Commit Graph

1950 Commits

Author SHA1 Message Date
James Y Knight fadf25068e Revert "[opaque pointer types] Add a FunctionCallee wrapper type, and use it."
This reverts commit f47d6b38c7 (r352791).

Seems to run into compilation failures with GCC (but not clang, where
I tested it). Reverting while I investigate.

llvm-svn: 352800
2019-01-31 21:51:58 +00:00
James Y Knight f47d6b38c7 [opaque pointer types] Add a FunctionCallee wrapper type, and use it.
The FunctionCallee type is effectively a {FunctionType*,Value*} pair,
and is a useful convenience to enable code to continue passing the
result of getOrInsertFunction() through to EmitCall, even once pointer
types lose their pointee-type.

Then:
- update the CallInst/InvokeInst instruction creation functions to
  take a Callee,
- modify getOrInsertFunction to return FunctionCallee, and
- update all callers appropriately.

One area of particular note is the change to the sanitizer
code. Previously, they had been casting the result of
`getOrInsertFunction` to a `Function*` via
`checkSanitizerInterfaceFunction`, and storing that. That would report
an error if someone had already inserted a function declaraction with
a mismatching signature.

However, in general, LLVM allows for such mismatches, as
`getOrInsertFunction` will automatically insert a bitcast if
needed. As part of this cleanup, cause the sanitizer code to do the
same. (It will call its functions using the expected signature,
however they may have been declared.)

Finally, in a small number of locations, callers of
`getOrInsertFunction` actually were expecting/requiring that a brand
new function was being created. In such cases, I've switched them to
Function::Create instead.

Differential Revision: https://reviews.llvm.org/D57315

llvm-svn: 352791
2019-01-31 20:35:56 +00:00
Erik Pilkington 600e9deacf Add a 'dynamic' parameter to the objectsize intrinsic
This is meant to be used with clang's __builtin_dynamic_object_size.
When 'true' is passed to this parameter, the intrinsic has the
potential to be folded into instructions that will be evaluated
at run time. When 'false', the objectsize intrinsic behaviour is
unchanged.

rdar://32212419

Differential revision: https://reviews.llvm.org/D56761

llvm-svn: 352664
2019-01-30 20:34:35 +00:00
Peter Collingbourne 1a8acfb768 hwasan: If we split the entry block, move static allocas back into the entry block.
Otherwise they are treated as dynamic allocas, which ends up increasing
code size significantly. This reduces size of Chromium base_unittests
by 2MB (6.7%).

Differential Revision: https://reviews.llvm.org/D57205

llvm-svn: 352152
2019-01-25 02:08:46 +00:00
Julian Lettner b62e9dc46b Revert "[Sanitizers] UBSan unreachable incompatible with ASan in the presence of `noreturn` calls"
This reverts commit cea84ab93a.

llvm-svn: 352069
2019-01-24 18:04:21 +00:00
Julian Lettner cea84ab93a [Sanitizers] UBSan unreachable incompatible with ASan in the presence of `noreturn` calls
Summary:
UBSan wants to detect when unreachable code is actually reached, so it
adds instrumentation before every `unreachable` instruction. However,
the optimizer will remove code after calls to functions marked with
`noreturn`. To avoid this UBSan removes `noreturn` from both the call
instruction as well as from the function itself. Unfortunately, ASan
relies on this annotation to unpoison the stack by inserting calls to
`_asan_handle_no_return` before `noreturn` functions. This is important
for functions that do not return but access the the stack memory, e.g.,
unwinder functions *like* `longjmp` (`longjmp` itself is actually
"double-proofed" via its interceptor). The result is that when ASan and
UBSan are combined, the `noreturn` attributes are missing and ASan
cannot unpoison the stack, so it has false positives when stack
unwinding is used.

Changes:
  # UBSan now adds the `expect_noreturn` attribute whenever it removes
    the `noreturn` attribute from a function
  # ASan additionally checks for the presence of this attribute

Generated code:
```
call void @__asan_handle_no_return    // Additionally inserted to avoid false positives
call void @longjmp
call void @__asan_handle_no_return
call void @__ubsan_handle_builtin_unreachable
unreachable
```

The second call to `__asan_handle_no_return` is redundant. This will be
cleaned up in a follow-up patch.

rdar://problem/40723397

Reviewers: delcypher, eugenis

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D56624

llvm-svn: 352003
2019-01-24 01:06:19 +00:00
Peter Collingbourne 020ce3f026 hwasan: Read shadow address from ifunc if we don't need a frame record.
This saves a cbz+cold call in the interceptor ABI, as well as a realign
in both ABIs, trading off a dcache entry against some branch predictor
entries and some code size.

Unfortunately the functionality is hidden behind a flag because ifunc is
known to be broken on static binaries on Android.

Differential Revision: https://reviews.llvm.org/D57084

llvm-svn: 351989
2019-01-23 22:39:11 +00:00
Peter Collingbourne 73078ecd38 hwasan: Move memory access checks into small outlined functions on aarch64.
Each hwasan check requires emitting a small piece of code like this:
https://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html#memory-accesses

The problem with this is that these code blocks typically bloat code
size significantly.

An obvious solution is to outline these blocks of code. In fact, this
has already been implemented under the -hwasan-instrument-with-calls
flag. However, as currently implemented this has a number of problems:
- The functions use the same calling convention as regular C functions.
  This means that the backend must spill all temporary registers as
  required by the platform's C calling convention, even though the
  check only needs two registers on the hot path.
- The functions take the address to be checked in a fixed register,
  which increases register pressure.
Both of these factors can diminish the code size effect and increase
the performance hit of -hwasan-instrument-with-calls.

The solution that this patch implements is to involve the aarch64
backend in outlining the checks. An intrinsic and pseudo-instruction
are created to represent a hwasan check. The pseudo-instruction
is register allocated like any other instruction, and we allow the
register allocator to select almost any register for the address to
check. A particular combination of (register selection, type of check)
triggers the creation in the backend of a function to handle the check
for specifically that pair. The resulting functions are deduplicated by
the linker. The pseudo-instruction (really the function) is specified
to preserve all registers except for the registers that the AAPCS
specifies may be clobbered by a call.

To measure the code size and performance effect of this change, I
took a number of measurements using Chromium for Android on aarch64,
comparing a browser with inlined checks (the baseline) against a
browser with outlined checks.

Code size: Size of .text decreases from 243897420 to 171619972 bytes,
or a 30% decrease.

Performance: Using Chromium's blink_perf.layout microbenchmarks I
measured a median performance regression of 6.24%.

The fact that a perf/size tradeoff is evident here suggests that
we might want to make the new behaviour conditional on -Os/-Oz.
But for now I've enabled it unconditionally, my reasoning being that
hwasan users typically expect a relatively large perf hit, and ~6%
isn't really adding much. We may want to revisit this decision in
the future, though.

I also tried experimenting with varying the number of registers
selectable by the hwasan check pseudo-instruction (which would result
in fewer variants being created), on the hypothesis that creating
fewer variants of the function would expose another perf/size tradeoff
by reducing icache pressure from the check functions at the cost of
register pressure. Although I did observe a code size increase with
fewer registers, I did not observe a strong correlation between the
number of registers and the performance of the resulting browser on the
microbenchmarks, so I conclude that we might as well use ~all registers
to get the maximum code size improvement. My results are below:

Regs | .text size | Perf hit
-----+------------+---------
~all | 171619972  | 6.24%
  16 | 171765192  | 7.03%
   8 | 172917788  | 5.82%
   4 | 177054016  | 6.89%

Differential Revision: https://reviews.llvm.org/D56954

llvm-svn: 351920
2019-01-23 02:20:10 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

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

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

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Philip Pfaffe 81101de585 [MSan] Apply the ctor creation scheme of TSan
Summary: To avoid adding an extern function to the global ctors list, apply the changes of D56538 also to MSan.

Reviewers: chandlerc, vitalybuka, fedor.sergeev, leonardchan

Subscribers: hiraditya, bollu, llvm-commits

Differential Revision: https://reviews.llvm.org/D56734

llvm-svn: 351322
2019-01-16 11:14:07 +00:00
Philip Pfaffe 685c76d7a3 [NewPM][TSan] Reiterate the TSan port
Summary:
Second iteration of D56433 which got reverted in rL350719. The problem
in the previous version was that we dropped the thunk calling the tsan init
function. The new version keeps the thunk which should appease dyld, but is not
actually OK wrt. the current semantics of function passes. Hence, add a
helper to insert the functions only on the first time. The helper
allows hooking into the insertion to be able to append them to the
global ctors list.

Reviewers: chandlerc, vitalybuka, fedor.sergeev, leonardchan

Subscribers: hiraditya, bollu, llvm-commits

Differential Revision: https://reviews.llvm.org/D56538

llvm-svn: 351314
2019-01-16 09:28:01 +00:00
Matt Morehouse 19ff35c481 [SanitizerCoverage] Don't create comdat for interposable functions.
Summary:
Comdat groups override weak symbol behavior, allowing the linker to keep
the comdats for weak symbols in favor of comdats for strong symbols.

