-SHF_ALLOC sections are not scanned by
// scan_relocations.
template <>
void InputSection<X86_64>::apply_reloc_nonalloc(Context<X86_64> &ctx, u8 *base) {
std::span<ElfRel<X86_64>> rels = get_rels(ctx);
i64 frag_idx = 0;
for (i64 i = 0; i < rels.size(); i++) {
const ElfRel<X86_64> &rel = rels[i];
if (rel.r_type == R_X86_64_NONE)
continue;
Symbol<X86_64> &sym = *file.symbols[rel.r_sym];
u8 *loc = base + rel.r_offset;
if (!sym.file) {
report_undef(ctx, sym);
continue;
}
const SectionFragmentRef<X86_64> *ref = nullptr;
if (rel_fragments && rel_fragments[frag_idx].idx == i)
ref = &rel_fragments[frag_idx++];
auto write = [&](u64 val) {
overflow_check(ctx, this, sym, rel.r_type, val);
write_val(ctx, rel.r_type, loc, val);
};
switch (rel.r_type) {
case R_X86_64_8:
case R_X86_64_16:
case R_X86_64_32:
case R_X86_64_32S:
case R_X86_64_64:
if (ref)
write(ref->frag->get_addr(ctx) + ref->addend);
else
write(sym.get_addr(ctx) + rel.r_addend);
break;
case R_X86_64_DTPOFF32:
case R_X86_64_DTPOFF64:
write(sym.get_addr(ctx) + rel.r_addend - ctx.tls_begin);
break;
case R_X86_64_SIZE32:
case R_X86_64_SIZE64:
write(sym.esym().st_size + rel.r_addend);
break;
default:
Fatal(ctx) << *this << ": invalid relocation for non-allocated sections: "
<< rel_to_string<X86_64>(rel.r_type);
break;
}
}
}
// Linker has to create data structures in an output file to apply
// some type of relocations. For example, if a relocation refers a GOT
// or a PLT entry of a symbol, linker has to create an entry in .got
// or in .plt for that symbol. In order to fix the file layout, we
// need to scan relocations.
template <>
void InputSection<X86_64>::scan_relocations(Context<X86_64> &ctx) {
assert(shdr.sh_flags & SHF_ALLOC);
this->reldyn_offset = file.num_dynrel * sizeof(ElfRel<X86_64>);
std::span<ElfRel<X86_64>> rels = get_rels(ctx);
bool is_writable = (shdr.sh_flags & SHF_WRITE);
// Scan relocations
for (i64 i = 0; i < rels.size(); i++) {
const ElfRel<X86_64> &rel = rels[i];
if (rel.r_type == R_X86_64_NONE) {
rel_types[i] = R_NONE;
continue;
}
Symbol<X86_64> &sym = *file.symbols[rel.r_sym];
u8 *loc = (u8 *)(contents.data() + rel.r_offset);
if (!sym.file) {
report_undef(ctx, sym);
continue;
}
if (sym.get_type() == STT_GNU_IFUNC) {
sym.flags |= NEEDS_GOT;
sym.flags |= NEEDS_PLT;
}
switch (rel.r_type) {
case R_X86_64_8:
case R_X86_64_16:
case R_X86_64_32:
case R_X86_64_32S: {
// Dynamic linker does not support 8, 16 or 32-bit dynamic
// relocations for these types of relocations. We report an
// error if we cannot relocate them even at load-time.
Action table[][4] = {
// Absolute Local Imported data Imported code
{ NONE, ERROR, ERROR, ERROR }, // DSO
{ NONE, ERROR, ERROR, ERROR }, // PIE
{ NONE, NONE, COPYREL, PLT }, // PDE
};
dispatch(ctx, table, R_ABS, i);
break;
}
case R_X86_64_64: {
// Unlike the above, we can use R_X86_64_RELATIVE and R_86_64_64
// relocations.
Action table[][4] = {
// Absolute Local Imported data Imported code
{ NONE, BASEREL, DYNREL, DYNREL }, // DSO
{ NONE, BASEREL, DYNREL, DYNREL }, // PIE
{ NONE, NONE, DYNREL, PLT }, // PDE
};
dispatch(ctx, table, R_ABS, i);
break;
}
case R_X86_64_PC8:
case R_X86_64_PC16:
case R_X86_64_PC32: {
Action table[][4] = {
// Absolute Local Imported data Imported code
{ ERROR, NONE, ERROR, ERROR }, // DSO
{ ERROR, NONE, COPYREL, PLT }, // PIE
{ NONE, NONE, COPYREL, PLT }, // PDE
};
dispatch(ctx, table, R_PC, i);
break;
}
case R_X86_64_PC64: {
Action table[][4] = {
// Absolute Local Imported data Imported code
{ BASEREL, NONE, ERROR, ERROR }, // DSO
{ BASEREL, NONE, COPYREL, PLT }, // PIE
{ NONE, NONE, COPYREL, PLT }, // PDE
};
dispatch(ctx, table, R_PC, i);
break;
}
case R_X86_64_GOT32:
case R_X86_64_GOT64:
sym.flags |= NEEDS_GOT;
rel_types[i] = R_GOT;
break;
case R_X86_64_GOTPC32:
case R_X86_64_GOTPC64:
sym.flags |= NEEDS_GOT;
rel_types[i] = R_GOTPC;
break;
case R_X86_64_GOTPCREL:
case R_X86_64_GOTPCREL64:
sym.flags |= NEEDS_GOT;
rel_types[i] = R_GOTPCREL;
break;
case R_X86_64_GOTPCRELX: {
if (rel.r_addend != -4)
Fatal(ctx) << *this << ": bad r_addend for R_X86_64_GOTPCRELX";
if (ctx.arg.relax && !sym.is_imported && sym.is_relative(ctx) &&
relax_gotpcrelx(loc - 2)) {
rel_types[i] = R_GOTPCRELX_RELAX;
} else {
sym.flags |= NEEDS_GOT;
rel_types[i] = R_GOTPCREL;
}
break;
}
case R_X86_64_REX_GOTPCRELX:
if (rel.r_addend != -4)
Fatal(ctx) << *this << ": bad r_addend for R_X86_64_REX_GOTPCRELX";
if (ctx.arg.relax && !sym.is_imported && sym.is_relative(ctx) &&
relax_rex_gotpcrelx(loc - 3)) {
rel_types[i] = R_REX_GOTPCRELX_RELAX;
} else {
sym.flags |= NEEDS_GOT;
rel_types[i] = R_GOTPCREL;
}
break;
case R_X86_64_PLT32:
if (sym.is_imported)
sym.flags |= NEEDS_PLT;
rel_types[i] = R_PC;
break;
case R_X86_64_TLSGD: {
if (i + 1 == rels.size())
Fatal(ctx) << *this
<< ": TLSGD reloc must be followed by PLT32 or GOTPCREL";
if (ctx.arg.relax && !ctx.arg.shared && !sym.is_imported) {
rel_types[i++] = R_TLSGD_RELAX_LE;
} else {
sym.flags |= NEEDS_TLSGD;
rel_types[i] = R_TLSGD;
}
break;
}
case R_X86_64_TLSLD:
if (i + 1 == rels.size())
Fatal(ctx) << *this
<< ": TLSGD reloc must be followed by PLT32 or GOTPCREL";
if (sym.is_imported)
Fatal(ctx) << *this << ": TLSLD reloc refers external symbol " << sym;
if (ctx.arg.relax && !ctx.arg.shared) {
rel_types[i++] = R_TLSLD_RELAX_LE;
} else {
sym.flags |= NEEDS_TLSLD;
rel_types[i] = R_TLSLD;
}
break;
case R_X86_64_DTPOFF32:
case R_X86_64_DTPOFF64:
if (sym.is_imported)
Fatal(ctx) << *this << ": DTPOFF reloc refers external symbol " << sym;
if (ctx.arg.relax && !ctx.arg.shared)
rel_types[i] = R_DTPOFF_RELAX;
else
rel_types[i] = R_DTPOFF;
break;
case R_X86_64_TPOFF32:
case R_X86_64_TPOFF64:
rel_types[i] = R_TPOFF;
break;
case R_X86_64_GOTTPOFF:
ctx.has_gottp_rel = true;
if (ctx.arg.relax && !ctx.arg.shared && !sym.is_imported &&
relax_gottpoff(loc - 3)) {
rel_types[i] = R_GOTTPOFF_RELAX;
} else {
sym.flags |= NEEDS_GOTTP;
rel_types[i] = R_GOTTPOFF;
}
break;
case R_X86_64_GOTPC32_TLSDESC:
if (memcmp(loc - 3, "\x48\x8d\x05", 3))
Fatal(ctx) << *this << ": GOTPC32_TLSDESC relocation is used"
<< " against an invalid code sequence";
if (ctx.arg.relax && !ctx.arg.shared) {
rel_types[i] = R_GOTPC_TLSDESC_RELAX_LE;
} else {
sym.flags |= NEEDS_TLSDESC;
rel_types[i] = R_GOTPC_TLSDESC;
}
break;
case R_X86_64_SIZE32:
case R_X86_64_SIZE64:
rel_types[i] = R_SIZE;
break;
case R_X86_64_TLSDESC_CALL:
if (ctx.arg.relax && !ctx.arg.shared)
rel_types[i] = R_TLSDESC_CALL_RELAX;
else
rel_types[i] = R_NONE;
break;
default:
Error(ctx) << *this << ": unknown relocation: "
<< rel_to_string<X86_64>(rel.r_type);
}
}
}
+118
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@@ -0,0 +1,118 @@
#include "mold.h"
struct ArHdr {
char ar_name[16];
char ar_date[12];
char ar_uid[6];
char ar_gid[6];
char ar_mode[8];
char ar_size[10];
char ar_fmag[2];
};
template <typename E>
std::vector<MemoryMappedFile<E> *>
read_thin_archive_members(Context<E> &ctx, MemoryMappedFile<E> *mb) {
u8 *begin = mb->data(ctx);
u8 *data = begin + 8;
std::vector<MemoryMappedFile<E> *> vec;
std::string_view strtab;
while (data < begin + mb->size()) {
// Each header is aligned to a 2 byte boundary.
if ((begin - data) % 2)
data++;
ArHdr &hdr = *(ArHdr *)data;
u8 *body = data + sizeof(hdr);
u64 size = atol(hdr.ar_size);
// Read a string table.
if (!memcmp(hdr.ar_name, "// ", 3)) {
strtab = {(char *)body, size};
data = body + size;
continue;
}
// Skip a symbol table.
if (!memcmp(hdr.ar_name, "/ ", 2)) {
data = body + size;
continue;
}
if (hdr.ar_name[0] != '/')
Fatal(ctx) << mb->name << ": filename is not stored as a long filename";
const char *start = strtab.data() + atoi(hdr.ar_name + 1);
std::string name(start, (const char *)strstr(start, "/\n"));
std::string path = name.starts_with('/') ?
name : std::string(path_dirname(mb->name)) + "/" + name;
vec.push_back(MemoryMappedFile<E>::must_open(ctx, path));
data = body;
}
return vec;
}
template <typename E>
std::vector<MemoryMappedFile<E> *>
read_fat_archive_members(Context<E> &ctx, MemoryMappedFile<E> *mb) {
u8 *begin = mb->data(ctx);
u8 *data = begin + 8;
std::vector<MemoryMappedFile<E> *> vec;
std::string_view strtab;
while (begin + mb->size() - data >= 2) {
if ((begin - data) % 2)
data++;
ArHdr &hdr = *(ArHdr *)data;
u8 *body = data + sizeof(hdr);
u64 size = atol(hdr.ar_size);
data = body + size;
if (!memcmp(hdr.ar_name, "// ", 3)) {
strtab = {(char *)body, size};
continue;
}
if (!memcmp(hdr.ar_name, "/ ", 2) ||
!memcmp(hdr.ar_name, "__.SYMDEF/", 10))
continue;
std::string name;
if (hdr.ar_name[0] == '/') {
const char *start = strtab.data() + atoi(hdr.ar_name + 1);
name = {start, (const char *)strstr(start, "/\n")};
} else {
name = {hdr.ar_name, strchr(hdr.ar_name, '/')};
}
vec.push_back(mb->slice(ctx, name, body - begin, size));
}
return vec;
}
template <typename E>
std::vector<MemoryMappedFile<E> *>
read_archive_members(Context<E> &ctx, MemoryMappedFile<E> *mb) {
switch (get_file_type(ctx, mb)) {
case FileType::AR:
return read_fat_archive_members(ctx, mb);
case FileType::THIN_AR:
return read_thin_archive_members(ctx, mb);
default:
unreachable(ctx);
}
}
#define INSTANTIATE(E) \
template std::vector<MemoryMappedFile<E> *> \
read_fat_archive_members(Context<E> &, MemoryMappedFile<E> *); \
template std::vector<MemoryMappedFile<E> *> \
read_thin_archive_members(Context<E> &, MemoryMappedFile<E> *); \
template std::vector<MemoryMappedFile<E> *> \
read_archive_members(Context<E> &, MemoryMappedFile<E> *);
INSTANTIATE(X86_64);
INSTANTIATE(I386);
+40
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@@ -0,0 +1,40 @@
#!/bin/bash -x
# This is a shell script to build a statically-linked mold
# executable using Docker, so that it is easy to build mold
# on non-Ubuntu 20.04 machines.
#
# A docker image used for building mold is persistent.
# Run `docker image rm mold-build-ubuntu20` to remove the image
# from disk.
set -e
# If the existing file is not statically-linked, remove it.
[ -f mold ] && ! ldd mold 2>&1 | grep -q 'not a dynamic executable' && \
rm mold
cat <<EOF | docker build -t mold-build-ubuntu20 -
FROM ubuntu:20.04
RUN apt-get update && \
TZ=Europe/London apt-get install -y tzdata && \
apt-get install -y build-essential git clang lld cmake \
libstdc++-10-dev libxxhash-dev zlib1g-dev libssl-dev && \
rm -rf /var/lib/apt/lists/*
EOF
if ! [ -d oneTBB ]; then
git clone https://github.com/oneapi-src/oneTBB.git
(cd oneTBB; git checkout --quiet v2020.3)
fi
docker run -it --rm -v `pwd`/oneTBB:/oneTBB -u $(id -u):$(id -g) \
mold-build-ubuntu20 \
make -C /oneTBB -j$(nproc) extra_inc=big_iron.inc
tbb_bindir=$(ls -d oneTBB/build/linux_intel64_*_release)
docker run -it --rm -v `pwd`:/mold -u $(id -u):$(id -g) \
mold-build-ubuntu20 \
make -C /mold -j$(nproc) \
EXTRA_CPPFLAGS=-IoneTBB/include \
EXTRA_LDFLAGS="-fuse-ld=lld -static -L$tbb_bindir"
+850
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@@ -0,0 +1,850 @@
#include "mold.h"
#include <sstream>
#include <sys/stat.h>
#include <sys/types.h>
#include <tbb/global_control.h>
#include <unistd.h>
#include <unordered_set>
static const char helpmsg[] = R"(
Options:
--help Report usage information
-v, --version Report version information
-V Report version and target information
-(, --start-group Ignored
-), --end-group Ignored
-C DIR, --directory DIR Change to DIR before doing anything
-E, --export-dynamic Put symbols in the dynamic symbol table
--no-export-dynamic
-F LIBNAME, --filter LIBNAME
Set DT_FILTER to the specified value
-I FILE, --dynamic-linker FILE
Set dynamic linker path
--no-dynamic-linker
-L DIR, --library-path DIR Add DIR to library search path
-M, --print-map Write map file to stdout
-N, --omagic Do not page align data, do not make text readonly
--no-omagic
-O NUMBER Ignored
-S, --strip-debug Strip .debug_* sections
-T FILE, --script FILE Read linker script
-X, --discard-locals Discard temporary local symbols
-e SYMBOL, --entry SYMBOL Set program entry point
-f SHLIB, --auxiliary SHLIB Set DT_AUXILIARY to the specified value
-h LIBNAME, --soname LIBNAME
Set shared library name
-l LIBNAME Search for a given library
-m EMULATION Ignored
-o FILE, --output FILE Set output filename
-r, --relocatable Generate relocatable output
-s, --strip-all Strip .symtab section
-u SYMBOL, --undefined SYMBOL
Force to resolve SYMBOL
--Bdynamic Link against shared libraries (default)
--Bstatic Do not link against shared libraries
--Bsymbolic Bind global symbols locally
--Bsymbolic-functions Bind global functions locally
--Map FILE Write map file to a given file
--allow-multiple-definition Allow multiple definitions
--as-needed Only set DT_NEEDED if used
--no-as-needed
--build-id [none,md5,sha1,sha256,uuid,HEXSTRING]
Generate build ID
--no-build-id
--chroot DIR Set a given path to root directory
--color-diagnostics Ignored
--compress-debug-sections [none,zlib,zlib-gabi,zlib-gnu]
Compress .debug_* sections
--demangle Demangle C++ symbols in log messages (default)
--no-demangle
--disable-new-dtags Ignored
--dynamic-list Read a list of dynamic symbols
--eh-frame-hdr Create .eh_frame_hdr section
--no-eh-frame-hdr
--enable-new-dtags Ignored
--exclude-libs LIB,LIB,.. Mark all symbols in given libraries hidden
--fatal-warnings Ignored
--no-fatal-warnings Ignored
--fini SYMBOL Call SYMBOL at unload-time
--fork Spawn a child process (default)
--no-fork
--gc-sections Remove unreferenced sections
--no-gc-sections
--gdb-index Ignored
--hash-style [sysv,gnu,both]
Set hash style
--icf Fold identical code
--no-icf
--image-base ADDR Set the base address to a given value
--init SYMBOL Call SYMBOl at load-time
--no-undefined Report undefined symbols (even with --shared)
--perf Print performance statistics
--pie, --pic-executable Create a position independent executable
--no-pie, --no-pic-executable
--plugin Ignored
--plugin-opt Ignored
--pop-state Pop state of flags governing input file handling
--preload
--print-gc-sections Print removed unreferenced sections
--no-print-gc-sections
--print-icf-sections Print folded identical sections
--no-print-icf-sections
--push-state Pop state of flags governing input file handling
--quick-exit Use quick_exit to exit (default)
--no-quick-exit
--relax Optimize instructions (default)
--no-relax
--repro Embed input files to .repro section
--retain-symbols-file FILE Keep only symbols listed in FILE
--rpath DIR Add DIR to runtime search path
--rpath-link DIR Ignored
--run COMMAND ARG... Run COMMAND with mold as /usr/bin/ld
--shared, --Bshareable Create a share library
--sort-common Ignored
--sort-section Ignored
--spare-dynamic-tags NUMBER Reserve give number of tags in .dynamic section
--static Do not link against shared libraries
--stats Print input statistics
--sysroot DIR Set target system root directory
--thread-count COUNT Use COUNT number of threads
--threads Use multiple threads (default)
--no-threads
--trace Print name of each input file
--unique PATTERN Don't merge input sections that match a given pattern
--unresolved-symbols [report-all,ignore-all,ignore-in-object-files,ignore-in-shared-libs]
How to handle unresolved symbols
--version-script FILE Read version script
--warn-common Warn about common symbols
--no-warn-common
--warn-unresolved-symbols Report unresolved symbols as warnings
--error-unresolved-symbols
Report unresolved symbols as errors (default)
--whole-archive Include all objects from static archives
--no-whole-archive
--wrap SYMBOL Use wrapper function for a given symbol
-z defs Report undefined symbols (even with --shared)
-z nodefs
-z execstack Require executable stack
-z noexecstack
-z initfirst Mark DSO to be initialized first at runtime
-z interpose Mark object to interpose all DSOs but executable
-z keep-text-section-prefix Keep .text.{hot,unknown,unlikely,startup,exit} as separate sections in the final binary
-z nokeep-text-section-prefix
-z lazy Enable lazy function resolution (default)
-z nocopyreloc Do not create copy relocations
-z nodelete Mark DSO non-deletable at runtime
-z nodlopen Mark DSO not available to dlopen
-z nodump Mark DSO not available to dldump
-z now Disable lazy function resolution
-z origin Mark object requiring immediate $ORIGIN processing at runtime
-z relro Make some sections read-only after relocation (default)
-z norelro
-z text Report error if DT_TEXTREL is set
-z notext
-z textoff
mold: supported targets: elf32-i386 elf64-x86-64
mold: supported emulations: elf_i386 elf_x86_64)";
template <typename E>
static std::vector<std::string_view>
read_response_file(Context<E> &ctx, std::string_view path) {
std::vector<std::string_view> vec;
MemoryMappedFile<E> *mb =
MemoryMappedFile<E>::must_open(ctx, std::string(path));
u8 *data = mb->data(ctx);
auto read_quoted = [&](i64 i, char quote) {
std::string buf;
while (i < mb->size() && data[i] != quote) {
if (data[i] == '\\') {
buf.append(1, data[i + 1]);
i += 2;
} else {
buf.append(1, data[i++]);
}
}
if (i >= mb->size())
Fatal(ctx) << path << ": premature end of input";
vec.push_back(save_string(ctx, buf));
return i + 1;
};
auto read_unquoted = [&](i64 i) {
std::string buf;
while (i < mb->size() && !isspace(data[i]))
buf.append(1, data[i++]);
vec.push_back(save_string(ctx, buf));
return i;
};
for (i64 i = 0; i < mb->size();) {
if (isspace(data[i]))
i++;
else if (data[i] == '\'')
i = read_quoted(i + 1, '\'');
else if (data[i] == '\"')
i = read_quoted(i + 1, '\"');
else
i = read_unquoted(i);
}
return vec;
}
template <typename E>
std::vector<std::string_view>
expand_response_files(Context<E> &ctx, char **argv) {
std::vector<std::string_view> vec;
for (i64 i = 0; argv[i]; i++) {
if (argv[i][0] == '@')
append(vec, read_response_file(ctx, argv[i] + 1));
else
vec.push_back(argv[i]);
}
return vec;
}
static std::vector<std::string> add_dashes(std::string name) {
// Multi-letter linker options can be preceded by either a single
// dash or double dashes except ones starting with "o", which must
// be preceded by double dashes. For example, "-omagic" is
// interpreted as "-o magic". If you really want to specify the
// "omagic" option, you have to pass "--omagic".
if (name[0] == 'o')
return {"--" + name};
return {"-" + name, "--" + name};
}
template <typename E>
bool read_arg(Context<E> &ctx, std::span<std::string_view> &args,
std::string_view &arg, std::string name) {
if (name.size() == 1) {
if (args[0] == "-" + name) {
if (args.size() == 1)
Fatal(ctx) << "option -" << name << ": argument missing";
arg = args[1];
args = args.subspan(2);
return true;
}
if (args[0].starts_with("-" + name)) {
arg = args[0].substr(name.size() + 1);
args = args.subspan(1);
return true;
}
return false;
}
for (std::string opt : add_dashes(name)) {
if (args[0] == opt) {
if (args.size() == 1)
Fatal(ctx) << "option -" << name << ": argument missing";
arg = args[1];
args = args.subspan(2);
return true;
}
if (args[0].starts_with(opt + "=")) {
arg = args[0].substr(opt.size() + 1);
args = args.subspan(1);
return true;
}
}
return false;
}
bool read_flag(std::span<std::string_view> &args, std::string name) {
for (std::string opt : add_dashes(name)) {
if (args[0] == opt) {
args = args.subspan(1);
return true;
}
}
return false;
}
static bool read_z_flag(std::span<std::string_view> &args, std::string name) {
if (args.size() >= 2 && args[0] == "-z" && args[1] == name) {
args = args.subspan(2);
return true;
}
if (!args.empty() && args[0] == "-z" + name) {
args = args.subspan(1);
return true;
}
return false;
}
template <typename E>
std::string create_response_file(Context<E> &ctx) {
std::string buf;
std::stringstream out;
std::string cwd = get_current_dir();
out << "-C " << cwd.substr(1) << "\n";
if (cwd != "/") {
out << "--chroot ..";
i64 depth = std::count(cwd.begin(), cwd.end(), '/');
for (i64 i = 1; i < depth; i++)
out << "/..";
out << "\n";
}
for (i64 i = 1; i < ctx.cmdline_args.size(); i++) {
std::string_view arg = ctx.cmdline_args[i];
if (arg == "-repro" || arg == "--repro") {
i++;
continue;
}
out << arg << "\n";
}
return out.str();
}
template <typename E>
static i64 parse_hex(Context<E> &ctx, std::string opt, std::string_view value) {
if (!value.starts_with("0x") && !value.starts_with("0X"))
Fatal(ctx) << "option -" << opt << ": not a hexadecimal number";
value = value.substr(2);
if (value.find_first_not_of("0123456789abcdefABCDEF") != value.npos)
Fatal(ctx) << "option -" << opt << ": not a hexadecimal number";
return std::stol(std::string(value), nullptr, 16);
}
template <typename E>
static i64 parse_number(Context<E> &ctx, std::string opt,
std::string_view value) {
size_t nread;
i64 ret = std::stol(std::string(value), &nread, 0);
if (value.size() != nread)
Fatal(ctx) << "option -" << opt << ": not a number: " << value;
return ret;
}
template <typename E>
static std::vector<u8> parse_hex_build_id(Context<E> &ctx,
std::string_view arg) {
assert(arg.starts_with("0x") || arg.starts_with("0X"));
if (arg.size() % 2)
Fatal(ctx) << "invalid build-id: " << arg;
if (arg.substr(2).find_first_not_of("0123456789abcdefABCDEF") != arg.npos)
Fatal(ctx) << "invalid build-id: " << arg;
arg = arg.substr(2);
auto fn = [](char c) {
if ('0' <= c && c <= '9')
return c - '0';
if ('a' <= c && c <= 'f')
return c - 'a' + 10;
assert('A' <= c && c <= 'F');
return c - 'A' + 10;
};
std::vector<u8> vec(arg.size() / 2);
for (i64 i = 0; i < vec.size(); i++)
vec[i] = (fn(arg[i * 2]) << 4) | fn(arg[i * 2 + 1]);
return vec;
}
static std::vector<std::string_view>
split_by_comma_or_colon(std::string_view str) {
std::vector<std::string_view> vec;
for (;;) {
i64 pos = str.find_first_of(",:");
if (pos == str.npos) {
vec.push_back(str);
break;
}
vec.push_back(str.substr(0, pos));
str = str.substr(pos);
}
return vec;
}
static i64 get_default_thread_count() {
// mold doesn't scale above 32 threads.
int n = tbb::global_control::active_value(
tbb::global_control::max_allowed_parallelism);
return std::min(n, 32);
}
static std::string_view trim(std::string_view str) {
size_t pos = str.find_first_not_of(" \t");
if (pos == str.npos)
return "";
str = str.substr(pos);
pos = str.find_last_not_of(" \t");
if (pos == str.npos)
return str;
return str.substr(0, pos + 1);
}
template <typename E>
static void read_retain_symbols_file(Context<E> &ctx, std::string_view path) {
MemoryMappedFile<E> *mb =
MemoryMappedFile<E>::must_open(ctx, std::string(path));
std::string_view data((char *)mb->data(ctx), mb->size());
ctx.arg.retain_symbols_file.reset(new std::unordered_set<std::string_view>);
while (!data.empty()) {
size_t pos = data.find('\n');
std::string_view name;
if (pos == data.npos) {
name = data;
data = "";
} else {
name = data.substr(0, pos);
data = data.substr(pos + 1);
}
name = trim(name);
if (!name.empty())
ctx.arg.retain_symbols_file->insert(name);
}
}
static bool is_file(std::string_view path) {
struct stat st;
return stat(std::string(path).c_str(), &st) == 0 &&
(st.st_mode & S_IFMT) != S_IFDIR;
}
template <typename E>
void parse_nonpositional_args(Context<E> &ctx,
std::vector<std::string_view> &remaining) {
std::span<std::string_view> args = ctx.cmdline_args;
args = args.subspan(1);
ctx.arg.thread_count = get_default_thread_count();
bool version_shown = false;
while (!args.empty()) {
std::string_view arg;
if (read_flag(args, "help")) {
SyncOut(ctx) << "Usage: " << ctx.cmdline_args[0]
<< " [options] file...\n" << helpmsg;
exit(0);
}
if (read_arg(ctx, args, arg, "o") || read_arg(ctx, args, arg, "output")) {
ctx.arg.output = arg;
} else if (read_arg(ctx, args, arg, "dynamic-linker") ||
read_arg(ctx, args, arg, "I")) {
ctx.arg.dynamic_linker = arg;
} else if (read_arg(ctx, args, arg, "no-dynamic-linker")) {
ctx.arg.dynamic_linker = "";
} else if (read_flag(args, "v")) {
SyncOut(ctx) << get_version_string();
version_shown = true;
} else if (read_flag(args, "version")) {
SyncOut(ctx) << get_version_string();
exit(0);
} else if (read_flag(args, "V")) {
SyncOut(ctx) << get_version_string()
<< "\n Supported emulations:\n elf_x86_64\n elf_i386";
version_shown = true;
} else if (read_flag(args, "export-dynamic") || read_flag(args, "E")) {
ctx.arg.export_dynamic = true;
} else if (read_flag(args, "no-export-dynamic")) {
ctx.arg.export_dynamic = false;
} else if (read_flag(args, "Bsymbolic")) {
ctx.arg.Bsymbolic = true;
} else if (read_flag(args, "Bsymbolic-functions")) {
ctx.arg.Bsymbolic_functions = true;
} else if (read_arg(ctx, args, arg, "exclude-libs")) {
append(ctx.arg.exclude_libs, split_by_comma_or_colon(arg));
} else if (read_arg(ctx, args, arg, "e") ||
read_arg(ctx, args, arg, "entry")) {
ctx.arg.entry = arg;
} else if (read_arg(ctx, args, arg, "Map")) {
ctx.arg.Map = arg;
ctx.arg.print_map = true;
} else if (read_flag(args, "print-map") || read_flag(args, "M")) {
ctx.arg.print_map = true;
} else if (read_flag(args, "static") || read_flag(args, "Bstatic")) {
ctx.arg.is_static = true;
remaining.push_back("-Bstatic");
} else if (read_flag(args, "Bdynamic")) {
ctx.arg.is_static = false;
remaining.push_back("-Bdynamic");
} else if (read_flag(args, "shared") || read_flag(args, "Bshareable")) {
ctx.arg.shared = true;
} else if (read_arg(ctx, args, arg, "spare-dynamic-tags")) {
ctx.arg.spare_dynamic_tags = parse_number(ctx, "spare-dynamic-tags", arg);
} else if (read_flag(args, "demangle")) {
ctx.arg.demangle = true;
} else if (read_flag(args, "no-demangle")) {
ctx.arg.demangle = false;
} else if (read_arg(ctx, args, arg, "y") ||
read_arg(ctx, args, arg, "trace-symbol")) {
ctx.arg.trace_symbol.push_back(arg);
} else if (read_arg(ctx, args, arg, "filler")) {
ctx.arg.filler = parse_hex(ctx, "filler", arg);
} else if (read_arg(ctx, args, arg, "L") ||
read_arg(ctx, args, arg, "library-path")) {
ctx.arg.library_paths.push_back(arg);
} else if (read_arg(ctx, args, arg, "sysroot")) {
ctx.arg.sysroot = arg;
} else if (read_arg(ctx, args, arg, "unique")) {
ctx.arg.unique.reset(new std::regex(glob_to_regex(arg)));
} else if (read_arg(ctx, args, arg, "unresolved-symbols")) {
if (arg == "report-all" || arg == "ignore-in-shared-libs")
ctx.arg.unresolved_symbols = UnresolvedKind::ERROR;
else if (arg == "ignore-all" || arg == "ignore-in-object-files")
ctx.arg.unresolved_symbols = UnresolvedKind::IGNORE;
else
Fatal(ctx) << "unknown --unresolved-symbols argument: " << arg;
} else if (read_arg(ctx, args, arg, "u") ||
read_arg(ctx, args, arg, "undefined")) {
ctx.arg.undefined.push_back(arg);
} else if (read_arg(ctx, args, arg, "init")) {
ctx.arg.init = arg;
} else if (read_arg(ctx, args, arg, "fini")) {
ctx.arg.fini = arg;
} else if (read_arg(ctx, args, arg, "hash-style")) {
if (arg == "sysv") {
ctx.arg.hash_style_sysv = true;
ctx.arg.hash_style_gnu = false;
} else if (arg == "gnu") {
ctx.arg.hash_style_sysv = false;
ctx.arg.hash_style_gnu = true;
} else if (arg == "both") {
ctx.arg.hash_style_sysv = true;
ctx.arg.hash_style_gnu = true;
} else {
Fatal(ctx) << "invalid --hash-style argument: " << arg;
}
} else if (read_arg(ctx, args, arg, "soname") ||
read_arg(ctx, args, arg, "h")) {
ctx.arg.soname = arg;
} else if (read_flag(args, "allow-multiple-definition")) {
ctx.arg.allow_multiple_definition = true;
} else if (read_flag(args, "trace")) {
ctx.arg.trace = true;
} else if (read_flag(args, "eh-frame-hdr")) {
ctx.arg.eh_frame_hdr = true;
} else if (read_flag(args, "no-eh-frame-hdr")) {
ctx.arg.eh_frame_hdr = false;
} else if (read_flag(args, "pie") || read_flag(args, "pic-executable")) {
ctx.arg.pic = true;
ctx.arg.pie = true;
} else if (read_flag(args, "no-pie") ||
read_flag(args, "no-pic-executable")) {
ctx.arg.pic = false;
ctx.arg.pie = false;
} else if (read_flag(args, "relax")) {
ctx.arg.relax = true;
} else if (read_flag(args, "no-relax")) {
ctx.arg.relax = false;
} else if (read_flag(args, "r") || read_flag(args, "relocatable")) {
ctx.arg.relocatable = true;
} else if (read_flag(args, "perf")) {
ctx.arg.perf = true;
} else if (read_flag(args, "stats")) {
ctx.arg.stats = true;
Counter::enabled = true;
} else if (read_arg(ctx, args, arg, "C") ||
read_arg(ctx, args, arg, "directory")) {
ctx.arg.directory = arg;
} else if (read_arg(ctx, args, arg, "chroot")) {
ctx.arg.chroot = arg;
} else if (read_flag(args, "warn-common")) {
ctx.arg.warn_common = true;
} else if (read_flag(args, "no-warn-common")) {
ctx.arg.warn_common = false;
} else if (read_arg(ctx, args, arg, "compress-debug-sections")) {
if (arg == "zlib" || arg == "zlib-gabi")
ctx.arg.compress_debug_sections = COMPRESS_GABI;
else if (arg == "zlib-gnu")
ctx.arg.compress_debug_sections = COMPRESS_GNU;
else if (arg == "none")
ctx.arg.compress_debug_sections = COMPRESS_NONE;
else
Fatal(ctx) << "invalid --compress-debug-sections argument: " << arg;
} else if (read_arg(ctx, args, arg, "wrap")) {
ctx.arg.wrap.insert(arg);
} else if (read_flag(args, "omagic") || read_flag(args, "N")) {
ctx.arg.omagic = true;
ctx.arg.is_static = true;
} else if (read_flag(args, "no-omagic")) {
ctx.arg.omagic = false;
} else if (read_arg(ctx, args, arg, "retain-symbols-file")) {
read_retain_symbols_file(ctx, arg);
} else if (read_flag(args, "repro")) {
ctx.arg.repro = true;
} else if (read_z_flag(args, "now")) {
ctx.arg.z_now = true;
} else if (read_z_flag(args, "lazy")) {
ctx.arg.z_now = false;
} else if (read_z_flag(args, "execstack")) {
ctx.arg.z_execstack = true;
} else if (read_z_flag(args, "noexecstack")) {
ctx.arg.z_execstack = false;
} else if (read_z_flag(args, "relro")) {
ctx.arg.z_relro = true;
} else if (read_z_flag(args, "norelro")) {
ctx.arg.z_relro = false;
} else if (read_z_flag(args, "defs")) {
ctx.arg.z_defs = true;
} else if (read_z_flag(args, "nodefs")) {
ctx.arg.z_defs = false;
} else if (read_z_flag(args, "nodlopen")) {
ctx.arg.z_dlopen = false;
} else if (read_z_flag(args, "nodelete")) {
ctx.arg.z_delete = false;
} else if (read_z_flag(args, "nocopyreloc")) {
ctx.arg.z_copyreloc = false;
} else if (read_z_flag(args, "nodump")) {
ctx.arg.z_dump = false;
} else if (read_z_flag(args, "initfirst")) {
ctx.arg.z_initfirst = true;
} else if (read_z_flag(args, "interpose")) {
ctx.arg.z_interpose = true;
} else if (read_z_flag(args, "muldefs")) {
ctx.arg.allow_multiple_definition = true;
} else if (read_z_flag(args, "keep-text-section-prefix")) {
ctx.arg.z_keep_text_section_prefix = true;
} else if (read_z_flag(args, "nokeep-text-section-prefix")) {
ctx.arg.z_keep_text_section_prefix = false;
} else if (read_z_flag(args, "text")) {
ctx.arg.z_text = true;
} else if (read_z_flag(args, "notext") || read_z_flag(args, "textoff")) {
ctx.arg.z_text = false;
} else if (read_z_flag(args, "origin")) {
ctx.arg.z_origin = true;
} else if (read_flag(args, "no-undefined")) {
ctx.arg.z_defs = true;
} else if (read_flag(args, "fatal-warnings")) {
ctx.arg.fatal_warnings = true;
} else if (read_flag(args, "no-fatal-warnings")) {
ctx.arg.fatal_warnings = false;
} else if (read_flag(args, "fork")) {
ctx.arg.fork = true;
} else if (read_flag(args, "no-fork")) {
ctx.arg.fork = false;
} else if (read_flag(args, "gc-sections")) {
ctx.arg.gc_sections = true;
} else if (read_flag(args, "no-gc-sections")) {
ctx.arg.gc_sections = false;
} else if (read_flag(args, "print-gc-sections")) {
ctx.arg.print_gc_sections = true;
} else if (read_flag(args, "no-print-gc-sections")) {
ctx.arg.print_gc_sections = false;
} else if (read_arg(ctx, args, arg, "icf")) {
if (arg == "all")
ctx.arg.icf = true;
else if (arg == "none")
ctx.arg.icf = false;
else
Fatal(ctx) << "unknown --icf argument: " << arg;
} else if (read_flag(args, "no-icf")) {
ctx.arg.icf = false;
} else if (read_arg(ctx, args, arg, "image-base")) {
ctx.arg.image_base = parse_number(ctx, "image-base", arg);
} else if (read_flag(args, "quick-exit")) {
ctx.arg.quick_exit = true;
} else if (read_flag(args, "no-quick-exit")) {
ctx.arg.quick_exit = false;
} else if (read_flag(args, "print-icf-sections")) {
ctx.arg.print_icf_sections = true;
} else if (read_flag(args, "no-print-icf-sections")) {
ctx.arg.print_icf_sections = false;
} else if (read_flag(args, "quick-exit")) {
ctx.arg.quick_exit = true;
} else if (read_flag(args, "no-quick-exit")) {
ctx.arg.quick_exit = false;
} else if (read_arg(ctx, args, arg, "thread-count")) {
ctx.arg.thread_count = parse_number(ctx, "thread-count", arg);
} else if (read_flag(args, "threads")) {
ctx.arg.thread_count = get_default_thread_count();
} else if (read_flag(args, "no-threads")) {
ctx.arg.thread_count = 1;
} else if (read_flag(args, "discard-all") || read_flag(args, "x")) {
ctx.arg.discard_all = true;
} else if (read_flag(args, "discard-locals") || read_flag(args, "X")) {
ctx.arg.discard_locals = true;
} else if (read_flag(args, "strip-all") || read_flag(args, "s")) {
ctx.arg.strip_all = true;
} else if (read_flag(args, "strip-debug") || read_flag(args, "S")) {
ctx.arg.strip_all = true;
} else if (read_flag(args, "warn-unresolved-symbols")) {
ctx.arg.unresolved_symbols = UnresolvedKind::WARN;
} else if (read_flag(args, "error-unresolved-symbols")) {
ctx.arg.unresolved_symbols = UnresolvedKind::ERROR;
} else if (read_arg(ctx, args, arg, "rpath")) {
if (!ctx.arg.rpaths.empty())
ctx.arg.rpaths += ":";
ctx.arg.rpaths += arg;
} else if (read_arg(ctx, args, arg, "R")) {
if (is_file(arg))
Fatal(ctx) << "-R" << arg
<< ": -R as an alias for --just-symbols is not supported";
if (!ctx.arg.rpaths.empty())
ctx.arg.rpaths += ":";
ctx.arg.rpaths += arg;
} else if (read_flag(args, "build-id")) {
ctx.arg.build_id.kind = BuildId::HASH;
ctx.arg.build_id.hash_size = 20;
} else if (read_arg(ctx, args, arg, "build-id")) {
if (arg == "none") {
ctx.arg.build_id.kind = BuildId::NONE;
} else if (arg == "uuid") {
ctx.arg.build_id.kind = BuildId::UUID;
} else if (arg == "md5") {
ctx.arg.build_id.kind = BuildId::HASH;
ctx.arg.build_id.hash_size = 16;
} else if (arg == "sha1") {
ctx.arg.build_id.kind = BuildId::HASH;
ctx.arg.build_id.hash_size = 20;
} else if (arg == "sha256") {
ctx.arg.build_id.kind = BuildId::HASH;
ctx.arg.build_id.hash_size = 32;
} else if (arg.starts_with("0x") || arg.starts_with("0X")) {
ctx.arg.build_id.kind = BuildId::HEX;
ctx.arg.build_id.value = parse_hex_build_id(ctx, arg);
} else {
Fatal(ctx) << "invalid --build-id argument: " << arg;
}
} else if (read_flag(args, "no-build-id")) {
ctx.arg.build_id.kind = BuildId::NONE;
} else if (read_arg(ctx, args, arg, "auxiliary") ||
read_arg(ctx, args, arg, "f")) {
ctx.arg.auxiliary.push_back(arg);
} else if (read_arg(ctx, args, arg, "filter") ||
read_arg(ctx, args, arg, "F")) {
ctx.arg.filter.push_back(arg);
} else if (read_flag(args, "preload")) {
ctx.arg.preload = true;
} else if (read_arg(ctx, args, arg, "O")) {
} else if (read_flag(args, "O0")) {
} else if (read_flag(args, "O1")) {
} else if (read_flag(args, "O2")) {
} else if (read_flag(args, "verbose")) {
} else if (read_arg(ctx, args, arg, "plugin")) {
} else if (read_arg(ctx, args, arg, "plugin-opt")) {
} else if (read_flag(args, "color-diagnostics")) {
} else if (read_flag(args, "gdb-index")) {
} else if (read_arg(ctx, args, arg, "m")) {
} else if (read_flag(args, "eh-frame-hdr")) {
} else if (read_flag(args, "start-group")) {
} else if (read_flag(args, "end-group")) {
} else if (read_flag(args, "(")) {
} else if (read_flag(args, ")")) {
} else if (read_flag(args, "fatal-warnings")) {
} else if (read_flag(args, "enable-new-dtags")) {
} else if (read_flag(args, "disable-new-dtags")) {
} else if (read_flag(args, "nostdlib")) {
} else if (read_flag(args, "allow-shlib-undefined")) {
} else if (read_flag(args, "no-allow-shlib-undefined")) {
} else if (read_flag(args, "no-add-needed")) {
} else if (read_flag(args, "no-copy-dt-needed-entries")) {
} else if (read_flag(args, "no-undefined-version")) {
} else if (read_arg(ctx, args, arg, "sort-section")) {
} else if (read_flag(args, "sort-common")) {
} else if (read_flag(args, "warn-once")) {
} else if (read_flag(args, "nodefaultlibs")) {
} else if (read_flag(args, "warn-constructors")) {
} else if (read_arg(ctx, args, arg, "rpath-link")) {
} else if (read_z_flag(args, "combreloc")) {
} else if (read_z_flag(args, "nocombreloc")) {
} else if (read_arg(ctx, args, arg, "version-script")) {
remaining.push_back("--version-script");
remaining.push_back(arg);
} else if (read_arg(ctx, args, arg, "dynamic-list")) {
remaining.push_back("--dynamic-list");
remaining.push_back(arg);
} else if (read_flag(args, "as-needed")) {
remaining.push_back("-as-needed");
} else if (read_flag(args, "no-as-needed")) {
remaining.push_back("-no-as-needed");
} else if (read_flag(args, "whole-archive")) {
remaining.push_back("-whole-archive");
} else if (read_flag(args, "no-whole-archive")) {
remaining.push_back("-no-whole-archive");
} else if (read_arg(ctx, args, arg, "l")) {
remaining.push_back("-l");
remaining.push_back(arg);
} else if (read_arg(ctx, args, arg, "script") ||
read_arg(ctx, args, arg, "T")) {
remaining.push_back(arg);
} else if (read_flag(args, "push-state")) {
remaining.push_back("-push-state");
} else if (read_flag(args, "pop-state")) {
remaining.push_back("-pop-state");
} else {
if (args[0] == "-z" && args.size() >= 2)
Fatal(ctx) << "mold: unknown command line option: -z " << args[1];
if (args[0][0] == '-')
Fatal(ctx) << "mold: unknown command line option: " << args[0];
remaining.push_back(args[0]);
args = args.subspan(1);
}
}
if (ctx.arg.shared) {
ctx.arg.pic = true;
ctx.arg.dynamic_linker = "";
}
if (ctx.arg.pic)
ctx.arg.image_base = 0;
if (ctx.arg.retain_symbols_file) {
ctx.arg.strip_all = false;
ctx.arg.discard_all = false;
}
if (ctx.arg.relocatable)
ctx.arg.is_static = true;
if (!ctx.arg.shared) {
if (!ctx.arg.filter.empty())
Fatal(ctx) << "-filter may not be used without -shared";
if (!ctx.arg.auxiliary.empty())
Fatal(ctx) << "-auxiliary may not be used without -shared";
}
if (char *env = getenv("MOLD_REPRO"); env && env[0])
ctx.arg.repro = true;
if (ctx.arg.output.empty())
ctx.arg.output = "a.out";
if (version_shown && remaining.empty())
exit(0);
}
#define INSTANTIATE(E) \
template \
std::vector<std::string_view> \
expand_response_files(Context<E> &ctx, char **argv); \
\
template \
bool read_arg(Context<E> &ctx, std::span<std::string_view> &args, \
std::string_view &arg, \
std::string name); \
\
template std::string create_response_file(Context<E> &ctx); \
\
template \
void parse_nonpositional_args(Context<E> &ctx, \
std::vector<std::string_view> &remaining)
INSTANTIATE(X86_64);
INSTANTIATE(I386);
+110
View File
@@ -0,0 +1,110 @@
// This file implements a multi-threaded zlib compression routine.
