Commit Graph

630 Commits

Author SHA1 Message Date
Alexander Richardson
b9aa9a5500 [ELF] Don't crash when parsing a file with out-of-bounds version references
Summary:
We were crashing when linking telnetd in FreeBSD because lld was emitting
corrupted output files for --norosegment. In this file the version index of some symbols
was set to 9 but lld only found 8 version definitions.

I am not sure how to create a minimal .so file that also exposes this behaviour so I just added the one that initially caused the error to Inputs/

This partially addresses https://bugs.llvm.org/show_bug.cgi?id=34705

Reviewers: ruiu, rafael, pcc, grimar

Reviewed By: ruiu

Subscribers: emaste, krytarowski

Tags: #lld

Differential Revision: https://reviews.llvm.org/D38397

llvm-svn: 315036
2017-10-05 23:28:34 +00:00
Alexander Richardson
57f089775b [ELF] Don't crash when parsing a file with external version definition references
Summary:
We were crashing when linking telnetd in FreeBSD because lld was emitting
corrupted output files for --norosegment. In this file the version index of some symbols
was set to 9 but lld only found 8 version definitions.

I am not sure how to create a minimal .so file that also exposes this behaviour so I just added the one that initially caused the error to Inputs/

This partially addresses https://bugs.llvm.org/show_bug.cgi?id=34705

Reviewers: ruiu, rafael, pcc, grimar

Reviewed By: ruiu

Subscribers: emaste, krytarowski

Tags: #lld

Differential Revision: https://reviews.llvm.org/D38397

llvm-svn: 315035
2017-10-05 23:28:29 +00:00
George Rimar
ed906d8e63 [ELF] - Update after LLVM r314883 change. NFC.
llvm-svn: 314884
2017-10-04 08:50:34 +00:00
Rui Ueyama
de3d0cc894 Make parameter lists of SymbolTable::add* functions more consistent. NFC.
llvm-svn: 314591
2017-09-30 12:41:34 +00:00
George Rimar
696a7f9ac6 [ELF] - Introduce std::vector<InputFile *> global arrays.
This patch removes lot of static Instances arrays from different input file 
classes and introduces global arrays for access instead. Similar to arrays we
have for InputSections/OutputSectionCommands.

It allows to iterate over input files in a non-templated code.

Differential revision: https://reviews.llvm.org/D35987

llvm-svn: 313619
2017-09-19 09:20:54 +00:00
James Henderson
7594c61d2d [ELF] Prevent crash with binary inputs with non-ascii file names
If using --format=binary with an input file name that has one or more non-ascii
characters in, LLD has undefined behaviour (it crashes on my Windows Debug build)
when calling isalnum with these non-ascii characters. Instead, of calling
std::isalnum, this patch uses an internal version that ignores the locale and
checks a specific subset of characters.

Reviewers: ruiu

Differential Revision: https://reviews.llvm.org/D37331

llvm-svn: 312705
2017-09-07 08:30:09 +00:00
Rui Ueyama
42479e02ca Rename {Lazy,}ObjectKind -> {Lazy,}ObjKind.
I renamed corresponding classes in r309199 but forgot to rename enums
at the moment. Rename them now to make them consistent.

llvm-svn: 311214
2017-08-19 00:13:54 +00:00
Rafael Espindola
6e93d0546a Move File from SymbolBody to Symbol.
With this Symbol has the same size as before, but DefinedRegular goes
from 72 to 64 bytes.

I also find this a bit easier to read. There are fewer places
initializing File for example.

This has a small but measurable speed improvement on all tests (1%
max).

llvm-svn: 310142
2017-08-04 22:31:42 +00:00
George Rimar
70ecb827b4 [ELF] - Move getSymbols() methods to InputFile.
It can help to detemplate code.

Differential revision: https://reviews.llvm.org/D35936

llvm-svn: 310049
2017-08-04 11:07:42 +00:00
Rafael Espindola
3a8e4d98f8 Use more consistent names
Reviewing another change I noticed that we use "getSymbols" to mean
different things in different files. Depending on the file it can
return

ArrayRef<StringRef>
ArrayRef<SymbolBody*>
ArrayRef<Symbol*>
ArrayRef<Elf_Sym>

With this change it always returns an ArrayRef<SymbolBody*>. The other
functions are renamed getELFsyms() and getSymbolNames().

Note that we cannot return ArrayRef<Symbol*> instead of
ArreyRef<SymbolBody*> because local symbols have a SymbolBody but not
a Symbol.

llvm-svn: 309840
2017-08-02 17:35:18 +00:00
Rui Ueyama
709fb2bb10 Rename ObjectFile -> ObjFile.
Rename it because it was too easy to conflict with llvm::object::ObjectFile
which broke buildbots several times.

llvm-svn: 309199
2017-07-26 22:13:32 +00:00
Rui Ueyama
23f64d229b Remove unnecessary namespace specifier.
I believe this compiles fine on all platforms, even on Windows.

llvm-svn: 309182
2017-07-26 21:24:01 +00:00
Rafael Espindola
244ef98161 Detemplate SymbolTable.
NFC, just makes it easier to access from non templated code.

llvm-svn: 309152
2017-07-26 18:42:48 +00:00
Igor Kudrin
7d2b15a7ab [ELF] Avoid data race in ObjectFile<ELFT>::getDILineInfo().
Differential Revision: https://reviews.llvm.org/D35537

llvm-svn: 308728
2017-07-21 11:26:08 +00:00
Rui Ueyama
875ae82b0b Add the --chroot option for --reproduce.
Summary:
If the linker is invoked with `--chroot /foo` and `/bar/baz.o`, it
tries to read the file from `/foo/bar/baz.o`. This feature is useful
when you are dealing with files created by the --reproduce option.

Reviewers: grimar

Subscribers: llvm-commits, emaste

Differential Revision: https://reviews.llvm.org/D35517

llvm-svn: 308646
2017-07-20 18:17:55 +00:00
Rafael Espindola
8b1afd59c3 Speed up gdb index creation.
With that in place we can use lld's own infrastructure for the low
level detail of dwarf parsing.

With this we don't decompress sections twice, we don't scan all
realocations and even with this simplistic implementation linking
clang with gdb index goes from 34.09 seconds to 20.80 seconds.

llvm-svn: 308544
2017-07-19 22:27:35 +00:00
David Blaikie
15309044ba Use LoadedObjectInfoHelper to simplify/delegate the implementation of 'clone'
llvm-svn: 307167
2017-07-05 15:24:42 +00:00
Paul Robinson
c60318af24 Tweak to match change in LLVM API, in r306699
llvm-svn: 306700
2017-06-29 16:52:29 +00:00
Rui Ueyama
d1f8b8162b Implement the --exclude-libs option.
The --exclude-libs option is not a popular option, but at least some
programs in Android depend on it, so it's worth to support it.

Differential Revision: https://reviews.llvm.org/D34422

llvm-svn: 305920
2017-06-21 15:36:24 +00:00
Leslie Zhai
49ba795d15 [ELF] Initial migration of AVR target
Reviewers: ruiu, rafael, grimar, atanasyan, psmith, dylanmckay

Reviewed By: ruiu, rafael, grimar, dylanmckay

Differential Revision: https://reviews.llvm.org/D32991

llvm-svn: 305444
2017-06-15 02:27:50 +00:00
Rui Ueyama
f9f69548a9 Allow the GNU gold-style nonstandard SHT_GROUP section.
The ELF standard defines that the SHT_GROUP section as follows:

 - its sh_link has the symbol index, and
 - the symbol name is used to uniquify section groups.

Object files created by GNU gold does not seem to comply with the
standard. They have this additional rule:

 - if the symbol has no name and a STT_SECTION symbol, a section
   name is used instead of a symbol name.

If we don't do anything for this, the linker fails with a mysterious
error message if input files are generated by gas. It is unfortunate
but I think we need to support it.

Differential Revision: https://reviews.llvm.org/D34064

llvm-svn: 305218
2017-06-12 18:46:33 +00:00
Rui Ueyama
a1ba859ad3 Simplify. NFC.
llvm-svn: 305047
2017-06-09 02:42:20 +00:00
George Rimar
3b189d1643 [ELF] - Do not allow -r to eat comdats.
This is PR33052, "Bug 33052 - -r eats comdats ".

To fix it I stop removing group section from out when -r is given
and fixing SHT_GROUP content when writing it just like we do some
other fixup, e.g. for Rel[a]. (it needs fix for section indices that
are in group).

Differential revision: https://reviews.llvm.org/D33485

llvm-svn: 304140
2017-05-29 08:37:50 +00:00
Rui Ueyama
240b9515e2 Simplify. NFC.
llvm-svn: 303959
2017-05-26 02:17:30 +00:00
Rafael Espindola
1c2baad6dd Revert "Simplify a variable type by using StringRef instead of CachedHashStringRef."
This reverts commit r303787.

It caused a slowdown in fast links. That is, links with no debug info
or optimizations.

llvm-svn: 303925
2017-05-25 21:53:02 +00:00
Rui Ueyama
466c82b74f Simplify a variable type by using StringRef instead of CachedHashStringRef.
A variable `ComdatGroup` is not supposed to contain a large number of
items. Even when linking clang, it ends up having only 300K strings.
It doesn't make sense to use CachedHashStringRef for this hash table.
This patch has neutral or slightly positive impact on performance while
reducing code complexity.

llvm-svn: 303787
2017-05-24 18:22:27 +00:00
Rafael Espindola
895aea6d15 Reduce template usage. NFC.
llvm-svn: 302832
2017-05-11 22:02:41 +00:00
Rafael Espindola
0f6cc65fe9 Remember OffsetInArchive in LazyObjectFile.
LazyObjectFile might turn out to be a BitcodeFile, so we need
OffsetInArchive.

llvm-svn: 302242
2017-05-05 15:17:07 +00:00
Rafael Espindola
80ae8ae186 Remember archive name when creating LazyObjectFile.
It is needed for creating an unique identifier for ThinLTO.