Fixes the issue described in:
https://bugs.chromium.org/p/chromium/issues/detail?id=918662

Reviewers: eugenis, pcc, rnk

Reviewed By: pcc, rnk

Subscribers: smeenai, rnk, bd1976llvm, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D56516

llvm-svn: 351247
2019-01-15 21:21:01 +00:00
Jonathan Metzman e159a0dd1a [SanitizerCoverage][NFC] Use appendToUsed instead of include
Summary:
Use appendToUsed instead of include to ensure that
SanitizerCoverage's constructors are not stripped.

Also, use isOSBinFormatCOFF() to determine if target
binary format is COFF.

Reviewers: pcc

Reviewed By: pcc

Subscribers: hiraditya

Differential Revision: https://reviews.llvm.org/D56369

llvm-svn: 351118
2019-01-14 21:02:02 +00:00
Benjamin Kramer b17d2136ea Give helper classes/functions local linkage. NFC.
llvm-svn: 351016
2019-01-12 18:36:22 +00:00
James Y Knight 62df5eed16 [opaque pointer types] Remove some calls to generic Type subtype accessors.
That is, remove many of the calls to Type::getNumContainedTypes(),
Type::subtypes(), and Type::getContainedType(N).

I'm not intending to remove these accessors -- they are
useful/necessary in some cases. However, removing the pointee type
from pointers would potentially break some uses, and reducing the
number of calls makes it easier to audit.

llvm-svn: 350835
2019-01-10 16:07:20 +00:00
Florian Hahn 9697d2a764 Revert r350647: "[NewPM] Port tsan"
This patch breaks thread sanitizer on some macOS builders, e.g.
http://green.lab.llvm.org/green/job/clang-stage1-configure-RA/52725/

llvm-svn: 350719
2019-01-09 13:32:16 +00:00
Philip Pfaffe 82f995db75 [NewPM] Port tsan
A straightforward port of tsan to the new PM, following the same path
as D55647.

Differential Revision: https://reviews.llvm.org/D56433

llvm-svn: 350647
2019-01-08 19:21:57 +00:00
Chandler Carruth 57578aaf96 [CallSite removal] Port `IndirectCallSiteVisitor` to use `CallBase` and
update client code.

Also rename it to use the more generic term `call` instead of something
that could be confused with a praticular type.

Differential Revision: https://reviews.llvm.org/D56183

llvm-svn: 350508
2019-01-07 07:15:51 +00:00
Evgeniy Stepanov 0184c53cbd Revert "Revert "[hwasan] Android: Switch from TLS_SLOT_TSAN(8) to TLS_SLOT_SANITIZER(6)""
This reapplies commit r348983.

llvm-svn: 350448
2019-01-05 00:44:58 +00:00
Peter Collingbourne 87f477b5e4 hwasan: Implement lazy thread initialization for the interceptor ABI.
The problem is similar to D55986 but for threads: a process with the
interceptor hwasan library loaded might have some threads started by
instrumented libraries and some by uninstrumented libraries, and we
need to be able to run instrumented code on the latter.

The solution is to perform per-thread initialization lazily. If a
function needs to access shadow memory or add itself to the per-thread
ring buffer its prologue checks to see whether the value in the
sanitizer TLS slot is null, and if so it calls __hwasan_thread_enter
and reloads from the TLS slot. The runtime does the same thing if it
needs to access this data structure.

This change means that the code generator needs to know whether we
are targeting the interceptor runtime, since we don't want to pay
the cost of lazy initialization when targeting a platform with native
hwasan support. A flag -fsanitize-hwaddress-abi={interceptor,platform}
has been introduced for selecting the runtime ABI to target. The
default ABI is set to interceptor since it's assumed that it will
be more common that users will be compiling application code than
platform code.

Because we can no longer assume that the TLS slot is initialized,
the pthread_create interceptor is no longer necessary, so it has
been removed.

Ideally, lazy initialization should only cost one instruction in the
hot path, but at present the call may cause us to spill arguments
to the stack, which means more instructions in the hot path (or
theoretically in the cold path if the spills are moved with shrink
wrapping). With an appropriately chosen calling convention for
the per-thread initialization function (TODO) the hot path should
always need just one instruction and the cold path should need two
instructions with no spilling required.

Differential Revision: https://reviews.llvm.org/D56038

llvm-svn: 350429
2019-01-04 19:27:04 +00:00
Philip Pfaffe b39a97c8f6 [NewPM] Port Msan
Summary:
Keeping msan a function pass requires replacing the module level initialization:
That means, don't define a ctor function which calls __msan_init, instead just
declare the init function at the first access, and add that to the global ctors
list.

Changes:
- Pull the actual sanitizer and the wrapper pass apart.
- Add a newpm msan pass. The function pass inserts calls to runtime
  library functions, for which it inserts declarations as necessary.
- Update tests.

Caveats:
- There is one test that I dropped, because it specifically tested the
  definition of the ctor.

Reviewers: chandlerc, fedor.sergeev, leonardchan, vitalybuka

Subscribers: sdardis, nemanjai, javed.absar, hiraditya, kbarton, bollu, atanasyan, jsji

Differential Revision: https://reviews.llvm.org/D55647

llvm-svn: 350305
2019-01-03 13:42:44 +00:00
Alexander Potapenko cea4f83371 [MSan] Handle llvm.is.constant intrinsic
MSan used to report false positives in the case the argument of
llvm.is.constant intrinsic was uninitialized.
In fact checking this argument is unnecessary, as the intrinsic is only
used at compile time, and its value doesn't depend on the value of the
argument.

llvm-svn: 350173
2018-12-31 09:42:23 +00:00
Eugene Leviant 4dc3a3f746 [HWASAN] Instrument memorty intrinsics by default
Differential revision: https://reviews.llvm.org/D55926

llvm-svn: 350055
2018-12-24 16:02:48 +00:00
Vedant Kumar b264d69de7 [IR] Add Instruction::isLifetimeStartOrEnd, NFC
Instruction::isLifetimeStartOrEnd() checks whether an Instruction is an
llvm.lifetime.start or an llvm.lifetime.end intrinsic.

This was suggested as a cleanup in D55967.

Differential Revision: https://reviews.llvm.org/D56019

llvm-svn: 349964
2018-12-21 21:49:40 +00:00
Alexander Potapenko 0e3b85a730 [MSan] Don't emit __msan_instrument_asm_load() calls
LLVM treats void* pointers passed to assembly routines as pointers to
sized types.
We used to emit calls to __msan_instrument_asm_load() for every such
void*, which sometimes led to false positives.
A less error-prone (and truly "conservative") approach is to unpoison
only assembly output arguments.

llvm-svn: 349734
2018-12-20 10:05:00 +00:00
Eugene Leviant 2d98eb1b2e [HWASAN] Add support for memory intrinsics
Differential revision: https://reviews.llvm.org/D55117

llvm-svn: 349728
2018-12-20 09:04:33 +00:00
Vitaly Buka 07a55f27dc [asan] Undo special treatment of linkonce_odr and weak_odr
Summary:
On non-Windows these are already removed by ShouldInstrumentGlobal.
On Window we will wait until we get actual issues with that.

Reviewers: pcc

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55899

llvm-svn: 349707
2018-12-20 00:30:27 +00:00
Vitaly Buka d414e1bbb5 [asan] Prevent folding of globals with redzones
Summary:
ICF prevented by removing unnamed_addr and local_unnamed_addr for all sanitized
globals.
Also in general unnamed_addr is not valid here as address now is important for
ODR violation detector and redzone poisoning.

Before the patch ICF on globals caused:
1. false ODR reports when we register global on the same address more than once
2. globals buffer overflow if we fold variables of smaller type inside of large
type. Then the smaller one will poison redzone which overlaps with the larger one.

Reviewers: eugenis, pcc

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55857

llvm-svn: 349706
2018-12-20 00:30:18 +00:00
Vitaly Buka 4e4920694c [asan] Restore ODR-violation detection on vtables
Summary:
unnamed_addr is still useful for detecting of ODR violations on vtables

Still unnamed_addr with lld and --icf=safe or --icf=all can trigger false
reports which can be avoided with --icf=none or by using private aliases
with -fsanitize-address-use-odr-indicator

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: kubamracek, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55799

llvm-svn: 349555
2018-12-18 22:23:30 +00:00
Kuba Mracek 3760fc9f3d [asan] In llvm.asan.globals, allow entries to be non-GlobalVariable and skip over them
Looks like there are valid reasons why we need to allow bitcasts in llvm.asan.globals, see discussion at https://github.com/apple/swift-llvm/pull/133. Let's look through bitcasts when iterating over entries in the llvm.asan.globals list.

