Commit Graph

342 Commits

Author SHA1 Message Date
Francis Visoiu Mistrih 1e252811d6 Reland "[Remarks] Add -foptimization-record-passes to filter remark emission"
Currently we have -Rpass for filtering the remarks that are displayed as
diagnostics, but when using -fsave-optimization-record, there is no way
to filter the remarks while generating them.

This adds support for filtering remarks by passes using a regex.
Ex: `clang -fsave-optimization-record -foptimization-record-passes=inline`

will only emit the remarks coming from the pass `inline`.

This adds:

* `-fsave-optimization-record` to the driver
* `-opt-record-passes` to cc1
* `-lto-pass-remarks-filter` to the LTOCodeGenerator
* `--opt-remarks-passes` to lld
* `-pass-remarks-filter` to llc, opt, llvm-lto, llvm-lto2
* `-opt-remarks-passes` to gold-plugin

Differential Revision: https://reviews.llvm.org/D59268

Original llvm-svn: 355964

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355984 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-12 21:22:27 +00:00
Francis Visoiu Mistrih a826459b5e Revert "[Remarks] Add -foptimization-record-passes to filter remark emission"
This reverts commit 20fff32b7d1f1a1bd417b22aa9f26ededd97a3e5.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355976 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-12 20:54:18 +00:00
Francis Visoiu Mistrih 1bd774409d [Remarks] Add -foptimization-record-passes to filter remark emission
Currently we have -Rpass for filtering the remarks that are displayed as
diagnostics, but when using -fsave-optimization-record, there is no way
to filter the remarks while generating them.

This adds support for filtering remarks by passes using a regex.
Ex: `clang -fsave-optimization-record -foptimization-record-passes=inline`

will only emit the remarks coming from the pass `inline`.

This adds:

* `-fsave-optimization-record` to the driver
* `-opt-record-passes` to cc1
* `-lto-pass-remarks-filter` to the LTOCodeGenerator
* `--opt-remarks-passes` to lld
* `-pass-remarks-filter` to llc, opt, llvm-lto, llvm-lto2
* `-opt-remarks-passes` to gold-plugin

Differential Revision: https://reviews.llvm.org/D59268

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355964 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-12 20:28:50 +00:00
Rong Xu 09ad125e8c Recommit r354930 "[PGO] Context sensitive PGO (part 1)"
Fixed UBSan failures.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355005 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-27 17:24:33 +00:00
Vlad Tsyrklevich d97a419cbe Revert "[PGO] Context sensitive PGO (part 1)"
This reverts commit r354930, it was causing UBSan failures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354953 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-27 03:45:28 +00:00
Rong Xu a764eb906a [PGO] Context sensitive PGO (part 1)
Current PGO profile counts are not context sensitive. The branch probabilities
for the inlined functions are kept the same for all call-sites, and they might
be very different from the actual branch probabilities. These suboptimal
profiles can greatly affect some downstream optimizations, in particular for
the machine basic block placement optimization.

In this patch, we propose to have a post-inline PGO instrumentation/use pass,
which we called Context Sensitive PGO (CSPGO). For the users who want the best
possible performance, they can perform a second round of PGO instrument/use on
the top of the regular PGO. They will have two sets of profile counts. The
first pass profile will be manly for inline, indirect-call promotion, and
CGSCC simplification pass optimizations. The second pass profile is for
post-inline optimizations and code-gen optimizations.

A typical usage:
// Regular PGO instrumentation and generate pass1 profile.
> clang -O2 -fprofile-generate source.c -o gen
> ./gen
> llvm-profdata merge default.*profraw -o pass1.profdata
// CSPGO instrumentation.
> clang -O2 -fprofile-use=pass1.profdata -fcs-profile-generate -o gen2
> ./gen2
// Merge two sets of profiles
> llvm-profdata merge default.*profraw pass1.profdata -o profile.profdata
// Use the combined profile. Pass manager will invoke two PGO use passes.
> clang -O2 -fprofile-use=profile.profdata -o use

This change touches many components in the compiler. The reviewed patch
(D54175) will committed in phrases.

