Commit Graph

1680 Commits

Author SHA1 Message Date
Reid Kleckner 859f8b544a Make getParamAlignment use argument numbers
The method is called "get *Param* Alignment", and is only used for
return values exactly once, so it should take argument indices, not
attribute indices.

Avoids confusing code like:
  IsSwiftError = CS->paramHasAttr(ArgIdx, Attribute::SwiftError);
  Alignment  = CS->getParamAlignment(ArgIdx + 1);

Add getRetAlignment to handle the one case in Value.cpp that wants the
return value alignment.

This is a potentially breaking change for out-of-tree backends that do
their own call lowering.

llvm-svn: 301682
2017-04-28 20:34:27 +00:00
Adrian Prantl 109b236850 Clean up DIExpression::prependDIExpr a little. (NFC)
llvm-svn: 301662
2017-04-28 17:51:05 +00:00
Teresa Johnson 51177295c4 Memory intrinsic value profile optimization: Avoid divide by 0
Summary:
Skip memops if the total value profiled count is 0, we can't correctly
scale up the counts and there is no point anyway.

Reviewers: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32624

llvm-svn: 301645
2017-04-28 14:30:54 +00:00
Evgeniy Stepanov 964f4663c4 [asan] Fix dead stripping of globals on Linux.
Use a combination of !associated, comdat, @llvm.compiler.used and
custom sections to allow dead stripping of globals and their asan
metadata. Sometimes.

Currently this works on LLD, which supports SHF_LINK_ORDER with
sh_link pointing to the associated section.

This also works on BFD, which seems to treat comdats as
all-or-nothing with respect to linker GC. There is a weird quirk
where the "first" global in each link is never GC-ed because of the
section symbols.

At this moment it does not work on Gold (as in the globals are never
stripped).

This is a second re-land of r298158. This time, this feature is
limited to -fdata-sections builds.

llvm-svn: 301587
2017-04-27 20:27:27 +00:00
Evgeniy Stepanov 716f0ff222 [asan] Put ctor/dtor in comdat.
When possible, put ASan ctor/dtor in comdat.

The only reason not to is global registration, which can be
TU-specific. This is not the case when there are no instrumented
globals. This is also limited to ELF targets, because MachO does
not have comdat, and COFF linkers may GC comdat constructors.

The benefit of this is a lot less __asan_init() calls: one per DSO
instead of one per TU. It's also necessary for the upcoming
gc-sections-for-globals change on Linux, where multiple references to
section start symbols trigger quadratic behaviour in gold linker.

This is a second re-land of r298756. This time with a flag to disable
the whole thing to avoid a bug in the gold linker:
  https://sourceware.org/bugzilla/show_bug.cgi?id=19002

llvm-svn: 301586
2017-04-27 20:27:23 +00:00
Teresa Johnson f9ea176f05 Memory intrinsic value profile optimization: Improve debug output (NFC)
Summary:
Misc improvements to debug output. Fix a couple typos and also dump the
value profile before we make any profitability checks.

Reviewers: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32607

llvm-svn: 301574
2017-04-27 18:25:22 +00:00
Teresa Johnson b2c390e9f5 Update profile during memory instrinsic optimization
Summary:
Ensure that the new merge BB (which contains the rest of the original BB
after the mem op being optimized) gets a profile frequency, in case
there are additional mem ops later in the BB. Otherwise they get skipped
as the merge BB looks cold.

Reviewers: davidxl, xur

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32447

llvm-svn: 301244
2017-04-24 20:30:42 +00:00
Evgeniy Stepanov 9e536081fe [asan] Let the frontend disable gc-sections optimization for asan globals.
Also extend -asan-globals-live-support flag to all binary formats.

llvm-svn: 301226
2017-04-24 19:34:13 +00:00
Kostya Serebryany c5d3d49034 [sanitizer-coverage] remove some more stale code
llvm-svn: 300778
2017-04-19 22:42:11 +00:00
Evgeniy Stepanov 7c9b086ef5 Remove two unused variables (-Werror).
llvm-svn: 300777
2017-04-19 22:27:23 +00:00
Kostya Serebryany be87d480ff [sanitizer-coverage] remove stale code
llvm-svn: 300769
2017-04-19 21:48:09 +00:00
Adrian Prantl 6825fb64e9 PR32382: Fix emitting complex DWARF expressions.
The DWARF specification knows 3 kinds of non-empty simple location
descriptions:
1. Register location descriptions
  - describe a variable in a register
  - consist of only a DW_OP_reg
2. Memory location descriptions
  - describe the address of a variable
3. Implicit location descriptions
  - describe the value of a variable
  - end with DW_OP_stack_value & friends

The existing DwarfExpression code is pretty much ignorant of these
restrictions. This used to not matter because we only emitted very
short expressions that we happened to get right by accident.  This
patch makes DwarfExpression aware of the rules defined by the DWARF
standard and now chooses the right kind of location description for
each expression being emitted.

This would have been an NFC commit (for the existing testsuite) if not
for the way that clang describes captured block variables. Based on
how the previous code in LLVM emitted locations, DW_OP_deref
operations that should have come at the end of the expression are put
at its beginning. Fixing this means changing the semantics of
DIExpression, so this patch bumps the version number of DIExpression
and implements a bitcode upgrade.

There are two major changes in this patch:

I had to fix the semantics of dbg.declare for describing function
arguments. After this patch a dbg.declare always takes the *address*
of a variable as the first argument, even if the argument is not an
alloca.

When lowering a DBG_VALUE, the decision of whether to emit a register
location description or a memory location description depends on the
MachineLocation — register machine locations may get promoted to
memory locations based on their DIExpression. (Future) optimization
passes that want to salvage implicit debug location for variables may
do so by appending a DW_OP_stack_value. For example:
  DBG_VALUE, [RBP-8]                        --> DW_OP_fbreg -8
  DBG_VALUE, RAX                            --> DW_OP_reg0 +0
  DBG_VALUE, RAX, DIExpression(DW_OP_deref) --> DW_OP_reg0 +0

All testcases that were modified were regenerated from clang. I also
added source-based testcases for each of these to the debuginfo-tests
repository over the last week to make sure that no synchronized bugs
slip in. The debuginfo-tests compile from source and run the debugger.

https://bugs.llvm.org/show_bug.cgi?id=32382
<rdar://problem/31205000>

Differential Revision: https://reviews.llvm.org/D31439

llvm-svn: 300522
2017-04-18 01:21:53 +00:00
Vedant Kumar 1a6a2b642b [ProfileData] Unify getInstrProf*SectionName helpers
This is a version of D32090 that unifies all of the
`getInstrProf*SectionName` helper functions. (Note: the build failures
which D32090 would have addressed were fixed with r300352.)

We should unify these helper functions because they are hard to use in
their current form. E.g we recently introduced more helpers to fix
section naming for COFF files. This scheme doesn't totally succeed at
hiding low-level details about section naming, so we should switch to an
API that is easier to maintain.

This is not an NFC commit because it fixes llvm-cov's testing support
for COFF files (this falls out of the API change naturally). This is an
area where we lack tests -- I will see about adding one as a follow up.

Testing: check-clang, check-profile, check-llvm.

Differential Revision: https://reviews.llvm.org/D32097

llvm-svn: 300381
2017-04-15 00:09:57 +00:00
Reid Kleckner fb502d2f5e [IR] Make paramHasAttr to use arg indices instead of attr indices
This avoids the confusing 'CS.paramHasAttr(ArgNo + 1, Foo)' pattern.

Previously we were testing return value attributes with index 0, so I
introduced hasReturnAttr() for that use case.

llvm-svn: 300367
2017-04-14 20:19:02 +00:00
Xinliang David Li 9a71766751 Fix test failure on windows: pass module to getInstrProfXXName calls
llvm-svn: 300302
2017-04-14 03:03:24 +00:00
Xinliang David Li 57dea2d359 [Profile] PE binary coverage bug fix
PR/32584

Differential Revision: https://reviews.llvm.org/D32023

llvm-svn: 300277
2017-04-13 23:37:12 +00:00
Evgeniy Stepanov 90fd87303c [asan] Give global metadata private linkage.
Internal linkage preserves names like "__asan_global_foo" which may
account to 2% of unstripped binary size.

llvm-svn: 299995
2017-04-11 22:28:13 +00:00
Serge Guelton 59a2d7b909 Module::getOrInsertFunction is using C-style vararg instead of variadic templates.
From a user prospective, it forces the use of an annoying nullptr to mark the end of the vararg, and there's not type checking on the arguments.
The variadic template is an obvious solution to both issues.