This fixes pr32931.

llvm-svn: 302235
2017-05-05 13:55:51 +00:00
Rafael Espindola
808f2d3c62 Reduce code duplication. NFC.
llvm-svn: 302155
2017-05-04 14:54:48 +00:00
Rui Ueyama
fd7deda57a Accept archive files with no symbol table instad of warning on them.
It seems virtually everyone who tries to do LTO build with Clang and
LLD was hit by a mistake to forget using llvm-ar command to create
archive files. I wasn't an exception. Since this is an annoying common
issue, it is probably better to handle that gracefully rather than
reporting an error and tell the user to redo build with different
configuration.

Differential Revision: https://reviews.llvm.org/D32721

llvm-svn: 302083
2017-05-03 21:03:08 +00:00
Rui Ueyama
c344313803 Fix typo.
llvm-svn: 301975
2017-05-02 21:16:06 +00:00
Rui Ueyama
dfb1e2a1a1 Update commetns.
llvm-svn: 301896
2017-05-02 02:58:04 +00:00
Rui Ueyama
92a8d798b8 Add comments about how we handle mergeable sections with relocations.
Also factored out code.

llvm-svn: 301833
2017-05-01 20:49:09 +00:00
Davide Italiano
d765638ad1 [ELF] When a rel points to a SHF_MERGE section, don't merge the sec.
Fixes PR32785. Thanks to Piotr Padlewski for the report and
Rafael for the fix.

llvm-svn: 301729
2017-04-29 01:24:34 +00:00
Rui Ueyama
e2f11690fe Eliminate .debug_gnu_pub{names,types} if -gdb-index is given.
This patch is to ignore .debug_gnu_pub{names,types} sections if the
-gdb-index option was given.

Differential Revision: https://reviews.llvm.org/D32662

llvm-svn: 301710
2017-04-28 22:46:55 +00:00
Rui Ueyama
8a3ef95fc9 Use toString(Inputfile*) to format a file object.
llvm-svn: 301674
2017-04-28 20:00:09 +00:00
Rui Ueyama
c9d82b9e16 Simplify BinaryFile::parse and add comments.
llvm-svn: 301514
2017-04-27 04:01:36 +00:00
Rui Ueyama
63d48e5956 Remove needless type conversions.
llvm-svn: 301513
2017-04-27 04:01:14 +00:00
Rui Ueyama
e5ad2986fc Remove unnecessary instantiation of StringRef.
SoName's type has changed from StringRef to std::string, so this
code does not make sense anymore.

llvm-svn: 301490
2017-04-26 23:00:32 +00:00
Rui Ueyama
330e52b018 Removes createELFFile which takes a template class as a template parameter.
This patch is to reduce amount of template uses. The new code is less
exciting and boring than before, but I think it is easier to read.

Differential Revision: https://reviews.llvm.org/D32467

llvm-svn: 301488
2017-04-26 22:51:51 +00:00
Rafael Espindola
3460cdd440 Remove DefaultSoName.
We can just use the existing SoName member variable. It now initially
contains what was in DefaultSoName and is modified if the .so has an
actual soname.

llvm-svn: 301259
2017-04-24 21:44:20 +00:00
Peter Collingbourne
8446f1fe6a Object, LTO: Add target triple to irsymtab and LTO API.
Start using it in LLD to avoid needing to read bitcode again just to get the
target triple, and in llvm-lto2 to avoid printing symbol table information
that is inappropriate for the target.

Differential Revision: https://reviews.llvm.org/D32038

llvm-svn: 300300
2017-04-14 02:55:06 +00:00
Peter Collingbourne
c0987938ea ELF: Remove some dead code.
llvm-svn: 300297
2017-04-14 02:34:32 +00:00
Rui Ueyama
3233d3eb46 Do not initialize this->SoName with this->DefaultSoName.
This patch uses DefaultSoName in getSoName instead of in parseSoName.
I think this is more readable. This patch also add comments.

llvm-svn: 300147
2017-04-13 00:23:32 +00:00
Evgeniy Stepanov
a76349bffe [lld] Keep full library path in DT_NEEDED.
Fixes PR32572.

When
    (a) a library has no soname
and (b) library is given on the command line with path (and not through -L/-l flags)
DT_NEEDED entry for such library keeps the path as given.

This behavior is consistent with gold and bfd, and is used in compiler-rt test suite.

This is a second attempt after r300007 got reverted. This time relro-omagic test is
changed in a way to avoid hardcoding the path to the test directory in the objdump'd
binary.

llvm-svn: 300011
2017-04-12 00:13:48 +00:00
Evgeniy Stepanov
d512afe3da Revert "[lld] Keep full library path in DT_NEEDED."
This reverts commit r300007. Reason: breaks all the bots.

llvm-svn: 300008
2017-04-12 00:01:21 +00:00
Evgeniy Stepanov
2c2dcae13c [lld] Keep full library path in DT_NEEDED.
Fixes PR32572.

When
    (a) a library has no soname
and (b) library is given on the command line with path (and not through -L/-l flags)
DT_NEEDED entry for such library keeps the path as given.

This behavior is consistent with gold and bfd, and is used in compiler-rt test suite.

llvm-svn: 300007
2017-04-11 23:46:58 +00:00
Rui Ueyama
4e4e8662bc Remove InputFiles::LogName.
LogName member was added to construct input file names for logging
only once. This patch does this in a different way. Now toString
caches its results.

Differential Revision: https://reviews.llvm.org/D31546

llvm-svn: 299375
2017-04-03 19:11:23 +00:00
Peter Collingbourne
7b30f16c9f Re-apply r299168 and r299169 now that the libdeps are fixed.
llvm-svn: 299184
2017-03-31 04:47:07 +00:00
Peter Collingbourne
f10698b940 Revert r299168 and r299169 due to library dependency issues.
http://bb.pgr.jp/builders/i686-mingw32-RA-on-linux/builds/25073/steps/build_llvmclang/logs/stdio

llvm-svn: 299171
2017-03-31 02:44:50 +00:00
Peter Collingbourne
d9717aa0e4 LTO: Reduce memory consumption by creating an in-memory symbol table for InputFiles. NFCI.
Introduce symbol table data structures that can be potentially written to
disk, have the LTO library build those data structures using temporarily
constructed modules and redirect the LTO library implementation to go through
those data structures. This allows us to remove the LLVMContext and Modules
owned by InputFile.

With this change I measured a peak memory consumption decrease from 5.4GB to
2.8GB in a no-op incremental ThinLTO link of Chromium on Linux. The impact on
memory consumption is larger in COFF linkers where we are currently forced
to materialize all metadata in order to read linker options. Peak memory
consumption linking a large piece of Chromium for Windows with full LTO and
debug info decreases from >64GB (OOM) to 15GB.

Part of PR27551.

Differential Revision: https://reviews.llvm.org/D31364

llvm-svn: 299168
2017-03-31 02:28:30 +00:00
Rui Ueyama
37e60a52f3 Include filenames in error messages to report broken files.
llvm-svn: 299115
2017-03-30 21:13:00 +00:00
Rui Ueyama
b87602032a Change the error message format for undefined symbols.
Previously, undefined symbol errors are one line like this
and wasn't easy to read.

  /ssd/clang/bin/ld.lld: error: /ssd/llvm-project/lld/ELF/Writer.cpp:207: undefined symbol 'lld:🧝:EhFrameSection<llvm::object::ELFType<(llvm::support::endianness)0, true> >::addSection(lld:🧝:InputSectionBase*)'

This patch make it more structured like this.

  bin/ld.lld: error: undefined symbol: lld:🧝:EhFrameSection<llvm::object::ELFType<(llvm::support::endianness)0, true>
  >>> Referenced by Writer.cpp:207 (/ssd/llvm-project/lld/ELF/Writer.cpp:207)
  >>>               Writer.cpp.o in archive lib/liblldELF.a

Discussion thread:
http://lists.llvm.org/pipermail/llvm-dev/2017-March/111459.html

Differential Revision: https://reviews.llvm.org/D31481

llvm-svn: 299097
2017-03-30 19:13:47 +00:00
Peter Collingbourne
0d56b959ad LTO: Replace InputFile::Symbol::getFlags() with predicate accessors. NFC.
This makes the predicates independent of the flag representation
and makes the code a little easier to read.

llvm-svn: 298951
2017-03-28 22:31:35 +00:00
George Rimar
f56cadd3b3 [ELF] - Fix one more access to Sections member.
That finally should linux BB after r298345.

llvm-svn: 298349
2017-03-21 08:57:13 +00:00
George Rimar
3f7c3df6a4 [ELF] Follow-up to r298345 "[ELF] - Detemplate GdbIndexSection."
Fix for linux build bot:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/8144/steps/build/logs/stdio

llvm-svn: 298348
2017-03-21 08:44:25 +00:00
Rafael Espindola
b57e496dfa Move OffsetInArchive to BitcodeFile.
It is the only file type that needs it.

llvm-svn: 298323
2017-03-20 23:47:06 +00:00
Rui Ueyama
d57e74b7d3 Compute Config member function return values only once.
We had a few Config member functions that returns configuration values.
For example, we had is64() which returns true if the target is 64-bit.
The return values of these functions are constant and never change.

This patch is to compute them only once to make it clear that they'll
never change.

llvm-svn: 298168
2017-03-17 23:29:01 +00:00
Rui Ueyama
fd06b73466 Define Config::isLE and Config::wordsize.
isLE() return true if the target is little-endian.
wordsize() returns 8 for 64-bit and 4 for 32-bit.

llvm-svn: 298167
2017-03-17 23:28:41 +00:00
Bob Haarman
f790f788b6 recommend using llvm-ar when finding undefined references and empty archives
Summary:
When we perform LTO builds with a version of ar that does not
understand LLVM bitcode objects, we end up with undefined references,
because our archive files do not list the bitcode symbols in their
indices. The error messages do not make it clear what the real problem
is. This change adds a note that points out the likely problem and
solution. It is similar in spirit to r282633, but aims to avoid false
positives by only triggering when we see both undefined references and
archives without symbols in their indices.

