Commit Graph

9255 Commits

Author SHA1 Message Date
Rui Ueyama 9b18f50f79 Remove a trivial function.
llvm-svn: 315164
2017-10-08 02:06:03 +00:00
Rui Ueyama e8936bca72 Add comment.
llvm-svn: 315163
2017-10-08 01:55:29 +00:00
Rui Ueyama 10f5867135 Remove redundant initialization code.
llvm-svn: 315158
2017-10-08 00:45:34 +00:00
Rafael Espindola 8bd0c45c7a Inline small function. NFC.
llvm-svn: 315141
2017-10-07 01:08:28 +00:00
Rui Ueyama 8befefb2ea Remove OutputSection::updateAlignment.
I feel it is easier to understand without this function.

llvm-svn: 315140
2017-10-07 00:58:34 +00:00
Rui Ueyama c8e0f79b90 Clarify code by adding a comment.
llvm-svn: 315139
2017-10-07 00:58:19 +00:00
Rui Ueyama 0e2bfb1e3b Merge addInputSec with OutputSection::addSection.
Previously, when we added an input section to an output section, we
called `OutputSectionFactory::addInputSec`. This isn't a good design
because, a factory class is intended to create a new object and
return it, but in this use case, it will never create a new object.
This patch fixes the design flaw.

llvm-svn: 315138
2017-10-07 00:43:31 +00:00
Rui Ueyama 850b554399 Return early. NFC.
llvm-svn: 315137
2017-10-07 00:22:59 +00:00
Rui Ueyama b4175edf16 Remove unused parameters.
llvm-svn: 315133
2017-10-07 00:08:30 +00:00
Rui Ueyama cc6738a439 Use error() instead of warn() to report undefined symbols.
I believe the reason why we used warn() instead of error() to report
undefined symbols is because the older implementation of error() exitted
immediately. Here, we want to find as many undefined symbols as we can,
so I chose to use warn() instead of error().

Now error() does not exit immediately, so it doesn't make sense to keep
them as warnings.

Differential Revision: https://reviews.llvm.org/D38652

llvm-svn: 315131
2017-10-06 23:43:54 +00:00
Rui Ueyama c54d5b16d5 Do not mutate Script->Opt.Commands from a leaf helper function.
Factory::addInputSec added an output section to Script->Opt.Commands,
but that is too subtle. This patch makes it explicit so that it is easy
to see when a new element is added to Script->Opt.Commands.

llvm-svn: 315129
2017-10-06 23:34:43 +00:00
Rui Ueyama d2f225fdef Simplify LinkerScript::addOrphanSections. NFCI.
This patch moves a std::find to a new function. It also removes
the following piece of code. I believe it should be fine because all
tests still pass.

  unsigned Index = std::distance(Opt.Commands.begin(), I);
  assert(Sec->SectionIndex == INT_MAX || Sec->SectionIndex == Index);
  Sec->SectionIndex = Index;

llvm-svn: 315125
2017-10-06 23:06:55 +00:00
Rui Ueyama edafba200f Split addSection into two small functions. NFCI.
addSection function was hard to read because it behaves differently
depending on its arguments but what exactly it does is not clear.
Now it should be better. Still, it is not clear (not what but) why
it does what it does, but I'll take a look at it later.

llvm-svn: 315124
2017-10-06 23:06:40 +00:00
Peter Collingbourne d6924d7474 Reland r315114, "ELF: Export preempted symbols even if there is a dynamic list." which was reverted in r315116.
I hadn't synced past the change that changed the default hash style
to --hash-style=both, so my test had the symbols in the wrong order.

llvm-svn: 315119
2017-10-06 22:09:03 +00:00
Peter Collingbourne accab5908d Revert r315114, "ELF: Export preempted symbols even if there is a dynamic list."
For some reason the symbols get emitted in the wrong order on one of the
buildbots: http://bb9.pgr.jp/#builders/15/builds/180

llvm-svn: 315116
2017-10-06 21:48:39 +00:00
Rui Ueyama 40bd97af34 Make a few member varaibles/functions private.
llvm-svn: 315115
2017-10-06 21:42:37 +00:00
Peter Collingbourne 5a8928c605 ELF: Export preempted symbols even if there is a dynamic list.
Dynamic lists in an executable are additive, not restrictive, so we
must continue to export preempted symbols even with a dynamic list.

This fixes sanitizer interception of libc symbols (and should also fix
symbol preemption by users of sanitizers).

Differential Revision: https://reviews.llvm.org/D38647

llvm-svn: 315114
2017-10-06 21:33:59 +00:00
Rui Ueyama 56c5c63e6d Inline a small function.
llvm-svn: 315113
2017-10-06 21:32:23 +00:00
Rui Ueyama 8ad23dcd8b Revert r314616: Run writeTo() concurrently.
This reverts commit r314616 because nested parallel-for loops can hang.
Our ThreadPoolExecutor is not necessarily able to handle nested calls.

llvm-svn: 315098
2017-10-06 20:12:43 +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
Rui Ueyama e41f9e0651 Inline a small function. NFC.
llvm-svn: 315096
2017-10-06 20:08:51 +00:00
Zachary Turner 96b04b68ed [lit] Improve tool substitution in lit.
This addresses two sources of inconsistency in test configuration
files.