Differential Revision: https://reviews.llvm.org/D54175


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354930 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-26 22:37:46 +00:00
Chandler Carruth 6b547686c5 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 08:50:56 +00:00
Teresa Johnson 02e82c3508 [gold] emit assembly listing from gold plugin on LTO stage
Summary:
Sometimes it's useful to emit assembly after LTO stage to modify it manually. Emitting precodegen bitcode file (via save-temps plugin option) and then feeding it to llc doesn't always give the same binary as original.
This patch is simpler alternative to https://reviews.llvm.org/D24020.

Patch by Denis Bakhvalov.

Reviewers: mehdi_amini, tejohnson

Reviewed By: tejohnson

Subscribers: MaskRay, inglorion, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D56114

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350276 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-02 23:48:00 +00:00
Nick Desaulniers 0fca1c8158 [gold-plugin] allow function/data sections to be toggleable
Summary:
r336838 allowed these to be toggleable.
r336858 reverted r336838.
r336943 made the generation of these sections conditional on LDPO_REL.

This commit brings back the toggle-ability.  You can specify:
-plugin-opt=-function-sections
-plugin-opt=-data-sections
For your linker flags to disable the changes made in r336943.

Without toggling r336943 off, arm64 linux kernels linked with gold-plugin
see significant boot time regressions, but with r336943 outright reverted
x86_64 linux kernels linked with gold-plugin fail to boot.

Reviewers: pcc, void

Reviewed By: pcc

Subscribers: javed.absar, kristof.beyls, llvm-commits, srhines

Differential Revision: https://reviews.llvm.org/D55291

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@348389 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-05 17:46:24 +00:00
Mandeep Singh Grang badd06e25e [gold-plugin] Fix a bunch of build warnings
Phabricator: https://reviews.llvm.org/D53997

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345910 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-01 23:34:12 +00:00
Reid Kleckner 1e74971827 Silence -Wimplicit-fallthrough in gold plugin
Fatal errors are likely fatal, but in case they aren't, return instead
of printing a second warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345894 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-01 21:24:33 +00:00
Fangrui Song 1f25117d13 [gold] -thinlto-object-suffix-replace: don't append new suffix if path does not end with old suffix
Summary: This is to be consistent with lld behavior since rLLD340364.

Reviewers: tejohnson

Reviewed By: tejohnson

Subscribers: steven_wu, eraman, mehdi_amini, inglorion, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D51060

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340380 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-22 02:11:36 +00:00
Bill Wendling 0a4671b355 [gold-plugin] Disable section ordering for relocatable links
Not all programs want section ordering when compiled with LTO.
In particular, the Linux kernel is very sensitive when it comes to linking, and
doesn't boot when each function is placed in its own sections.

Reviewed By: pcc

Differential Revision: https://reviews.llvm.org/D48756


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336943 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-12 20:35:58 +00:00
Bill Wendling 1935f94438 Temporarily reverting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336858 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-11 21:47:55 +00:00
Bill Wendling 35e8f7fa33 gold: Add ability to toggle function/data sections
Some programs (e.g. Linux) aren't able to handle function/data sections when
LTO is used. Thus they need a way to disable it. That can be done with these
plugin options:

    -plugin-opt=-function-sections=0
    -plugin-opt=-data-sections=0


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336838 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-11 19:13:26 +00:00
Bill Wendling 6c008761fa Set the code model when specified.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334571 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-13 05:53:59 +00:00
Zachary Turner b99ddeab54 Try to fix build.
I don't know how to build this code, but based on the failing
buildbot error message it looks like this change should get
the buildbot up and running again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334231 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-07 20:37:22 +00:00
Teresa Johnson e07c2606ba [ThinLTO] Rename index IsAnalysis flag to HaveGVs (NFC)
With the upcoming patch to add summary parsing support, IsAnalysis would
be true in contexts where we are not performing module summary analysis.
Rename to the more specific and approprate HaveGVs, which is essentially
what this flag is indicating.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334140 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-06 22:22:01 +00:00
Peter Collingbourne aadeae8d7a LTO: Replace split dwarf implementation that uses objcopy with one that uses direct emission.
Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47091