Differential Revision: https://reviews.llvm.org/D55794

llvm-svn: 349544
2018-12-18 21:20:17 +00:00
Peter Collingbourne d3a3e4b46d hwasan: Move ctor into a comdat.
Differential Revision: https://reviews.llvm.org/D55733

llvm-svn: 349413
2018-12-17 22:56:34 +00:00
Kamil Rytarowski 21e270a479 Add NetBSD support in needsRuntimeRegistrationOfSectionRange.
Use linker script magic to get data/cnts/name start/end.

llvm-svn: 349277
2018-12-15 16:51:35 +00:00
Kamil Rytarowski 15ae738bc8 Register kASan shadow offset for NetBSD/amd64
The NetBSD x86_64 kernel uses the 0xdfff900000000000 shadow
offset.

llvm-svn: 349276
2018-12-15 16:32:41 +00:00
Evgeniy Stepanov eb238ecf0f Revert "[hwasan] Android: Switch from TLS_SLOT_TSAN(8) to TLS_SLOT_SANITIZER(6)"
Breaks sanitizer-android buildbot.

This reverts commit af8443a984c3b491c9ca2996b8d126ea31e5ecbe.

llvm-svn: 349092
2018-12-13 23:47:50 +00:00
Vitaly Buka a257639a69 [asan] Don't check ODR violations for particular types of globals
Summary:
private and internal: should not trigger ODR at all.
unnamed_addr: current ODR checking approach fail and rereport false violation if
a linker merges such globals
linkonce_odr, weak_odr: could cause similar problems and they are already not
instrumented for ELF.

Reviewers: eugenis, kcc

Subscribers: kubamracek, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55621

llvm-svn: 349015
2018-12-13 09:47:39 +00:00
Ryan Prichard e028c818f5 [hwasan] Android: Switch from TLS_SLOT_TSAN(8) to TLS_SLOT_SANITIZER(6)
Summary:
The change is needed to support ELF TLS in Android. See D55581 for the
same change in compiler-rt.

Reviewers: srhines, eugenis

Reviewed By: eugenis

Subscribers: srhines, llvm-commits

Differential Revision: https://reviews.llvm.org/D55592

llvm-svn: 348983
2018-12-12 22:45:06 +00:00
Adrian Prantl fbeeac0e1e Reapply "Adapt gcov to changes in CFE."
This reverts commit r348203 and reapplies D55085 with an additional
GCOV bugfix to make the change NFC for relative file paths in .gcno files.

Thanks to Ilya Biryukov for additional testing!

Original commit message:

    Update Diagnostic handling for changes in CFE.

    The clang frontend no longer emits the current working directory for
    DIFiles containing an absolute path in the filename: and will move the
    common prefix between current working directory and the file into the
    directory: component.

    https://reviews.llvm.org/D55085

llvm-svn: 348512
2018-12-06 18:44:48 +00:00
Vitaly Buka 8076c57fd2 [asan] Add clang flag -fsanitize-address-use-odr-indicator
Reviewers: eugenis, m.ostapenko, ygribov

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55157

llvm-svn: 348327
2018-12-05 01:44:31 +00:00
Vitaly Buka d6bab09b4b [asan] Split -asan-use-private-alias to -asan-use-odr-indicator
Reviewers: eugenis, m.ostapenko, ygribov

Subscribers: mehdi_amini, kubamracek, hiraditya, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D55156

llvm-svn: 348316
2018-12-04 23:17:41 +00:00
Ilya Biryukov 449a7f0dbb Revert "Adapt gcov to changes in CFE."
This reverts commit r348203.
Reason: this produces absolute paths in .gcno files, breaking us
internally as we rely on them being consistent with the filenames passed
in the command line.

Also reverts r348157 and r348155 to account for revert of r348154 in
clang repository.

llvm-svn: 348279
2018-12-04 16:30:31 +00:00
Vitaly Buka 537cfc0352 [asan] Reduce binary size by using unnamed private aliases
Summary:
--asan-use-private-alias increases binary sizes by 10% or more.
Most of this space was long names of aliases and new symbols.
These symbols are not needed for the ODC check at all.

Reviewers: eugenis

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55146

llvm-svn: 348221
2018-12-04 00:36:14 +00:00
Adrian Prantl 40eb622325 Adapt gcov to changes in CFE.
The clang frontend no longer emits the current working directory for
DIFiles containing an absolute path in the filename: and will move the
common prefix between current working directory and the file into the
directory: component.

This fixes the GCOV tests in compiler-rt that were broken by the Clang
change.

llvm-svn: 348203
2018-12-03 22:37:48 +00:00
Alexander Potapenko 7502e5fc56 [KMSAN] Enable -msan-handle-asm-conservative by default
This change enables conservative assembly instrumentation in KMSAN builds
by default.
It's still possible to disable it with -msan-handle-asm-conservative=0
if something breaks. It's now impossible to enable conservative
instrumentation for userspace builds, but it's not used anyway.

llvm-svn: 348112
2018-12-03 10:15:43 +00:00
Vedant Kumar e7b789b529 [ProfileSummary] Standardize methods and fix comment
Every Analysis pass has a get method that returns a reference of the Result of
the Analysis, for example, BlockFrequencyInfo
&BlockFrequencyInfoWrapperPass::getBFI().  I believe that
ProfileSummaryInfo::getPSI() is the only exception to that, as it was returning
a pointer.

Another change is renaming isHotBB and isColdBB to isHotBlock and isColdBlock,
respectively.  Most methods use BB as the argument of variable names while
methods usually refer to Basic Blocks as Blocks, instead of BB.  For example,
Function::getEntryBlock, Loop:getExitBlock, etc.

I also fixed one of the comments.

Patch by Rodrigo Caetano Rocha!

Differential Revision: https://reviews.llvm.org/D54669

llvm-svn: 347182
2018-11-19 05:23:16 +00:00
Fangrui Song 7570932977 Use llvm::copy. NFC
llvm-svn: 347126
2018-11-17 01:44:25 +00:00
Calixte Denizet c6fabeac11 [GCOV] Add options to filter files which must be instrumented.
Summary:
When making code coverage, a lot of files (like the ones coming from /usr/include) are removed when post-processing gcno/gcda so finally they doen't need to be instrumented nor to appear in gcno/gcda.
The goal of the patch is to be able to filter the files we want to instrument, there are several advantages to do that:
- improve speed (no overhead due to instrumentation on files we don't care)
- reduce gcno/gcda size
- it gives the possibility to easily instrument only few files (e.g. ones modified in a patch) without changing the build system
- need to accept this patch to be enabled in clang: https://reviews.llvm.org/D52034

Reviewers: marco-c, vsk

Reviewed By: marco-c

Subscribers: llvm-commits, sylvestre.ledru

Differential Revision: https://reviews.llvm.org/D52033

llvm-svn: 346641
2018-11-12 09:01:43 +00:00
Reid Kleckner b41b372171 [sancov] Put .SCOV* sections into the right comdat groups on COFF
Avoids linker errors about relocations against discarded sections.

This was uncovered during the Chromium clang roll here:
https://chromium-review.googlesource.com/c/chromium/src/+/1321863#message-717516acfcf829176f6a2f50980f7a4bdd66469a

After this change, Chromium's libGLESv2 links successfully for me.

Reviewers: metzman, hans, morehouse

Differential Revision: https://reviews.llvm.org/D54232

llvm-svn: 346381
2018-11-08 00:57:33 +00:00
Rong Xu fb4bcc452c [PGO] Exit early if all count values are zero
If all the edge counts for a function are zero, skip count population and
annotation, as nothing will happen. This can save some compile time.

Differential Revision: https://reviews.llvm.org/D54212

llvm-svn: 346370
2018-11-07 23:51:20 +00:00
Calixte Denizet c3bed1e8e6 [GCOV] Flush counters before to avoid counting the execution before fork twice and for exec** functions we must flush before the call
Summary:
This is replacement for patch in https://reviews.llvm.org/D49460.
When we fork, the counters are duplicate as they're and so the values are finally wrong when writing gcda for parent and child.
So just before to fork, we flush the counters and so the parent and the child have new counters set to zero.
For exec** functions, we need to flush before the call to have some data.

Reviewers: vsk, davidxl, marco-c

Reviewed By: marco-c

Subscribers: llvm-commits, sylvestre.ledru, marco-c

Differential Revision: https://reviews.llvm.org/D53593

llvm-svn: 346313
2018-11-07 13:49:17 +00:00
Alexander Potapenko c1c4c9a494 [MSan] another take at instrumenting inline assembly - now with calls
Turns out it's not always possible to figure out whether an asm()
statement argument points to a valid memory region.
One example would be per-CPU objects in the Linux kernel, for which the
addresses are calculated using the FS register and a small offset in the
.data..percpu section.
To avoid pulling all sorts of checks into the instrumentation, we replace
actual checking/unpoisoning code with calls to
msan_instrument_asm_load(ptr, size) and
msan_instrument_asm_store(ptr, size) functions in the runtime.