1. Substitution boundaries.  Previously you would specify a
   substitution, such as 'lli', and then additionally a set
   of characters that should fail to match before and after
   the tool.  This was used, for example, so that matches that
   are parts of full paths would not be replaced.  But not all
   tools did this, and those that did would often re-invent
   the set of characters themselves, leading to inconsistency.
   Now, every tool substitution defaults to using a sane set
   of reasonable defaults and you have to explicitly opt out
   of it.  This actually fixed a few latent bugs that were
   never being surfaced, but only on accident.

2. There was no standard way for the system to decide how to
   locate a tool.  Sometimes you have an explicit path, sometimes
   we would search for it and build up a path ourselves, and
   sometimes we would build up a full command line.  Furthermore,
   there was no standardized way to handle missing tools.  Do we
   warn, fail, ignore, etc?  All of this is now encapsulated in
   the ToolSubst class.  You either specify an exact command to
   run, or an instance of FindTool('<tool-name>') and everything
   else just works.  Furthermore, you can specify an action to
   take if the tool cannot be resolved.

Differential Revision: https://reviews.llvm.org/D38565

llvm-svn: 315085
2017-10-06 17:54:46 +00:00
Zachary Turner c981448063 Run pyformat on lit code.
llvm-svn: 315084
2017-10-06 17:54:27 +00:00
Alexander Richardson f52a3b94e1 [ELF][MIPS] Check for overflow when writing R_MIPS_CALL16 and R_MIPS_TLS_GOTTPREL
Summary:
These are 16 bit relocations and not part of a HI/LO pair so we need to
check that they don't overflow.

Reviewers: atanasyan

Reviewed By: atanasyan

Subscribers: ruiu, llvm-commits, emaste, sdardis

Tags: #lld

Differential Revision: https://reviews.llvm.org/D38614

llvm-svn: 315073
2017-10-06 16:15:59 +00:00
George Rimar 8f3a6c8143 [ELF] - Do not produce broken .dynamic section with --no-rosegment
LLD produces broken .dynamic section when --no-rosegment and at least
one of following options is present:
  1) -z rodynamic is given.
  2) MIPS target.

That happens because code that writes .dynamic assumes target buffer
is zero-filled, what can be not true after LLD fills it with trap
instructions. With one of two options above, .dynamic becomes
SHF_ALLOC section, so can be affected.

Differential revision: https://reviews.llvm.org/D38580

llvm-svn: 315054
2017-10-06 10:06:13 +00:00
George Rimar 2727ce2c1f [ELF] - Do not produce broken .dynsym with --no-rosegment.
We produce broken output currently.
Code that writes .dynsym assumes output buffer is zero-filled,
though that is not always true. When --no-rosegment is given,
buffer can be filled with trap instructions. Patch fixes the issue.

It is relative with PR34705.

Differential revision: https://reviews.llvm.org/D38579

llvm-svn: 315053
2017-10-06 09:56:24 +00:00
George Rimar 148d75d8d5 [ELF] - Fix BB after r315051.
Testcase has "zlib" requirement, which is unsupported on
windows, so that it was not run locally for me.

llvm-svn: 315052
2017-10-06 09:46:04 +00:00
George Rimar d46753e421 [ELF] - Do --hash-style=both by default.
Its PR34712,

GNU linkers recently changed default values to "both" of "sysv".
Patch do the same for all targets except MIPS, where .gnu.hash
section is not yet supported.

Code suggested by Rui Ueyama.

Differential revision: https://reviews.llvm.org/D38407

llvm-svn: 315051
2017-10-06 09:37:44 +00:00
Rui Ueyama 0fda1d70bb Fix typo.
llvm-svn: 315042
2017-10-06 04:32:08 +00:00
Alexander Richardson 6651820a72 [ELF] Add missing REQUIRES: mips to the test added in r315035
llvm-svn: 315038
2017-10-05 23:48:29 +00:00
Alexander Richardson b9aa9a5500 [ELF] Don't crash when parsing a file with out-of-bounds version 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: 315036
2017-10-05 23:28:34 +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
Rui Ueyama 945cd64471 Wait for all threads to terminate before exitting.
I think it is not defined what would happen to detached threads
when the main thread tries to exit. That means it was not guaranteed
that unlinkAsync correctly removes a temporary file. It was also
reported that this unlinkAsync caused a crash on Windows.

This patch adds a few new functions so that the main thread always
waits for non-main threads before exitting.

I don't actually like the new two functions, runBackground and
waitForBackgroundThreads, because it looks like it is a bit
overdesigned. After all, what we are doing with these functions
is to just remove a file.

