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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
-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
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
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
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
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
Summary:
Callbacks are not being used yet.
PR27453
Reviewers: kcc, eugenis
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D23634
llvm-svn: 279380
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
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
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
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
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
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
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
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
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
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
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
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
r274801 did not go far enough to allow gcov+tsan to cooperate. With this
commit it's possible to run the following code without false positives:
std::thread T1(fib), T2(fib);
T1.join(); T2.join();
llvm-svn: 276015
Summary:
Refactored the profitability analysis out of the IC promotion pass and
into lib/Analysis so that it can be accessed by the summary index
builder in a follow-on patch to enable IC promotion in ThinLTO (D21932).
Reviewers: davidxl, xur
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D22182
llvm-svn: 275705
Summary:
Refactored the profitability analysis out of the IC promotion pass and
into lib/Analysis so that it can be accessed by the summary index
builder in a follow-on patch to enable IC promotion in ThinLTO (D21932).
Reviewers: davidxl, xur
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D22182
llvm-svn: 275216
GCOVProfiler::emitProfileArcs() can create many variables with names
starting with "__llvm_gcov_ctr", so llvm appends a numeric suffix to
most of them. Teach tsan about this.
llvm-svn: 274801
Summary:
Adds option -esan-aux-field-info to control generating binary with
auxiliary struct field information.
Extracts code for creating auxiliary information from
createCacheFragInfoGV into createCacheFragAuxGV.
Adds test struct_field_small.ll for -esan-aux-field-info test.
Reviewers: aizatsky
Subscribers: llvm-commits, bruening, eugenis, kcc, zhaoqin, vitalybuka
Differential Revision: http://reviews.llvm.org/D22019
llvm-svn: 274726
Summary:
Fixes an incorrect assert that fails on 128-bit-sized loads or stores.
Augments the wset tests to include this case.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits
Differential Revision: http://reviews.llvm.org/D22062
llvm-svn: 274666
Fix incorrect calculation of the type size for __msan_maybe_warning_N
call that resulted in an invalid (narrowing) zext instruction and
"Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed."
Only happens in very large functions (with more than 3500 MSan
checks) operating on integer types that are not power-of-two.
llvm-svn: 274395
See the bug report at https://github.com/google/sanitizers/issues/691. When a dynamic alloca has a constant size, ASan instrumentation will treat it as a regular dynamic alloca (insert calls to poison and unpoison), but the backend will turn it into a regular stack variable. The poisoning/unpoisoning is then broken. This patch will treat such allocas as static.
Differential Revision: http://reviews.llvm.org/D21509
llvm-svn: 273888
It's only useful to asan-itize profiling globals while debugging llvm's
profiling instrumentation passes. Enabling asan along with instrprof or
gcov instrumentation shouldn't incur extra overhead.
This patch is in the same spirit as r264805 and r273202, which disabled
tsan instrumentation of instrprof/gcov globals.
Differential Revision: http://reviews.llvm.org/D21541
llvm-svn: 273444
Do not instrument pointers with address space attributes since we cannot track
them anyway. Instrumenting them results in false positives in ASan and a
compiler crash in TSan. (The compiler should not crash in any case, but that's
a different problem.)
llvm-svn: 273339
The large offset is being tested on Windows 10 (which has larger usable
virtual address space than Windows 8 or earlier)
Patch by: Wei Wang
Differential Revision: http://reviews.llvm.org/D21523
llvm-svn: 273269
There is a known intended race here. This is a follow-up to r264805,
which disabled tsan instrumentation for updates to instrprof counters.
For more background on this please see the discussion in D18164.
llvm-svn: 273202
CodeGen has hooks that allow targets to emit specialized code instead
of calls to memcmp, memchr, strcpy, stpcpy, strcmp, strlen, strnlen.
When ASan/MSan/TSan/ESan is in use, this sidesteps its interceptors, resulting
in uninstrumented memory accesses. To avoid that, make these sanitizers
mark the calls as nobuiltin.
Differential Revision: http://reviews.llvm.org/D19781
llvm-svn: 273083
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.
This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
the normal rule that the global must have a unique address can be broken without
being observable by the program by performing comparisons against the global's
address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
its own copy of the global if it requires one, and the copy in each linkage unit
must be the same)
- It is a constant or a function (which means that the program cannot observe that
the unique-address rule has been broken by writing to the global)
Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.
See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.htmlhttp://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.
Part of the fix for PR27553.
Differential Revision: http://reviews.llvm.org/D20348
llvm-svn: 272709
Summary:
Iterates all (except the first and the last) operands within each GEP
instruction for instrumentation.
