Summary:
I also changed the message to print both the ISA and the the architecture
name for incompatible files. Previously it would be quite hard to find the
actual path of the incompatible object files in projects that have many
object files with the same name in different directories.

Reviewers: atanasyan, ruiu

Reviewed By: atanasyan

Subscribers: emaste, sdardis, llvm-commits

Differential Revision: https://reviews.llvm.org/D40958

llvm-svn: 320056

Both ld.bfd and ld.gold can handle this case.

Differential Revision: https://reviews.llvm.org/D40878

llvm-svn: 320006

Differential Revision: https://reviews.llvm.org/D40928

llvm-svn: 320005

This reduces total allocations when linking clang fsds from 263.21MB
to 174.62MB.

This also has some very nice speed improvements on some
benchmarks. Chromium and clang fsds link 6% faster.

llvm-svn: 319976

This patch is to rename check CHECK and make it a C macro, so that
we can evaluate the second argument lazily.

Differential Revision: https://reviews.llvm.org/D40915

llvm-svn: 319974

This brings memory allocations when linking clang from 270.96MB to
267.80MB.

llvm-svn: 319932

Total memory allocation when linking clang goes from 281.80MB to
270.96MB.

llvm-svn: 319930

Linking clang goes from 292.68MB to 281.80MB allocated.

llvm-svn: 319927

Linking clang goes from 300.82MB to 292.68MB allocated.

llvm-svn: 319926

Reduce total allocation when linking clang from 320.04MB to 300.82MB.

llvm-svn: 319924

This avoids allocating the error message when there is no error that
check requires.

It avoids the code duplication of inlining check.

llvm-svn: 319922

This takes memory allocations when linking clang-fsds from 342.08MB to
320.04MB.

llvm-svn: 319918

According to heaptrack this takes "bytes allocated in total" when
linking clang-fsds from 405.69MB to 342.08MB.

llvm-svn: 319916

As mentioned in PR35471, shared functions for which
.plt entry address is used shows up in bfd's map files. 
Patch teaches LLD to do the same.

Differential revision: https://reviews.llvm.org/D40839

llvm-svn: 319879

This is a constructed testcase I noticed while working on another
patch.

llvm-svn: 319874

We fill executable sections with trap instructions (0xcc or equivalent).
If a .gnu.hash section was put into an executable segment, we created
corrupted .gnu.hash section. This patch fixes the issue.

llvm-svn: 319863

Reviewers: pcc, ruiu

Subscribers: llvm-commits, emaste

Differential Revision: https://reviews.llvm.org/D40868

llvm-svn: 319860

Differential Revision: https://reviews.llvm.org/D40824

llvm-svn: 319787

Forgot these from r319780

llvm-svn: 319781

 
Add a new file AArch64ErrataFix.cpp that implements the logic to scan for
the Cortex-A53 Erratum 843419. This involves finding all the executable
code, disassembling the instructions that might trigger the erratum and
reporting a message if the sequence is detected.

At this stage we do not attempt to fix the erratum, this functionality
will be added in a later patch. See D36749 for proposal.

Differential Revision: https://reviews.llvm.org/D36742

llvm-svn: 319780

With fix:
Specify -soname for input dso to fix up the .dynstr section
size in different environments.

Original commit message:

As mentioned in PR35471, copied symbols did not show
in --Map output. Patch fixes that.

Differential revision: https://reviews.llvm.org/D40785

llvm-svn: 319769

When a linker script is used with a pattern like { *(.bss .bss.*) } the
InX::BssRelRo section will match against .bss.*. By matching on the name
only, in the same way that .data.rel.ro works we prevent this
from happening, but permit scripts that want to explicitly provide
a .bss.rel.ro OutputSection.
    
