This lets us to remove !stack-safe metadata and
better controll when to perform StackSafety
analysis.
Reviewers: eugenis
Subscribers: hiraditya, steven_wu, dexonsmith, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D80771
This patch adds clang options:
-fbasic-block-sections={all,<filename>,labels,none} and
-funique-basic-block-section-names.
LLVM Support for basic block sections is already enabled.
+ -fbasic-block-sections={all, <file>, labels, none} : Enables/Disables basic
block sections for all or a subset of basic blocks. "labels" only enables
basic block symbols.
+ -funique-basic-block-section-names: Enables unique section names for
basic block sections, disabled by default.
Differential Revision: https://reviews.llvm.org/D68049
Canonicalize on storing FP options in LangOptions instead of
redundantly in CodeGenOptions. Incorporate -ffast-math directly
into the values of those LangOptions rather than considering it
separately when building FPOptions. Build IR attributes from
those options rather than a mix of sources.
We should really simplify the driver/cc1 interaction here and have
the driver pass down options that cc1 directly honors. That can
happen in a follow-up, though.
Patch by Michele Scandale!
https://reviews.llvm.org/D80315
Summary:
This was attempted once before in https://reviews.llvm.org/D79698, but
was reverted due to the coverage pass running in the wrong part of the
pipeline. This commit puts it in the same place as the other sanitizers.
This changes PassBuilder.OptimizerLastEPCallbacks to work on a
ModulePassManager instead of a FunctionPassManager. That is because
SanitizerCoverage cannot (easily) be split into a module pass and a
function pass like some of the other sanitizers since in its current
implementation it conditionally inserts module constructors based on
whether or not it successfully modified functions.
This fixes compiler-rt/test/msan/coverage-levels.cpp under the new pass
manager (last check-msan test).
Currently sanitizers + LTO don't work together under the new pass
manager, so I removed tests that checked that this combination works for
sancov.
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D80692
Summary:
This was attempted once before in https://reviews.llvm.org/D79698, but
was reverted due to the coverage pass running in the wrong part of the
pipeline. This commit puts it in the same place as the other sanitizers.
This changes PassBuilder.OptimizerLastEPCallbacks to work on a
ModulePassManager instead of a FunctionPassManager. That is because
SanitizerCoverage cannot (easily) be split into a module pass and a
function pass like some of the other sanitizers since in its current
implementation it conditionally inserts module constructors based on
whether or not it successfully modified functions.
This fixes compiler-rt/test/msan/coverage-levels.cpp under the new pass
manager (last check-msan test).
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D80692
This reverts commit 7d5bb94d78386e4653535c35d3e8258bf4502340.
Reverting since this leads to a linker error we're seeing on Fuchsia.
The underlying issue seems to be that inlining is run after sanitizers
and causes different comdat groups instrumented by Sancov to reference
non-key symbols defined in other comdat groups.
Will re-land this patch after a fix for that is landed.
gcov 4.8 (r189778) moved the exit block from the last to the second.
The .gcda format is compatible with 4.7 but
* decoding libgcov 4.7 produced .gcda with gcov [4.7,8) can mistake the
exit block, emit bogus `%s:'%s' has arcs from exit block\n` warnings,
and print wrong `" returned %s` for branch statistics (-b).
* decoding libgcov 4.8 produced .gcda with gcov 4.7 has similar issues.
Also, rename "return block" to "exit block" because the latter is the
appropriate term.
Summary:
This fixes compiler-rt/test/msan/coverage-levels.cpp under the new pass manager (final check-msan test!).
Under the old pass manager, the coverage pass would run before the MSan pass. The opposite happened under the new pass manager. The MSan pass adds extra basic blocks, changing the number of coverage callbacks.
Reviewers: vitalybuka, leonardchan
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D79698
Defaulting to -Xclang -coverage-version='407*' makes .gcno/.gcda
compatible with gcov [4.7,8)
In addition, delete clang::CodeGenOptionsBase::CoverageExtraChecksum and GCOVOptions::UseCfgChecksum.
We can infer the information from the version.
With this change, .gcda files produced by `clang --coverage a.o` linked executable can be read by gcov 4.7~7.
We don't need other -Xclang -coverage* options.
There may be a mismatching version warning, though.
(Note, GCC r173147 "split checksum into cfg checksum and line checksum"
made gcov 4.7 incompatible with previous versions.)
rL144865 incorrectly wrote function names for GCOV_TAG_FUNCTION
(this might be part of the reasons the header says
"We emit files in a corrupt version of GCOV's "gcda" file format").
rL176173 and rL177475 realized the problem and introduced -coverage-no-function-names-in-data
to work around the issue. (However, the description is wrong.
libgcov never writes function names, even before GCC 4.2).
In reality, the linker command line has to look like:
clang --coverage -Xclang -coverage-version='407*' -Xclang -coverage-cfg-checksum -Xclang -coverage-no-function-names-in-data
Failing to pass -coverage-no-function-names-in-data can make gcov 4.7~7
either produce wrong results (for one gcov-4.9 program, I see "No executable lines")
or segfault (gcov-7).
(gcov-8 uses an incompatible format.)
This patch deletes -coverage-no-function-names-in-data and the related
function names support from libclang_rt.profile
https://reviews.llvm.org/D63616 added `-fsanitize-coverage-whitelist`
and `-fsanitize-coverage-blacklist` for clang.
However, it was done only for legacy pass manager.