Adds test struct_field_gep.ll.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, bruening, llvm-commits
Differential Revision: http://reviews.llvm.org/D21242
llvm-svn: 272442
Summary:
Adds ClInstrumentFastpath option to control fastpath instrumentation.
Avoids the load/store instrumentation for the cache fragmentation tool.
Renames cache_frag_basic.ll to working_set_slow.ll for slowpath
instrumentation test.
Adds the __esan_init check in struct_field_count_basic.ll.
Reviewers: aizatsky
Subscribers: llvm-commits, bruening, eugenis, kcc, zhaoqin, vitalybuka
Differential Revision: http://reviews.llvm.org/D21079
llvm-svn: 272355
Summary:
We failed to unpoison uninteresting allocas on return as unpoisoning is part of
main instrumentation which skips such allocas.
Added check -asan-instrument-allocas for dynamic allocas. If instrumentation of
dynamic allocas is disabled it will not will not be unpoisoned.
PR27453
Reviewers: kcc, eugenis
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D21207
llvm-svn: 272341
Summary:
We still want to unpoison full stack even in use-after-return as it can be disabled at runtime.
PR27453
Reviewers: eugenis, kcc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D21202
llvm-svn: 272334
As suggested by clang-tidy's performance-unnecessary-copy-initialization.
This can easily hit lifetime issues, so I audited every change and ran the
tests under asan, which came back clean.
llvm-svn: 272126
Summary:
Adds an option -esan-assume-intra-cache-line which causes esan to assume
that a single memory access touches just one cache line, even if it is not
aligned, for better performance at a potential accuracy cost. Experiments
show that the performance difference can be 2x or more, and accuracy loss
is typically negligible, so we turn this on by default. This currently
applies just to the working set tool.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits
Differential Revision: http://reviews.llvm.org/D20978
llvm-svn: 271743
Summary:
Adds a global variable to specify the tool, to support handling early
interceptors that invoke instrumented code and require shadow memory to be
initialized prior to __esan_init() being invoked.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits
Differential Revision: http://reviews.llvm.org/D20973
llvm-svn: 271715
Summary:
Instrument GEP instruction for counting the number of struct field
address calculation to approximate the number of struct field accesses.
Adds test struct_field_count_basic.ll to test the struct field
instrumentation.
Reviewers: bruening, aizatsky
Subscribers: junbuml, zhaoqin, llvm-commits, eugenis, vitalybuka, kcc, bruening
Differential Revision: http://reviews.llvm.org/D20892
llvm-svn: 271619
Inline virtual functions has linkeonceodr linkage (emitted in comdat on
supporting targets). If the vtable for the class is not emitted in the
defining module, function won't be address taken thus its address is not
recorded. At the mercy of the linker, if the per-func prf_data from this
module (in comdat) is picked at link time, we will lose mapping from
function address to its hash val. This leads to missing icall promotion.
The second test case (currently disabled) in compiler_rt (r271528):
instrprof-icall-prom.test demostrates the bug. The first profile-use
subtest is fine due to linker order difference.
With this change, no missing icall targets is found in instrumented clang's
raw profile.
llvm-svn: 271532
Summary:
Creates a global variable containing preliminary information
for the cache-fragmentation tool runtime.
Passes a pointer to the variable (null if no variable is created) to the
compilation unit init and exit routines in the runtime.
Reviewers: aizatsky, bruening
Subscribers: filcab, kubabrecka, bruening, kcc, vitalybuka, eugenis, llvm-commits, zhaoqin
Differential Revision: http://reviews.llvm.org/D20541
llvm-svn: 271298
It was triggering an msan bot.
Revert "[IRPGO] Set the function entry count metadata."
This reverts commit r271090.
Revert "[IRPGO] Centralize the function attribute inliner hint logic. NFC."
This reverts commit r271089.
llvm-svn: 271091
Followup to D20528 clang patch, this removes the (V)CVTDQ2PD(Y) and (V)CVTPS2PD(Y) llvm intrinsics and auto-upgrades to sitofp/fpext instead.
Differential Revision: http://reviews.llvm.org/D20568
llvm-svn: 270678
Summary:
Adds fastpath instrumentation for esan's working set tool. The
instrumentation for an intra-cache-line load or store consists of an
inlined write to shadow memory bits for the corresponding cache line.
Adds a basic test for this instrumentation.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits
Differential Revision: http://reviews.llvm.org/D20483
llvm-svn: 270640
Summary:
Adds createEsanInitToolGV for creating a tool-specific variable passed
to the runtime library.
Adds dtor "esan.module_dtor" and inserts calls from the dtor to
"__esan_exit" in the runtime library.
Updates the EfficiencySanitizer test.