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299949
2017-04-11 15:01:18 +00:00
Diana Picus b050c7fbe0 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299925 because it broke the buildbots. See e.g.
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/6008

llvm-svn: 299928
2017-04-11 10:07:12 +00:00
Serge Guelton 5fd75fb72e Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

llvm-svn: 299925
2017-04-11 08:36:52 +00:00
Matt Arsenault 3c1fc768ed Allow DataLayout to specify addrspace for allocas.
LLVM makes several assumptions about address space 0. However,
alloca is presently constrained to always return this address space.
There's no real way to avoid using alloca, so without this
there is no way to opt out of these assumptions.

The problematic assumptions include:
- That the pointer size used for the stack is the same size as
  the code size pointer, which is also the maximum sized pointer.

- That 0 is an invalid, non-dereferencable pointer value.

These are problems for AMDGPU because alloca is used to
implement the private address space, which uses a 32-bit
index as the pointer value. Other pointers are 64-bit
and behave more like LLVM's notion of generic address
space. By changing the address space used for allocas,
we can change our generic pointer type to be LLVM's generic
pointer type which does have similar properties.

llvm-svn: 299888
2017-04-10 22:27:50 +00:00
Evgeniy Stepanov ed7fce7c84 Revert "[asan] Put ctor/dtor in comdat."
This reverts commit r299696, which is causing mysterious test failures.

llvm-svn: 299880
2017-04-10 20:36:36 +00:00
Evgeniy Stepanov ba7c2e9661 Revert "[asan] Fix dead stripping of globals on Linux."
This reverts commit r299697, which caused a big increase in object file size.

llvm-svn: 299879
2017-04-10 20:36:30 +00:00
Rong Xu 2bf4c59025 [PGO] Preserve GlobalsAA in pgo-memop-opt pass.
Preserve GlobalsAA analysis in memory intrinsic calls optimization based on
profiled size.

llvm-svn: 299707
2017-04-06 20:56:00 +00:00
Mehdi Amini db11fdfda5 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299699, the examples needs to be updated.

llvm-svn: 299702
2017-04-06 20:23:57 +00:00
Mehdi Amini 579540a8f7 Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

Patch by: Serge Guelton <serge.guelton@telecom-bretagne.eu>

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299699
2017-04-06 20:09:31 +00:00
Evgeniy Stepanov 6c3a8cbc4d [asan] Fix dead stripping of globals on Linux.
Use a combination of !associated, comdat, @llvm.compiler.used and
custom sections to allow dead stripping of globals and their asan
metadata. Sometimes.

Currently this works on LLD, which supports SHF_LINK_ORDER with
sh_link pointing to the associated section.

This also works on BFD, which seems to treat comdats as
all-or-nothing with respect to linker GC. There is a weird quirk
where the "first" global in each link is never GC-ed because of the
section symbols.

At this moment it does not work on Gold (as in the globals are never
stripped).

This is a re-land of r298158 rebased on D31358. This time,
asan.module_ctor is put in a comdat as well to avoid quadratic
behavior in Gold.

llvm-svn: 299697
2017-04-06 19:55:17 +00:00
Evgeniy Stepanov 5dfe420d10 [asan] Put ctor/dtor in comdat.
When possible, put ASan ctor/dtor in comdat.

The only reason not to is global registration, which can be
TU-specific. This is not the case when there are no instrumented
globals. This is also limited to ELF targets, because MachO does
not have comdat, and COFF linkers may GC comdat constructors.

The benefit of this is a lot less __asan_init() calls: one per DSO
instead of one per TU. It's also necessary for the upcoming
gc-sections-for-globals change on Linux, where multiple references to
section start symbols trigger quadratic behaviour in gold linker.

This is a rebase of r298756.

llvm-svn: 299696
2017-04-06 19:55:13 +00:00
Evgeniy Stepanov 039af609f1 [asan] Delay creation of asan ctor.
Create the constructor in the module pass.
This in needed for the GC-friendly globals change, where the constructor can be
put in a comdat  in some cases, but we don't know about that in the function
pass.

This is a rebase of r298731 which was reverted due to a false alarm.

llvm-svn: 299695
2017-04-06 19:55:09 +00:00
Rong Xu 48596b6f7a [PGO] Memory intrinsic calls optimization based on profiled size
This patch optimizes two memory intrinsic operations: memset and memcpy based
on the profiled size of the operation. The high level transformation is like:
  mem_op(..., size)
  ==>
  switch (size) {
    case s1:
       mem_op(..., s1);
       goto merge_bb;
    case s2:
       mem_op(..., s2);
       goto merge_bb;
    ...
    default:
       mem_op(..., size);
       goto merge_bb;
    }
  merge_bb:

Differential Revision: http://reviews.llvm.org/D28966

llvm-svn: 299446
2017-04-04 16:42:20 +00:00
Alex Shlyapnikov bbd5cc63d7 Revert "[asan] Delay creation of asan ctor."
Speculative revert. Some libfuzzer tests are affected.

This reverts commit r298731.

llvm-svn: 298890
2017-03-27 23:11:50 +00:00
Alex Shlyapnikov 09171aa31f Revert "[asan] Put ctor/dtor in comdat."
Speculative revert, some libfuzzer tests are affected.

This reverts commit r298756.

llvm-svn: 298889
2017-03-27 23:11:47 +00:00
Evgeniy Stepanov 71bb8f1ad0 [asan] Put ctor/dtor in comdat.
When possible, put ASan ctor/dtor in comdat.

The only reason not to is global registration, which can be
TU-specific. This is not the case when there are no instrumented
globals. This is also limited to ELF targets, because MachO does
not have comdat, and COFF linkers may GC comdat constructors.

The benefit of this is a lot less __asan_init() calls: one per DSO
instead of one per TU. It's also necessary for the upcoming
gc-sections-for-globals change on Linux, where multiple references to
section start symbols trigger quadratic behaviour in gold linker.

llvm-svn: 298756
2017-03-25 01:01:11 +00:00
Evgeniy Stepanov 64e872a91f [asan] Delay creation of asan ctor.
Create the constructor in the module pass.
This in needed for the GC-friendly globals change, where the constructor can be
put in a comdat  in some cases, but we don't know about that in the function
pass.

llvm-svn: 298731
2017-03-24 20:42:15 +00:00
Reid Kleckner 392f062675 [sancov] Don't instrument blocks with no insertion point
This prevents crashes when attempting to instrument functions containing
C++ try.

Sanitizer coverage will still fail at runtime when an exception is
thrown through a sancov instrumented function, but that seems marginally
better than what we have now. The full solution is to color the blocks
in LLVM IR and only instrument blocks that have an unambiguous color,
using the appropriate token.

llvm-svn: 298662
2017-03-23 23:30:41 +00:00
George Burgess IV 56c7e88c2c Let llvm.objectsize be conservative with null pointers
This adds a parameter to @llvm.objectsize that makes it return
conservative values if it's given null.

This fixes PR23277.

Differential Revision: https://reviews.llvm.org/D28494

llvm-svn: 298430
2017-03-21 20:08:59 +00:00
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Evgeniy Stepanov c440572715 Revert r298158.
Revert "[asan] Fix dead stripping of globals on Linux."

OOM in gold linker.

llvm-svn: 298288
2017-03-20 18:45:34 +00:00
Evgeniy Stepanov c5aa6b9411 [asan] Fix dead stripping of globals on Linux.
Use a combination of !associated, comdat, @llvm.compiler.used and
custom sections to allow dead stripping of globals and their asan
metadata. Sometimes.

Currently this works on LLD, which supports SHF_LINK_ORDER with
sh_link pointing to the associated section.

This also works on BFD, which seems to treat comdats as
all-or-nothing with respect to linker GC. There is a weird quirk
where the "first" global in each link is never GC-ed because of the
section symbols.

At this moment it does not work on Gold (as in the globals are never
stripped).

Differential Revision: https://reviews.llvm.org/D30121

llvm-svn: 298158
2017-03-17 22:17:29 +00:00
Vassil Vassilev c70a8f2df1 [coverity] Fix uninit variable.
Patch by John Harvey!

llvm-svn: 298122
2017-03-17 20:58:08 +00:00
Rong Xu 8e06e80b87 [PGO] Change the internal options description. nfc.
llvm-svn: 298120
2017-03-17 20:51:44 +00:00
Rong Xu e60343d6b0 [PGO] Value profile for size of memory intrinsic calls
This patch annotates the valuesites profile to memory intrinsics.