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332884 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-21 20:26:49 +00:00
Florian Hahn a2fbfc91ac [LTO] Add stats-file option to LTO/Config.h.
This patch adds a StatsFile option to LTO/Config.h and updates both
LLVMGold and llvm-lto2 to set it.

Reviewers: MatzeB, tejohnson, espindola

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D45531


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330411 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-20 10:18:36 +00:00
Teresa Johnson 3e0bad65f9 [gold/ThinLTO] Invoke llvm_shutdown when exiting after ThinLTO indexing
Summary:
Instead of manually invoking PrintStatistics, simply invoke
llvm_shutdown which will take care of destroying managed statics, and as
a side effect will destroy the StatisticInfo ManagedStatic, invoking
PrintStatistics when needed.

Reviewers: fhahn

Subscribers: inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D45820

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330341 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-19 16:55:13 +00:00
Teresa Johnson 48ba666825 [gold] Add support for optimization remarks
Summary:
Adds support for LTO opt remarks (optionally with hotness) to
gold-plugin.

Reviewers: anemet

Subscribers: fhahn, mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D45752

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330252 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-18 13:25:23 +00:00
Yunlian Jiang edd00e40e6 Enable debug fission for thinLTO linked via gold-plugin
Summary: This enables debug fission on implicit ThinLTO when linked with gold. It will put the .dwo files in a directory specified by user. 

Reviewers: tejohnson, pcc, dblaikie

Reviewed By: pcc

Subscribers: JDevlieghere, mehdi_amini, inglorion

Differential Revision: https://reviews.llvm.org/D44792

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329988 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-13 05:03:28 +00:00
David Blaikie 461bf527e5 Rename *CommandFlags.def to *CommandFlags.inc
These aren't the .def style files used in LLVM that require a macro
defined before their inclusion - they're just basic non-modular includes
to stamp out command line flag variables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329840 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-11 18:49:37 +00:00
Peter Collingbourne 7edf726dc3 Revert r324557, "gold-plugin: Do not set codegen opt level based on LTO opt level."
It was reported that this change measurably regressed -plugin-opt=O3
performance.

There is an ongoing discussion on llvm-dev about the correct way to
set the CG opt level, see thread "[llvm-dev] [RFC] Adding function
attributes to represent codegen optimization level".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329458 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-06 21:14:33 +00:00
Teresa Johnson 65834ee9b5 [gold] Add debug-pass-manager option, and use it to test new-pass-manager
Summary: Follow up from r314963.

Reviewers: pcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45293

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329249 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-05 03:16:57 +00:00
Teresa Johnson 64c4f712b2 [LTO/gold] Fix workaround for old plugin-api.h in --wrap support
The workaround for older plugin-api.h in r327506 unfortunately
used another union member that is also fairly new and not available
in the plugin-api.h on some of the bots, leading to:
http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/9121/steps/build-stage2-LLVMgold.so/logs/stdio

Change to use a different member that we will definitely have (as it
is used elsewhere in gold-plugin.cpp already).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327509 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-14 14:00:57 +00:00
Teresa Johnson ead876539d [LTO/gold] Support --wrap
Summary:
(Restores r327459 with handling for old plugin-api.h)
Utilize new gold plugin api interface for obtaining --wrap option
arguments, and LTO API handling (added for --wrap support in lld LTO),
to mark symbols so that LTO does not optimize them inappropriately.

Note the test cases will be in a new gold test subdirectory that
is dependent on the next release of gold which will contain the new
interfaces.

