Commit Graph

199 Commits

Author SHA1 Message Date
Konstantin Zhuravlyov 82a6199140 AMDGPU/LLD: Remove the use of binary file from one of the AMDGPU tests
Differential Revision: https://reviews.llvm.org/D43413

llvm-svn: 325404
2018-02-16 22:55:36 +00:00
Peter Collingbourne 09e04af42f ELF: Stop collecting a list of symbols in ArchiveFile.
There seems to be no reason to collect this list of symbols.

Also fix a bug where --exclude-libs would apply to all symbols that
appear in an archive's symbol table, even if the relevant archive
member was not added to the link.

Differential Revision: https://reviews.llvm.org/D43369

llvm-svn: 325380
2018-02-16 20:23:54 +00:00
James Henderson de300e66bb [ELF] Add warnings for various symbols that cannot be ordered
There are a number of different situations when symbols are requested
to be ordered in the --symbol-ordering-file that cannot be ordered for
some reason. To assist with identifying these symbols, and either
tidying up the order file, or the inputs, a number of warnings have
been added. As some users may find these warnings unhelpful, due to how
they use the symbol ordering file, a switch has also been added to
disable these warnings.

The cases where we now warn are:

 * Entries in the order file that don't correspond to any symbol in the input
 * Undefined symbols
 * Absolute symbols
 * Symbols imported from shared objects
 * Symbols that are discarded, due to e.g. --gc-sections or /DISCARD/ linker script sections
 * Multiple of the same entry in the order file

Reviewed by: rafael, ruiu

Differential Revision: https://reviews.llvm.org/D42475

llvm-svn: 325125
2018-02-14 13:36:22 +00:00
Rui Ueyama 3cd48fb124 Remove 'z' in .zdebug when decompressing a section.
When decompressing a compressed debug section, we drop SHF_COMPRESSED
flag but we didn't drop "z" in ".zdebug" section name. This patch does
that for consistency.

This change also fixes the issue that .zdebug_gnu_pubnames are not
dropped when we are creating a .gdb_index section.

llvm-svn: 324949
2018-02-12 22:25:45 +00:00
Simon Atanasyan 85815a3149 [ELF][MIPS] Ignore incorrect version definition index for _gp_disp symbol
MIPS BFD linker puts _gp_disp symbol into DSO files and assigns zero
version definition index to it. This value means 'unversioned local
symbol' while _gp_disp is a section global symbol. We have to handle
this bug in the LLD because BFD linker is used for building MIPS
toolchain libraries.

Differential revision: https://reviews.llvm.org/D42486

llvm-svn: 324467
2018-02-07 10:02:49 +00:00
James Henderson 9c6e2fd5a4 [ELF] Add --print-icf-sections flag
Currently ICF information is output through stderr if the "--verbose"
flag is used. This differs to Gold for example, which uses an explicit
flag to output this to stdout. This commit adds the
"--print-icf-sections" and "--no-print-icf-sections" flags and changes
the output message format for clarity and consistency with
"--print-gc-sections". These messages are still output to stderr if
using the verbose flag. However to avoid intermingled message output to
console, this will not occur when the "--print-icf-sections" flag is
used.

Existing tests have been modified to expect the new message format from
stderr.

Patch by Owen Reynolds.

Differential Revision: https://reviews.llvm.org/D42375

Reviewers: ruiu, rafael

Reviewed by: 

llvm-svn: 323976
2018-02-01 16:00:46 +00:00
Rafael Espindola 8e2fc4f3f8 Don't mark a shared library as needed because of a lazy symbol.
Fixes PR36029.

llvm-svn: 323221
2018-01-23 16:59:20 +00:00
Rafael Espindola 7e6aeb614c Fix another case we used the wrong visibility.
In here too we want the computed output visibility.

llvm-svn: 322586
2018-01-16 19:02:46 +00:00
Rafael Espindola d3ec3e5684 Add an extra test. NFC.
Without this all test would pass if the visibility checks were removed
from SymbolTable::addShared and SymbolTable::addUndefined.

llvm-svn: 322583
2018-01-16 18:53:09 +00:00
Rafael Espindola 3c3544652b Fix another case we were using the wrong visibility.
llvm-svn: 322580
2018-01-16 18:21:23 +00:00
Rafael Espindola b5506e6baf Rename --icf-data and add a corresponding flag for functions.
When we have --icf=safe we should be able to define --icf=all as a
shorthand for --icf=safe --ignore-function-address-equality.