This patch doesn't implement the runtime hooks in compiler-rt, as there's
been no demand in assembly instrumentation for userspace apps so far.

llvm-svn: 345702
2018-10-31 09:32:47 +00:00
Calixte Denizet 38d50545fe [GCOV] Function counters are wrong when on one line
Summary:
After commit https://reviews.llvm.org/rL344228, the function definitions have a counter but when on one line the counter is wrong (e.g. void foo() { })
I added a test in: https://reviews.llvm.org/D53601

Reviewers: marco-c

Reviewed By: marco-c

Subscribers: llvm-commits, sylvestre.ledru

Differential Revision: https://reviews.llvm.org/D53600

llvm-svn: 345624
2018-10-30 18:41:31 +00:00
Leonard Chan eebecb3214 Revert "[PassManager/Sanitizer] Enable usage of ported AddressSanitizer passes with -fsanitize=address"
This reverts commit 8d6af840396f2da2e4ed6aab669214ae25443204 and commit
b78d19c287b6e4a9abc9fb0545de9a3106d38d3d which causes slower build times
by initializing the AddressSanitizer on every function run.

The corresponding revisions are https://reviews.llvm.org/D52814 and
https://reviews.llvm.org/D52739.

llvm-svn: 345433
2018-10-26 22:51:51 +00:00
Kostya Serebryany af95597c3c [hwasan] add stack frame descriptions.
Summary:
At compile-time, create an array of {PC,HumanReadableStackFrameDescription}
for every function that has an instrumented frame, and pass this array
to the run-time at the module-init time.
Similar to how we handle pc-table in SanitizerCoverage.
The run-time is dummy, will add the actual logic in later commits.

Reviewers: morehouse, eugenis

Reviewed By: eugenis

Subscribers: srhines, llvm-commits, kubamracek

Differential Revision: https://reviews.llvm.org/D53227

llvm-svn: 344985
2018-10-23 00:50:40 +00:00
Benjamin Kramer 3e778165d6 [CGProfile] Turn constant-size SmallVector into array
No functionality change.

llvm-svn: 344893
2018-10-22 10:51:34 +00:00
Leonard Chan 423957ad3a [Sanitizer][PassManager] Fix for failing ASan tests on arm-linux-gnueabihf
Forgot to initialize the legacy pass in it's constructor.

Differential Revision: https://reviews.llvm.org/D53350

llvm-svn: 344659
2018-10-17 00:16:07 +00:00
Jonathan Metzman 5eb8cba280 [SanitizerCoverage] Don't duplicate code to get section pointers
Summary:
Merge code used to get section start and section end pointers
for SanitizerCoverage constructors. This includes code that handles
getting the start pointers when targeting MSVC.

Reviewers: kcc, morehouse

Reviewed By: morehouse

Subscribers: kcc, hiraditya

Differential Revision: https://reviews.llvm.org/D53211

llvm-svn: 344657
2018-10-16 23:43:57 +00:00
Chandler Carruth edb12a838a [TI removal] Make variables declared as `TerminatorInst` and initialized
by `getTerminator()` calls instead be declared as `Instruction`.

This is the biggest remaining chunk of the usage of `getTerminator()`
that insists on the narrow type and so is an easy batch of updates.
Several files saw more extensive updates where this would cascade to
requiring API updates within the file to use `Instruction` instead of
`TerminatorInst`. All of these were trivial in nature (pervasively using
`Instruction` instead just worked).

llvm-svn: 344502
2018-10-15 10:04:59 +00:00
Chandler Carruth 4a2d58e16a [TI removal] Remove `TerminatorInst` from BasicBlockUtils.h
This requires updating a number of .cpp files to adapt to the new API.
I've just systematically updated all uses of `TerminatorInst` within
these files te `Instruction` so thta I won't have to touch them again in
the future.

llvm-svn: 344498
2018-10-15 09:34:05 +00:00
Benjamin Kramer c55e997556 Move some helpers from the global namespace into anonymous ones.
llvm-svn: 344468
2018-10-13 22:18:22 +00:00
Kostya Serebryany bc504559ec move GetOrCreateFunctionComdat to Instrumentation.cpp/Instrumentation.h
Summary:
GetOrCreateFunctionComdat is currently used in SanitizerCoverage,
where it's defined. I'm planing to use it in HWASAN as well,
so moving it into a common location.
NFC

Reviewers: morehouse

Reviewed By: morehouse

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D53218

llvm-svn: 344433
2018-10-12 23:21:48 +00:00
Jonathan Metzman 0b94e88007 [SanitizerCoverage] Prevent /OPT:REF from stripping constructors
Summary:
Linking with the /OPT:REF linker flag when building COFF files causes
the linker to strip SanitizerCoverage's constructors. Prevent this by
giving the constructors WeakODR linkage and by passing the linker a
directive to include sancov.module_ctor.

Include a test in compiler-rt to verify libFuzzer can be linked using
/OPT:REF

Reviewers: morehouse, rnk

Reviewed By: morehouse, rnk

Subscribers: rnk, morehouse, hiraditya

Differential Revision: https://reviews.llvm.org/D52119

llvm-svn: 344391
2018-10-12 18:11:47 +00:00
Max Moroz 4d010ca35b [SanitizerCoverage] Make Inline8bit and TracePC counters dead stripping resistant.
Summary:
Otherwise, at least on Mac, the linker eliminates unused symbols which
causes libFuzzer to error out due to a mismatch of the sizes of coverage tables.

Issue in Chromium: https://bugs.chromium.org/p/chromium/issues/detail?id=892167

Reviewers: morehouse, kcc, george.karpenkov

Reviewed By: morehouse

Subscribers: kubamracek, llvm-commits

Differential Revision: https://reviews.llvm.org/D53113

llvm-svn: 344345
2018-10-12 13:59:31 +00:00
Kostya Serebryany d891ac9794 merge two near-identical functions createPrivateGlobalForString into one
Summary:
We have two copies of createPrivateGlobalForString (in asan and in esan).
This change merges them into one. NFC

Reviewers: vitalybuka

Reviewed By: vitalybuka

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D53178

llvm-svn: 344314
2018-10-11 23:03:27 +00:00
Leonard Chan 64e21b5cfd [PassManager/Sanitizer] Port of AddresSanitizer pass from legacy to new PassManager
This patch ports the legacy pass manager to the new one to take advantage of
the benefits of the new PM. This involved moving a lot of the declarations for
`AddressSantizer` to a header so that it can be publicly used via
PassRegistry.def which I believe contains all the passes managed by the new PM.

This patch essentially decouples the instrumentation from the legacy PM such
hat it can be used by both legacy and new PM infrastructure.

Differential Revision: https://reviews.llvm.org/D52739

llvm-svn: 344274
2018-10-11 18:31:51 +00:00
Calixte Denizet d2f290b034 [gcov] Display the hit counter for the line of a function definition
Summary:
Right now there is no hit counter on the line of function.
So the idea is add the line of the function to all the lines covered by the entry block.
Tests in compiler-rt/profile will be fixed in another patch: https://reviews.llvm.org/D49854

Reviewers: marco-c, davidxl

Reviewed By: marco-c

Subscribers: sylvestre.ledru, llvm-commits

Differential Revision: https://reviews.llvm.org/D49853

llvm-svn: 344228
2018-10-11 08:53:43 +00:00
Richard Smith 6c67662816 Add a flag to remap manglings when reading profile data information.
This can be used to preserve profiling information across codebase
changes that have widespread impact on mangled names, but across which
most profiling data should still be usable. For example, when switching
from libstdc++ to libc++, or from the old libstdc++ ABI to the new ABI,
or even from a 32-bit to a 64-bit build.

The user can provide a remapping file specifying parts of mangled names
that should be treated as equivalent (eg, std::__1 should be treated as
equivalent to std::__cxx11), and profile data will be treated as
applying to a particular function if its name is equivalent to the name
of a function in the profile data under the provided equivalences. See
the documentation change for a description of how this is configured.

Remapping is supported for both sample-based profiling and instruction
profiling. We do not support remapping indirect branch target
information, but all other profile data should be remapped
appropriately.

Support is only added for the new pass manager. If someone wants to also
add support for this for the old pass manager, doing so should be
straightforward.

This is the LLVM side of Clang r344199.

Reviewers: davidxl, tejohnson, dlj, erik.pilkington

Subscribers: mehdi_amini, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D51249

llvm-svn: 344200
2018-10-10 23:13:47 +00:00
Fangrui Song 3507c6e884 Use the container form llvm::sort(C, ...)
There are a few leftovers in rL343163 which span two lines. This commit
changes these llvm::sort(C.begin(), C.end, ...) to llvm::sort(C, ...)

llvm-svn: 343426
2018-09-30 22:31:29 +00:00
Vitaly Buka 0509070811 [cxx2a] Fix warning triggered by r343285
llvm-svn: 343369
2018-09-29 02:17:12 +00:00
Evgeniy Stepanov 090f0f9504 [hwasan] Record and display stack history in stack-based reports.
Summary:
Display a list of recent stack frames (not a stack trace!) when
tag-mismatch is detected on a stack address.