Differential Revision: http://reviews.llvm.org/D31002

llvm-svn: 298110
2017-03-17 18:07:26 +00:00
Reid Kleckner 45707d4d5a Remove getArgumentList() in favor of arg_begin(), args(), etc
Users often call getArgumentList().size(), which is a linear way to get
the number of function arguments. arg_size(), on the other hand, is
constant time.

In general, the fact that arguments are stored in an iplist is an
implementation detail, so I've removed it from the Function interface
and moved all other users to the argument container APIs (arg_begin(),
arg_end(), args(), arg_size()).

Reviewed By: chandlerc

Differential Revision: https://reviews.llvm.org/D31052

llvm-svn: 298010
2017-03-16 22:59:15 +00:00
Rong Xu 60faea19f8 Resubmit r297897: [PGO] Value profile for size of memory intrinsic calls
R297897 inadvertently enabled annotation for memop profiling. This new patch
fixed it.

llvm-svn: 297996
2017-03-16 21:15:48 +00:00
Eric Liu 971de62291 Revert "[PGO] Value profile for size of memory intrinsic calls"
This commit reverts r297897 and r297909.

llvm-svn: 297951
2017-03-16 13:16:35 +00:00
Vitaly Buka ca6ecd213a Revert "Revert "[PGO] Minor cleanup for count instruction in SelectInstVisitor.""
Previously reverted wrong revision.

This reverts commit r297910.

llvm-svn: 297911
2017-03-15 23:07:41 +00:00
Vitaly Buka de85ad895d Revert "[PGO] Minor cleanup for count instruction in SelectInstVisitor."
Fails LLVMFuzzer.LLVMFuzzer.value-profile-strncmp.test

This reverts commit r297892.

llvm-svn: 297910
2017-03-15 23:06:22 +00:00
Rong Xu 8acf76b6b9 Fix build failure from r297897.
llvm-svn: 297909
2017-03-15 23:00:19 +00:00
Rong Xu 4ed52798ce [PGO] Value profile for size of memory intrinsic calls
This patch adds the value profile support to profile the size parameter of
memory intrinsic calls: memcpy, memcmp, and memmov.

Differential Revision: http://reviews.llvm.org/D28965

llvm-svn: 297897
2017-03-15 21:47:27 +00:00
Rong Xu d709b0fe95 [PGO] Minor cleanup for count instruction in SelectInstVisitor.
Summary:
NSIs can be double-counted by different operations in
SelectInstVisitor. Sink the the update to VM_counting mode only.
Also reset the value for each counting operation.

Reviewers: davidxl

Reviewed By: davidxl

Subscribers: xur, llvm-commits

Differential Revision: https://reviews.llvm.org/D30999

llvm-svn: 297892
2017-03-15 21:05:24 +00:00
Rong Xu a3bbf96eba [PGO] Refactor the code for value profile annotation
This patch refactors the code for value profile annotation to facilitate
of adding other kind of value profiles.

Differential Revision: http://reviews.llvm.org/D30989

llvm-svn: 297870
2017-03-15 18:23:39 +00:00
Rong Xu 0a2a1311df Minor format change. nfc.
llvm-svn: 297400
2017-03-09 19:08:55 +00:00
Evgeniy Stepanov d0285f21d0 [msan] Handle x86_sse_stmxcsr and x86_sse_ldmxcsr.
llvm-svn: 296848
2017-03-03 01:12:43 +00:00
Evgeniy Stepanov c00e45eada [msan] Remove stale comments.
ClStoreCleanOrigin flag was removed back in 2014.

llvm-svn: 296844
2017-03-03 00:25:56 +00:00
Petr Hosek 6f16857167 [AddressSanitizer] Put shadow at 0 for Fuchsia
The Fuchsia ASan runtime reserves the low part of the address space.

Patch by Roland McGrath

Differential Revision: https://reviews.llvm.org/D30426

llvm-svn: 296405
2017-02-27 22:49:37 +00:00
Evgeniy Stepanov d1daf631f4 [msan] Fix instrumentation of array allocas.
Before this, MSan poisoned exactly one element of any array alloca,
even if the number of elements was zero.

llvm-svn: 296050
2017-02-24 00:13:17 +00:00
Dehao Chen cc75d2441d Add call branch annotation for ICP promoted direct call in SamplePGO mode.
Summary: SamplePGO uses branch_weight annotation to represent callsite hotness. When ICP promotes an indirect call to direct call, we need to make sure the direct call is annotated with branch_weight in SamplePGO mode, so that downstream function inliner can use hot callsite heuristic.

Reviewers: davidxl, eraman, xur

Reviewed By: davidxl, xur

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D30282

llvm-svn: 296028
2017-02-23 22:15:18 +00:00
Filipe Cabecinhas 33dd486f1d [AddressSanitizer] Add PS4 offset
llvm-svn: 295994
2017-02-23 17:10:28 +00:00
Arnold Schwaighofer 8d61e0030a AddressSanitizer: don't track swifterror memory addresses
They are register promoted by ISel and so it makes no sense to treat them as
memory.

Inserting calls to the thread sanitizer would also generate invalid IR.

You would hit:

"swifterror value can only be loaded and stored from, or as a swifterror
argument!"

llvm-svn: 295230
2017-02-15 20:43:43 +00:00
Arnold Schwaighofer 8eb1a48540 ThreadSanitizer: don't track swifterror memory addresses
They are register promoted by ISel and so it makes no sense to treat them as
memory.

Inserting calls to the thread sanitizer would also generate invalid IR.

You would hit:

"swifterror value can only be loaded and stored from, or as a swifterror
argument!"

llvm-svn: 295215
2017-02-15 18:57:06 +00:00
Vedant Kumar 55891fc71e Re-apply "[profiling] Remove dead profile name vars after emitting name data"
This reverts 295092 (re-applies 295084), with a fix for dangling
references from the array of coverage names passed down from frontends.

I missed this in my initial testing because I only checked test/Profile,
and not test/CoverageMapping as well.

Original commit message:

The profile name variables passed to counter increment intrinsics are dead
after we emit the finalized name data in __llvm_prf_nm. However, we neglect to
erase these name variables. This causes huge size increases in the
__TEXT,__const section as well as slowdowns when linker dead stripping is
disabled. Some affected projects are so massive that they fail to link on
Darwin, because only the small code model is supported.

Fix the issue by throwing away the name constants as soon as we're done with
them.

Differential Revision: https://reviews.llvm.org/D29921

llvm-svn: 295099
2017-02-14 20:03:48 +00:00
Vedant Kumar 27ebdf4bcb Revert "[profiling] Remove dead profile name vars after emitting name data"
This reverts commit r295084. There is a test failure on:

http://lab.llvm.org:8011/builders/clang-atom-d525-fedora-rel/builds/2620/

llvm-svn: 295092
2017-02-14 19:08:39 +00:00
Vedant Kumar bb10484662 [profiling] Remove dead profile name vars after emitting name data
The profile name variables passed to counter increment intrinsics are
dead after we emit the finalized name data in __llvm_prf_nm. However, we
neglect to erase these name variables. This causes huge size increases
in the __TEXT,__const section as well as slowdowns when linker dead
stripping is disabled. Some affected projects are so massive that they
fail to link on Darwin, because only the small code model is supported.

Fix the issue by throwing away the name constants as soon as we're done
with them.

Differential Revision: https://reviews.llvm.org/D29921

llvm-svn: 295084
2017-02-14 18:48:48 +00:00
Mike Aizatsky 4705ae936d [sancov] using comdat only when it is enabled
Differential Revision: https://reviews.llvm.org/D29733

llvm-svn: 294529
2017-02-08 23:12:46 +00:00
Mike Aizatsky 401d369328 [sancov] specifying comdat for sancov constructors
Differential Revision: https://reviews.llvm.org/D29662

llvm-svn: 294517
2017-02-08 21:20:33 +00:00
Xinliang David Li c7db0d0e75 Fix variable name /NFC
llvm-svn: 294090
2017-02-04 07:40:43 +00:00
Xinliang David Li 6144a59b7f [PGO] Add select instr profile in graph dump
Differential Revision: http://reviews.llvm.org/D29474

llvm-svn: 294055
2017-02-03 21:57:51 +00:00
Marcos Pividori db5a565514 [sanitizer coverage] Fix Instrumentation to work on Windows.
On Windows, the symbols "___stop___sancov_guards" and "___start___sancov_guards"
are not defined automatically. So, we need to take a different approach.
We define 3 sections:

 Section ".SCOV$A" will only hold a variable ___start___sancov_guard.
 Section ".SCOV$M" will hold the main data.
 Section ".SCOV$Z" will only hold a variable ___stop___sancov_guards.

