Bug 1541943 - Temporarily switch libFuzzer builds back to clang-7. r=froydnj

Differential Revision: https://phabricator.services.mozilla.com/D26194

--HG--
extra : moz-landing-system : lando

build/build-clang/clang-7-linux64.json

@@ -0,0 +1,25 @@
+{
+    "llvm_revision": "349247",
+    "stages": "3",
+    "build_libcxx": true,
+    "build_type": "Release",
+    "assertions": false,
+    "llvm_repo": "https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_701/final",
+    "clang_repo": "https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_701/final",
+    "lld_repo": "https://llvm.org/svn/llvm-project/lld/tags/RELEASE_701/final",
+    "compiler_repo": "https://llvm.org/svn/llvm-project/compiler-rt/tags/RELEASE_701/final",
+    "libcxx_repo": "https://llvm.org/svn/llvm-project/libcxx/tags/RELEASE_701/final",
+    "libcxxabi_repo": "https://llvm.org/svn/llvm-project/libcxxabi/tags/RELEASE_701/final",
+    "python_path": "/usr/bin/python2.7",
+    "gcc_dir": "/builds/worker/workspace/build/src/gcc",
+    "cc": "/builds/worker/workspace/build/src/gcc/bin/gcc",
+    "cxx": "/builds/worker/workspace/build/src/gcc/bin/g++",
+    "as": "/builds/worker/workspace/build/src/gcc/bin/gcc",
+    "patches": [
+      "static-llvm-symbolizer.patch",
+      "find_symbolizer_linux.patch",
+      "rename_gcov_flush_7.patch",
+      "r350774.patch",
+      "android-mangling-error.patch"
+    ]
+}

build/build-clang/r350774.patch

@@ -0,0 +1,14 @@
+diff --git a/llvm/lib/Object/Binary.cpp b/llvm/lib/Object/Binary.cpp
+index d7c25921ec3..fe41987f5c2 100644
+--- a/llvm/lib/Object/Binary.cpp
++++ b/llvm/lib/Object/Binary.cpp
+@@ -88,7 +88,8 @@ Expected<std::unique_ptr<Binary>> object::createBinary(MemoryBufferRef Buffer,
+ 
+ Expected<OwningBinary<Binary>> object::createBinary(StringRef Path) {
+   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
+-      MemoryBuffer::getFileOrSTDIN(Path);
++      MemoryBuffer::getFileOrSTDIN(Path, /*FileSize=*/-1,
++                                   /*RequiresNullTerminator=*/false);
+   if (std::error_code EC = FileOrErr.getError())
+     return errorCodeToError(EC);
+   std::unique_ptr<MemoryBuffer> &Buffer = FileOrErr.get();

build/build-clang/rename_gcov_flush_7.patch

@@ -0,0 +1,14 @@
+Index: compiler-rt/lib/profile/GCDAProfiling.c
+===================================================================
+diff --git a/compiler-rt/lib/profile/GCDAProfiling.c b/compiler-rt/lib/profile/GCDAProfiling.c
+--- a/compiler-rt/lib/profile/GCDAProfiling.c	(revisione 336380)
++++ b/compiler-rt/lib/profile/GCDAProfiling.c	(copia locale)
+@@ -555,7 +555,7 @@
+   fn_list_insert(&flush_fn_list, fn);
+ }
+ 
+-void __gcov_flush() {
++void __custom_llvm_gcov_flush() {
+   struct fn_node* curr = flush_fn_list.head;
+ 
+   while (curr) {

taskcluster/ci/build/linux.yml

@@ -639,7 +639,7 @@ linux64-asan-fuzzing/opt:
         need-xvfb: true
     toolchains:
         - linux64-binutils
-        - linux64-clang
+        - linux64-clang-7
         - linux64-rust
         - linux64-rust-size
         - linux64-cbindgen
@@ -674,7 +674,7 @@ linux64-asan-fuzzing-ccov/opt:
         need-xvfb: true
     toolchains:
         - linux64-binutils
-        - linux64-clang
+        - linux64-clang-7
         - linux64-rust
         - linux64-rust-size
         - linux64-cbindgen

taskcluster/ci/toolchain/clang.yml

@@ -24,6 +24,21 @@ linux64-clang-4.0:
     toolchains:
         - linux64-gcc-6
 
+linux64-clang-7:
+    description: "Clang 7 toolchain build"
+    treeherder:
+        symbol: TL(clang7)
+    run:
+        using: toolchain-script
+        script: build-clang-7-linux.sh
+        resources:
+            - 'build/build-clang/build-clang.py'
+            - 'build/build-clang/clang-7-linux64.json'
+            - 'taskcluster/scripts/misc/tooltool-download.sh'
+        toolchain-artifact: public/build/clang.tar.xz
+    toolchains:
+        - linux64-gcc-6
+
 linux64-clang-8:
     description: "Clang 8 toolchain build"
     treeherder:

taskcluster/scripts/misc/build-clang-7-linux.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+set -x -e -v
+
+# This script is for building clang for Linux.
+
+WORKSPACE=$HOME/workspace
+HOME_DIR=$WORKSPACE/build
+UPLOAD_DIR=$HOME/artifacts
+
+cd $HOME_DIR/src
+
+. taskcluster/scripts/misc/tooltool-download.sh
+
+# gets a bit too verbose here
+set +x
+
+cd build/build-clang
+# |mach python| sets up a virtualenv for us!
+../../mach python ./build-clang.py -c clang-7-linux64.json
+
+set -x
+
+# Put a tarball in the artifacts dir
+mkdir -p $UPLOAD_DIR
+cp clang.tar.* $UPLOAD_DIR