Fixes PR32281.

Reviewers: davide, ruiu, tejohnson

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31011

llvm-svn: 298124
2017-03-17 21:32:49 +00:00
Rafael Espindola
35ae65ee2b Rename one of the getOffset methods.
It is sufficiently different in that it returns an offset in the input
file, not the output section.

llvm-svn: 297290
2017-03-08 15:57:17 +00:00
Rafael Espindola
bdd2e3e36c Remove redundant member of InputSectionBase. NFC.
With this InputSectionBase is now 144 bytes.

llvm-svn: 297278
2017-03-08 14:12:52 +00:00
Rafael Espindola
5c02b741eb Detemplate EhInputSection. NFC.
llvm-svn: 297077
2017-03-06 21:17:18 +00:00
Rafael Espindola
6119b865ec Detemplate merge (input and synthetic) sections. NFC.
llvm-svn: 297061
2017-03-06 20:23:56 +00:00
Rui Ueyama
175e81cf3a Use make<> instead of new (BAlloc). NFC.
We converted them before, but there were a few remaining occurrences.

llvm-svn: 296510
2017-02-28 19:36:30 +00:00
Rui Ueyama
80474a26b9 De-template DefinedRegular.
Differential Revision: https://reviews.llvm.org/D30348

llvm-svn: 296508
2017-02-28 19:29:55 +00:00
Sean Silva
1d96185f57 Add Triple::thumb to getBitcodeMachineKind
We really need to find a way to get this info from a single point of
truth in the LLVM backend, but it seems that the EM_* constants are
buried deep inside the constructors of the MCAsmBackend's.

For now, just fill in entries as we run into cases. AFAIK these mappings
are largely immutable, so we get a 75% discount on the technical debt
(code is duplicated, but little chance of divergence).

llvm-svn: 296429
2017-02-28 03:00:48 +00:00
Rui Ueyama
9cc84384ad Use uint64_t instead of uintX_t where the larger type just works.
llvm-svn: 296162
2017-02-24 19:52:52 +00:00
Rafael Espindola
774ea7d0a9 Make InputSection a class. NFC.
With the current design an InputSection is basically anything that
goes directly in a OutputSection. That includes plain input section
but also synthetic sections, so this should probably not be a
template.

llvm-svn: 295993
2017-02-23 16:49:07 +00:00
Rui Ueyama
b7f39b08f4 Slightly improve an error message.
llvm-svn: 295942
2017-02-23 07:35:30 +00:00
Rui Ueyama
c1a0ac2c4a Add a comment about .note.GNU-split-stack.
llvm-svn: 295941
2017-02-23 07:35:11 +00:00
Rui Ueyama
65efe35632 Update comment: .note.GNU-stack is added by default today.
llvm-svn: 295939
2017-02-23 07:15:46 +00:00
Rui Ueyama
0633273d05 Update a comment about .note.GNU-stack.
llvm-svn: 295938
2017-02-23 07:06:43 +00:00
Rui Ueyama
6e0142d78c Use isa<MergeInputSection> to check if a section is a merge section.
We have InputSection, MergeInputSection and EhInputSection, so
isa<MergeInputSection> is equivalent to !isa<InputSection> && !isa<
EhInputSection>.

llvm-svn: 295937
2017-02-23 06:47:18 +00:00
Rafael Espindola
b4c9b81aad Convert InputSectionBase to a class.
Removing this template is not a big win by itself, but opens the way
for removing more templates.

llvm-svn: 295923
2017-02-23 02:28:28 +00:00
Rui Ueyama
e6e206d4b4 Do not use errs() or outs() directly. Instead use message(), log() or error()
LLD is a multi-threaded program. errs() or outs() are not guaranteed
to be thread-safe (they are actually not).

LLD's message(), log() or error() are thread-safe. We should use them.

llvm-svn: 295787
2017-02-21 23:22:56 +00:00
George Rimar
858a659a4f [ELF] - Added support of linkerscript's "/DISCARD/" for --emit-relocs
Previously LLD crashed on on provided testcases because "/DISCARD/" was
not supported. Patch implements that.

After this I think there is no known issues with --emit-relocs implementation
required for linux kernel linking.

Differential revision: https://reviews.llvm.org/D29273

llvm-svn: 295488
2017-02-17 19:46:47 +00:00
George Rimar
647c1685b6 [ELF] - Move DependentSections vector from InputSection to InputSectionBase
I splitted it from D29273.
Since we plan to make relocatable sections as dependent for target ones for
--emit-relocs implementation, this change is required to support .eh_frame case.

EhInputSection inherets from InputSectionBase and not from InputSection.
So for case when it has relocation section, it should be able to access DependentSections
vector.

This case is real for Linux kernel.

Differential revision: https://reviews.llvm.org/D30084

llvm-svn: 295483
2017-02-17 19:34:05 +00:00
George Rimar
09015fee3c [ELF] - Allow section to have multiple dependent sections.
That fixes a case when section has more than one metadata 
section. Previously GC would collect one of such sections 
because we had implementation that stored only last one as
dependent.

Differential revision: https://reviews.llvm.org/D29981

llvm-svn: 295298
2017-02-16 08:41:19 +00:00
George Rimar
ee6f22ce0b [ELF] - Do not segfault when using -r and section groups.
If we had SHT_GROUP sections, then when -r was used we might crash.
This is PR31952.

Issue happened because we emited relocation section though its target was discared
because was a member of duplicated group. When we tried to get VA of target,
segfault happened.
Core cause is the bug that GNU as 2.27 (and probably later versions) has.
In compare with llvm-mc, it does not include relocation sections into the group, 
like shown in testcase. This patch covers that case.

Differential revision: https://reviews.llvm.org/D29929

llvm-svn: 295067
2017-02-14 16:42:38 +00:00
George Rimar
82bd8be6d8 Recommit r294464 "[ELF] - Added partial support for --emit-relocs (no --gc-section case, no /DISCARD/ support) #3"
with temporarily file name fix in testcase.

Original commit message:

-q, --emit-relocs - Generate relocations in output

Simplest implementation: 
* no GC case, 
* no "/DISCARD/" linkerscript command support.

This patch is extracted from D28612 / D29636,

Relative to PR31579.

Differential revision: https://reviews.llvm.org/D29663

llvm-svn: 294469
2017-02-08 16:18:10 +00:00
George Rimar
0b2cc8190d Reverted r294464 "[ELF] - Added partial support for --emit-relocs (no --gc-section case, no /DISCARD/ support) #3"
Broked build bot:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/5835/steps/test/logs/stdio

llvm-svn: 294466
2017-02-08 16:10:14 +00:00
George Rimar
d6ae624552 [ELF] - Added partial support for --emit-relocs (no --gc-section case, no /DISCARD/ support) #3
-q, --emit-relocs - Generate relocations in output

Simplest implementation: 
* no GC case, 
* no "/DISCARD/" linkerscript command support.

This patch is extracted from D28612 / D29636,

Relative to PR31579.

Differential revision: https://reviews.llvm.org/D29663

llvm-svn: 294464
2017-02-08 15:53:33 +00:00
Peter Smith
3a52eb0054 [ELF] Use SyntheticSections for Thunks
Thunks are now implemented by redirecting the relocation to the
symbol S, to a symbol TS in a Thunk. The Thunk will transfer control
to S. This has the following implications:
- All the side-effects of Thunks happen within createThunks()
- Thunks are no longer stored in InputSections and Symbols no longer
  need to hold a pointer to a Thunk
- The synthetic Thunk sections need to be merged into OutputSections
    
This implementation is almost a direct conversion of the existing
Thunks with the following exceptions:
- Mips LA25 Thunks are placed before the InputSection that defines
  the symbol that needs a Thunk.
- All ARM Thunks are placed at the end of the OutputSection of the
  first caller to the Thunk.
    
Range extension Thunks are not supported yet so it is optimistically
assumed that all Thunks can be reused.

This is a recommit of r293283 with a fixed comparison predicate as
std::merge requires a strict weak ordering.

Differential revision: https://reviews.llvm.org/D29327

llvm-svn: 293757
2017-02-01 10:26:03 +00:00
Rui Ueyama
f20ee9f11a Revert "[ELF][ARM] Use SyntheticSections for Thunks"
This reverts commit r293283 because it broke MSVC build.

llvm-svn: 293352
2017-01-28 00:48:06 +00:00
Peter Smith
5191c6f945 [ELF][ARM] Use SyntheticSections for Thunks
Thunks are now implemented by redirecting the relocation to the
symbol S, to a symbol TS in a Thunk. The Thunk will transfer control
to S. This has the following implications:
- All the side-effects of Thunks happen within createThunks()
- Thunks are no longer stored in InputSections and Symbols no longer
  need to hold a pointer to a Thunk
- The synthetic Thunk sections need to be merged into OutputSections
    
This implementation is almost a direct conversion of the existing
Thunks with the following exceptions:
- Mips LA25 Thunks are placed before the InputSection that defines
  the symbol that needs a Thunk.
- All ARM Thunks are placed at the end of the OutputSection of the
  first caller to the Thunk.
    
Range extension Thunks are not supported yet so it is optimistically
assumed that all Thunks can be reused.

Differential Revision:  https://reviews.llvm.org/D29129

llvm-svn: 293283
2017-01-27 13:10:16 +00:00
Rui Ueyama
c8d3a83fff Remove error(error_code, const Twine &).
Now we have the consistent interface for all log/warn/error/fatal functions.

llvm-svn: 291847
2017-01-12 22:18:04 +00:00
Rafael Espindola
79114a673e Make the -b binary .data section rw.
This matches what bfd and gold do. It also matches the common flags of
other .data sections.

llvm-svn: 291674
2017-01-11 15:13:05 +00:00
Peter Collingbourne
c39e5d64b3 ELF: Discard .gnu.linkonce.* sections.
The linkonce feature is a sort of proto-comdat. As far as I am aware no
compiler produces linkonce sections anymore, but some glibc i386 object
files contain definitions of symbol "__x86.get_pc_thunk.bx" in linkonce
sections. Drop those sections to avoid duplicate symbol errors.