//
// Multiple pieces of raw compressed data in zlib-format can be merged
// just by concatenation as long as each zlib stream is flushed with
// Z_SYNC_FLUSH. In this file, we split input data into multiple
// shards, compress them individually and concatenate them. We then
// append a header, a trailer and a checksum so that the concatenated
// data is valid zlib-format data.
//
// Using threads to compress data has a downside. Since the dictionary
// is reset on boundaries of shards, compression ratio is sacrificed
// a little bit. However, if a shard size is large enough, that loss
// is negligible in practice.
#include "mold.h"
#include <tbb/parallel_for_each.h>
#include <zlib.h>
static constexpr i64 SHARD_SIZE = 1024 * 1024;
static std::vector<std::string_view> split(std::string_view input) {
std::vector<std::string_view> shards;
while (input.size() >= SHARD_SIZE) {
shards.push_back(input.substr(0, SHARD_SIZE));
input = input.substr(SHARD_SIZE);
}
if (!input.empty())
shards.push_back(input);
return shards;
}
static std::vector<u8> do_compress(std::string_view input) {
// Initialize zlib stream. Since debug info is generally compressed
// pretty well, we chose compression level 3.
z_stream strm;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
int r = deflateInit2(&strm, 3, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY);
assert(r == Z_OK);
// Set an input buffer
strm.avail_in = input.size();
strm.next_in = (u8 *)input.data();
// Set an output buffer. deflateBound() returns an upper bound
// on the compression size. +16 for Z_SYNC_FLUSH.
std::vector<u8> buf(deflateBound(&strm, strm.avail_in) + 16);
strm.avail_out = buf.size();
strm.next_out = buf.data();
r = deflate(&strm, Z_SYNC_FLUSH);
assert(r == Z_OK);
assert(strm.avail_out > 0);
buf.resize(buf.size() - strm.avail_out);
deflateEnd(&strm);
return buf;
}
Compressor::Compressor(std::string_view input) {
std::vector<std::string_view> inputs = split(input);
std::vector<u64> adlers(inputs.size());
shards.resize(inputs.size());
// Compress each shard
tbb::parallel_for((i64)0, (i64)inputs.size(), [&](i64 i) {
adlers[i] = adler32(1, (u8 *)inputs[i].data(), inputs[i].size());
shards[i] = do_compress(inputs[i]);
});
// Combine checksums
checksum = adlers[0];
for (i64 i = 1; i < inputs.size(); i++)
checksum = adler32_combine(checksum, adlers[i], inputs[i].size());
}
i64 Compressor::size() const {
i64 size = 2; // +2 for header
for (const std::vector<u8> &shard : shards)
size += shard.size();
return size + 6; // +6 for trailer and checksum
}
void Compressor::write_to(u8 *buf) {
// Write a zlib-format header
buf[0] = 0x78;
buf[1] = 0x9c;
// Copy compressed data
std::vector<i64> offsets(shards.size());
offsets[0] = 2; // +2 for header
for (i64 i = 1; i < shards.size(); i++)
offsets[i] = offsets[i - 1] + shards[i - 1].size();
tbb::parallel_for((i64)0, (i64)shards.size(), [&](i64 i) {
memcpy(&buf[offsets[i]], shards[i].data(), shards[i].size());
});
// Write a trailer
u8 *end = buf + size();
end[-6] = 3;
end[-5] = 0;
// Write a checksum
write32be(end - 4, checksum);
}
-247
View File
@@ -1,247 +0,0 @@
#!/bin/bash
#
# This script creates a mold binary distribution. The output is written to
# the `dist` directory as `mold-$version-$arch-linux.tar.gz` (e.g.
# `mold-2.40.0-x86_64-linux.tar.gz`).
#
# This script aims to produce reproducible outputs. That means each time
# it's run on the same git commit, it generates a bit-for-bit identical
# binary file regardless of when or where it's executed. This property
# serves as a strong safeguard against supply chain attacks. With a
# reproducible build, anyone can independently verify that the binary
# files published on our GitHub release page were built from the git
# commit tagged for release by rebuilding the binaries themselves.
#
# Debian provides snapshot.debian.org to host all historical binary
# packages. We use it to construct a container image pinned to a
# particular timestamp. snapshot.debian.org is known to be very slow,
# but that shouldn't be a big problem for us because we only need that
# site the first time.
#
# The mold executable created by this script is statically linked to
# libstdc++, but dynamically linked to glibc, libm and a few other
# libraries, as these libraries are almost always available on any Linux
# system. We can't statically link glibc because doing so would disable
# dlopen(), which is required to load the LTO linker plugin.
#
# We use a reasonably old Debian version for the build environment because
# a binary dynamically linked against a newer version of glibc won't work
# on a system with an older version of glibc.
#
# We prefer to build mold with Clang rather than GCC because mold's
# Identical Code Folding works best with the LLVM address significance
# table (.llvm_addrsig). Building a release binary with GCC produces a
# slightly larger binary than with Clang.
#
# We need a recent version of Clang to build mold. If it's not available
# via apt-get, we'll build it ourselves.
#
# This script can be used to create non-native binaries (e.g., building
# aarch64 binary on x86-64) because Podman automatically runs everything
# under QEMU if the container image is not native. To use this script for
# non-native builds, you may need to install the qemu-user-static package.
set -e -x
cd "$(dirname $0)"
usage() {
echo "Usage: $0 [ x86_64 | aarch64 | arm | riscv64 | ppc64le | s390x | loongarch64 ]"
exit 1
}
case $# in
0)
arch=$(uname -m)
if [ $arch = arm64 ]; then
arch=aarch64
elif [[ $arch = arm* ]]; then
arch=arm
fi
;;
1)
arch="$1"
;;
*)
usage
esac
# Create a Podman image.
if [ "$GITHUB_REPOSITORY" = '' ]; then
image=mold-builder-$arch
image_build="podman build --arch $arch -t $image -"
else
# If this script is running on GitHub Actions, we want to cache
# the created container image in GitHub's container repostiory.
image=ghcr.io/$GITHUB_REPOSITORY/mold-builder-$arch
image_build="podman build --arch $arch -t $image --output=type=registry --layers --cache-to $image --cache-from $image -"
fi
case $arch in
x86_64)
# Debian 9 (Stretch) released in June 2017.
#
# We use a Google-provided mirror (gcr.io) instead of the official Docker
# Hub (docker.io) because docker.io has a strict rate limit policy.
#
# The toolchain in Debian 9 is too old to build mold, so we rebuild it
# from source. We download source archives from official sites and build
# them locally, rather than downloading pre-built binaries from somewhere
# else, to avoid relying on unverifiable third-party binary blobs. Podman
# caches the result of each RUN command, so rebuilding is done only once
# per host.
cat <<EOF | $image_build
FROM mirror.gcr.io/library/debian:stretch@sha256:c5c5200ff1e9c73ffbf188b4a67eb1c91531b644856b4aefe86a58d2f0cb05be
ENV DEBIAN_FRONTEND=noninteractive TZ=UTC
RUN sed -i -e '/^deb/d' -e 's/^# deb /deb /g' /etc/apt/sources.list && \
echo 'Acquire::Retries "10"; Acquire::http::timeout "10"; Acquire::Check-Valid-Until "false";' > /etc/apt/apt.conf.d/80-retries && \
apt-get update && \
apt-get install -y --no-install-recommends wget file make gcc g++ zlib1g-dev libssl-dev ca-certificates && \
rm -rf /var/lib/apt/lists
# Build CMake 3.27
RUN mkdir /build && \
cd /build && \
wget -O- --progress=dot:mega https://cmake.org/files/v3.27/cmake-3.27.7.tar.gz | tar xzf - --strip-components=1 && \
./bootstrap --parallel=\$(nproc) && \
make -j\$(nproc) && \
make install && \
rm -rf /build
# Build GCC 14
RUN mkdir /build && \
cd /build && \
wget -O- --progress=dot:mega https://ftpmirror.gnu.org/gcc/gcc-14.2.0/gcc-14.2.0.tar.gz | tar xzf - --strip-components=1 && \
mkdir gmp mpc mpfr && \
wget -O- --progress=dot:mega https://ftpmirror.gnu.org/gmp/gmp-6.3.0.tar.gz | tar xzf - --strip-components=1 -C gmp && \
wget -O- --progress=dot:mega https://ftpmirror.gnu.org/mpc/mpc-1.3.1.tar.gz | tar xzf - --strip-components=1 -C mpc && \
wget -O- --progress=dot:mega https://ftpmirror.gnu.org/mpfr/mpfr-4.2.1.tar.gz | tar xzf - --strip-components=1 -C mpfr && \
./configure --prefix=/usr --enable-languages=c,c++ --disable-bootstrap --disable-multilib && \
make -j\$(nproc) && \
make install && \
ln -sf /usr/lib64/libstdc++.so.6 /usr/lib/x86_64-linux-gnu/libstdc++.so.6 && \
rm -rf /build
# Build GNU binutils 2.43
RUN mkdir /build && \
cd /build && \
wget -O- --progress=dot:mega https://ftpmirror.gnu.org/binutils/binutils-2.43.tar.gz | tar xzf - --strip-components=1 && \
./configure --prefix=/usr && \
make -j\$(nproc) && \
make install && \
rm -fr /build
# Build Python 3.12.7
RUN mkdir /build && \
cd /build && \
wget -O- --progress=dot:mega https://www.python.org/ftp/python/3.12.7/Python-3.12.7.tgz | tar xzf - --strip-components=1 && \
./configure && \
make -j\$(nproc) && \
make install && \
rm -rf /build
# Build LLVM 20
RUN mkdir /build && \
cd /build && \
wget -O- --progress=dot:mega https://github.com/llvm/llvm-project/archive/refs/tags/llvmorg-20.1.3.tar.gz | tar xzf - --strip-components=1 && \
mkdir b && \
cd b && \
cmake -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS=clang ../llvm && \
cmake --build . -j\$(nproc) && \
cmake --install . --strip && \
rm -rf /build
EOF
;;
aarch64 | arm | ppc64le | s390x)
# Debian 11 (Bullseye) released in August 2021
#
# We don't want to build Clang for these targets on QEMU becuase it
# would take an extremely long time. Also, I believe old Linux boxes
# are typically x86-64.
cat <<EOF | $image_build
FROM mirror.gcr.io/library/debian:bullseye-20240904@sha256:8ccc486c29a3ad02ad5af7f1156e2152dff3ba5634eec9be375269ef123457d8
ENV DEBIAN_FRONTEND=noninteractive TZ=UTC
RUN sed -i -e '/^deb/d' -e 's/^# deb /deb /g' /etc/apt/sources.list && \
echo 'Acquire::Retries "10"; Acquire::http::timeout "10"; Acquire::Check-Valid-Until "false";' > /etc/apt/apt.conf.d/80-retries && \
apt-get update && \
apt-get install -y --no-install-recommends build-essential gcc-10 g++-10 clang-16 cmake && \
ln -sf /usr/bin/clang-16 /usr/bin/clang && \
ln -sf /usr/bin/clang++-16 /usr/bin/clang++ && \
rm -rf /var/lib/apt/lists
EOF
;;
riscv64)
cat <<EOF | $image_build
FROM mirror.gcr.io/riscv64/debian:unstable-20240926@sha256:25654919c2926f38952cdd14b3300d83d13f2d820715f78c9f4b7a1d9399bf48
ENV DEBIAN_FRONTEND=noninteractive TZ=UTC
RUN sed -i -e '/^URIs/d' -e 's/^# http/URIs: http/' /etc/apt/sources.list.d/debian.sources && \
echo 'Acquire::Retries "10"; Acquire::http::timeout "10"; Acquire::Check-Valid-Until "false";' > /etc/apt/apt.conf.d/80-retries && \
apt-get update && \
apt-get install -y --no-install-recommends build-essential gcc-14 g++-14 clang-18 cmake && \
ln -sf /usr/bin/clang-18 /usr/bin/clang && \
ln -sf /usr/bin/clang++-18 /usr/bin/clang++ && \
rm -rf /var/lib/apt/lists
EOF
;;
loongarch64)
cat <<EOF | $image_build
FROM mirror.gcr.io/loongarch64/debian:sid@sha256:0356df4e494bbb86bb469377a00789a5b42bbf67d5ff649a3f9721b745cbef77
ENV DEBIAN_FRONTEND=noninteractive TZ=UTC
RUN sed -i -e 's!http[^ ]*!http://snapshot.debian.org/archive/debian-ports/20250620T014755Z!g' /etc/apt/sources.list && \
echo 'Acquire::Retries "10"; Acquire::http::timeout "10"; Acquire::Check-Valid-Until "false";' > /etc/apt/apt.conf.d/80-retries && \
apt-get update && \
apt-get install -y --no-install-recommends build-essential gcc-14 g++-14 clang-19 cmake && \
ln -sf /usr/bin/clang-19 /usr/bin/clang && \
ln -sf /usr/bin/clang++-19 /usr/bin/clang++ && \
rm -rf /var/lib/apt/lists
EOF
;;
*)
usage
;;
esac
version=$(sed -n 's/^project(mold VERSION \(.*\))/\1/p' CMakeLists.txt)
dest=mold-$version-$arch-linux
# Source tarballs available on GitHub don't contain .git directory.
# Clone the repo if missing.
[ -d .git ] || git clone --branch v$version --depth 1 --bare https://github.com/rui314/mold .git
# We use the timestamp of the last Git commit as the file timestamp
# for build artifacts.
timestamp=$(git log -1 --format=%ct)
# `uname -m` in an ARM32 container running on an ARM64 host reports it
# not as ARM32 but as ARM64. That confuses BLAKE3's cmake script and
# erroneously enables NEON SIMD instructions. `setarch` can be used to
# change the output of `uname -m`.
setarch=
[ $arch = arm ] && setarch='setarch linux32'
mkdir -p dist
# Build mold in a container.
#
# SOURCE_DATE_EPOCH is a standardized environment variable that allows
# build artifacts to appear as if they were built at a specific time.
# We use it to control how the compiler expands the C/C++ __DATE__ and
# __TIME__ macros.
podman run --arch $arch -it --rm --userns=host --pids-limit=-1 --network=none \
--pull=never -v "$(pwd):/mold:ro" -v "$(pwd)/dist:/dist" $image \
$setarch bash -c "
set -e
export SOURCE_DATE_EPOCH=$timestamp
mkdir /build
cd /build
cmake -DCMAKE_BUILD_TYPE=Release -DMOLD_MOSTLY_STATIC=1 -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ /mold
cmake --build . -j\$(nproc)
cmake --install .
cmake -DMOLD_USE_MOLD=1 .
cmake --build . -j\$(nproc)
ctest --output-on-failure -j\$(nproc)
cmake --install . --prefix $dest --strip
find $dest -print | xargs touch --no-dereference --date=@$timestamp
find $dest -print | sort | tar -cf - --no-recursion --files-from=- | gzip -9nc > /dist/$dest.tar.gz
cp mold /dist
sha256sum /dist/$dest.tar.gz
"
+2 -2
View File
@@ -31,7 +31,7 @@ If a program is statically-linked, there's no dynamic loader that
rewrites the GOT entries. Therefore, if a program is
statically-linked, a libc's startup routine does that on behalf of the
dynamic loader. Concretely, a startup routine interprets all dynamic
relocations between `__rela_iplt_start` and `__rela_iplt_stop`
relocations between `__rela_iplt_start` and `__rela_iplt_start`
symbols. It is linker's responsibility to emit dynamic relocations
for IFUNC symbols even if it is linking a statically-linked program
and mark the beginning and the ending of a `.rela.dyn` section with
@@ -41,7 +41,7 @@ The bug was my linker didn't define `__rela_iplt_start` and
`__rela_iplt_stop` symbols. Since these symbols are weak, they are
initialized to zero. From the point of the initializer function,
there's no dynamic relocations between `__rela_iplt_start` and
`__rela_iplt_stop` symbols. That left GOT entries for IFUNC symbols
`__rela_iplt_start` symbols. That left GOT entries for IFUNC symbols
untouched.
The proper fix was to emit dynamic relocations for IFUNC symbols and
-1
View File
@@ -1 +0,0 @@
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@@ -1,46 +0,0 @@
# Coding Guidelines
mold is written in C++20, but as is the case with every C++ project,
it has local coding rules. In this document, I'll explain some of them
and try to give justifications for why I chose such rules.
## DOs
- Always use `i64` (which is a type alias for `int64_t` in mold) for
integers unless you have a reason not to. For example, even if you know
that a loop counter won't exceed 100, you should stop thinking about it
and just use `i64`.
Justification: Local variables are usually on CPU registers, so on
64-bit CPUs, there's no performance peanlty on choosing `i64` over
`i32`. Even if a compiler has to spill register values to the stack,
I don't think there's an observable difference between `i32` and
`i64`. Therefore, extra 32 bits are essentially free. On 32-bit CPUs,
they are not free, but that's OK because we are writing mold for modern
computers. mold will still run on 32-bit computers but a bit slowly.
By always using `i64`, we can eliminate the need to think about the
"right" size for each variable. It also reduces the risk of integer
overflow.
Exceptions: If you have to allocate a very large number (e.g. millions)
of the same object, its size matters. In that case, use a smaller type.
## DON'Ts
- Don't use `auto` unless its actual type is obvious in the very narrow
context. Currently, we use `auto` only for lambdas.
Justification: I think `auto` makes code writing easier but code reading
harder, because readers have to make a guess as to what is the actual
type of `auto`. If you are already familiar with the existing codebase,
you may be able to guess it easily, but that's not always the case.
I want to keep the mold codebase friendly to first-time readers.
- Don't over-use inheritance. In mold, most classes don't have parents,
and even if they do, their class hierarchy is very shallow. Currently
its height is just two (i.e. abstract classes and their implementations).
Justification: Designing class hierarchies is fun as it feels like
taxonomy, but I don't think that always help writing code. It looks like
simpler class hierarchy makes its code simpler.
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-491
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@@ -1,491 +0,0 @@
[This document was written in 2020, and the contents are outdated.
Specifically, we no longer believe that object preloading is a good
idea. That being said, most of the points in this document still hold
even today. Therefore, I'll keep this document as-is.]
## Design and implementation of mold
For the rest of this documentation, I'll explain the design and the
implementation of mold. If you are only interested in using mold, you
don't need to read the below.
### Motivation
Here is why I'm writing a new linker:
- Even though lld has significantly improved the situation, linking is
still one of the slowest steps in a build. It is especially
annoying when I changed one line of code and had to wait for a few
seconds or even more for a linker to complete. It should be
instantaneous. There's a need for a faster linker.
- The number of cores on a PC has increased a lot lately, and this
trend is expected to continue. However, the existing linkers can't
take the advantage of the trend because they don't scale well for more
cores. I have a 64-core/128-thread machine, so my goal is to create
a linker that uses the CPU nicely. mold should be much faster than
other linkers on 4 or 8-core machines too, though.
- It looks to me that the designs of the existing linkers are somewhat
too similar, and I believe there are a lot of drastically different
designs that haven't been explored yet. Developers generally don't
care about linkers as long as they work correctly, and they don't
even think about creating a new one. So there may be lots of low
hanging fruits there in this area.
### Basic design
- In order to achieve a `cp`-like performance, the most important
thing is to fix the layout of an output file as quickly as possible, so
that we can start copying actual data from input object files to an
output file as soon as possible.
- Copying data from input files to an output file is I/O-bounded, so
there should be room for doing computationally-intensive tasks while
copying data from one file to another.
- We should allow the linker to preload object files from disk and
parse them in memory before a complete set of input object files
is ready. To do so, we need
to split the linker into two in such a way that the latter half of
the process finishes as quickly as possible by speculatively parsing
and preprocessing input files in the first half of the process.
- One of the most computationally-intensive stage among linker stages
is symbol resolution. To resolve symbols, we basically have to throw
all symbol strings into a hash table to match undefined symbols with
defined symbols. But this can be done in the preloading stage using
[string interning](https://en.wikipedia.org/wiki/String_interning).
- Object files may contain a special section called a mergeable string
section. The section contains lots of null-terminated strings, and
the linker is expected to gather all mergeable string sections and
merge their contents. So, if two object files contain the same
string literal, for example, the resulting output will contain a
single merged string. This step is computationally intensive, but string
merging can be done in the preloading stage using string interning.
- Static archives (.a files) contain object files, but the static
archive's string table contains only defined symbols of member
object files and lacks other types of symbols. That makes static
archives unsuitable for speculative parsing. Therefore, the linker
should ignore the symbol table of static archive and directly read
static archive members.
- If there's a relocation that uses a GOT of a symbol, then we have to
create a GOT entry for that symbol. Otherwise, we shouldn't. That
means we need to scan all relocation tables to fix the length and
the contents of a .got section. This is computationally intensive,
but this step is parallelizable.
### Linker Script
Linker script is an embedded language for the linker. It is mainly
used to control how input sections are mapped to output sections and
the layout of the output, but it can also do a lot of tricky stuff.
Its feature is useful especially for embedded programming, but it's
also an awfully underdocumented and complex language.
We have to implement a subset of the linker script language anwyay,
because on Linux, /usr/lib/x86_64-linux-gnu/libc.so is (despite its
name) not a shared object file but actually an ASCII file containing
linker script code to load the _actual_ libc.so file. But the feature
set for this purpose is very limited, and it is okay to implement them
to mold.
Besides that, we really don't want to implement the linker script
language. But at the same time, we want to satisfy the user needs that
are currently satisfied with the linker script language. So, what
should we do? Here is my observation:
- Linker script allows doing a lot of tricky stuff, such as specifying
the exact layout of a file, inserting arbitrary bytes between
sections, etc. But most of them can be done with a post-link binary
editing tool (such as `objcopy`).
- It looks like there are two things that truly cannot be done by a
post-link editing tool: (a) mapping input sections to output
sections, and (b) applying relocations.
From the above observation, I believe we need to provide only the
following features instead of the entire linker script language:
- A method to specify how input sections are mapped to output
sections, and
- a method to set addresses to output sections, so that relocations
are applied based on desired addresses.
I believe everything else can be done with a post-link binary editing
tool.
### Details
- As we aim to the 1-second goal for Chromium, every millisecond
counts. We can't ignore the latency of process exit. If we mmap a
lot of files, \_exit(2) is not instantaneous but takes a few hundred
milliseconds because the kernel has to clean up a lot of
resources. As a workaround, we should organize the linker command as
two processes; the first process forks the second process, and the
second process does the actual work. As soon as the second process
writes a result file to a filesystem, it notifies the first process,
and the first process exits. The second process can take time to
exit, because it is not an interactive process.
- At least on Linux, it looks like the filesystem's performance to
allocate new blocks to a new file is the limiting factor when
creating a new large file and filling its contents using mmap.
If you already have a large file in the buffer cache, writing to it is
much faster than creating a new fresh file and writing to it.
Based on this observation, mold overwrites to an existing
executable file if exists. My quick benchmark showed that I could
save 300 milliseconds when creating a 2 GiB output file.
Linux doesn't allow to open an executable for writing if it is
running (you'll get a "text busy" error if you attempt). mold
falls back to the usual way if it fails to open an output file.
- The output from the linker should be deterministic for the sake of
[build reproducibility](https://en.wikipedia.org/wiki/Reproducible_builds)
and ease of debugging. This might add a little bit of overhead to
the linker, but that shouldn't be too much.
- A .build-id, a unique ID embedded to an output file, is usually
computed by applying a cryptographic hash function (e.g. SHA-1) to
an output file. This is a slow step, but we can speed it up by
splitting a file into small chunks, computing SHA-1 for each chunk,
and then computing SHA-1 of the concatenated SHA-1 hashes
(i.e. constructing a [Merkle
Tree](https://en.wikipedia.org/wiki/Merkle_tree) of height 2).
Modern x86 processors have purpose-built instructions for SHA-1 and
can compute SHA-1 pretty quickly at about 2 GiB/s. Using 16
cores, a build-id for a 2 GiB executable can be computed in 60 to 70
milliseconds.
- BFD, gold, and lld support section garbage collection. That is, a
linker runs a mark-sweep garbage collection on an input graph, where
sections are vertices and relocations are edges, to discard all
sections that are not reachable from the entry point symbol
(i.e. `_start`) or a few other root sections. In mold, we are using
multiple threads to mark sections concurrently.
- Similarly, BFD, gold an lld support Identical Comdat Folding (ICF)
as yet another size optimization. ICF merges two or more read-only
sections that happen to have the same contents and relocations.
To do that, we have to find isomorphic subgraphs from larger graphs.
I implemented a new algorithm for mold, which is 5x faster than lld
to do ICF for Chromium (from 5 seconds to 1 second).
- [Intel Threading Building
Blocks](https://github.com/oneapi-src/oneTBB) (TBB) is a good
library for parallel execution and has several concurrent
containers. We are particularly interested in using
`parallel_for_each` and `concurrent_hash_map`.
- TBB provides `tbbmalloc` which works better for multi-threaded
applications than the glib'c malloc, but it looks like
[jemalloc](https://github.com/jemalloc/jemalloc) and
[mimalloc](https://github.com/microsoft/mimalloc) are a little bit
more scalable than `tbbmalloc`.
### Size of the problem
When linking Chrome, a linker reads 3,430,966,844 bytes of data in
total. The data contains the following items:
| Data item | Number
| ------------------------ | ------
| Object files | 30,723
| Public undefined symbols | 1,428,149
| Mergeable strings | 1,579,996
| Comdat groups | 9,914,510
| Regular sections¹ | 10,345,314
| Public defined symbols | 10,512,135
| Symbols | 23,953,607
| Sections | 27,543,225
| Relocations against SHF_ALLOC sections | 39,496,375
| Relocations | 62,024,719
¹ Sections that have to be copied from input object files to an
output file. Sections that contain relocations or symbols are for
example excluded.
### Internals
In this section, I'll explain the internals of mold linker.
#### A brief history of Unix and the Unix linker
Conceptually, what a linker does is pretty simple. A compiler compiles
a fragment of a program (a single source file) into a fragment of
machine code and data (an object file, which typically has the .o
extension), and a linker stitches them together into a single
executable or a shared library image.
In reality, modern linkers for Unix-like systems are much more
complicated than the naive understanding because they have gradually
gained one feature at a time over the 50 years history of Unix, and
they are now something like a bag of lots of miscellaneous features in
which none of the features is more important than the others. It is
very easy to miss the forest for the trees, since for those who don't
know the details of the Unix linker, it is not clear which feature is
essential and which is not.
That being said, one thing is clear that at any point of Unix history,
a Unix linker has a coherent feature set for the Unix of that age. So,
let me entangle the history to see how the operating system, runtime,
and linker have gained features that we see today. That should give
you an idea of why a particular feature has been added to a linker in the
first place.
1. Original Unix didn't support shared libraries, and a program was
always loaded to a fixed address. An executable was something like
a memory dump that was just loaded to a particular address by the
kernel. After loading, the kernel started executing the program by
setting the instruction pointer to a particular address.
The most essential feature for any linker is relocation processing.
The original Unix linker of course supported that. Let me explain
what that is.
Individual object files are inevitably incomplete as a program,
because when a compiler created them, it only see a part of an
entire program. For example, if an object file contains a function
call that refers to another object file, the `call` instruction in the
object cannot be complete, as the compiler has no idea as to what
is the called function's address. To deal with this, the compiler
emits a placeholder value (typically just zero) instead of a real
address and leaves metadata in an object file saying "fix offset X
of this file with an address of Y". That metadata is called
"relocation". Relocations are typically processed by the linker.
It is easy for a linker to apply relocations for the original Unix
because a program is always loaded to a fixed address. It exactly
knows the addresses of all functions and data when linking a
program.
Static library support, which is still an important feature of Unix
linker, also dates back to this early period of Unix history.
To understand what it is, imagine that you are trying to compile
a program for the early Unix. You don't want to waste time to
compile libc functions every time you compile your program (the
computers of the era were incredibly slow), so you have already
placed each libc function into a separate source file and compiled
them individually. That means you have object files for each libc
function, e.g., printf.o, scanf.o, atoi.o, write.o, etc.
Given this configuration, all you have to do to link your program
against libc functions is to pick up the right set of libc object
files and give them to the linker along with the object files of your
program. But, keeping the linker command line in sync with the
libc functions you are using in your program is bothersome. You can
be conservative; you can specify all libc object files to the
command line, but that leads to program bloat because the linker
unconditionally link all object files given to it no matter whether
they are used or not. So, a new feature was added to the linker to
fix the problem. That is the static library, which is also called
the archive file.
An archive file is just a bundle of object files, just like zip
file but in an uncompressed form. An archive file typically has the
.a file extension and named after its contents. For example, the
archive file containing all libc objects is named `libc.a`.
If you pass an archive file along with other object files to the
linker, the linker pulls out an object file from the archive _only
when_ it is referenced by other object files. In other words,
unlike object files directly given to a linker, object files
wrapped in an archive are not linked to the output by default.
An archive works as a supplement to complete your program.
Even today, you can still find a libc archive file. Run `ar t
/usr/lib/x86_64-linux-gnu/libc.a` on Linux should give you a list
of object files in the libc archive.
2. In the '80s, Sun Microsystems, a leading commercial Unix vendor at the
time, added shared library support to their Unix variant, SunOS.
(This section is incomplete.)
### Concurrency strategy
In this section, I'll explain the high-level concurrency strategy of
mold.
In most places, mold adopts data parallelism. That is, we have a huge
number of pieces of data of the same kind, and we process each of them
individually using parallel for-loop. For example, after identifying
the exact set of input object files, we need to scan all relocation
tables to determine the sizes of .got and .plt sections. We do that
using a parallel for-loop. The granularity of parallel processing in
this case is the relocation table.
Data parallelism is very efficient and scalable because there's no
need for threads to communicate with each other while working on each
element of data. In addition to that, data parallelism is easy to
understand, as it is just a for-loop in which multiple iterations may
be executed in parallel. We don't use high-level communication or
synchronization mechanisms such as channels, futures, promises,
latches or something like that in mold.
In some cases, we need to share a little bit of data between threads
while executing a parallel for-loop. For example, the loop to scan
relocations turns on "requires GOT" or "requires PLT" flags in a
symbol. Symbol is a shared resource, and writing to them from multiple
threads without synchronization is unsafe. To deal with it, we made
the flag an atomic variable.
The other common pattern you can find in mold which is build on top of
the parallel for-loop is the map-reduce pattern. That is, we run a
parallel for-loop on a large data set to produce a small data set and
process the small data set with a single thread. Let me take a
build-id computation as an example. Build-id is typically computed by
applying a cryptographic hash function such as SHA-1 on a linker's
output file. To compute it, we first consider an output as a sequence
of 1 MiB blocks and compute a SHA-1 hash for each block in parallel.
Then, we concatenate the SHA-1 hashes and compute a SHA-1 hash on the
hashes to get a final build-id.
Finally, we use concurrent hashmap at a few places in mold. Concurrent
hashmap is a hashmap to which multiple threads can safely insert items
in parallel. We use it in the symbol resolution stage, for example.
To resolve symbols, we basically have to throw in all defined symbols
into a hash table, so that we can find a matching defined symbol for
an undefined symbol by name. We do the hash table insertion from a
parallel for-loop which iterates over a list of input files.
Overall, even though mold is highly scalable, it succeeded to avoid
complexties you often find in complex parallel programs. From high
level, mold just serially executes the linker's internal passes one by
one. Each pass is parallelized using parallel for-loops.
### Rejected ideas
In this section, I'll explain the alternative designs I currently do
not plan to implement and why I turned them down.
- Placing variable-length sections at end of an output file and start
copying file contents before fixing the output file layout
Idea: Fixing the layout of regular sections seems easy, and if we
place them at beginning of a file, we can start copying their
contents from their input files to an output file. While copying
file contents, we can compute the sizes of variable-length sections
such as .got or .plt and place them at end of the file.
Reason for rejection: I did not choose this design because I doubt
if it could actually shorten link time and I think I don't need it
anyway.
The linker has to de-duplicate comdat sections (i.e. inline
functions that are included in multiple object files), so we
cannot compute the layout of regular sections until we resolve all
symbols and de-duplicate comdats. That takes a few hundred
milliseconds. After that, we can compute the sizes of
variable-length sections in less than 100 milliseconds. It's quite
fast, so it doesn't seem to make much sense to proceed without
fixing the final file layout.
The other reason to reject this idea is because there's good a
chance for this idea to have a negative impact on linker's overall
performance. If we copy file contents before fixing the layout, we
can't apply relocations to them while copying because symbol
addresses are not available yet. If we fix the file layout first, we
can apply relocations while copying, which is effectively zero-cost
due to a very good data locality. On the other hand, if we apply
relocations long after we copy file contents, it's pretty expensive
because section contents are very likely to have been evicted from
CPU cache.
- Incremental linking
Idea: Incremental linking is a technique to patch a previous linker's
output file so that only functions or data that are updated from the
previous build are written to it. It is expected to significantly
reduce the amount of data copied from input files to an output file
and thus speed up linking. GNU BFD and gold linkers support it.
Reason for rejection: I turned it down because it (1) is
complicated, (2) doesn't seem to speed it up that much and (3) has
several practical issues. Let me explain each of them.
First, incremental linking for real C/C++ programs is not as easy as
one might think. Let me take malloc as an example. malloc is usually
defined by libc, but you can implement it in your program, and if
that's the case, the symbol `malloc` will be resolved to your
function instead of the one in libc. If you include a library that
defines malloc (such as libjemalloc or libtbbmallc) before libc,
their malloc will override libc's malloc.
Assume that you are using a nonstandard malloc. What if you remove
your malloc from your code, or remove `-ljemalloc` from your
Makefile? The linker has to include a malloc from libc, which may
include more object files to satisfy its dependencies. Such code
change can affect the entire program rather than just replacing one
function. The same is true for adding malloc to your program. Making
a local change doesn't necessarily result in a local change in the
binary level. It can easily have cascading effects.
Some ELF fancy features make incremental linking even harder to
implement. Take the weak symbol as an example. If you define `atoi`
as a weak symbol in your program, and if you are not using `atoi`
at all in your program, that symbol will be resolved to address
0. But if you start using some libc function that indirectly calls
`atoi`, then `atoi` will be included in your program, and your weak
symbol will be resolved to that function. I don't know how to
efficiently fix up a binary for this case.
This is a hard problem, so existing linkers don't try too hard to
solve it. For example, IIRC, gold falls back to full link if any
function is removed from a previous build. If you want to not annoy
users in the fallback case, you need to make full link fast anyway.
Second, incremental linking itself has an overhead. It has to detect
updated files, patch an existing output file and write additional
data to an output file for future incremental linking. GNU gold, for
instance, takes almost 30 seconds on my machine to do a null
incremental link (i.e. no object files are updated from a previous
build) for chrome. It's just too slow.
Third, there are other practical issues in incremental linking. It's
not reproducible, so your binary isn't going to be the same as other
binaries even if you are compiling the same source tree using the
same compiler toolchain. Or, it is complex and there might be a bug
in it. If something doesn't work correctly, "remove --incremental
from your Makefile and try again" could be a piece of advice, but
that isn't ideal.
So, all in all, incremental linking is tricky. I wanted to make full
link as fast as possible, so that we don't have to think about how
to work around the slowness of full link.
- Defining a completely new file format and use it
Idea: Sometimes, the ELF file format itself seems to be a limiting
factor in improving the linker's performance. We might be able to make a
far better one if we create a new file format.
Reason for rejection: I rejected the idea because it apparently has
a practical issue (backward compatibility issue) and also doesn't
seem to improve the performance of linkers that much. As clearly
demonstrated by mold, we can create a fast linker for ELF. I believe
ELF isn't that bad, after all. The semantics of the existing Unix
linkers, such as the name resolution algorithm or the linker script,
have slowed the linkers down, but that's not a problem of the file
format itself.
- Watching object files using inotify(2)
Idea: When mold is running as a daemon for preloading, use
inotify(2) to watch file system updates so that it can reload files
as soon as they are updated.
Reason for rejection: Just like the maximum number of files you can
simultaneously open, the maximum number of files you can watch using
inotify(2) isn't that large. Maybe just a single instance of mold is
fine with inotify(2), but it may fail if you run multiple of it.
The other reason for not doing it is because mold is quite fast
without it anyway. Invoking stat(2) on each file for file update
check takes less than 100 milliseconds for Chrome, and if most of
the input files are not updated, parsing updated files takes almost
no time.
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This page explains the following warning message and how to fix it.
mold emits this message when it sees an object file that may not be
compatible with mold.
```
mold: warning: foo.o: this file may cause a segmentation fault because it requires an executable stack. See https://github.com/rui314/mold/tree/main/docs/execstack.md for more info.
```
# Background
On modern computers, the stack area (to which local variables are
stored) cannot contain executable code. If the control reaches the
stack area, the CPU refuses to execute any code there and the program
is usually terminated due to segmentation fault.
This is a security measure. The stack area used to be executable (old
CPUs generally execute any code as long as it is in a readable memory
region), but that provided an easy attack vector to a malicious user.
They wrote executable code to the stack area using some buffer
overflow bug and jumped there to run arbitrary code in a remote server
process.
To prevent this type of attack, the stack area is no longer executable
since the early 2000s. On Linux, the stack's executable-ness is
controlled by a bit in an executable, and the loader respects that
bit. The bit is set by the linker.
GCC had (and still has) a feature that depends on the executable
stack, so they invented a way to tell the linker to mark the stack
executable. Specifically, if an object file contains a
`.note.GNU-stack` section with the `SHF_EXECSTACK` bit, GNU linker
silently makes the stack of an output file executable.
But the GNU linker's behavior is dangerous. If you accidentally link
an object file that has that marker section, the entire stack area
silently becomes executable, disabling the security mechanism.
Therefore, mold simply ignores that marker section. If you are using
mold, you need to explicitly pass `-z execstack` to the linker to make
the stack executable.
# What caused this issue?
You are likely to use GCC's [Nested
Functions](https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html)
feature which still depends on the executable stack.
# How to fix it?
If you know what you are doing, pass `-z execstack` to mold. Beware
that this will significantly weaken your program's security.
If you don't want to pass `-z execstack`, rewrite your code so that
your code does not depend on the executable stack.
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The very concept of linking is simple: a compiler compiles a piece of
source code into an object file (a file containing machine code), and
a linker combines object files into a single executable or a shared
library file. However, the actual implementation of the linker for
modern systems is much more complicated because hardware, operating
system, compiler and linker all have many more features.
In this file, I'll explain random topics in the glossary format that
you need to understand to read mold code.
## DSO
A .so file. Short for Dynamic Shared Object. Often called as a
shared library, a dynamic libray or a shared object as well.
An DSO contains common functions and data that are used by multiple
executables and/or other DSOs. At runtime, a DSO is loaded to a
contiguous region in the virtual address.
## Object file
A .o file. An object file contains machine code and data, but it
cannot be executed because it's not self-contained. For example,
if you compile a C source file containing a call of `printf`,
the actual function code of `printf` is not included in the resulting
object file. You include `stdio.h`, but that teaches the compiler
only about `printf`'s type, and the compiler still don't know what
`printf` actually does. Therefore, it cannot emit code for `printf`.
You need to link an object file with other object file or a shared
library to make it exectuable.
## Virtual address space
A pointer has a value like 0x803020 which is an address of the
pointee. But it doesn't mean that the pointee resides at the
physical memory address 0x803020 on the computer. Modern CPUs
contains so-called Mmeory Management Unit (MMU), and all access to
the memory are first translated by MMU to the physical address.
The address before translation is called the "virtual address".
Unless you are doing the kernel programming, all addresses you
handle are virtual addresses.
The OS kernel controls the MMU so that each process owns the entire
virtual address space. So, even if two process uses the same virtual
address, they don't conflict. They are mapped to different physical
addresses.
The existence of MMU has several implications to the linker. First,
we can link the main executable to a specific address. On process
startup, there's no code or data in the virtual address space, so
the mapping of the main executable always succeed. However, it's not
true to DSOs because they are loaded after the main executable and
possibly other DSOs. Therefore, shared libraries must be linked in a
way that they can be loaded to any address in the virtual address
space.
## Relocation
A piece of information for the linker as to how to link object files
or a dynamic objects.
Object files can refer functions or data in other object files. For
example, if you compile a function which calls a non-local function
`foo`, the resulting code contains something like this:
```
26: e8 00 00 00 00 callq 2b <bar+0xb>
27: R_X86_64_PLT32 foo-0x4
```
The above `callq` is the instruction to call a function at the
machine code level. It's opcode is `0xe8` in x86-64, so the
instruction begins with `0xe8`. The following four bytes are
displacement; that is, the address of the branch target relative to
the end of this `callq` instruction. Notice that the displacement is
0. The compiler couldn't fill the displacement because it has no
idea as to where `foo` will be at runtime. So, the compiler write 0
as a placeholder and instead write a relocation `R_X86_64_PLT32`
with `foo` as its associated symbol. The linker reads this
relocation, computes the offsets between this call instruction and
function `foo` and overwrite the placeholder value 0 with an actual
displacement.
There are many different types of relocations. For example, if you
want to fix up not with a displacement but with an absolute address
of a symbol, you need to use `R_X86_64_ABS64` instead.
## Static library
A .a file. Often called as an archive file or just archive as well.
A static library is a container just like tar or zip. Actually,
there's no technical reason to not use tar or (uncompressed) zip,
but traditionally the .a file format is used by the linker.
A static library contains object files and can be passed to the
linker along with other object files and/or archives.
A linker pulls out object files from an archive only if it is needed
to resolve undefined symbols. In other words, object files in an
archive are not linked by default and used as a complement to supply
missing definitions. This is ideal for a library because you don't
want to link library functions unless you are actually using them.
Contrary to archive files, object files directly given to a linker
are always linked to the output.
To maximize the benefit of archive files, a library often used as a
static library is broken down to small files to separate each
function individually (for example, look at
https://git.musl-libc.org/cgit/musl/tree/src/stdio). By doing this,
you import only used functions.
A static file is created by `ar`, whose command line arguments are
similar to `tar`. A static library contains the symbol table which
offers a quick way to look up an object file for a defined symbol,
but mold does not use the static library's symbol table. mold
doesdn't need a symbol table to exist in an archive, and if exists,
mold just ignores it.
See also: DSO (dynamic library)
## Symbol
A symbol is a label assigned to a specific location in an input file
or an output file. For example, if you define function `foo` and
compile it, the resulting object file contains a symbol `foo`
pointing to the beginning of the machine code for `foo`.
Usually, a symbol name is a function or a variable name. If an
object is anonymous (such the one for a string literal), a compiler
generated a unique symbol, which often starts with `.` to avoid
conflict with user-defined symbols.
For C++, symbol name is a complex "mangled" name. We need to mangle
identifiers because a simple name such as `foo` cannot be uniquely
identify a function or a data in C++, because for example `foo` may
be in a namespace or defined as a static member in some class. If
`foo` is an overloaded function, we need to distinguish different
`foo`s by its type. Therefore, C++ compiler mangles an identifier by
appending nmaepsace names, type information and such so that
different things get different names.
For example, a function `int foo(int)` in a namespace `bar` is
mangled as `_ZN3bar3fooEi`.
A symbol can be either defined or undefined. A defined symbol points
to some location in a file which may contain the function's machine
code or the variable's initial value. An undefined symbol does not
point to anywhere. It needs to be merged with a defined symbol with
the same name at link-time. This merging process is called "name
resolution".
For example, if your program is using `printf`, it usually contains
`printf` as an undefined symbol. You need to link it with `libc.a`
or `libc.so`, which contain a defined symbol of `printf`, to make a
complete program.
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# Instrumenting mold with MemorySanitizer
## Introduction
Per <https://github.com/google/sanitizers/wiki/MemorySanitizerLibcxxHowTo>:
> If you want MemorySanitizer to work properly and not produce any false
> positives, you must ensure that all the code in your program and in
> libraries it uses is instrumented (i.e. built with `-fsanitize=memory`).
> In particular, you would need to link against an MSan-instrumented C++
> standard library. We recommend to use [libc++](https://libcxx.llvm.org/)
> for that purpose.
