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

Summary:
This adds support for reporting multiple errors in a single invocation of lld-link. The limit defaults to 20 and can be changed with the /ERRORLIMIT command line parameter, or set to unlimited by passing a value of 0.

This is a new attempt after r295507, which was reverted because opening files raced with exiting early, causing the test to be flaky. This version avoids the race by exiting before calling enqueuePath.

Reviewers: pcc, ruiu

Reviewed By: ruiu

Subscribers: llvm-commits, dblaikie

Differential Revision: https://reviews.llvm.org/D31688

llvm-svn: 299496

llvm-svn: 299495

llvm-svn: 299494

llvm-svn: 299493

llvm-svn: 299492

See matching MC change in https://reviews.llvm.org/D31554.

llvm-svn: 299480

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

Summary:
The TypeTableBuilder provides stable storage for type records. We don't
need to copy all of the bytes into a flat vector before adding it to the
TpiStreamBuilder.

This makes addTypeRecord take an ArrayRef<uint8_t> and a hash code to go
with it, which seems like a simplification.

Reviewers: ruiu, zturner, inglorion

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31634

llvm-svn: 299406

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

Summary: This change adds tests for r299268.

Reviewers: pcc, rnk

Reviewed By: pcc

Subscribers: mehdi_amini, llvm-commits, Prazek

Differential Revision: https://reviews.llvm.org/D31549

llvm-svn: 299272

This is a test change applicable for ARM targets.

Previously LLVM would generate a mapping symbol when code contains only
data. This was changed as part of

https://reviews.llvm.org/D30724

and to be more close to the ARM ELF ABI.

The test case is changed to check for behavior with minimal changes.

Patch by Shankar Easwaran

Differential Revision: https://reviews.llvm.org/D31500

llvm-svn: 299212