When linking, they will be merged sorted by the characters after the $, so we
can use the pointers of the variables ___[start|stop]___sancov_guard to know the
actual range of addresses of that section.

In this diff, I updated instrumentation to include all the guard arrays in
section ".SCOV$M".

Differential Revision: https://reviews.llvm.org/D28434

llvm-svn: 293987
2017-02-03 01:08:06 +00:00
Xinliang David Li 58fcc9bdce [PGO] internal option cleanups
1. Added comments for options
2. Added missing option cl::desc field
3. Uniified function filter option for graph viewing.
   Now PGO count/raw-counts share the same
   filter option: -view-bfi-func-name=.

llvm-svn: 293938
2017-02-02 21:29:17 +00:00
Xinliang David Li 1eb4ec6a2e [PGO] make graph view internal options available for all builds
Differential Revision: https://reviews.llvm.org/D29259

llvm-svn: 293921
2017-02-02 19:18:56 +00:00
Justin Bogner 41e632bf6b SanitizerCoverage: Support sanitizer guard section on darwin
MachO's sections need a segment as well as a section name, and the
section start and end symbols are spelled differently than on ELF.

llvm-svn: 293733
2017-02-01 02:38:39 +00:00
Benjamin Kramer 365c9bd941 [ICP] Fix bool conversion warning and actually write out the reason instead of dropping it.
llvm-svn: 293564
2017-01-30 23:11:29 +00:00
Dehao Chen 6775f5d629 Expose isLegalToPromot as a global helper function so that SamplePGO pass can call it for legality check.
Summary: SamplePGO needs to check if it is legal to promote a target before it actually promotes it.

Reviewers: davidxl

Reviewed By: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29306

llvm-svn: 293559
2017-01-30 22:46:37 +00:00
Xinliang David Li d289e4541f [PGO] add debug option to view raw count after prof use annotation
Differential Revision: https://reviews.llvm.org/D29045

llvm-svn: 293325
2017-01-27 19:06:25 +00:00
Kostya Serebryany 4b2ff07c11 [sanitizer-coverage] emit __sanitizer_cov_trace_pc_guard w/o a preceding 'if' by default. Update the docs, also add deprecation notes around other parts of sanitizer coverage
llvm-svn: 292862
2017-01-24 00:57:31 +00:00
Dehao Chen 14bf029053 Makes promoteIndirectCall an external function.
Summary: promoteIndirectCall should be a utility function that could be invoked by other optimization passes.

Reviewers: davidxl

Reviewed By: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29051

llvm-svn: 292850
2017-01-23 23:18:24 +00:00
Xinliang David Li cb253ce90b [PGO] add debug option to view annotated cfg after prof use annotation
Differential Revision: http://reviews.llvm.org/D28967 

llvm-svn: 292815
2017-01-23 18:58:24 +00:00
Eugene Zelenko 34c23279c2 [Target, Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 292320
2017-01-18 00:57:48 +00:00
Dan Gohman 1209c7ac16 [WebAssembly] Add triple support for the new wasm object format
Differential Revision: https://reviews.llvm.org/D26701

llvm-svn: 292252
2017-01-17 20:34:09 +00:00
Evgeniy Stepanov f01c70fec0 [asan] Don't overalign global metadata.
Other than on COFF with incremental linking, global metadata should
not need any extra alignment.

Differential Revision: https://reviews.llvm.org/D28628

llvm-svn: 291859
2017-01-12 23:26:20 +00:00
Evgeniy Stepanov 5d31d08a21 [asan] Refactor instrumentation of globals.
llvm-svn: 291858
2017-01-12 23:03:03 +00:00
Kuba Mracek 503162b4a1 [asan] Set alignment of __asan_global_* globals to sizeof(GlobalStruct)
When using profiling and ASan together (-fprofile-instr-generate -fcoverage-mapping -fsanitize=address), at least on Darwin, the section of globals that ASan emits (__asan_globals) is misaligned and starts at an odd offset. This really doesn't have anything to do with profiling, but it triggers the issue because profiling emits a string section, which can have arbitrary size.  This patch changes the alignment to sizeof(GlobalStruct).

Differential Revision: https://reviews.llvm.org/D28573

llvm-svn: 291715
2017-01-11 22:26:10 +00:00
Rong Xu 20f5df1d70 Resubmit "[PGO] Turn off comdat renaming in IR PGO by default"
This patch resubmits the changes in r291588.

llvm-svn: 291696
2017-01-11 20:19:41 +00:00
Rong Xu acd6360251 Revert "[PGO] Turn off comdat renaming in IR PGO by default"
This patch reverts r291588: [PGO] Turn off comdat renaming in IR PGO by default,
as we are seeing some hash mismatches in our internal tests.

llvm-svn: 291621
2017-01-10 23:54:31 +00:00
Rong Xu ef1adad938 [PGO] Turn off comdat renaming in IR PGO by default
Summary:
In IR PGO we append the function hash to comdat functions to avoid the
potential hash mismatch. This turns out not legal in some cases: if the comdat
function is address-taken and used in comparison. Renaming changes the semantic.

This patch turns off comdat renaming by default.

To alleviate the hash mismatch issue, we now rename the profile variable
for comdat functions. Profile allows co-existing multiple versions of profiles
with different hash value. The inlined copy will always has the correct profile
counter. The out-of-line copy might not have the correct count. But we will
not have the bogus mismatch warning.

Reviewers: davidxl

Subscribers: llvm-commits, xur

Differential Revision: https://reviews.llvm.org/D28416

llvm-svn: 291588
2017-01-10 19:30:20 +00:00
Kuba Mracek 316dc70f82 [asan] Change the visibility of ___asan_globals_registered to hidden
This flag is used to track global registration in Mach-O and it doesn't need to be exported and visible.

Differential Revision: https://reviews.llvm.org/D28250

llvm-svn: 291289
2017-01-06 22:02:58 +00:00
Filipe Cabecinhas 4647b74b51 [ASan] Make ASan instrument variable-masked loads and stores
Summary: Previously we only supported constant-masked loads and stores.

Reviewers: kcc, RKSimon, pgousseau, gbedwell, vitalybuka

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28370

llvm-svn: 291238
2017-01-06 15:24:51 +00:00
Kostya Serebryany f24e52c0c2 [sanitizer-coverage] sort the switch cases
llvm-svn: 290628
2016-12-27 21:20:06 +00:00
Adrian Prantl bceaaa9643 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 290153
2016-12-20 02:09:43 +00:00
Adrian Prantl 73ec065604 Revert "[IR] Remove the DIExpression field from DIGlobalVariable."
This reverts commit 289920 (again).
I forgot to implement a Bitcode upgrade for the case where a DIGlobalVariable
has not DIExpression. Unfortunately it is not possible to safely upgrade
these variables without adding a flag to the bitcode record indicating which
version they are.
My plan of record is to roll the planned follow-up patch that adds a
unit: field to DIGlobalVariable into this patch before recomitting.
This way we only need one Bitcode upgrade for both changes (with a
version flag in the bitcode record to safely distinguish the record
formats).

Sorry for the churn!

llvm-svn: 289982
2016-12-16 19:39:01 +00:00
Adrian Prantl 74a835cda0 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 289920
2016-12-16 04:25:54 +00:00
Adrian Prantl 03c6d31a3b Revert "[IR] Remove the DIExpression field from DIGlobalVariable."
This reverts commit 289902 while investigating bot berakage.

llvm-svn: 289906
2016-12-16 01:00:30 +00:00
Adrian Prantl ce13935776 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 289902
2016-12-16 00:36:43 +00:00
Filipe Cabecinhas dd9688703c [asan] Don't skip instrumentation of masked load/store unless we've seen a full load/store on that pointer.
Reviewers: kcc, RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D27625

llvm-svn: 289718
2016-12-14 21:57:04 +00:00
Filipe Cabecinhas 1e69017a6d [asan] Hook ClInstrumentWrites and ClInstrumentReads to masked operation instrumentation.
Reviewers: kcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D27548

llvm-svn: 289717
2016-12-14 21:56:59 +00:00
Rong Xu 51a1e3c430 [PGO] Fix insane counts due to nonreturn calls
Summary:
Since we don't break BBs for function calls. We might get some insane counts 
(wrap of unsigned) in the presence of noreturn calls.

This patch sets these counts to zero instead of the wrapped number.