## Building instrumented libc++
Build an MSan-instrumented libc++ from source:
```sh
cd ~
git clone https://github.com/llvm/llvm-project
cd llvm-project
cmake -S ./runtimes -B build-libcxx -G Ninja \
-DCMAKE_BUILD_TYPE=Release \
-DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi" \
-DCMAKE_C_COMPILER=clang \
-DCMAKE_CXX_COMPILER=clang++ \
-DLLVM_USE_SANITIZER=MemoryWithOrigins
cmake --build build-libcxx -- cxx cxxabi
export LIBCXX="$HOME/llvm-project/build-libcxx" # for subsequent build steps
```
Upon success, `./build-libcxx/{include,lib}` will contain the resulting
headers and shared libraries.
## Linking mold against instrumented libc++
Use the `MOLD_USE_MSAN` and `MOLD_STDLIB_PREFIX` cmake variables to link
mold against the instrumented build of libc++:
```sh
cd ~
git clone https://github.com/rui314/mold.git
cd mold
cmake -B build -G Ninja \
-DCMAKE_BUILD_TYPE=Debug \
-DCMAKE_C_COMPILER=clang \
-DCMAKE_CXX_COMPILER=clang++ \
-DMOLD_USE_MSAN=ON \
-DMOLD_STDLIB_PREFIX="$LIBCXX" \
-DMOLD_USE_MIMALLOC=OFF \
-DMOLD_USE_SYSTEM_TBB=ON
cmake --build build
```
Most of mold's tests (except those for `-flto`) should work at this
point. Run them like normal:
```sh
ctest --test-dir build
```
Any resulting MemorySanitizer errors should be visible in
`./build/Temporary/Testing/LastTest.log`.
## Building instrumented LTO plugin (experimental)
Exercising `-flto` with MemorySanitizer (and without false positives)
requires instrumenting the transitive dependencies of `lto-unix.cc`:
- `libiberty.a`
- `liblto_plugin.so`
- `LLVMgold.so`
> [!NOTE]
> This is more involved and time-consuming than building only libc++ from
> source. The cost-benefit ratio of this additional instrumentation and
> test coverage may be unfavorable in many cases.
> [!IMPORTANT]
> The following steps are experimental and unlikely to work exactly as-is
> under CI runners and individual developer environments. Consider the
> following a starting point rather than a complete HOWTO.
Build an MSan-instrumented GNU libiberty:
```sh
cd ~
git clone [email protected]:gcc-mirror/gcc.git
cd gcc/libiberty
export CC=clang
export CFLAGS="-g -Og -fsanitize=memory -fsanitize-memory-track-origins"
export LDFLAGS="-fsanitize=memory"
./configure
make -j$(nproc)
unset CC CFLAGS LDFLAGS
```
Install the resulting `./libiberty.a` into the build toolchain being
tested with mold. If the system image is ephemeral or disposable (e.g. a
short-lived VM or container), a quick-and-dirty install could look like:
```sh
sudo cp /usr/lib/libiberty.a{,.bak}
sudo cp ./libiberty.a /usr/lib/
```
Build an MSan-instrumented GCC LTO plugin library:
```sh
cd ~/gcc/lto-plugin # use already-cloned repo from earlier step
export CC=clang
export CFLAGS="-g -Og -fsanitize=memory -fsanitize-memory-track-origins"
export LDFLAGS="-fsanitize=memory"
./configure --with-libiberty=/usr/lib
make -j$(nproc)
unset CC CFLAGS LDFLAGS
```
Install the resulting `liblto_plugin.so`. With the same caveats discussed
above, a simple install into an ephemeral environment could look like:
```sh
export GCC_VERSION="$(gcc -dumpversion)"
sudo cp /usr/lib/gcc/x86_64-pc-linux-gnu/$GCC_VERSION/liblto_plugin.so{,.bak}
sudo cp .libs/liblto_plugin.so /usr/lib/gcc/x86_64-pc-linux-gnu/$GCC_VERSION/
```
Build an MSan-instrumented LLVM LTO plugin library:
```sh
cd ~/llvm-project # use already-cloned repo from earlier step
CF="-nostdinc++ -isystem $LIBCXX/include/c++/v1"
INCDIR="$(find /usr -name plugin-api.h -type f | head -1 | xargs dirname)"
function configure
{
cmake -S ./llvm -B build-plugin -G Ninja \
-DLLVM_ENABLE_PROJECTS=clang \
-DLLVM_TARGETS_TO_BUILD=X86 \
-DCMAKE_BUILD_TYPE=Release \
-DCMAKE_C_COMPILER=clang \
-DCMAKE_CXX_COMPILER=clang++ \
-DCMAKE_C_FLAGS="$CF" \
-DCMAKE_CXX_FLAGS="$CF" \
-DCMAKE_EXE_LINKER_FLAGS="$1" \
-DCMAKE_POSITION_INDEPENDENT_CODE=ON \
-DLLVM_BINUTILS_INCDIR="$INCDIR" \
-DLLVM_USE_SANITIZER=MemoryWithOrigins
}
# workaround for linker issues: configure twice with different LDFLAGS
configure "-nostdlib++ -L $LIBCXX/lib -Wl,--rpath=$LIBCXX/lib"
configure "-nostdlib++ -L $LIBCXX/lib -lc++ -Wl,--rpath=$LIBCXX/lib"
cmake --build build-plugin -- LLVMgold.so
```
Install the resulting `LLVMgold.so`. With the same caveats discussed
above, a simple install into an ephemeral environment could look like:
```sh
sudo cp /usr/lib/LLVMgold.so{,.bak}
sudo cp ./build-plugin/lib/LLVMgold.so /usr/lib/
```
mold's tests for `-flto` should now (mostly) work, though there do seem
to be issues around `gcc` inferring `-flto` when not explicitly specified.
One workaround is to use `clang` as `TEST_CC`:
```sh
cd ~/mold # use already-cloned and built repo from earlier step
TEST_CC=clang TEST_CXX=clang++ ctest --test-dir build
```
## References
- <https://github.com/google/sanitizers/wiki/MemorySanitizerBootstrappingClang>
- <https://llvm.org/docs/GoldPlugin.html#lto-how-to-build>
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mold(1) -- a modern linker
==========================
## SYNOPSIS
`mold` [_option_...] _file_...
## DESCRIPTION
`mold` is a faster drop-in replacement for the default GNU ld(1).
### How to use
See <https://github.com/rui314/mold#how-to-use>.
### Compatibility
`mold` is designed to be a drop-in replacement for the GNU linkers for
linking user-land programs. If your user-land program cannot be built due to
missing command-line options, please file a bug at
<https://github.com/rui314/mold/issues>.
`mold` supports a very limited set of linker script features, which is just
sufficient to read `/usr/lib/x86_64-linux-gnu/libc.so` on Linux systems (on
Linux, that file is contrary to its name not a shared library but an ASCII
linker script that loads a real `libc.so` file.)
Beyond that, we have no plan to support any additional linker script features.
The linker script is an ad-hoc, over-designed, complex language which we
believe needs to be replaced by a simpler mechanism. We have a plan to add a
replacement for the linker script to `mold` instead.
### Archive symbol resolution
Traditionally, Unix linkers are sensitive to the order in which input files
appear on the command line. They process input files from the first (leftmost)
file to the last (rightmost) file one-by-one. While reading input files, they
maintain sets of defined and undefined symbols. When visiting an archive file
(`.a` files), they pull out object files to resolve as many undefined symbols
as possible and move on to the next input file. Object files that weren't
pulled out will never have a chance for a second look.
Due to this behavior, you usually have to add archive files at the end of a
command line, so that when a linker reaches archive files, it knows what
symbols remain as undefined.
If you put archive files at the beginning of a command line, a linker doesn't
have any undefined symbols, and thus no object files will be pulled out from
archives. You can change the processing order by using the `--start-group` and
`--end-group` options, though they make a linker slower.
`mold`, as well as the LLVM lld(1) linker, takes a different approach. They
remember which symbols can be resolved from archive files instead of
forgetting them after processing each archive. Therefore, `mold` and lld(1)
can "go back" in a command line to pull out object files from archives if they
are needed to resolve remaining undefined symbols. They are not sensitive to
the input file order.
`--start-group` and `--end-group` are still accepted by `mold` and lld(1)
for compatibility with traditional linkers, but they are silently ignored.
### Dynamic symbol resolution
Some Unix linker features are difficult to understand without comprehending
the semantics of dynamic symbol resolution. Therefore, even though it's not
specific to `mold`, we'll explain it here.
We use "ELF module" or just "module" as a collective term to refer to an
executable or a shared library file in the ELF format.
An ELF module may have lists of imported symbols and exported symbols, as well
as a list of shared library names from which imported symbols should be
imported. The point is that imported symbols are not bound to any specific
shared library until runtime.
Here is how the Unix dynamic linker resolves dynamic symbols. Upon the start
of an ELF program, the dynamic linker constructs a list of ELF modules which,
as a whole, consist of a complete program. The executable file is always at
the beginning of the list followed by its dependent shared libraries. An
imported symbol is searched from the beginning of the list to the end. If two
or more modules define the same symbol, the one that appears first in the list
takes precedence over the others.
This Unix semantics are contrary to systems such as Windows that have a
two-level namespace for dynamic symbols. On Windows, for example, dynamic
symbols are represented as a tuple of (`symbol-name`, `shared-library-name`),
so that each dynamic symbol is guaranteed to be resolved from some specific
library.
Typically, an ELF module that exports a symbol also imports the same symbol.
Such a symbol is usually resolved to itself, but that's not the case if a
module that appears before it in the symbol search list provides another
definition of the same symbol.
Let's take `malloc` as an example. Assume that you define your version of
`malloc` in your main executable file. Then, all `malloc` calls from any
module are resolved to your function instead of the one in libc, because the
executable is always at the beginning of the dynamic symbol search list. Note
that even `malloc` calls within libc are resolved to your definition since
libc exports and imports `malloc`. Therefore, by defining `malloc` yourself,
you can overwrite a library function, and the `malloc` in libc becomes dead
code.
These Unix semantics are tricky and sometimes considered harmful. For example,
assume that you accidentally define `atoi` as a global function in your
executable that behaves completely differently from the one in the C standard.
Then, all `atoi` function calls from any modules (even function calls within
libc) are redirected to your function instead of the one in libc, which will
very likely cause a problem. That is a somewhat surprising consequence for an
accidental name conflict. On the other hand, this semantic is sometimes useful
because it allows users to override library functions without rebuilding
modules containing them.
Whether good or bad, you should keep these semantics in mind to understand
Unix linkers' behaviors.
### Build reproducibility
`mold`'s output is deterministic. That is, if you pass the same object files
and the same command-line options to the same version of `mold`, it is
guaranteed that `mold` produces the bit-for-bit identical output. The linker's
internal randomness, such as the timing of thread scheduling or iteration
orders of hash tables, doesn't affect the output.
`mold` does not have any host-specific default settings. This is contrary to the
GNU linkers, for which some configurable values, such as system-dependent
library search paths, are hard-coded. `mold` depends only on its command-line
arguments.
## OPTION NOTATIONS
Multi-letter long options may precede either a single dash or double dashes,
except for those starting with the letter "o". For historical reasons, long
options beginning with "o" must precede double dashes.
For example, you can spell `--as-needed` as `-as-needed`, but `--omagic` must
not be spelled as `-omagic`. `-omagic` will be interpreted not as `--omagic`
but as `-o magic`.
## MOLD-SPECIFIC OPTIONS
* `--chroot`=_dir_:
Set _dir_ as the root directory.
* `--color-diagnostics`=[ _auto_ | _always_ | _never_ ]:
Show diagnostic messages in color using ANSI escape sequences. `auto` means
that `mold` prints out messages in color only if the standard output is
connected to a TTY. Default is `auto`.
* `--color-diagnostics`:
Synonym for `--color-diagnostics=auto`.
* `--no-color-diagnostics`:
Synonym for `--color-diagnostics=never`.
* `--detach`, `--no-detach`:
Permit or do not permit mold to create a debug info file in the background.
* `--fork`, `--no-fork`:
Spawn a child process and let it do the actual linking. When linking a large
program, the OS kernel can take a few hundred milliseconds to terminate a
`mold` process. `--fork` hides that latency. By default, it does fork.
Note that `--fork` also hides the resource usage statistics reported by
time(2), since it doesn't call waitpid(2) on the child process. If you
need those statistics, pass `--no-fork`.
* `--perf`:
Print performance statistics.
* `--print-dependencies`:
Print out dependency information for input files.
Each line of the output for this option shows which file depends on which
file to use a specific symbol. This option is useful for debugging why some
object file in a static archive got linked or why some shared library is
kept in an output file's dependency list even with `--as-needed`.
* `--relocatable-merge-sections`:
By default, `mold` doesn't merge input sections by name when merging input
object files into a single output object file for `-r`. For example,
`.text.foo` and `.text.bar` aren't merged for `-r` even though they are
merged into `.text` based on the default section merging rules.
This option changes the behavior so that `mold` merges input sections by
name by the default section merging rules.
* `--repro`:
Archive input files, as well as a text file containing command line options,
in a tar file so that you can run `mold` with the exact same inputs again.
This is useful for reporting a bug with a reproducer. The output filename is
`path/to/output.tar`, where `path/to/output` is an output filename specified
by `-o`.
* `--reverse-sections`:
Reverse the order of input sections before assigning them the offsets in the
output file.
This option is useful for finding bugs that depend on the initialization
order of global objects. In C++, constructors of global objects in a single
source file are guaranteed to be executed in the source order, but there's
no such guarantee across compilation units. Usually, constructors are
executed in the order given to the linker, but depending on it is a mistake.
By reversing the order of input sections using `--reverse-sections`, you can
easily test that your program works in the reversed initialization order.
* `--run` _command_ _arg_...:
Run _command_ with `mold` as `/usr/bin/ld`. Specifically, `mold` runs a
given command with the `LD_PRELOAD` environment set to intercept exec(3)
family functions and replaces `argv[0]` with itself if it is `ld`,
`ld.gold`, or `ld.lld`.
* `--separate-debug-file`, `--separate-debug-file`=_file_:
Bundle debug info sections into a separate file instead of embedding them in
an output executable or a shared library. mold creates a debug info file in
the background by default, so that you can start running your executable as
soon as possible.
By default, the debug info file is created in the same directory as is the
output file, with the `.dbg` file extension. That filename is embedded into
the output file so that `gdb` can automatically find the debug info file for
the output file. For more info about gdb features related to separate debug
files, see
<https://sourceware.org/gdb/current/onlinedocs/gdb.html/Separate-Debug-Files.html>.
mold holds a file lock with flock(2) while creating a debug info file in the
background.
If you don't want to create a debug info file in the background, pass the
`--no-detach` option.
* `--shuffle-sections`, `--shuffle-sections`=_number_:
Randomize the output by shuffling the order of input sections before
assigning them the offsets in the output file. If a _number_ is given, it's
used as a seed for the random number generator, so that the linker produces
the same output for the same seed. If no seed is given, a random number is
used as a seed.
This option is useful for benchmarking. Modern CPUs are sensitive to a
program's memory layout. A seemingly benign change in program layout, such
as a small size increase of a function in the middle of a program, can
affect the program's performance. Therefore, even if you write new code and
get a good benchmark result, it is hard to say whether the new code improves
the program's performance; it is possible that the new memory layout happens
to perform better.
By running a benchmark multiple times with randomized memory layouts using
`--shuffle-sections`, you can isolate your program's real performance number
from the randomness caused by memory layout changes.
* `--spare-program-headers`=_number_:
Append the given number of `PT_NULL` entries to the end of the program
header, so that post-link processing tools can easily add new segments by
overwriting the null entries.
Note that ELF requires all `PT_LOAD` segments to be sorted by `p_vaddr`.
Therefore, if you add a new LOAD segment, you may need to sort the entire
program header.
* `--stats`:
Print input statistics.
* `--thread-count`=_count_:
Use _count_ number of threads.
* `--threads`, `--no-threads`:
Use multiple threads. By default, `mold` uses as many threads as the number of
cores or 32, whichever is smaller. The reason it is capped at 32 is because
`mold` doesn't scale well beyond that point. To use only one thread, pass
`--no-threads` or `--thread-count=1`.
* `--quick-exit`, `--no-quick-exit`:
Use or do not use `quick_exit` to exit.
* `--zero-to-bss`:
Convert all-zero data sections into BSS.
When this option is enabled, `mold` scans input data sections that are not
of type `SHT_NOBITS` and checks whether their contents consist solely of
zero bytes. Such sections are then converted into BSS (`SHT_NOBITS`)
sections. This reduces the size of the output file, since BSS sections
occupy no space in the file image.
This behavior is especially useful for user-defined sections created with
`__attribute__((section(".sectname")))` that contain uninitialized global
variables. GCC and Clang do not automatically mark such sections as BSS
even if their contents are entirely zero, and instead emit them as regular
data sections.
For example, consider `__attribute__((section(".sectname"))) int vec[256];`.
By default, this results in a `.sectname` section of type `SHT_PROGBITS`
filled with zeros. With `--zero-to-bss`, the linker will recognize it as
empty data and convert it to a `SHT_NOBITS` section, reducing the output
file size without changing runtime semantics.
* `-z rewrite-endbr`, `-z norewrite-endbr`:
As a security measure, some CPU instruction sets have recently gained a
feature to protect control flow integrity by disallowing indirect branches
by default. If the feature is enabled, the instruction that is executed
immediately after an indirect branch must be an branch target marker
instruction, or a CPU-level fault will raise. The marker instruction is also
known as "landing pad" instruction, to which indirect branches can land.
This feature makes ROP attacks harder to conduct.
To use the feature, a function whose pointer is taken needs to begin with a
landing pad because a function call via a function pointer is compiled to an
indirect branch. On the other hand, if a function is called only directly
(i.e. referred to only by _direct_ branch instructions), it doesn't have to
begin with it.
By default, the compiler always emits a landing pad at the beginning of each
global function because it doesn't know whether or not the function's
pointer is taken in another translation unit. As a result, the resulting
binary has more attack surface than necessary.
If `--rewrite-endbr` is given, mold conducts a whole program analysis
to identify functions whose addresses are actually taken and rewrites
landing pads with no-ops for non-address-taken functions, reducing the
attack surface.
This feature is currently available only on x86-64.
## GNU-COMPATIBLE OPTIONS
* `--help`:
Report usage information to stdout and exit.
* `-v`, `--version`:
Report version information to stdout.
* `-V`:
Report version and target information to stdout.
* `-E`, `--export-dynamic`, `--no-export-dynamic`:
When creating an executable, using the `-E` option causes all global symbols
to be put into the dynamic symbol table, so that the symbols are visible
from other ELF modules at runtime.
By default, or if `--no-export-dynamic` is given, only symbols that are
referenced by DSOs at link-time are exported from an executable.
* `-F` _libname_, `--filter`=_libname_:
Set the `DT_FILTER` dynamic section field to _libname_.
* `-I` _file_, `--dynamic-linker`=_file_, `--no-dynamic-linker`:
Set the dynamic linker path to _file_. If no `-I` option is given, or if
`--no-dynamic-linker` is given, no dynamic linker path is set to an output
file. This is contrary to the GNU linkers which set a default dynamic linker
path in that case. This difference doesn't usually make any difference
because the compiler driver always passes `-I` to the linker.
* `-L` _dir_, `--library-path`=_dir_:
Add _dir_ to the list of library search paths from which `mold` searches
libraries for the `-l` option.
Unlike the GNU linkers, `mold` does not have default search paths. This
difference doesn't usually make any difference because the compiler driver
always passes all necessary search paths to the linker.
* `-M`, `--print-map`:
Write a map file to stdout.
* `-N`, `--omagic`, `--no-omagic`:
Force `mold` to emit an output file with an old-fashioned memory layout.
First, it makes the first data segment not aligned to a page boundary.
Second, text segments are marked as writable if the option is given.
* `-S`, `--strip-debug`:
Omit `.debug_*` sections from the output file.
* `-T` _file_, `--script`=_file_:
Read linker script from _file_.
* `-X`, `--discard-locals`:
Discard temporary local symbols to reduce the sizes of the symbol table and
the string table. Temporary local symbols are local symbols starting with
`.L`. Compilers usually generate such symbols for unnamed program elements
such as string literals or floating-point literals.
* `-e` _symbol_, `--entry`=_symbol_:
Use _symbol_ as the entry point symbol instead of the default entry
point symbol _start.
* `-f` _shlib_, `--auxiliary`=_shlib_:
Set the `DT_AUXILIARY` dynamic section field to _shlib_.
* `-h` _libname_, `--soname`=_libname_:
Set the `DT_SONAME` dynamic section field to _libname_. This option is used
when creating a shared object file. Typically, when you create `libfoo.so`,
you want to pass `--soname=foo` to a linker.
* `-l` _libname_:
Search for `lib`_libname_`.so` or `lib`_libname_`.a` from library search
paths.
* `-m` _target_:
Choose a _target_.
* `-o` _file_, `--output`=_file_:
Use _file_ as the output file name instead of the default name `a.out`.
* `-r`, `--relocatable`:
Instead of generating an executable or a shared object file, combine input
object files to generate another object file that can be used as an input to
a linker.
* `-s`, `--strip-all`:
Omit `.symtab` section from the output file.
* `-u` _symbol_, `--undefined`=_symbol_:
If _symbol_ remains as an undefined symbol after reading all object files,
and if there is a static archive that contains an object file defining
_symbol_, pull out the object file and link it so that the output file
contains a definition of _symbol_.
* `-y` _symbol_, `--trace-symbol`=_symbol_:
Trace references to _symbol_.
* `--Bdynamic`:
Link against shared libraries.
* `--Bstatic`:
Do not link against shared libraries.
* `--Bsymbolic`:
When creating a shared library, make global symbols export-only (i.e. do not
import the same symbol). As a result, references within a shared library are
always resolved locally, negating symbol override at runtime. See "Dynamic
symbol resolution" for more information about symbol imports and exports.
* `--Bsymbolic-functions`:
This option has the same effect as `--Bsymbolic` but works only for function
symbols. Data symbols remain being both imported and exported.
* `--Bsymbolic-non-weak`:
This option has the same effect as `--Bsymbolic` but works only for non-weak
symbols. Weak symbols remain being both imported and exported.
* `--Bsymbolic-non-weak-functions`:
This option has the same effect as `--Bsymbolic` but works only for non-weak
function symbols. Data symbols and weak function symbols remain being both
imported and exported.
* `--Bno-symbolic`:
Cancel `--Bsymbolic`, `--Bsymbolic-functions`, `--Bsymbolic-non-weak` and
`--Bsymbolic-non-weak-functions`.
* `--Map`=_file_:
Write map file to _file_.
* `--Tbss`=_address_:
Alias for `--section-start=.bss=`_address_.
* `--Tdata`=_address_:
Alias for `--section-start=.data=`_address_.
* `--Ttext`=_address_:
Alias for `--section-start=.text=`_address_.
* `--allow-multiple-definition`:
Normally, the linker reports an error if there are more than one definition
of a symbol. This option changes the default behavior so that it doesn't
report an error for duplicate definitions and instead use the first
definition.
* `--allow-shlib-undefined`, `--no-allow-shlib-undefined`:
Even if mold succeeds in linking a main executable without undefined symbol
errors, you may still encounter symbol lookup errors at runtime because the
dynamic linker cannot find some symbols in shared libraries in any ELF
module. This occurs because mold ignores undefined symbols in shared
libraries by default.
If you pass `--no-allow-shlib-undefined`, mold verifies that undefined
symbols in shared libraries given to the linker can be resolved at
link-time. In other words, this converts the runtime error to a link-time
error.
Note that you need to pass all shared libraries, including indirectly
dependent ones, to the linker as arguments for `-l`. If a shared library
depends on a library that's not passed to the linker, the verification will
be skipped for that file.
* `--as-needed`, `--no-as-needed`:
By default, shared libraries given to the linker are unconditionally added
to the list of required libraries in an output file. However, shared
libraries after `--as-needed` are added to the list only when at least one
symbol is actually used by the output file. In other words, shared libraries
after `--as-needed` are not added to the list of needed libraries if they
are not needed by a program.
The `--no-as-needed` option restores the default behavior for subsequent
files.
* `--build-id`=[ `md5` | `sha1` | `sha256` | `fast` | `uuid` | `0x`_hexstring_ | `none` ]:
Create a `.note.gnu.build-id` section containing a byte string to uniquely
identify an output file. `sha256` compute a 256-bit cryptographic hash of an
output file and set it to build-id. `md5` and `sha1` compute the same hash
but truncate it to 128 and 160 bits, respectively, before setting it to
build-id. `uuid` sets a random 128-bit UUID. `0x`_hexstring_ sets
_hexstring_. `fast` is a synonym for `sha256`.
* `--build-id`:
Synonym for `--build-id=sha256`.
* `--no-build-id`:
Synonym for `--build-id=none`.
* `--compress-debug-sections`=[ `zlib` | `zlib-gabi` | `zlib:`_N_ | `zstd` | `zstd:`_N_ | `none` ]:
Compress DWARF debug info (`.debug_*` sections) using the zlib or zstd
compression algorithm. `zlib-gabi` is an alias for `zlib`. `zlib:`_N_
selects the zlib compression level, where _N_ is between 0 and 9 (0
means no compression), and `zstd:`_N_ selects the zstd compression
level, where _N_ is between 1 and 22. Higher levels achieve better
compression ratios but are slower. `zlib` is equivalent to `zlib:1`
and `zstd` is equivalent to `zstd:3`.
* `--defsym`=_symbol_=_value_:
Define _symbol_ as an alias for _value_.
_value_ is either an integer (in decimal or hexadecimal with `0x` prefix) or
a symbol name. If an integer is given as a value, _symbol_ is defined as an
absolute symbol with the given value.
* `--default-symver`:
Use soname as a symbol version and append that version to all symbols.
* `--demangle`, `--no-demangle`:
Demangle C++ and Rust symbols in log messages.
* `--dependency-file`=_file_:
Write a dependency file to _file_. The contents of the written file is
readable by make(1), which defines only one rule with the linker's output
file as a target and all input files as its prerequisites. Users are
expected to include the generated dependency file into a Makefile to
automate the dependency management. This option is analogous to the
compiler's `-MM -MF` options.
* `--dynamic-list`=_file_:
Read a list of dynamic symbols from _file_. Same as
`--export-dynamic-symbol-list`, except that it implies `--Bsymbolic`. If
_file_ does not exist in the current directory, it is searched from library
search paths for the sake of compatibility with GNU ld.
* `--eh-frame-hdr`, `--no-eh-frame-hdr`:
Create `.eh_frame_hdr` section.
* `--emit-relocs`:
The linker usually "consumes" relocation sections. That is, the linker
applies relocations to other sections, and relocation sections themselves
are discarded.
The `--emit-relocs` instructs the linker to leave relocation sections in the
output file. Some post-link binary analysis or optimization tools such as
LLVM Bolt need them.
* `--enable-new-dtags`, `--disable-new-dtags`:
By default, `mold` emits `DT_RUNPATH` for `--rpath`. If you pass
`--disable-new-dtags`, `mold` emits `DT_RPATH` for `--rpath` instead.
* `--execute-only`:
Traditionally, setting the executable bit to 1 for a memory page implies
that the page also become readable, which allows machine code to be read
as data at runtime. That is actually what an attacker often does after
gaining a limited control of a process to find pieces of machine code
they can use to gain the full control of the process. As a mitigation,
recent processors including some ARM64 ones allows "execute-only" pages.
If a page is execute-only, you can call a function there as long as you
know its address but can't read it as data.
This option marks text segments as execute-only by setting just the "X"
bit instead of "RX". Note that on most systems, the absence of the "R"
bit in the text segment serves just as a hint. If you run a program
linked with `--execute-only` on a processor that doesn't support
execute-only pages, your executable will likely still function normally,
but the text segment will remain readable.
* `--exclude-libs`=_libraries_ ...:
Mark all symbols in the given _libraries_ hidden.
* `--export-dynamic-symbol`=_symbol_:
Put symbols matching _symbol_ in the dynamic symbol table. _symbol_ may be a
glob pattern in the same syntax as for the `--export-dynamic-symbol-list` or
`--version-script` options.
* `--export-dynamic-symbol-list`=_file_:
Read a list of dynamic symbols from _file_.
* `--fatal-warnings`, `--no-fatal-warnings`:
Treat warnings as errors.
* `--fini`=_symbol_:
Call _symbol_ at unload-time.
* `--gc-sections`, `--no-gc-sections`:
Remove unreferenced sections.
* `--gdb-index`:
Create a `.gdb_index` section to speed up GNU debugger. To use this, you
need to compile source files with the `-ggnu-pubnames` compiler flag.
* `--hash-style`=[ `sysv` | `gnu` | `both` | `none` ]:
Set hash style.
* `--icf`=[ `safe` | `all` | `none` ], `--no-icf`:
It is not uncommon for a program to contain many identical functions that
differ only in name. For example, a C++ template `std::vector` is very
likely to be instantiated to the identical code for `std::vector<int>` and
`std::vector<unsigned>` because the container cares only about the size of
the parameter type. Identical Code Folding (ICF) is a size optimization to
identify and merge such identical functions.
If `--icf=all` is given, `mold` tries to merge all identical functions. This
reduces the size of the output most, but it is not a "safe" optimization. It
is guaranteed in C and C++ that two pointers pointing two different
functions will never be equal, but `--icf=all` breaks that assumption as two
identical functions have the same address after merging. So a care must be
taken when you use this flag that your program does not depend on the
function pointer uniqueness.
`--icf=safe` is a flag to merge functions only when it is safe to do so.
That is, if a program does not take an address of a function, it is safe to
merge that function with other function, as you cannot compare a function
pointer with something else without taking an address of a function.
`--icf=safe` needs to be used with a compiler that supports `.llvm_addrsig`
section which contains the information as to what symbols are address-taken.
LLVM/Clang supports that section by default. Since GCC does not support it
yet, you cannot use `--icf=safe` with GCC (it doesn't do any harm but can't
optimize at all.)
`--icf=none` and `--no-icf` disables ICF.
* `--ignore-data-address-equality`:
Make ICF to merge not only functions but also data. This option should be
used in combination with `--icf=all`.
* `--image-base`=_addr_:
Set the base address to _addr_.
* `--init`=_symbol_:
Call _symbol_ at load-time.
* `--no-undefined`:
Report undefined symbols (even with `--shared`).
* `--noinhibit-exec`:
Create an output file even if errors occur.
* `--package-metadata`=_percent-encoded-string_:
Embed a specified string into the `.note.package` section. This option
is designed for build scripts that generate binary packages, such as
`.rpm` or `.deb`, to include package metadata in each executable. It
simplifies the process of identifying the corresponding package for a
given executable or core file.
An argument to this option is treated as percent-encoded and decoded
before being inserted into the section, allowing you to avoid the use of
the comma (`,`) character in the argument. This is useful because the
compiler replaces all occurrences of commas in `-Wl,` with spaces before
forwarding them to the linker. Note that `mold` always interprets the
argument as percent-encoded, so you also need to escape all occurrences
of `%` as `%25`.
* `--pack-dyn-relocs`=[ `relr` | `android` | `android+relr` | `none` ]:
Compress dynamic relocations in the output file.
If `relr` is specified, all `R_*_RELATIVE` relocations are put into
`.relr.dyn` section instead of `.rel.dyn` or `.rela.dyn` section. Since
`.relr.dyn` section uses a space-efficient encoding scheme, specifying this
flag can reduce the size of the output. This is typically most effective for
position-independent executable.
If `android` is specified, all dynamic relocations are encoded in Android's
packed relocation format (APS2) and stored in the `.rel.dyn` or `.rela.dyn`
section, whose section type is changed to `SHT_ANDROID_REL` or
`SHT_ANDROID_RELA`. The dynamic table is updated to use `DT_ANDROID_REL`
/ `DT_ANDROID_RELA` and their `SZ` variants in place of the standard tags.
`android+relr` combines both: `R_*_RELATIVE` relocations go to `.relr.dyn`
and the rest are APS2-encoded. This is the configuration used by most
Android system binaries.
Note that a runtime loader has to support `.relr.dyn` to run executables or
shared libraries linked with `--pack-dyn-relocs=relr`. As of 2026, glibc
(since 2.36), musl (since 1.2.4), Android, ChromeOS, and Fuchsia all
support it. The APS2 format, on the other hand, is only handled by
Android's bionic loader; the encoder itself is target-agnostic, but the
produced binary can only be loaded on platforms where bionic (or a
compatible loader) handles `DT_ANDROID_REL(A)`.
* `--pie`, `--pic-executable`, `--no-pie`, `--no-pic-executable`:
Create a position-independent executable.
* `--print-gc-sections`, `--no-print-gc-sections`:
Print removed unreferenced sections.
* `--print-icf-sections`, `--no-print-icf-sections`:
Print folded identical sections.
* `--push-state`, `--pop-state`:
`--push-state` saves the current values of `--as-needed`, `--whole-archive`,
`--static`, and `--start-lib`. The saved values can be restored by
pop-state.
`--push-state` and `--pop-state` pairs can nest.
These options are useful when you want to construct linker command line
options programmatically. For example, if you want to link `libfoo.so` by
as-needed basis but don't want to change the global state of `--as-needed`,
you can append `--push-state --as-needed -lfoo --pop-state` to the linker
command line options.
* `--relax, --no-relax`:
Rewrite machine instructions with more efficient ones for some relocations.
The feature is enabled by default.
* `--require-defined`=_symbol_:
Like `--undefined`, except the new symbol must be defined by the end of the
link.
* `--retain-symbols-file`=_file_:
Keep only symbols listed in _file_. _file_ is a text file containing a
symbol name on each line. `mold` discards all local symbols as well as
global symbol that are not in _file_. Note that this option removes symbols
only from `.symtab` section and does not affect `.dynsym` section, which is
used for dynamic linking.
* `--rpath`=_dir_:
Add _dir_ to runtime search paths.
* `--section-start`=_section_=_address_:
Set _address_ to section. _address_ is a hexadecimal number that may start
with an optional `0x`.
* `--shared`, `--Bshareable`:
Create a share library.
* `--spare-dynamic-tags`=_number_:
Append the given number of `DT_NULL` entries to the end of the `.dynamic`
section, so that post-link processing tools can easily add new dynamic tags
by overwriting the null entries.
* `--start-lib`, `--end-lib`:
Handle object files between `--start-lib` and `--end-lib` as if they were in
an archive file. That means object files between them are linked only when
they are needed to resolve undefined symbols. The options are useful if you
want to link object files only when they are needed but want to avoid the
overhead of running ar(3).
* `--static`:
Do not link against shared libraries.
* `--sysroot`=_dir_:
Set target system root directory to _dir_.
* `--trace`:
Print name of each input file.
* `--undefined-glob`=_pattern_:
Synonym for `--undefined`, except that `--undefined-glob` takes a glob
pattern instead of just a single symbol name.
* `--undefined-version`, `--no-undefined-version`:
By default, `mold` warns on a symbol specified by a version script or by
`--export-dynamic-symbol` if it is not defined. You can silence the warning
by `--undefined-version`.
* `--unique`=_pattern_:
Don't merge input sections that match the given glob pattern _pattern_.
* `--unresolved-symbols`=[ `report-all` | `ignore-all` | `ignore-in-object-files` | `ignore-in-shared-libs` ]:
How to handle undefined symbols.
* `--version-script`=_file_:
Read version script from _file_. If _file_ does not exist in the current
directory, it is searched from library search paths for the sake of
compatibility with GNU ld.
* `-w`, `--no-warnings`:
Suppress warnings and cancel `--fatal-warnings`.
* `--warn-common`, `--no-warn-common`:
Warn about common symbols.
* `--warn-once`:
Only warn once for each undefined symbol instead of warn for each relocation
referring an undefined symbol.
* `--warn-unresolved-symbols`, `--error-unresolved-symbols`:
Normally, the linker reports an error for unresolved symbols.
`--warn-unresolved-symbols` option turns it into a warning.
`--error-unresolved-symbols` option restores the default behavior.
* `--whole-archive`, `--no-whole-archive`:
When archive files (`.a` files) are given to the linker, only object files
that are needed to resolve undefined symbols are extracted from them and
linked to an output file. `--whole-archive` changes that behavior for
subsequent archives so that the linker extracts all object files and links
them to an output. For example, if you are creating a shared object file and
you want to include all archive members to the output, you should pass
`--whole-archive`. `--no-whole-archive` restores the default behavior for
subsequent archives.
* `--wrap`=_symbol_:
Make _symbol_ be resolved to `__wrap_`_symbol_. The original symbol can be
resolved as `__real_`_symbol_. This option is typically used for wrapping an
existing function.
* `-z cet-report`=[ `warning` | `error` | `none` ]:
Intel Control-flow Enforcement Technology (CET) is a new x86 feature
available since Tiger Lake which is released in 2020. It defines new
instructions to harden security to protect programs from control hijacking
attacks. You can tell the compiler to use the feature by specifying the
`-fcf-protection` flag.
`-z cet-report` flag is used to make sure that all object files were
compiled with a correct `-fcf-protection` flag. If `warning` or `error` are
given, `mold` prints out a warning or an error message if an object file was
not compiled with the compiler flag.
`mold` looks for `GNU_PROPERTY_X86_FEATURE_1_IBT` bit and
`GNU_PROPERTY_X86_FEATURE_1_SHSTK` bit in `.note.gnu.property` section to
determine whether or not an object file was compiled with `-fcf-protection`.
* `-z now`, `-z lazy`:
By default, functions referring to other ELF modules are resolved by the
dynamic linker when they are called for the first time. `-z now` marks an
executable or a shared library file so that all dynamic symbols are resolved
when a file is loaded to memory. `-z lazy` restores the default behavior.
* `-z origin`:
Mark object requiring immediate `$ORIGIN` processing at runtime.
* `-z ibt`:
Turn on `GNU_PROPERTY_X86_FEATURE_1_IBT` bit in `.note.gnu.property` section
to indicate that the output uses IBT-enabled PLT. This option implies `-z
ibtplt`.
* `-z ibtplt`:
Generate Intel Branch Tracking (IBT)-enabled PLT which is the default on
x86-64. This is the default.
* `-z execstack`, `-z noexecstack`:
By default, the pages for the stack area (i.e. the pages where local
variables reside) are not executable for security reasons. `-z execstack`
makes it executable. `-z noexecstack` restores the default behavior.
* `-z keep-text-section-prefix`, `-z nokeep-text-section-prefix`:
Keep `.text.hot`, `.text.unknown`, `.text.unlikely`, `.text.startup`, and
`.text.exit` as separate sections in the final binary instead of merging
them as `.text`.
* `-z rodynamic`:
Make the `.dynamic` section read-only.
* `-z relro`, `-z norelro`:
Some sections such as `.dynamic` have to be writable only during a module is
being loaded to memory. Once the dynamic linker finishes its job, such
sections won't be mutated by anyone. As a security mitigation, it is
preferred to make such segments read-only during program execution.
`-z relro` puts such sections into a special segment called `relro`. The
dynamic linker makes a relro segment read-only after it finishes its job.
By default, `mold` generates a relro segment. `-z norelro` disables the
feature.
* `-z sectionheader`, `-z nosectionheader`:
`-z nosectionheader` tell the linker to omit the section header.
By default, the linker does not omit the section header.
* `-z separate-loadable-segments`, `-z separate-code`, `-z noseparate-code`:
If one memory page contains multiple segments, the page protection bits are
set in such a way that the needed attributes (writable or executable) are
satisfied for all segments. This usually happens at a boundary of two
segments with two different attributes.
`separate-loadable-segments` adds paddings between segments with different
attributes so that they do not share the same page.
`separate-code` adds paddings only between executable and non-executable
segments. This is the default.
`noseparate-code` does not add any paddings between segments.
* `-z defs`, `-z nodefs`:
Report undefined symbols (even with `--shared`).
* `-z shstk`:
Enforce shadow stack by turning `GNU_PROPERTY_X86_FEATURE_1_SHSTK` bit in
`.note.gnu.property` output section. Shadow stack is part of Intel
Control-flow Enforcement Technology (CET), which is available since Tiger
Lake (2020).
* `-z start_stop_visibility`=[ `hidden` | `protected` ]:
If a section name is valid as a C identifier (i.e., it matches
`/^[_a-zA-Z][_a-zA-Z0-9]*$/`), mold creates `__start_SECNAME` and
`__stop_SECNAME` symbols to mark the beginning and end of the section,
where `SECNAME` is the section name.
You can make these marker symbols visible from other ELF modules by passing
`-z start_stop_visibility=protected`. Default is `hidden`.
* `-z text`, `-z notext`, `-z textoff`:
`mold` by default reports an error if dynamic relocations are created in
read-only sections. If `-z notext` or `-z textoff` are given, `mold` creates
such dynamic relocations without reporting an error. `-z text` restores the
default behavior.
* `-z max-page-size`=_number_:
Some CPU ISAs support multiple memory page sizes. This option specifies the
maximum page size that an output binary can run on. In general, binaries
built for a larger page size can run on a system with a smaller page size,
but not vice versa. The default value is 4 KiB for i386, x86-64, and RISC-V,
and 64 KiB for ARM64.
* `-z nodefaultlib`:
Make the dynamic loader ignore default search paths.
* `-z nodelete`:
Mark DSO non-deletable at runtime.
* `-z nodlopen`:
Mark DSO not available to dlopen(3). This option makes it possible for the
linker to optimize thread-local variable accesses by rewriting instructions
for some targets.
* `-z nodump`:
Mark DSO not available to dldump(3).
* `-z nocopyreloc`:
Do not create copy relocations.
* `-z initfirst`:
Mark DSO to be initialized first at runtime.
* `-z interpose`:
Mark object to interpose all DSOs but executable.
* `-(`, `-)`, `-EL`, `-O`_number_, `--dc`, `--dp`, `--end-group`, `--no-add-needed`, `--no-copy-dt-needed-entries`, `--nostdlib`, `--rpath-link=Ar dir`, `--sort-common`, `--sort-section`, `--start-group`, `--warn-constructors`, `--warn-once`, `--fix-cortex-a53-835769`, `--fix-cortex-a53-843419`, `-z combreloc`, `-z common-page-size`, `-z nocombreloc`:
Ignored
## ENVIRONMENT VARIABLES
* `MOLD_JOBS`:
If this variable is set to `1`, only one `mold` process will run at a time.
If a new mold process is initiated while another is already active, the new
process will wait until the active one completes before starting.
The primary reason for this environment variable is to minimize peak memory
usage. Since mold is designed to operate with high parallelism, running
multiple mold instances simultaneously may not be beneficial. If you execute
N instances of mold concurrently, it could require N times the time and N
times the memory. On the other hand, running them one after the other might
still take N times longer, but the peak memory usage would be the same as
running just a single instance.
If your build system invokes multiple linker processes simultaneously and
some of them often get killed due to out-of-memory errors, you might
consider setting this environment variable to `1` to see if it addresses the
OOM issue.
Currently, any value other than `1` is silently ignored.
* `MOLD_DEBUG`:
If this variable is set to a non-empty string, `mold` embeds its
command-line options in the output file's `.comment` section.
* `MOLD_REPRO`:
Setting this variable to a non-empty string has the same effect as passing
the `--repro` option.
## SEE ALSO
gold(1), ld(1), elf(5), ld.so(8)
## AUTHOR
Rui Ueyama <ruiu@cs.stanford.edu>
## BUGS
Report bugs to <https://github.com/rui314/mold/issues>.
