Commit Graph

4548 Commits

Author SHA1 Message Date
Rafael Espindola 5af073e3bf Make createSyntheticSections a static helper. NFC.
llvm-svn: 320200
2017-12-08 21:50:29 +00:00
Rafael Espindola 471001a7b4 Make findSection a static function. NFC.
llvm-svn: 320198
2017-12-08 21:44:11 +00:00
Peter Collingbourne d1eefa993b ELF: Ignore --long-plt flag.
This flag can be ignored because we always emit long PLTs.

Differential Revision: https://reviews.llvm.org/D41025

llvm-svn: 320178
2017-12-08 19:36:19 +00:00
Rafael Espindola 1dd30ddd45 Make addReservedSymbols a static helper. NFC.
llvm-svn: 320175
2017-12-08 19:13:27 +00:00
Alexander Richardson f5ef4e5616 Print the bad value and required alignment for unaligned relocations
Reviewers: ruiu, grimar

Reviewed By: ruiu

Subscribers: emaste, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D40963

llvm-svn: 320147
2017-12-08 14:53:14 +00:00
Rui Ueyama 04c821c7e3 Use lambda to simplify code.
Differential Revision: https://reviews.llvm.org/D40994

llvm-svn: 320130
2017-12-08 02:20:50 +00:00
Rafael Espindola d182aaa69d Further simplify .gnu.hash writing. NFC.
llvm-svn: 320072
2017-12-07 18:59:29 +00:00
Rafael Espindola f9f2abe7bd Simplify .gnu.hash writing. NFC.
llvm-svn: 320070
2017-12-07 18:51:19 +00:00
Rafael Espindola 50ca10bb58 Avoid using a temporary std::vector.
With this memory usage when linking clang goes from 174.62MB to
172.77MB.

llvm-svn: 320069
2017-12-07 18:46:03 +00:00
Alexander Richardson 280252c6d1 [ELF][mips] Print the full file path for files with incompatible ISA
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
2017-12-07 16:08:59 +00:00
Igor Kudrin 892b14658e [ELF] Handle multiple "--version-script" options.
Both ld.bfd and ld.gold can handle this case.

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

llvm-svn: 320006
2017-12-07 03:25:39 +00:00
Rui Ueyama c0081639cc Remove checkToString functions and use toString instead.
Differential Revision: https://reviews.llvm.org/D40928

llvm-svn: 320005
2017-12-07 03:24:57 +00:00
Rafael Espindola 91fac59a81 Add a call to std::vector::reserve.
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
2017-12-06 22:32:19 +00:00
Rui Ueyama bdc5150984 Always evaluate the second argument for CHECK() lazily.
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
2017-12-06 22:08:17 +00:00
Rafael Espindola b6e2ca4597 Convert a check to checkLazy.
This brings memory allocations when linking clang from 270.96MB to
267.80MB.

llvm-svn: 319932
2017-12-06 19:17:20 +00:00
Rafael Espindola 0ab9d8b6ed Add an early return.
Total memory allocation when linking clang goes from 281.80MB to
270.96MB.

llvm-svn: 319930
2017-12-06 19:13:23 +00:00
Rafael Espindola aca3df5479 Convert a few uses of check to checkLazy.
Linking clang goes from 292.68MB to 281.80MB allocated.

llvm-svn: 319927
2017-12-06 19:08:10 +00:00
Rafael Espindola 5b491a29fb Convert a call to check to checkLazy.
Linking clang goes from 300.82MB to 292.68MB allocated.

llvm-svn: 319926
2017-12-06 19:02:12 +00:00
Rafael Espindola c8dfde2051 Replace one use of check with checkLazy.
Reduce total allocation when linking clang from 320.04MB to 300.82MB.

llvm-svn: 319924
2017-12-06 18:56:22 +00:00
Rafael Espindola 9ffa988b5d Add a checkLazy error checking variant.
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
2017-12-06 18:52:13 +00:00
Rafael Espindola 8b97611190 Don't allocate memory for an error message on success.
This takes memory allocations when linking clang-fsds from 342.08MB to
320.04MB.

llvm-svn: 319918
2017-12-06 18:39:22 +00:00
Rafael Espindola f4c3239824 Don't allocate an error message when there is no error.
According to heaptrack this takes "bytes allocated in total" when
linking clang-fsds from 405.69MB to 342.08MB.

llvm-svn: 319916
2017-12-06 18:31:11 +00:00
George Rimar ba7afd7043 [ELF] - Show .plt symbols in -Map output.
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
2017-12-06 08:36:21 +00:00
Rafael Espindola a834b529c3 Fix a crash.
This is a constructed testcase I noticed while working on another
patch.