Reviewers: davidxl

Subscribers: xur, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D27602

llvm-svn: 289521
2016-12-13 06:41:14 +00:00
Kostya Serebryany 520753a321 [sanitizer-coverage] use IRB.SetCurrentDebugLocation after IRB.SetInsertPoint
llvm-svn: 288568
2016-12-03 01:43:30 +00:00
Rong Xu a5b5745a62 [PGO] Fix PGO use ICE when there are unreachable BBs
For -O0 there might be unreachable BBs, which breaks the assumption that all the
BBs have an auxiliary data structure.  In this patch, we add another interface
called findBBInfo() so that a nullptr can be returned for the unreachable BBs
(and the callers can ignore those BBs).

This fixes the bug reported
https://llvm.org/bugs/show_bug.cgi?id=31209

Differential Revision: https://reviews.llvm.org/D27280

llvm-svn: 288528
2016-12-02 19:10:29 +00:00
Reid Kleckner 78565839c6 [asan/win] Align global registration metadata to its size
This way, when the linker adds padding between globals, we can skip over
the zero padding bytes and reliably find the start of the next metadata
global.

llvm-svn: 288096
2016-11-29 01:32:21 +00:00
Reid Kleckner 01660a3d2a [asan] Make ASan compatible with linker dead stripping on Windows
Summary:
This is similar to what was done for Darwin in rL264645 /
http://reviews.llvm.org/D16737, but it uses COFF COMDATs to achive the
same result instead of relying on new custom linker features.

As on MachO, this creates one metadata global per instrumented global.
The metadata global is placed in the custom .ASAN$GL section, which the
ASan runtime will iterate over during initialization. There are no other
references to the metadata, so normal linker dead stripping would
discard it. However, the metadata is put in a COMDAT group with the
instrumented global, so that it will be discarded if and only if the
instrumented global is discarded.

I didn't update the ASan ABI version check since this doesn't affect
non-Windows platforms, and the WinASan ABI isn't really stable yet.

Implementing this for ELF will require extending LLVM IR and MC a bit so
that we can use non-COMDAT section groups.

Reviewers: pcc, kcc, mehdi_amini, kubabrecka

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26770

llvm-svn: 287576
2016-11-21 20:40:37 +00:00
Marcin Koscielnicki 1c2bd1e9f3 [InstrProfiling] Mark __llvm_profile_instrument_target last parameter as i32 zeroext if appropriate.
On some architectures (s390x, ppc64, sparc64, mips), C-level int is passed
as i32 signext instead of plain i32.  Likewise, unsigned int may be passed
as i32, i32 signext, or i32 zeroext depending on the platform.  Mark
__llvm_profile_instrument_target properly (its last parameter is unsigned
int).

This (together with the clang change) makes compiler-rt profile testsuite pass
on s390x.

Differential Revision: http://reviews.llvm.org/D21736

llvm-svn: 287534
2016-11-21 11:57:19 +00:00
Anna Zaks 9cd5ed1241 [asan] Turn on Mach-O global metadata liveness tracking by default
This patch turns on the metadata liveness tracking since all known issues
have been resolved. The future has been implemented in
https://reviews.llvm.org/D16737 and enables support of dead code stripping
option on Mach-O platforms.

As part of enabling the feature, I also plan on reverting the following
patch to compiler-rt:

http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160704/369910.html

Differential Revision: https://reviews.llvm.org/D26772

llvm-svn: 287235
2016-11-17 16:55:40 +00:00
Chris Bieneman 05c279fc4b [CMake] NFC. Updating CMake dependency specifications
This patch updates a bunch of places where add_dependencies was being explicitly called to add dependencies on intrinsics_gen to instead use the DEPENDS named parameter. This cleanup is needed for a patch I'm working on to add a dependency debugging mode to the build system.

llvm-svn: 287206
2016-11-17 04:36:50 +00:00
Reid Kleckner 3a83e76811 [sancov] Name the global containing the main source file name
If the global name doesn't start with __sancov_gen, ASan will insert
unecessary red zones around it.

llvm-svn: 287117
2016-11-16 16:50:43 +00:00
Filipe Cabecinhas ec350b71fa [AddressSanitizer] Add support for (constant-)masked loads and stores.
This patch adds support for instrumenting masked loads and stores under
ASan, if they have a constant mask.

isInterestingMemoryAccess now supports returning a mask to be applied to
the loads, and instrumentMop will use it to generate additional checks.

Added tests for v4i32 v8i32, and v4p0i32 (~v4i64) for both loads and
stores (as well as a test to verify we don't add checks to non-constant
masks).

Differential Revision: https://reviews.llvm.org/D26230

llvm-svn: 287047
2016-11-15 22:37:30 +00:00
Kostya Serebryany 9d6dc7b164 [sanitizer-coverage] make sure asan does not instrument coverage guards (reported in https://github.com/google/oss-fuzz/issues/84)
llvm-svn: 287030
2016-11-15 21:12:50 +00:00
Craig Topper c7486af9c9 [AVX-512] Add AVX-512 vector shift intrinsics to memory santitizer.
Just needed to add the intrinsics to the exist switch. The code is generic enough to support the wider vectors with no changes.

llvm-svn: 286980
2016-11-15 16:27:33 +00:00
Kuba Brecka ddfdba3b01 [tsan] Add support for C++ exceptions into TSan (call __tsan_func_exit during unwinding), LLVM part
This adds support for TSan C++ exception handling, where we need to add extra calls to __tsan_func_exit when a function is exitted via exception mechanisms. Otherwise the shadow stack gets corrupted (leaked). This patch moves and enhances the existing implementation of EscapeEnumerator that finds all possible function exit points, and adds extra EH cleanup blocks where needed.

Differential Revision: https://reviews.llvm.org/D26177

llvm-svn: 286893
2016-11-14 21:41:13 +00:00
Anna Zaks 3c43737832 [tsan][llvm] Implement the function attribute to disable TSan checking at run time
This implements a function annotation that disables TSan checking for the
function at run time. The benefit over attribute((no_sanitize("thread")))
is that the accesses within the callees will also be suppressed.

The motivation for this attribute is a guarantee given by the objective C
language that the calls to the reference count decrement and object
deallocation will be synchronized. To model this properly, we would need
to intercept all ref count decrement calls (which are very common in ObjC
due to use of ARC) and also every single message send. Instead, we propose
to just ignore all accesses made from within dealloc at run time. The main
downside is that this still does not introduce any synchronization, which
means we might still report false positives if the code that relies on this
synchronization is not executed from within dealloc. However, we have not seen
this in practice so far and think these cases will be very rare.

Differential Revision: https://reviews.llvm.org/D25858

llvm-svn: 286663
2016-11-11 23:01:02 +00:00
Reid Kleckner ec80354873 [sancov] Don't instrument MSVC CRT stdio config helpers
They get called before initialization, which is a problem for winasan.

Test coming in compiler-rt.

llvm-svn: 286615
2016-11-11 19:18:45 +00:00
Kuba Brecka a49dcbb743 [asan] Speed up compilation of large C++ stringmaps (tons of allocas) with ASan
This addresses PR30746, <https://llvm.org/bugs/show_bug.cgi?id=30746>. The ASan pass iterates over entry-block instructions and checks each alloca whether it's in NonInstrumentedStaticAllocaVec, which is apparently slow. This patch gathers the instructions to move during visitAllocaInst.

Differential Revision: https://reviews.llvm.org/D26380

llvm-svn: 286296
2016-11-08 21:30:41 +00:00
Evgeniy Stepanov cd729d6236 Use -fsanitize-recover instead of -mllvm -msan-keep-going.
Summary: Use -fsanitize-recover instead of -mllvm -msan-keep-going.

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26352

llvm-svn: 286145
2016-11-07 21:00:10 +00:00
Kuba Brecka 44e875ad5b [tsan] Cast floating-point types correctly when instrumenting atomic accesses, LLVM part
Although rare, atomic accesses to floating-point types seem to be valid, i.e. `%a = load atomic float ...`. The TSan instrumentation pass however tries to emit inttoptr, which is incorrect, we should use a bitcast here. Anyway, IRBuilder already has a convenient helper function for this.

Differential Revision: https://reviews.llvm.org/D26266

llvm-svn: 286135
2016-11-07 19:09:56 +00:00
Kuba Brecka a28c9e8f09 [asan] Move instrumented null-terminated strings to a special section, LLVM part
On Darwin, simple C null-terminated constant strings normally end up in the __TEXT,__cstring section of the resulting Mach-O binary. When instrumented with ASan, these strings are transformed in a way that they cannot be in __cstring (the linker unifies the content of this section and strips extra NUL bytes, which would break instrumentation), and are put into a generic __const section. This breaks some of the tools that we have: Some tools need to scan all C null-terminated strings in Mach-O binaries, and scanning all the contents of __const has a large performance penalty. This patch instead introduces a special section, __asan_cstring which will now hold the instrumented null-terminated strings.