This is glibc PR20543, we should remove this hack once that has been
fixed for a while.

Fixes PR31215.

Differential Revision: https://reviews.llvm.org/D28430

llvm-svn: 291474
2017-01-09 20:26:33 +00:00
Rui Ueyama
ec1c75e059 Add linker-script-included files to reproduce tar files.
Previously, files added using INCLUDE directive weren't added
to reproduce archives. In this patch, I defined a function to
open a file and use that from Driver and LinkerScript.

llvm-svn: 291413
2017-01-09 01:42:02 +00:00
Rafael Espindola
2756e04fac Handle versioned undefined symbols.
In order to keep symbol lookup a simple name lookup this patch adds
versioned symbols with an explicit @ to the symbol table.

llvm-svn: 291293
2017-01-06 22:30:35 +00:00
Rui Ueyama
ce039266c1 Merge elf::toString and coff::toString.
The two overloaded functions hid each other. This patch merges them.

llvm-svn: 291222
2017-01-06 10:04:08 +00:00
Rui Ueyama
214a897681 Use \ as the path separator on Windows.
Previously, when we printed out a path obtained from DWARF debug info,
we replaced \ with / on Windows. But that doesn't make sense. We should
respect the system's path separator.

llvm-svn: 291219
2017-01-06 08:59:32 +00:00
Rui Ueyama
7f1f912794 Use TarWriter to create tar archives instead of cpio.
This is how we use TarWriter in LLD. Now LLD does not append
a file extension, so you need to pass `--reproduce foo.tar`
instead of `--reproduce foo`.

Differential Revision: https://reviews.llvm.org/D28103

llvm-svn: 291210
2017-01-06 02:33:53 +00:00
Peter Smith
97c6d78f3e [ELF] Add support for thunks to undefined non-weak symbols
In a shared library an undefined symbol is implicitly imported. If the
symbol is called as a function a PLT entry is generated for it. When the
caller is a Thumb b.w a thunk to the PLT entry is needed as all PLT
entries are in ARM state.
    
This change allows undefined symbols to have thunks in the same way that
shared symbols may have thunks.

llvm-svn: 290951
2017-01-04 09:45:45 +00:00
Rui Ueyama
9381eb1045 Remove lld/Support/Memory.h.
I thought for a while about how to remove it, but it looks like we
can just copy the file for now. Of course I'm not happy about that,
but it's just less than 50 lines of code, and we already have
duplicate code in Error.h and some other places. I want to solve
them all at once later.

Differential Revision: https://reviews.llvm.org/D27819

llvm-svn: 290062
2016-12-18 14:06:06 +00:00
Peter Smith
532bc984f5 [ELF] Accept first SHT_ARM_ATTRIBUTES section
The eglibc library, as used by Ubuntu 14.04 requires the presence of an
SHT_ARM_ATTRIBUTES section in for the purposes of checking hard/soft float
compatibility when dlopen() is used. Unfortunately when the section is not
present dlopen() fails with a generic could not find file message.
    
This change makes lld keep the first .ARM.attributes section that it
encounters and propagates it to the output. This is not a complete
SHT_ARM_ATTRIBUTES implementation, that would involve reading the contents
of the section and joining each individual attribute. It should suffice
for a homogenous build all libraries and executables on the same system
with a compatible set of command line options.

Differential revision: https://reviews.llvm.org/D27718

llvm-svn: 289642
2016-12-14 10:36:12 +00:00
Rui Ueyama
520d9169e6 Move Memory.{h,cpp} to lld/Support so that we can use them from COFF.
llvm-svn: 289084
2016-12-08 18:31:13 +00:00
Rui Ueyama
9a97acc097 Remove redundant call of std::unique_ptr::get.
Obj is an instance of std::unique_ptr, so *Obj.get() is the same as *Obj.

llvm-svn: 288996
2016-12-07 23:26:39 +00:00
Rui Ueyama
f966fe6c38 Do not pass line number to convertToUnixPathSeparator.
Line number can never contain '/' or '\', so the previous code
was pointless at that point.

llvm-svn: 288973
2016-12-07 20:25:45 +00:00
Rui Ueyama
63d064e9d1 Make convertToUnixPathSeparator return a new string instead of mutating argument.
llvm-svn: 288972
2016-12-07 20:22:27 +00:00
George Rimar
49326e4d84 Format. NFC.
llvm-svn: 288967
2016-12-07 19:44:27 +00:00
George Rimar
92c88a4f76 [ELF] - Print absolute file name in errors when possible.
Currently LLD prints basename of source file name in error messages,
for example:
$ mkdir foo
$ echo 'void _start(void) { foobar(); }' > foo/bar.c
$ gcc -g -c foo/bar.c
$ bin/ld.lld -o out bar.o 
bin/ld.lld: error: bar.c:1: undefined symbol 'foobar'
$
This should say:
bin/ld.lld: error: foo/bar.c:1: undefined symbol 'foobar'

This is PR31299

Differential revision: https://reviews.llvm.org/D27506

llvm-svn: 288966
2016-12-07 19:42:25 +00:00
Rui Ueyama
84e65a7ca1 Use StringRefZ explicitly instead of const char *.
This patch is to avoid an implicit conversion from const char * to
StringRefZ, to make it apparent where we are using StringRefZ.

llvm-svn: 288182
2016-11-29 19:11:39 +00:00
Rui Ueyama
a13efc2a73 Introduce StringRefZ class to represent null-terminated strings.
StringRefZ is a class to represent a null-terminated string. String
length is computed lazily, so it's more efficient than StringRef to
represent strings in string table.

The motivation of defining this new class is to merge functions
that only differ in string types; we have many constructors that takes
`const char *` or `StringRef`. With StringRefZ, we can merge them.

Differential Revision: https://reviews.llvm.org/D27037

llvm-svn: 288172
2016-11-29 18:05:04 +00:00
Rui Ueyama
623b36e358 Move typedefs inside a class definition.
llvm-svn: 287945
2016-11-25 18:51:56 +00:00
Rui Ueyama
3fc0f7e54f Define toString() as a generic function to get a string for error message.
We have different functions to stringize objects to construct
error messages. For InputFile, we have getFilename, and for
InputSection, we have getName. You had to memorize them.

I think this is the case where the function overloading comes in handy.

This patch defines toString() functions that are overloaded for all these
types, so that you just call it in error().

Differential Revision: https://reviews.llvm.org/D27030

llvm-svn: 287787
2016-11-23 18:07:33 +00:00
Eugene Leviant
c3a44b2fbe [ELF] Refactor several error messages
Differential revision: https://reviews.llvm.org/D26970

llvm-svn: 287753
2016-11-23 10:07:46 +00:00
Rui Ueyama
0cbf749397 Remove one of SymbolTable::addRegular function that forwards other addRegular.
So that we have less number of overloaded functions.

llvm-svn: 287745
2016-11-23 06:59:47 +00:00
Rui Ueyama
c72ba3a4d7 Allow calling getName() on local symbols.
Previously, we stored offsets in string tables to symbols, so
you needed to pass a string table to get a symbol name. This patch
stores const char pointers instead to eliminate the need to pass
a string table.

llvm-svn: 287737
2016-11-23 04:57:25 +00:00
Rui Ueyama
e8785ba4d7 Change the way how we print out line numbers.
LLD's error messages contain line numbers, function names or section names.
Currently they are formatter as follows.

  foo.c (32): symbol 'foo' not found
  foo.c (function bar): symbol 'foo' not found
  foo.c (.text+0x1234): symbol 'foo' not found

This patch changes them so that they are consistent with Clang's output.

  foo.c:32: symbol 'foo' not found
  foo.c:(function bar): symbol 'foo' not found
  foo.c:(.text+0x1234): symbol 'foo' not found

Differential Revision: https://reviews.llvm.org/D26901

llvm-svn: 287537
2016-11-21 13:49:57 +00:00
Eugene Leviant
7d7ff80f4b [ELF] Better error reporting for broken archives
Differential revision: https://reviews.llvm.org/D26852

llvm-svn: 287527
2016-11-21 09:28:07 +00:00
George Rimar
463984d4bf [ELF] - Better diagnostic for relative relocation to an absolute value error.
Patch adds a filename to that error message.

I faced next error when debugged one of FreeBSD port:
error: relocation R_X86_64_PLT32 cannot refer to absolute symbol __tls_get_addr

error message was poor and this patch improves it to show the locations 
of symbol declaration and using.

Differential revision: https://reviews.llvm.org/D26508

llvm-svn: 286940
2016-11-15 08:07:14 +00:00
George Rimar
308752e474 [ELF] - Allow symbols of STT_NOTYPE to be associated with SHT_SYMTAB sections.
Found this when tried to link lang/ccl FreeBSD port.
Issue is very close to D23201.
This is the reason of lang/ccl port link fail.

GNU assembler 2.17.50 [FreeBSD] 2007-07-03 could generate broken objects,
where notype symbols are associated with symtab:
...
[ 9] .symtab           SYMTAB           0000000000000000  00003c78
     0000000000006858  0000000000000018          10   803     8
...
192: 000000000000000d     0 NOTYPE  LOCAL  DEFAULT    9 _cons_org

Patch allows to handle such objects.

Differential revision: https://reviews.llvm.org/D26613

llvm-svn: 286939
2016-11-15 07:56:28 +00:00
George Rimar
0b2d374c01 [ELF] - format. NFC.
llvm-svn: 286804
2016-11-14 10:05:53 +00:00
Peter Collingbourne
cd513a41c1 Bitcode: Clean up error handling for certain bitcode query functions.
The functions getBitcodeTargetTriple(), isBitcodeContainingObjCCategory(),
getBitcodeProducerString() and hasGlobalValueSummary() now return errors
via their return value rather than via the diagnostic handler.

To make this work, re-implement these functions using non-member functions
so that they can be used without the LLVMContext required by BitcodeReader.