The implementation uses alignment tricks to get both the address of
the history buffer, and the base address of the shadow with a single
8-byte load. See the comment in hwasan_thread_list.h for more
details.

Developed in collaboration with Kostya Serebryany.

Reviewers: kcc

Subscribers: srhines, kubamracek, mgorny, hiraditya, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D52249

llvm-svn: 342923
2018-09-24 23:03:34 +00:00
Evgeniy Stepanov 20c4999e8b Revert "[hwasan] Record and display stack history in stack-based reports."
This reverts commit r342921: test failures on clang-cmake-arm* bots.

llvm-svn: 342922
2018-09-24 22:50:32 +00:00
Evgeniy Stepanov 9043e17edd [hwasan] Record and display stack history in stack-based reports.
Summary:
Display a list of recent stack frames (not a stack trace!) when
tag-mismatch is detected on a stack address.

The implementation uses alignment tricks to get both the address of
the history buffer, and the base address of the shadow with a single
8-byte load. See the comment in hwasan_thread_list.h for more
details.

Developed in collaboration with Kostya Serebryany.

Reviewers: kcc

Subscribers: srhines, kubamracek, mgorny, hiraditya, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D52249

llvm-svn: 342921
2018-09-24 21:38:42 +00:00
Calixte Denizet eb7f60201c [IR] Add a boolean field in DILocation to know if a line must covered or not
Summary:
Some lines have a hit counter where they should not have one.
For example, in C++, some cleanup is adding at the end of a scope represented by a '}'.
So such a line has a hit counter where a user expects to not have one.
The goal of the patch is to add this information in DILocation which is used to get the covered lines in GCOVProfiling.cpp.
A following patch in clang will add this information when generating IR (https://reviews.llvm.org/D49916).

Reviewers: marco-c, davidxl, vsk, javed.absar, rnk

Reviewed By: rnk

Subscribers: eraman, xur, danielcdh, aprantl, rnk, dblaikie, #debug-info, vsk, llvm-commits, sylvestre.ledru

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D49915

llvm-svn: 342631
2018-09-20 08:53:06 +00:00
Hiroshi Yamauchi fd2c699dd6 [PGO][CHR] Add opt remarks.
Reviewers: davidxl

Reviewed By: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D52056

llvm-svn: 342495
2018-09-18 16:50:10 +00:00
Matt Morehouse 3bea25e554 [SanitizerCoverage] Create comdat for global arrays.
Summary:
Place global arrays in comdat sections with their associated functions.
This makes sure they are stripped along with the functions they
reference, even on the BFD linker.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D51902

llvm-svn: 342186
2018-09-13 21:45:55 +00:00
Matt Morehouse f0d7daa972 Revert "[SanitizerCoverage] Create comdat for global arrays."
This reverts r341987 since it will cause trouble when there's a module
ID collision.

llvm-svn: 341995
2018-09-11 21:15:41 +00:00
Matt Morehouse 7ce6032432 [SanitizerCoverage] Create comdat for global arrays.
Summary:
Place global arrays in comdat sections with their associated functions.
This makes sure they are stripped along with the functions they
reference, even on the BFD linker.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D51902

llvm-svn: 341987
2018-09-11 20:10:40 +00:00
Vedant Kumar 727d89526e [gcov] Fix branch counters with switch statements (fix PR38821)
Right now, the counters are added in regards of the number of successors
for a given BasicBlock: it's good when we've only 1 or 2 successors (at
least with BranchInstr). But in the case of a switch statement, the
BasicBlock after switch has several predecessors and we need know from
which BB we're coming from.

So the idea is to revert what we're doing: add a PHINode in each block
which will select the counter according to the incoming BB.  They're
several pros for doing that:

- we fix the "switch" bug
- we remove the function call to "__llvm_gcov_indirect_counter_increment"
  and the lookup table stuff
- we replace by PHINodes, so the optimizer will probably makes a better
  job.

Patch by calixte!

Differential Revision: https://reviews.llvm.org/D51619

llvm-svn: 341977
2018-09-11 18:38:34 +00:00
Matt Morehouse 40fbdd0c4f Revert "[SanitizerCoverage] Create comdat for global arrays."
This reverts r341951 due to bot breakage.

llvm-svn: 341965
2018-09-11 17:20:14 +00:00
Matt Morehouse eac270caf4 [SanitizerCoverage] Create comdat for global arrays.
Summary:
Place global arrays in comdat sections with their associated functions.
This makes sure they are stripped along with the functions they
reference, even on the BFD linker.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D51902

llvm-svn: 341951
2018-09-11 15:23:14 +00:00
Fangrui Song b3b61de09a [PGO] Fix some style issue of ControlHeightReduction
Reviewers: yamauchi

Reviewed By: yamauchi

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D51811

llvm-svn: 341702
2018-09-07 20:23:15 +00:00
Hiroshi Yamauchi 06650941a2 [PGO][CHR] Build/warning fix
llvm-svn: 341692
2018-09-07 18:44:53 +00:00
Hiroshi Yamauchi 5fb509b763 [PGO][CHR] Small cleanup.
Summary:
Do away with demangling. It wasn't really necessary.
Declared some local functions to be static.

Reviewers: davidxl

Reviewed By: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D51740

llvm-svn: 341681
2018-09-07 18:00:58 +00:00
Alexander Potapenko 6301574cb4 [MSan] don't access MsanCtorFunction when using KMSAN
MSan has found a use of uninitialized memory in MSan, fix it.

llvm-svn: 341646
2018-09-07 09:56:36 +00:00
Alexander Potapenko 8fe99a0ef2 [MSan] Add KMSAN instrumentation to MSan pass
Introduce the -msan-kernel flag, which enables the kernel instrumentation.

The main differences between KMSAN and MSan instrumentations are:

- KMSAN implies msan-track-origins=2, msan-keep-going=true;
- there're no explicit accesses to shadow and origin memory.
  Shadow and origin values for a particular X-byte memory location are
  read and written via pointers returned by
  __msan_metadata_ptr_for_load_X(u8 *addr) and
  __msan_store_shadow_origin_X(u8 *addr, uptr shadow, uptr origin);
- TLS variables are stored in a single struct in per-task storage. A call
  to a function returning that struct is inserted into every instrumented
  function before the entry block;
- __msan_warning() takes a 32-bit origin parameter;
- local variables are poisoned with __msan_poison_alloca() upon function
  entry and unpoisoned with __msan_unpoison_alloca() before leaving the
  function;
- the pass doesn't declare any global variables or add global constructors
  to the translation unit.

llvm-svn: 341637
2018-09-07 09:10:30 +00:00
Alexander Potapenko 7f270fcf0a [MSan] store origins for variadic function parameters in __msan_va_arg_origin_tls
Add the __msan_va_arg_origin_tls TLS array to keep the origins for variadic function parameters.
Change the instrumentation pass to store parameter origins in this array.

This is a reland of r341528.

test/msan/vararg.cc doesn't work on Mips, PPC and AArch64 (because this
patch doesn't touch them), XFAIL these arches.
Also turned out Clang crashed on i80 vararg arguments because of
incorrect origin type returned by getOriginPtrForVAArgument() - fixed it
and added a test.

llvm-svn: 341554
2018-09-06 15:14:36 +00:00
Alexander Potapenko ac6595bd53 [MSan] revert r341528 to unbreak the bots
llvm-svn: 341541
2018-09-06 12:19:27 +00:00
Alexander Potapenko 1a10ae0def [MSan] store origins for variadic function parameters in __msan_va_arg_origin_tls
Add the __msan_va_arg_origin_tls TLS array to keep the origins for
variadic function parameters.
Change the instrumentation pass to store parameter origins in this array.

llvm-svn: 341528
2018-09-06 08:50:11 +00:00
Alexander Potapenko d518c5fc87 [MSan] Make sure variadic function arguments do not overflow __msan_va_arg_tls
Turns out that calling a variadic function with too many (e.g. >100 i64's)
arguments overflows __msan_va_arg_tls, which leads to smashing other TLS
data with function argument shadow values.

getShadow() already checks for kParamTLSSize and returns clean shadow if
the argument does not fit, so just skip storing argument shadow for such
arguments.

llvm-svn: 341525
2018-09-06 08:21:54 +00:00
Benjamin Kramer 9abad4814d [ControlHeightReduction] Remove unused includes
Also clang-format them.

llvm-svn: 341468
2018-09-05 13:51:05 +00:00
Richard Trieu 47c2bc58b3 Prevent unsigned overflow.
The sum of the weights is caculated in an APInt, which has a width smaller than
64.  In certain cases, the sum of the widths would overflow when calculations
are done inside an APInt, but would not if done with uint64_t.  Since the
values will be passed as uint64_t in the function call anyways, do all the math
in 64 bits.  Also added an assert in case the probabilities overflow 64 bits.