Differential Revision: https://reviews.llvm.org/D25026

llvm-svn: 285619
2016-10-31 18:51:58 +00:00
Evgeniy Stepanov ea6d49d3ee Utility functions for appending to llvm.used/llvm.compiler.used.
llvm-svn: 285143
2016-10-25 23:53:31 +00:00
Rong Xu 33308f92eb [PGO] Fix select instruction annotation
Summary:
Select instruction annotation in IR PGO uses the edge count to infer the
branch count. It's currently placed in setInstrumentedCounts() where
no all the BB counts have been computed. This leads to wrong branch weights.
Move the annotation after all BB counts are populated.

Reviewers: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25961

llvm-svn: 285128
2016-10-25 21:47:24 +00:00
Vitaly Buka 5910a92560 [asan] Simplify calculation of stack frame layout extraction calculation of stack description into separate function.
Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25754

llvm-svn: 284547
2016-10-18 23:29:52 +00:00
Vitaly Buka d88e52012b [asan] Append line number to variable name if line is available and in the same file as the function.
PR30498

Reviewers: eugenis

Differential Revision: https://reviews.llvm.org/D25715

llvm-svn: 284546
2016-10-18 23:29:41 +00:00
Benjamin Kramer ee042234ae [esan] Remove global variable.
It's not thread safe and completely unnecessary.

llvm-svn: 284520
2016-10-18 19:39:23 +00:00
Vitaly Buka 8e1906ea7e [asan] Make -asan-experimental-poisoning the only behavior
Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25735

llvm-svn: 284505
2016-10-18 18:04:59 +00:00
Kostya Serebryany 4d25ad93f3 [sanitizer-coverage] use private linkage for coverage guards, delete old commented-out code.
llvm-svn: 283924
2016-10-11 19:36:50 +00:00
Rong Xu 0e79f7d11d [PGO] Create weak alias for the renamed Comdat function
Add a weak alias to the renamed Comdat function in IR level instrumentation,
using it's original name. This ensures the same behavior w/ and w/o IR
instrumentation, even for non standard conforming code.

Differential Revision: http://reviews.llvm.org/D25339

llvm-svn: 283490
2016-10-06 20:38:13 +00:00
Sagar Thakur f9292220dc [EfficiencySanitizer] Adds shadow memory parameters for 40-bit virtual memory address.
Adding 40-bit shadow memory parameters because MIPS64 uses 40-bit virtual memory addresses.

Reviewed by rengolin.
Differential: https://reviews.llvm.org/D23801

llvm-svn: 283433
2016-10-06 09:52:06 +00:00
Anna Zaks 9a6a6eff0e [asan] Reapply: Switch to using dynamic shadow offset on iOS
The VM layout is not stable between iOS version releases, so switch to dynamic shadow offset.

This is the LLVM counterpart of https://reviews.llvm.org/D25218

Differential Revision: https://reviews.llvm.org/D25219

llvm-svn: 283376
2016-10-05 20:34:13 +00:00
Anna Zaks e732ce4dff Revert "[asan] LLVM: Switch to using dynamic shadow offset on iOS"
This reverts commit abe77a118615cd90b0d7f127e4797096afa2b394.

Revert as these changes broke a Chromium buildbot.

llvm-svn: 283348
2016-10-05 17:42:02 +00:00
Anna Zaks ef97d2c589 [asan] LLVM: Switch to using dynamic shadow offset on iOS
The VM layout is not stable between iOS version releases, so switch to dynamic shadow offset.

This is the LLVM counterpart of https://reviews.llvm.org/D25218

Differential Revision: https://reviews.llvm.org/D25219

llvm-svn: 283239
2016-10-04 19:02:29 +00:00
Mehdi Amini 117296c0a0 Use StringRef in Pass/PassManager APIs (NFC)
llvm-svn: 283004
2016-10-01 02:56:57 +00:00
Mehdi Amini 6610b01a27 [ASAN] Add the binder globals on Darwin to llvm.compiler.used to avoid LTO dead-stripping
The binder is in a specific section that "reverse" the edges in a
regular dead-stripping: the binder is live as long as a global it
references is live.

This is a big hammer that prevents LLVM from dead-stripping these,
while still allowing linker dead-stripping (with special knowledge
of the section).

Differential Revision: https://reviews.llvm.org/D24673

llvm-svn: 282988
2016-10-01 00:05:34 +00:00
Etienne Bergeron 0ca0568604 [asan] Support dynamic shadow address instrumentation
Summary:
This patch is adding the support for a shadow memory with
dynamically allocated address range.

The compiler-rt needs to export a symbol containing the shadow
memory range.

This is required to support ASAN on windows 64-bits.

Reviewers: kcc, rnk, vitalybuka

Subscribers: zaks.anna, kubabrecka, dberris, llvm-commits, chrisha

Differential Revision: https://reviews.llvm.org/D23354

llvm-svn: 282881
2016-09-30 17:46:32 +00:00
Kostya Serebryany a9b0dd0e51 [sanitizer-coverage/libFuzzer] make the guards for trace-pc 32-bit; create one array of guards per function, instead of one guard per BB. reorganize the code so that trace-pc-guard does not create unneeded globals
llvm-svn: 282735
2016-09-29 17:43:24 +00:00
Kostya Serebryany 45c144754b [sanitizer-coverage] fix a bug in trace-gep
llvm-svn: 282467
2016-09-27 01:55:08 +00:00
Kostya Serebryany 186d61801c [sanitizer-coverage] don't emit the CTOR function if nothing has been instrumented
llvm-svn: 282465
2016-09-27 01:08:33 +00:00
Etienne Bergeron 7f0e315327 [compiler-rt] fix typo in option description [NFC]
llvm-svn: 282163
2016-09-22 14:57:24 +00:00
Sagar Thakur e74eb4e7b9 [EfficiencySanitizer] Using '$' instead of '#' for struct counter name
For MIPS '#' is the start of comment line. Therefore we get assembler errors if # is used in the structure names.

Differential: D24334
Reviewed by: zhaoqin

llvm-svn: 282141
2016-09-22 08:33:06 +00:00
Nico Weber a489438849 revert 281908 because 281909 got reverted
llvm-svn: 282097
2016-09-21 18:25:43 +00:00
Xinliang David Li 9780fc1451 code cleanup -- commoning IR travsersals
llvm-svn: 282034
2016-09-20 22:39:47 +00:00
Xinliang David Li c7368287b7 [Profile] Do not annotate select insts not covered in profile.
Fixed PR/30466

llvm-svn: 282009
2016-09-20 20:20:01 +00:00
Xinliang David Li a754c47ac5 [Profile] code refactoring: make getStep a method in base class
llvm-svn: 282002
2016-09-20 19:07:22 +00:00
Adrian Prantl 12fa3b3911 ASAN: Don't drop debug info attachements for global variables.
This is a follow-up to r281284. Global Variables now can have
!dbg attachements, so ASAN should clone these when generating a
sanitized copy of a global variable.

<rdar://problem/24899262>

llvm-svn: 281994
2016-09-20 18:28:42 +00:00
Kostya Serebryany 06694d0a2f [sanitizer-coverage] add comdat to coverage guards if needed
llvm-svn: 281952
2016-09-20 00:16:54 +00:00
Etienne Bergeron 6ba5176862 [asan] Support dynamic shadow address instrumentation
Summary:
This patch is adding the support for a shadow memory with
dynamically allocated address range.

The compiler-rt needs to export a symbol containing the shadow
memory range.

This is required to support ASAN on windows 64-bits.

Reviewers: kcc, rnk, vitalybuka

Subscribers: kubabrecka, dberris, llvm-commits, chrisha

Differential Revision: https://reviews.llvm.org/D23354

llvm-svn: 281908
2016-09-19 15:58:38 +00:00
Simon Pilgrim f33a6b713b Fix covered-switch-default warning
llvm-svn: 281865
2016-09-18 21:08:35 +00:00
Xinliang David Li f0630d3d96 Fix built bot failure
llvm-svn: 281859
2016-09-18 18:52:08 +00:00
Xinliang David Li 4ca1733a06 [Profile] Implement select instruction instrumentation in IR PGO
Differential Revision: http://reviews.llvm.org/D23727

llvm-svn: 281858
2016-09-18 18:34:07 +00:00
Kostya Serebryany 8e781a888a [libFuzzer] use 'if guard' instead of 'if guard >= 0' with trace-pc; change the guard type to intptr_t; use separate array for 8-bit counters
llvm-svn: 281845
2016-09-18 04:52:23 +00:00
Kostya Serebryany 8ad4155745 [sanitizer-coverage] change trace-pc to use 8-byte guards
llvm-svn: 281809
2016-09-17 05:03:05 +00:00
Vitaly Buka 6c7a0bc3d9 Revert "[asan] Avoid lifetime analysis for allocas with can be in ambiguous state"
This approach is not good enough. Working on the new solution.