Differential Revision: https://reviews.llvm.org/D26532

llvm-svn: 286623
2016-11-11 19:50:24 +00:00
Teresa Johnson
1e390897ba Mirror the llvm changes that split Bitcode/ReaderWriter.h
The change in D26502 splits ReaderWriter.h, which contains the APIs
into both the BitReader and BitWriter libraries, into BitcodeReader.h
and BitcodeWriter.h.

Change lld uses to the appropriate split header, removing it
completely in one case where it wasn't needed.

llvm-svn: 286568
2016-11-11 05:35:22 +00:00
Rafael Espindola
9f0c4bb795 Parse relocations only once.
Relocations are the last thing that we wore storing a raw section
pointer to and parsing on demand.

With this patch we parse it only once and store a pointer to the
actual data.

The patch also changes where we store it. It is now in
InputSectionBase. Not all sections have relocations, but most do and
this simplifies the logic. It also means that we now only support one
relocation section per section. Given that that constraint is
maintained even with -r with gold bfd and lld, I think it is OK.

llvm-svn: 286459
2016-11-10 14:53:24 +00:00
Rui Ueyama
1bdaf3e30c Remove an overloaded function to simplify.
This version of addRegular is almost identical to the other except
it lacked "size" parameter.

llvm-svn: 286416
2016-11-09 23:37:40 +00:00
Simon Atanasyan
fa03b0fafa [ELF][MIPS] Convert .MIPS.abiflags section to synthetic input section
Previously, we have both input and output section for .MIPS.abiflags.
Now we have only one class for .MIPS.abiflags, which is MipsAbiFlagsSection.
This class is a synthetic input section.

.MIPS.abiflags sections are handled as regular sections until
the control reaches Writer. Writer then aggregates all sections
whose type is SHT_MIPS_ABIFLAGS to create a single synthesized
input section. The synthesized section is then processed normally
as if it came from an input file.

llvm-svn: 286398
2016-11-09 21:37:06 +00:00
Simon Atanasyan
ce02cf0099 [ELF][MIPS] Convert .reginfo and .MIPS.options sections to synthetic input sections
Previously, we have both input and output sections for .reginfo and
.MIPS.options. Now for each such sections we have one synthetic input
sections: MipsReginfoSection and MipsOptionsSection respectively.

Both sections are handled as regular sections until the control reaches
Writer. Writer then aggregates all sections whose type is SHT_MIPS_REGINFO
or SHT_MIPS_OPTIONS to create a single synthesized input section. In that
moment Writer also save GP0 value to the MipsGp0 field of the corresponding
ObjectFile. This value required for R_MIPS_GPREL16 and R_MIPS_GPREL32
relocations calculation.

Differential revision: https://reviews.llvm.org/D26444

llvm-svn: 286397
2016-11-09 21:36:56 +00:00
Rafael Espindola
6ff570a395 Make Discarded a InputSection.
It was quite confusing that it had SectionKind of Regular, but was not
actually a InputSection.

llvm-svn: 286379
2016-11-09 16:55:07 +00:00
Rafael Espindola
73c3a36b9f Remove dead arguments. NFC.
llvm-svn: 286242
2016-11-08 15:51:00 +00:00
Davide Italiano
ba8761bc7f [LTO] Don't leak BitcodeFiles. Found by the asan bot.
llvm-svn: 286194
2016-11-08 01:46:02 +00:00
Davide Italiano
089f0e7488 [ELF] Don't leak the ".data" section. Fixes an asan failure.
llvm-svn: 286193
2016-11-08 01:42:38 +00:00
Rafael Espindola
8e232573a8 Simplify now that this is only used for global symbols.
llvm-svn: 285966
2016-11-03 20:48:57 +00:00
Rafael Espindola
e19abab9a7 Now that the ELFFile constructor does nothing, create it when needed.
This avoids duplicating the buffer in InputFile.

llvm-svn: 285965
2016-11-03 20:44:50 +00:00
Rafael Espindola
22e9a8e366 Update for llvm change.
llvm-svn: 285962
2016-11-03 20:17:25 +00:00
Rui Ueyama
271194016a Simplify by directly using this->Symbols. NFC.
llvm-svn: 285952
2016-11-03 18:20:08 +00:00
Rafael Espindola
6dcf4c6859 Change how we store the symbol table.
Instead of remembering a raw Elf_Shdr, store the symbol table proper
and the index of the first non local.

This moves error handling upfront and simplifies it.

llvm-svn: 285933
2016-11-03 16:55:44 +00:00
Rafael Espindola
21d8be9a4e Initialize the StringTable early and do it only once.
llvm-svn: 285926
2016-11-03 15:43:47 +00:00
Rafael Espindola
73aba6229f Use the getSectionIndex from llvm.
llvm-svn: 285918
2016-11-03 14:26:25 +00:00
Rafael Espindola
cc728b41b6 Use existing ELFObj function. NFC.
llvm-svn: 285913
2016-11-03 14:17:53 +00:00
Rafael Espindola
382200abb7 Update for llvm change.
llvm-svn: 285911
2016-11-03 13:58:26 +00:00
Rafael Espindola
dd6abaad75 Update for llvm change.
llvm-svn: 285906
2016-11-03 13:43:51 +00:00
Rafael Espindola
6d18d388c5 Pass the section table around instead of recomputing it.
llvm-svn: 285904
2016-11-03 13:24:29 +00:00
Rafael Espindola
84d6a17134 We already have the sections, pass them to getSHNDXTable.
llvm-svn: 285897
2016-11-03 12:21:00 +00:00
George Rimar
4d2aad9da6 [ELF] - Update after LLVM change (r285886)
llvm-svn: 285888
2016-11-03 08:42:52 +00:00
Rafael Espindola
7c7abafd81 Pass the sections to getShtGroupSignature.
This avoids fetching it again from the object.

llvm-svn: 285875
2016-11-03 02:28:13 +00:00
Rui Ueyama
7463adadbf Fix Windows buildbot.
llvm-svn: 285854
2016-11-02 19:51:41 +00:00
Rui Ueyama
7556f6b276 Reduce number of classes by merging DIHelper with ObjectFile.
DIHelper is a class having only one member, and ObjectFile has
a unique pointer to a DIHelper. So we can directly have ObjectFile
have the member.

Differential Revision: https://reviews.llvm.org/D26223

llvm-svn: 285850
2016-11-02 18:42:13 +00:00
Rafael Espindola
199e00408f Pass the section table to getSectionStringTable. NFC.
This will let us simplify the llvm side.

llvm-svn: 285816
2016-11-02 15:21:24 +00:00
Rafael Espindola
235d82cd0a Don't use getNumSections.
It is just the size of sections() which we were already calling.

llvm-svn: 285811
2016-11-02 14:42:20 +00:00
Rafael Espindola
390aaca662 Update for llvm change.
llvm-svn: 285808
2016-11-02 14:11:05 +00:00
Rafael Espindola
c17e0b6f68 Simplify SHF_LINK_ORDER handling. NFC.
While ARM is the only currently user we support this is a general
feature.

This avoids a second walk over the sections.

llvm-svn: 285805
2016-11-02 13:36:31 +00:00
George Rimar
bcba39ab9c [ELF] - Check that .dynsym is present in DSO if SHT_GNU_versym section is.
When we have SHT_GNU_versym section, it is should be associated with symbol table
section. Usually (and in out implementation) it is .dynsym.
In case when .dynsym is absent (due to broken object for example), 
lld crashes in parseVerdefs() when accesses null pointer:

Versym = reinterpret_cast<const Elf_Versym *>(this->ELFObj.base() +
                                              VersymSec->sh_offset) +
         this->Symtab->sh_info;

DIfferential revision: https://reviews.llvm.org/D25553

llvm-svn: 285796
2016-11-02 10:16:25 +00:00
Rui Ueyama
d52adb3917 Provide a convenient function to allocate and initialize objects.
You can now write make<T>(Args) instead of new (alloc<T>()) T(Args).

llvm-svn: 285760
2016-11-01 22:53:18 +00:00
Rafael Espindola
ec05a574fe Don't fetch the section string table multiple times. NFC.
llvm-svn: 285755
2016-11-01 21:48:00 +00:00
Rafael Espindola
5c9e8f5e52 Replace GAlloc with a template function.
This patch replaces GAlloc<ELFT>::<sometype>.Allocate() with
alloc<sometype<ELFT>>().

Patch by Rui!

llvm-svn: 285748
2016-11-01 21:06:40 +00:00
Eugene Leviant
c4681203e1 Allow fetching source line, when multiple "AX" sections present
Differential revision: https://reviews.llvm.org/D26070

llvm-svn: 285680
2016-11-01 09:17:50 +00:00
Rui Ueyama
55518e7dd8 Consolidate BumpPtrAllocators.
Previously, we have a lot of BumpPtrAllocators, but all these
allocators virtually have the same lifetime because they are
not freed until the linker finishes its job. This patch aggregates
them into a single allocator.

Differential revision: https://reviews.llvm.org/D26042

llvm-svn: 285452
2016-10-28 20:57:25 +00:00
Rui Ueyama
44fa48f986 Define ~DIHelper::DIHelper() in .cpp.
llvm-svn: 285347
2016-10-27 21:26:57 +00:00
Rafael Espindola
093abab817 Don't create a dummy ELF to process a binary file.
Now that it is easy to create input section and symbols, this is
simple.

llvm-svn: 285322
2016-10-27 17:45:40 +00:00
Rafael Espindola
7cc713adcb Store OSABI in Config.
This allows us to set a value for it based on -m.

llvm-svn: 285294
2016-10-27 14:00:51 +00:00
Rafael Espindola
a8631e3887 Use fewer allocators.
Instead of having 3 section allocators per file, have 3 for all files.

This is a substantial performance improvement for some cases. Linking
chromium without gc speeds up by 1.065x.

This requires using _exit in fatal since we have to avoid destructing
an InputSection if fatal is called from the constructor.