An alternative would be to do fork(2) and make the child process
remove a file asynchronously. However, it has its own problems.
Correctly forking and reclaiming a resource using waitpid(2) is not
doable unless we know our process-wide settings (such as signal mask),
but we can't make any assumption on it when lld is embedded to other
process. So I chose to stick with threads instead of multi-processes.

Differential Revision: https://reviews.llvm.org/D38571

llvm-svn: 315033
2017-10-05 23:01:11 +00:00
Rafael Espindola 4b851198fc Remove dead code.
llvm-svn: 314966
2017-10-05 03:01:05 +00:00
Rafael Espindola c29b24d524 Refactor duplicated code.
Since VisibleToRegularObj is weaker than LinkerRedefined, this should
have no functionality change.

llvm-svn: 314954
2017-10-05 00:35:47 +00:00
Rafael Espindola 0038dfa19d Revert "Revert r314810: Use sched_getaffinity instead of std:🧵:hardware_concurrency."
This reverts commit r314924.

The required llvm patch was recommitted.

llvm-svn: 314933
2017-10-04 20:35:05 +00:00
Rui Ueyama 61b9ce217a Revert r314810: Use sched_getaffinity instead of std:🧵:hardware_concurrency.
This reverts commit r314810 because r314809 was reverted.

llvm-svn: 314924
2017-10-04 18:39:51 +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
George Rimar ed906d8e63 [ELF] - Update after LLVM r314883 change. NFC.
llvm-svn: 314884
2017-10-04 08:50:34 +00:00
Rui Ueyama 7d1f5fd840 Call exitLld() from elf::link.
We used to call exitLld() from a leaf function, Writer::run(), because
we had objects on the stack whose dtors are expensive. Now we no longer
have such objects on the stack, so there's no reason to exist from the
leaf function.

llvm-svn: 314869
2017-10-04 00:50:11 +00:00
Shoaib Meenai e631c566e0 [ELF] Fix buildbots
Mark a test as requiring zlib.

llvm-svn: 314868
2017-10-04 00:38:14 +00:00
Rui Ueyama 732f4e2778 Remove BssSection::reserveSpace().
We no longer call reserveSpace more than once, so it can be merged with
its constructor.

llvm-svn: 314867
2017-10-04 00:21:17 +00:00
Shoaib Meenai 50d7b36f5e [ELF] Decompress debug info sections early
When reporting a symbol conflict, LLD parses the debug info to report
source location information. Sections have not been decompressed at this
point, so if an object file contains zlib compressed debug info, LLD
ends up passing this compressed debug info to the DWARF parser, which
causes debug info parsing failures and can trigger assertions in the
parser (as the test case demonstrates).

Decompress debug sections when constructing the LLDDwarfObj to avoid
this issue. This doesn't handle GNU-style compressed debug info sections
(.zdebug_*), which at present are simply ignored by LLDDwarfObj; those
can be done in a follow-up.

Differential Revision: https://reviews.llvm.org/D38491

llvm-svn: 314866
2017-10-04 00:19:41 +00:00
Rafael Espindola 9b1dea506f Add a note on where to get a lld benchmark.
llvm-svn: 314862
2017-10-03 23:44:24 +00:00
Rui Ueyama a215e7cbe8 Move fetchIfLazy up so that the following comment makes sense.
We have this comment in LinkerDriver::link

  After this, no new names except a few linker-synthesized ones
  will be added to the symbol table.

but that was not true because new symbols could be added by processing
the -u option.

llvm-svn: 314842
2017-10-03 20:45:09 +00:00
Rui Ueyama fa105f8deb Inline a small function.
llvm-svn: 314841
2017-10-03 20:44:54 +00:00
Hans Wennborg 6b1be121c0 Update test expectation after r314821
llvm-svn: 314827
2017-10-03 18:46:57 +00:00
Rafael Espindola c804bf9397 Use sched_getaffinity instead of std:🧵:hardware_concurrency.
The issue with std:🧵:hardware_concurrency is that it forwards
to libc and some implementations (like glibc) don't take thread
affinity into consideration.

With this change a llvm program that can execute in only 2 cores will
use 2 threads, even if the machine has 32 cores.

This makes benchmarking a lot easier, but should also help if someone
doesn't want to use all cores for compilation for example.

llvm-svn: 314810
2017-10-03 16:25:48 +00:00
Simon Atanasyan f8db45361e [MIPS] Generate thunks for microMIPS code
If symbol has the STO_MIPS_MICROMIPS flag and requires a thunk to perform
call PIC from non-PIC functions, we need to generate a thunk with microMIPS
code.

llvm-svn: 314797
2017-10-03 13:30:02 +00:00
Igor Kudrin fb7f8befec [ELF] Avoid promoting an undefined weak entry symbol to global.
Without this patch, lld emits "error: undefined symbol: _start"
if it encountered only weak references to that symbol.

llvm-svn: 314790
2017-10-03 12:23:46 +00:00