For now --ignore-function-address-equality is used only to control
access to non preemptable symbols in shared libraries.

llvm-svn: 322152
2018-01-10 01:37:36 +00:00
James Henderson e1689689d8 [ELF] Compress debug sections after assignAddresses and support custom layout
Previously, in r320472, I moved the calculation of section offsets and sizes
for compressed debug sections into maybeCompress, which happens before
assignAddresses, so that the compression had the required information. However,
I failed to take account of relocations that patch such sections. This had two
effects:

1. A race condition existed when a debug section referred to a different debug
section (see PR35788).
2. References to symbols in non-debug sections would be patched incorrectly.
This is because the addresses of such symbols are not calculated until after
assignAddresses (this was a partial regression caused by r320472, but they
could still have been broken before, in the event that a custom layout was used
in a linker script).

assignAddresses does not need to know about the output section size of
non-allocatable sections, because they do not affect the value of Dot. This
means that there is no longer a reason not to support custom layout of
compressed debug sections, as far as I'm aware. These two points allow for
delaying when maybeCompress can be called, removing the need for the loop I
previously added to calculate the section size, and therefore the race
condition. Furthermore, by delaying, we fix the issues of relocations getting
incorrect symbol values, because they have now all been finalized.

llvm-svn: 321986
2018-01-08 10:17:03 +00:00
Shoaib Meenai 0c958fba14 [ELF] Only scan executables for shlib undefined symbols
If using a version script with a `local: *` in it, symbols in shared
libraries will still get default visibility if another shared library on
the link line has an undefined reference to the symbol. This is quite
surprising. Neither bfd nor gold have this behavior when linking a
shared library, and none of LLD's tests fail without this behavior, so
it seems safe to limit scanShlibUndefined to executables.

As far as executables are concerned, gold doesn't do any automatic
default visibility marking, and bfd issues a link error about a shared
library having a reference to a hidden symbol rather than silently
giving that symbol default visibility. I think bfd's behavior here is
preferable to LLD's, but that's something to be considered in a
follow-up.

Differential Revision: https://reviews.llvm.org/D41524

llvm-svn: 321578
2017-12-30 08:00:44 +00:00
Rafael Espindola 465e7c94ed Allow copy relocation with -z notext.
This makes adjustExpr a bit simpler too IMHO.

It seems that some of the complication around relocation processing
is that we are trying to create copy relocations too early. It seems
we could handle a few simple cases first and continue.

llvm-svn: 321507
2017-12-28 00:23:49 +00:00
Rafael Espindola e2e070c6c4 Don't try to preempt protected symbols with -z notext.
I will send a followup patch removing the FIXME this patch adds.

llvm-svn: 321499
2017-12-27 20:53:13 +00:00
Rafael Espindola a9c490b71d Allow relocations in rw sections to create plt entries.
If a relocation cannot be implemented by the dynamic linker and the
section is rw, allow creating a plt entry to use as the function
address as if the section was ro.

This matches bfd and gold. It also matches our behavior with -z
notext.

llvm-svn: 321430
2017-12-24 19:02:10 +00:00
George Rimar 3bdf6baa25 [ELF] - Allow using PLT relocations when "-z notext" is given.
This is part of PR35720.

Currently LLD allows dynamic relocations against text when -z notext is given.
Though for non-PIC relocations like R_X86_64_PC32 that does not work,
we produce "relocation R_X86_64_PC32 cannot be used against shared object;"
error because they may overflow in runtime.

Solution implemented is to use PLT for them.

Differential revision: https://reviews.llvm.org/D41541

llvm-svn: 321400
2017-12-23 09:00:37 +00:00
Rafael Espindola b308cace84 Fix crash on invalid.
We would fail an assert if a shared library had a local symbol after
sh_info.

llvm-svn: 320667
2017-12-14 05:01:49 +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 3a02234e0d Make this test a bit less confusing.
Before this patch foo and bar have the same address as .text is empty.

llvm-svn: 319877
2017-12-06 03:35:40 +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
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
Rafael Espindola 97d05f95b9 Copy the visibility in copyFrom.
This is simpler and matches bfd's behavior on the changed test.

llvm-svn: 319248
2017-11-28 23:06:09 +00:00
Rafael Espindola 1d4b3023dc Bring back r319008.
This includes a fix to mark copy reloc aliases as used.