Thanks to Rui for the suggestion.

llvm-svn: 285290
2016-10-27 13:32:32 +00:00
Rafael Espindola
5da1d88492 Reduce the number of allocators.
We used to have one allocator per file, which reduces the advantage of
using an allocator in the first place.

This is a small speed up is most cases. The largest speedup was in
1.014X in chromium no-gc. The largest slowdown was scylla at 1.003X.

llvm-svn: 285205
2016-10-26 15:34:24 +00:00
Eugene Leviant
b380b24e6e [ELF] Better error reporting for undefined symbols
This patch make lld show following details for undefined symbol errors:
- file (line)
- file (function name)
- file (section name + offset)

Differential revision: https://reviews.llvm.org/D25826

llvm-svn: 285186
2016-10-26 11:07:09 +00:00
Rafael Espindola
3db70210f8 Update for llvm change.
llvm-svn: 285062
2016-10-25 12:02:31 +00:00
Rafael Espindola
8b2c8536e5 Use a CachedHashString for comdats too.
We were already using it in the larger sets/maps. This provides about
1% speedup in linking xul and chromium.

llvm-svn: 284862
2016-10-21 19:49:42 +00:00
Rui Ueyama
617d587432 Move code from InputFile to ELFCreator to decouple the two files.
Now that only one non-member function is exported from ELFCreator.h.
All the details are handled internally in ELFCreator.cpp file.

llvm-svn: 284786
2016-10-20 21:57:06 +00:00
George Rimar
a4c7e74d4b [ELF] - Applied clang format. NFC.
llvm-svn: 284705
2016-10-20 08:36:42 +00:00
Rui Ueyama
673c9d9018 Add a helper function to define symbols.
Also replace std::copy with memcpy because in other places we are
using memcpy.

llvm-svn: 284700
2016-10-20 06:44:58 +00:00
Rui Ueyama
f2e78818e8 Rename variables so that they are more in line with rest of the code.
llvm-svn: 284699
2016-10-20 06:34:03 +00:00
Rui Ueyama
837182ec1e Remove std:: from std::size_t.
llvm-svn: 284687
2016-10-20 01:33:09 +00:00
Rafael Espindola
00ee5edc0d Avoid using getComdatSymbolTable.
This is not particularly efficient, but does avoid exposing Comdat*
out of LTO.h.

I will send a patch for review with a more efficient interface that
should map nicely to a bitcode symbol table.

llvm-svn: 284413
2016-10-17 19:25:08 +00:00
Rafael Espindola
b18783e441 Update for llvm change.
llvm-svn: 284409
2016-10-17 18:51:27 +00:00
George Rimar
17d566daaa [ELF] - Don't crash on multiple SHT_MIPS_REGINFO/SHT_MIPS_ABIFLAGS sections.
In continue of D25555, this patch fixes possible crash when
we have multiple SHT_MIPS_REGINFO or SHT_MIPS_ABIFLAGS sections.
yaml2obj was used to produce such objects.

Differential revision: https://reviews.llvm.org/D25609

llvm-svn: 284376
2016-10-17 11:31:46 +00:00
George Rimar
85e6106d76 [ELF] - Do not crash when object has multiple SHT_MIPS_OPTIONS
Issue was revealed by AFl and I was able to generate such object using yaml2obj.

When object has more than one SHT_MIPS_OPTIONS, 
each except the last one is destroyed after placing into Sections array.
Sections array contains dead pointers finally. LLD may crash then.

Differential revision: https://reviews.llvm.org/D25555

llvm-svn: 284227
2016-10-14 11:10:36 +00:00
Davide Italiano
bcdd6c60a0 [ThinLTO] Avoid archive member collisions.
This fixes PR30665.

Differential Revision:  https://reviews.llvm.org/D25495

llvm-svn: 284034
2016-10-12 19:35:54 +00:00
George Rimar
27e651d4f6 Recommit r283733 "[ELF] - Do not crash if common symbol alignment set to value greater than UINT32_MAX.
With fix: commit changes from InputFiles.cpp too.

Original commit message:
We have following code in lld, that truncates the alignment value to 32 bit. Big alignment in this case
may give result 0 and crash later.

template <class ELFT>
CommonInputSection<ELFT>::CommonInputSection(std::vector<DefinedCommon *> Syms)
    : InputSection<ELFT>(nullptr, &Hdr, "") {
....
  for (DefinedCommon *Sym : Syms) {
    this->Alignment = std::max<uintX_t>(this->Alignment, Sym->Alignment);
...
  }
}

Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D25235

llvm-svn: 283738
2016-10-10 10:31:03 +00:00
Peter Smith
bafd3c40e2 [ELF][ARM] Fix formatting mistake, removed extra space before ) NFC.
llvm-svn: 283735
2016-10-10 10:18:58 +00:00
Peter Smith
0760605ac5 [ELF][ARM] Garbage collection support for .ARM.exidx sections
.ARM.exidx sections have a reverse dependency on the section they have
a SHF_LINK_ORDER dependency on. In other words a .ARM.exidx section is
live only if the executable section it describes is live. We implement
this with a reverse dependency field in InputSection.

Adding the dependency to InputSection is the simplest implementation
but it could be moved out to a separate map if it were found to decrease
performance for non ARM targets.

Differential revision: https://reviews.llvm.org/D25234

llvm-svn: 283734
2016-10-10 10:10:27 +00:00
George Rimar
9397cf953c [ELF] - Fixed assert fail when symbol table has zero sh_info value.
When sh_info of sumbol table value was set to zero, lld was asserting.

Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D25016

llvm-svn: 283562
2016-10-07 15:16:27 +00:00
George Rimar
53cf2a8112 [ELF] - Do not crash on invalid size of dynamic section.
Previously if sh_size of dynamic section was broken,
lld may crash. Or even may not crash if used 32 bits host.
(then value may be truncated to 32 bits when doing pointer arithmetic 
and could be just zero).
Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D25327

llvm-svn: 283533
2016-10-07 09:01:04 +00:00
George Rimar
b7aec33125 [ELF] - Do not crash when unable to parse ELF object file.
createELFObj() may call error(...), for example when file is too short.
In that case header is not set and following line lead to crash:

EMachine = ELFObj.getHeader()->e_machine;

Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D25233

llvm-svn: 283532
2016-10-07 08:51:57 +00:00
George Rimar
24adce95b2 [ELF] - Make checks in ObjectFile<ELFT>::getSection() stricter.
This patch makes the check for null section stricter, 
so it is only allowed for STT_SECTION symbols now.

Differential revision: https://reviews.llvm.org/D25231

llvm-svn: 283426
2016-10-06 09:17:55 +00:00
Simon Atanasyan
02b9c3f8c3 [ELF] Do not merge sections in case of relocatable object generation
Do not merge sections if generating a relocatable object. It makes
the code simpler because we do not need to update relocations addends
to reflect changes introduced by merging. Instead of that we write
such "merge" sections into separate OutputSections and keep SHF_MERGE
/ SHF_STRINGS flags and sh_entsize value to be able to perform merging
later during a final linking.

Differential Revision: http://reviews.llvm.org/D25066

llvm-svn: 283300
2016-10-05 07:49:18 +00:00
Rui Ueyama
af9793d1c1 Add a comment.
llvm-svn: 283229
2016-10-04 16:47:49 +00:00
Eugene Leviant
b90f3cf15b [ELF] Don't discard excluded section if -r is used
This conforms to GNU ld/gold behavior and fixes crash in case
excluded section also has associated relocation section

llvm-svn: 283214
2016-10-04 12:05:42 +00:00
George Rimar
0c82561c4c [ELF] - Do not crash if common symbol has alignment 0.
Testcase contains a common symbol with zero alignment,
previously lld would crash, patch fixes that.

Differential revision: https://reviews.llvm.org/D25085

llvm-svn: 283197
2016-10-04 08:49:52 +00:00
George Rimar
10874f70fa [ELF] - Apply clang-format. NFC.
llvm-svn: 283101
2016-10-03 11:13:55 +00:00
Rui Ueyama
eb0007aa0c Remove an warning message that can be spammy.
This was intended to warn on a usage error of an ar command.
I was thinking that false positive would be rare because it
has two guards: it warns only when an archive file has no symbols
and contains at least one file.

Turned out that false positive would probably be not that rare.
You wouldn't intentionally create an object file that contains no
exported symbols, but with conditional compile guards, you could
create such file. If it is for a LTO build, you could create an
archive file containing such file. That means there's no way to
detect the usage error in a reliable manner.

This patch simply removes the warning.

llvm-svn: 282916
2016-09-30 19:59:25 +00:00
Rui Ueyama
3d0f77b281 Improve error check for an empty archive.
Previously, it warned on any archive file that has no symbol.
It turned out that that is too noisy.

With this patch, it warns on such archive file that contains no file.

Differential Revision: https://reviews.llvm.org/D25111

llvm-svn: 282885
2016-09-30 17:56:20 +00:00
Rui Ueyama
e364d1f431 Add comments.
llvm-svn: 282807
2016-09-29 23:04:50 +00:00
Rui Ueyama
d31e13f287 Rename warning -> warn.
It's better because it's a verb.

llvm-svn: 282763
2016-09-29 21:00:23 +00:00
Rui Ueyama
d72dd1fc4e Use InputFile::Symbol instead of auto for consistency.
llvm-svn: 282658
2016-09-29 00:58:10 +00:00
Davide Italiano
786d8e33db [ELF/LTO] Switch to the new resolution-based API.
Differential Revision:  https://reviews.llvm.org/D24492

llvm-svn: 282656
2016-09-29 00:40:08 +00:00
Rui Ueyama
cb85d7f840 Warn on empty archive files.
Differential Revision: https://reviews.llvm.org/D25044

llvm-svn: 282633
2016-09-28 21:10:54 +00:00
Rafael Espindola
5217f8452c Sort headers. NFC.
llvm-svn: 282603
2016-09-28 16:31:05 +00:00
Eugene Leviant
27be542cdf [ELF] Ignore sections flagged with SHF_EXCLUDE
Differential revision: https://reviews.llvm.org/D24966

llvm-svn: 282568
2016-09-28 08:42:02 +00:00
Rui Ueyama
c75ef85e84 Accept sh_entsize = 0.
This surfaced again with Rust. As per bug 30435, rustc creates a
mergeable section with a sh_entsize zero. It bit us before, too.
I think we should relax the input check rather than being too picky.