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@@ -0,0 +1,702 @@
#pragma once
#include <cstdint>
#include <endian.h>
#include <string>
#if __BYTE_ORDER == __BIG_ENDIAN
#error "mold does not support big-endian hosts"
#endif
typedef uint8_t u8;
typedef uint16_t u16;
typedef uint32_t u32;
typedef uint64_t u64;
typedef int8_t i8;
typedef int16_t i16;
typedef int32_t i32;
typedef int64_t i64;
template <typename E>
static std::string rel_to_string(u32 r_type);
struct X86_64;
struct I386;
static constexpr u32 SHN_UNDEF = 0;
static constexpr u32 SHN_ABS = 0xfff1;
static constexpr u32 SHN_COMMON = 0xfff2;
static constexpr u32 SHN_XINDEX = 0xffff;
static constexpr u32 SHT_NULL = 0;
static constexpr u32 SHT_PROGBITS = 1;
static constexpr u32 SHT_SYMTAB = 2;
static constexpr u32 SHT_STRTAB = 3;
static constexpr u32 SHT_RELA = 4;
static constexpr u32 SHT_HASH = 5;
static constexpr u32 SHT_DYNAMIC = 6;
static constexpr u32 SHT_NOTE = 7;
static constexpr u32 SHT_NOBITS = 8;
static constexpr u32 SHT_REL = 9;
static constexpr u32 SHT_SHLIB = 10;
static constexpr u32 SHT_DYNSYM = 11;
static constexpr u32 SHT_INIT_ARRAY = 14;
static constexpr u32 SHT_FINI_ARRAY = 15;
static constexpr u32 SHT_PREINIT_ARRAY = 16;
static constexpr u32 SHT_GROUP = 17;
static constexpr u32 SHT_SYMTAB_SHNDX = 18;
static constexpr u32 SHT_GNU_HASH = 0x6ffffff6;
static constexpr u32 SHT_GNU_VERDEF = 0x6ffffffd;
static constexpr u32 SHT_GNU_VERNEED = 0x6ffffffe;
static constexpr u32 SHT_GNU_VERSYM = 0x6fffffff;
static constexpr u32 SHT_X86_64_UNWIND = 0x70000001;
static constexpr u32 SHF_WRITE = 0x1;
static constexpr u32 SHF_ALLOC = 0x2;
static constexpr u32 SHF_EXECINSTR = 0x4;
static constexpr u32 SHF_MERGE = 0x10;
static constexpr u32 SHF_STRINGS = 0x20;
static constexpr u32 SHF_INFO_LINK = 0x40;
static constexpr u32 SHF_LINK_ORDER = 0x80;
static constexpr u32 SHF_GROUP = 0x200;
static constexpr u32 SHF_TLS = 0x400;
static constexpr u32 SHF_COMPRESSED = 0x800;
static constexpr u32 SHF_EXCLUDE = 0x80000000;
static constexpr u32 GRP_COMDAT = 1;
static constexpr u32 STT_NOTYPE = 0;
static constexpr u32 STT_OBJECT = 1;
static constexpr u32 STT_FUNC = 2;
static constexpr u32 STT_SECTION = 3;
static constexpr u32 STT_FILE = 4;
static constexpr u32 STT_COMMON = 5;
static constexpr u32 STT_TLS = 6;
static constexpr u32 STT_GNU_IFUNC = 10;
static constexpr u32 STB_LOCAL = 0;
static constexpr u32 STB_GLOBAL = 1;
static constexpr u32 STB_WEAK = 2;
static constexpr u32 STB_GNU_UNIQUE = 10;
static constexpr u32 STV_DEFAULT = 0;
static constexpr u32 STV_INTERNAL = 1;
static constexpr u32 STV_HIDDEN = 2;
static constexpr u32 STV_PROTECTED = 3;
static constexpr u32 VER_NDX_LOCAL = 0;
static constexpr u32 VER_NDX_GLOBAL = 1;
static constexpr u32 VER_NDX_LAST_RESERVED = 1;
static constexpr u32 VER_FLG_BASE = 1;
static constexpr u32 VER_FLG_WEAK = 2;
static constexpr u32 VER_FLG_INFO = 4;
static constexpr u32 VERSYM_HIDDEN = 0x8000;
static constexpr u32 PT_NULL = 0;
static constexpr u32 PT_LOAD = 1;
static constexpr u32 PT_DYNAMIC = 2;
static constexpr u32 PT_INTERP = 3;
static constexpr u32 PT_NOTE = 4;
static constexpr u32 PT_SHLIB = 5;
static constexpr u32 PT_PHDR = 6;
static constexpr u32 PT_TLS = 7;
static constexpr u32 PT_GNU_EH_FRAME = 0x6474e550;
static constexpr u32 PT_GNU_STACK = 0x6474e551;
static constexpr u32 PT_GNU_RELRO = 0x6474e552;
static constexpr u32 PF_X = 1;
static constexpr u32 PF_W = 2;
static constexpr u32 PF_R = 4;
static constexpr u32 ET_NONE = 0;
static constexpr u32 ET_REL = 1;
static constexpr u32 ET_EXEC = 2;
static constexpr u32 ET_DYN = 3;
static constexpr u32 ELFDATA2LSB = 1;
static constexpr u32 ELFDATA2MSB = 2;
static constexpr u32 ELFCLASS32 = 1;
static constexpr u32 ELFCLASS64 = 2;
static constexpr u32 EV_CURRENT = 1;
static constexpr u32 EM_386 = 3;
static constexpr u32 EM_X86_64 = 62;
static constexpr u32 EI_CLASS = 4;
static constexpr u32 EI_DATA = 5;
static constexpr u32 EI_VERSION = 6;
static constexpr u32 EI_OSABI = 7;
static constexpr u32 EI_ABIVERSION = 8;
static constexpr u32 ELFOSABI_NONE = 0;
static constexpr u32 ELFOSABI_GNU = 3;
static constexpr u32 DT_NULL = 0;
static constexpr u32 DT_NEEDED = 1;
static constexpr u32 DT_PLTRELSZ = 2;
static constexpr u32 DT_PLTGOT = 3;
static constexpr u32 DT_HASH = 4;
static constexpr u32 DT_STRTAB = 5;
static constexpr u32 DT_SYMTAB = 6;
static constexpr u32 DT_RELA = 7;
static constexpr u32 DT_RELASZ = 8;
static constexpr u32 DT_RELAENT = 9;
static constexpr u32 DT_STRSZ = 10;
static constexpr u32 DT_SYMENT = 11;
static constexpr u32 DT_INIT = 12;
static constexpr u32 DT_FINI = 13;
static constexpr u32 DT_SONAME = 14;
static constexpr u32 DT_RPATH = 15;
static constexpr u32 DT_SYMBOLIC = 16;
static constexpr u32 DT_REL = 17;
static constexpr u32 DT_RELSZ = 18;
static constexpr u32 DT_RELENT = 19;
static constexpr u32 DT_PLTREL = 20;
static constexpr u32 DT_DEBUG = 21;
static constexpr u32 DT_TEXTREL = 22;
static constexpr u32 DT_JMPREL = 23;
static constexpr u32 DT_BIND_NOW = 24;
static constexpr u32 DT_INIT_ARRAY = 25;
static constexpr u32 DT_FINI_ARRAY = 26;
static constexpr u32 DT_INIT_ARRAYSZ = 27;
static constexpr u32 DT_FINI_ARRAYSZ = 28;
static constexpr u32 DT_RUNPATH = 29;
static constexpr u32 DT_FLAGS = 30;
static constexpr u32 DT_GNU_HASH = 0x6ffffef5;
static constexpr u32 DT_VERSYM = 0x6ffffff0;
static constexpr u32 DT_RELACOUNT = 0x6ffffff9;
static constexpr u32 DT_RELCOUNT = 0x6ffffffa;
static constexpr u32 DT_FLAGS_1 = 0x6ffffffb;
static constexpr u32 DT_VERDEF = 0x6ffffffc;
static constexpr u32 DT_VERDEFNUM = 0x6ffffffd;
static constexpr u32 DT_VERNEED = 0x6ffffffe;
static constexpr u32 DT_VERNEEDNUM = 0x6fffffff;
static constexpr u32 DT_AUXILIARY = 0x7ffffffd;
static constexpr u32 DT_FILTER = 0x7fffffff;
static constexpr u32 DF_ORIGIN = 0x01;
static constexpr u32 DF_SYMBOLIC = 0x02;
static constexpr u32 DF_TEXTREL = 0x04;
static constexpr u32 DF_BIND_NOW = 0x08;
static constexpr u32 DF_STATIC_TLS = 0x10;
static constexpr u32 DF_1_NOW = 0x00000001;
static constexpr u32 DF_1_NODELETE = 0x00000008;
static constexpr u32 DF_1_INITFIRST = 0x00000020;
static constexpr u32 DF_1_NOOPEN = 0x00000040;
static constexpr u32 DF_1_ORIGIN = 0x00000080;
static constexpr u32 DF_1_INTERPOSE = 0x00000400;
static constexpr u32 DF_1_NODUMP = 0x00001000;
static constexpr u32 DF_1_PIE = 0x08000000;
static constexpr u32 NT_GNU_ABI_TAG = 1;
static constexpr u32 NT_GNU_HWCAP = 2;
static constexpr u32 NT_GNU_BUILD_ID = 3;
static constexpr u32 NT_GNU_GOLD_VERSION = 4;
static constexpr u32 NT_GNU_PROPERTY_TYPE_0 = 5;
static constexpr u32 GNU_PROPERTY_AARCH64_FEATURE_1_AND = 0xc0000000;
static constexpr u32 GNU_PROPERTY_X86_FEATURE_1_AND = 0xc0000002;
static constexpr u32 ELFCOMPRESS_ZLIB = 1;
static constexpr u32 R_X86_64_NONE = 0;
static constexpr u32 R_X86_64_64 = 1;
static constexpr u32 R_X86_64_PC32 = 2;
static constexpr u32 R_X86_64_GOT32 = 3;
static constexpr u32 R_X86_64_PLT32 = 4;
static constexpr u32 R_X86_64_COPY = 5;
static constexpr u32 R_X86_64_GLOB_DAT = 6;
static constexpr u32 R_X86_64_JUMP_SLOT = 7;
static constexpr u32 R_X86_64_RELATIVE = 8;
static constexpr u32 R_X86_64_GOTPCREL = 9;
static constexpr u32 R_X86_64_32 = 10;
static constexpr u32 R_X86_64_32S = 11;
static constexpr u32 R_X86_64_16 = 12;
static constexpr u32 R_X86_64_PC16 = 13;
static constexpr u32 R_X86_64_8 = 14;
static constexpr u32 R_X86_64_PC8 = 15;
static constexpr u32 R_X86_64_DTPMOD64 = 16;
static constexpr u32 R_X86_64_DTPOFF64 = 17;
static constexpr u32 R_X86_64_TPOFF64 = 18;
static constexpr u32 R_X86_64_TLSGD = 19;
static constexpr u32 R_X86_64_TLSLD = 20;
static constexpr u32 R_X86_64_DTPOFF32 = 21;
static constexpr u32 R_X86_64_GOTTPOFF = 22;
static constexpr u32 R_X86_64_TPOFF32 = 23;
static constexpr u32 R_X86_64_PC64 = 24;
static constexpr u32 R_X86_64_GOTOFF64 = 25;
static constexpr u32 R_X86_64_GOTPC32 = 26;
static constexpr u32 R_X86_64_GOT64 = 27;
static constexpr u32 R_X86_64_GOTPCREL64 = 28;
static constexpr u32 R_X86_64_GOTPC64 = 29;
static constexpr u32 R_X86_64_GOTPLT64 = 30;
static constexpr u32 R_X86_64_PLTOFF64 = 31;
static constexpr u32 R_X86_64_SIZE32 = 32;
static constexpr u32 R_X86_64_SIZE64 = 33;
static constexpr u32 R_X86_64_GOTPC32_TLSDESC = 34;
static constexpr u32 R_X86_64_TLSDESC_CALL = 35;
static constexpr u32 R_X86_64_TLSDESC = 36;
static constexpr u32 R_X86_64_IRELATIVE = 37;
static constexpr u32 R_X86_64_GOTPCRELX = 41;
static constexpr u32 R_X86_64_REX_GOTPCRELX = 42;
template <>
inline std::string rel_to_string<X86_64>(u32 r_type) {
switch (r_type) {
case R_X86_64_NONE: return "R_X86_64_NONE";
case R_X86_64_64: return "R_X86_64_64";
case R_X86_64_PC32: return "R_X86_64_PC32";
case R_X86_64_GOT32: return "R_X86_64_GOT32";
case R_X86_64_PLT32: return "R_X86_64_PLT32";
case R_X86_64_COPY: return "R_X86_64_COPY";
case R_X86_64_GLOB_DAT: return "R_X86_64_GLOB_DAT";
case R_X86_64_JUMP_SLOT: return "R_X86_64_JUMP_SLOT";
case R_X86_64_RELATIVE: return "R_X86_64_RELATIVE";
case R_X86_64_GOTPCREL: return "R_X86_64_GOTPCREL";
case R_X86_64_32: return "R_X86_64_32";
case R_X86_64_32S: return "R_X86_64_32S";
case R_X86_64_16: return "R_X86_64_16";
case R_X86_64_PC16: return "R_X86_64_PC16";
case R_X86_64_8: return "R_X86_64_8";
case R_X86_64_PC8: return "R_X86_64_PC8";
case R_X86_64_DTPMOD64: return "R_X86_64_DTPMOD64";
case R_X86_64_DTPOFF64: return "R_X86_64_DTPOFF64";
case R_X86_64_TPOFF64: return "R_X86_64_TPOFF64";
case R_X86_64_TLSGD: return "R_X86_64_TLSGD";
case R_X86_64_TLSLD: return "R_X86_64_TLSLD";
case R_X86_64_DTPOFF32: return "R_X86_64_DTPOFF32";
case R_X86_64_GOTTPOFF: return "R_X86_64_GOTTPOFF";
case R_X86_64_TPOFF32: return "R_X86_64_TPOFF32";
case R_X86_64_PC64: return "R_X86_64_PC64";
case R_X86_64_GOTOFF64: return "R_X86_64_GOTOFF64";
case R_X86_64_GOTPC32: return "R_X86_64_GOTPC32";
case R_X86_64_GOT64: return "R_X86_64_GOT64";
case R_X86_64_GOTPCREL64: return "R_X86_64_GOTPCREL64";
case R_X86_64_GOTPC64: return "R_X86_64_GOTPC64";
case R_X86_64_GOTPLT64: return "R_X86_64_GOTPLT64";
case R_X86_64_PLTOFF64: return "R_X86_64_PLTOFF64";
case R_X86_64_SIZE32: return "R_X86_64_SIZE32";
case R_X86_64_SIZE64: return "R_X86_64_SIZE64";
case R_X86_64_GOTPC32_TLSDESC: return "R_X86_64_GOTPC32_TLSDESC";
case R_X86_64_TLSDESC_CALL: return "R_X86_64_TLSDESC_CALL";
case R_X86_64_TLSDESC: return "R_X86_64_TLSDESC";
case R_X86_64_IRELATIVE: return "R_X86_64_IRELATIVE";
case R_X86_64_GOTPCRELX: return "R_X86_64_GOTPCRELX";
case R_X86_64_REX_GOTPCRELX: return "R_X86_64_REX_GOTPCRELX";
}
return "unknown (" + std::to_string(r_type) + ")";
}
static constexpr u32 R_386_NONE = 0;
static constexpr u32 R_386_32 = 1;
static constexpr u32 R_386_PC32 = 2;
static constexpr u32 R_386_GOT32 = 3;
static constexpr u32 R_386_PLT32 = 4;
static constexpr u32 R_386_COPY = 5;
static constexpr u32 R_386_GLOB_DAT = 6;
static constexpr u32 R_386_JUMP_SLOT = 7;
static constexpr u32 R_386_RELATIVE = 8;
static constexpr u32 R_386_GOTOFF = 9;
static constexpr u32 R_386_GOTPC = 10;
static constexpr u32 R_386_32PLT = 11;
static constexpr u32 R_386_TLS_TPOFF = 14;
static constexpr u32 R_386_TLS_IE = 15;
static constexpr u32 R_386_TLS_GOTIE = 16;
static constexpr u32 R_386_TLS_LE = 17;
static constexpr u32 R_386_TLS_GD = 18;
static constexpr u32 R_386_TLS_LDM = 19;
static constexpr u32 R_386_16 = 20;
static constexpr u32 R_386_PC16 = 21;
static constexpr u32 R_386_8 = 22;
static constexpr u32 R_386_PC8 = 23;
static constexpr u32 R_386_TLS_GD_32 = 24;
static constexpr u32 R_386_TLS_GD_PUSH = 25;
static constexpr u32 R_386_TLS_GD_CALL = 26;
static constexpr u32 R_386_TLS_GD_POP = 27;
static constexpr u32 R_386_TLS_LDM_32 = 28;
static constexpr u32 R_386_TLS_LDM_PUSH = 29;
static constexpr u32 R_386_TLS_LDM_CALL = 30;
static constexpr u32 R_386_TLS_LDM_POP = 31;
static constexpr u32 R_386_TLS_LDO_32 = 32;
static constexpr u32 R_386_TLS_IE_32 = 33;
static constexpr u32 R_386_TLS_LE_32 = 34;
static constexpr u32 R_386_TLS_DTPMOD32 = 35;
static constexpr u32 R_386_TLS_DTPOFF32 = 36;
static constexpr u32 R_386_TLS_TPOFF32 = 37;
static constexpr u32 R_386_SIZE32 = 38;
static constexpr u32 R_386_TLS_GOTDESC = 39;
static constexpr u32 R_386_TLS_DESC_CALL = 40;
static constexpr u32 R_386_TLS_DESC = 41;
static constexpr u32 R_386_IRELATIVE = 42;
static constexpr u32 R_386_GOT32X = 43;
template <>
std::string rel_to_string<I386>(u32 r_type) {
switch (r_type) {
case R_386_NONE: return "R_386_NONE";
case R_386_32: return "R_386_32";
case R_386_PC32: return "R_386_PC32";
case R_386_GOT32: return "R_386_GOT32";
case R_386_PLT32: return "R_386_PLT32";
case R_386_COPY: return "R_386_COPY";
case R_386_GLOB_DAT: return "R_386_GLOB_DAT";
case R_386_JUMP_SLOT: return "R_386_JUMP_SLOT";
case R_386_RELATIVE: return "R_386_RELATIVE";
case R_386_GOTOFF: return "R_386_GOTOFF";
case R_386_GOTPC: return "R_386_GOTPC";
case R_386_32PLT: return "R_386_32PLT";
case R_386_TLS_TPOFF: return "R_386_TLS_TPOFF";
case R_386_TLS_IE: return "R_386_TLS_IE";
case R_386_TLS_GOTIE: return "R_386_TLS_GOTIE";
case R_386_TLS_LE: return "R_386_TLS_LE";
case R_386_TLS_GD: return "R_386_TLS_GD";
case R_386_TLS_LDM: return "R_386_TLS_LDM";
case R_386_16: return "R_386_16";
case R_386_PC16: return "R_386_PC16";
case R_386_8: return "R_386_8";
case R_386_PC8: return "R_386_PC8";
case R_386_TLS_GD_32: return "R_386_TLS_GD_32";
case R_386_TLS_GD_PUSH: return "R_386_TLS_GD_PUSH";
case R_386_TLS_GD_CALL: return "R_386_TLS_GD_CALL";
case R_386_TLS_GD_POP: return "R_386_TLS_GD_POP";
case R_386_TLS_LDM_32: return "R_386_TLS_LDM_32";
case R_386_TLS_LDM_PUSH: return "R_386_TLS_LDM_PUSH";
case R_386_TLS_LDM_CALL: return "R_386_TLS_LDM_CALL";
case R_386_TLS_LDM_POP: return "R_386_TLS_LDM_POP";
case R_386_TLS_LDO_32: return "R_386_TLS_LDO_32";
case R_386_TLS_IE_32: return "R_386_TLS_IE_32";
case R_386_TLS_LE_32: return "R_386_TLS_LE_32";
case R_386_TLS_DTPMOD32: return "R_386_TLS_DTPMOD32";
case R_386_TLS_DTPOFF32: return "R_386_TLS_DTPOFF32";
case R_386_TLS_TPOFF32: return "R_386_TLS_TPOFF32";
case R_386_SIZE32: return "R_386_SIZE32";
case R_386_TLS_GOTDESC: return "R_386_TLS_GOTDESC";
case R_386_TLS_DESC_CALL: return "R_386_TLS_DESC_CALL";
case R_386_TLS_DESC: return "R_386_TLS_DESC";
case R_386_IRELATIVE: return "R_386_IRELATIVE";
case R_386_GOT32X: return "R_386_GOT32X";
}
return "unknown (" + std::to_string(r_type) + ")";
}
static constexpr u32 DW_EH_PE_absptr = 0;
static constexpr u32 DW_EH_PE_omit = 0xff;
static constexpr u32 DW_EH_PE_uleb128 = 0x01;
static constexpr u32 DW_EH_PE_udata2 = 0x02;
static constexpr u32 DW_EH_PE_udata4 = 0x03;
static constexpr u32 DW_EH_PE_udata8 = 0x04;
static constexpr u32 DW_EH_PE_signed = 0x08;
static constexpr u32 DW_EH_PE_sleb128 = 0x09;
static constexpr u32 DW_EH_PE_sdata2 = 0x0a;
static constexpr u32 DW_EH_PE_sdata4 = 0x0b;
static constexpr u32 DW_EH_PE_sdata8 = 0x0c;
static constexpr u32 DW_EH_PE_pcrel = 0x10;
static constexpr u32 DW_EH_PE_textrel = 0x20;
static constexpr u32 DW_EH_PE_datarel = 0x30;
static constexpr u32 DW_EH_PE_funcrel = 0x40;
static constexpr u32 DW_EH_PE_aligned = 0x50;
struct Elf64Sym {
bool is_defined() const { return !is_undef(); }
bool is_undef() const { return st_shndx == SHN_UNDEF; }
bool is_abs() const { return st_shndx == SHN_ABS; }
bool is_common() const { return st_shndx == SHN_COMMON; }
bool is_weak() const { return st_bind == STB_WEAK; }
bool is_undef_strong() const {
return st_shndx == SHN_UNDEF && st_bind != STB_WEAK;
}
bool is_undef_weak() const {
return st_shndx == SHN_UNDEF && st_bind == STB_WEAK;
}
u32 st_name;
u8 st_type : 4;
u8 st_bind : 4;
u8 st_visibility : 2;
u16 st_shndx;
u64 st_value;
u64 st_size;
};
struct Elf32Sym {
bool is_defined() const { return !is_undef(); }
bool is_undef() const { return st_shndx == SHN_UNDEF; }
bool is_abs() const { return st_shndx == SHN_ABS; }
bool is_common() const { return st_shndx == SHN_COMMON; }
bool is_weak() const { return st_bind == STB_WEAK; }
bool is_undef_strong() const {
return st_shndx == SHN_UNDEF && st_bind != STB_WEAK;
}
bool is_undef_weak() const {
return st_shndx == SHN_UNDEF && st_bind == STB_WEAK;
}
u32 st_name;
u32 st_value;
u32 st_size;
u8 st_type : 4;
u8 st_bind : 4;
u8 st_visibility : 2;
u16 st_shndx;
};
struct Elf64Shdr {
u32 sh_name;
u32 sh_type;
u64 sh_flags;
u64 sh_addr;
u64 sh_offset;
u64 sh_size;
u32 sh_link;
u32 sh_info;
u64 sh_addralign;
u64 sh_entsize;
};
struct Elf32Shdr {
u32 sh_name;
u32 sh_type;
u32 sh_flags;
u32 sh_addr;
u32 sh_offset;
u32 sh_size;
u32 sh_link;
u32 sh_info;
u32 sh_addralign;
u32 sh_entsize;
};
struct Elf64Ehdr {
u8 e_ident[16];
u16 e_type;
u16 e_machine;
u32 e_version;
u64 e_entry;
u64 e_phoff;
u64 e_shoff;
u32 e_flags;
u16 e_ehsize;
u16 e_phentsize;
u16 e_phnum;
u16 e_shentsize;
u16 e_shnum;
u16 e_shstrndx;
};
struct Elf32Ehdr {
u8 e_ident[16];
u16 e_type;
u16 e_machine;
u32 e_version;
u32 e_entry;
u32 e_phoff;
u32 e_shoff;
u32 e_flags;
u16 e_ehsize;
u16 e_phentsize;
u16 e_phnum;
u16 e_shentsize;
u16 e_shnum;
u16 e_shstrndx;
};
struct Elf64Phdr {
u32 p_type;
u32 p_flags;
u64 p_offset;
u64 p_vaddr;
u64 p_paddr;
u64 p_filesz;
u64 p_memsz;
u64 p_align;
};
struct Elf32Phdr {
u32 p_type;
u32 p_offset;
u32 p_vaddr;
u32 p_paddr;
u32 p_filesz;
u32 p_memsz;
u32 p_flags;
u32 p_align;
};
struct Elf64Rel {
u64 r_offset;
u32 r_type;
u32 r_sym;
};
struct Elf32Rel {
u32 r_offset;
u32 r_type : 8;
u32 r_sym : 24;
};
struct Elf64Rela {
u64 r_offset;
u32 r_type;
u32 r_sym;
i64 r_addend;
};
struct Elf32Rela {
u32 r_offset;
u32 r_type : 8;
u32 r_sym : 24;
i32 r_addend;
};
struct Elf64Dyn {
u64 d_tag;
u64 d_val;
};
struct Elf32Dyn {
u32 d_tag;
u32 d_val;
};
struct Elf64Verneed {
u16 vn_version;
u16 vn_cnt;
u32 vn_file;
u32 vn_aux;
u32 vn_next;
};
struct Elf64Vernaux {
u32 vna_hash;
u16 vna_flags;
u16 vna_other;
u32 vna_name;
u32 vna_next;
};
struct Elf64Verdef {
u16 vd_version;
u16 vd_flags;
u16 vd_ndx;
u16 vd_cnt;
u32 vd_hash;
u32 vd_aux;
u32 vd_next;
};
struct Elf64Verdaux {
u32 vda_name;
u32 vda_next;
};
struct Elf64Chdr {
u32 ch_type;
u32 ch_reserved;
u64 ch_size;
u64 ch_addralign;
};
struct Elf32Chdr {
u32 ch_type;
u32 ch_size;
u32 ch_addralign;
};
struct Elf64Nhdr {
u32 n_namesz;
u32 n_descsz;
u32 n_type;
};
template <typename E> struct ElfSym;
template <typename E> struct ElfShdr;
template <typename E> struct ElfEhdr;
template <typename E> struct ElfPhdr;
template <typename E> struct ElfRel;
template <typename E> struct ElfDyn;
template <typename E> struct ElfVerneed;
template <typename E> struct ElfVernaux;
template <typename E> struct ElfVerdef;
template <typename E> struct ElfVerdaux;
template <typename E> struct ElfChdr;
template <typename E> struct ElfNhdr;
struct X86_64 {
typedef u64 WordTy;
static constexpr u32 R_NONE = R_X86_64_NONE;
static constexpr u32 R_COPY = R_X86_64_COPY;
static constexpr u32 R_GLOB_DAT = R_X86_64_GLOB_DAT;
static constexpr u32 R_JUMP_SLOT = R_X86_64_JUMP_SLOT;
static constexpr u32 R_RELATIVE = R_X86_64_RELATIVE;
static constexpr u32 R_IRELATIVE = R_X86_64_IRELATIVE;
static constexpr u32 R_DTPOFF = R_X86_64_DTPOFF64;
static constexpr u32 R_TPOFF = R_X86_64_TPOFF64;
static constexpr u32 R_DTPMOD = R_X86_64_DTPMOD64;
static constexpr u32 R_TLSDESC = R_X86_64_TLSDESC;
static constexpr u32 wordsize = 8;
static constexpr u32 e_machine = EM_X86_64;
static constexpr u32 plt_size = 16;
static constexpr u32 pltgot_size = 8;
static constexpr bool is_rel = false;
static constexpr bool is_le = true;
};
template <> struct ElfSym<X86_64> : public Elf64Sym {};
template <> struct ElfShdr<X86_64> : public Elf64Shdr {};
template <> struct ElfEhdr<X86_64> : public Elf64Ehdr {};
template <> struct ElfPhdr<X86_64> : public Elf64Phdr {};
template <> struct ElfRel<X86_64> : public Elf64Rela {};
template <> struct ElfDyn<X86_64> : public Elf64Dyn {};
template <> struct ElfVerneed<X86_64> : public Elf64Verneed {};
template <> struct ElfVernaux<X86_64> : public Elf64Vernaux {};
template <> struct ElfVerdef<X86_64> : public Elf64Verdef {};
template <> struct ElfVerdaux<X86_64> : public Elf64Verdaux {};
template <> struct ElfChdr<X86_64> : public Elf64Chdr {};
template <> struct ElfNhdr<X86_64> : public Elf64Nhdr {};
struct I386 {
typedef u32 WordTy;
static constexpr u32 R_NONE = R_386_NONE;
static constexpr u32 R_COPY = R_386_COPY;
static constexpr u32 R_GLOB_DAT = R_386_GLOB_DAT;
static constexpr u32 R_JUMP_SLOT = R_386_JUMP_SLOT;
static constexpr u32 R_RELATIVE = R_386_RELATIVE;
static constexpr u32 R_IRELATIVE = R_386_IRELATIVE;
static constexpr u32 R_DTPOFF = R_386_TLS_DTPOFF32;
static constexpr u32 R_TPOFF = R_386_TLS_TPOFF;
static constexpr u32 R_DTPMOD = R_386_TLS_DTPMOD32;
static constexpr u32 R_TLSDESC = R_386_TLS_DESC;
static constexpr u32 wordsize = 4;
static constexpr u32 e_machine = EM_386;
static constexpr u32 plt_size = 16;
static constexpr u32 pltgot_size = 8;
static constexpr bool is_rel = true;
static constexpr bool is_le = true;
};
template <> struct ElfSym<I386> : public Elf32Sym {};
template <> struct ElfShdr<I386> : public Elf32Shdr {};
template <> struct ElfEhdr<I386> : public Elf32Ehdr {};
template <> struct ElfPhdr<I386> : public Elf32Phdr {};
template <> struct ElfRel<I386> : public Elf32Rel {};
template <> struct ElfDyn<I386> : public Elf32Dyn {};
template <> struct ElfVerneed<I386> : public Elf64Verneed {};
template <> struct ElfVernaux<I386> : public Elf64Vernaux {};
template <> struct ElfVerdef<I386> : public Elf64Verdef {};
template <> struct ElfVerdaux<I386> : public Elf64Verdaux {};
template <> struct ElfChdr<I386> : public Elf32Chdr {};
template <> struct ElfNhdr<I386> : public Elf64Nhdr {};
+105
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@@ -0,0 +1,105 @@
#include "mold.h"
std::string get_current_dir() {
std::string buf(8192, '\0');
getcwd(buf.data(), buf.size());
buf.resize(buf.find_first_of('\0'));
return buf;
}
// Returns the directory part of a given path.
// Returns '.' if path doesn't contain '/'.
std::string_view path_dirname(std::string_view path) {
i64 pos = path.find_last_of('/');
if (pos == path.npos)
return ".";
return path.substr(0, pos);
}
// Returns the filename part of a given path.
// Returns '/' if path reperesents the root directory.
// Returns '.' if path is empty.
std::string_view path_filename(std::string_view path) {
if (path.empty())
return ".";
while (path.ends_with('/'))
path = path.substr(0, path.size() - 2);
if (path.empty())
return "/";
i64 pos = path.find_last_of('/');
if (pos == path.npos)
return path;
return path.substr(pos + 1);
}
// Returns the filename part of a given path without the file
// extension.
std::string_view path_basename(std::string_view path) {
std::string_view name = path_filename(path);
i64 pos = name.find_last_of('.');
if (pos == name.npos)
return name;
return name.substr(0, pos);
}
std::string path_to_absolute(std::string_view path) {
if (path.starts_with('/'))
return std::string(path);
return get_current_dir() + "/" + std::string(path);
}
// Removes redundant '/..' or '/.' from a given path.
// The transformation is done purely by lexical processing.
// This function does not access file system.
std::string path_clean(std::string_view path) {
std::vector<std::string_view> components;
bool is_rooted = path.starts_with('/');
while (!path.empty()) {
size_t pos = path.find('/');
std::string_view elem;
if (pos == path.npos) {
elem = path;
path = "";
} else {
elem = path.substr(0, pos);
path = path.substr(pos + 1);
}
if (elem.empty() || elem == ".")
continue;
if (elem == "..") {
if (components.empty()) {
if (is_rooted)
continue;
components.push_back("..");
continue;
}
if (components.back() == "..")
components.push_back("..");
else
components.pop_back();
continue;
}
components.push_back(elem);
}
std::string ret;
if (is_rooted)
ret = "/";
for (i64 i = 0, end = components.size(); i < end; i++) {
ret += components[i];
if (i != end - 1)
ret += "/";
}
return ret;
}
+192
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@@ -0,0 +1,192 @@
// This file implements a mark-sweep garbage collector for -gc-sections.
// In this algorithm, vertices are sections and edges are relocations.
// Any section that is reachable from a root section is considered alive.
#include "mold.h"
#include <tbb/concurrent_vector.h>
#include <tbb/parallel_for_each.h>
template <typename E>
using Feeder = tbb::parallel_do_feeder<InputSection<E> *>;
template <typename E>
static bool is_init_fini(const InputSection<E> &isec) {
return isec.shdr.sh_type == SHT_INIT_ARRAY ||
isec.shdr.sh_type == SHT_FINI_ARRAY ||
isec.shdr.sh_type == SHT_PREINIT_ARRAY ||
isec.name().starts_with(".ctors") ||
isec.name().starts_with(".dtors") ||
isec.name().starts_with(".init") ||
isec.name().starts_with(".fini");
}
template <typename E>
static bool mark_section(InputSection<E> *isec) {
return isec && isec->is_alive && !isec->is_visited.exchange(true);
}
template <typename E>
static void visit(Context<E> &ctx, InputSection<E> *isec,
Feeder<E> &feeder, i64 depth) {
assert(isec->is_visited);
// A relocation can refer either a section fragment (i.e. a piece of
// string in a mergeable string section) or a symbol. Mark all
// section fragments as alive.
if (isec->rel_fragments)
for (i64 i = 0; isec->rel_fragments[i].idx >= 0; i++)
isec->rel_fragments[i].frag->is_alive = true;
// If this is a text section, .eh_frame may contain records
// describing how to handle exceptions for that function.
// We want to keep associated .eh_frame records.
for (FdeRecord<E> &fde : isec->get_fdes())
for (ElfRel<E> &rel : fde.get_rels().subspan(1))
if (Symbol<E> *sym = isec->file.symbols[rel.r_sym])
if (mark_section(sym->input_section))
feeder.add(sym->input_section);
for (ElfRel<E> &rel : isec->get_rels(ctx)) {
Symbol<E> &sym = *isec->file.symbols[rel.r_sym];
// Symbol can refer either a section fragment or an input section.
// Mark a fragment as alive.
if (SectionFragment<E> *frag = sym.get_frag()) {
frag->is_alive = true;
continue;
}
if (!mark_section(sym.input_section))
continue;
// Mark a section alive. For better performacne, we don't call
// `feeder.add` too often.
if (depth < 3)
visit(ctx, sym.input_section, feeder, depth + 1);
else
feeder.add(sym.input_section);
}
}
template <typename E>
static tbb::concurrent_vector<InputSection<E> *>
collect_root_set(Context<E> &ctx) {
Timer t(ctx, "collect_root_set");
tbb::concurrent_vector<InputSection<E> *> roots;
auto enqueue_section = [&](InputSection<E> *isec) {
if (mark_section(isec))
roots.push_back(isec);
};
auto enqueue_symbol = [&](Symbol<E> *sym) {
if (sym) {
if (SectionFragment<E> *frag = sym->get_frag())
frag->is_alive = true;
else
enqueue_section(sym->input_section);
}
};
// Add sections that are not subject to garbage collection.
tbb::parallel_for_each(ctx.objs, [&](ObjectFile<E> *file) {
for (std::unique_ptr<InputSection<E>> &isec : file->sections) {
if (!isec || !isec->is_alive)
continue;
// -gc-sections discards only SHF_ALLOC sections. If you want to
// reduce the amount of non-memory-mapped segments, you should
// use `strip` command, compile without debug info or use
// -strip-all linker option.
if (!(isec->shdr.sh_flags & SHF_ALLOC))
isec->is_visited = true;
if (is_init_fini(*isec) || is_c_identifier(isec->name()) ||
isec->shdr.sh_type == SHT_NOTE)
enqueue_section(isec.get());
}
});
// Add sections containing exported symbols
tbb::parallel_for_each(ctx.objs, [&](ObjectFile<E> *file) {
for (Symbol<E> *sym : file->symbols)
if (sym->file == file && sym->is_exported)
enqueue_symbol(sym);
});
// Add sections referenced by root symbols.
enqueue_symbol(Symbol<E>::intern(ctx, ctx.arg.entry));
for (std::string_view name : ctx.arg.undefined)
enqueue_symbol(Symbol<E>::intern(ctx, name));
// .eh_frame consists of variable-length records called CIE and FDE
// records, and they are a unit of inclusion or exclusion.
// We just keep all CIEs and everything that are referenced by them.
tbb::parallel_for_each(ctx.objs, [&](ObjectFile<E> *file) {
for (CieRecord<E> &cie : file->cies)
for (ElfRel<E> &rel : cie.get_rels())
enqueue_symbol(file->symbols[rel.r_sym]);
});
return roots;
}
// Mark all reachable sections
template <typename E>
static void mark(Context<E> &ctx,
tbb::concurrent_vector<InputSection<E> *> &roots) {
Timer t(ctx, "mark");
tbb::parallel_do(roots, [&](InputSection<E> *isec, Feeder<E> &feeder) {
visit(ctx, isec, feeder, 0);
});
}
// Remove unreachable sections
template <typename E>
static void sweep(Context<E> &ctx) {
Timer t(ctx, "sweep");
static Counter counter("garbage_sections");
tbb::parallel_for_each(ctx.objs, [&](ObjectFile<E> *file) {
for (i64 i = 0; i < file->sections.size(); i++) {
std::unique_ptr<InputSection<E>> &isec = file->sections[i];
if (isec && isec->is_alive && !isec->is_visited) {
if (ctx.arg.print_gc_sections)
SyncOut(ctx) << "removing unused section " << *isec;
isec->kill();
counter++;
}
}
});
}
// Non-alloc section fragments are not subject of garbage collection.
// This function marks such fragments.
template <typename E>
static void mark_nonalloc_fragments(Context<E> &ctx) {
Timer t(ctx, "mark_nonalloc_fragments");
tbb::parallel_for_each(ctx.objs, [](ObjectFile<E> *file) {
for (SectionFragment<E> *frag : file->fragments)
if (!(frag->output_section.shdr.sh_flags & SHF_ALLOC))
frag->is_alive = true;
});
}
template <typename E>
void gc_sections(Context<E> &ctx) {
Timer t(ctx, "gc");
mark_nonalloc_fragments(ctx);
tbb::concurrent_vector<InputSection<E> *> roots = collect_root_set(ctx);
mark(ctx, roots);
sweep(ctx);
}
template void gc_sections(Context<X86_64> &ctx);
template void gc_sections(Context<I386> &ctx);
Executable
+76
View File
@@ -0,0 +1,76 @@
#!/bin/bash
#
# This test script takes a Gentoo package name and tries to build it
# using mold in a Docker environment. We chose Gentoo Linux as a test
# target, because its source-based package allows us to build programs
# locally and run their test suites without any hassle.
#
# You can get a complete list of Gentoo packages availalbe for testing
# with the following command:
#
# docker run --rm mold-gentoo emerge --color n -s '' | \
# perl -ne 'next unless m!^\*\s+(\S+/\S+)!; print "$1\n"'
if [ "$1" = "" ]; then
echo "Usage: $0 gentoo-package-name"
exit 1
fi
set -x
# Create a Docker image
if ! docker image ls mold-gentoo | grep -q mold-gentoo; then
set -e
cat <<EOF | docker build -t mold-gentoo -
FROM gentoo/stage3
RUN emerge-webrsync
RUN echo 'USE="elogind -systemd corefonts truetype jpeg jpeg2k tiff zstd static-libs binary"' >> /etc/portage/make.conf && \
echo 'ACCEPT_LICENSE="* -@EULA"' >> /etc/portage/make.conf && \
echo 'FEATURES="${FEATURE} noclean nostrip -ipc-sandbox -network-sandbox -pid-sandbox -sandbox"' >> /etc/portage/make.conf
RUN emerge gdb lld vim strace && rm -rf /var/tmp/portage
EOF
set +e
fi
# Build mold as a statically-linked executable
if ! [ -f mold ] || ! ldd mold 2>&1 | grep -q 'not a dynamic executable'; then
make clean
./build-static.sh
fi
git_hash=$(./mold --version | perl -ne '/\((\w+)/; print $1;')
# Build a given package in Docker
build() {
package="$1"
cmd1="ln -sf /mold/mold /usr/x86_64-pc-linux-gnu/bin/ld"
cmd2="MAKEOPTS=-j8 emerge --onlydeps $package"
cmd3="MAKEOPTS=-j8 FEATURES=test emerge $package"
filename=`echo "$package" | sed 's!/!_!g'`
docker="docker run --rm --cap-add=SYS_PTRACE -v `pwd`:/mold mold-gentoo timeout -v -k 15s 1h"
dir=gentoo/$git_hash
mkdir -p $dir/success $dir/failure
$docker nice -n 19 bash -c "$cmd1 && $cmd2 && $cmd3" >& $dir/$filename.mold
if [ $? = 0 ]; then
mv $dir/$filename.mold $dir/success
else
mv $dir/$filename.mold $dir/failure
fi
$docker nice -n 19 bash -c "$cmd2 && $cmd3" >& $dir/$filename.ld
if [ $? = 0 ]; then
mv $dir/$filename.ld $dir/success
else
mv $dir/$filename.ld $dir/failure
fi
}
if [ "$1" = dev-libs/concurrencykit ]; then
echo "Skipping known broken package: $1"
exit 0
fi
# Build a package
build "$1"
+151 -223
View File
@@ -35,41 +35,25 @@
// This problem boils down to one in graph theory. Input to ICF can be
// considered as a directed graph in which vertices are sections and edges
// are relocations. Vertices have labels (section contents, etc.), and so
// are edges (relocation offsets, etc.). Two vertices are considered
// identical if and only if the (possibly infinite) their unfoldings into
// regular trees are equal. Given this formulation, we want to find as
// many identical vertices as possible.
// are edges (relocation offsets, etc.). Given this formulation, we want to
// find as many isomorphic subgraphs as possible.
//
// Just like a lot of problems with graph, this problem doesn't have a
// straightforward "optimal" solution, and we need to resort to heuristics.
// Solving such problem is computationally intensive, but mold is quite fast.
// For Chromium, mold's ICF finishes in less than 1 second with 20 threads.
// This is contrary to lld and gold, which take about 5 and 50 seconds to
// run ICF under the same condition, respectively.
//
// mold approaches this problem by hashing program trees with increasing depth
// on each iteration.
// For example, when we start, we only hash individual functions with
// their call into other functions omitted. From the second iteration, we
// put the function they call into the hash by appending the hash of those
// functions from the previous iteration. This means that the nth iteration
// hashes call chain up to (n-1) levels deep.
// We use a cryptographic hash function, so the unique number of hashes will
// only monotonically increase as we take into account of deeper trees with
// iterations (otherwise, that means we have found a hash collision). We stop
// when the unique number of hashes stop increasing; this is based on the fact
// that once we observe an iteration with the same amount of unique hashes as
// the previous iteration, it will remain unchanged for further iterations.
// This is provable, but here we omit the proof for brevity.
//
// When compared to other approaches, mold's approach has a relatively cheaper
// cost per iteration, and as a bonus, is highly parallelizable.
// For Chromium, mold's ICF finishes in less than 1 second with 20 threads,
// whereas lld takes 5 seconds and gold takes 50 seconds under the same
// conditions.
// mold's ICF is faster because we are using a better algorithm.
// It's actually me who developed and implemented the lld's ICF algorithm,
// and I can say that mold's algorithm is better than that in all aspects.
// It scales better for number of available cores, require less overall
// computation, and has a smaller working set. So, it's better with a single
// thread and even better with multiple threads.