Patch by Qin Zhao.
Reviewers: aizatsky
Subscribers: bruening, kcc, vitalybuka, eugenis, llvm-commits
Differential Revision: http://reviews.llvm.org/D20488
llvm-svn: 270627
Summary:
Uses ModulePass instead of FunctionPass for EfficiencySanitizerPass to
better support global variable creation for a forthcoming struct field
counter tool.
Patch by Qin Zhao.
Reviewers: aizatsky
Subscribers: llvm-commits, eugenis, vitalybuka, bruening, kcc
Differential Revision: http://reviews.llvm.org/D20458
llvm-svn: 270263
Transition InstrProf and Coverage over to the stricter Error/Expected
interface.
Changes since the initial commit:
- Fix error message printing in llvm-profdata.
- Check errors in loadTestingFormat() + annotateAllFunctions().
- Defer error handling in InstrProfIterator to InstrProfReader.
- Remove the base ProfError class to work around an MSVC ICE.
Differential Revision: http://reviews.llvm.org/D19901
llvm-svn: 270020
Transition InstrProf and Coverage over to the stricter Error/Expected
interface.
Changes since the initial commit:
- Address undefined-var-template warning.
- Fix error message printing in llvm-profdata.
- Check errors in loadTestingFormat() + annotateAllFunctions().
- Defer error handling in InstrProfIterator to InstrProfReader.
Differential Revision: http://reviews.llvm.org/D19901
llvm-svn: 269694
Transition InstrProf and Coverage over to the stricter Error/Expected
interface.
Changes since the initial commit:
- Fix error message printing in llvm-profdata.
- Check errors in loadTestingFormat() + annotateAllFunctions().
- Defer error handling in InstrProfIterator to InstrProfReader.
Differential Revision: http://reviews.llvm.org/D19901
llvm-svn: 269491
Transition InstrProf and Coverage over to the stricter Error/Expected
interface.
Differential Revision: http://reviews.llvm.org/D19901
llvm-svn: 269462
Currently there is no reasonable way to control the warnings in the 'use' phase
of the IRPGO pass. This is problematic because the output can be somewhat
spammy. This patch adds some flags which allow us to optionally disable these
warnings. The current upstream behavior will remain the default.
Patch by Jake VanAdrighem (jvanadrighem@gmail.com)
Differential Revision: http://reviews.llvm.org/D20195
llvm-svn: 269437
This reverts commits r268969, r268979 and r268984. They had target specific test
in generic directories without the correct specifiers and made it hard for us to
come up with a good solution by rapidly committing untested changes.
This test needs to be in a target specific directory or have the correct REQUIRED
identifier.
llvm-svn: 269027
IR instrumentation generates a COMDAT symbol __llvm_profile_raw_version to
overwrite the same symbol in profile run-time to distinguish IR profiles from
Clang generated profiles. In MACHO, LinkOnceODR linkage is used due to the
lack of COMDAT support.
But LinkOnceODR linkage might have .weak_def_can_be_hidden assembly directive,
while the weak variable in run-time has a .weak_definition directive. Linker
will not merge these two symbols even they have the same name. The end result
is IR profiles are not properly flagged in MACHO.
This patch changes the linkage for __llvm_profile_raw_version in each module to
LinkOnceAny so that it has same .weak_definition directive as in the run-time.
Differential Revision: http://reviews.llvm.org/D20078
llvm-svn: 268969
This fixes http://llvm.org/PR27646 on AArch64.
There are three issues here:
- The GR save area is 7 words in size, instead of 8. This is not enough
if none of the fixed arguments is passed in GRs (they're all floats or
aggregates).
- The first argument is ignored (which counteracts the above if it's passed
in GR).
- Like x86_64, fixed arguments landing in the overflow area are wrongly
counted towards the overflow offset.
Differential Revision: http://reviews.llvm.org/D20023
llvm-svn: 268967
Allowing overriding the default ASAN shadow mapping offset with the
-asan-shadow-offset option, and allow zero to be specified for both offset and
scale.
Patch by Aaron Carroll <aaronc@apple.com>.
llvm-svn: 268724
Allowing overriding the default ASAN shadow mapping offset with the
-asan-shadow-offset option, and allow zero to be specified for both offset and
scale.
llvm-svn: 268586
Be more specific in describing compression failures. Also, check for
this kind of error in emitNameData().
This is part of a series of patches to transition ProfileData over to
the stricter Error/Expected interface.
llvm-svn: 268400
SystemZ on Linux currently has 53-bit address space. In theory, the hardware
could support a full 64-bit address space, but that's not supported due to
kernel limitations (it'd require 5-level page tables), and there are no plans
for that. The default process layout stays within first 4TB of address space
(to avoid creating 4-level page tables), so any offset >= (1 << 42) is fine.