Original message:

[ELF] Do not keep symbols if they referenced only from discarded sections.

This patch also ensures that in case of "--as-needed" is used,
DT_NEEDED entries are not created if they are required only by
these eliminated symbols.

llvm-svn: 319215
2017-11-28 20:17:58 +00:00
Rafael Espindola b45c164fc2 Handle binding in --wrap.
Copying the binding seems reasonable and matches the bfd behavior.

llvm-svn: 319196
2017-11-28 18:02:22 +00:00
Igor Kudrin a46522f369 Revert r319008, "[ELF] Do not keep symbols if they referenced only from discarded sections."
and r319051, "Add a missing test."

r319008 broke the LTO bots;
r319051 depends on changes in r319008.

llvm-svn: 319154
2017-11-28 08:39:40 +00:00
Igor Kudrin 40007586fc [ELF] Do not keep symbols if they referenced only from discarded sections.
This patch also ensures that in case of "--as-needed" is used,
DT_NEEDED entries are not created if they are required only by
these eliminated symbols.

Differential Revision: https://reviews.llvm.org/D38790

llvm-svn: 319008
2017-11-27 05:51:10 +00:00
Igor Kudrin d95c74ec81 [ELF] Make tests with undefined symbols more explicit.
Differential Revision: https://reviews.llvm.org/D40253

llvm-svn: 318939
2017-11-24 06:42:32 +00:00
Rafael Espindola 83f73f7908 Make a test stricter.
It now has a DT_NEEDED that could be removed by --gc-sections and one
that cannot. Without this all tests would pass if --gc-sections just
removed all DT_NEEDED.

llvm-svn: 318937
2017-11-23 23:40:33 +00:00
Rafael Espindola 458173e802 Use 64 bits for the shared symbol size again.
We might want to drop support for such large symbols, but that should
be an explicit decision with a testcase.

llvm-svn: 316931
2017-10-30 17:43:16 +00:00
Rafael Espindola 566dbdc2fd Skip abs symbols when handling copy reloc aliases.
Since we now only check st_value, we have to consider the case where
the section index is special.

llvm-svn: 316928
2017-10-30 17:26:12 +00:00
Konstantin Zhuravlyov b71d1b8a54 LLD/ELF/AMDGPU: Process AMDGPU-specific e_flags
Differential Revision: https://reviews.llvm.org/D39140

llvm-svn: 316483
2017-10-24 19:05:32 +00:00
Rafael Espindola af6c9edc4b Correctly handle shared and lazy symbols.
I will try to make this API a bit less error prone, but for now just
get another test passing.

llvm-svn: 315645
2017-10-13 00:06:38 +00:00
Davide Italiano db710f28e6 [ELF] Try to not emit weird diagnostics on undefined symbols.
Fixes PR34872.

Differential Revision:  https://reviews.llvm.org/D38712

llvm-svn: 315487
2017-10-11 18:37:24 +00:00
Rafael Espindola 469350810a Refine our --wrap implementation.
Before this patch we would copy foo into real_foo and wrap_foo into
foo. The net result is that __wrap_foo shows up twice in the symbol
table.

With this patch we:

* save a copy of __real_foo before copying foo.
* drop one of the __wrap_foo from the symbol table.
* if __real_foo was not undefined, add a *new* symbol with that content to
  the symbol table.

The net result is that

Anything using foo now uses __wrap_foo
Anything using __real_foo now uses foo.
Anything using __wrap_foo still does.

And the symbol table has foo, __wrap_foo and __real_foo (if defined).

Which I think is the desired behavior.

llvm-svn: 315097
2017-10-06 20:09:34 +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 11632a9cfb [ELF] - Get rid of precompiled input objects from testcases.
We have verneed1.so, verneed2.so files and verneed.so.sh script
to produce them. They were committed long time ago when LLD
was not yet able to produce some sections for versioning
(".gnu.version_r" I think).

There is no point to have them as binaries anymore. Patch
creates asm inputs instead based on verneed.so.sh content.

