GNU linkers define __bss_start symbol.
Patch teaches LLD to do that. This is PR32051.

Below is part of standart ld.bfd script:

.data1          : { *(.data1) }
  _edata = .; PROVIDE (edata = .);
  . = .;
  __bss_start = .;
  .bss            :
  {
Currently LLD can emit up to 3 .bss* sections as one of testcase shows.
Implementation inserts this symbol before first .bss* output section.

Differential revision: https://reviews.llvm.org/D30419

llvm-svn: 299528

It was not NFC unfortunaly,
one of changes decrements begin() iterator and
that is not allowed by MSVS.

llvm-svn: 299525

llvm-svn: 299521

llvm-svn: 299520

Looks like we can use consume() in many more places.

llvm-svn: 299519

llvm-svn: 299518

This class is used only within this file, so it can be file-local.

llvm-svn: 299516

LinkerScript.cpp contains both the linker script processor and the
linker script parser. I put both into a single file, but the file grown
too large, so it's time to put them into two different files.

llvm-svn: 299515

llvm-svn: 299514

ScriptParser is not a ScriptLexer, so this should be a private inheritance.

llvm-svn: 299513

llvm-svn: 299512

A for-loop is more boring than a find_if, but I think this is easier to read.

llvm-svn: 299511

llvm-svn: 299509

llvm-svn: 299508

llvm-svn: 299506

It simplifies variable types.

llvm-svn: 299505

llvm-svn: 299504

llvm-svn: 299503

llvm-svn: 299502

`!V.size()` where V is a vector is equivalent to `V.empty()`.

llvm-svn: 299501

llvm-svn: 299500

llvm-svn: 299499

This should improve readability.

llvm-svn: 299498

llvm-svn: 299495

llvm-svn: 299494

llvm-svn: 299493

llvm-svn: 299492

The ELF spec says:

all of the non-default visibility attributes, when applied to a symbol
reference, imply that a definition to satisfy that reference must be
provided within the current executable or shared object.

But we were trying to resolve those undef references to shared
symbols. That causes odd results like creating a got entry with
a relocation pointing to 0.

llvm-svn: 299464

As with the changes made in r297645, we do not want a potentially long link to
be run, if it will ultimately fail because the map file is not writable. This
change reuses the same functionality as the output file path check. See
https://reviews.llvm.org/D30449 for further justification and explanations.

Reviewers: ruiu

Differential Revision: https://reviews.llvm.org/D31603

llvm-svn: 299420

    
The existing names for the ARM and Thumb Thunks highlight their current
use as interworking Thunks. These Thunks can also be used for range
extension Thunks where there is no state change. This change makes the name
more generic so it is suitable for range extension.

Differential Revision: https://reviews.llvm.org/D31605

llvm-svn: 299418

Previous error message style:

  error: /home/alice/src/bar.c:12: relocation R_X86_64_PLT32 cannot refer to absolute symbol 'answer' defined in /home/alice/src/foo.o

New error message style:

  error: relocation R_X86_64_PLT32 cannot refer to absolute symbol: foo
  >>> defined in /home/alice/src/foo.o
  >>> referenced by bar.c:12 (/home/alice/src/bar.c:12)
  >>>               /home/alice/src/bar.o:(.text+0x1)

llvm-svn: 299390

llvm-svn: 299377

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

llvm-svn: 299289

This patch is intended to improve readability of "duplicate symbol"
error messages.

Without this patch:

  /ssd/clang/bin/ld.lld: error: /ssd/llvm-project/lld/ELF/Relocations.cpp:1054: duplicate symbol 'lld::elf::demangle(llvm::StringRef)'
  /ssd/clang/bin/ld.lld: error: /ssd/llvm-project/lld/ELF/Strings.cpp:93: previous definition was here

With this patch:

  /ssd/clang/bin/ld.lld: error: duplicate symbol: lld::elf::demangle(llvm::StringRef)
  >>> defined at Strings.cpp:93 (/ssd/llvm-project/lld/ELF/Strings.cpp:93)
  >>>            Strings.cpp.o:(lld::elf::demangle(llvm::StringRef)) in archive lib/liblldELF.a
  >>> defined at Relocations.cpp:1054 (/ssd/llvm-project/lld/ELF/Relocations.cpp:1054)
  >>>            Relocations.cpp.o:(.text+0x4C30) in archive lib/liblldELF.a

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

Differential Revision: https://reviews.llvm.org/D31507

llvm-svn: 299280

llvm-svn: 299208

llvm-svn: 299184

http://bb.pgr.jp/builders/i686-mingw32-RA-on-linux/builds/25073/steps/build_llvmclang/logs/stdio

llvm-svn: 299171

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

llvm-svn: 299128