#include "mold.h"
#include "../lib/siphash.h"
#include <array>
#include <cstdio>
#include <fstream>
#include <openssl/sha.h>
#include <tbb/concurrent_unordered_map.h>
#include <tbb/concurrent_vector.h>
#include <tbb/enumerable_thread_specific.h>
@@ -77,72 +61,66 @@
#include <tbb/parallel_for_each.h>
#include <tbb/parallel_sort.h>
static constexpr int64_t HASH_SIZE = 16;
static constexpr i64 HASH_SIZE = 16;
using Digest = std::array<uint8_t, HASH_SIZE>;
typedef std::array<u8, HASH_SIZE> Digest;
namespace std {
template <> struct hash<Digest> {
namespace tbb {
template<> struct tbb_hash<Digest> {
size_t operator()(const Digest &k) const {
static_assert(sizeof(size_t) <= HASH_SIZE);
size_t val;
memcpy(&val, k.data(), sizeof(size_t));
return val;
return *(i64 *)&k[0];
}
};
}
namespace mold {
static u8 hmac_key[16];
template <typename E>
static void uniquify_cies(Context<E> &ctx) {
Timer t(ctx, "uniquify_cies");
std::vector<CieRecord<E> *> cies;
auto find = [&](CieRecord<E> &cie) -> i64 {
for (i64 i = 0; i < cies.size(); i++)
if (cie_equals(cie, *cies[i]))
return i;
return -1;
};
for (ObjectFile<E> *file : ctx.objs) {
for (CieRecord<E> &cie : file->cies) {
if (i64 idx = find(cie); idx != -1) {
cie.icf_idx = idx;
} else {
cie.icf_idx = cies.size();
cies.push_back(&cie);
for (i64 i = 0; i < cies.size(); i++) {
if (cie.equals(*cies[i])) {
cie.icf_idx = i;
goto found;
}
}
cie.icf_idx = cies.size();
cies.push_back(&cie);
found:;
}
}
}
template <typename E>
static bool is_eligible(Context<E> &ctx, InputSection<E> &isec) {
const ElfShdr<E> &shdr = isec.shdr();
static bool is_eligible(InputSection<E> &isec) {
const ElfShdr<E> &shdr = isec.shdr;
std::string_view name = isec.name();
if (shdr.sh_size == 0 || !(shdr.sh_flags & SHF_ALLOC) ||
shdr.sh_type == SHT_NOBITS || is_c_identifier(isec.name))
return false;
bool is_alloc = (shdr.sh_flags & SHF_ALLOC);
bool is_executable = (shdr.sh_flags & SHF_EXECINSTR);
bool is_relro = (name == ".data.rel.ro" ||
name.starts_with(".data.rel.ro."));
bool is_readonly = !(shdr.sh_flags & SHF_WRITE) || is_relro;
bool is_bss = (shdr.sh_type == SHT_NOBITS);
bool is_empty = (shdr.sh_size == 0);
bool is_init = (shdr.sh_type == SHT_INIT_ARRAY || name == ".init");
bool is_fini = (shdr.sh_type == SHT_FINI_ARRAY || name == ".fini");
bool is_enumerable = is_c_identifier(name);
if (shdr.sh_flags & SHF_EXECINSTR)
return (ctx.arg.icf_all || !isec.address_taken) &&
isec.name != ".init" && isec.name != ".fini";
return is_alloc && is_executable && is_readonly && !is_bss &&
!is_empty && !is_init && !is_fini && !is_enumerable;
}
// .gcc_except_table contains a compiler-generated table. Pointer
// equality for the section is not significant because only the C++
// exception handling code will use the table at runtime.
if (isec.name == ".gcc_except_table" ||
isec.name.starts_with(".gcc_except_table."))
return true;
static Digest digest_final(SHA256_CTX &sha) {
u8 buf[SHA256_SIZE];
int res = SHA256_Final(buf, &sha);
assert(res == 1);
bool is_readonly = !(shdr.sh_flags & SHF_WRITE);
bool is_relro = isec.name.starts_with(".data.rel.ro");
return (ctx.arg.ignore_data_address_equality || !isec.address_taken) &&
(is_readonly || is_relro);
Digest digest;
memcpy(digest.data(), buf, HASH_SIZE);
return digest;
}
template <typename E>
@@ -151,18 +129,22 @@ static bool is_leaf(Context<E> &ctx, InputSection<E> &isec) {
return false;
for (FdeRecord<E> &fde : isec.get_fdes())
if (fde.get_rels(isec.file).size() > 1)
if (fde.get_rels().size() > 1)
return false;
return true;
}
static u64 combine_hash(u64 a, u64 b) {
return a ^ (b + 0x9e3779b9 + (a << 6) + (a >> 2));
}
template <typename E>
struct LeafHasher {
size_t operator()(InputSection<E> *isec) const {
size_t operator()(const InputSection<E> *isec) const {
u64 h = hash_string(isec->contents);
for (FdeRecord<E> &fde : isec->get_fdes()) {
u64 h2 = hash_string(fde.get_contents(isec->file).substr(8));
u64 h2 = hash_string(fde.get_contents().substr(8));
h = combine_hash(h, h2);
}
return h;
@@ -171,7 +153,7 @@ struct LeafHasher {
template <typename E>
struct LeafEq {
bool operator()(InputSection<E> *a, InputSection<E> *b) const {
bool operator()(const InputSection<E> *a, const InputSection<E> *b) const {
if (a->contents != b->contents)
return false;
@@ -182,15 +164,12 @@ struct LeafEq {
return false;
for (i64 i = 0; i < x.size(); i++)
if (x[i].get_contents(a->file).substr(8) !=
y[i].get_contents(b->file).substr(8))
if (x[i].get_contents().substr(8) != y[i].get_contents().substr(8))
return false;
return true;
}
};
// Early merge of leaf nodes, which can be processed without constructing the
// entire graph. This reduces the vertex count and improves memory efficiency.
template <typename E>
static void merge_leaf_nodes(Context<E> &ctx) {
Timer t(ctx, "merge_leaf_nodes");
@@ -199,7 +178,7 @@ static void merge_leaf_nodes(Context<E> &ctx) {
static Counter non_eligible("icf_non_eligibles");
static Counter leaf("icf_leaf_nodes");
tbb::concurrent_unordered_map<InputSection<E> *, Atomic<InputSection<E> *>,
tbb::concurrent_unordered_map<InputSection<E> *, InputSection<E> *,
LeafHasher<E>, LeafEq<E>> map;
tbb::parallel_for((i64)0, (i64)ctx.objs.size(), [&](i64 i) {
@@ -207,7 +186,7 @@ static void merge_leaf_nodes(Context<E> &ctx) {
if (!isec || !isec->is_alive)
continue;
if (!is_eligible(ctx, *isec)) {
if (!is_eligible(*isec)) {
non_eligible++;
continue;
}
@@ -216,11 +195,8 @@ static void merge_leaf_nodes(Context<E> &ctx) {
leaf++;
isec->icf_leaf = true;
auto [it, inserted] = map.insert({isec.get(), isec.get()});
if (!inserted) {
InputSection<E> *isec2 = it->second.load();
while (isec->get_priority() < isec2->get_priority() &&
!it->second.compare_exchange_strong(isec2, isec.get()));
}
if (!inserted && isec->get_priority() < it->second->get_priority())
it->second = isec.get();
} else {
eligible++;
isec->icf_eligible = true;
@@ -241,26 +217,29 @@ static void merge_leaf_nodes(Context<E> &ctx) {
template <typename E>
static Digest compute_digest(Context<E> &ctx, InputSection<E> &isec) {
SipHash13_128 hasher(hmac_key);
SHA256_CTX sha;
SHA256_Init(&sha);
u8 *buf = (u8 *)isec.contents.data();
auto hash = [&](auto val) {
hasher.update((u8 *)&val, sizeof(val));
SHA256_Update(&sha, &val, sizeof(val));
};
auto hash_string = [&](std::string_view str) {
hash(str.size());
hasher.update((u8 *)str.data(), str.size());
SHA256_Update(&sha, str.data(), str.size());
};
auto hash_symbol = [&](Symbol<E> &sym) {
InputSection<E> *isec = sym.get_input_section();
InputSection<E> *isec = sym.input_section;
if (!sym.file || sym.is_imported) {
if (!sym.file) {
hash('1');
hash((u64)&sym);
} else if (SectionFragment<E> *frag = sym.get_frag()) {
hash('2');
hash((u64)frag);
hash_string(frag->data);
} else if (!isec) {
hash('3');
} else if (isec->leader) {
@@ -276,38 +255,46 @@ static Digest compute_digest(Context<E> &ctx, InputSection<E> &isec) {
};
hash_string(isec.contents);
hash(isec.shdr().sh_flags);
hash(isec.shdr.sh_flags);
hash(isec.get_fdes().size());
hash(isec.get_rels(ctx).size());
for (FdeRecord<E> &fde : isec.get_fdes()) {
hash(isec.file.cies[fde.cie_idx].icf_idx);
hash(fde.cie->icf_idx);
// Bytes 0 to 4 contain the length of this record, and
// bytes 4 to 8 contain an offset to CIE.
hash_string(fde.get_contents(isec.file).substr(8));
hash_string(fde.get_contents().substr(8));
hash(fde.get_rels(isec.file).size());
hash(fde.get_rels().size());
for (const ElfRel<E> &rel : fde.get_rels(isec.file).subspan(1)) {
for (ElfRel<E> &rel : fde.get_rels().subspan(1)) {
hash_symbol(*isec.file.symbols[rel.r_sym]);
hash(rel.r_type);
hash(rel.r_offset - fde.input_offset);
hash(get_addend(isec.file.cies[fde.cie_idx].input_section, rel));
hash(fde.cie->input_section.get_addend(rel));
}
}
i64 frag_idx = 0;
for (i64 i = 0; i < isec.get_rels(ctx).size(); i++) {
const ElfRel<E> &rel = isec.get_rels(ctx)[i];
ElfRel<E> &rel = isec.get_rels(ctx)[i];
hash(rel.r_offset);
hash(rel.r_type);
hash(get_addend(isec, rel));
hash_symbol(*isec.file.symbols[rel.r_sym]);
hash(isec.get_addend(rel));
if (isec.rel_fragments && isec.rel_fragments[frag_idx].idx == i) {
SectionFragmentRef<E> &ref = isec.rel_fragments[frag_idx++];
hash('a');
isec.get_addend(rel);
hash_string(ref.frag->data);
} else {
hash_symbol(*isec.file.symbols[rel.r_sym]);
}
}
Digest digest;
hasher.finish(digest.data());
return digest;
return digest_final(sha);
}
template <typename E>
@@ -357,9 +344,6 @@ compute_digests(Context<E> &ctx, std::span<InputSection<E> *> sections) {
return digests;
}
// Build a graph, treating every function as a vertex and every function call
// as an edge. See the description at the top for a more detailed formulation.
// We use u32 indices here to improve cache locality.
template <typename E>
static void gather_edges(Context<E> &ctx,
std::span<InputSection<E> *> sections,
@@ -367,23 +351,24 @@ static void gather_edges(Context<E> &ctx,
std::vector<u32> &edge_indices) {
Timer t(ctx, "gather_edges");
if (sections.empty())
return;
std::vector<i64> num_edges(sections.size());
edge_indices.resize(sections.size());
tbb::parallel_for((i64)0, (i64)sections.size(), [&](i64 i) {
InputSection<E> &isec = *sections[i];
assert(isec.icf_eligible);
i64 frag_idx = 0;
for (i64 j = 0; j < isec.get_rels(ctx).size(); j++) {
const ElfRel<E> &rel = isec.get_rels(ctx)[j];
Symbol<E> &sym = *isec.file.symbols[rel.r_sym];
if (!sym.get_frag())
if (InputSection<E> *isec = sym.get_input_section())
if (isec->icf_eligible)
num_edges[i]++;
if (isec.rel_fragments && isec.rel_fragments[frag_idx].idx == j) {
frag_idx++;
} else {
ElfRel<E> &rel = isec.get_rels(ctx)[j];
Symbol<E> &sym = *isec.file.symbols[rel.r_sym];
if (!sym.get_frag() && sym.input_section &&
sym.input_section->icf_eligible)
num_edges[i]++;
}
}
});
@@ -394,22 +379,26 @@ static void gather_edges(Context<E> &ctx,
tbb::parallel_for((i64)0, (i64)num_edges.size(), [&](i64 i) {
InputSection<E> &isec = *sections[i];
i64 frag_idx = 0;
i64 idx = edge_indices[i];
for (ElfRel<E> &rel : isec.get_rels(ctx)) {
Symbol<E> &sym = *isec.file.symbols[rel.r_sym];
if (InputSection<E> *isec = sym.get_input_section())
if (isec->icf_eligible)
edges[idx++] = isec->icf_idx;
}
for (i64 j = 0; j < isec.get_rels(ctx).size(); j++) {
if (isec.rel_fragments && isec.rel_fragments[frag_idx].idx == j) {
frag_idx++;
ElfRel<E> &rel = isec.get_rels(ctx)[j];
Symbol<E> &sym = *isec.file.symbols[rel.r_sym];
if (!sym.get_frag() && sym.input_section &&
sym.input_section->icf_eligible)
edges[idx++] = sym.input_section->icf_idx;
}
}
});
}
template <typename E>
static i64 propagate(std::span<std::vector<Digest>> digests,
std::span<u32> edges, std::span<u32> edge_indices,
bool &slot, std::span<u8> converged,
tbb::affinity_partitioner &ap) {
bool &slot, tbb::affinity_partitioner &ap) {
static Counter round("icf_round");
round++;
@@ -417,27 +406,23 @@ static i64 propagate(std::span<std::vector<Digest>> digests,
tbb::enumerable_thread_specific<i64> changed;
tbb::parallel_for((i64)0, num_digests, [&](i64 i) {
if (converged[i])
if (digests[slot][i] == digests[!slot][i])
return;
SipHash13_128 hasher(hmac_key);
hasher.update(digests[2][i].data(), HASH_SIZE);
SHA256_CTX sha;
SHA256_Init(&sha);
SHA256_Update(&sha, digests[2][i].data(), HASH_SIZE);
i64 begin = edge_indices[i];
i64 end = (i + 1 == num_digests) ? edges.size() : edge_indices[i + 1];
for (i64 j : edges.subspan(begin, end - begin))
hasher.update(digests[slot][j].data(), HASH_SIZE);
for (i64 j = begin; j < end; j++)
SHA256_Update(&sha, digests[slot][edges[j]].data(), HASH_SIZE);
hasher.finish(digests[!slot][i].data());
digests[!slot][i] = digest_final(sha);
if (digests[slot][i] == digests[!slot][i]) {
// This node has converged. Skip further iterations as it will
// yield the same hash.
converged[i] = true;
} else {
if (digests[slot][i] != digests[!slot][i])
changed.local()++;
}
}, ap);
slot = !slot;
@@ -475,45 +460,33 @@ static void print_icf_sections(Context<E> &ctx) {
});
tbb::parallel_sort(leaders.begin(), leaders.end(),
[](InputSection<E> *a, InputSection<E> *b) {
[&](InputSection<E> *a, InputSection<E> *b) {
return a->get_priority() < b->get_priority();
});
std::ostream *out = &std::cout;
std::ofstream file;
std::string &path = ctx.arg.print_icf_sections;
if (path != "-") {
file.open(path);
if (file.fail())
Fatal(ctx) << "--print-icf-sections: cannot open " << path << ": "
<< errno_string();
out = &file;
}
i64 saved_bytes = 0;
for (InputSection<E> *leader : leaders) {
auto [begin, end] = map.equal_range(leader);
if (begin != end) {
*out << "selected section " << *leader << '\n';
for (auto it = begin; it != end; it++) {
*out << " removing identical section " << *it->second << '\n';
saved_bytes += leader->contents.size();
}
if (begin == end)
continue;
SyncOut(ctx) << "selected section " << *leader;
i64 n = 0;
for (auto it = begin; it != end; it++) {
SyncOut(ctx) << " removing identical section " << *it->second;
n++;
}
saved_bytes += leader->contents.size() * n;
}
*out << "ICF saved " << saved_bytes << " bytes\n";
SyncOut(ctx) << "ICF saved " << saved_bytes << " bytes";
}
template <typename E>
void icf_sections(Context<E> &ctx) {
Timer t(ctx, "icf");
if (ctx.objs.empty())
return;
get_random_bytes(hmac_key, sizeof(hmac_key));
uniquify_cies(ctx);
merge_leaf_nodes(ctx);
@@ -521,15 +494,6 @@ void icf_sections(Context<E> &ctx) {
// Prepare for the propagation rounds.
std::vector<InputSection<E> *> sections = gather_sections(ctx);
// We allocate 3 arrays to store hashes for each vertex.
//
// Index 0 and 1 are used for tree hashes from the previous
// iteration and the current iteration. They switch roles every
// iteration. See `slot` below.
//
// Index 2 stores the initial, single-vertex hash. This is combined
// with hashes from the connected vertices to form the tree hash
// described above.
std::vector<std::vector<Digest>> digests(3);
digests[0] = compute_digests<E>(ctx, sections);
digests[1].resize(digests[0].size());
@@ -539,7 +503,6 @@ void icf_sections(Context<E> &ctx) {
std::vector<u32> edge_indices;
gather_edges<E>(ctx, sections, edges, edge_indices);
std::vector<u8> converged(digests[0].size());
bool slot = 0;
// Execute the propagation rounds until convergence is obtained.
@@ -547,33 +510,18 @@ void icf_sections(Context<E> &ctx) {
Timer t(ctx, "propagate");
tbb::affinity_partitioner ap;
// A cheap test that the graph hasn't converged yet.
// The loop after this one uses a strict condition, but it's expensive
// as it requires sorting the entire hash collection.
//
// For nodes that have a cycle in downstream (i.e. recursive
// functions and functions that calls recursive functions) will always
// change with the iterations. Nodes that doesn't (i.e. non-recursive
// functions) will stop changing as soon as the propagation depth reaches
// the call tree depth.
// Here, we test whether we have reached sufficient depth for the latter,
// which is a necessary (but not sufficient) condition for convergence.
i64 num_changed = -1;
for (;;) {
i64 n = propagate<E>(digests, edges, edge_indices, slot, converged, ap);
i64 n = propagate<E>(digests, edges, edge_indices, slot, ap);
if (n == num_changed)
break;
num_changed = n;
}
// Run the pass until the unique number of hashes stop increasing, at which
// point we have achieved convergence (proof omitted for brevity).
i64 num_classes = -1;
for (;;) {
// count_num_classes requires sorting which is O(n log n), so do a little
// more work beforehand to amortize that log factor.
for (i64 i = 0; i < 10; i++)
propagate<E>(digests, edges, edge_indices, slot, converged, ap);
propagate<E>(digests, edges, edge_indices, slot, ap);
i64 n = count_num_classes<E>(digests[slot], ap);
if (n == num_classes)
@@ -582,23 +530,18 @@ void icf_sections(Context<E> &ctx) {
}
}
// Group sections by hash values.
// Group sections by SHA digest.
{
Timer t(ctx, "group");
auto *map =
new tbb::concurrent_unordered_map<Digest, Atomic<InputSection<E> *>>;
auto *map = new tbb::concurrent_unordered_map<Digest, InputSection<E> *>;
std::span<Digest> digest = digests[slot];
tbb::parallel_for((i64)0, (i64)sections.size(), [&](i64 i) {
InputSection<E> *isec = sections[i];
auto [it, inserted] = map->insert({digest[i], isec});
if (!inserted) {
InputSection<E> *isec2 = it->second.load();
while (isec->get_priority() < isec2->get_priority() &&
!it->second.compare_exchange_strong(isec2, isec));
}
if (!inserted && isec->get_priority() < it->second->get_priority())
it->second = isec;
});
tbb::parallel_for((i64)0, (i64)sections.size(), [&](i64 i) {
@@ -608,43 +551,28 @@ void icf_sections(Context<E> &ctx) {
});
// Since free'ing the map is slow, postpone it.
ctx.on_exit.push_back([=] { delete map; });
ctx.on_exit.push_back([=]() { delete map; });
}
if (!ctx.arg.print_icf_sections.empty())
if (ctx.arg.print_icf_sections)
print_icf_sections(ctx);
// Update alignment of leaders.
// Re-assign input sections to symbols.
{
Timer t(ctx, "update_alignment");
Timer t(ctx, "reassign");
tbb::parallel_for_each(ctx.objs, [](ObjectFile<E> *file) {
for (std::unique_ptr<InputSection<E>> &isec : file->sections) {
if (isec && isec->is_alive && isec->leader && isec->leader != isec.get()) {
update_maximum(isec->leader->p2align, isec->p2align);
}
}
});
}
// Eliminate duplicate sections.
// Symbols pointing to eliminated sections will be redirected on the fly when
// exporting to the symtab.
{
Timer t(ctx, "sweep");
static Counter eliminated("icf_eliminated");
tbb::parallel_for_each(ctx.objs, [](ObjectFile<E> *file) {
for (std::unique_ptr<InputSection<E>> &isec : file->sections) {
if (isec && isec->is_alive && isec->icf_removed()) {
for (Symbol<E> *sym : file->symbols) {
if (sym->file != file)
continue;
InputSection<E> *isec = sym->input_section;
if (isec && isec->leader && isec->leader != isec) {
sym->input_section = isec->leader;
isec->kill();
eliminated++;
}
}
});
}
}
using E = MOLD_TARGET;
template void icf_sections(Context<E> &ctx);
} // namespace mold
template void icf_sections(Context<X86_64> &ctx);
template void icf_sections(Context<I386> &ctx);
+154
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@@ -0,0 +1,154 @@
#include "mold.h"
#include <limits>
template <typename E>
InputSection<E>::InputSection(Context<E> &ctx, ObjectFile<E> &file,
const ElfShdr<E> &shdr, std::string_view name,
std::string_view contents, i64 section_idx)
: file(file), shdr(shdr), nameptr(name.data()), namelen(name.size()),
contents(contents), section_idx(section_idx) {
// As a special case, we want to map .ctors and .dtors to
// .init_array and .fini_array, respectively. However, old CRT
// object files are not compatible with this translation, so we need
// to keep them as-is if a section came from crtbegin.o or crtend.o.
//
// Yeah, this is an ugly hack, but the fundamental problem is that
// we have two different mechanism, ctors/dtors and init_array/fini_array
// for the same purpose. The latter was introduced to replace the
// former, but as it is often the case, the former still lingers
// around, so we need to keep this code to conver the old mechanism
// to the new one.
std::string_view stem = path_filename(file.filename);
if (stem != "crtbegin.o" && stem != "crtend.o" &&
stem != "crtbeginS.o" && stem != "crtendS.o") {
if (name == ".ctors" || name.starts_with(".ctors."))
name = ".init_array";
else if (name == ".dtors" || name.starts_with(".dtors."))
name = ".fini_array";
}
output_section =
OutputSection<E>::get_instance(ctx, name, shdr.sh_type, shdr.sh_flags);
}
template <typename E>
void InputSection<E>::write_to(Context<E> &ctx, u8 *buf) {
if (shdr.sh_type == SHT_NOBITS || shdr.sh_size == 0)
return;
// Copy data
memcpy(buf, contents.data(), contents.size());
// Apply relocations
if (shdr.sh_flags & SHF_ALLOC)
apply_reloc_alloc(ctx, buf);
else
apply_reloc_nonalloc(ctx, buf);
// As a special case, .ctors and .dtors section contents are
// reversed. These sections are now obsolete and mapped to
// .init_array and .fini_array, but they have to be reversed to
// maintain the original semantics.
bool init_fini = output_section->name == ".init_array" ||
output_section->name == ".fini_array";
bool ctors_dtors = name().starts_with(".ctors") ||
name().starts_with(".dtors");
if (init_fini && ctors_dtors)
std::reverse((typename E::WordTy *)buf,
(typename E::WordTy *)(buf + shdr.sh_size));
}
template <typename E>
static i64 get_output_type(Context<E> &ctx) {
if (ctx.arg.shared)
return 0;
if (ctx.arg.pie)
return 1;
return 2;
}
template <typename E>
static i64 get_sym_type(Context<E> &ctx, Symbol<E> &sym) {
if (sym.is_absolute(ctx))
return 0;
if (!sym.is_imported)
return 1;
if (sym.get_type() != STT_FUNC)
return 2;
return 3;
}
template <typename E>
void InputSection<E>::dispatch(Context<E> &ctx, Action table[3][4],
u16 rel_type, i64 i) {
std::span<ElfRel<E>> rels = get_rels(ctx);
const ElfRel<E> &rel = rels[i];
Symbol<E> &sym = *file.symbols[rel.r_sym];
bool is_writable = (shdr.sh_flags & SHF_WRITE);
Action action = table[get_output_type(ctx)][get_sym_type(ctx, sym)];
switch (action) {
case NONE:
rel_types[i] = rel_type;
return;
case ERROR:
break;
case COPYREL:
if (!ctx.arg.z_copyreloc && !sym.esym().is_undef_weak())
break;
if (sym.esym().st_visibility == STV_PROTECTED)
Error(ctx) << *this << ": cannot make copy relocation for "
<< " protected symbol '" << sym << "', defined in "
<< *sym.file;
sym.flags |= NEEDS_COPYREL;
rel_types[i] = rel_type;
return;
case PLT:
sym.flags |= NEEDS_PLT;
rel_types[i] = rel_type;
return;
case DYNREL:
if (!is_writable) {
if (ctx.arg.z_text)
break;
ctx.has_textrel = true;
}
sym.flags |= NEEDS_DYNSYM;
rel_types[i] = R_DYN;
file.num_dynrel++;
return;
case BASEREL:
if (!is_writable) {
if (ctx.arg.z_text)
break;
ctx.has_textrel = true;
}
rel_types[i] = R_BASEREL;
file.num_dynrel++;
return;
default:
unreachable(ctx);
}
Error(ctx) << *this << ": " << rel_to_string<E>(rel.r_type)
<< " relocation against symbol `" << sym
<< "' can not be used; recompile with -fPIE";
}
template <typename E>
void InputSection<E>::report_undef(Context<E> &ctx, Symbol<E> &sym) {
switch (ctx.arg.unresolved_symbols) {
case UnresolvedKind::ERROR:
Error(ctx) << "undefined symbol: " << file << ": " << sym;
break;
case UnresolvedKind::WARN:
Warn(ctx) << "undefined symbol: " << file << ": " << sym;
break;
case UnresolvedKind::IGNORE:
break;
}
}
template class InputSection<X86_64>;
template class InputSection<I386>;
-56
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@@ -1,56 +0,0 @@
#!/bin/sh
# This script installs binary packages needed to build mold.
# Feel free to send me a PR if your OS is not on this list.
set -e
. /etc/os-release
set -x
case "$ID" in
ubuntu | pop | linuxmint | debian | raspbian | neon | zorin)
apt-get update
apt-get install -y cmake gcc g++ clang gdb
;;
fedora | fedora-* | amzn | rhel | centos)
dnf install -y gcc-c++ cmake glibc-static libstdc++-static diffutils util-linux tar
;;
rocky | ol)
dnf install -y gcc-c++ cmake diffutils util-linux
;;
opensuse-*)
zypper install -y make cmake gcc-c++ glibc-devel-static tar diffutils util-linux gawk
;;
gentoo)
emerge-webrsync
FEATURES='getbinpkg binpkg-request-signature' emerge dev-build/cmake
;;
arch | archarm | artix | endeavouros | manjaro | cachyos)
pacman -Sy --needed --noconfirm base-devel cmake util-linux
;;
void)
xbps-install -Sy xbps bash make cmake gcc tar diffutils util-linux
;;
alpine)
apk update
apk add bash make linux-headers cmake gcc g++
;;
clear-linux-os)
swupd update
swupd bundle-add c-basic diffutils
;;
almalinux)
dnf install -y gcc-toolset-13-gcc-c++ gcc-toolset-13-libstdc++-devel cmake diffutils
;;
altlinux)
apt-get update
apt-get install -y gcc-c++ make cmake ctest diffutils util-linux
;;
freebsd)
pkg update
pkg install -y cmake bash binutils gcc
;;
*)
echo "Error: don't know anything about build dependencies on $ID-$VERSION_ID"
exit 1
esac
-19
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@@ -1,19 +0,0 @@
#!/bin/bash
set -e
. /etc/os-release
set -x
# This script install packages for -DMOLD_ENABLE_QEMU_TESTS=1
# to enable cross-target tests.
#
# Feel free to send me a PR if your OS is not on this list.
case "$ID" in
ubuntu | pop | linuxmint | debian | raspbian)
apt-get install -y qemu-user {gcc,g++}-{i686,aarch64,riscv64,powerpc,powerpc64,powerpc64le,s390x,sparc64,m68k,sh4}-linux-gnu {gcc,g++}-arm-linux-gnueabihf
;;
*)
echo "Error: don't know anything about build dependencies on $ID-$VERSION_ID"
exit 1
esac
-132
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@@ -1,132 +0,0 @@
// This file implements the Aho-Corasick algorithm to search multiple
// strings within an input string simultaneously. It is essentially a
// trie with additional links. For details, see
// https://en.wikipedia.org/wiki/Aho-Corasick_algorithm.
//
// We use it for simple glob patterns in version scripts or dynamic
// list files. Here are some examples of glob patterns:
//
// qt_private_api_tag*
// *16QAccessibleCache*
// *32QAbstractFileIconProviderPrivate*
// *17QPixmapIconEngine*
//
// Aho-Corasick can do only substring search, so it cannot handle
// complex glob patterns such as `*foo*bar*`. We handle such patterns
// with the Glob class.
#include "lib.h"
#include <queue>
namespace mold {
bool AhoCorasick::can_handle(std::string_view pat) {
if (pat.starts_with('*'))
pat.remove_prefix(1);
if (pat.ends_with('*'))
pat.remove_suffix(1);
return pat.find_first_of("*?[") == pat.npos;
}
i64 AhoCorasick::find(std::string_view str) {
if (nodes.empty())
return -1;
i64 idx = 0;
i64 val = -1;
auto walk = [&](u8 c) {
for (i64 j = idx; j != -1; j = nodes[j].suffix_link) {
i64 child = nodes[j].children[c];
if (child != -1) {
idx = child;
val = std::max(val, nodes[child].value);
return;
}
}
idx = 0;
};
walk('\0');
for (u8 c : str)
walk(c);
walk('\0');
return val;
}
bool AhoCorasick::add(std::string_view pat, i64 val) {
assert(can_handle(pat));
if (nodes.empty())
nodes.resize(1);
i64 idx = 0;
auto walk = [&](u8 c) {
if (nodes[idx].children[c] == -1) {
nodes[idx].children[c] = nodes.size();
nodes.resize(nodes.size() + 1);
}
idx = nodes[idx].children[c];
};
// We handle "foo" as if "\0foo\0", "*foo" as if "foo\0", "foo*" as
// if "\0foo", and "*foo*" as if "foo". Aho-Corasick can do only
// substring matching, so we use \0 as a beginning/end-of-string
// markers.
if (!pat.starts_with('*'))
walk('\0');
for (u8 c : pat)
if (c != '*')
walk(c);
if (!pat.ends_with('*'))
walk('\0');
nodes[idx].value = std::max(nodes[idx].value, val);
return true;
}
void AhoCorasick::compile() {
if (nodes.empty())
return;
fix_suffix_links(0);
fix_values();
}
void AhoCorasick::fix_suffix_links(i64 idx) {
for (i64 i = 0; i < 256; i++) {
i64 child = nodes[idx].children[i];
if (child == -1)
continue;
i64 j = nodes[idx].suffix_link;
for (; j != -1; j = nodes[j].suffix_link) {
if (nodes[j].children[i] != -1) {
nodes[child].suffix_link = j;
break;
}
}
if (j == -1)
nodes[child].suffix_link = 0;
fix_suffix_links(child);
}
}
void AhoCorasick::fix_values() {
std::queue<i64> queue;
queue.push(0);
do {
i64 idx = queue.front();
queue.pop();
for (i64 child : nodes[idx].children) {
if (child != -1) {
i64 suffix = nodes[child].suffix_link;
nodes[child].value = std::max(nodes[child].value, nodes[suffix].value);
queue.push(child);
}
}
} while (!queue.empty());
}
} // namespace mold
-50
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@@ -1,50 +0,0 @@
// This is the same as std::atomic except that the default memory
// order is relaxed instead of sequential consistency.
#pragma once
#include <atomic>
namespace mold {
template <typename T>
struct Atomic : std::atomic<T> {
static constexpr std::memory_order relaxed = std::memory_order_relaxed;
using std::atomic<T>::atomic;
Atomic(const Atomic<T> &other) : std::atomic<T>(other.load()) {}
Atomic<T> &operator=(const Atomic<T> &other) {
store(other.load());
return *this;
}
void operator=(T val) { store(val); }
operator T() const { return load(); }
void store(T val, std::memory_order order = relaxed) {
std::atomic<T>::store(val, order);
}
T load(std::memory_order order = relaxed) const {
return std::atomic<T>::load(order);
}
T exchange(T val) { return std::atomic<T>::exchange(val, relaxed); }
T operator|=(T val) { return std::atomic<T>::fetch_or(val, relaxed); }
T operator++() { return std::atomic<T>::fetch_add(1, relaxed) + 1; }
T operator--() { return std::atomic<T>::fetch_sub(1, relaxed) - 1; }
T operator++(int) { return std::atomic<T>::fetch_add(1, relaxed); }
T operator--(int) { return std::atomic<T>::fetch_sub(1, relaxed); }
bool test_and_set() {
// A relaxed load + branch (assuming miss) takes only around 20 cycles,
// while an atomic RMW can easily take hundreds on x86. We note that it's
// common that another thread beat us in marking, so doing an optimistic
// early test tends to improve performance in the ~20% ballpark.
return load() || exchange(true);
}
};
} // namespace mold
-78
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@@ -1,78 +0,0 @@
#pragma once
#include "integers.h"
#include <cassert>
#include <vector>
namespace mold {
class BitvectorProxy {
public:
BitvectorProxy(u64 &word, size_t pos)
: word(word), mask(1ULL << pos) {}
BitvectorProxy &operator=(bool val) {
if (val)
word |= mask;
else
word &= ~mask;
return *this;
}
BitvectorProxy &operator=(const BitvectorProxy &other) {
return *this = (bool)other;
}
operator bool() const {
return word & mask;
}
private:
u64 &word;
u64 mask;
};
class Bitvector {
public:
Bitvector() = default;
Bitvector(i64 n) : size(n), words((n + 63) / 64) {}
void resize(i64 n) {
words.clear();
words.resize((n + 63) / 64);
size = n;
}
Bitvector &operator|=(const Bitvector &x) {
assert(size == x.size);
for (i64 i = 0; i < words.size(); i++)
words[i] |= x.words[i];
return *this;
}
Bitvector &operator&=(const Bitvector &x) {
assert(size == x.size);
for (i64 i = 0; i < words.size(); i++)
words[i] &= x.words[i];
return *this;
}
Bitvector &operator<<=(size_t n) {
assert(n == 1);
for (i64 i = words.size() - 1; i > 0; i--)
words[i] = (words[i] << 1) | (words[i - 1] >> 63);
words[0] <<= 1;
return *this;
}
BitvectorProxy operator[](size_t pos) {
assert(pos < size);
return {words[pos / 64], pos % 64};
}
i64 size = 0;
std::vector<u64> words;
};
} // namespace mold
-174
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@@ -1,174 +0,0 @@
// This file implements a multi-threaded zlib and zstd compression
// routine.
//
// zlib-compressed data can be merged just by concatenation as long as
// each piece of data is flushed with Z_SYNC_FLUSH. In this file, we
// split input data into multiple shards, compress them individually
// and concatenate them. We then append a header, a trailer and a
// checksum so that the concatenated data is valid zlib-format data.
//
// zstd-compressed data can be merged in the same way.
//
// Using threads to compress data has a downside. Since the dictionary
// is reset on boundaries of shards, compression ratio is sacrificed
// a little bit. However, if a shard size is large enough, that loss
// is negligible in practice.
#include "lib.h"
#include <tbb/parallel_for_each.h>
#include <zlib.h>
#include <zstd.h>
#define CHECK(fn) \
do { \
[[maybe_unused]] int r = (fn); \
assert(r == Z_OK); \
} while (0)
namespace mold {
static constexpr i64 SHARD_SIZE = 1024 * 1024;
Compressor::~Compressor() {
for (std::span<u8> shard : shards)
delete[] shard.data();
}
static std::vector<std::span<u8>> split(std::span<u8> input) {
std::vector<std::span<u8>> vec;
while (!input.empty()) {
i64 sz = std::min<i64>(SHARD_SIZE, input.size());
vec.push_back(input.subspan(0, sz));
input = input.subspan(sz);
}
return vec;
}
static std::span<u8> zlib_compress(std::span<u8> input, int level) {
// Initialize zlib stream. Since debug info is generally compressed
// pretty well with lower compression levels, the default level is 1.
z_stream strm = {};
CHECK(deflateInit2(&strm, level, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY));
// Set an input buffer
strm.avail_in = input.size();
strm.next_in = input.data();
// Set an output buffer. deflateBound() returns an upper bound
// on the compression size. +16 for Z_SYNC_FLUSH.
i64 bufsize = deflateBound(&strm, strm.avail_in) + 16;
u8 *buf = new u8[bufsize];
// Compress data. It writes all compressed bytes except the last
// partial byte, so up to 7 bits can be held to be written to the
// buffer.
strm.avail_out = bufsize;
strm.next_out = buf;
CHECK(deflate(&strm, Z_BLOCK));
// This is a workaround for libbacktrace before 2022-04-06.
//
// Zlib is a bit stream, and what Z_SYNC_FLUSH does is to write a
// three bit value indicating the start of an uncompressed data
// block followed by four byte data 00 00 ff ff which indicates that
// the length of the block is zero. libbacktrace uses its own zlib
// inflate routine, and it had a bug that if that particular three
// bit value happens to end at a byte boundary, it accidentally
// skipped the next byte.
//
// In order to avoid triggering that bug, we should avoid calling
// deflate() with Z_SYNC_FLUSH if the current bit position is 5.
// If it's 5, we insert an empty block consisting of 10 bits so
// that the bit position is 7 in the next byte.
//
// https://github.com/ianlancetaylor/libbacktrace/pull/87
int nbits = 0;
deflatePending(&strm, Z_NULL, &nbits);
if (nbits == 5)
CHECK(deflatePrime(&strm, 10, 2));
CHECK(deflate(&strm, Z_SYNC_FLUSH));
deflateEnd(&strm);
return {buf, (size_t)(bufsize - strm.avail_out)};
}
ZlibCompressor::ZlibCompressor(u8 *buf, i64 size, i64 level) {
std::vector<std::span<u8>> inputs = split(std::span(buf, size));
std::vector<u32> adlers(inputs.size());
shards.resize(inputs.size());
// Compress each shard
tbb::parallel_for((i64)0, (i64)inputs.size(), [&](i64 i) {
std::span<u8> in = inputs[i];
adlers[i] = adler32(1, in.data(), in.size());
shards[i] = zlib_compress(in, level);
});
// Combine checksums
checksum = adlers[0];
for (i64 i = 1; i < inputs.size(); i++)
checksum = adler32_combine(checksum, adlers[i], inputs[i].size());
// Comput the total size
compressed_size = 8; // the header and the trailer
for (std::span<u8> &shard : shards)
compressed_size += shard.size();
}
void ZlibCompressor::write_to(u8 *buf) {
// Write a zlib-format header
buf[0] = 0x78;
buf[1] = 0x9c;
// Copy compressed data
std::vector<i64> offsets(shards.size());
offsets[0] = 2; // +2 for the header
for (i64 i = 1; i < shards.size(); i++)
offsets[i] = offsets[i - 1] + shards[i - 1].size();
tbb::parallel_for((i64)0, (i64)shards.size(), [&](i64 i) {
memcpy(buf + offsets[i], shards[i].data(), shards[i].size());
});
// Write a trailer
u8 *end = buf + compressed_size;
end[-6] = 3;
end[-5] = 0;
*(ub32 *)(end - 4) = checksum;
}
static std::span<u8> zstd_compress(std::span<u8> input, int level) {
i64 bufsize = ZSTD_COMPRESSBOUND(input.size());
u8 *buf = new u8[bufsize];
size_t sz = ZSTD_compress(buf, bufsize, input.data(), input.size(), level);
assert(!ZSTD_isError(sz));
return {buf, sz};
}
ZstdCompressor::ZstdCompressor(u8 *buf, i64 size, i64 level) {
std::vector<std::span<u8>> inputs = split(std::span(buf, size));
shards.resize(inputs.size());
// Compress each shard
tbb::parallel_for((i64)0, (i64)inputs.size(), [&](i64 i) {
shards[i] = zstd_compress(inputs[i], level);
});
compressed_size = 0;
for (std::span<u8> &shard : shards)
compressed_size += shard.size();
}
void ZstdCompressor::write_to(u8 *buf) {
// Copy compressed data
std::vector<i64> offsets(shards.size());
for (i64 i = 1; i < shards.size(); i++)
offsets[i] = offsets[i - 1] + shards[i - 1].size();
tbb::parallel_for((i64)0, (i64)shards.size(), [&](i64 i) {
memcpy(buf + offsets[i], shards[i].data(), shards[i].size());
});
}
} // namespace mold
-29
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@@ -1,29 +0,0 @@
#define MOLD_VERSION "@mold_VERSION@"
#define MOLD_LIBDIR "@CMAKE_INSTALL_FULL_LIBDIR@"
#define MOLD_FIRST_TARGET @MOLD_FIRST_TARGET@
#cmakedefine01 HAVE_MADVISE
#cmakedefine01 HAVE_UNAME
#cmakedefine01 MOLD_USE_MIMALLOC
#cmakedefine01 MOLD_USE_SYSTEM_MIMALLOC
#cmakedefine01 HAVE_TARGET_X86_64
#cmakedefine01 HAVE_TARGET_I386
#cmakedefine01 HAVE_TARGET_ARM64LE
#cmakedefine01 HAVE_TARGET_ARM64BE
#cmakedefine01 HAVE_TARGET_ARM32LE
#cmakedefine01 HAVE_TARGET_ARM32BE
#cmakedefine01 HAVE_TARGET_RV32LE
#cmakedefine01 HAVE_TARGET_RV32BE
#cmakedefine01 HAVE_TARGET_RV64LE
#cmakedefine01 HAVE_TARGET_RV64BE
#cmakedefine01 HAVE_TARGET_PPC32
#cmakedefine01 HAVE_TARGET_PPC64V1
#cmakedefine01 HAVE_TARGET_PPC64V2
#cmakedefine01 HAVE_TARGET_S390X
#cmakedefine01 HAVE_TARGET_SPARC64
#cmakedefine01 HAVE_TARGET_M68K
#cmakedefine01 HAVE_TARGET_SH4LE
#cmakedefine01 HAVE_TARGET_SH4BE
#cmakedefine01 HAVE_TARGET_LOONGARCH64
#cmakedefine01 HAVE_TARGET_LOONGARCH32
-60
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#include "lib.h"
#include <tbb/parallel_for_each.h>
#include <zlib.h>
namespace mold {
// This function "forges" a CRC. That is, given the current and a desired
// CRC32 value, crc32_solve() returns a binary blob to add to the end of
// the original data to yield the desired CRC. Trailing garbage is ignored
// by many bianry file formats, so you can create a file with a desired
// CRC using crc32_solve(). We need it for --separate-debug-file.
std::vector<u8> crc32_solve(u32 current, u32 desired) {
constexpr u32 poly = 0xedb88320;
u32 x = ~desired;
// Each iteration computes x = (x * x^-1) mod poly.
for (i64 i = 0; i < 32; i++) {
x = std::rotl(x, 1);
x ^= (x & 1) * (poly << 1);
}
x ^= ~current;
std::vector<u8> out(4);
out[0] = x;
out[1] = x >> 8;
out[2] = x >> 16;
out[3] = x >> 24;
return out;
}
// Compute a CRC for given data in parallel
u32 compute_crc32(u32 crc, u8 *buf, i64 len) {
struct Shard {
u8 *buf;
i64 len;
u32 crc;
};
constexpr i64 shard_size = 1024 * 1024; // 1 MiB
std::vector<Shard> shards;
while (len > 0) {
i64 sz = std::min(len, shard_size);
shards.push_back({buf, sz, 0});
buf += sz;
len -= sz;
}
tbb::parallel_for_each(shards, [](Shard &shard) {
shard.crc = crc32(0, shard.buf, shard.len);
});
for (Shard &shard : shards)
crc = crc32_combine(crc, shard.crc, shard.len);
return crc;
}
} // namespace mold
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#include "lib.h"
#include <cstdlib>
#ifndef _WIN32
#include <cxxabi.h>
#endif
#include "../third-party/rust-demangle/rust-demangle.h"
namespace mold {
std::optional<std::string_view> demangle_cpp(std::string_view name) {
static thread_local char *buf;
static thread_local size_t buflen;
// TODO(cwasser): Actually demangle Symbols on Windows using e.g.
// `UnDecorateSymbolName` from Dbghelp, maybe even Itanium symbols?
#ifndef _WIN32
if (name.starts_with("_Z")) {
int status;
char *p = abi::__cxa_demangle(std::string(name).c_str(), buf, &buflen, &status);
if (status == 0) {
buf = p;
return p;
}
}
#endif
return {};
}
std::optional<std::string_view> demangle_rust(std::string_view name) {
static thread_local char *buf;
free(buf);
buf = rust_demangle(std::string(name).c_str(), 0);
if (buf)
return buf;
return {};
}
} // namespace mold
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#include "lib.h"
#include <filesystem>
#include <sys/stat.h>
#ifdef __APPLE__
# include <mach-o/dyld.h>
#endif
#ifdef __FreeBSD__
# include <sys/sysctl.h>
#endif
namespace mold {
// Returns the path of the mold executable itself
std::string get_self_path() {
#if __APPLE__ || _WIN32
fprintf(stderr, "mold: get_self_path is not supported");
exit(1);
#elif __FreeBSD__
// /proc may not be mounted on FreeBSD. The proper way to get the
// current executable's path is to use sysctl(2).
int mib[4];
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_PATHNAME;
mib[3] = -1;
size_t size;
sysctl(mib, 4, NULL, &size, NULL, 0);
std::string path;
path.resize(size);
sysctl(mib, 4, path.data(), &size, NULL, 0);
return path;
#else
return std::filesystem::read_symlink("/proc/self/exe").string();
#endif
}
} // namespace mold
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#!/bin/bash
#
# This test script takes a Gentoo package name and tries to build it
# using mold in a Podman environment. We chose Gentoo Linux as a test
# target, because its source-based package allows us to build programs
# locally and run their test suites without any hassle.
#
# You can get a complete list of Gentoo packages availalbe for testing
# with the following command:
#
# podman run --rm mold-gentoo emerge --color n -s '' | \
# perl -ne 'next unless m!^\*\s+(\S+/\S+)!; print "$1\n"'
package="$1"
if [ "$package" = "" ]; then
echo "Usage: $0 gentoo-package-name"
exit 1
fi
set -x
# Create a Podman image
if ! podman image ls mold-gentoo | grep -q mold-gentoo; then
set -e
cat <<EOF | podman build -t mold-gentoo -
FROM docker.io/gentoo/stage3
RUN emerge-webrsync
RUN echo 'USE="X ssl elogind -systemd corefonts truetype jpeg jpeg2k tiff zstd static-libs binary -perl"' >> /etc/portage/make.conf && \
echo 'ACCEPT_KEYWORDS="~amd64"' >> /etc/portage/make.conf && \
echo 'ACCEPT_LICENSE="* -@EULA"' >> /etc/portage/make.conf && \
echo 'FEATURES="\${FEATURE} noclean nostrip ccache -ipc-sandbox -network-sandbox -pid-sandbox -sandbox"' >> /etc/portage/make.conf && \
echo 'CCACHE_DIR="/ccache"' >> /etc/portage/make.conf && \
FEATURES='getbinpkg binpkg-request-signature' emerge gdb lld llvm-core/clang vim emacs strace ccache xeyes dev-build/cmake dev-vcs/git && \
rm -rf /var/tmp/portage
EOF
set +e
fi
git_hash=$(./dist/mold --version | perl -ne '/\((\w+)/; print $1;')
if [ "$package" = dev-libs/concurrencykit ]; then
echo "Skipping known broken package: $package"
exit 0
fi
# Build a given package in Podman
cmd1='(cd /usr/bin; ln -sf /mold/dist/mold $(realpath ld))'
cmd2="MAKEOPTS=-'j$(nproc) --load-average=100' emerge --onlydeps $package"
cmd3="MAKEOPTS='-j$(nproc) --load-average=100' FEATURES=test emerge $package"
filename=`echo "$package" | sed 's!/!_!g'`
podman="podman run --rm --pids-limit=-1 --cap-add=SYS_PTRACE -v `pwd`:/mold:ro -v /var/cache/ccache-gentoo:/ccache mold-gentoo timeout -v -k 15s 3h"
dir=gentoo/$git_hash
mkdir -p "$dir"/success "$dir"/failure
$podman chrt --idle 0 nice -n 19 bash -c "$cmd1 && $cmd2 && $cmd3" >& "$dir"/"$filename".mold
if [ $? = 0 ]; then
mv "$dir"/"$filename".mold "$dir"/success
else
mv "$dir"/"$filename".mold "$dir"/failure
fi
$podman chrt --idle 0 nice -n 19 bash -c "$cmd2 && $cmd3" >& "$dir"/"$filename".ld
if [ $? = 0 ]; then
mv "$dir"/"$filename".ld "$dir"/success
else
mv "$dir"/"$filename".ld "$dir"/failure
fi
-256
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// This file implements a glob matcher that can run multiple glob patterns
// against an input string. mold uses the glob matcher for symbol name
// patterns in a version script or a dynamic list file. Since we may need to
// match hundreds of glob patterns against millions of symbol names, the
// speed of the matcher is very important.