Differential Revision: https://reviews.llvm.org/D40735

llvm-svn: 319755

It broke bots:
http://lab.llvm.org:8011/builders/lld-x86_64-darwin13/builds/15570/steps/test_lld/logs/stdio
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/10930/steps/check-lld%20asan/logs/stdio
http://lab.llvm.org:8011/builders/lld-x86_64-win7/builds/16336/steps/test%20lld/logs/stdio

According to outputs,
.dynstr section has different sizes for some reason.

llvm-svn: 319749

As mentioned in PR35471, copied symbols did not show
in --Map output. Patch fixes that.

Differential revision: https://reviews.llvm.org/D40785

llvm-svn: 319747

Previously, lld exited with an error status if the only option given to
the command was -v. GNU linkers gracefully exit in that case. This patch
makes lld behave like GNU.

Note that even with this patch, lld's -v and --version options behave
slightly differently than GNU linkers' counterparts. For example,
if you run `ld.bfd -v -v`, the version string is printed out twice.
But that is an edge case that I don't think we need to take care of.

Fixes https://bugs.llvm.org/show_bug.cgi?id=31582

Differential Revision: https://reviews.llvm.org/D40810

llvm-svn: 319717

This change actually makes the linker slightly faster. My observation
is that, with this patch, link time of clang without debug is about 1%
faster.

Differential Revision: https://reviews.llvm.org/D40697

llvm-svn: 319600

PR35478 https://bugs.llvm.org/show_bug.cgi?id=35478 points out a flaw
in the implementation of r318924 from D40364. The implementation
depends on the Size field being set or the SyntheticSection::empty()
being accurate. These functions are not reliable as some linker script
commands that have yet to be processed may affect the results, causing
some non-zero size sections to be reported as zero size.

I think the first step is to revert r318924 and come up with a better
solution for the underlying problem rather than trying to layer more
heuristics onto the zero sized output section.

Chances are I'll be out of office by the time anyone sees this so feel
free to commit the revert if you agree with me.

Fixes PR35478

Current thoughts on the underlying problem:

Revisiting the motivation for adding the zero size check in the first
place; it was to prevent 0 sized SyntheticSections that a user does
not have full control over from needlessly breaking the PT_GNU_RELRO,
rather than trying to accommodate arbitrarily complex linker
scripts. Looking at the code, it looks like
removeUnusedSyntheticSections() should remove zero sized synthetic
sections. It does, but it doesn't set the Parent to nullptr, this has
the side effect that Sec == InX::BssRelRo->getParent() will make the
parent OutputSection of InX::BssRelRo RelRo even if there is no
InX::BssRelRo.

I tried a quick experiment with setting the Parent to nullptr and this
flushed out a few interesting test failures, it feels like playing
Jenga with every change:

    In the isRelroSection() we have to consider the case where there
    is no .plt and .plt.got but there is a ifunc plt with accompanying
    (ifunc .got or .plt.got)

    The PPC64 has PltHeaderSize == 0. Unfortunately HeaderSize == 0 is
    used to choose between the ifunc plt or normal plt. We seem to get
    away with this at the moment, but tests start to fail when Parent
    is set to nullptr for the .got.plt.

    The InX::BssRelRo and InX::Bss never get their sizes set and they
    are always removed by removeUnusedSyntheticSections(), their
    purpose seems to be as some kind of proxy for add .bss or
    .bss.relro InputSections into their parent OutputSections, they
    therefore don't behave like other SyntheticSections anyway.

My thinking is that some work is needed to make sure that the Sec ==
SyntheticSection->getParent() does a bit more checking before
returning true, particularly for InX::BssRelRo as that has special
behaviour. I'll hope to post something for review as soon as possible.

Patch by Peter Smith!

llvm-svn: 319563

It is a follow up for 
https://reviews.llvm.org/D40652 requested during review.

llvm-svn: 319527

[ELF] - Produce relocation section name consistent with output section name when --emit-reloc used with linker script.

This is for "Bug 35474 - --emit-relocs produces wrongly-named reloc sections".

LLD currently for scripts like:

.text.boot : { *(.text.boot) }
emits relocation section with name .rela.text because does not take
redefined name of output section into account and builds section name
using rules for non-scripted case. Patch fixes this oddness.