This reverts commit r280907.

llvm-svn: 281689
2016-09-16 01:38:46 +00:00
Vitaly Buka 4670ae5f61 Revert "[asan] Add flag to allow lifetime analysis of problematic allocas"
This approach is not good enough. Working on the new solution.

This reverts commit r281126.

llvm-svn: 281688
2016-09-16 01:38:43 +00:00
Kostya Serebryany 66a9c175bf [sanitizer-coverage] make trace-pc-guard and indirect-call work together
llvm-svn: 281665
2016-09-15 22:11:08 +00:00
Etienne Bergeron 78582b2ada [compiler-rt] Changing function prototype returning unused value
Summary: The return value of `maybeInsertAsanInitAtFunctionEntry` is ignored.

Reviewers: rnk

Subscribers: llvm-commits, chrisha, dberris

Differential Revision: https://reviews.llvm.org/D24568

llvm-svn: 281620
2016-09-15 15:45:05 +00:00
Etienne Bergeron 52e4743e24 Fix silly mistake introduced here : https://reviews.llvm.org/D24566
Asan bots are currently broken without this patch.

llvm-svn: 281618
2016-09-15 15:35:59 +00:00
Etienne Bergeron c0669ce984 address comments from: https://reviews.llvm.org/D24566
using startswith instead of find.

llvm-svn: 281617
2016-09-15 15:19:19 +00:00
Etienne Bergeron 752f8839a4 [compiler-rt] Avoid instrumenting sanitizer functions
Summary:
Function __asan_default_options is called by __asan_init before the
shadow memory got initialized. Instrumenting that function may lead
to flaky execution.

As the __asan_default_options is provided by users, we cannot expect
them to add the appropriate function atttributes to avoid
instrumentation.

Reviewers: kcc, rnk

Subscribers: dberris, chrisha, llvm-commits

Differential Revision: https://reviews.llvm.org/D24566

llvm-svn: 281503
2016-09-14 17:18:37 +00:00
Etienne Bergeron 9bd4281006 Fix typo in comment [NFC]
llvm-svn: 281492
2016-09-14 15:59:32 +00:00
Kuba Brecka a1ea64a044 [asan] Enable -asan-use-private-alias on Darwin/Mach-O, add test for ODR false positive with LTO (llvm part)
The '-asan-use-private-alias’ option (disabled by default) option is currently only enabled for Linux and ELF, but it also works on Darwin and Mach-O. This option also fixes a known problem with LTO on Darwin (https://github.com/google/sanitizers/issues/647). This patch enables the support for Darwin (but still keeps it off by default) and adds the LTO test case.

Differential Revision: https://reviews.llvm.org/D24292

llvm-svn: 281470
2016-09-14 14:06:33 +00:00
Kostya Serebryany da718e55cf [sanitizer-coverage] add yet another flavour of coverage instrumentation: trace-pc-guard. The intent is to eventually replace all of {bool coverage, 8bit-counters, trace-pc} with just this one. LLVM part
llvm-svn: 281431
2016-09-14 01:39:35 +00:00
Vitaly Buka 3ac3aa50f6 [asan] Add flag to allow lifetime analysis of problematic allocas
Summary:
Could be useful for comparison when we suspect that alloca was skipped
because of this.

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24437

llvm-svn: 281126
2016-09-10 01:06:11 +00:00
Vitaly Buka 58a81c6540 [asan] Avoid lifetime analysis for allocas with can be in ambiguous state
Summary:
C allows to jump over variables declaration so lifetime.start can be
avoid before variable usage. To avoid false-positives on such rare cases
we detect them and remove from lifetime analysis.

PR27453
PR28267

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24321

llvm-svn: 280907
2016-09-08 06:27:58 +00:00
Vitaly Buka c5e53b2a53 Revert "[asan] Avoid lifetime analysis for allocas with can be in ambiguous state"
Fails on Windows.

This reverts commit r280880.

llvm-svn: 280883
2016-09-07 23:37:15 +00:00
Vitaly Buka 2ca05b07d6 [asan] Avoid lifetime analysis for allocas with can be in ambiguous state
Summary:
C allows to jump over variables declaration so lifetime.start can be
avoid before variable usage. To avoid false-positives on such rare cases
we detect them and remove from lifetime analysis.

PR27453
PR28267

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24321

llvm-svn: 280880
2016-09-07 23:18:23 +00:00
Renato Golin c69e0818e0 Revert "[EfficiencySanitizer] Adds shadow memory parameters for 40-bit virtual memory address."
This reverts commit r280796, as it broke the AArch64 bots for no reason.

The tests were passing and we should try to keep them passing, so a proper
review should make that happen.

llvm-svn: 280802
2016-09-07 10:54:42 +00:00
Sagar Thakur 69c78d8db7 [EfficiencySanitizer] Adds shadow memory parameters for 40-bit virtual memory address.
Adding 40-bit shadow memory parameters because MIPS64 uses 40-bit virtual memory addresses.

Reviewed by bruening
Differential: D23801

llvm-svn: 280796
2016-09-07 09:45:37 +00:00
Nick Lewycky 8dd4dad08b Add cast to appease windows builder. Fixes build break introduced in r280306.
llvm-svn: 280311
2016-08-31 23:24:43 +00:00
Nick Lewycky 97e49ac59e Add -fprofile-dir= to clang.
-fprofile-dir=path allows the user to specify where .gcda files should be
emitted when the program is run. In particular, this is the first flag that
causes the .gcno and .o files to have different paths, LLVM is extended to
support this. -fprofile-dir= does not change the file name in the .gcno (and
thus where lcov looks for the source) but it does change the name in the .gcda
(and thus where the runtime library writes the .gcda file). It's different from
a GCOV_PREFIX because a user can observe that the GCOV_PREFIX_STRIP will strip
paths off of -fprofile-dir= but not off of a supplied GCOV_PREFIX.

To implement this we split -coverage-file into -coverage-data-file and
-coverage-notes-file to specify the two different names. The !llvm.gcov
metadata node grows from a 2-element form {string coverage-file, node dbg.cu}
to 3-elements, {string coverage-notes-file, string coverage-data-file, node
dbg.cu}. In the 3-element form, the file name is already "mangled" with
.gcno/.gcda suffixes, while the 2-element form left that to the middle end
pass.

llvm-svn: 280306
2016-08-31 23:04:32 +00:00
Kostya Serebryany 5ac427b8e4 [sanitizer-coverage] add two more modes of instrumentation: trace-div and trace-gep, mostly usaful for value-profile-based fuzzing; llvm part
llvm-svn: 280043
2016-08-30 01:12:10 +00:00
Vitaly Buka 3c4f6bf654 [asan] Enable new stack poisoning with store instruction by default
Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23968

llvm-svn: 279993
2016-08-29 19:28:34 +00:00
Vitaly Buka 793913c7eb Use store operation to poison allocas for lifetime analysis.
Summary:
Calling __asan_poison_stack_memory and __asan_unpoison_stack_memory for small
variables is too expensive.

Code is disabled by default and can be enabled by -asan-experimental-poisoning.

PR27453

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23947

llvm-svn: 279984
2016-08-29 18:17:21 +00:00
Vitaly Buka db331d8be7 [asan] Separate calculation of ShadowBytes from calculating ASanStackFrameLayout
Summary: No functional changes, just refactoring to make D23947 simpler.

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23954

llvm-svn: 279982
2016-08-29 17:41:29 +00:00
Vitaly Buka 0672a27bb5 [asan] Use 1 byte aligned stores to poison shadow memory
Summary: r279379 introduced crash on arm 32bit bot. I suspect this is alignment issue.

Reviewers: eugenis

Subscribers: llvm-commits, aemerson

Differential Revision: https://reviews.llvm.org/D23762

llvm-svn: 279413
2016-08-22 04:16:14 +00:00
Vitaly Buka 1f9e135023 [asan] Minimize code size by using __asan_set_shadow_* for large blocks
Summary:
We can insert function call instead of multiple store operation.
Current default is blocks larger than 64 bytes.
Changes are hidden behind -asan-experimental-poisoning flag.