//
// The pattern match implemented in this file is NFA-based, although the
// cost of the function is O(n*m), where n is the number of NFA states and m
// is the length of the input string. We do not use recursion or
// backtracking, unlike a generic NFA-based regular expression matcher. This
// is doable because glob patterns are very limited subsets of regexes.
//
// Here is the explanation of the algorithm. Observe that the only "tricky"
// meta-character in a glob pattern is "*", which matches zero or more
// characters. Other characters and meta-characters always match a single
// input character. So the key of the algorithm is to handle "*" efficiently.
//
// We can represent a glob pattern "a*b*" with three NFA states: q_start, q1
// and q_accept, with the following transition functions:
//
// δ(q_start, "a") = q1
// δ(q1, <any character>) = q1
// δ(q1, "b") = q_accept
// δ(q_accept, <any character>) = q_accept
//
// We can construct such an NFA in a straightforward manner. We maintain NFA
// states as a list, with the initial contents being the start state. Each
// character except for "*" creates a new NFA state, adds a transition from
// the last state in the list to the new one, and appends the new state at
// the end of the list. "*" sets the "is_star" flag on the last NFA state.
// The flag indicates that the state machine can remain in the state for any
// input character.
//
// An NFA constructed this way doesn't have any complicated loops,
// ε-transitions, or anything like that. Each state has only one incoming
// edge. The only loops in the state transition are the self-loops on states
// followed by a "*". Aside from that, the state machine progresses linearly
// from the start state to the accept state.
//
// Each state of an NFA can be represented by a single bit. If a bit is 1,
// the non-deterministic state machine is in that state. Otherwise, it's
// not. Observe that a state with the "is_star" flag will continued to be 1
// once it becomes 1, since the state machine can loop over the state on any
// input character.
//
// With that observation, we can represent an NFA with a bit vector of N
// bits, where N is the number of NFA states. For each input character, bit
// M becomes 1 if
//
// - bit M-1 is 1 and there's a transition from state_{M-1} to state_M
// with the given character, or
// - bit M is 1 and state_M's "is_star" flag is 1.
//
// Initially, the 0th bit is 1 for the start state. At each step, the bits
// propagate from least significant to most significant positions, at most
// one bit at a time. If the most significant bit is 1 after the entire
// input has been processed, the string matches.
//
// This propagation can be implemented with bitwise OR, bitwise AND, and a
// one-bit bit shift on the bit vector. All these operations are very cheap.
//
// We can combine multiple glob matchers into a single matcher by simply
// concatenating the bit vectors of their state machines.
#include "lib.h"
#include <cstring>
namespace mold {
static std::vector<MultiGlob::State> parse_glob(std::string_view pat) {
std::vector<MultiGlob::State> vec(1);
while (!pat.empty()) {
u8 c = pat[0];
pat = pat.substr(1);
std::bitset<256> chars;
switch (c) {
case '*':
vec.back().is_star = true;
continue;
case '?':
chars.set();
break;
case '\\':
if (pat.empty())
return {};
chars[pat[0]] = true;
pat = pat.substr(1);
break;
case '[': {
// Here are a few bracket pattern examples:
//
// [abc]: a, b or c
// [$\]!]: $, ] or !
// [a-czg-i]: a, b, c, z, g, h, or i
// [!a-z]: Any character except lowercase letters
//
// Both `!` and `^` are accepted as negation markers. `!` is the
// POSIX/shell convention used by other linkers. `^` was mold's
// original syntax and is kept for backward compatibility.
bool negate = false;
bool closed = false;
if (!pat.empty() && (pat[0] == '!' || pat[0] == '^')) {
negate = true;
pat = pat.substr(1);
}
while (!pat.empty()) {
if (pat[0] == ']') {
pat = pat.substr(1);
closed = true;
break;
}
if (pat[0] == '\\') {
pat = pat.substr(1);
if (pat.empty())
return {};
}
if (pat.size() >= 3 && pat[1] == '-') {
u8 start = pat[0];
u8 end = pat[2];
pat = pat.substr(3);
if (end == '\\') {
if (pat.empty())
return {};
end = pat[0];
pat = pat.substr(1);
}
if (end < start)
return {};
for (i64 i = start; i <= end; i++)
chars[i] = true;
} else {
chars[pat[0]] = true;
pat = pat.substr(1);
}
}
if (!closed)
return {};
if (negate)
chars.flip();
break;
}
default:
chars[c] = true;
break;
}
vec.push_back({chars, false});
}
return vec;
}
// Instead of returning just a match/no match boolean value, our glob
// matcher returns an integer value associated with each given pattern.
// If multiple patterns match at the same time, the largest associated
// value will be returned by find().
bool MultiGlob::add(std::string_view pat, i64 val) {
std::vector<State> vec = parse_glob(pat);
if (vec.empty())
return false;
patterns.push_back({std::move(vec), val});
return true;
}
void MultiGlob::compile() {
if (patterns.empty())
return;
ranges::stable_sort(patterns, ranges::greater(), &GlobPattern::value);
std::vector<State> states;
for (GlobPattern &p : patterns)
append(states, p.states);
i64 sz = states.size();
start_states.resize(sz);
for (i64 pos = 0; GlobPattern &p : patterns) {
start_states[pos] = true;
pos += p.states.size();
}
star_mask.resize(sz);
for (i64 i = 0; i < sz; i++)
if (states[i].is_star)
star_mask[i] = true;
for (i64 i = 0; i < 256; i++) {
char_mask[i].resize(sz);
for (i64 j = 0; j < sz; j++)
if (states[j].incoming_edge[i])
char_mask[i][j] = true;
}
}
i64 MultiGlob::find(std::string_view str) {
if (patterns.empty())
return -1;
Bitvector bits = start_states;
Bitvector tmp;
for (u8 c : str) {
// This is equivalent to
//
// bits = (bits & star_mask) | ((bits << 1) & char_mask[c])
//
// but we update the existing objects in place to avoid allocating
// temporary objects.
tmp = bits;
tmp &= star_mask;
bits <<= 1;
bits &= char_mask[c];
bits |= tmp;
}
for (i64 pos = 0; GlobPattern &p : patterns) {
pos += p.states.size();
if (bits[pos - 1])
return p.value;
}
return -1;
}
bool Glob::add(std::string_view pat, i64 val) {
assert(val >= 0);
assert(!is_compiled);
// If the pattern requires only a single substring search, the
// Aho-Corasick algorithm is even faster than our glob matcher.
if (aho_corasick.can_handle(pat))
return aho_corasick.add(pat, val);
return multi_glob.add(pat, val);
}
i64 Glob::find(std::string_view str) {
std::call_once(once, [&] {
multi_glob.compile();
aho_corasick.compile();
is_compiled = true;
});
return std::max(multi_glob.find(str), aho_corasick.find(str));
}
} // namespace mold
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// This file implements HyperLogLog algorithm, which estimates
// the number of unique items in a given multiset.
//
// For more info, read
// https://engineering.fb.com/2018/12/13/data-infrastructure/hyperloglog
#include "lib.h"
#include <cmath>
namespace mold {
i64 HyperLogLog::get_cardinality() const {
double z = 0;
for (i64 val : buckets)
z += std::ldexp(1.0, -val);
return ALPHA * NBUCKETS * NBUCKETS / z;
}
} // namespace mold
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// This file defines integral types for file input/output. We need to use
// these types instead of the plain integers (such as uint32_t or int32_t)
// when reading from/writing to an mmap'ed file area for the following
// reasons:
//
// 1. mold is always a cross linker and should not depend on what host it
// is running on. For example, users should be able to run mold on a
// little-endian x86 machine to create a big-endian s390x binary.
//
// 2. Even though data members in all ELF data strucutres are naturally
// aligned, they are not guaranteed to be aligned on memory because of
// archive files. Archive files (.a files) align each file only to a
// 2 byte boundary, so anything larger than 2 bytes may be misaligned
// in an mmap'ed memory. Misaligned access is an undefined behavior in
// C/C++, so we shouldn't cast an arbitrary pointer to a uint32_t, for
// example, to read a 32 bit value.
//
// The data types defined in this file are independent of the host byte
// order and are designed to avoid unaligned access.
//
// Note that in C/C++, memcpy is a portable and efficient way to access
// unaligned data, as it is typically treated as an intrinsic. Compilers
// can easily optimize memcpy calls in this file into a single load or
// store instruction.
#pragma once
#include <bit>
#include <cstdint>
#include <cstring>
#include <type_traits>
#if !defined(__LITTLE_ENDIAN__) && !defined(__BIG_ENDIAN__)
# if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
# define __LITTLE_ENDIAN__ 1
# elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
# define __BIG_ENDIAN__ 1
# else
# error "unknown host byte order"
# endif
#endif
namespace mold {
template <typename T, bool is_le, int size = sizeof(T)>
class Integer {
public:
constexpr Integer() = default;
constexpr Integer(T v) {
if (std::is_constant_evaluated() || size == 3) {
for (int i = 0; i < size; i++)
buf[is_le ? i : (size - i - 1)] = v >> (i * 8);
} else {
if (!is_native)
v = bswap(v);
memcpy(buf, &v, size);
}
}
operator T() const {
if (size == 3) {
if (is_le)
return buf[2] << 16 | buf[1] << 8 | buf[0];
return buf[0] << 16 | buf[1] << 8 | buf[2];
}
T v;
memcpy(&v, buf, size);
return is_native ? v : bswap(v);
}
Integer &operator=(T v) { new (this) Integer(v); return *this; }
Integer &operator++() { return *this = *this + 1; }
Integer operator++(int) { auto x = *this; ++*this; return x; }
Integer &operator--() { return *this = *this - 1; }
Integer operator--(int) { auto x = *this; --*this; return x; }
Integer &operator+=(T v) { return *this = *this + v; }
Integer &operator-=(T v) { return *this = *this - v; }
Integer &operator&=(T v) { return *this = *this & v; }
Integer &operator|=(T v) { return *this = *this | v; }
private:
static constexpr bool is_native =
(std::endian::native == (is_le ? std::endian::little : std::endian::big));
static T bswap(T v) {
switch (size) {
case 2: return __builtin_bswap16(v);
case 4: return __builtin_bswap32(v);
case 8: return __builtin_bswap64(v);
default: __builtin_unreachable();
}
}
uint8_t buf[size];
};
using i8 = int8_t;
using i16 = int16_t;
using i32 = int32_t;
using i64 = int64_t;
using u8 = uint8_t;
using u16 = uint16_t;
using u32 = uint32_t;
using u64 = uint64_t;
using il16 = Integer<i16, true>;
using il32 = Integer<i32, true>;
using il64 = Integer<i64, true>;
using ul16 = Integer<u16, true>;
using ul24 = Integer<u32, true, 3>;
using ul32 = Integer<u32, true>;
using ul64 = Integer<u64, true>;
using ib16 = Integer<i16, false>;
using ib32 = Integer<i32, false>;
using ib64 = Integer<i64, false>;
using ub16 = Integer<u16, false>;
using ub24 = Integer<u32, false, 3>;
using ub32 = Integer<u32, false>;
using ub64 = Integer<u64, false>;
} // namespace mold
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@@ -1,709 +0,0 @@
#pragma once
#include "atomics.h"
#include "integers.h"
#include "bitvector.h"
#include <array>
#include <atomic>
#include <bit>
#include <bitset>
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fcntl.h>
#include <filesystem>
#include <iostream>
#include <mutex>
#include <optional>
#include <span>
#include <sstream>
#include <string>
#include <string_view>
#include <sys/stat.h>
#include <sys/types.h>
#include <tbb/concurrent_vector.h>
#include <tbb/enumerable_thread_specific.h>
#include <tbb/parallel_for.h>
#include <vector>
#ifdef _WIN32
# include <io.h>
#else
# include <sys/mman.h>
# include <unistd.h>
#endif
#define XXH_INLINE_ALL 1
#include "../third-party/xxhash/xxhash.h"
#ifdef NDEBUG
# define unreachable() __builtin_unreachable()
#else
# define unreachable() assert(0 && "unreachable")
#endif
inline uint64_t hash_string(std::string_view str) {
return XXH3_64bits(str.data(), str.size());
}
class HashCmp {
public:
static size_t hash(const std::string_view &k) {
return hash_string(k);
}
static bool equal(const std::string_view &k1, const std::string_view &k2) {
return k1 == k2;
}
};
namespace mold {
namespace ranges = std::ranges;
using namespace std::literals::string_literals;
using namespace std::literals::string_view_literals;
inline u64 combine_hash(u64 a, u64 b) {
return a ^ (b + 0x9e3779b9 + (a << 6) + (a >> 2));
}
//
// perf.cc
//
// Counter is used to collect statistics numbers.
class Counter {
public:
Counter(std::string_view name, i64 value = 0) : name(name), values(value) {
static std::mutex mu;
std::scoped_lock lock(mu);
instances.push_back(this);
}
Counter &operator++(int) {
if (enabled) [[unlikely]]
values.local()++;
return *this;
}
Counter &operator+=(int delta) {
if (enabled) [[unlikely]]
values.local() += delta;
return *this;
}
static void print();
static inline bool enabled = false;
private:
i64 get_value();
std::string_view name;
tbb::enumerable_thread_specific<i64> values;
static inline std::vector<Counter *> instances;
};
// Timer and TimeRecord records elapsed time (wall clock time)
// used by each pass of the linker.
struct TimerRecord {
TimerRecord(std::string name, TimerRecord *parent = nullptr);
void stop();
std::string name;
TimerRecord *parent;
tbb::concurrent_vector<TimerRecord *> children;
i64 start;
i64 end;
i64 user;
i64 sys;
bool stopped = false;
};
void
print_timer_records(tbb::concurrent_vector<std::unique_ptr<TimerRecord>> &);
template <typename Context>
class Timer {
public:
Timer(Context &ctx, std::string name, Timer *parent = nullptr) {
record = new TimerRecord(name, parent ? parent->record : nullptr);
ctx.timer_records.emplace_back(record);
}
Timer(const Timer &) = delete;
~Timer() {
record->stop();
}
void stop() {
record->stop();
}
private:
TimerRecord *record;
};
//
// Utility functions
//
// Some C++ libraries haven't implemented std::has_single_bit yet.
inline bool has_single_bit(u64 val) {
return std::popcount(val) == 1;
}
// Some C++ libraries haven't implemented std::bit_ceil yet.
inline u64 bit_ceil(u64 val) {
if (has_single_bit(val))
return val;
return 1LL << (64 - std::countl_zero(val));
}
inline u64 align_to(u64 val, u64 align) {
if (align == 0)
return val;
assert(has_single_bit(align));
return (val + align - 1) & ~(align - 1);
}
inline u64 align_down(u64 val, u64 align) {
assert(has_single_bit(align));
return val & ~(align - 1);
}
inline u64 bit(u64 val, i64 pos) {
return (val >> pos) & 1;
};
// Returns [hi:lo] bits of val.
inline u64 bits(u64 val, u64 hi, u64 lo) {
return (val >> lo) & ((1LL << (hi - lo + 1)) - 1);
}
// Cast val to a signed N bit integer.
// For example, sign_extend(x, 32) == (i32)x for any integer x.
inline i64 sign_extend(u64 val, i64 n) {
return (i64)(val << (64 - n)) >> (64 - n);
}
inline bool is_int(u64 val, i64 n) {
return sign_extend(val, n) == val;
}
template <typename T, typename Compare = std::less<T>>
void update_minimum(std::atomic<T> &atomic, u64 new_val, Compare cmp = {}) {
T old_val = atomic.load(std::memory_order_relaxed);
while (cmp(new_val, old_val) &&
!atomic.compare_exchange_weak(old_val, new_val,
std::memory_order_relaxed));
}
template <typename T, typename Compare = std::less<T>>
void update_maximum(std::atomic<T> &atomic, u64 new_val, Compare cmp = {}) {
T old_val = atomic.load(std::memory_order_relaxed);
while (cmp(old_val, new_val) &&
!atomic.compare_exchange_weak(old_val, new_val,
std::memory_order_relaxed));
}
template <typename T>
inline void append(std::vector<T> &x, const auto &y) {
x.insert(x.end(), y.begin(), y.end());
}
template <typename T>
inline std::vector<T> flatten(std::vector<std::vector<T>> &vec) {
i64 size = 0;
for (std::vector<T> &v : vec)
size += v.size();
std::vector<T> ret;
ret.reserve(size);
for (std::vector<T> &v : vec)
append(ret, v);
return ret;
}
template <typename T>
inline void remove_duplicates(std::vector<T> &vec) {
vec.erase(std::unique(vec.begin(), vec.end()), vec.end());
}
inline i64 write_string(void *buf, std::string_view str) {
memcpy(buf, str.data(), str.size());
*((u8 *)buf + str.size()) = '\0';
return str.size() + 1;
}
template <typename T>
inline void write_vector(void *buf, const std::vector<T> &vec) {
if (!vec.empty())
memcpy(buf, vec.data(), vec.size() * sizeof(T));
}
inline void encode_uleb(std::vector<u8> &vec, u64 val) {
do {
u8 byte = val & 0x7f;
val >>= 7;
vec.push_back(val ? (byte | 0x80) : byte);
} while (val);
}
inline void encode_sleb(std::vector<u8> &vec, i64 val) {
for (;;) {
u8 byte = val & 0x7f;
val >>= 7;
bool neg = (byte & 0x40);
if ((val == 0 && !neg) || (val == -1 && neg)) {
vec.push_back(byte);
break;
}
vec.push_back(byte | 0x80);
}
}
inline i64 write_uleb(u8 *buf, u64 val) {
i64 i = 0;
do {
u8 byte = val & 0x7f;
val >>= 7;
buf[i++] = val ? (byte | 0x80) : byte;
} while (val);
return i;
}
inline u64 read_uleb(u8 **buf) {
u64 val = 0;
u8 shift = 0;
u8 byte;
do {
byte = *(*buf)++;
val |= (byte & 0x7f) << shift;
shift += 7;
} while (byte & 0x80);
return val;
}
inline u64 read_uleb(u8 *buf) {
u8 *tmp = buf;
return read_uleb(&tmp);
}
inline i64 read_sleb(u8 **buf) {
u64 val = 0;
u8 shift = 0;
u8 byte;
do {
byte = *(*buf)++;
val |= (byte & 0x7f) << shift;
shift += 7;
} while (byte & 0x80);
return sign_extend(val, shift);
}
inline i64 read_sleb(u8 *buf) {
u8 *tmp = buf;
return read_sleb(&tmp);
}
inline u64 read_uleb(std::string_view *str) {
u8 *start = (u8 *)str->data();
u8 *ptr = start;
u64 val = read_uleb(&ptr);
*str = str->substr(ptr - start);
return val;
}
inline u64 read_uleb(std::string_view str) {
std::string_view tmp = str;
return read_uleb(&tmp);
}
inline i64 uleb_size(u64 val) {
for (int i = 1; i < 9; i++)
if (val < (1LL << (7 * i)))
return i;
return 9;
}
inline void overwrite_uleb(u8 *loc, u64 val) {
while (*loc & 0b1000'0000) {
*loc++ = 0b1000'0000 | (val & 0b0111'1111);
val >>= 7;
}
*loc = val & 0b0111'1111;
}
static inline void pause() {
#if defined(__x86_64__)
asm volatile("pause");
#elif defined(__aarch64__)
asm volatile("yield");
#elif defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_8A__)
asm volatile("yield");
#endif
}
//
// Concurrent Map
//
// This is an implementation of a fast concurrent hash map. Unlike
// ordinary hash tables, this impl just aborts if it becomes full.
// So you need to give a correct estimation of the final size before
// using it. We use this hash map to uniquify pieces of data in
// mergeable sections.
//
// We've implemented this ourselves because the performance of
// conrurent hash map is critical for our linker.
template <typename T>
class ConcurrentMap {
public:
ConcurrentMap() = default;
ConcurrentMap(i64 nbuckets) {
resize(nbuckets);
}
~ConcurrentMap() {
if (entries) {
#ifdef _WIN32
_aligned_free(entries);
#else
munmap(entries, sizeof(Entry) * nbuckets);
#endif
}
}
// In order to avoid unnecessary cache-line false sharing, we want
// to make this object to be aligned to a reasonably large
// power-of-two address.
struct alignas(32) Entry {
Atomic<const char *> key;
u32 keylen;
T value;
};
void resize(i64 nbuckets) {
assert(!entries);
this->nbuckets = std::max<i64>(MIN_NBUCKETS, bit_ceil(nbuckets));
i64 bufsize = sizeof(Entry) * this->nbuckets;
// Allocate a zero-initialized buffer. mmap() is faster than
// malloc()+memset(), and MAP_POPULATE pre-faults pages here to
// avoid CoW faults and TLB shootdowns under concurrent inserts.
#ifdef _WIN32
entries = (Entry *)_aligned_malloc(bufsize, alignof(Entry));
memset((void *)entries, 0, bufsize);
#elif MAP_POPULATE
entries = (Entry *)mmap(nullptr, bufsize, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE | MAP_POPULATE, -1, 0);
#else
entries = (Entry *)mmap(nullptr, bufsize, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
#endif
}
std::pair<T *, bool> insert(std::string_view key, u64 hash, const T &val) {
assert(has_single_bit(nbuckets));
u64 begin = hash & (nbuckets - 1);
u64 mask = nbuckets / NUM_SHARDS - 1;
for (i64 i = 0; i < MAX_RETRY; i++) {
u64 idx = (begin & ~mask) | ((begin + i) & mask);
Entry &ent = entries[idx];
// It seems avoiding compare-and-swap is faster overall at least
// on my Zen4 machine, so do it.
if (const char *ptr = ent.key.load(std::memory_order_acquire);
ptr != nullptr && ptr != (char *)-1) {
if (key == std::string_view(ptr, ent.keylen))
return {&ent.value, false};
continue;
}
// Otherwise, use CAS to atomically claim the ownership of the slot.
const char *ptr = nullptr;
bool claimed = ent.key.compare_exchange_strong(ptr, (char *)-1,
std::memory_order_acquire);
// If we successfully claimed the ownership of the slot,
// copy values to it.
if (claimed) {
new (&ent.value) T(val);
ent.keylen = key.size();
ent.key.store(key.data(), std::memory_order_release);
return {&ent.value, true};
}
// If someone is copying values to the slot, do busy wait.
while (ptr == (char *)-1) {
pause();
ptr = ent.key.load(std::memory_order_acquire);
}
// If the same key is already present, this is the slot we are
// looking for.
if (key == std::string_view(ptr, ent.keylen))
return {&ent.value, false};
}
std::cerr << "ConcurrentMap is full\n";
abort();
}
i64 get_idx(T *value) const {
uintptr_t addr = (uintptr_t)value - (uintptr_t)value % sizeof(Entry);
return (Entry *)addr - entries;
}
// Return a list of map entries sorted in a deterministic order.
std::vector<Entry *> get_sorted_entries(i64 shard_idx) {
if (nbuckets == 0)
return {};
i64 shard_size = nbuckets / NUM_SHARDS;
i64 begin = shard_idx * shard_size;
i64 end = begin + shard_size;
i64 sz = 0;
for (i64 i = begin; i < end; i++)
if (entries[i].key)
sz++;
std::vector<Entry *> vec;
vec.reserve(sz);
// Since the shard is circular, we need to handle the last entries
// as if they were next to the first entries.
while (begin < end && entries[end - 1].key)
vec.push_back(entries + --end);
// Find entries contiguous in the buckets and sort them.
i64 last = 0;
for (i64 i = begin; i < end;) {
while (i < end && entries[i].key)
vec.push_back(entries + i++);
std::sort(vec.begin() + last, vec.end(), [](Entry *a, Entry *b) {
if (a->keylen != b->keylen)
return a->keylen < b->keylen;
return memcmp(a->key, b->key, a->keylen) < 0;
});
last = vec.size();
while (i < end && !entries[i].key)
i++;
}
return vec;
}
std::vector<Entry *> get_sorted_entries_all() {
std::vector<std::vector<Entry *>> vec(NUM_SHARDS);
tbb::parallel_for((i64)0, NUM_SHARDS, [&](i64 i) {
vec[i] = get_sorted_entries(i);
});
return flatten(vec);
}
static constexpr i64 MIN_NBUCKETS = 4096;
static constexpr i64 NUM_SHARDS = 16;
static constexpr i64 MAX_RETRY = 256;
Entry *entries = nullptr;
u64 nbuckets = 0;
};
//
// random.cc
//
void get_random_bytes(u8 *buf, i64 size);
//
// hyperloglog.cc
//
class HyperLogLog {
public:
void insert(u64 hash) {
update_maximum(buckets[hash & (NBUCKETS - 1)], std::countl_zero(hash) + 1);
}
i64 get_cardinality() const;
void merge(const HyperLogLog &other) {
for (i64 i = 0; i < NBUCKETS; i++)
update_maximum(buckets[i], other.buckets[i]);
}
private:
static constexpr i64 NBUCKETS = 2048;
static constexpr double ALPHA = 0.79402;
Atomic<u8> buckets[NBUCKETS];
};
//
// aho-corasick.cc
//
class AhoCorasick {
public:
bool add(std::string_view pat, i64 val);
bool empty() const { return nodes.empty(); }
void compile();
i64 find(std::string_view str);
static bool can_handle(std::string_view str);
private:
struct TrieNode {
TrieNode() { children.fill(-1); }
i64 value = -1;
i32 suffix_link = -1;
std::array<i32, 256> children;
};
void fix_suffix_links(i64 idx);
void fix_values();
std::vector<TrieNode> nodes;
};
//
// glob.cc
//
class MultiGlob {
public:
bool add(std::string_view pat, i64 val);
bool empty() const { return patterns.empty(); }
void compile();
i64 find(std::string_view str);
struct State {
std::bitset<256> incoming_edge;
bool is_star = false;
};
struct GlobPattern {
std::vector<State> states;
i64 value = -1;
};
private:
std::vector<GlobPattern> patterns;
Bitvector start_states;
Bitvector star_mask;
Bitvector char_mask[256];
};
class Glob {
public:
bool add(std::string_view pat, i64 val);
bool empty() const { return multi_glob.empty() && aho_corasick.empty(); }
i64 find(std::string_view str);
private:
std::once_flag once;
bool is_compiled = false;
MultiGlob multi_glob;
AhoCorasick aho_corasick;
};
//
// filepath.cc
//
inline std::filesystem::path path_dirname(std::string_view path) {
return std::filesystem::path(path).parent_path();
}
inline std::string path_filename(std::string_view path) {
return std::filesystem::path(path).filename().string();
}
inline std::string path_clean(std::string_view path) {
return std::filesystem::path(path).lexically_normal().string();
}
std::string get_self_path();
//
// demangle.cc
//
std::optional<std::string_view> demangle_cpp(std::string_view name);
std::optional<std::string_view> demangle_rust(std::string_view name);
//
// crc32.cc
//
u32 compute_crc32(u32 crc, u8 *buf, i64 len);
std::vector<u8> crc32_solve(u32 current, u32 desired);
//
// compress.cc
//
class Compressor {
public:
virtual void write_to(u8 *buf) = 0;
virtual ~Compressor();
i64 compressed_size = 0;
protected:
std::vector<std::span<u8>> shards;
};
class ZlibCompressor : public Compressor {
public:
ZlibCompressor(u8 *buf, i64 size, i64 level);
void write_to(u8 *buf) override;
private:
u32 checksum = 0;
};
class ZstdCompressor : public Compressor {
public:
ZstdCompressor(u8 *buf, i64 size, i64 level);
void write_to(u8 *buf) override;
};
//
// tar.cc
//
// TarFile is a class to create a tar file.
//
// If you pass `--repro` to mold, mold collects all input files and
// put them into `<output-file-path>.repro.tar`, so that it is easy to
// run the same command with the same command line arguments.
class TarWriter {
public:
static std::unique_ptr<TarWriter>
open(std::string output_path, std::string basedir);
~TarWriter();
void append(std::string path, std::string_view data);
private:
TarWriter(FILE *out, std::string basedir) : out(out), basedir(basedir) {}
FILE *out = nullptr;
std::string basedir;
};
} // namespace mold
-20
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@@ -1,20 +0,0 @@
#include "lib.h"
#include <random>
namespace mold {
void get_random_bytes(u8 *buf, i64 size) {
std::random_device rand;
i64 i = 0;
for (; i < size - 4; i += 4) {
u32 val = rand();
memcpy(buf + i, &val, 4);
}
u32 val = rand();
memcpy(buf + i, &val, size - i);
}
} // namespace mold
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// This is a header-only C++20 implementation of SipHash based on the
// reference implementation. To use, just copy this header file into
// your project and #include it.
//
// https://github.com/rui314/siphash/blob/main/siphash.h
#include <bit>
#include <cstdint>
#include <cstring>
template <int C_ROUNDS, int D_ROUNDS, int OUTLEN>
class SipHashTmpl {
public:
static_assert(OUTLEN == 64 || OUTLEN == 128);
SipHashTmpl(void *key) {
uint64_t k0 = read64(key);
uint64_t k1 = read64((char *)key + 8);
v0 = 0x736f6d6570736575 ^ k0;
v1 = 0x646f72616e646f6d ^ k1;
v2 = 0x6c7967656e657261 ^ k0;
v3 = 0x7465646279746573 ^ k1;
if (OUTLEN == 128)
v1 ^= 0xee;
}
void update(void *msgp, int64_t msglen) {
char *msg = (char *)msgp;
sum += msglen;
if (buflen) {
if (buflen + msglen < 8) {
memcpy(buf + buflen, msg, msglen);
buflen += msglen;
return;
}
int j = 8 - buflen;
memcpy(buf + buflen, msg, j);
compress(read64(buf));
msg += j;
msglen -= j;
buflen = 0;
}
while (msglen >= 8) {
compress(read64(msg));
msg += 8;
msglen -= 8;
}
memcpy(buf, msg, msglen);
buflen = msglen;
}
void finish(void *out) {
memset(buf + buflen, 0, 8 - buflen);
compress(((uint64_t)sum << 56) | read64(buf));
v2 ^= (OUTLEN == 128) ? 0xee : 0xff;
finalize();
write64(out, v0 ^ v1 ^ v2 ^ v3);
if (OUTLEN == 128) {
v1 ^= 0xdd;
finalize();
write64((char *)out + 8, v0 ^ v1 ^ v2 ^ v3);
}
}
static void hash(void *out, void *key, void *in, int inlen) {
SipHashTmpl<C_ROUNDS, D_ROUNDS, OUTLEN> h(key);
h.update(in, inlen);
h.finish(out);
}
private:
uint64_t v0, v1, v2, v3;
uint8_t buf[8];
uint8_t buflen = 0;
uint8_t sum = 0;
uint64_t read64(void *loc) {
uint64_t val;
memcpy(&val, loc, 8);
if (std::endian::native == std::endian::big)
val = bswap(val);
return val;
}
void write64(void *loc, uint64_t val) {
if (std::endian::native == std::endian::big)
val = bswap(val);
memcpy(loc, &val, 8);
}
uint64_t bswap(uint64_t val) {
return ((val << 56) & 0xff00000000000000) |
((val << 40) & 0x00ff000000000000) |
((val << 24) & 0x0000ff0000000000) |
((val << 8) & 0x000000ff00000000) |
((val >> 8) & 0x00000000ff000000) |
((val >> 24) & 0x0000000000ff0000) |
((val >> 40) & 0x000000000000ff00) |
((val >> 56) & 0x00000000000000ff);
}
void round() {
v0 += v1;
v1 = std::rotl(v1, 13);
v1 ^= v0;
v0 = std::rotl(v0, 32);
v2 += v3;
v3 = std::rotl(v3, 16);
v3 ^= v2;
v0 += v3;
v3 = std::rotl(v3, 21);
v3 ^= v0;
v2 += v1;
v1 = std::rotl(v1, 17);
v1 ^= v2;
v2 = std::rotl(v2, 32);
}
void compress(uint64_t m) {
v3 ^= m;
for (int i = 0; i < C_ROUNDS; i++)
round();
v0 ^= m;
}
void finalize() {
for (int i = 0; i < D_ROUNDS; i++)
round();
}
};
using SipHash = SipHashTmpl<2, 4, 64>;
using SipHash128 = SipHashTmpl<2, 4, 128>;
using SipHash13 = SipHashTmpl<1, 3, 64>;
using SipHash13_128 = SipHashTmpl<1, 3, 128>;
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// This file contains functions to create a tar file.
#include "lib.h"
#ifdef _WIN32
# define ftruncate _chsize_s
#endif
namespace mold {
static constexpr i64 BLOCK_SIZE = 512;
// A tar file consists of one or more Ustar header followed by data.
// Each Ustar header represents a single file in an archive.
//
// tar is an old file format, and its `name` field is only 100 bytes long.
// If `name` is longer than 100 bytes, we can emit a PAX header before a
// Ustar header to store a long filename.
//
// For simplicity, we always emit a PAX header even for a short filename.
struct UstarHeader {
char name[100];
char mode[8];
char uid[8];
char gid[8];
char size[12];
char mtime[12];
char checksum[8];
char typeflag[1];
char linkname[100];
char magic[6];
char version[2];
char uname[32];
char gname[32];
char devmajor[8];
char devminor[8];
char prefix[155];
char pad[12];
};
static_assert(sizeof(UstarHeader) == BLOCK_SIZE);
static void finalize(UstarHeader &hdr) {
memset(hdr.checksum, ' ', sizeof(hdr.checksum));
memcpy(hdr.magic, "ustar", 5);
memcpy(hdr.version, "00", 2);
// Compute checksum
int sum = 0;
for (i64 i = 0; i < sizeof(hdr); i++)
sum += ((u8 *)&hdr)[i];
// We need to convince the compiler that sum isn't too big to silence
// -Werror=format-truncation.
if (sum >= 01'000'000)
unreachable();
snprintf(hdr.checksum, sizeof(hdr.checksum), "%06o", sum);
}
static std::string encode_path(std::string basedir, std::string path) {
path = path_clean(basedir + "/" + path);
// Construct a string which contains something like
// "16 path=foo/bar\n" where 16 is the size of the string
// including the size string itself.
i64 len = std::string(" path=\n").size() + path.size();
i64 total = std::to_string(len).size() + len;
total = std::to_string(total).size() + len;
return std::to_string(total) + " path=" + path + "\n";
}
std::unique_ptr<TarWriter>
TarWriter::open(std::string output_path, std::string basedir) {
FILE *out = fopen(output_path.c_str(), "w");
if (!out)
return nullptr;
return std::unique_ptr<TarWriter>(new TarWriter(out, basedir));
}
TarWriter::~TarWriter() {
fclose(out);
}
void TarWriter::append(std::string path, std::string_view data) {
// Write PAX header
UstarHeader pax = {};
std::string attr = encode_path(basedir, path);
if (attr.size() >= 0100'000'000'000)
unreachable();
snprintf(pax.size, sizeof(pax.size), "%011zo", attr.size());
pax.name[0] = '/';
pax.typeflag[0] = 'x';
finalize(pax);
fwrite(&pax, sizeof(pax), 1, out);
// Write pathname
fwrite(attr.data(), attr.size(), 1, out);
fseek(out, align_to(ftell(out), BLOCK_SIZE), SEEK_SET);
// Write Ustar header
UstarHeader ustar = {};
memcpy(ustar.mode, "0000664", 8);
if (data.size() >= 0100'000'000'000)
unreachable();
snprintf(ustar.size, sizeof(ustar.size), "%011zo", data.size());
finalize(ustar);
fwrite(&ustar, sizeof(ustar), 1, out);
// Write file contents
fwrite(data.data(), data.size(), 1, out);
fseek(out, align_to(ftell(out), BLOCK_SIZE), SEEK_SET);
// A tar file must ends with two empty blocks
(void)!ftruncate(fileno(out), ftell(out) + BLOCK_SIZE * 2);
}
} // namespace mold
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@@ -1,33 +0,0 @@
# Get a git hash value. We do not want to use git command here
# because we don't want to make git a build-time dependency.
if(EXISTS "${SOURCE_DIR}/.git/HEAD")
file(READ "${SOURCE_DIR}/.git/HEAD" HASH)
string(STRIP "${HASH}" HASH)
if(HASH MATCHES "^ref: (.*)")
set(HEAD "${CMAKE_MATCH_1}")
if(EXISTS "${SOURCE_DIR}/.git/${HEAD}")
file(READ "${SOURCE_DIR}/.git/${HEAD}" HASH)
string(STRIP "${HASH}" HASH)
else()
file(READ "${SOURCE_DIR}/.git/packed-refs" PACKED_REFS)
string(REGEX REPLACE ".*\n([0-9a-f]+) ${HEAD}\n.*" "\\1" HASH "\n${PACKED_REFS}")
endif()
endif()
endif()
# Create new file contents and update a given file if necessary.
if("${HASH}" STREQUAL "")
set(NEW_CONTENTS "")
else()
set(NEW_CONTENTS "#define MOLD_GIT_HASH \"${HASH}\"\n")
endif()
if(EXISTS "${OUTPUT_FILE}")
file(READ "${OUTPUT_FILE}" OLD_CONTENTS)
if(NOT "${NEW_CONTENTS}" STREQUAL "${OLD_CONTENTS}")
file(WRITE "${OUTPUT_FILE}" "${NEW_CONTENTS}")
endif()
else()
file(WRITE "${OUTPUT_FILE}" "${NEW_CONTENTS}")
endif()
+364
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@@ -0,0 +1,364 @@
// On Linux, /usr/lib/x86_64-linux-gnu/libc.so is not actually
// a shared object file but an ASCII text file containing a linker
// script to include a "real" libc.so file. Therefore, we need to
// support a (very limited) subset of the linker script language.