Differential revision: https://reviews.llvm.org/D40652

llvm-svn: 319526

Our on-disk hash table was unnecessarily large. The cost of collision is
not high in the .gnu.hash table because each symbol in the .gnu.hash
table has a hash value with it. So, for each collided symbol, the
dynamic linker just compares an integer, which is pretty cheap.

This patch increases the load factor by about 8. Here's a comparison.

  $ readelf --histogram libclangSema.so.6.0.0svn-new-lld
  Histogram for `.gnu.hash' bucket list length (total of 582 buckets):
   Length  Number     % of total  Coverage
        0  11         (  1.9%)
        1  35         (  6.0%)      1.5%
        2  93         ( 16.0%)      9.5%
        3  108        ( 18.6%)     23.4%
        4  121        ( 20.8%)     44.1%
        5  86         ( 14.8%)     62.6%
        6  63         ( 10.8%)     78.8%
        7  38         (  6.5%)     90.2%
        8  18         (  3.1%)     96.4%
        9  6          (  1.0%)     98.7%
       10  3          (  0.5%)    100.0%

  $ readelf --histogram libclangSema.so.6.0.0svn-old-lld
  Histogram for `.gnu.hash' bucket list length (total of 4093 buckets):
   Length  Number     % of total  Coverage
        0  1498       ( 36.6%)
        1  1545       ( 37.7%)     37.7%
        2  712        ( 17.4%)     72.5%
        3  251        (  6.1%)     90.9%
        4  66         (  1.6%)     97.3%
        5  16         (  0.4%)     99.3%
        6  5          (  0.1%)    100.0%

  $ readelf --histogram libclangSema.so.6.0.0svn-bfd
  Histogram for `.gnu.hash' bucket list length (total of 1004 buckets):
   Length  Number     % of total  Coverage
      0  92         (  9.2%)
        1  227        ( 22.6%)      9.8%
        2  266        ( 26.5%)     32.6%
        3  222        ( 22.1%)     61.2%
        4  115        ( 11.5%)     81.0%
        5  55         (  5.5%)     92.8%
        6  21         (  2.1%)     98.2%
        7  6          (  0.6%)    100.0%

  $ readelf --histogram libclangSema.so.6.0.0svn-gold
  Histogram for `.gnu.hash' bucket list length (total of 2053 buckets):
   Length  Number     % of total  Coverage
        0  671        ( 32.7%)
        1  709        ( 34.5%)     30.4%
        2  470        ( 22.9%)     70.7%
        3  141        (  6.9%)     88.9%
        4  54         (  2.6%)     98.2%
        5  5          (  0.2%)     99.2%
        6  3          (  0.1%)    100.0%

Differential Revision: https://reviews.llvm.org/D40683

llvm-svn: 319503

The ELF spec says

Symbols with section index SHN_COMMON may appear only in relocatable
objects.

Currently lld can produce file that break that requirement.

llvm-svn: 319473

This particular reportDuplicate is only used with Defined.

llvm-svn: 319451

When a linker script has "foo = bar" and bar is the result of a copy
relocation foo should point to the same location in .bss.

This is part of a growing evidence that copy relocations should be
implemented by using replaceSymbol to replace the SharedSymbol with a
Defined.

llvm-svn: 319449

Since MarkLive.cpp is the place where we set Live flags for
other sections, it looks correct to do that there.
Benefit is that we stop spreading GC logic outsize of MarkLive.cpp.

Differential revision: https://reviews.llvm.org/D40454

llvm-svn: 319435

llvm-svn: 319404

llvm-svn: 319403

Thanks to Davide for noticing.

llvm-svn: 319401

Looks like all tests pass without this `isLocal()`.

Differential Revision: https://reviews.llvm.org/D39780

llvm-svn: 319395

llvm-svn: 319394

We are already paying the cost of storing a InputFile in every
Symbol, so use it uniformly.

llvm-svn: 319378