llvm-svn: 341444
2018-09-05 04:19:15 +00:00
Fangrui Song c8f348cba7 Fix -Wunused-function in release build after rL341386
llvm-svn: 341443
2018-09-05 03:10:20 +00:00
Hiroshi Yamauchi bd897a02a0 Fix a memory leak after rL341386.
Reviewers: davidxl

Reviewed By: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D51658

llvm-svn: 341412
2018-09-04 21:28:22 +00:00
Reid Kleckner 792a4f8a21 Fix unused variable warning
llvm-svn: 341400
2018-09-04 20:34:47 +00:00
Hiroshi Yamauchi 72ee6d6000 Fix build failures after rL341386.
Reviewers: davidxl

Reviewed By: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D51647

llvm-svn: 341391
2018-09-04 18:10:54 +00:00
Hiroshi Yamauchi 9775a620b0 [PGO] Control Height Reduction
Summary:
Control height reduction merges conditional blocks of code and reduces the
number of conditional branches in the hot path based on profiles.

if (hot_cond1) { // Likely true.
  do_stg_hot1();
}
if (hot_cond2) { // Likely true.
  do_stg_hot2();
}

->

if (hot_cond1 && hot_cond2) { // Hot path.
  do_stg_hot1();
  do_stg_hot2();
} else { // Cold path.
  if (hot_cond1) {
    do_stg_hot1();
  }
  if (hot_cond2) {
    do_stg_hot2();
  }
}

This speeds up some internal benchmarks up to ~30%.

Reviewers: davidxl

Reviewed By: davidxl

Subscribers: xbolva00, dmgreen, mehdi_amini, llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D50591

llvm-svn: 341386
2018-09-04 17:19:13 +00:00
Matt Morehouse 7e042bb1d1 [libFuzzer] Port to Windows
Summary:
Port libFuzzer to windows-msvc.
This patch allows libFuzzer targets to be built and run on Windows, using -fsanitize=fuzzer and/or fsanitize=fuzzer-no-link. It allows these forms of coverage instrumentation to work on Windows as well.
It does not fix all issues, such as those with -fsanitize-coverage=stack-depth, which is not usable on Windows as of this patch.
It also does not fix any libFuzzer integration tests. Nearly all of them fail to compile, fixing them will come in a later patch, so libFuzzer tests are disabled on Windows until them.

Patch By: metzman

Reviewers: morehouse, rnk

Reviewed By: morehouse, rnk

Subscribers: #sanitizers, delcypher, morehouse, kcc, eraman

Differential Revision: https://reviews.llvm.org/D51022

llvm-svn: 341082
2018-08-30 15:54:44 +00:00
Matt Morehouse cf311cfc20 Revert "[libFuzzer] Port to Windows"
This reverts r340949 due to bot breakage again.

llvm-svn: 340954
2018-08-29 18:40:41 +00:00
Matt Morehouse 245ebd71ef [libFuzzer] Port to Windows
Summary:
Port libFuzzer to windows-msvc.
This patch allows libFuzzer targets to be built and run on Windows, using -fsanitize=fuzzer and/or fsanitize=fuzzer-no-link. It allows these forms of coverage instrumentation to work on Windows as well.
It does not fix all issues, such as those with -fsanitize-coverage=stack-depth, which is not usable on Windows as of this patch.
It also does not fix any libFuzzer integration tests. Nearly all of them fail to compile, fixing them will come in a later patch, so libFuzzer tests are disabled on Windows until them.

Reviewers: morehouse, rnk

Reviewed By: morehouse, rnk

Subscribers: #sanitizers, delcypher, morehouse, kcc, eraman

Differential Revision: https://reviews.llvm.org/D51022

llvm-svn: 340949
2018-08-29 18:08:34 +00:00
Matt Morehouse bab8556f01 Revert "[libFuzzer] Port to Windows"
This reverts commit r340860 due to failing tests.

llvm-svn: 340867
2018-08-28 19:07:24 +00:00
Matt Morehouse c6fff3b6f5 [libFuzzer] Port to Windows
Summary:
Port libFuzzer to windows-msvc.
This patch allows libFuzzer targets to be built and run on Windows, using -fsanitize=fuzzer and/or fsanitize=fuzzer-no-link. It allows these forms of coverage instrumentation to work on Windows as well.
It does not fix all issues, such as those with -fsanitize-coverage=stack-depth, which is not usable on Windows as of this patch.
It also does not fix any libFuzzer integration tests. Nearly all of them fail to compile, fixing them will come in a later patch, so libFuzzer tests are disabled on Windows until them.

Patch By: metzman

Reviewers: morehouse, rnk

Reviewed By: morehouse, rnk

Subscribers: morehouse, kcc, eraman

Differential Revision: https://reviews.llvm.org/D51022

llvm-svn: 340860
2018-08-28 18:34:32 +00:00
Chandler Carruth 9ae926b973 [IR] Replace `isa<TerminatorInst>` with `isTerminator()`.
This is a bit awkward in a handful of places where we didn't even have
an instruction and now we have to see if we can build one. But on the
whole, this seems like a win and at worst a reasonable cost for removing
`TerminatorInst`.

All of this is part of the removal of `TerminatorInst` from the
`Instruction` type hierarchy.

llvm-svn: 340701
2018-08-26 09:51:22 +00:00
Xinliang David Li bcf726a32d [PGO] add target md5sum in warning message for icall
Differential revision: http://reviews.llvm.org/D51193

llvm-svn: 340657
2018-08-24 21:38:24 +00:00
Alexander Richardson 6bcf2ba2f0 Allow creating llvm::Function in non-zero address spaces
Most users won't have to worry about this as all of the
'getOrInsertFunction' functions on Module will default to the program
address space.

An overload has been added to Function::Create to abstract away the
details for most callers.

This is based on https://reviews.llvm.org/D37054 but without the changes to
make passing a Module to Function::Create() mandatory. I have also added
some more tests and fixed the LLParser to accept call instructions for
types in the program address space.

Reviewed By: bjope

Differential Revision: https://reviews.llvm.org/D47541

llvm-svn: 340519
2018-08-23 09:25:17 +00:00
Reid Kleckner 85a8c12db8 Re-land r334313 "[asan] Instrument comdat globals on COFF targets"
If we can use comdats, then we can make it so that the global metadata
is thrown away if the prevailing definition of the global was
uninstrumented. I have only tested this on COFF targets, but in theory,
there is no reason that we cannot also do this for ELF.

This will allow us to re-enable string merging with ASan on Windows,
reducing the binary size cost of ASan on Windows.

I tested this change with ASan+PGO, and I fixed an issue with the
__llvm_profile_raw_version symbol. With the old version of my patch, we
would attempt to instrument that symbol on ELF because it had a comdat
with external linkage. If we had been using the linker GC-friendly
metadata scheme, everything would have worked, but clang does not enable
it by default.

llvm-svn: 340232
2018-08-20 23:35:45 +00:00
Vedant Kumar ee6c233ae0 [InstrProf] Use atomic profile counter updates for TSan
Thread sanitizer instrumentation fails to skip all loads and stores to
profile counters. This can happen if profile counter updates are merged:

  %.sink = phi i64* ...
  %pgocount5 = load i64, i64* %.sink
  %27 = add i64 %pgocount5, 1
  %28 = bitcast i64* %.sink to i8*
  call void @__tsan_write8(i8* %28)
  store i64 %27, i64* %.sink

To suppress TSan diagnostics about racy counter updates, make the
counter updates atomic when TSan is enabled. If there's general interest
in this mode it can be surfaced as a clang/swift driver option.

Testing: check-{llvm,clang,profile}

rdar://40477803

Differential Revision: https://reviews.llvm.org/D50867

llvm-svn: 339955
2018-08-16 22:24:47 +00:00
Evgeniy Stepanov a265a13bbe [hwasan] Add a basic API.
Summary:
Add user tag manipulation functions:
  __hwasan_tag_memory
  __hwasan_tag_pointer
  __hwasan_print_shadow (very simple and ugly, for now)

Reviewers: vitalybuka, kcc

Subscribers: kubamracek, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D50746

llvm-svn: 339746
2018-08-15 00:39:35 +00:00
Matt Morehouse 0f22fac274 [SanitizerCoverage] Add associated metadata to PC guards.
Summary:
Without this metadata LLD strips unused PC table entries
but won't strip unused guards.  This metadata also seems
to influence the linker to change the ordering in the PC
guard section to match that of the PC table section.