Reviewers: pcc, tmsriram

Subscribers: mehdi_amini, llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D44235

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327506 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-14 13:26:18 +00:00
Teresa Johnson 8f15c882eb Revert "[LTO/gold] Support --wrap"
This reverts commit r327459. The new gold plugin interface is not
available with older gold installations, leading to compile failures:
http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/9109/steps/build-stage2-LLVMgold.so/logs/stdio

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327465 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-13 23:55:34 +00:00
Teresa Johnson a3a491bfb1 [LTO/gold] Support --wrap
Summary:
Utilize new gold plugin api interface for obtaining --wrap option
arguments, and LTO API handling (added for --wrap support in lld LTO),
to mark symbols so that LTO does not optimize them inappropriately.

Note the test cases will be in a new gold test subdirectory that
is dependent on the next release of gold which will contain the new
interfaces.

Reviewers: pcc, tmsriram

Subscribers: mehdi_amini, llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D44235

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327459 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-13 23:06:19 +00:00
Teresa Johnson 327fc51147 [ThinLTO/gold] Perform cache pruning when cache directory specified
Summary:
As pointed out in the review for D37993, for consistency with other
linkers, gold plugin should perform cache pruning whenever there is a
cache directory specified, which will use the default cache policy.

Reviewers: pcc

Subscribers: llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D43389

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325830 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-22 20:57:05 +00:00
Vitaly Buka 55523deb41 [ThinLTO] Always create linked objects file for --thinlto-index-only=
Summary:
ThinLTO indexing may decide to skip all objects. If we don't write something to
the list build system may consider this as failure or linker can reuse a file
from the previews build.

Reviewers: pcc, tejohnson

Subscribers: mehdi_amini, inglorion, eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D43415

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325819 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-22 19:06:15 +00:00
Vitaly Buka f662ded3c6 [gold] Extract runLTO to avoid exit(0) from function with non-trivial objects on the stack
Reviewers: tejohnson, pcc

Subscribers: inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D43537

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325818 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-22 19:06:05 +00:00
Teresa Johnson 761281e668 [LTO] Remove unused Path parameter to AddBufferFn
Summary:
With D43396, no clients use the Path parameter anymore.

Depends on D43396.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D43400

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325619 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-20 20:21:53 +00:00
Teresa Johnson f4aea13188 [ThinLTO/gold] Avoid race with cache pruner by copying to temp files
Summary:
This will avoid the race condition described in the review for D37993.

I believe that the Path parameter to AddBufferFn is no longer utilized.
I would prefer to remove that as a follow up clean up patch to reduce
the diffs in this patch.

Reviewers: pcc

Reviewed By: pcc

Subscribers: inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D43396

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325618 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-20 19:51:30 +00:00
Vitaly Buka 2749eb2cdf [ThinLTO] Allow indexing to request backend to ignore the module
Summary:
Gold plugin does not add pass to ThinLTO modules without useful symbols.
In this case ThinLTO can't create corresponding index file and some features, like CFI,
cannot be processes by backed correctly without index.
Given that we don't need the backed output we can request it to avoid
processing the module. This is implemented by this patch using new
"SkipModuleByDistributedBackend" flag.

Reviewers: pcc, tejohnson

Subscribers: mehdi_amini, inglorion, eraman, cfe-commits

Differential Revision: https://reviews.llvm.org/D42995

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325411 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-16 23:38:22 +00:00
Rafael Espindola 06d6207c1c Pass a reference to a module to the bitcode writer.
This simplifies most callers as they are already using references or
std::unique_ptr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325155 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-14 19:11:32 +00:00
Peter Collingbourne b07c392c11 gold-plugin: Do not set codegen opt level based on LTO opt level.
The LTO opt level should not affect the codegen opt level, and indeed
it does not affect it in lld. Ideally the codegen opt level should
be controlled by an IR-level attribute based on the compile-time opt
level, but that hasn't been implemented yet.