Differential Revision: https://reviews.llvm.org/D24789

llvm-svn: 282049
2016-09-21 03:22:18 +00:00
Rui Ueyama
38dbd3eea9 Simplify InputFile ownership management.
Previously, all input files were owned by the symbol table.
Files were created at various places, such as the Driver, the lazy
symbols, or the bitcode compiler, and the ownership of new files
was transferred to the symbol table using std::unique_ptr.
All input files were then free'd when the symbol table is freed
which is on program exit.

I think we don't have to transfer ownership just to free all
instance at once on exit.

In this patch, all instances are automatically collected to a
vector and freed on exit. In this way, we no longer have to
use std::unique_ptr.

Differential Revision: https://reviews.llvm.org/D24493

llvm-svn: 281425
2016-09-14 00:05:51 +00:00
Rafael Espindola
10897f1807 Enable merging of SHF_MERGE sections with linker scripts.
This also fixes the related problem of non SHF_MERGE sections with
different flags not being merged.

Fixes pr30355.

llvm-svn: 281338
2016-09-13 14:23:14 +00:00
Rui Ueyama
0eb2a1bd7a Add comments.
llvm-svn: 281265
2016-09-12 21:44:29 +00:00
Michael J. Spencer
a9424f39c4 [ELF] Add support for -b binary
Implemented by building an ELF file in memory.

elf, default, and binary match gold behavior.

Differential Revision: https://reviews.llvm.org/D24060

llvm-svn: 281108
2016-09-09 22:08:04 +00:00
Rui Ueyama
478f8eb6ef Add comments.
llvm-svn: 281098
2016-09-09 21:35:38 +00:00
Davide Italiano
e02ba98f8f [ELF] Fix DT_NEEDED value.
Differential Revision: https://reviews.llvm.org/D24363

llvm-svn: 280990
2016-09-08 21:18:38 +00:00
Rafael Espindola
042a3f209b Compute section names only once.
This simplifies error handling as there is now only one place in the
code that needs to consider the possibility that the name is
corrupted. Before we would do it in every access.

llvm-svn: 280937
2016-09-08 14:06:08 +00:00
Davide Italiano
29fa6ab7b1 [LTO/InputFiles] Merge two ifs into one. NFCI.
llvm-svn: 280225
2016-08-31 12:27:47 +00:00
George Rimar
f21aade0d8 [ELF] - Introduce StripPolicy instead of Config->StripAll/StripDebug flags.
This approach is not only consistent with UnresolvedPolicy, 
but also should help to solve a problem 
of options with opposing meanings, mentioned in PR28843

Differential revision: https://reviews.llvm.org/D23869

llvm-svn: 280206
2016-08-31 08:38:11 +00:00
Rafael Espindola
cceb92a075 Pass Binding instead of IsWeak to addBitcode.
We were computing the binding on both the caller and callee.

llvm-svn: 280156
2016-08-30 20:53:26 +00:00
Davide Italiano
35af5b3d21 [LTO] Fix the logic for dropping unnamed_addr.
Differential Revision:  https://reviews.llvm.org/D24037

llvm-svn: 280144
2016-08-30 20:15:03 +00:00
George Rimar
67e3ff83f5 [ELF] - Do not use mergeable sections when LS is used.
After latest changes we combine input sections with 
different attributes into single output section. 
Problem here is that regular output sections does not
support adding mergeable input sections (and vise versa).
Patch just temporarily disables merging for now at 
the same way we do for -O0 for example.

This change helps for linking FreeBSD kernel.

Differential revision: https://reviews.llvm.org/D23447

llvm-svn: 278555
2016-08-12 19:56:57 +00:00
George Rimar
683a35d066 [ELF] - Fix for: error "invalid section index: xxx" when linking FreeBSD kernel.
We found that GNU assembler 2.17.50 [FreeBSD] 2007-07-03
could generate broken objects. STT_SECTION symbols can be
associated with SHT_REL[A]/SHT_SYMTAB/SHT_STRTAB sections.

This is PR28868, patch fixes handling of such files.

Differential revision: https://reviews.llvm.org/D23201

llvm-svn: 278550
2016-08-12 19:25:54 +00:00
Simon Atanasyan
85c6b44817 [ELF][MIPS] Support .MIPS.abiflags section
This section supersedes .reginfo and .MIPS.options sections. But for now
we have to support all three sections for ABI transition period.

llvm-svn: 278482
2016-08-12 06:28:49 +00:00
Rui Ueyama
803568866c Rename functions that handle bitcode files.
getELFKind was overloaded with bitcode files and regular object files,
and I found that is a bit confusing. This patch renames them.

llvm-svn: 277646
2016-08-03 20:33:17 +00:00
Rui Ueyama
7fdb4389a2 Do not instantiate Triple twice.
Also removes redundant variables. NFC.

llvm-svn: 277644
2016-08-03 20:25:29 +00:00
Rui Ueyama
6c50990df6 Add EM_IAMCU support.
This patch adds "-m elf_iamcu" to ldd for IAMCU psABI:
https://github.com/hjl-tools/x86-psABI/wiki/X86-psABI

Patch by H.J Lu.

llvm-svn: 277643
2016-08-03 20:15:56 +00:00
Rui Ueyama
3ebc71eb91 Do not handle zero-sized mergeable section as mergeable.
Mergeable sections with size zero are useless because they don't
actually contain data, and therefore there's no merit ot merge them.
However, in reality, there are object files in the wild containing
such sections. Currently, LLD can't handle them proerply.

This patch makes LLD to handle such sections as if they are non-
mergeable to fix the issue.

Fixes bug 28822.

llvm-svn: 277568
2016-08-03 05:28:02 +00:00
Rui Ueyama
3b452a7a22 Move code for MIPS from createInputSection to initializeSections.
We already have code for ARM in initializeSections, so this
is more consistent.

Differential Revision: https://reviews.llvm.org/D22833

llvm-svn: 276811
2016-07-26 21:26:02 +00:00
Simon Atanasyan
72170d2753 [ELF][MIPS] Use section type to recognize .reginfo and .MIPS.options sections
It is faster and more correct method than string comparision.

llvm-svn: 276807
2016-07-26 21:11:26 +00:00
Rui Ueyama
69c778c084 Implement almost-zero-cost --trace-symbol.
--trace-symbol is a command line option to watch a symbol.
Previosly, we looked up a hash table for a new symbol if the
option is given. Any code that looks up a hash table for each
symbol is expensive because the linker handles a lot of symbols.
In our design, we look up a hash table strictly only once
for a symbol, so --trace-symbol was an exception.

This patch improves efficiency of the option by merging the
hash table into the symbol table.

Instead of looking up a separate hash table with a string,
this patch sets `Traced` flag to symbols specified by --trace-symbol.
So, if you insert a symbol and get a symbol with `Traced` flag on,
you know that you need to print out a log message for the symbol.
This is nearly zero cost.

llvm-svn: 275716
2016-07-17 17:50:09 +00:00
Rui Ueyama
434b56179e Add a pointer to a source file to SymbolBody.
Previously, each subclass of SymbolBody had a pointer to a source
file from which it was created. So, there was no single way to get
a source file for a symbol. We had getSourceFile<ELFT>(), but the
function was a bit inconvenient as it's a template.

This patch makes SymbolBody have a pointer to a source file.
If a symbol is not created from a file, the pointer has a nullptr.

llvm-svn: 275701
2016-07-17 03:11:46 +00:00
Rui Ueyama
818bb2f8dc Remove redundant namespace specifiers.
llvm-svn: 275694
2016-07-16 18:55:47 +00:00
Rui Ueyama
429ef2af6a ELF: Include filenames in error messages.
llvm-svn: 275608
2016-07-15 20:38:28 +00:00
Rui Ueyama
188d2c34e6 Remove variables. NFC.
llvm-svn: 275605
2016-07-15 20:05:05 +00:00
Rui Ueyama
3d9b26b4ad Inline traceUndefined function.
llvm-svn: 275531
2016-07-15 04:57:46 +00:00
Rui Ueyama
eba9b63cbc Update comments.
llvm-svn: 275530
2016-07-15 04:57:44 +00:00
Rui Ueyama
f8292e9ac9 ELF: Make check() always return a value.
This patch corresponds to r275511 for COFF.

llvm-svn: 275521
2016-07-15 02:01:03 +00:00
Rui Ueyama
8b8d0055fe Fix memory leak.
Symbol's dtors are not called because they are allocated using
BumpPtrAllocators. So, members of std::unique_ptr type are not
freed when symbols are deallocated.

This patch is to allocate Thunks using BumpPtrAllocators.

llvm-svn: 274896
2016-07-08 17:58:54 +00:00
Rui Ueyama
523744dd2b Fix formatting.
llvm-svn: 274724
2016-07-07 02:46:30 +00:00
Rui Ueyama
d573844a1f Fix formatting. NFC.
llvm-svn: 274426
2016-07-02 06:08:44 +00:00
Davide Italiano
e929f424a4 [BitcodeFile] Simplify shouldSkip(). NFCI.
llvm-svn: 274383
2016-07-01 20:43:28 +00:00
Davide Italiano
e3fa8f64da [ELF] More self-explanatory error message when e_machine can't be inferred.
Thanks to Sean Silva for the suggestion!

llvm-svn: 274134
2016-06-29 15:58:37 +00:00
Davide Italiano
60976ba86d [LTO] Infer ELFKind/EMachine from Bitcode files
So that users are not forced to pass `-m` on the command line
when the inputs are all bitcode.