The libFuzzer runtime library depends on the ordering
of the PC table and PC guard sections being the same.  This
is not generally guaranteed, so we may need to redesign
PC tables/guards/counters in the future.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: kcc, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D50483

llvm-svn: 339733
2018-08-14 22:04:34 +00:00
Evgeniy Stepanov 453e7ac785 [hwasan] Add -hwasan-with-ifunc flag.
Summary: Similar to asan's flag, it can be used to disable the use of ifunc to access hwasan shadow address.

Reviewers: vitalybuka, kcc

Subscribers: srhines, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D50544

llvm-svn: 339447
2018-08-10 16:21:37 +00:00
Alexander Potapenko 75a954330b [MSan] Shrink the register save area for non-SSE builds
If code is compiled for X86 without SSE support, the register save area
doesn't contain FPU registers, so `AMD64FpEndOffset` should be equal to
`AMD64GpEndOffset`.

llvm-svn: 339414
2018-08-10 08:06:43 +00:00
Joel Galenson cfe5bc158d Fix crash in bounds checking.
In r337830 I added SCEV checks to enable us to insert fewer bounds checks.  Unfortunately, this sometimes crashes when multiple bounds checks are added due to SCEV caching issues.  This patch splits the bounds checking pass into two phases, one that computes all the conditions (using SCEV checks) and the other that adds the new instructions.

Differential Revision: https://reviews.llvm.org/D49946

llvm-svn: 338902
2018-08-03 17:12:23 +00:00
John Baldwin c5d7e04052 [ASAN] Use the correct shadow offset for ASAN on FreeBSD/mips64.
Reviewed By: atanasyan

Differential Revision: https://reviews.llvm.org/D49939

llvm-svn: 338650
2018-08-01 22:51:13 +00:00
Fangrui Song f78650a8de Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338293
2018-07-30 19:41:25 +00:00
Reid Kleckner ba82788ff6 [InstrProf] Don't register __llvm_profile_runtime_user
Refactor some FileCheck prefixes while I'm at it.

Fixes PR38340

llvm-svn: 338172
2018-07-27 22:21:35 +00:00
Petr Hosek 47e5fcba57 [profile] Support profiling runtime on Fuchsia
This ports the profiling runtime on Fuchsia and enables the
instrumentation. Unlike on other platforms, Fuchsia doesn't use
files to dump the instrumentation data since on Fuchsia, filesystem
may not be accessible to the instrumented process. We instead use
the data sink to pass the profiling data to the system the same
sanitizer runtimes do.

Differential Revision: https://reviews.llvm.org/D47208

llvm-svn: 337881
2018-07-25 03:01:35 +00:00
Joel Galenson 8dbcc58917 Use SCEV to avoid inserting some bounds checks.
This patch uses SCEV to avoid inserting some bounds checks when they are not needed.  This slightly improves the performance of code compiled with the bounds check sanitizer.

Differential Revision: https://reviews.llvm.org/D49602

llvm-svn: 337830
2018-07-24 15:21:54 +00:00
Alexander Potapenko 80c6f41581 [MSan] Hotfix compilation
Make sure NewSI is used in materializeStores()

llvm-svn: 337577
2018-07-20 16:52:12 +00:00
Alexander Potapenko 5ff3abbc31 [MSan] run materializeChecks() before materializeStores()
When pointer checking is enabled, it's important that every pointer is
checked before its value is used.
For stores MSan used to generate code that calculates shadow/origin
addresses from a pointer before checking it.
For userspace this isn't a problem, because the shadow calculation code
is quite simple and compiler is able to move it after the check on -O2.
But for KMSAN getShadowOriginPtr() creates a runtime call, so we want the
check to be performed strictly before that call.

Swapping materializeChecks() and materializeStores() resolves the issue:
both functions insert code before the given IR location, so the new
insertion order guarantees that the code calculating shadow address is
between the address check and the memory access.

llvm-svn: 337571
2018-07-20 16:28:49 +00:00
Peter Collingbourne 4a653fa7f1 Rename __asan_gen_* symbols to ___asan_gen_*.
This prevents gold from printing a warning when trying to export
these symbols via the asan dynamic list after ThinLTO promotes them
from private symbols to external symbols with hidden visibility.

Differential Revision: https://reviews.llvm.org/D49498

llvm-svn: 337428
2018-07-18 22:23:14 +00:00
Alexander Potapenko d1a381b17a MSan: minor fixes, NFC
- remove an extra space after |ID| declaration
 - drop the unused |FirstInsn| parameter in getShadowOriginPtrUserspace()

llvm-svn: 337159
2018-07-16 10:57:19 +00:00
Alexander Potapenko 725a4ddc9e [MSan] factor userspace-specific declarations into createUserspaceApi(). NFC
This patch introduces createUserspaceApi() that creates function/global
declarations for symbols used by MSan in the userspace.
This is a step towards the upcoming KMSAN implementation patch.

Reviewed at https://reviews.llvm.org/D49292

llvm-svn: 337155
2018-07-16 10:03:30 +00:00
Michael J. Spencer 7bb2767fba Recommit r335794 "Add support for generating a call graph profile from Branch Frequency Info." with fix for removed functions.
llvm-svn: 337140
2018-07-16 00:28:24 +00:00
Matt Morehouse 4543816150 [SanitizerCoverage] Add associated metadata to 8-bit counters.
Summary:
This allows counters associated with unused functions to be
dead-stripped along with their functions.  This approach is the same one
we used for PC tables.

Fixes an issue where LLD removes an unused PC table but leaves the 8-bit
counter.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: llvm-commits, hiraditya, kcc

Differential Revision: https://reviews.llvm.org/D49264

llvm-svn: 336941
2018-07-12 20:24:58 +00:00
Ulrich Weigand b961fdc509 [gcov] Fix ABI when calling llvm_gcov_... routines from instrumentation code
The llvm_gcov_... routines in compiler-rt are regular C functions that
need to be called using the proper C ABI for the target. The current
code simply calls them using plain LLVM IR types. Since the type are
mostly simple, this happens to just work on certain targets. But other
targets still need special handling; in particular, it may be necessary
to sign- or zero-extended sub-word values to comply with the ABI. This
caused gcov failures on SystemZ in particular.

Now the very same problem was already fixed for the llvm_profile_ calls
here: https://reviews.llvm.org/D21736

This patch uses the same method to fix the llvm_gcov_ calls, in
particular calls to llvm_gcda_start_file, llvm_gcda_emit_function, and
llvm_gcda_emit_arcs.

Reviewed By: marco-c

Differential Revision: https://reviews.llvm.org/D49134

llvm-svn: 336692
2018-07-10 16:05:47 +00:00
Chijun Sima 9e1e0c7b2a [PGOMemOPSize] Preserve the DominatorTree
Summary:
PGOMemOPSize only modifies CFG in a couple of places; thus we can preserve the DominatorTree with little effort.
When optimizing SQLite with -O3, this patch can decrease 3.8% of the numbers of nodes traversed by DFS and 5.7% of the times DominatorTreeBase::recalculation is called.

Reviewers: kuhar, davide, dmgreen

Reviewed By: dmgreen

Subscribers: mzolotukhin, vsk, llvm-commits

Differential Revision: https://reviews.llvm.org/D48914

llvm-svn: 336522
2018-07-09 08:07:21 +00:00
Alex Shlyapnikov 788764ca12 [HWASan] Do not retag allocas before return from the function.
Summary:
Retagging allocas before returning from the function might help
detecting use after return bugs, but it does not work at all in real
life, when instrumented and non-instrumented code is intermixed.
Consider the following code:

F_non_instrumented() {
  T x;
  F1_instrumented(&x);
  ...
}

{
  F_instrumented();
  F_non_instrumented();
}

- F_instrumented call leaves the stack below the current sp tagged
  randomly for UAR detection
- F_non_instrumented allocates its own vars on that tagged stack,
  not generating any tags, that is the address of x has tag 0, but the
  shadow memory still contains tags left behind by F_instrumented on the
  previous step
- F1_instrumented verifies &x before using it and traps on tag mismatch,
  0 vs whatever tag was set by F_instrumented

Reviewers: eugenis

Subscribers: srhines, llvm-commits

Differential Revision: https://reviews.llvm.org/D48664

llvm-svn: 336011
2018-06-29 20:20:17 +00:00
Benjamin Kramer 269eb21e1c Revert "Add support for generating a call graph profile from Branch Frequency Info."
This reverts commits r335794 and r335797. Breaks ThinLTO+FDO selfhost.

llvm-svn: 335851
2018-06-28 13:15:03 +00:00
Michael J. Spencer 98f5475f44 [CGProfile] Fix unused variable warning.
llvm-svn: 335797
2018-06-28 00:12:04 +00:00
Michael J. Spencer 5bf1ead377 Add support for generating a call graph profile from Branch Frequency Info.
=== Generating the CG Profile ===

The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions.  For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.