#include "mold.h"
#include <cctype>
#include <iomanip>
template <typename E>
static thread_local MemoryMappedFile<E> *current_file;
static std::string_view get_line(std::string_view input, const char *pos) {
assert(input.data() <= pos);
assert(pos < input.data() + input.size());
i64 start = input.rfind('\n', pos - input.data());
if (start == input.npos)
start = 0;
else
start++;
i64 end = input.find('\n', pos - input.data());
if (end == input.npos)
end = input.size();
return input.substr(start, end - start);
}
template <typename E>
class SyntaxError {
public:
SyntaxError(Context<E> &ctx, std::string_view errpos) : out(ctx) {
std::string_view contents = current_file<E>->get_contents(ctx);
std::string_view line = get_line(contents, errpos.data());
i64 lineno = 1;
for (i64 i = 0; contents.data() + i < line.data(); i++)
if (contents[i] == '\n')
lineno++;
i64 column = errpos.data() - line.data();
std::stringstream ss;
ss << current_file<E>->name << ":" << lineno << ": ";
i64 indent = (i64)ss.tellp() + strlen("mold: ");
ss << line << "\n" << std::setw(indent + column) << " " << "^ ";
out << ss.str();
}
template <class T> SyntaxError &operator<<(T &&val) {
out << std::forward<T>(val);
return *this;
}
[[noreturn]] ~SyntaxError() = default;
Fatal<E> out;
};
template <typename E>
static std::vector<std::string_view>
tokenize(Context<E> &ctx, std::string_view input) {
std::vector<std::string_view> vec;
while (!input.empty()) {
if (isspace(input[0])) {
input = input.substr(1);
continue;
}
if (input.starts_with("/*")) {
i64 pos = input.find("*/", 2);
if (pos == std::string_view::npos)
SyntaxError(ctx, input) << "unclosed comment";
input = input.substr(pos + 2);
continue;
}
if (input[0] == '#') {
i64 pos = input.find("\n", 1);
if (pos == std::string_view::npos)
break;
input = input.substr(pos + 1);
continue;
}
if (input[0] == '"') {
i64 pos = input.find('"', 1);
if (pos == std::string_view::npos)
SyntaxError(ctx, input) << "unclosed string literal";
vec.push_back(input.substr(0, pos + 1));
input = input.substr(pos + 1);
continue;
}
i64 pos = input.find_first_not_of(
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
"0123456789_.$/\\~=+[]*?-!^:");
if (pos == 0)
pos = 1;
else if (pos == input.npos)
pos = input.size();
vec.push_back(input.substr(0, pos));
input = input.substr(pos);
}
return vec;
}
template <typename E>
static std::span<std::string_view>
skip(Context<E> &ctx, std::span<std::string_view> tok, std::string_view str) {
if (tok.empty())
Fatal(ctx) << current_file<E>->name << ": expected '" << str
<< "', but got EOF";
if (tok[0] != str)
SyntaxError(ctx, tok[0]) << "expected '" << str << "'";
return tok.subspan(1);
}
static std::string_view unquote(std::string_view s) {
if (s.size() > 0 && s[0] == '"') {
assert(s[s.size() - 1] == '"');
return s.substr(1, s.size() - 2);
}
return s;
}
template <typename E>
static std::span<std::string_view>
read_output_format(Context<E> &ctx, std::span<std::string_view> tok) {
tok = skip(ctx, tok, "(");
while (!tok.empty() && tok[0] != ")")
tok = tok.subspan(1);
if (tok.empty())
Fatal(ctx) << current_file<E>->name << ": expected ')', but got EOF";
return tok.subspan(1);
}
template <typename E>
static MemoryMappedFile<E> *resolve_path(Context<E> &ctx, std::string_view tok) {
std::string str(unquote(tok));
if (str.starts_with("/"))
return MemoryMappedFile<E>::must_open(ctx, ctx.arg.sysroot + str);
if (str.starts_with("-l"))
return find_library(ctx, str.substr(2));
if (std::string dir(path_dirname(current_file<E>->name));
MemoryMappedFile<E> *mb = MemoryMappedFile<E>::open(ctx, dir + "/" + str))
return mb;
if (MemoryMappedFile<E> *mb = MemoryMappedFile<E>::open(ctx, str))
return mb;
for (std::string_view dir : ctx.arg.library_paths) {
std::string root = dir.starts_with("/") ? ctx.arg.sysroot : "";
std::string path = root + std::string(dir) + "/" + str;
if (MemoryMappedFile<E> *mb = MemoryMappedFile<E>::open(ctx, path))
return mb;
}
SyntaxError(ctx, tok) << "library not found: " << str;
}
template <typename E>
static std::span<std::string_view>
read_group(Context<E> &ctx, std::span<std::string_view> tok) {
tok = skip(ctx, tok, "(");
while (!tok.empty() && tok[0] != ")") {
if (tok[0] == "AS_NEEDED") {
bool orig = ctx.as_needed;
ctx.as_needed = true;
tok = read_group(ctx, tok.subspan(1));
ctx.as_needed = orig;
continue;
}
MemoryMappedFile<E> *mb = resolve_path(ctx, tok[0]);
read_file(ctx, mb);
tok = tok.subspan(1);
}
if (tok.empty())
Fatal(ctx) << current_file<E>->name << ": expected ')', but got EOF";
return tok.subspan(1);
}
template <typename E>
void parse_linker_script(Context<E> &ctx, MemoryMappedFile<E> *mb) {
current_file<E> = mb;
std::vector<std::string_view> vec = tokenize(ctx, mb->get_contents(ctx));
std::span<std::string_view> tok = vec;
while (!tok.empty()) {
if (tok[0] == "OUTPUT_FORMAT")
tok = read_output_format(ctx, tok.subspan(1));
else if (tok[0] == "INPUT" || tok[0] == "GROUP")
tok = read_group(ctx, tok.subspan(1));
else
SyntaxError(ctx, tok[0]) << "unknown token";
}
}
template <typename E>
i64 get_script_output_type(Context<E> &ctx, MemoryMappedFile<E> *mb) {
current_file<E> = mb;
std::vector<std::string_view> vec = tokenize(ctx, mb->get_contents(ctx));
std::span<std::string_view> tok = vec;
if (tok.size() >= 3 && tok[0] == "OUTPUT_FORMAT" && tok[1] == "(") {
if (tok[2] == "elf64-x86-64")
return EM_X86_64;
if (tok[2] == "elf32-i386")
return EM_386;
}
return -1;
}
static bool read_label(std::span<std::string_view> &tok,
std::string label) {
if (tok.size() >= 1 && tok[0] == label + ":") {
tok = tok.subspan(1);
return true;
}
if (tok.size() >= 2 && tok[0] == label && tok[1] == ":") {
tok = tok.subspan(2);
return true;
}
return false;
}
template <typename E>
static void parse_version_script_commands(Context<E> &ctx,
std::span<std::string_view> &tok,
i16 &ver, bool is_extern_cpp) {
bool is_global = true;
while (!tok.empty() && tok[0] != "}") {
if (read_label(tok, "global")) {
is_global = true;
continue;
}
if (read_label(tok, "local")) {
is_global = false;
continue;
}
if (tok[0] == "extern") {
tok = tok.subspan(1);
bool is_cpp;
if (!tok.empty() && tok[0] == "\"C\"") {
tok = tok.subspan(1);
is_cpp = false;
} else {
tok = skip(ctx, tok, "\"C++\"");
is_cpp = true;
}
tok = skip(ctx, tok, "{");
parse_version_script_commands(ctx, tok, ver, is_cpp);
tok = skip(ctx, tok, "}");
tok = skip(ctx, tok, ";");
continue;
}
if (tok[0] == "*")
ctx.arg.default_version = (is_global ? ver : VER_NDX_LOCAL);
else
ctx.arg.version_patterns.push_back({tok[0], ver, is_extern_cpp});
tok = tok.subspan(1);
if (!tok.empty() && tok[0] == "}")
return;
tok = skip(ctx, tok, ";");
}
}
template <typename E>
void parse_version_script(Context<E> &ctx, std::string path) {
current_file<E> = MemoryMappedFile<E>::must_open(ctx, path);
std::vector<std::string_view> vec =
tokenize(ctx, current_file<E>->get_contents(ctx));
std::span<std::string_view> tok = vec;
i16 next_ver = VER_NDX_LAST_RESERVED + 1;
while (!tok.empty()) {
i16 ver = VER_NDX_GLOBAL;
if (tok[0] != "{") {
ver = next_ver++;
ctx.arg.version_definitions.push_back(tok[0]);
tok = tok.subspan(1);
}
tok = skip(ctx, tok, "{");
parse_version_script_commands(ctx, tok, ver, false);
tok = skip(ctx, tok, "}");
if (!tok.empty() && tok[0] != ";")
tok = tok.subspan(1);
tok = skip(ctx, tok, ";");
}
if (!tok.empty())
SyntaxError(ctx, tok[0]) << "trailing garbage token";
}
template <typename E>
void parse_dynamic_list(Context<E> &ctx, std::string path) {
current_file<E> = MemoryMappedFile<E>::must_open(ctx, path);
std::vector<std::string_view> vec =
tokenize(ctx, current_file<E>->get_contents(ctx));
std::span<std::string_view> tok = vec;
tok = skip(ctx, tok, "{");
i16 ver = VER_NDX_GLOBAL;
while (!tok.empty() && tok[0] != "}") {
if (read_label(tok, "global")) {
ver = VER_NDX_GLOBAL;
continue;
}
if (read_label(tok, "local")) {
ver = VER_NDX_LOCAL;
continue;
}
if (tok[0] == "*")
ctx.arg.default_version = ver;
else
ctx.arg.version_patterns.push_back({tok[0], ver, false});
tok = skip(ctx, tok.subspan(1), ";");
}
tok = skip(ctx, tok, "}");
tok = skip(ctx, tok, ";");
if (!tok.empty())
SyntaxError(ctx, tok[0]) << "trailing garbage token";
}
#define INSTANTIATE(E) \
template \
void parse_linker_script(Context<E> &ctx, MemoryMappedFile<E> *mb); \
template \
i64 get_script_output_type(Context<E> &ctx, MemoryMappedFile<E> *mb); \
template \
void parse_version_script(Context<E> &ctx, std::string path); \
template \
void parse_dynamic_list(Context<E> &ctx, std::string path)
INSTANTIATE(X86_64);
INSTANTIATE(I386);
+682
View File
@@ -0,0 +1,682 @@
#include "mold.h"
#include <functional>
#include <iomanip>
#include <map>
#include <signal.h>
#include <tbb/global_control.h>
#include <tbb/parallel_for_each.h>
#include <unistd.h>
#include <unordered_set>
template <typename E>
std::string_view save_string(Context<E> &ctx, const std::string &str) {
u8 *buf = new u8[str.size() + 1];
memcpy(buf, str.data(), str.size());
buf[str.size()] = '\0';
ctx.owning_bufs.push_back(std::unique_ptr<u8[]>(buf));
return {(char *)buf, str.size()};
}
std::string get_version_string() {
if (strlen(GIT_HASH) == 0)
return "mold " MOLD_VERSION " (compatible with GNU ld and GNU gold)";
return "mold " MOLD_VERSION " (" GIT_HASH
"; compatible with GNU ld and GNU gold)";
}
std::regex glob_to_regex(std::string_view pattern) {
std::stringstream ss;
for (u8 c : pattern) {
if (c == '*')
ss << ".*";
else
ss << "\\x" << std::hex << std::setw(2) << std::setfill('0') << (int)c;
}
return std::regex(ss.str(), std::regex::optimize);
}
template <typename E>
static ObjectFile<E> *new_object_file(Context<E> &ctx, MemoryMappedFile<E> *mb,
std::string archive_name) {
static Counter count("parsed_objs");
count++;
bool in_lib = (!archive_name.empty() && !ctx.whole_archive);
ObjectFile<E> *file = ObjectFile<E>::create(ctx, mb, archive_name, in_lib);
file->priority = ctx.file_priority++;
ctx.tg.run([file, &ctx]() { file->parse(ctx); });
if (ctx.arg.trace)
SyncOut(ctx) << "trace: " << *file;
return file;
}
template <typename E>
static SharedFile<E> *new_shared_file(Context<E> &ctx, MemoryMappedFile<E> *mb) {
SharedFile<E> *file = SharedFile<E>::create(ctx, mb);
file->priority = ctx.file_priority++;
ctx.tg.run([file, &ctx]() { file->parse(ctx); });
if (ctx.arg.trace)
SyncOut(ctx) << "trace: " << *file;
return file;
}
template <typename E>
void read_file(Context<E> &ctx, MemoryMappedFile<E> *mb) {
if (ctx.visited.contains(mb->name))
return;
if (ctx.is_preloading) {
switch (get_file_type(ctx, mb)) {
case FileType::OBJ:
ctx.obj_cache.store(mb, new_object_file(ctx, mb, ""));
return;
case FileType::DSO:
ctx.dso_cache.store(mb, new_shared_file(ctx, mb));
return;
case FileType::AR:
for (MemoryMappedFile<E> *child : read_fat_archive_members(ctx, mb))
if (get_file_type(ctx, child) == FileType::OBJ)
ctx.obj_cache.store(mb, new_object_file(ctx, child, mb->name));
return;
case FileType::THIN_AR:
for (MemoryMappedFile<E> *child : read_thin_archive_members(ctx, mb))
if (get_file_type(ctx, child) == FileType::OBJ)
ctx.obj_cache.store(child, new_object_file(ctx, child, mb->name));
return;
case FileType::TEXT:
parse_linker_script(ctx, mb);
return;
case FileType::LLVM_BITCODE:
Fatal(ctx) << mb->name << ": looks like this is an LLVM bitcode, but"
<< " mold does not support LTO";
default:
Fatal(ctx) << mb->name << ": unknown file type";
}
}
switch (get_file_type(ctx, mb)) {
case FileType::OBJ:
if (ObjectFile<E> *obj = ctx.obj_cache.get_one(mb))
ctx.objs.push_back(obj);
else
ctx.objs.push_back(new_object_file(ctx, mb, ""));
return;
case FileType::DSO:
if (SharedFile<E> *obj = ctx.dso_cache.get_one(mb))
ctx.dsos.push_back(obj);
else
ctx.dsos.push_back(new_shared_file(ctx, mb));
ctx.visited.insert(mb->name);
return;
case FileType::AR: {
std::vector<ObjectFile<E> *> objs = ctx.obj_cache.get(mb);
if (!objs.empty()) {
append(ctx.objs, objs);
} else {
for (MemoryMappedFile<E> *child : read_fat_archive_members(ctx, mb))
if (get_file_type(ctx, child) == FileType::OBJ)
ctx.objs.push_back(new_object_file(ctx, child, mb->name));
}
ctx.visited.insert(mb->name);
return;
}
case FileType::THIN_AR:
for (MemoryMappedFile<E> *child : read_thin_archive_members(ctx, mb)) {
if (ObjectFile<E> *obj = ctx.obj_cache.get_one(child))
ctx.objs.push_back(obj);
else if (get_file_type(ctx, child) == FileType::OBJ)
ctx.objs.push_back(new_object_file(ctx, child, mb->name));
}
ctx.visited.insert(mb->name);
return;
case FileType::TEXT:
parse_linker_script(ctx, mb);
return;
case FileType::LLVM_BITCODE:
Fatal(ctx) << mb->name << ": looks like this is an LLVM bitcode, "
<< "but mold does not support LTO";
default:
Fatal(ctx) << mb->name << ": unknown file type";
}
}
template <typename E>
void cleanup() {
if (OutputFile<E>::tmpfile)
unlink(OutputFile<E>::tmpfile);
if (socket_tmpfile)
unlink(socket_tmpfile);
}
template <typename E>
static void signal_handler(int) {
cleanup<E>();
_exit(1);
}
// Read the beginning of a given file and returns its machine type
// (e.g. EM_X86_64 or EM_386). Return -1 if unknown.
template <typename E>
static i64 get_machine_type(Context<E> &ctx, MemoryMappedFile<E> *mb) {
switch (get_file_type(ctx, mb)) {
case FileType::DSO:
return ((ElfEhdr<E> *)mb->data(ctx))->e_machine;
case FileType::AR:
for (MemoryMappedFile<E> *child : read_fat_archive_members(ctx, mb))
if (get_file_type(ctx, child) == FileType::OBJ)
return ((ElfEhdr<E> *)child->data(ctx))->e_machine;
return -1;
case FileType::THIN_AR:
for (MemoryMappedFile<E> *child : read_thin_archive_members(ctx, mb))
if (get_file_type(ctx, child) == FileType::OBJ)
return ((ElfEhdr<E> *)child->data(ctx))->e_machine;
return -1;
case FileType::TEXT:
return get_script_output_type(ctx, mb);
default:
return -1;
}
}
template <typename E>
static MemoryMappedFile<E> *open_library(Context<E> &ctx, std::string path) {
MemoryMappedFile<E> *mb = MemoryMappedFile<E>::open(ctx, path);
if (!mb)
return nullptr;
i64 type = get_machine_type(ctx, mb);
if (type == -1 || type == E::e_machine)
return mb;
Warn(ctx) << path << ": skipping incompatible file";
return nullptr;
}
template <typename E>
MemoryMappedFile<E> *find_library(Context<E> &ctx, std::string name) {
if (name.starts_with(':')) {
for (std::string_view dir : ctx.arg.library_paths) {
std::string root = dir.starts_with("/") ? ctx.arg.sysroot : "";
std::string path = root + std::string(dir) + "/" + name.substr(1);
if (MemoryMappedFile<E> *mb = open_library(ctx, path))
return mb;
}
Fatal(ctx) << "library not found: " << name;
}
for (std::string_view dir : ctx.arg.library_paths) {
std::string root = dir.starts_with("/") ? ctx.arg.sysroot : "";
std::string stem = root + std::string(dir) + "/lib" + name;
if (!ctx.is_static)
if (MemoryMappedFile<E> *mb = open_library(ctx, stem + ".so"))
return mb;
if (MemoryMappedFile<E> *mb = open_library(ctx, stem + ".a"))
return mb;
}
Fatal(ctx) << "library not found: " << name;
}
template <typename E>
static void read_input_files(Context<E> &ctx, std::span<std::string_view> args) {
std::vector<std::tuple<bool, bool, bool>> state;
while (!args.empty()) {
std::string_view arg;
if (read_flag(args, "as-needed")) {
ctx.as_needed = true;
} else if (read_flag(args, "no-as-needed")) {
ctx.as_needed = false;
} else if (read_flag(args, "whole-archive")) {
ctx.whole_archive = true;
} else if (read_flag(args, "no-whole-archive")) {
ctx.whole_archive = false;
} else if (read_flag(args, "Bstatic")) {
ctx.is_static = true;
} else if (read_flag(args, "Bdynamic")) {
ctx.is_static = false;
} else if (read_arg(ctx, args, arg, "version-script")) {
parse_version_script(ctx, std::string(arg));
} else if (read_arg(ctx, args, arg, "dynamic-list")) {
parse_dynamic_list(ctx, std::string(arg));
} else if (read_flag(args, "push-state")) {
state.push_back({ctx.as_needed, ctx.whole_archive, ctx.is_static});
} else if (read_flag(args, "pop-state")) {
if (state.empty())
Fatal(ctx) << "no state pushed before popping";
std::tie(ctx.as_needed, ctx.whole_archive, ctx.is_static) = state.back();
state.pop_back();
} else if (read_arg(ctx, args, arg, "l")) {
MemoryMappedFile<E> *mb = find_library(ctx, std::string(arg));
mb->given_fullpath = false;
read_file(ctx, mb);
} else {
read_file(ctx, MemoryMappedFile<E>::must_open(ctx, std::string(args[0])));
args = args.subspan(1);
}
}
}
template <typename E>
static void show_stats(Context<E> &ctx) {
for (ObjectFile<E> *obj : ctx.objs) {
static Counter defined("defined_syms");
defined += obj->first_global - 1;
static Counter undefined("undefined_syms");
undefined += obj->symbols.size() - obj->first_global;
for (std::unique_ptr<InputSection<E>> &sec : obj->sections) {
if (!sec || !sec->is_alive)
continue;
static Counter alloc("reloc_alloc");
static Counter nonalloc("reloc_nonalloc");
if (sec->shdr.sh_flags & SHF_ALLOC)
alloc += sec->get_rels(ctx).size();
else
nonalloc += sec->get_rels(ctx).size();
}
static Counter comdats("comdats");
comdats += obj->comdat_groups.size();
static Counter removed_comdats("removed_comdat_mem");
for (auto &pair : obj->comdat_groups)
if (ComdatGroup *group = pair.first; group->owner != obj->priority)
removed_comdats += pair.second.size();
static Counter num_cies("num_cies");
num_cies += obj->cies.size();
static Counter num_unique_cies("num_unique_cies");
for (CieRecord<E> &cie : obj->cies)
if (cie.is_leader)
num_unique_cies++;
static Counter num_fdes("num_fdes");
num_fdes += obj->fdes.size();
}
static Counter num_bytes("total_input_bytes");
for (std::unique_ptr<MemoryMappedFile<E>> &mb : ctx.owning_mbs)
num_bytes += mb->size();
static Counter num_input_sections("input_sections");
for (ObjectFile<E> *file : ctx.objs)
num_input_sections += file->sections.size();
static Counter num_output_chunks("output_chunks", ctx.chunks.size());
static Counter num_objs("num_objs", ctx.objs.size());
static Counter num_dsos("num_dsos", ctx.dsos.size());
Counter::print();
}
template <typename E>
int do_main(int argc, char **argv) {
Context<E> ctx;
// Process -run option first. process_run_subcommand() does not return.
if (argc >= 2)
if (std::string_view arg = argv[1]; arg == "-run" || arg == "--run")
process_run_subcommand(ctx, argc, argv);
Timer t_all(ctx, "all");
// Parse non-positional command line options
ctx.cmdline_args = expand_response_files(ctx, argv);
std::vector<std::string_view> file_args;
parse_nonpositional_args(ctx, file_args);
if (ctx.arg.relocatable) {
combine_objects(ctx, file_args);
return 0;
}
if (!ctx.arg.preload)
try_resume_daemon(ctx);
tbb::global_control tbb_cont(tbb::global_control::max_allowed_parallelism,
ctx.arg.thread_count);
signal(SIGINT, signal_handler<E>);
signal(SIGTERM, signal_handler<E>);
if (!ctx.arg.directory.empty() && chdir(ctx.arg.directory.c_str()) == -1)
Fatal(ctx) << "chdir failed: " << ctx.arg.directory
<< ": " << strerror(errno);
// Handle --wrap options if any.
for (std::string_view name : ctx.arg.wrap)
Symbol<E>::intern(ctx, name)->wrap = true;
// Handle --retain-symbols-file options if any.
if (ctx.arg.retain_symbols_file)
for (std::string_view name : *ctx.arg.retain_symbols_file)
Symbol<E>::intern(ctx, name)->write_to_symtab = true;
// Preload input files
std::function<void()> on_complete;
if (ctx.arg.preload) {
Timer t(ctx, "preload");
std::function<void()> wait_for_client;
daemonize(ctx, &wait_for_client, &on_complete);
ctx.reset_reader_context(true);
read_input_files(ctx, file_args);
ctx.tg.wait();
t.stop();
Timer t2(ctx, "wait_for_client");
wait_for_client();
} else if (ctx.arg.fork) {
on_complete = fork_child();
}
for (std::string_view arg : ctx.arg.trace_symbol)
Symbol<E>::intern(ctx, arg)->traced = true;
// Parse input files
{
Timer t(ctx, "parse");
ctx.reset_reader_context(false);
read_input_files(ctx, file_args);
ctx.tg.wait();
}
if (ctx.objs.empty())
Fatal(ctx) << "no input files";
// Uniquify shared object files by soname
{
std::unordered_set<std::string_view> seen;
erase(ctx.dsos, [&](SharedFile<E> *file) {
return !seen.insert(file->soname).second;
});
}
Timer t_total(ctx, "total");
Timer t_before_copy(ctx, "before_copy");
// Apply -exclude-libs
apply_exclude_libs(ctx);
// Create instances of linker-synthesized sections such as
// .got or .plt.
create_synthetic_sections(ctx);
// Resolve symbols and fix the set of object files that are
// included to the final output.
resolve_symbols(ctx);
// Remove redundant comdat sections (e.g. duplicate inline functions).
eliminate_comdats(ctx);
// Create .bss sections for common symbols.
convert_common_symbols(ctx);
// Apply version scripts.
apply_version_script(ctx);
// Parse symbol version suffixes (e.g. "foo@ver1").
parse_symbol_version(ctx);
// Set is_import and is_export bits for each symbol.
compute_import_export(ctx);
// Garbage-collect unreachable sections.
if (ctx.arg.gc_sections)
gc_sections(ctx);
// Merge identical read-only sections.
if (ctx.arg.icf)
icf_sections(ctx);
// Compute sizes of sections containing mergeable strings.
compute_merged_section_sizes(ctx);
// ctx input sections into output sections
bin_sections(ctx);
// Get a list of output sections.
append(ctx.chunks, collect_output_sections(ctx));
// Create a dummy file containing linker-synthesized symbols
// (e.g. `__bss_start`).
ctx.internal_obj = ObjectFile<E>::create_internal_file(ctx);
ctx.internal_obj->resolve_regular_symbols(ctx);
ctx.objs.push_back(ctx.internal_obj);
// Beyond this point, no new files will be added to ctx.objs
// or ctx.dsos.
// If we are linking a .so file, remaining undefined symbols does
// not cause a linker error. Instead, they are treated as if they
// were imported symbols.
//
// If we are linking an executable, weak undefs are converted to
// weakly imported symbol so that they'll have another chance to be
claim_unresolved_symbols(ctx);
// Beyond this point, no new symbols will be added to the result.
// Make sure that all symbols have been resolved.
if (!ctx.arg.allow_multiple_definition)
check_duplicate_symbols(ctx);
// .init_array and .fini_array contents have to be sorted by
// a special rule. Sort them.
sort_init_fini(ctx);
// Compute sizes of output sections while assigning offsets
// within an output section to input sections.
compute_section_sizes(ctx);
// Sort sections by section attributes so that we'll have to
// create as few segments as possible.
sort(ctx.chunks, [&](OutputChunk<E> *a, OutputChunk<E> *b) {
return get_section_rank(ctx, a) < get_section_rank(ctx, b);
});
// Copy string referred by .dynamic to .dynstr.
for (SharedFile<E> *file : ctx.dsos)
ctx.dynstr->add_string(file->soname);
for (std::string_view str : ctx.arg.auxiliary)
ctx.dynstr->add_string(str);
for (std::string_view str : ctx.arg.filter)
ctx.dynstr->add_string(str);
if (!ctx.arg.rpaths.empty())
ctx.dynstr->add_string(ctx.arg.rpaths);
if (!ctx.arg.soname.empty())
ctx.dynstr->add_string(ctx.arg.soname);
// Scan relocations to find symbols that need entries in .got, .plt,
// .got.plt, .dynsym, .dynstr, etc.
scan_rels(ctx);
// Reserve a space for dynamic symbol strings in .dynstr and sort
// .dynsym contents if necessary. Beyond this point, no symbol will
// be added to .dynsym.
ctx.dynsym->finalize(ctx);
// Fill .gnu.version_d section contents.
ctx.verdef->construct(ctx);
// Fill .gnu.version_r section contents.
ctx.verneed->construct(ctx);
// Compute .symtab and .strtab sizes for each file.
{
Timer t(ctx, "compute_symtab");
tbb::parallel_for_each(ctx.objs, [&](ObjectFile<E> *file) {
file->compute_symtab(ctx);
});
}
// .eh_frame is a special section from the linker's point of view,
// as its contents are parsed and reconstructed by the linker,
// unlike other sections that are regarded as opaque bytes.
// Here, we transplant .eh_frame sections from a regular output
// section to the special EHFrameSection.
{
Timer t(ctx, "eh_frame");
erase(ctx.chunks, [](OutputChunk<E> *chunk) {
return chunk->kind == OutputChunk<E>::REGULAR &&
chunk->name == ".eh_frame";
});
ctx.eh_frame->construct(ctx);
}
// Now that we have computed sizes for all sections and assigned
// section indices to them, so we can fix section header contents
// for all output sections.
for (OutputChunk<E> *chunk : ctx.chunks)
chunk->update_shdr(ctx);
erase(ctx.chunks, [](OutputChunk<E> *chunk) {
return chunk->kind == OutputChunk<E>::SYNTHETIC &&
chunk->shdr.sh_size == 0;
});
// Set section indices.
for (i64 i = 0, shndx = 1; i < ctx.chunks.size(); i++)
if (ctx.chunks[i]->kind != OutputChunk<E>::HEADER)
ctx.chunks[i]->shndx = shndx++;
for (OutputChunk<E> *chunk : ctx.chunks)
chunk->update_shdr(ctx);
// Assign offsets to output sections
i64 filesize = set_osec_offsets(ctx);
// Fix linker-synthesized symbol addresses.
fix_synthetic_symbols(ctx);
// If --compress-debug-sections is given, compress .debug_* sections
// using zlib.
if (ctx.arg.compress_debug_sections != COMPRESS_NONE) {
compress_debug_sections(ctx);
filesize = set_osec_offsets(ctx);
}
// At this point, file layout is fixed.
// Beyond this, you can assume that symbol addresses including their
// GOT or PLT addresses have a correct final value.
// Some types of relocations for TLS symbols need the TLS segment
// address. Find it out now.
for (ElfPhdr<E> phdr : create_phdr(ctx)) {
if (phdr.p_type == PT_TLS) {
ctx.tls_begin = phdr.p_vaddr;
ctx.tls_end = align_to(phdr.p_vaddr + phdr.p_memsz, phdr.p_align);
break;
}
}
t_before_copy.stop();
// Create an output file
ctx.output_file = OutputFile<E>::open(ctx, ctx.arg.output, filesize, 0777);
ctx.buf = ctx.output_file->buf;
Timer t_copy(ctx, "copy");
// Copy input sections to the output file
{
Timer t(ctx, "copy_buf");
tbb::parallel_for_each(ctx.chunks, [&](OutputChunk<E> *chunk) {
std::string name(chunk->name);
if (name.empty())
name = "(header)";
Timer t2(ctx, name, &t);
chunk->copy_buf(ctx);
});
Error<E>::checkpoint(ctx);
}
// Dynamic linker works better with sorted .rela.dyn section,
// so we sort them.
ctx.reldyn->sort(ctx);
// Zero-clear paddings between sections
clear_padding(ctx);
if (ctx.buildid) {
Timer t(ctx, "build_id");
ctx.buildid->write_buildid(ctx);
}
t_copy.stop();
// Commit
ctx.output_file->close(ctx);
t_total.stop();
t_all.stop();
if (ctx.arg.print_map)
print_map(ctx);
// Show stats numbers
if (ctx.arg.stats)
show_stats(ctx);
if (ctx.arg.perf)
Timer<E>::print(ctx);
std::cout << std::flush;
std::cerr << std::flush;
if (on_complete)
on_complete();
if (ctx.arg.quick_exit)
std::quick_exit(0);
for (std::function<void()> &fn : ctx.on_exit)
fn();
return 0;
}
enum class MachineType { X86_64, I386 };
static MachineType get_machine_type(int argc, char **argv) {
for (i64 i = 1; i < argc; i++) {
if (std::string_view(argv[i]) == "-m") {
if (i + 1 == argc)
break;
i++;
std::string_view val(argv[i]);
if (val == "elf_x86_64")
return MachineType::X86_64;
if (val == "elf_i386")
return MachineType::I386;
std::cerr << "unknown -m argument: " << val << "\n";
exit(1);
}
}
return MachineType::X86_64;
}
int main(int argc, char **argv) {
switch (get_machine_type(argc, argv)) {
case MachineType::X86_64:
return do_main<X86_64>(argc, argv);
case MachineType::I386:
return do_main<I386>(argc, argv);
}
}
#define INSTANTIATE(E) \
template void read_file(Context<E> &, MemoryMappedFile<E> *); \
template std::string_view save_string(Context<E> &, const std::string &)
INSTANTIATE(X86_64);
INSTANTIATE(I386);
+104
View File
@@ -0,0 +1,104 @@
#include "mold.h"
#include <fstream>
#include <iomanip>
#include <ios>
#include <sstream>
#include <tbb/parallel_for_each.h>
#include <unordered_map>
template <typename E>
using Map =
tbb::concurrent_hash_map<InputSection<E> *, std::vector<Symbol<E> *>>;
template <typename E>
static std::unique_ptr<std::ofstream> open_output_file(Context<E> &ctx) {
std::unique_ptr<std::ofstream> file(new std::ofstream);
file->open(ctx.arg.Map.c_str());
if (!file->is_open())
Fatal(ctx) << "cannot open " << ctx.arg.Map << ": " << strerror(errno);
return file;
}
template <typename E>
static Map<E> get_map(Context<E> &ctx) {
Map<E> map;
tbb::parallel_for_each(ctx.objs, [&](ObjectFile<E> *file) {
for (Symbol<E> *sym : file->symbols) {
if (sym->file == file && sym->input_section &&
sym->get_type() != STT_SECTION) {
assert(file == &sym->input_section->file);
typename Map<E>::accessor acc;
map.insert(acc, {sym->input_section, {}});
acc->second.push_back(sym);
}
}
});
tbb::parallel_for(map.range(), [](const typename Map<E>::range_type &range) {
for (auto it = range.begin(); it != range.end(); it++) {
std::vector<Symbol<E> *> &vec = it->second;
sort(vec, [](Symbol<E> *a, Symbol<E> *b) { return a->value < b->value; });
}
});
return map;
}
template <typename E>
void print_map(Context<E> &ctx) {
std::ostream *out = &std::cout;
std::unique_ptr<std::ofstream> file;
if (!ctx.arg.Map.empty()) {
file = open_output_file(ctx);
out = file.get();
}
// Construct a section-to-symbol map.
Map<E> map = get_map(ctx);
// Print a mapfile.
*out << " VMA Size Align Out In Symbol\n";
for (OutputChunk<E> *osec : ctx.chunks) {
*out << std::setw(16) << (u64)osec->shdr.sh_addr
<< std::setw(11) << (u64)osec->shdr.sh_size
<< std::setw(6) << (u64)osec->shdr.sh_addralign
<< " " << osec->name << "\n";
if (osec->kind != OutputChunk<E>::REGULAR)
continue;
std::span<InputSection<E> *> members = ((OutputSection<E> *)osec)->members;
std::vector<std::string> bufs(members.size());
tbb::parallel_for((i64)0, (i64)members.size(), [&](i64 i) {
InputSection<E> *mem = members[i];
std::ostringstream ss;
opt_demangle = ctx.arg.demangle;
ss << std::setw(16) << (osec->shdr.sh_addr + mem->offset)
<< std::setw(11) << (u64)mem->shdr.sh_size
<< std::setw(6) << (u64)mem->shdr.sh_addralign
<< " " << *mem << "\n";
typename Map<E>::const_accessor acc;
if (map.find(acc, mem))
for (Symbol<E> *sym : acc->second)
ss << std::setw(16) << sym->get_addr(ctx)
<< " 0 0 "
<< *sym << "\n";
bufs[i] = std::move(ss.str());
});
for (std::string &str : bufs)
*out << str;
}
}
template void print_map(Context<X86_64> &ctx);
template void print_map(Context<I386> &ctx);
+118
View File
@@ -0,0 +1,118 @@
#include "mold.h"
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
template <typename E>
MemoryMappedFile<E> *
MemoryMappedFile<E>::open(Context<E> &ctx, std::string path) {
if (path.starts_with('/') && !ctx.arg.chroot.empty())
path = ctx.arg.chroot + "/" + path_clean(path);
struct stat st;
if (stat(path.c_str(), &st) == -1)
return nullptr;
u64 mtime = (u64)st.st_mtim.tv_sec * 1000000000 + st.st_mtim.tv_nsec;
u8 *data = nullptr;
if (st.st_size == 0) {
// mmap(2) doesn't allow 0 as an argument for length parameter,
// so this case has to be handled as a special case.
static u8 dummy[1];
data = dummy;
}
MemoryMappedFile *mb = new MemoryMappedFile(path, data, st.st_size, mtime);
ctx.owning_mbs.push_back(std::unique_ptr<MemoryMappedFile>(mb));
return mb;
}
template <typename E>
MemoryMappedFile<E> *
MemoryMappedFile<E>::must_open(Context<E> &ctx, std::string path) {
if (MemoryMappedFile *mb = MemoryMappedFile::open(ctx, path))
return mb;
Fatal(ctx) << "cannot open " << path;
}
template <typename E>
u8 *MemoryMappedFile<E>::data(Context<E> &ctx) {
if (data_)
return data_;
std::lock_guard lock(mu);
if (data_)
return data_;
i64 fd = ::open(name.c_str(), O_RDONLY);
if (fd == -1)
Fatal(ctx) << name << ": cannot open: " << strerror(errno);
data_ = (u8 *)mmap(nullptr, size_, PROT_READ, MAP_PRIVATE, fd, 0);
if (data_ == MAP_FAILED)
Fatal(ctx) << name << ": mmap failed: " << strerror(errno);
close(fd);
return data_;
}
template <typename E>
MemoryMappedFile<E> *
MemoryMappedFile<E>::slice(Context<E> &ctx, std::string name, u64 start,
u64 size) {
MemoryMappedFile *mb = new MemoryMappedFile<E>(name, data_ + start, size);
ctx.owning_mbs.push_back(std::unique_ptr<MemoryMappedFile>(mb));
mb->parent = this;
return mb;
}
template <typename E>
MemoryMappedFile<E>::~MemoryMappedFile() {
if (data_ && !parent)
munmap(data_, size_);
}
template <typename E>
static bool is_text_file(Context<E> &ctx, MemoryMappedFile<E> *mb) {
u8 *data = mb->data(ctx);
return mb->size() >= 4 &&
isprint(data[0]) &&
isprint(data[1]) &&
isprint(data[2]) &&
isprint(data[3]);
}
template <typename E>
FileType get_file_type(Context<E> &ctx, MemoryMappedFile<E> *mb) {
u8 *data = mb->data(ctx);
if (mb->size() >= 20 && memcmp(data, "\177ELF", 4) == 0) {
ElfEhdr<E> &ehdr = *(ElfEhdr<E> *)data;
if (ehdr.e_type == ET_REL)
return FileType::OBJ;
if (ehdr.e_type == ET_DYN)
return FileType::DSO;
return FileType::UNKNOWN;
}
if (mb->size() >= 8 && memcmp(data, "!<arch>\n", 8) == 0)
return FileType::AR;
if (mb->size() >= 8 && memcmp(data, "!<thin>\n", 8) == 0)
return FileType::THIN_AR;
if (is_text_file(ctx, mb))
return FileType::TEXT;
if (mb->size() >= 4 && memcmp(data, "\xDE\xC0\x17\x0B", 4) == 0)
return FileType::LLVM_BITCODE;
if (mb->size() >= 4 && memcmp(data, "BC\xC0\xDE", 4) == 0)
return FileType::LLVM_BITCODE;
return FileType::UNKNOWN;
}
#define INSTANTIATE(E) \
template class MemoryMappedFile<E>; \
template FileType get_file_type(Context<E> &, MemoryMappedFile<E> *)
INSTANTIATE(X86_64);
INSTANTIATE(I386);
@@ -9,4 +9,3 @@
*.patch binary
*.dll binary
*.lib binary
*.exe binary
@@ -1,13 +1,8 @@
build
ide/vs20??/*.db
ide/vs20??/*.opendb
ide/vs20??/*.user
ide/vs20??/*.vcxproj.filters
ide/vs20??/.vs
ide/vs20??/VTune*
out/
docs/
*.zip
*.tar
*.gz
.vscode
.DS_STore
+382
View File
@@ -0,0 +1,382 @@
cmake_minimum_required(VERSION 3.0)
project(libmimalloc C CXX)
set(CMAKE_C_STANDARD 11)
set(CMAKE_CXX_STANDARD 17)
option(MI_SECURE "Use full security mitigations (like guard pages, allocation randomization, double-free mitigation, and free-list corruption detection)" OFF)
option(MI_DEBUG_FULL "Use full internal heap invariant checking in DEBUG mode (expensive)" OFF)
option(MI_PADDING "Enable padding to detect heap block overflow (used only in DEBUG mode)" ON)
option(MI_OVERRIDE "Override the standard malloc interface (e.g. define entry points for malloc() etc)" ON)
option(MI_XMALLOC "Enable abort() call on memory allocation failure by default" OFF)
option(MI_SHOW_ERRORS "Show error and warning messages by default (only enabled by default in DEBUG mode)" OFF)
option(MI_USE_CXX "Use the C++ compiler to compile the library (instead of the C compiler)" OFF)
option(MI_SEE_ASM "Generate assembly files" OFF)
option(MI_INTERPOSE "Use interpose to override standard malloc on macOS" ON)
option(MI_OSX_ZONE "Use malloc zone to override standard malloc on macOS" OFF) # enables interpose as well
option(MI_LOCAL_DYNAMIC_TLS "Use slightly slower, dlopen-compatible TLS mechanism (Unix)" OFF)
option(MI_BUILD_SHARED "Build shared library" ON)
option(MI_BUILD_STATIC "Build static library" ON)
option(MI_BUILD_OBJECT "Build object library" ON)
option(MI_BUILD_TESTS "Build test executables" ON)
option(MI_DEBUG_TSAN "Build with thread sanitizer (needs clang)" OFF)
option(MI_DEBUG_UBSAN "Build with undefined-behavior sanitizer (needs clang++)" OFF)
option(MI_CHECK_FULL "Use full internal invariant checking in DEBUG mode (deprecated, use MI_DEBUG_FULL instead)" OFF)
option(MI_INSTALL_TOPLEVEL "Install directly into $CMAKE_INSTALL_PREFIX instead of PREFIX/lib/mimalloc-version" OFF)
include("cmake/mimalloc-config-version.cmake")
set(mi_sources
src/stats.c
src/random.c
src/os.c
src/bitmap.c
src/arena.c
src/region.c
src/segment.c
src/page.c
src/alloc.c
src/alloc-aligned.c
src/alloc-posix.c
src/heap.c
src/options.c
src/init.c)
# -----------------------------------------------------------------------------
# Converience: set default build type depending on the build directory
# -----------------------------------------------------------------------------
if (NOT CMAKE_BUILD_TYPE)
if ("${CMAKE_BINARY_DIR}" MATCHES ".*(D|d)ebug$" OR MI_DEBUG_FULL)
message(STATUS "No build type selected, default to: Debug")
set(CMAKE_BUILD_TYPE "Debug")
else()
message(STATUS "No build type selected, default to: Release")
set(CMAKE_BUILD_TYPE "Release")
endif()
endif()
if("${CMAKE_BINARY_DIR}" MATCHES ".*(S|s)ecure$")
message(STATUS "Default to secure build")
set(MI_SECURE "ON")
endif()
# -----------------------------------------------------------------------------
# Process options
# -----------------------------------------------------------------------------
if(CMAKE_C_COMPILER_ID MATCHES "MSVC|Intel")
set(MI_USE_CXX "ON")
endif()
if(MI_OVERRIDE)
message(STATUS "Override standard malloc (MI_OVERRIDE=ON)")
if(APPLE)
if(MI_OSX_ZONE)
# use zone's on macOS
message(STATUS " Use malloc zone to override malloc (MI_OSX_ZONE=ON)")
list(APPEND mi_sources src/alloc-override-osx.c)
list(APPEND mi_defines MI_OSX_ZONE=1)
if(NOT MI_INTERPOSE)
message(STATUS " (enabling INTERPOSE as well since zone's require this)")
set(MI_INTERPOSE "ON")
endif()
endif()
if(MI_INTERPOSE)
# use interpose on macOS
message(STATUS " Use interpose to override malloc (MI_INTERPOSE=ON)")
list(APPEND mi_defines MI_INTERPOSE)
endif()
endif()
endif()
if(MI_SECURE)
message(STATUS "Set full secure build (MI_SECURE=ON)")
list(APPEND mi_defines MI_SECURE=4)
endif()
if(MI_SEE_ASM)
message(STATUS "Generate assembly listings (MI_SEE_ASM=ON)")
list(APPEND mi_cflags -save-temps)
endif()
if(MI_CHECK_FULL)
message(STATUS "The MI_CHECK_FULL option is deprecated, use MI_DEBUG_FULL instead")
set(MI_DEBUG_FULL "ON")
endif()
if(MI_DEBUG_FULL)
message(STATUS "Set debug level to full internal invariant checking (MI_DEBUG_FULL=ON)")
list(APPEND mi_defines MI_DEBUG=3) # full invariant checking
endif()
if(NOT MI_PADDING)
message(STATUS "Disable padding of heap blocks in debug mode (MI_PADDING=OFF)")
list(APPEND mi_defines MI_PADDING=0)
endif()
if(MI_XMALLOC)
message(STATUS "Enable abort() calls on memory allocation failure (MI_XMALLOC=ON)")
list(APPEND mi_defines MI_XMALLOC=1)
endif()
if(MI_SHOW_ERRORS)
message(STATUS "Enable printing of error and warning messages by default (MI_SHOW_ERRORS=ON)")
list(APPEND mi_defines MI_SHOW_ERRORS=1)
endif()
if(MI_DEBUG_TSAN)
if(CMAKE_C_COMPILER_ID MATCHES "Clang")
message(STATUS "Build with thread sanitizer (MI_DEBUG_TSAN=ON)")
list(APPEND mi_defines MI_TSAN=1)
list(APPEND mi_cflags -fsanitize=thread -g -O1)
list(APPEND CMAKE_EXE_LINKER_FLAGS -fsanitize=thread)
else()
message(WARNING "Can only use thread sanitizer with clang (MI_DEBUG_TSAN=ON but ignored)")
endif()
endif()
if(MI_DEBUG_UBSAN)
if(CMAKE_BUILD_TYPE MATCHES "Debug")
if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
message(STATUS "Build with undefined-behavior sanitizer (MI_DEBUG_UBSAN=ON)")
list(APPEND mi_cflags -fsanitize=undefined -g)
list(APPEND CMAKE_EXE_LINKER_FLAGS -fsanitize=undefined)
if (NOT MI_USE_CXX)
message(STATUS "(switch to use C++ due to MI_DEBUG_UBSAN)")
set(MI_USE_CXX "ON")
endif()
else()
message(WARNING "Can only use undefined-behavior sanitizer with clang++ (MI_DEBUG_UBSAN=ON but ignored)")
endif()
else()
message(WARNING "Can only use thread sanitizer with a debug build (CMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE})")
endif()
endif()
if(MI_USE_CXX)
message(STATUS "Use the C++ compiler to compile (MI_USE_CXX=ON)")
set_source_files_properties(${mi_sources} PROPERTIES LANGUAGE CXX )
set_source_files_properties(src/static.c test/test-api.c test/test-stress PROPERTIES LANGUAGE CXX )
if(CMAKE_CXX_COMPILER_ID MATCHES "AppleClang|Clang")
list(APPEND mi_cflags -Wno-deprecated)
endif()
if(CMAKE_CXX_COMPILER_ID MATCHES "Intel")
list(APPEND mi_cflags -Kc++)
endif()
endif()
# Compiler flags
if(CMAKE_C_COMPILER_ID MATCHES "AppleClang|Clang|GNU")
list(APPEND mi_cflags -Wall -Wextra -Wno-unknown-pragmas -fvisibility=hidden)
if(CMAKE_C_COMPILER_ID MATCHES "GNU")
list(APPEND mi_cflags -Wno-invalid-memory-model)
endif()
endif()
if(CMAKE_C_COMPILER_ID MATCHES "Intel")
list(APPEND mi_cflags -Wall -fvisibility=hidden)
endif()
if(CMAKE_C_COMPILER_ID MATCHES "AppleClang|Clang|GNU|Intel" AND NOT CMAKE_SYSTEM_NAME MATCHES "Haiku")
if(MI_LOCAL_DYNAMIC_TLS)
list(APPEND mi_cflags -ftls-model=local-dynamic)
else()
list(APPEND mi_cflags -ftls-model=initial-exec)
endif()
endif()
if (MSVC AND MSVC_VERSION GREATER_EQUAL 1914)
list(APPEND mi_cflags /Zc:__cplusplus)
endif()
# extra needed libraries
if(WIN32)
list(APPEND mi_libraries psapi shell32 user32 advapi32 bcrypt)
else()
if(NOT ${CMAKE_C_COMPILER} MATCHES "android")
list(APPEND mi_libraries pthread)
find_library(LIBRT rt)
if(LIBRT)
list(APPEND mi_libraries ${LIBRT})
endif()
endif()
endif()
# -----------------------------------------------------------------------------
# Install and output names
# -----------------------------------------------------------------------------
if (MI_INSTALL_TOPLEVEL)
set(mi_install_dir "${CMAKE_INSTALL_PREFIX}")
else()
set(mi_install_dir "${CMAKE_INSTALL_PREFIX}/lib/mimalloc-${mi_version}")
endif()
if(MI_SECURE)
set(mi_basename "mimalloc-secure")
else()
set(mi_basename "mimalloc")
endif()
string(TOLOWER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE_LC)
if(NOT(CMAKE_BUILD_TYPE_LC MATCHES "^(release|relwithdebinfo|minsizerel)$"))
set(mi_basename "${mi_basename}-${CMAKE_BUILD_TYPE_LC}") #append build type (e.g. -debug) if not a release version
endif()
if(MI_BUILD_SHARED)
list(APPEND mi_build_targets "shared")
endif()
if(MI_BUILD_STATIC)
list(APPEND mi_build_targets "static")
endif()
if(MI_BUILD_OBJECT)
list(APPEND mi_build_targets "object")
endif()
if(MI_BUILD_TESTS)
list(APPEND mi_build_targets "tests")
endif()
message(STATUS "")
message(STATUS "Library base name: ${mi_basename}")
message(STATUS "Build type : ${CMAKE_BUILD_TYPE_LC}")
if(MI_USE_CXX)
message(STATUS "Compiler : ${CMAKE_CXX_COMPILER}")
else()
message(STATUS "Compiler : ${CMAKE_C_COMPILER}")
endif()
message(STATUS "Install directory: ${mi_install_dir}")
message(STATUS "Build targets : ${mi_build_targets}")
message(STATUS "")
# -----------------------------------------------------------------------------
# Main targets
# -----------------------------------------------------------------------------
# shared library
if(MI_BUILD_SHARED)
add_library(mimalloc SHARED ${mi_sources})
set_target_properties(mimalloc PROPERTIES VERSION ${mi_version} OUTPUT_NAME ${mi_basename} )
target_compile_definitions(mimalloc PRIVATE ${mi_defines} MI_SHARED_LIB MI_SHARED_LIB_EXPORT)
target_compile_options(mimalloc PRIVATE ${mi_cflags})
target_link_libraries(mimalloc PUBLIC ${mi_libraries})
target_include_directories(mimalloc PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
$<INSTALL_INTERFACE:${mi_install_dir}/include>
)
if(WIN32)
# On windows copy the mimalloc redirection dll too.
target_link_libraries(mimalloc PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/bin/mimalloc-redirect.lib)
add_custom_command(TARGET mimalloc POST_BUILD
COMMAND "${CMAKE_COMMAND}" -E copy "${CMAKE_CURRENT_SOURCE_DIR}/bin/mimalloc-redirect.dll" $<TARGET_FILE_DIR:mimalloc>
COMMENT "Copy mimalloc-redirect.dll to output directory")
endif()
if (MI_INSTALL_TOPLEVEL MATCHES "ON")
install(TARGETS mimalloc EXPORT mimalloc LIBRARY
RUNTIME DESTINATION bin
LIBRARY DESTINATION lib
ARCHIVE DESTINATION lib)
else()
install(TARGETS mimalloc EXPORT mimalloc DESTINATION ${mi_install_dir} LIBRARY)
endif()
install(EXPORT mimalloc DESTINATION ${mi_install_dir}/cmake)
endif()
# static library
if (MI_BUILD_STATIC)
add_library(mimalloc-static STATIC ${mi_sources})
set_property(TARGET mimalloc-static PROPERTY POSITION_INDEPENDENT_CODE ON)
target_compile_definitions(mimalloc-static PRIVATE ${mi_defines} MI_STATIC_LIB)
target_compile_options(mimalloc-static PRIVATE ${mi_cflags})
target_link_libraries(mimalloc-static PUBLIC ${mi_libraries})
target_include_directories(mimalloc-static PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
$<INSTALL_INTERFACE:${mi_install_dir}/include>
)
if(WIN32)
# When building both static and shared libraries on Windows, a static library should use a
# different output name to avoid the conflict with the import library of a shared one.
string(REPLACE "mimalloc" "mimalloc-static" mi_output_name ${mi_basename})
set_target_properties(mimalloc-static PROPERTIES OUTPUT_NAME ${mi_output_name})
else()
set_target_properties(mimalloc-static PROPERTIES OUTPUT_NAME ${mi_basename})
endif()
install(TARGETS mimalloc-static EXPORT mimalloc DESTINATION ${mi_install_dir})
endif()
# install include files
install(FILES include/mimalloc.h DESTINATION ${mi_install_dir}/include)
install(FILES include/mimalloc-override.h DESTINATION ${mi_install_dir}/include)
install(FILES include/mimalloc-new-delete.h DESTINATION ${mi_install_dir}/include)
install(FILES cmake/mimalloc-config.cmake DESTINATION ${mi_install_dir}/cmake)
install(FILES cmake/mimalloc-config-version.cmake DESTINATION ${mi_install_dir}/cmake)
if(NOT WIN32 AND MI_BUILD_SHARED AND NOT MI_INSTALL_TOPLEVEL)
# install a symlink in the /usr/local/lib to the versioned library
set(mi_symlink "${CMAKE_SHARED_MODULE_PREFIX}${mi_basename}${CMAKE_SHARED_LIBRARY_SUFFIX}")
set(mi_soname "mimalloc-${mi_version}/${mi_symlink}.${mi_version}")
install(CODE "execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${mi_soname} ${mi_symlink} WORKING_DIRECTORY ${mi_install_dir}/..)")