Differential revision: https://reviews.llvm.org/D38505

llvm-svn: 314889
2017-10-04 09:46:53 +00:00
Rafael Espindola 100247fde4 Add a test.
This would have found the issues with r313697.

The problem was that that commit mixed the content of different
.eh_frame sections. Unfortunately we had no tests looking inside the
fdes.

llvm-svn: 314433
2017-09-28 17:15:02 +00:00
Rafael Espindola 7415819186 Handle lazy symbols is Symbol::includeInDynsym.
This should fix the lto bootstrap.

It is somewhat hard to remember about lazy symbols deep down in the
link. It might be worth it replacing them with undefined symbols once
we are done adding files.

llvm-svn: 313103
2017-09-13 00:47:06 +00:00
Simon Atanasyan 4f70b30d6f [MIPS] Initial support of microMIPS code linking
The patch implements initial support of microMIPS code linking:
  - Handle microMIPS specific relocations.
  - Emit both R1-R5 and R6 microMIPS PLT records.

For now linking mixed set of regular and microMIPS object files is not
supported. Also the patch does not handle (setup and clear) the
least-significant bit of an address which is utilized as the ISA mode
bit and allows to make jump between regular and microMIPS code without
any thunks.

Differential revision: https://reviews.llvm.org/D37335

llvm-svn: 313028
2017-09-12 13:08:24 +00:00
Rafael Espindola ee6a352a8d Handle lazy symbols is computeIsPreemptible.
llvm-svn: 312812
2017-09-08 18:41:49 +00:00
Rafael Espindola aca2afcc55 Don't depend on these symbols being implicitly global.
This might change in llvm-mc and it is nice to be explicit in a test.

llvm-svn: 308506
2017-07-19 18:24:38 +00:00
Rafael Espindola 3ddf2110d5 Bring back r307364.
In addition this includes a change to prefer symbols with a default
version @@ over unversioned symbols.

Original commit message:

[ELF] - Handle symbols with default version early.

This fixes last testcase provided in PR28414.
In short issue is next: when we had X@@Version symbol in object A,
we did not resolve it to X early. Then when in another object B
we had reference to undefined X, symbol X from archive was fetched.
Since both archive and object A contains another symbol Z, duplicate
symbol definition was triggered as a result.

Correct behavior is to use X@@Version from object A instead and do not fetch
any symbols from archive.

Differential revision: https://reviews.llvm.org/D35059

llvm-svn: 308492
2017-07-19 16:45:05 +00:00
Rui Ueyama 0e0369e535 Revert r307364: [ELF] - Handle symbols with default version early.
This reverts commit r307364 because that change is likely to have
caused https://bugs.llvm.org/show_bug.cgi?id=33820.

llvm-svn: 308239
2017-07-18 00:33:14 +00:00
Rui Ueyama 8d8916d1dd Fix tests for .ctors/.dtors.
They are supposed to contain pointers, so .byte wasn't quite right.

llvm-svn: 308214
2017-07-17 20:42:52 +00:00
George Rimar 638e8a405d [ELF] - Remove dependency on precompiled inputs from -gdb-index testcases.
Previously we used precompiled objects in gdb-index.s and
debug-gnu-pubnames.s testcases. We can avoid that.

Differential revision: https://reviews.llvm.org/D35360

llvm-svn: 308005
2017-07-14 08:26:44 +00:00
Rafael Espindola d3fc0c91e3 Bring back InVersionScript.
We were producing bogus warnings without it.

llvm-svn: 307820
2017-07-12 17:49:17 +00:00
George Rimar d92e1286ed [ELF] - Fix handling of weak symbols from static library when using version script.
When version script was used, binding opf undefined weak symbols sometimes
was calculated as STB_LOCAL, making them non-preemtible what
broke correct relocations handling logic for them.

Fixes PR33738.

Differential revision: https://reviews.llvm.org/D35263

llvm-svn: 307767
2017-07-12 11:09:46 +00:00
George Rimar 4a9cfc8267 [ELF] - Fix functionality treating IFunc definitions in DSOs as functions.
It was intially implemented in D19517 but then broken.
Patch fixes PR33707, testcase is based on PR's case.

Differential revision: https://reviews.llvm.org/D35119

llvm-svn: 307652
2017-07-11 11:40:59 +00:00