PR27453

Differential Revision: https://reviews.llvm.org/D23711

llvm-svn: 279383
2016-08-20 20:23:50 +00:00
Vitaly Buka 3455b9b8bc [asan] Initialize __asan_set_shadow_* callbacks
Summary:
Callbacks are not being used yet.

PR27453

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23634

llvm-svn: 279380
2016-08-20 18:34:39 +00:00
Vitaly Buka 186280daa5 [asan] Optimize store size in FunctionStackPoisoner::poisonRedZones
Summary: Reduce store size to avoid leading and trailing zeros.

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23648

llvm-svn: 279379
2016-08-20 18:34:36 +00:00
Vitaly Buka 5b4f12176c [asan] Cleanup instrumentation of dynamic allocas
Summary:
Extract instrumenting dynamic allocas into separate method.
Rename asan-instrument-allocas -> asan-instrument-dynamic-allocas

Differential Revision: https://reviews.llvm.org/D23707

llvm-svn: 279376
2016-08-20 17:22:27 +00:00
Vitaly Buka f9fd63ad39 [asan] Add support of lifetime poisoning into ComputeASanStackFrameLayout
Summary:
We are going to combine poisoning of red zones and scope poisoning.

PR27453

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23623

llvm-svn: 279373
2016-08-20 16:48:24 +00:00
Vitaly Buka e149b392a8 Revert "[asan] Add support of lifetime poisoning into ComputeASanStackFrameLayout"
This reverts commit r279020.

Speculative revert in hope to fix asan test on arm.

llvm-svn: 279332
2016-08-19 22:12:58 +00:00
Vitaly Buka 170dede75d Revert "[asan] Optimize store size in FunctionStackPoisoner::poisonRedZones"
This reverts commit r279178.

Speculative revert in hope to fix asan crash on arm.

llvm-svn: 279277
2016-08-19 17:15:38 +00:00
Vitaly Buka c8f4d69c82 Revert "[asan] Fix size of shadow incorrectly calculated in r279178"
This reverts commit r279222.

Speculative revert in hope to fix asan crash on arm.

llvm-svn: 279276
2016-08-19 17:15:33 +00:00
Vitaly Buka b81960a6c8 [asan] Fix size of shadow incorrectly calculated in r279178
Summary: r279178 generates 8 times more stores than necessary.

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23708

llvm-svn: 279222
2016-08-19 08:33:53 +00:00
Xinliang David Li 63248ab888 [Profile] Fix edge count read bug
Use uint64_t to avoid value truncation before scaling.

llvm-svn: 279213
2016-08-19 06:31:45 +00:00
Xinliang David Li 2c9336823c [Profile] Simple code refactoring for reuse /NFC
llvm-svn: 279209
2016-08-19 05:31:33 +00:00
Vitaly Buka aa654292bd [asan] Optimize store size in FunctionStackPoisoner::poisonRedZones
Summary: Reduce store size to avoid leading and trailing zeros.

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23648

llvm-svn: 279178
2016-08-18 23:51:15 +00:00
Kostya Serebryany 524c3f32e7 [sanitizer-coverage/libFuzzer] instrument comparisons with __sanitizer_cov_trace_cmp[1248] instead of __sanitizer_cov_trace_cmp, don't pass the comparison type to save a bit performance. Use these new callbacks in libFuzzer
llvm-svn: 279027
2016-08-18 01:25:28 +00:00
Vitaly Buka d5ec14989d [asan] Add support of lifetime poisoning into ComputeASanStackFrameLayout
Summary:
We are going to combine poisoning of red zones and scope poisoning.

PR27453

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23623

llvm-svn: 279020
2016-08-18 00:56:58 +00:00
Justin Bogner b03fd12cef Replace "fallthrough" comments with LLVM_FALLTHROUGH
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.

llvm-svn: 278902
2016-08-17 05:10:15 +00:00
Vitaly Buka 1ce73ef11c [Asan] Unpoison red zones even if use-after-scope was disabled with runtime flag
Summary: PR27453

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23481

llvm-svn: 278818
2016-08-16 16:24:10 +00:00
Sagar Thakur e311740bde [MemorySanitizer] [MIPS] Changed memory mapping to support pie executable.
Reviewed by eugenis
Differential: D22994

llvm-svn: 278795
2016-08-16 12:55:38 +00:00
Eugene Zelenko cdc7161281 Fix some Clang-tidy modernize and Include What You Use warnings.
Differential revision: https://reviews.llvm.org/D23291

llvm-svn: 278364
2016-08-11 17:20:18 +00:00
Xinliang David Li 76a0108be4 [Profile] improve warning control option
Change --no-pgo-warn-missing to -pgo-warn-missing-function
and negate the default. /NFC

Add more test to make sure the warning is off by default

llvm-svn: 278314
2016-08-11 05:09:30 +00:00
Xinliang David Li 9035cfceef [Profile] turn off verbose warnings by default
no prof data for func warning is turned off by default
due to its high verbosity and minimal usefulness.

Differential Revision: http://reviews.llvm.org/D23295

llvm-svn: 278127
2016-08-09 15:35:28 +00:00
Sean Silva fd03ac6a0c Consistently use ModuleAnalysisManager
Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching every transformation and analysis to be factored out
cleanly.

Thanks to David for the suggestion.

llvm-svn: 278078
2016-08-09 00:28:38 +00:00
Xinliang David Li d119761bbe [Profile] IR profiling minor cleanup /nfc
Differential Revision: http://reviews.llvm.org/D22995

llvm-svn: 277379
2016-08-01 20:25:06 +00:00
Vitaly Buka 21a9e573ed [asan] Add const into few methods
Summary: No functional changes

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22899

llvm-svn: 277069
2016-07-28 22:50:50 +00:00
Rong Xu 705f7775bb [PGO] Fix profile mismatch in COMDAT function with pre-inliner
Pre-instrumentation inline (pre-inliner) greatly improves the IR
instrumentation code performance, among other benefits. One issue of the
pre-inliner is it can introduce CFG-mismatch for COMDAT functions. This
is due to the fact that the same COMDAT function may have different early
inline decisions across different modules -- that means different copies
of COMDAT functions will have different CFG checksum.

In this patch, we propose a partially renaming the COMDAT group and its
member function/variable so we have different profile counter for each
version. We will post-fix the COMDAT function and the group name with its
FunctionHash.

Differential Revision: http://reviews.llvm.org/D22600

llvm-svn: 276673
2016-07-25 18:45:37 +00:00
Vitaly Buka e3a032a740 Unpoison stack before resume instruction
Summary:
Clang inserts cleanup code before resume similar way as before return instruction.
This makes asan poison local variables causing false use-after-scope reports.

__asan_handle_no_return does not help here as it was executed before
llvm.lifetime.end inserted into resume block.

To avoid false report we need to unpoison stack for resume same way as for return.

PR27453

Reviewers: kcc, eugenis

Differential Revision: https://reviews.llvm.org/D22661

llvm-svn: 276480
2016-07-22 22:04:38 +00:00
Xinliang David Li d382e9d82b Sync up InstrProfData.inc with compiler-rt with fixes to references
llvm-svn: 276388
2016-07-22 04:46:56 +00:00
Vitaly Buka 53054a7024 Fix detection of stack-use-after scope for char arrays.
Summary:
Clang inserts GetElementPtrInst so findAllocaForValue was not
able to find allocas.

PR27453

Reviewers: kcc, eugenis

Differential Revision: https://reviews.llvm.org/D22657

llvm-svn: 276374
2016-07-22 00:56:17 +00:00
Xinliang David Li 6f8c504f10 [Profile] deprecate __llvm_profile_override_default_filename
This eliminates unncessary calls and init functions.

Differential Revision: http://reviews.llvm.org/D22613

llvm-svn: 276354
2016-07-21 23:19:10 +00:00
Rong Xu 97b68c5ebe [PGO] Make needsComdatForCounter() available (NFC)
Move needsComdatForCounter() to lib/ProfileData/InstrProf.cpp from
lib/Transforms/Instrumentation/InstrProfiling.cpp to make is available for
other files.

Differential Revision: https://reviews.llvm.org/D22643

llvm-svn: 276330
2016-07-21 20:50:02 +00:00
Vedant Kumar cd32eba67b Avoid a string copy, NFC
llvm-svn: 276310
2016-07-21 17:50:07 +00:00
Benjamin Kramer eab3d36753 Rename StringMap::emplace_second to try_emplace.
Coincidentally this function maps to the C++17 try_emplace. Rename it
for consistentcy with C++17 std::map. NFC.

llvm-svn: 276276
2016-07-21 13:37:48 +00:00