install(CODE "MESSAGE(\"-- Symbolic link: ${CMAKE_INSTALL_PREFIX}/lib/${mi_symlink} -> ${mi_soname}\")")
endif()
# single object file for more predictable static overriding
if (MI_BUILD_OBJECT)
add_library(mimalloc-obj OBJECT src/static.c)
set_property(TARGET mimalloc-obj PROPERTY POSITION_INDEPENDENT_CODE ON)
target_compile_definitions(mimalloc-obj PRIVATE ${mi_defines})
target_compile_options(mimalloc-obj PRIVATE ${mi_cflags})
target_include_directories(mimalloc-obj PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
$<INSTALL_INTERFACE:${mi_install_dir}/include>
)
# the following seems to lead to cmake warnings/errors on some systems, disable for now :-(
# install(TARGETS mimalloc-obj EXPORT mimalloc DESTINATION ${mi_install_dir})
# the FILES expression can also be: $<TARGET_OBJECTS:mimalloc-obj>
# but that fails cmake versions less than 3.10 so we leave it as is for now
install(FILES ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/mimalloc-obj.dir/src/static.c${CMAKE_C_OUTPUT_EXTENSION}
DESTINATION ${mi_install_dir}
RENAME ${mi_basename}${CMAKE_C_OUTPUT_EXTENSION} )
endif()
# -----------------------------------------------------------------------------
# API surface testing
# -----------------------------------------------------------------------------
if (MI_BUILD_TESTS)
add_executable(mimalloc-test-api test/test-api.c)
target_compile_definitions(mimalloc-test-api PRIVATE ${mi_defines})
target_compile_options(mimalloc-test-api PRIVATE ${mi_cflags})
target_include_directories(mimalloc-test-api PRIVATE include)
target_link_libraries(mimalloc-test-api PRIVATE mimalloc-static ${mi_libraries})
add_executable(mimalloc-test-stress test/test-stress.c)
target_compile_definitions(mimalloc-test-stress PRIVATE ${mi_defines})
target_compile_options(mimalloc-test-stress PRIVATE ${mi_cflags})
target_include_directories(mimalloc-test-stress PRIVATE include)
target_link_libraries(mimalloc-test-stress PRIVATE mimalloc ${mi_libraries})
enable_testing()
add_test(test_api, mimalloc-test-api)
add_test(test_stress, mimalloc-test-stress)
endif()
# -----------------------------------------------------------------------------
# Set override properties
# -----------------------------------------------------------------------------
if (MI_OVERRIDE)
if (MI_BUILD_SHARED)
target_compile_definitions(mimalloc PRIVATE MI_MALLOC_OVERRIDE)
endif()
if(NOT WIN32)
# It is only possible to override malloc on Windows when building as a DLL.
if (MI_BUILD_STATIC)
target_compile_definitions(mimalloc-static PRIVATE MI_MALLOC_OVERRIDE)
endif()
if (MI_BUILD_OBJECT)
target_compile_definitions(mimalloc-obj PRIVATE MI_MALLOC_OVERRIDE)
endif()
endif()
endif()
@@ -1,6 +1,6 @@
MIT License
Copyright (c) 2018-2025 Microsoft Corporation, Daan Leijen
Copyright (c) 2019 Microsoft Corporation, Daan Leijen
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
+174
View File
@@ -0,0 +1,174 @@
# Starter pipeline
# Start with a minimal pipeline that you can customize to build and deploy your code.
# Add steps that build, run tests, deploy, and more:
# https://aka.ms/yaml
trigger:
branches:
include:
- master
- dev
- dev-slice
tags:
include:
- v*
jobs:
- job:
displayName: Windows
pool:
vmImage:
windows-2019
strategy:
matrix:
Debug:
BuildType: debug
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Debug -DMI_DEBUG_FULL=ON
MSBuildConfiguration: Debug
Release:
BuildType: release
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Release
MSBuildConfiguration: Release
Secure:
BuildType: secure
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Release -DMI_SECURE=ON
MSBuildConfiguration: Release
steps:
- task: CMake@1
inputs:
workingDirectory: $(BuildType)
cmakeArgs: .. $(cmakeExtraArgs)
- task: MSBuild@1
inputs:
solution: $(BuildType)/libmimalloc.sln
configuration: '$(MSBuildConfiguration)'
msbuildArguments: -m
- script: ctest --verbose --timeout 120
workingDirectory: $(BuildType)
displayName: CTest
#- script: $(BuildType)\$(BuildType)\mimalloc-test-stress
# displayName: TestStress
#- upload: $(Build.SourcesDirectory)/$(BuildType)
# artifact: mimalloc-windows-$(BuildType)
- job:
displayName: Linux
pool:
vmImage:
ubuntu-18.04
strategy:
matrix:
Debug:
CC: gcc
CXX: g++
BuildType: debug
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Debug -DMI_DEBUG_FULL=ON
Release:
CC: gcc
CXX: g++
BuildType: release
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Release
Secure:
CC: gcc
CXX: g++
BuildType: secure
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Release -DMI_SECURE=ON
Debug++:
CC: gcc
CXX: g++
BuildType: debug-cxx
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Debug -DMI_DEBUG_FULL=ON -DMI_USE_CXX=ON
Debug Clang:
CC: clang
CXX: clang++
BuildType: debug-clang
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Debug -DMI_DEBUG_FULL=ON
Release Clang:
CC: clang
CXX: clang++
BuildType: release-clang
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Release
Secure Clang:
CC: clang
CXX: clang++
BuildType: secure-clang
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Release -DMI_SECURE=ON
Debug++ Clang:
CC: clang
CXX: clang++
BuildType: debug-clang-cxx
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Debug -DMI_DEBUG_FULL=ON -DMI_USE_CXX=ON
steps:
- task: CMake@1
inputs:
workingDirectory: $(BuildType)
cmakeArgs: .. $(cmakeExtraArgs)
- script: make -j$(nproc) -C $(BuildType)
displayName: Make
- script: ctest --verbose --timeout 120
workingDirectory: $(BuildType)
displayName: CTest
# - upload: $(Build.SourcesDirectory)/$(BuildType)
# artifact: mimalloc-ubuntu-$(BuildType)
- job:
displayName: macOS
pool:
vmImage:
macOS-10.14
strategy:
matrix:
Debug:
BuildType: debug
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Debug -DMI_DEBUG_FULL=ON
Release:
BuildType: release
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Release
Secure:
BuildType: secure
cmakeExtraArgs: -DCMAKE_BUILD_TYPE=Release -DMI_SECURE=ON
steps:
- task: CMake@1
inputs:
workingDirectory: $(BuildType)
cmakeArgs: .. $(cmakeExtraArgs)
- script: make -j$(sysctl -n hw.ncpu) -C $(BuildType)
displayName: Make
- script: ctest --verbose --timeout 120
workingDirectory: $(BuildType)
displayName: CTest
# - upload: $(Build.SourcesDirectory)/$(BuildType)
# artifact: mimalloc-macos-$(BuildType)
# - job:
# displayName: Windows-2017
# pool:
# vmImage:
# vs2017-win2016
# strategy:
# matrix:
# Debug:
# BuildType: debug
# cmakeExtraArgs: -A x64 -DCMAKE_BUILD_TYPE=Debug -DMI_DEBUG_FULL=ON
# MSBuildConfiguration: Debug
# Release:
# BuildType: release
# cmakeExtraArgs: -A x64 -DCMAKE_BUILD_TYPE=Release
# MSBuildConfiguration: Release
# Secure:
# BuildType: secure
# cmakeExtraArgs: -A x64 -DCMAKE_BUILD_TYPE=Release -DMI_SECURE=ON
# MSBuildConfiguration: Release
# steps:
# - task: CMake@1
# inputs:
# workingDirectory: $(BuildType)
# cmakeArgs: .. $(cmakeExtraArgs)
# - task: MSBuild@1
# inputs:
# solution: $(BuildType)/libmimalloc.sln
# configuration: '$(MSBuildConfiguration)'
# - script: |
# cd $(BuildType)
# ctest --verbose --timeout 120
# displayName: CTest
Binary file not shown.
Binary file not shown.
@@ -1,6 +1,5 @@
set(mi_version_major 2)
set(mi_version_minor 2)
set(mi_version_patch 2)
set(mi_version_major 1)
set(mi_version_minor 7)
set(mi_version ${mi_version_major}.${mi_version_minor})
set(PACKAGE_VERSION ${mi_version})
+2
View File
@@ -0,0 +1,2 @@
include(${CMAKE_CURRENT_LIST_DIR}/mimalloc.cmake)
get_filename_component(MIMALLOC_TARGET_DIR "${CMAKE_CURRENT_LIST_DIR}" PATH)
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@@ -1,4 +1,4 @@
# Doxyfile 1.8.13
# Doxyfile 1.8.15
# This file describes the settings to be used by the documentation system
# doxygen (www.doxygen.org) for a project.
@@ -17,11 +17,11 @@
# Project related configuration options
#---------------------------------------------------------------------------
# This tag specifies the encoding used for all characters in the config file
# that follow. The default is UTF-8 which is also the encoding used for all text
# before the first occurrence of this tag. Doxygen uses libiconv (or the iconv
# built into libc) for the transcoding. See http://www.gnu.org/software/libiconv
# for the list of possible encodings.
# This tag specifies the encoding used for all characters in the configuration
# file that follow. The default is UTF-8 which is also the encoding used for all
# text before the first occurrence of this tag. Doxygen uses libiconv (or the
# iconv built into libc) for the transcoding. See
# https://www.gnu.org/software/libiconv/ for the list of possible encodings.
# The default value is: UTF-8.
DOXYFILE_ENCODING = UTF-8
@@ -32,13 +32,13 @@ DOXYFILE_ENCODING = UTF-8
# title of most generated pages and in a few other places.
# The default value is: My Project.
PROJECT_NAME = "oneTBB Test Specification"
PROJECT_NAME = mi-malloc
# The PROJECT_NUMBER tag can be used to enter a project or revision number. This
# could be handy for archiving the generated documentation or if some version
# control system is used.
PROJECT_NUMBER =
PROJECT_NUMBER = 1.6
# Using the PROJECT_BRIEF tag one can provide an optional one line description
# for a project that appears at the top of each page and should give viewer a
@@ -51,14 +51,14 @@ PROJECT_BRIEF =
# pixels and the maximum width should not exceed 200 pixels. Doxygen will copy
# the logo to the output directory.
PROJECT_LOGO =
PROJECT_LOGO = mimalloc-logo.svg
# The OUTPUT_DIRECTORY tag is used to specify the (relative or absolute) path
# into which the generated documentation will be written. If a relative path is
# entered, it will be relative to the location where doxygen was started. If
# left blank the current directory will be used.
OUTPUT_DIRECTORY =
OUTPUT_DIRECTORY = ..
# If the CREATE_SUBDIRS tag is set to YES then doxygen will create 4096 sub-
# directories (in 2 levels) under the output directory of each output format and
@@ -93,6 +93,14 @@ ALLOW_UNICODE_NAMES = NO
OUTPUT_LANGUAGE = English
# The OUTPUT_TEXT_DIRECTION tag is used to specify the direction in which all
# documentation generated by doxygen is written. Doxygen will use this
# information to generate all generated output in the proper direction.
# Possible values are: None, LTR, RTL and Context.
# The default value is: None.
OUTPUT_TEXT_DIRECTION = None
# If the BRIEF_MEMBER_DESC tag is set to YES, doxygen will include brief member
# descriptions after the members that are listed in the file and class
# documentation (similar to Javadoc). Set to NO to disable this.
@@ -187,7 +195,7 @@ SHORT_NAMES = NO
# description.)
# The default value is: NO.
JAVADOC_AUTOBRIEF = NO
JAVADOC_AUTOBRIEF = YES
# If the QT_AUTOBRIEF tag is set to YES then doxygen will interpret the first
# line (until the first dot) of a Qt-style comment as the brief description. If
@@ -226,7 +234,7 @@ SEPARATE_MEMBER_PAGES = NO
# uses this value to replace tabs by spaces in code fragments.
# Minimum value: 1, maximum value: 16, default value: 4.
TAB_SIZE = 4
TAB_SIZE = 2
# This tag can be used to specify a number of aliases that act as commands in
# the documentation. An alias has the form:
@@ -236,7 +244,12 @@ TAB_SIZE = 4
# will allow you to put the command \sideeffect (or @sideeffect) in the
# documentation, which will result in a user-defined paragraph with heading
# "Side Effects:". You can put \n's in the value part of an alias to insert
# newlines.
# newlines (in the resulting output). You can put ^^ in the value part of an
# alias to insert a newline as if a physical newline was in the original file.
# When you need a literal { or } or , in the value part of an alias you have to
# escape them by means of a backslash (\), this can lead to conflicts with the
# commands \{ and \} for these it is advised to use the version @{ and @} or use
# a double escape (\\{ and \\})
ALIASES =
@@ -252,7 +265,7 @@ TCL_SUBST =
# members will be omitted, etc.
# The default value is: NO.
OPTIMIZE_OUTPUT_FOR_C = NO
OPTIMIZE_OUTPUT_FOR_C = YES
# Set the OPTIMIZE_OUTPUT_JAVA tag to YES if your project consists of Java or
# Python sources only. Doxygen will then generate output that is more tailored
@@ -274,17 +287,26 @@ OPTIMIZE_FOR_FORTRAN = NO
OPTIMIZE_OUTPUT_VHDL = NO
# Set the OPTIMIZE_OUTPUT_SLICE tag to YES if your project consists of Slice
# sources only. Doxygen will then generate output that is more tailored for that
# language. For instance, namespaces will be presented as modules, types will be
# separated into more groups, etc.
# The default value is: NO.
OPTIMIZE_OUTPUT_SLICE = NO
# Doxygen selects the parser to use depending on the extension of the files it
# parses. With this tag you can assign which parser to use for a given
# extension. Doxygen has a built-in mapping, but you can override or extend it
# using this tag. The format is ext=language, where ext is a file extension, and
# language is one of the parsers supported by doxygen: IDL, Java, Javascript,
# C#, C, C++, D, PHP, Objective-C, Python, Fortran (fixed format Fortran:
# FortranFixed, free formatted Fortran: FortranFree, unknown formatted Fortran:
# Fortran. In the later case the parser tries to guess whether the code is fixed
# or free formatted code, this is the default for Fortran type files), VHDL. For
# instance to make doxygen treat .inc files as Fortran files (default is PHP),
# and .f files as C (default is Fortran), use: inc=Fortran f=C.
# Csharp (C#), C, C++, D, PHP, md (Markdown), Objective-C, Python, Slice,
# Fortran (fixed format Fortran: FortranFixed, free formatted Fortran:
# FortranFree, unknown formatted Fortran: Fortran. In the later case the parser
# tries to guess whether the code is fixed or free formatted code, this is the
# default for Fortran type files), VHDL, tcl. For instance to make doxygen treat
# .inc files as Fortran files (default is PHP), and .f files as C (default is
# Fortran), use: inc=Fortran f=C.
#
# Note: For files without extension you can use no_extension as a placeholder.
#
@@ -295,7 +317,7 @@ EXTENSION_MAPPING =
# If the MARKDOWN_SUPPORT tag is enabled then doxygen pre-processes all comments
# according to the Markdown format, which allows for more readable
# documentation. See http://daringfireball.net/projects/markdown/ for details.
# documentation. See https://daringfireball.net/projects/markdown/ for details.
# The output of markdown processing is further processed by doxygen, so you can
# mix doxygen, HTML, and XML commands with Markdown formatting. Disable only in
# case of backward compatibilities issues.
@@ -337,7 +359,7 @@ BUILTIN_STL_SUPPORT = NO
CPP_CLI_SUPPORT = NO
# Set the SIP_SUPPORT tag to YES if your project consists of sip (see:
# http://www.riverbankcomputing.co.uk/software/sip/intro) sources only. Doxygen
# https://www.riverbankcomputing.com/software/sip/intro) sources only. Doxygen
# will parse them like normal C++ but will assume all classes use public instead
# of private inheritance when no explicit protection keyword is present.
# The default value is: NO.
@@ -397,7 +419,7 @@ INLINE_GROUPED_CLASSES = NO
# Man pages) or section (for LaTeX and RTF).
# The default value is: NO.
INLINE_SIMPLE_STRUCTS = NO
INLINE_SIMPLE_STRUCTS = YES
# When TYPEDEF_HIDES_STRUCT tag is enabled, a typedef of a struct, union, or
# enum is documented as struct, union, or enum with the name of the typedef. So
@@ -408,7 +430,7 @@ INLINE_SIMPLE_STRUCTS = NO
# types are typedef'ed and only the typedef is referenced, never the tag name.
# The default value is: NO.
TYPEDEF_HIDES_STRUCT = NO
TYPEDEF_HIDES_STRUCT = YES
# The size of the symbol lookup cache can be set using LOOKUP_CACHE_SIZE. This
# cache is used to resolve symbols given their name and scope. Since this can be
@@ -435,7 +457,7 @@ LOOKUP_CACHE_SIZE = 0
# normally produced when WARNINGS is set to YES.
# The default value is: NO.
EXTRACT_ALL = NO
EXTRACT_ALL = YES
# If the EXTRACT_PRIVATE tag is set to YES, all private members of a class will
# be included in the documentation.
@@ -524,7 +546,7 @@ INTERNAL_DOCS = NO
# and Mac users are advised to set this option to NO.
# The default value is: system dependent.
CASE_SENSE_NAMES = YES
CASE_SENSE_NAMES = NO
# If the HIDE_SCOPE_NAMES tag is set to NO then doxygen will show members with
# their full class and namespace scopes in the documentation. If set to YES, the
@@ -659,28 +681,28 @@ ENABLED_SECTIONS =
# documentation regardless of this setting.
# Minimum value: 0, maximum value: 10000, default value: 30.
MAX_INITIALIZER_LINES = 30
MAX_INITIALIZER_LINES = 0
# Set the SHOW_USED_FILES tag to NO to disable the list of files generated at
# the bottom of the documentation of classes and structs. If set to YES, the
# list will mention the files that were used to generate the documentation.
# The default value is: YES.
SHOW_USED_FILES = YES
SHOW_USED_FILES = NO
# Set the SHOW_FILES tag to NO to disable the generation of the Files page. This
# will remove the Files entry from the Quick Index and from the Folder Tree View
# (if specified).
# The default value is: YES.
SHOW_FILES = YES
SHOW_FILES = NO
# Set the SHOW_NAMESPACES tag to NO to disable the generation of the Namespaces
# page. This will remove the Namespaces entry from the Quick Index and from the
# Folder Tree View (if specified).
# The default value is: YES.
SHOW_NAMESPACES = NO
SHOW_NAMESPACES = YES
# The FILE_VERSION_FILTER tag can be used to specify a program or script that
# doxygen should invoke to get the current version for each file (typically from
@@ -703,12 +725,12 @@ FILE_VERSION_FILTER =
# DoxygenLayout.xml, doxygen will parse it automatically even if the LAYOUT_FILE
# tag is left empty.
LAYOUT_FILE = @CMAKE_CURRENT_SOURCE_DIR@/doc/DoxygenLayout.xml
LAYOUT_FILE =
# The CITE_BIB_FILES tag can be used to specify one or more bib files containing
# the reference definitions. This must be a list of .bib files. The .bib
# extension is automatically appended if omitted. This requires the bibtex tool
# to be installed. See also http://en.wikipedia.org/wiki/BibTeX for more info.
# to be installed. See also https://en.wikipedia.org/wiki/BibTeX for more info.
# For LaTeX the style of the bibliography can be controlled using
# LATEX_BIB_STYLE. To use this feature you need bibtex and perl available in the
# search path. See also \cite for info how to create references.
@@ -753,7 +775,8 @@ WARN_IF_DOC_ERROR = YES
# This WARN_NO_PARAMDOC option can be enabled to get warnings for functions that
# are documented, but have no documentation for their parameters or return
# value. If set to NO, doxygen will only warn about wrong or incomplete
# parameter documentation, but not about the absence of documentation.
# parameter documentation, but not about the absence of documentation. If
# EXTRACT_ALL is set to YES then this flag will automatically be disabled.
# The default value is: NO.
WARN_NO_PARAMDOC = NO
@@ -790,13 +813,12 @@ WARN_LOGFILE =
# spaces. See also FILE_PATTERNS and EXTENSION_MAPPING
# Note: If this tag is empty the current directory is searched.
INPUT = @CMAKE_CURRENT_SOURCE_DIR@/test \
@CMAKE_CURRENT_SOURCE_DIR@/doc
INPUT = mimalloc-doc.h
# This tag can be used to specify the character encoding of the source files
# that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
# libiconv (or the iconv built into libc) for the transcoding. See the libiconv
# documentation (see: http://www.gnu.org/software/libiconv) for the list of
# documentation (see: https://www.gnu.org/software/libiconv/) for the list of
# possible encodings.
# The default value is: UTF-8.
@@ -814,7 +836,7 @@ INPUT_ENCODING = UTF-8
# *.c++, *.java, *.ii, *.ixx, *.ipp, *.i++, *.inl, *.idl, *.ddl, *.odl, *.h,
# *.hh, *.hxx, *.hpp, *.h++, *.cs, *.d, *.php, *.php4, *.php5, *.phtml, *.inc,
# *.m, *.markdown, *.md, *.mm, *.dox, *.py, *.pyw, *.f90, *.f95, *.f03, *.f08,
# *.f, *.for, *.tcl, *.vhd, *.vhdl, *.ucf and *.qsf.
# *.f, *.for, *.tcl, *.vhd, *.vhdl, *.ucf, *.qsf and *.ice.
FILE_PATTERNS = *.c \
*.cc \
@@ -865,7 +887,7 @@ FILE_PATTERNS = *.c \
# be searched for input files as well.
# The default value is: NO.
RECURSIVE = YES
RECURSIVE = NO
# The EXCLUDE tag can be used to specify files and/or directories that should be
# excluded from the INPUT source files. This way you can easily exclude a
@@ -890,7 +912,7 @@ EXCLUDE_SYMLINKS = NO
# Note that the wildcards are matched against the file with absolute path, so to
# exclude all test directories for example use the pattern */test/*
EXCLUDE_PATTERNS = */common/*
EXCLUDE_PATTERNS =
# The EXCLUDE_SYMBOLS tag can be used to specify one or more symbol names
# (namespaces, classes, functions, etc.) that should be excluded from the
@@ -996,7 +1018,7 @@ USE_MDFILE_AS_MAINPAGE =
# also VERBATIM_HEADERS is set to NO.
# The default value is: NO.
SOURCE_BROWSER = YES
SOURCE_BROWSER = NO
# Setting the INLINE_SOURCES tag to YES will include the body of functions,
# classes and enums directly into the documentation.
@@ -1009,10 +1031,10 @@ INLINE_SOURCES = NO
# Fortran comments will always remain visible.
# The default value is: YES.
STRIP_CODE_COMMENTS = NO
STRIP_CODE_COMMENTS = YES
# If the REFERENCED_BY_RELATION tag is set to YES then for each documented
# function all documented functions referencing it will be listed.
# entity all documented functions referencing it will be listed.
# The default value is: NO.
REFERENCED_BY_RELATION = NO
@@ -1044,12 +1066,12 @@ SOURCE_TOOLTIPS = YES
# If the USE_HTAGS tag is set to YES then the references to source code will
# point to the HTML generated by the htags(1) tool instead of doxygen built-in
# source browser. The htags tool is part of GNU's global source tagging system
# (see http://www.gnu.org/software/global/global.html). You will need version
# (see https://www.gnu.org/software/global/global.html). You will need version
# 4.8.6 or higher.
#
# To use it do the following:
# - Install the latest version of global
# - Enable SOURCE_BROWSER and USE_HTAGS in the config file
# - Enable SOURCE_BROWSER and USE_HTAGS in the configuration file
# - Make sure the INPUT points to the root of the source tree
# - Run doxygen as normal
#
@@ -1077,7 +1099,7 @@ VERBATIM_HEADERS = YES
# rich C++ code for which doxygen's built-in parser lacks the necessary type
# information.
# Note: The availability of this option depends on whether or not doxygen was
# generated with the -Duse-libclang=ON option for CMake.
# generated with the -Duse_libclang=ON option for CMake.
# The default value is: NO.
CLANG_ASSISTED_PARSING = NO
@@ -1090,6 +1112,16 @@ CLANG_ASSISTED_PARSING = NO
CLANG_OPTIONS =
# If clang assisted parsing is enabled you can provide the clang parser with the
# path to the compilation database (see:
# http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html) used when the files
# were built. This is equivalent to specifying the "-p" option to a clang tool,
# such as clang-check. These options will then be passed to the parser.
# Note: The availability of this option depends on whether or not doxygen was
# generated with the -Duse_libclang=ON option for CMake.
CLANG_DATABASE_PATH =
#---------------------------------------------------------------------------
# Configuration options related to the alphabetical class index
#---------------------------------------------------------------------------
@@ -1131,7 +1163,7 @@ GENERATE_HTML = YES
# The default directory is: html.
# This tag requires that the tag GENERATE_HTML is set to YES.
HTML_OUTPUT = test_spec
HTML_OUTPUT = docs
# The HTML_FILE_EXTENSION tag can be used to specify the file extension for each
# generated HTML page (for example: .htm, .php, .asp).
@@ -1193,7 +1225,7 @@ HTML_STYLESHEET =
# list). For an example see the documentation.
# This tag requires that the tag GENERATE_HTML is set to YES.
HTML_EXTRA_STYLESHEET =
HTML_EXTRA_STYLESHEET = mimalloc-doxygen.css
# The HTML_EXTRA_FILES tag can be used to specify one or more extra images or
# other source files which should be copied to the HTML output directory. Note
@@ -1208,13 +1240,13 @@ HTML_EXTRA_FILES =
# The HTML_COLORSTYLE_HUE tag controls the color of the HTML output. Doxygen
# will adjust the colors in the style sheet and background images according to
# this color. Hue is specified as an angle on a colorwheel, see
# http://en.wikipedia.org/wiki/Hue for more information. For instance the value
# https://en.wikipedia.org/wiki/Hue for more information. For instance the value
# 0 represents red, 60 is yellow, 120 is green, 180 is cyan, 240 is blue, 300
# purple, and 360 is red again.
# Minimum value: 0, maximum value: 359, default value: 220.
# This tag requires that the tag GENERATE_HTML is set to YES.
HTML_COLORSTYLE_HUE = 220
HTML_COLORSTYLE_HUE = 189
# The HTML_COLORSTYLE_SAT tag controls the purity (or saturation) of the colors
# in the HTML output. For a value of 0 the output will use grayscales only. A
@@ -1222,7 +1254,7 @@ HTML_COLORSTYLE_HUE = 220
# Minimum value: 0, maximum value: 255, default value: 100.
# This tag requires that the tag GENERATE_HTML is set to YES.
HTML_COLORSTYLE_SAT = 100
HTML_COLORSTYLE_SAT = 12
# The HTML_COLORSTYLE_GAMMA tag controls the gamma correction applied to the
# luminance component of the colors in the HTML output. Values below 100
@@ -1233,7 +1265,7 @@ HTML_COLORSTYLE_SAT = 100
# Minimum value: 40, maximum value: 240, default value: 80.
# This tag requires that the tag GENERATE_HTML is set to YES.
HTML_COLORSTYLE_GAMMA = 80
HTML_COLORSTYLE_GAMMA = 240
# If the HTML_TIMESTAMP tag is set to YES then the footer of each generated HTML
# page will contain the date and time when the page was generated. Setting this
@@ -1244,6 +1276,17 @@ HTML_COLORSTYLE_GAMMA = 80
HTML_TIMESTAMP = NO
# If the HTML_DYNAMIC_MENUS tag is set to YES then the generated HTML
# documentation will contain a main index with vertical navigation menus that
# are dynamically created via Javascript. If disabled, the navigation index will
# consists of multiple levels of tabs that are statically embedded in every HTML
# page. Disable this option to support browsers that do not have Javascript,
# like the Qt help browser.
# The default value is: YES.
# This tag requires that the tag GENERATE_HTML is set to YES.
HTML_DYNAMIC_MENUS = NO
# If the HTML_DYNAMIC_SECTIONS tag is set to YES then the generated HTML
# documentation will contain sections that can be hidden and shown after the
# page has loaded.
@@ -1267,13 +1310,13 @@ HTML_INDEX_NUM_ENTRIES = 100
# If the GENERATE_DOCSET tag is set to YES, additional index files will be
# generated that can be used as input for Apple's Xcode 3 integrated development
# environment (see: http://developer.apple.com/tools/xcode/), introduced with
# OSX 10.5 (Leopard). To create a documentation set, doxygen will generate a
# environment (see: https://developer.apple.com/xcode/), introduced with OSX
# 10.5 (Leopard). To create a documentation set, doxygen will generate a
# Makefile in the HTML output directory. Running make will produce the docset in
# that directory and running make install will install the docset in
# ~/Library/Developer/Shared/Documentation/DocSets so that Xcode will find it at
# startup. See http://developer.apple.com/tools/creatingdocsetswithdoxygen.html
# for more information.
# startup. See https://developer.apple.com/library/archive/featuredarticles/Doxy
# genXcode/_index.html for more information.
# The default value is: NO.
# This tag requires that the tag GENERATE_HTML is set to YES.
@@ -1312,7 +1355,7 @@ DOCSET_PUBLISHER_NAME = Publisher
# If the GENERATE_HTMLHELP tag is set to YES then doxygen generates three
# additional HTML index files: index.hhp, index.hhc, and index.hhk. The
# index.hhp is a project file that can be read by Microsoft's HTML Help Workshop
# (see: http://www.microsoft.com/en-us/download/details.aspx?id=21138) on
# (see: https://www.microsoft.com/en-us/download/details.aspx?id=21138) on
# Windows.
#
# The HTML Help Workshop contains a compiler that can convert all HTML output
@@ -1388,7 +1431,7 @@ QCH_FILE =
# The QHP_NAMESPACE tag specifies the namespace to use when generating Qt Help
# Project output. For more information please see Qt Help Project / Namespace
# (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#namespace).
# (see: http://doc.qt.io/archives/qt-4.8/qthelpproject.html#namespace).
# The default value is: org.doxygen.Project.
# This tag requires that the tag GENERATE_QHP is set to YES.
@@ -1396,7 +1439,7 @@ QHP_NAMESPACE = org.doxygen.Project
# The QHP_VIRTUAL_FOLDER tag specifies the namespace to use when generating Qt
# Help Project output. For more information please see Qt Help Project / Virtual
# Folders (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#virtual-
# Folders (see: http://doc.qt.io/archives/qt-4.8/qthelpproject.html#virtual-
# folders).
# The default value is: doc.
# This tag requires that the tag GENERATE_QHP is set to YES.
@@ -1405,7 +1448,7 @@ QHP_VIRTUAL_FOLDER = doc
# If the QHP_CUST_FILTER_NAME tag is set, it specifies the name of a custom
# filter to add. For more information please see Qt Help Project / Custom
# Filters (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#custom-
# Filters (see: http://doc.qt.io/archives/qt-4.8/qthelpproject.html#custom-
# filters).
# This tag requires that the tag GENERATE_QHP is set to YES.
@@ -1413,7 +1456,7 @@ QHP_CUST_FILTER_NAME =
# The QHP_CUST_FILTER_ATTRS tag specifies the list of the attributes of the
# custom filter to add. For more information please see Qt Help Project / Custom
# Filters (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#custom-
# Filters (see: http://doc.qt.io/archives/qt-4.8/qthelpproject.html#custom-
# filters).
# This tag requires that the tag GENERATE_QHP is set to YES.
@@ -1421,7 +1464,7 @@ QHP_CUST_FILTER_ATTRS =
# The QHP_SECT_FILTER_ATTRS tag specifies the list of the attributes this
# project's filter section matches. Qt Help Project / Filter Attributes (see:
# http://qt-project.org/doc/qt-4.8/qthelpproject.html#filter-attributes).
# http://doc.qt.io/archives/qt-4.8/qthelpproject.html#filter-attributes).
# This tag requires that the tag GENERATE_QHP is set to YES.
QHP_SECT_FILTER_ATTRS =
@@ -1462,7 +1505,7 @@ ECLIPSE_DOC_ID = org.doxygen.Project
# The default value is: NO.
# This tag requires that the tag GENERATE_HTML is set to YES.
DISABLE_INDEX = NO
DISABLE_INDEX = YES
# The GENERATE_TREEVIEW tag is used to specify whether a tree-like index
# structure should be generated to display hierarchical information. If the tag
@@ -1479,7 +1522,7 @@ DISABLE_INDEX = NO
# The default value is: NO.
# This tag requires that the tag GENERATE_HTML is set to YES.
GENERATE_TREEVIEW = NO
GENERATE_TREEVIEW = YES
# The ENUM_VALUES_PER_LINE tag can be used to set the number of enum values that
# doxygen will group on one line in the generated HTML documentation.
@@ -1496,7 +1539,7 @@ ENUM_VALUES_PER_LINE = 4
# Minimum value: 0, maximum value: 1500, default value: 250.
# This tag requires that the tag GENERATE_HTML is set to YES.
TREEVIEW_WIDTH = 250
TREEVIEW_WIDTH = 180
# If the EXT_LINKS_IN_WINDOW option is set to YES, doxygen will open links to
# external symbols imported via tag files in a separate window.
@@ -1514,7 +1557,7 @@ EXT_LINKS_IN_WINDOW = NO
FORMULA_FONTSIZE = 10
# Use the FORMULA_TRANPARENT tag to determine whether or not the images
# Use the FORMULA_TRANSPARENT tag to determine whether or not the images
# generated for formulas are transparent PNGs. Transparent PNGs are not
# supported properly for IE 6.0, but are supported on all modern browsers.
#
@@ -1526,7 +1569,7 @@ FORMULA_FONTSIZE = 10
FORMULA_TRANSPARENT = YES
# Enable the USE_MATHJAX option to render LaTeX formulas using MathJax (see
# http://www.mathjax.org) which uses client side Javascript for the rendering
# https://www.mathjax.org) which uses client side Javascript for the rendering
# instead of using pre-rendered bitmaps. Use this if you do not have LaTeX
# installed or if you want to formulas look prettier in the HTML output. When
# enabled you may also need to install MathJax separately and configure the path
@@ -1553,8 +1596,8 @@ MATHJAX_FORMAT = HTML-CSS
# MATHJAX_RELPATH should be ../mathjax. The default value points to the MathJax
# Content Delivery Network so you can quickly see the result without installing
# MathJax. However, it is strongly recommended to install a local copy of
# MathJax from http://www.mathjax.org before deployment.
# The default value is: http://cdn.mathjax.org/mathjax/latest.
# MathJax from https://www.mathjax.org before deployment.
# The default value is: https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/.
# This tag requires that the tag USE_MATHJAX is set to YES.
MATHJAX_RELPATH = http://cdn.mathjax.org/mathjax/latest
@@ -1615,7 +1658,7 @@ SERVER_BASED_SEARCH = NO
#
# Doxygen ships with an example indexer (doxyindexer) and search engine
# (doxysearch.cgi) which are based on the open source search engine library
# Xapian (see: http://xapian.org/).
# Xapian (see: https://xapian.org/).
#
# See the section "External Indexing and Searching" for details.
# The default value is: NO.
@@ -1628,7 +1671,7 @@ EXTERNAL_SEARCH = NO
#
# Doxygen ships with an example indexer (doxyindexer) and search engine
# (doxysearch.cgi) which are based on the open source search engine library
# Xapian (see: http://xapian.org/). See the section "External Indexing and
# Xapian (see: https://xapian.org/). See the section "External Indexing and
# Searching" for details.
# This tag requires that the tag SEARCHENGINE is set to YES.
@@ -1680,21 +1723,34 @@ LATEX_OUTPUT = latex
# The LATEX_CMD_NAME tag can be used to specify the LaTeX command name to be
# invoked.
#
# Note that when enabling USE_PDFLATEX this option is only used for generating
# bitmaps for formulas in the HTML output, but not in the Makefile that is
# written to the output directory.
# The default file is: latex.
# Note that when not enabling USE_PDFLATEX the default is latex when enabling
# USE_PDFLATEX the default is pdflatex and when in the later case latex is
# chosen this is overwritten by pdflatex. For specific output languages the
# default can have been set differently, this depends on the implementation of
# the output language.
# This tag requires that the tag GENERATE_LATEX is set to YES.
LATEX_CMD_NAME = latex
# The MAKEINDEX_CMD_NAME tag can be used to specify the command name to generate
# index for LaTeX.
# Note: This tag is used in the Makefile / make.bat.
# See also: LATEX_MAKEINDEX_CMD for the part in the generated output file
# (.tex).
# The default file is: makeindex.
# This tag requires that the tag GENERATE_LATEX is set to YES.
MAKEINDEX_CMD_NAME = makeindex
# The LATEX_MAKEINDEX_CMD tag can be used to specify the command name to
# generate index for LaTeX.
# Note: This tag is used in the generated output file (.tex).
# See also: MAKEINDEX_CMD_NAME for the part in the Makefile / make.bat.
# The default value is: \makeindex.
# This tag requires that the tag GENERATE_LATEX is set to YES.
LATEX_MAKEINDEX_CMD = \makeindex
# If the COMPACT_LATEX tag is set to YES, doxygen generates more compact LaTeX
# documents. This may be useful for small projects and may help to save some
# trees in general.
@@ -1815,7 +1871,7 @@ LATEX_SOURCE_CODE = NO
# The LATEX_BIB_STYLE tag can be used to specify the style to use for the
# bibliography, e.g. plainnat, or ieeetr. See
# http://en.wikipedia.org/wiki/BibTeX and \cite for more info.
# https://en.wikipedia.org/wiki/BibTeX and \cite for more info.
# The default value is: plain.
# This tag requires that the tag GENERATE_LATEX is set to YES.
@@ -1829,6 +1885,14 @@ LATEX_BIB_STYLE = plain
LATEX_TIMESTAMP = NO
# The LATEX_EMOJI_DIRECTORY tag is used to specify the (relative or absolute)
# path from which the emoji images will be read. If a relative path is entered,
# it will be relative to the LATEX_OUTPUT directory. If left blank the
# LATEX_OUTPUT directory will be used.
# This tag requires that the tag GENERATE_LATEX is set to YES.
LATEX_EMOJI_DIRECTORY =
#---------------------------------------------------------------------------
# Configuration options related to the RTF output
#---------------------------------------------------------------------------
@@ -1868,9 +1932,9 @@ COMPACT_RTF = NO
RTF_HYPERLINKS = NO
# Load stylesheet definitions from file. Syntax is similar to doxygen's config
# file, i.e. a series of assignments. You only have to provide replacements,
# missing definitions are set to their default value.
# Load stylesheet definitions from file. Syntax is similar to doxygen's
# configuration file, i.e. a series of assignments. You only have to provide
# replacements, missing definitions are set to their default value.
#
# See also section "Doxygen usage" for information on how to generate the
# default style sheet that doxygen normally uses.
@@ -1879,8 +1943,8 @@ RTF_HYPERLINKS = NO
RTF_STYLESHEET_FILE =
# Set optional variables used in the generation of an RTF document. Syntax is
# similar to doxygen's config file. A template extensions file can be generated
# using doxygen -e rtf extensionFile.
# similar to doxygen's configuration file. A template extensions file can be
# generated using doxygen -e rtf extensionFile.
# This tag requires that the tag GENERATE_RTF is set to YES.
RTF_EXTENSIONS_FILE =
@@ -1966,6 +2030,13 @@ XML_OUTPUT = xml
XML_PROGRAMLISTING = YES
# If the XML_NS_MEMB_FILE_SCOPE tag is set to YES, doxygen will include
# namespace members in file scope as well, matching the HTML output.
# The default value is: NO.
# This tag requires that the tag GENERATE_XML is set to YES.
XML_NS_MEMB_FILE_SCOPE = NO
#---------------------------------------------------------------------------
# Configuration options related to the DOCBOOK output
#---------------------------------------------------------------------------
@@ -1998,9 +2069,9 @@ DOCBOOK_PROGRAMLISTING = NO
#---------------------------------------------------------------------------
# If the GENERATE_AUTOGEN_DEF tag is set to YES, doxygen will generate an
# AutoGen Definitions (see http://autogen.sf.net) file that captures the
# structure of the code including all documentation. Note that this feature is
# still experimental and incomplete at the moment.
# AutoGen Definitions (see http://autogen.sourceforge.net/) file that captures
# the structure of the code including all documentation. Note that this feature
# is still experimental and incomplete at the moment.
# The default value is: NO.
GENERATE_AUTOGEN_DEF = NO
@@ -2100,7 +2171,7 @@ INCLUDE_FILE_PATTERNS =
# recursively expanded use the := operator instead of the = operator.
# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
PREDEFINED = @DOXYGEN_PREDEFINED_MACROS@
PREDEFINED =
# If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
# tag can be used to specify a list of macro names that should be expanded. The
@@ -2184,7 +2255,7 @@ PERL_PATH = /usr/bin/perl
# powerful graphs.
# The default value is: YES.
CLASS_DIAGRAMS = NO
CLASS_DIAGRAMS = YES
# You can define message sequence charts within doxygen comments using the \msc
# command. Doxygen will then run the mscgen tool (see:
@@ -2213,9 +2284,9 @@ HIDE_UNDOC_RELATIONS = YES
# http://www.graphviz.org/), a graph visualization toolkit from AT&T and Lucent
# Bell Labs. The other options in this section have no effect if this option is
# set to NO
# The default value is: YES.
# The default value is: NO.
HAVE_DOT = YES
HAVE_DOT = NO
# The DOT_NUM_THREADS specifies the number of dot invocations doxygen is allowed
# to run in parallel. When set to 0 doxygen will base this on the number of
@@ -2369,9 +2440,7 @@ DIRECTORY_GRAPH = YES
# Note: If you choose svg you need to set HTML_FILE_EXTENSION to xhtml in order
# to make the SVG files visible in IE 9+ (other browsers do not have this
# requirement).
# Possible values are: png, png:cairo, png:cairo:cairo, png:cairo:gd, png:gd,
# png:gd:gd, jpg, jpg:cairo, jpg:cairo:gd, jpg:gd, jpg:gd:gd, gif, gif:cairo,
# gif:cairo:gd, gif:gd, gif:gd:gd, svg, png:gd, png:gd:gd, png:cairo,
# Possible values are: png, jpg, gif, svg, png:gd, png:gd:gd, png:cairo,
# png:cairo:gd, png:cairo:cairo, png:cairo:gdiplus, png:gdiplus and
# png:gdiplus:gdiplus.
# The default value is: png.
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