Let's use 1 << 52 here, ie. exactly half the address space.
I've originally used 7 << 50 (uses top 1/8th of the address space), but ASan
runtime assumes there's some space after the shadow area. While this is
fixable, it's simpler to avoid the issue entirely.
Also, I've originally wanted to have the shadow aligned to 1/8th the address
space, so that we can use OR like X86 to assemble the offset. I no longer
think it's a good idea, since using ADD enables us to load the constant just
once and use it with register + register indexed addressing.
Differential Revision: http://reviews.llvm.org/D19650
llvm-svn: 268161
This patch implements the transformation that promotes indirect calls to
conditional direct calls when the indirect-call value profile meta-data is
available.
Differential Revision: http://reviews.llvm.org/D17864
llvm-svn: 267815
The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).
Differential Revision: http://reviews.llvm.org/D19172
llvm-svn: 267231
This patch changes the interface for createPGOFuncNameMetadata() where we add
another PGOFuncName argument.
Differential Revision: http://reviews.llvm.org/D19433
llvm-svn: 267216
Summary:
Adds an instrumentation pass for the new EfficiencySanitizer ("esan")
performance tuning family of tools. Multiple tools will be supported
within the same framework. Preliminary support for a cache fragmentation
tool is included here.
The shared instrumentation includes:
+ Turn mem{set,cpy,move} instrinsics into library calls.
+ Slowpath instrumentation of loads and stores via callouts to
the runtime library.
+ Fastpath instrumentation will be per-tool.
+ Which memory accesses to ignore will be per-tool.
Reviewers: eugenis, vitalybuka, aizatsky, filcab
Subscribers: filcab, vkalintiris, pcc, silvas, llvm-commits, zhaoqin, kcc
Differential Revision: http://reviews.llvm.org/D19167
llvm-svn: 267058
This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations.
The bisection is enabled using a new command line option (-opt-bisect-limit). Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit. A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used.
The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check. Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute. A new function call has been added for module and SCC passes that behaves in a similar way.
Differential Revision: http://reviews.llvm.org/D19172
llvm-svn: 267022
Summary:
This is done for consistency with asan-use-after-return.
I see no other users than tests.
Reviewers: aizatsky, kcc
Differential Revision: http://reviews.llvm.org/D19306
llvm-svn: 266906
Removed some unused headers, replaced some headers with forward class declarations.
Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'
Patch by Eugene Kosov <claprix@yandex.ru>
Differential Revision: http://reviews.llvm.org/D19219
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.
Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.
Motivation
----------
Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.
We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.
Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.
http://reviews.llvm.org/D19034
<rdar://problem/25256815>
llvm-svn: 266446
Summary:
In the context of http://wg21.link/lwg2445 C++ uses the concept of
'stronger' ordering but doesn't define it properly. This should be fixed
in C++17 barring a small question that's still open.
The code currently plays fast and loose with the AtomicOrdering
enum. Using an enum class is one step towards tightening things. I later
also want to tighten related enums, such as clang's
AtomicOrderingKind (which should be shared with LLVM as a 'C++ ABI'
enum).
This change touches a few lines of code which can be improved later, I'd
like to keep it as NFC for now as it's already quite complex. I have
related changes for clang.
As a follow-up I'll add:
bool operator<(AtomicOrdering, AtomicOrdering) = delete;
bool operator>(AtomicOrdering, AtomicOrdering) = delete;
bool operator<=(AtomicOrdering, AtomicOrdering) = delete;
bool operator>=(AtomicOrdering, AtomicOrdering) = delete;
This is separate so that clang and LLVM changes don't need to be in sync.
Reviewers: jyknight, reames
Subscribers: jyknight, llvm-commits
Differential Revision: http://reviews.llvm.org/D18775
llvm-svn: 265602
Direct callees' that are cast to other function prototypes,
show up in the Call/Invoke instructions as ConstantExpr's.
Currently llvm::CallSite's getCalledFunction() fails
to return the callees in such expressions as direct calls.
Value profiling should avoid instrumenting such cases. Mostly NFC.
llvm-svn: 265330
Use a helper function to find all the direct-calls-sites in a function.
Also split the code into a separated file as this will be use by
indirect-call-promotion transformation.
Differential Revision: http://reviews.llvm.org/D18704
llvm-svn: 265199
Refactor the code that gets and creates PGOFuncName meta data so that it can be
used in clang's value profile annotation.
Differential Revision: http://reviews.llvm.org/D18623
llvm-svn: 265149
Evgeniy Stepanov