llvm-svn: 319874
2017-12-06 02:53:43 +00:00
Rui Ueyama c4e50bfc55 Fix broken .gnu.hash section if -no-rosegment is given.
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
2017-12-06 00:49:48 +00:00
Evgeniy Stepanov 9ac3154d10 [lld] Fix handling of wildcards in dynamic lists.
Reviewers: pcc, ruiu

Subscribers: llvm-commits, emaste

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

llvm-svn: 319860
2017-12-06 00:14:04 +00:00
Sam Clegg 7e7566323d toString function take a const refs where possible
Differential Revision: https://reviews.llvm.org/D40824

llvm-svn: 319787
2017-12-05 16:50:46 +00:00
Peter Smith 6a954157dd [ELF] AArch64 Errata fix, add missing files.
Forgot these from r319780

llvm-svn: 319781
2017-12-05 16:04:45 +00:00
Peter Smith 732cd8cbef [ELF] Implement scanner for Cortex-A53 Erratum 843419
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
2017-12-05 15:59:05 +00:00
George Rimar 31cd5da582 Recommit r319747 "[ELF] - Show copy relocated symbols in a --Map file output."
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
2017-12-05 14:23:18 +00:00
Peter Smith 7c40f93f38 [ELF] InX::BssRelRo should check section contents before marking relro
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
2017-12-05 11:15:58 +00:00
George Rimar fe52e0064b [ELF] - Revert r319747 "[ELF] - Show copy relocated symbols in a --Map file output.".
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
2017-12-05 09:38:05 +00:00
George Rimar d9ae97cdb6 [ELF] - Show copy relocated symbols in a --Map file output.
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
2017-12-05 09:13:45 +00:00
Rui Ueyama be61cc90c4 Make the behavior of the -v option more closer to GNU linkers.
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
2017-12-05 00:03:41 +00:00
Rui Ueyama 2278826c60 Cache modulo values for the .gnu.hash section.
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
2017-12-02 00:37:13 +00:00
Rafael Espindola b70824c1b8 Revert r318924 Skip over empty sections when checking for contiguous relro
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
2017-12-01 18:14:14 +00:00
George Rimar 196be4a18e [ELF] - Rename excessive variable. NFC.
It is a follow up for 
https://reviews.llvm.org/D40652 requested during review.

llvm-svn: 319527
2017-12-01 09:14:56 +00:00
George Rimar 78e27e830d [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
2017-12-01 09:04:52 +00:00
Rui Ueyama 1cf7f9cc80 Make .gnu.hash section smaller.
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
2017-11-30 23:59:40 +00:00
Rafael Espindola 477ff12411 Error on -no-define-common if the output is not relocatable.
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
2017-11-30 20:46:33 +00:00
Rafael Espindola b2ee25ac8a Simplify. NFC.
This particular reportDuplicate is only used with Defined.

llvm-svn: 319451
2017-11-30 18:02:04 +00:00
Rafael Espindola de38b3d22f Handle copy relocations in symbol assignments.
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
2017-11-30 17:51:10 +00:00
George Rimar 2e610cd470 [ELF] - Handle EhInputSection Live bit in MarkLive.cpp
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
2017-11-30 14:01:06 +00:00
Rafael Espindola 568ee2c089 Don't crash on invalid.
llvm-svn: 319404
2017-11-30 06:18:31 +00:00
Rafael Espindola bdcfb178b5 Delete dead code.
llvm-svn: 319403
2017-11-30 05:52:42 +00:00
Rafael Espindola 8ce6db0c4b Error instead of ignoring broken debug info.
Thanks to Davide for noticing.

llvm-svn: 319401
2017-11-30 05:37:35 +00:00
Rui Ueyama 1bf618a9da Remove unused condition.
Looks like all tests pass without this `isLocal()`.

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

llvm-svn: 319395
2017-11-30 01:08:09 +00:00
Rui Ueyama 8ed548a481 Fix typo.
llvm-svn: 319394
2017-11-30 01:04:26 +00:00
Rafael Espindola dfebd3601d Use Symbol::File directly.
We are already paying the cost of storing a InputFile in every
Symbol, so use it uniformly.

llvm-svn: 319378
2017-11-29 22:47:35 +00:00
Rafael Espindola 07b7ee4394 Simplify. NFC.
llvm-svn: 319370
2017-11-29 22:20:03 +00:00