PR:   28268
Differential Revision:  http://reviews.llvm.org/D21779

llvm-svn: 274107
2016-06-29 06:12:39 +00:00
Rui Ueyama
5e64d3fb94 Refactor ELF type inference functions.
Previously, we initialized Config->EKind and Config->EMachine when
we instantiate ELF objects. That was not an ideal location to do that
because the logic was buried too deep inside a concrete logic.

This patch moves the code to the driver so that the initialization
becomes explicit.

Differential Revision: http://reviews.llvm.org/D21784

llvm-svn: 274089
2016-06-29 01:30:50 +00:00
Rui Ueyama
d60dae8a6a Implement --trace-symbol=symbol option.
Patch by Shridhar Joshi.

This option provides names of all the link time modules which define and
reference symbols requested by user. This helps to speed up application
development by detecting references causing undefined symbols.
It also helps in detecting symbols being resolved to wrong (unintended)
definitions in case of applications containing multiple definitions for
same symbols with different types, bindings.

Implements PR28226.

llvm-svn: 273536
2016-06-23 07:00:17 +00:00
Rafael Espindola
cc70da39ff Internalize symbols in comdats.
We were dropping the CanOmitFromDynSym bit when creating undefined
symbols because of comdat.

llvm-svn: 272812
2016-06-15 17:56:10 +00:00
Rafael Espindola
65c65ce897 Don't include --start-lib/--end-lib files twice.
This should never happen with correct programs, but it is trivial
write a testcase where lld would crash or report duplicated
symbols. We now behave like when an archive is used and include the
file only once.

llvm-svn: 272724
2016-06-14 21:56:36 +00:00
Rafael Espindola
d2454d66e3 Fix global version handling.
We should not ignore the symbol, just the version.

Fixes error with -z defs.

llvm-svn: 272270
2016-06-09 15:45:49 +00:00
George Rimar
dcddfb63cd [ELF] Simplify shouldMerge() result calculation. NFC.
llvm-svn: 272131
2016-06-08 12:04:59 +00:00
George Rimar
d50a1459e9 [ELF] - Replaced hardcode with named constants. NFC.
llvm-svn: 272129
2016-06-08 11:40:24 +00:00
Peter Smith
8646ced053 Initial support for ARM in lld.
Add support for an ARM Target and the initial set of relocations
    and PLT entries that are necessary for an ARM only hello world to
    link. This has been tested against an ARM only sysroot from the
    4.2.0 CodeSourcery Lite release.
    
    Tests have been added to test/ELF for the support that has been
    implemented.
    
    Main limitations:
    - No Thumb support
    - Relocations incomplete
    - No C++ exceptions support
    - No TLS support
    - No range extension or interworking veneer (thunk) support
    - No Build Attribute support
    - No Big-endian support
    
    The deprecated relocations R_ARM_PLT32 and R_ARM_PC24 have been
    implemented as these are used by the 4.2.0 CodeSourcery Lite release.

llvm-svn: 271993
2016-06-07 09:31:52 +00:00
Rafael Espindola
acad605df9 Ignore the "globally available" version.
Reduced from a firefox build.

llvm-svn: 271950
2016-06-06 22:42:57 +00:00
Rui Ueyama
0b9a90364b Rename EHInputSection -> EhInputSection.
llvm-svn: 270532
2016-05-24 04:19:20 +00:00
Rui Ueyama
151ff30783 Simplify. NFC.
llvm-svn: 270531
2016-05-24 04:12:52 +00:00
Peter Smith
4df2e14dce Fix typo in comment aligment should be alignment. NFC.
llvm-svn: 269905
2016-05-18 11:40:16 +00:00
Rui Ueyama
fe65877c76 Reorganize the cpio archiver as CpioFile class. NFC.
This code separates the code to create cpio archive from the driver.

llvm-svn: 269593
2016-05-15 17:10:23 +00:00
Rafael Espindola
78db5a9dca Print member name in undefined symbol error.
llvm-svn: 268976
2016-05-09 21:40:06 +00:00
Simon Atanasyan
add74f37f2 [ELF][MIPS] Read/write .MIPS.options section
MIPS N64 ABI introduces .MIPS.options section which specifies miscellaneous
options to be applied to an object/shared/executable file. LLVM as well as
modern versions of GNU tools read and write the only type of the options -
ODK_REGINFO. It is exact copy of .reginfo section used by O32 ABI.

llvm-svn: 268485
2016-05-04 10:07:38 +00:00
Rafael Espindola
1dd2b3d1d0 Produce cpio files for --reproduce.
We want --reproduce to

* not rewrite scripts and thin archives
* work with absolute paths

Given that, it pretty much has to create a full directory tree. On windows that
is problematic because of the very short maximum path limit. On most cases
users can still work around it with "--repro c:\r", but that is annoying and
not viable for automated testing.

We then need to produce some form of archive with the files. The first option
that comes to mind is .a files since we already have code for writing them.
There are a few problems with them

The format has a dedicated string table, so we cannot start writing it until
all members are known.
Regular implementations don't support creating directories. We could make
llvm-ar support that, but that is probably not a good idea.
The next natural option would be tar. The problem is that to support long path
names (which is how this started) it needs a "pax extended header" making this
an annoying format to write.

The next option I looked at seems a natural fit: cpio files.

They are available on pretty much every unix, support directories and long path
names and are really easy to write. The only slightly annoying part is a
terminator, but at least gnu cpio only prints a warning if it is missing, which
is handy for crashes. This patch still makes an effort to always create it.

llvm-svn: 268404
2016-05-03 17:30:44 +00:00
Rafael Espindola
d1cbe4df91 Copy thin archive members with --reproduce.
llvm-svn: 268229
2016-05-02 13:54:10 +00:00
Peter Collingbourne
3db410e865 Should fix all remaining MSVC problems.
llvm-svn: 268187
2016-05-01 06:00:09 +00:00
Peter Collingbourne
4f9527065c ELF: New symbol table design.
This patch implements a new design for the symbol table that stores
SymbolBodies within a memory region of the Symbol object. Symbols are mutated
by constructing SymbolBodies in place over existing SymbolBodies, rather
than by mutating pointers. As mentioned in the initial proposal [1], this
memory layout helps reduce the cache miss rate by improving memory locality.

Performance numbers:

           old(s) new(s)
Without debug info:
chrome      7.178  6.432 (-11.5%)
LLVMgold.so 0.505  0.502 (-0.5%)
clang       0.954  0.827 (-15.4%)
llvm-as     0.052  0.045 (-15.5%)
With debug info:
scylla      5.695  5.613 (-1.5%)
clang      14.396 14.143 (-1.8%)

Performance counter results show that the fewer required indirections is
indeed the cause of the improved performance. For example, when linking
chrome, stalled cycles decreases from 14,556,444,002 to 12,959,238,310, and
instructions per cycle increases from 0.78 to 0.83. We are also executing
many fewer instructions (15,516,401,933 down to 15,002,434,310), probably
because we spend less time allocating SymbolBodies.

The new mechanism by which symbols are added to the symbol table is by calling
add* functions on the SymbolTable.

In this patch, I handle local symbols by storing them inside "unparented"
SymbolBodies. This is suboptimal, but if we do want to try to avoid allocating
these SymbolBodies, we can probably do that separately.

I also removed a few members from the SymbolBody class that were only being
used to pass information from the input file to the symbol table.

This patch implements the new design for the ELF linker only. I intend to
prepare a similar patch for the COFF linker.

[1] http://lists.llvm.org/pipermail/llvm-dev/2016-April/098832.html

Differential Revision: http://reviews.llvm.org/D19752

llvm-svn: 268178
2016-05-01 04:55:03 +00:00
Rafael Espindola
fb4f2fedd1 Be sure to always increment the Versym pointer.
It was getting out of sync if we had undefined symbols at the start of
the symbol table.

llvm-svn: 268077
2016-04-29 17:46:07 +00:00
Rafael Espindola
18da0e589a Fix producing undefined reference to __progname.
We were not producing them if the library had version info.

llvm-svn: 268060
2016-04-29 16:23:31 +00:00
Rui Ueyama
fb6d499ed7 ELF: Add -O0 (produce output as fast as possible) mode.
This patch redefines the default optimization level as 1 and adds
new level 0. In the command line, it is -O0. The flag disables
costly but optional features so that the linker produces semantically
correct but larger output quickly. Currently it only disables
section merging.

This flag is not intended to be used for final production linking.
It is intended to be used in compile-link-test cycle.

Time to link clang with debug info is about 2x faster with the flag.

  Head:
  13.24 seconds
  Output size: 1227189664 bytes

  With this patch:
  7.41 seconds
  Output size: 2490281784 bytes

Differential Revision: http://reviews.llvm.org/D19705

llvm-svn: 268056
2016-04-29 16:12:29 +00:00
Simon Atanasyan
ae77ab71d8 [ELF][MIPS] Accept MIPS 64-bit binaries
LLD accepts MIPS 64-bit binaries, supports corresponding eulation (-m)
arguments and emits 64-bit specific ELF flags.

llvm-svn: 268024
2016-04-29 10:39:17 +00:00
Rafael Espindola
156f4ee1c0 Use a single context for lto.
Using multiple context used to be a really big memory saving because we
could free memory from each file while the linker proceeded with the
symbol resolution. We are getting lazier about reading data from the
bitcode, so I was curious if this was still a good tradeoff.

One thing that is a bit annoying is that we still have to copy the
symbol names. The problem is that the names are stored in the Module and
get freed when we move the module bits during linking.

Long term I think the solution is to add a symbol table to the bitcode.
That way IRObject file will not need to use a Module or a Context and we
can drop it while still keeping a StringRef to the names.

This patch is still be an interesting medium term improvement.

When linking llvm-as without debug info this patch is a small speedup:

master: 29.861877513 seconds
patch: 29.814533787 seconds

With debug info the numbers are

master: 34.765181469 seconds
patch: 34.563351584 seconds

The peak memory usage when linking llvm-as with debug info was

master: 599.10MB
patch: 600.13MB
llvm-svn: 267921
2016-04-28 19:30:41 +00:00