Differential Revision: https://reviews.llvm.org/D43040

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324557 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-08 02:41:22 +00:00
Vitaly Buka 23f8193f02 [ThinLTO/gold] Write empty imports even for modules with symbols
Summary: ThinLTO may skip object for other reasons, e.g. if there is no summary.

Reviewers: pcc, eugenis

Subscribers: mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D42514

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323818 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-30 21:19:26 +00:00
Eugene Leviant 72044ef693 [LLVMgold] Don't set undefined symbol as prevailing
Differential revision: https://reviews.llvm.org/D41113


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320794 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-15 09:18:21 +00:00
David Blaikie d7eaf516d4 Rename CommandFlags.h -> CommandFlags.def
Since this isn't a real header - it includes static functions and had
external linkage variables (though this change makes them static, since
that's what they should be) so can't be included more than once in a
program.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319082 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-27 19:43:58 +00:00
Sean Fertile abd8a85848 Enabling new pass manager in LTO (and thinLTO) link step.
Adds the option 'new-pass-manager' to the gold pluggin to enable using the
new pass manager during the lto/thinlto link step.

Patch by Graham Yiu.

 Differential Revision: https://reviews.llvm.org/D38517

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314963 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-05 01:48:42 +00:00
George Rimar c7c50afdca [gold-plugin] - Fix compilation after LLVM update (r314883). NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314899 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-04 11:00:30 +00:00
Yi Kong 74ae606cb2 [ThinLTO/gold] Implement ThinLTO cache pruning support
Differential Revision: https://reviews.llvm.org/D37993

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313592 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-18 23:24:55 +00:00
Peter Collingbourne a3886c11ee LTO: Try to open cache files before renaming them.
It appears that a potential race between the cache client and the cache
pruner that I thought was unlikely actually happened in practice [1].
Try to avoid the race condition by opening the temporary file before
renaming it. Do this only on non-Windows platforms because we cannot
rename open files on Windows using the sys::fs::rename function.

[1] https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.memory%2FLinux_CFI%2F1610%2F%2B%2Frecipes%2Fsteps%2Fcompile%2F0%2Fstdout

Differential Revision: https://reviews.llvm.org/D37410

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312567 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-05 19:51:38 +00:00
Benjamin Kramer e5d9cb587c [gold-plugin] Use more StringRef. No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310652 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-10 19:28:00 +00:00
Benjamin Kramer 01823a62a4 [gold-plugin] Avoid race condition when creating temporary files.
This is both a potential security issue and a potential functionality
issue because we create temporary files from multiple threads. Use
the safe version of createTemporaryFile instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310636 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-10 17:38:41 +00:00
Davide Italiano f34b3b16e3 [gold] Enable data-sections by default for the gold-plugin.
Follow up to r309056.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309075 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-26 01:47:17 +00:00
Davide Italiano 67d8465a23 [gold] Enable function-sections by default.
This is needed, among others, to respect --section-ordering-file
with LTO. I'll follow up with a similar change for data sections.

I hope every version of gold available on the bots has support for
--section-ordering file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309056 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-25 23:32:50 +00:00
Teresa Johnson a63ab3c9ea [LTO] Prevent dead stripping and internalization of symbols with sections
Summary:
ELF linkers generate __start_<secname> and __stop_<secname> symbols
when there is a value in a section <secname> where the name is a valid
C identifier.  If dead stripping determines that the values declared
in section <secname> are dead, and we then internalize (and delete)
such a symbol, programs that reference the corresponding start and end
section symbols will get undefined reference linking errors.

To fix this, add the section name to the IRSymtab entry when a symbol is
defined in a specific section. Then use this in the gold-plugin to mark
the symbol as external and visible from outside the summary when the
section name is a valid C identifier.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D35639

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309009 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-25 19:42:32 +00:00