After scanning all the functions, it generates an appending module flag containing the data. The format looks like:
```
!llvm.module.flags = !{!0}

!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}
```

Differential Revision: https://reviews.llvm.org/D48105

llvm-svn: 335794
2018-06-27 23:58:08 +00:00
Evgeniy Stepanov 289a7d4c7d Revert "[asan] Instrument comdat globals on COFF targets"
Causes false positive ODR violation reports on __llvm_profile_raw_version.

llvm-svn: 335681
2018-06-26 22:43:48 +00:00
Benjamin Kramer 1649774816 [Instrumentation] Remove unused include
It's also a layering violation.

llvm-svn: 335528
2018-06-25 21:43:09 +00:00
Alexander Richardson 85e200e934 Add Triple::isMIPS()/isMIPS32()/isMIPS64(). NFC
There are quite a few if statements that enumerate all these cases. It gets
even worse in our fork of LLVM where we also have a Triple::cheri (which
is mips64 + CHERI instructions) and we had to update all if statements that
check for Triple::mips64 to also handle Triple::cheri. This patch helps to
reduce our diff to upstream and should also make some checks more readable.

Reviewed By: atanasyan

Differential Revision: https://reviews.llvm.org/D48548

llvm-svn: 335493
2018-06-25 16:49:20 +00:00
Chandler Carruth aa5f4d2e23 Revert r335306 (and r335314) - the Call Graph Profile pass.
This is the first pass in the main pipeline to use the legacy PM's
ability to run function analyses "on demand". Unfortunately, it turns
out there are bugs in that somewhat-hacky approach. At the very least,
it leaks memory and doesn't support -debug-pass=Structure. Unclear if
there are larger issues or not, but this should get the sanitizer bots
back to green by fixing the memory leaks.

llvm-svn: 335320
2018-06-22 05:33:57 +00:00
Michael J. Spencer fc93dd8e18 [Instrumentation] Add Call Graph Profile pass
This patch adds support for generating a call graph profile from Branch Frequency Info.

The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions. For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.

After scanning all the functions, it generates an appending module flag containing the data. The format looks like:

!llvm.module.flags = !{!0}

!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}

Differential Revision: https://reviews.llvm.org/D48105

llvm-svn: 335306
2018-06-21 23:31:10 +00:00
Matt Morehouse 0ea9a90b3d [SanitizerCoverage] Add associated metadata to pc-tables.
Summary:
Using associated metadata rather than llvm.used allows linkers to
perform dead stripping with -fsanitize-coverage=pc-table.  Unfortunately
in my local tests, LLD was the only linker that made use of this metadata.

Partially addresses https://bugs.llvm.org/show_bug.cgi?id=34636 and fixes
https://github.com/google/sanitizers/issues/971.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: Dor1s, hiraditya, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D48203

llvm-svn: 334858
2018-06-15 20:12:58 +00:00
Reid Kleckner 12395b7795 [WinASan] Don't instrument globals in sections containing '$'
Such globals are very likely to be part of a sorted section array, such
the .CRT sections used for dynamic initialization. The uses its own
sorted sections called ATL$__a, ATL$__m, and ATL$__z. Instead of special
casing them, just look for the dollar sign, which is what invokes linker
section sorting for COFF.

Avoids issues with ASan and the ATL uncovered after we started
instrumenting comdat globals on COFF.

llvm-svn: 334653
2018-06-13 20:47:21 +00:00
Florian Hahn a1cc848399 Use SmallPtrSet explicitly for SmallSets with pointer types (NFC).
Currently SmallSet<PointerTy> inherits from SmallPtrSet<PointerTy>. This
patch replaces such types with SmallPtrSet, because IMO it is slightly
clearer and allows us to get rid of unnecessarily including SmallSet.h

Reviewers: dblaikie, craig.topper

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D47836

llvm-svn: 334492
2018-06-12 11:16:56 +00:00
Reid Kleckner 0bab222084 [asan] Instrument comdat globals on COFF targets
Summary:
If we can use comdats, then we can make it so that the global metadata
is thrown away if the prevailing definition of the global was
uninstrumented. I have only tested this on COFF targets, but in theory,
there is no reason that we cannot also do this for ELF.

This will allow us to re-enable string merging with ASan on Windows,
reducing the binary size cost of ASan on Windows.

Reviewers: eugenis, vitalybuka

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D47841

llvm-svn: 334313
2018-06-08 18:33:16 +00:00
David Blaikie 31b98d2e99 Move Analysis/Utils/Local.h back to Transforms
Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)

llvm-svn: 333954
2018-06-04 21:23:21 +00:00
Evgeniy Stepanov 28f330fd6f [msan] Don't check divisor shadow in fdiv.
Summary:
Floating point division by zero or even undef does not have undefined
behavior and may occur due to optimizations.

Fixes https://bugs.llvm.org/show_bug.cgi?id=37523.

Reviewers: kcc

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D47085

llvm-svn: 332761
2018-05-18 20:19:53 +00:00
Walter Lee cdbb207bd1 [asan] Add instrumentation support for Myriad
1. Define Myriad-specific ASan constants.

2. Add code to generate an outer loop that checks that the address is
   in DRAM range, and strip the cache bit from the address.  The
   former is required because Myriad has no memory protection, and it
   is up to the instrumentation to range-check before using it to
   index into the shadow memory.

3. Do not add an unreachable instruction after the error reporting
   function; on Myriad such function may return if the run-time has
   not been initialized.

4. Add a test.

Differential Revision: https://reviews.llvm.org/D46451

llvm-svn: 332692
2018-05-18 04:10:38 +00:00
Heejin Ahn b4be38fcdd [WebAssembly] Add Wasm personality and isScopedEHPersonality()
Summary:
- Add wasm personality function
- Re-categorize the existing `isFuncletEHPersonality()` function into
two different functions: `isFuncletEHPersonality()` and
`isScopedEHPersonality(). This becomes necessary as wasm EH uses scoped
EH instructions (catchswitch, catchpad/ret, and cleanuppad/ret) but not
outlined funclets.
- Changed some callsites of `isFuncletEHPersonality()` to
`isScopedEHPersonality()` if they are related to scoped EH IR-level
stuff.

Reviewers: majnemer, dschuff, rnk

Subscribers: jfb, sbc100, jgravelle-google, eraman, JDevlieghere, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D45559

llvm-svn: 332667
2018-05-17 20:52:03 +00:00
Evgeniy Stepanov 091fed94ae [msan] Instrument masked.store, masked.load intrinsics.
Summary: Instrument masked store/load intrinsics.

Reviewers: kcc

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D46785

llvm-svn: 332402
2018-05-15 21:28:25 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Craig Topper 0e71c6d5ca [X86] Remove and autoupgrade the cvtusi2sd intrinsic. Use uitofp+insertelement instead.
llvm-svn: 332206
2018-05-14 00:06:49 +00:00
Craig Topper df3a9cedff [X86] Remove an autoupgrade legacy cvtss2sd intrinsics.
llvm-svn: 332187
2018-05-13 00:29:40 +00:00
Craig Topper 38ad7ddabc [X86] Remove and autoupgrade cvtsi2ss/cvtsi2sd intrinsics to match what clang has used for a very long time.
llvm-svn: 332186
2018-05-12 23:14:39 +00:00
Kostya Serebryany a2759327fd [sanitizer-coverage] don't instrument a function if it's entry block ends with 'unreachable'
llvm-svn: 332072
2018-05-11 01:09:39 +00:00
Kamil Rytarowski 02c432a72b Register NetBSD/i386 in AddressSanitizer.cpp
Summary:
Ship kNetBSD_ShadowOffset32 set to 1ULL << 30.

This is prepared for the amd64 kernel runtime.

Sponsored by <The NetBSD Foundation>

Reviewers: vitalybuka, joerg, kcc

Reviewed By: vitalybuka

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46724

llvm-svn: 332069
2018-05-11 00:58:01 +00:00
Chandler Carruth e74c354d12 [gcov] Switch to an explicit if clunky array to satisfy some compilers
on various build bots that are unhappy with using makeArrayRef with an
initializer list.

llvm-svn: 331418
2018-05-03 00:11:03 +00:00
Chandler Carruth 71c3a3fac5 [GCOV] Emit the writeout function as nested loops of global data.
Summary:
Prior to this change, LLVM would in some cases emit *massive* writeout
functions with many 10s of 1000s of function calls in straight-line
code. This is a very wasteful way to represent what are fundamentally
loops and creates a number of scalability issues. Among other things,
register allocating these calls is extremely expensive. While D46127 makes this
less severe, we'll still run into scaling issues with this eventually. If not
in the compile time, just from the code size.

Now the pass builds up global data structures modeling the inputs to
these functions, and simply loops over the data structures calling the
relevant functions with those values. This ensures that the code size is
a fixed and only data size grows with larger amounts of coverage data.

A trivial change to IRBuilder is included to make it easier to build
the constants that make up the global data.

Reviewers: wmi, echristo

Subscribers: sanjoy, mcrosier, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D46357

llvm-svn: 331407
2018-05-02 22:24:39 +00:00