This patch enable it for new pass manager as well.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D79653
This is a standalone patch and this would help Propeller do a better job of code
layout as it can accurately attribute the profiles to the right internal linkage
function.
This also helps SampledFDO/AutoFDO correctly associate sampled profiles to the
right internal function. Currently, if there is more than one internal symbol
foo, their profiles are aggregated by SampledFDO.
This patch adds a new clang option, -funique-internal-funcnames, to generate
unique names for functions with internal linkage. This patch appends the md5
hash of the module name to the function symbol as a best effort to generate a
unique name for symbols with internal linkage.
Differential Revision: https://reviews.llvm.org/D73307
Summary:
Properly forward TrackOrigins and Recover user options to the MSan pass under the new pass manager.
This makes the number of check-msan failures when ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER is TRUE go from 52 to 2.
Based on https://reviews.llvm.org/D77249.
Reviewers: nemanjai, vitalybuka, leonardchan
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D79445
This reverts commit 60c642e74be6af86906d9f3d982728be7bd4329f.
This patch is making the TLI "closed" for a predefined set of VecLib
while at the moment it is extensible for anyone to customize when using
LLVM as a library.
Reverting while we figure out a way to re-land it without losing the
generality of the current API.
Differential Revision: https://reviews.llvm.org/D77925
Summary:
This commit adds two command-line options to clang.
These options let the user decide which functions will receive SanitizerCoverage instrumentation.
This is most useful in the libFuzzer use case, where it enables targeted coverage-guided fuzzing.
Patch by Yannis Juglaret of DGA-MI, Rennes, France
libFuzzer tests its target against an evolving corpus, and relies on SanitizerCoverage instrumentation to collect the code coverage information that drives corpus evolution. Currently, libFuzzer collects such information for all functions of the target under test, and adds to the corpus every mutated sample that finds a new code coverage path in any function of the target. We propose instead to let the user specify which functions' code coverage information is relevant for building the upcoming fuzzing campaign's corpus. To this end, we add two new command line options for clang, enabling targeted coverage-guided fuzzing with libFuzzer. We see targeted coverage guided fuzzing as a simple way to leverage libFuzzer for big targets with thousands of functions or multiple dependencies. We publish this patch as work from DGA-MI of Rennes, France, with proper authorization from the hierarchy.
Targeted coverage-guided fuzzing can accelerate bug finding for two reasons. First, the compiler will avoid costly instrumentation for non-relevant functions, accelerating fuzzer execution for each call to any of these functions. Second, the built fuzzer will produce and use a more accurate corpus, because it will not keep the samples that find new coverage paths in non-relevant functions.
The two new command line options are `-fsanitize-coverage-whitelist` and `-fsanitize-coverage-blacklist`. They accept files in the same format as the existing `-fsanitize-blacklist` option <https://clang.llvm.org/docs/SanitizerSpecialCaseList.html#format>. The new options influence SanitizerCoverage so that it will only instrument a subset of the functions in the target. We explain these options in detail in `clang/docs/SanitizerCoverage.rst`.
Consider now the woff2 fuzzing example from the libFuzzer tutorial <https://github.com/google/fuzzer-test-suite/blob/master/tutorial/libFuzzerTutorial.md>. We are aware that we cannot conclude much from this example because mutating compressed data is generally a bad idea, but let us use it anyway as an illustration for its simplicity. Let us use an empty blacklist together with one of the three following whitelists:
```
# (a)
src:*
fun:*
# (b)
src:SRC/*
fun:*
# (c)
src:SRC/src/woff2_dec.cc
fun:*
```
Running the built fuzzers shows how many instrumentation points the compiler adds, the fuzzer will output //XXX PCs//. Whitelist (a) is the instrument-everything whitelist, it produces 11912 instrumentation points. Whitelist (b) focuses coverage to instrument woff2 source code only, ignoring the dependency code for brotli (de)compression; it produces 3984 instrumented instrumentation points. Whitelist (c) focuses coverage to only instrument functions in the main file that deals with WOFF2 to TTF conversion, resulting in 1056 instrumentation points.
For experimentation purposes, we ran each fuzzer approximately 100 times, single process, with the initial corpus provided in the tutorial. We let the fuzzer run until it either found the heap buffer overflow or went out of memory. On this simple example, whitelists (b) and (c) found the heap buffer overflow more reliably and 5x faster than whitelist (a). The average execution times when finding the heap buffer overflow were as follows: (a) 904 s, (b) 156 s, and (c) 176 s.
We explain these results by the fact that WOFF2 to TTF conversion calls the brotli decompression algorithm's functions, which are mostly irrelevant for finding bugs in WOFF2 font reconstruction but nevertheless instrumented and used by whitelist (a) to guide fuzzing. This results in longer execution time for these functions and a partially irrelevant corpus. Contrary to whitelist (a), whitelists (b) and (c) will execute brotli-related functions without instrumentation overhead, and ignore new code paths found in them. This results in faster bug finding for WOFF2 font reconstruction.
The results for whitelist (b) are similar to the ones for whitelist (c). Indeed, WOFF2 to TTF conversion calls functions that are mostly located in SRC/src/woff2_dec.cc. The 2892 extra instrumentation points allowed by whitelist (b) do not tamper with bug finding, even though they are mostly irrelevant, simply because most of these functions do not get called. We get a slightly faster average time for bug finding with whitelist (b), which might indicate that some of the extra instrumentation points are actually relevant, or might just be random noise.
Reviewers: kcc, morehouse, vitalybuka
Reviewed By: morehouse, vitalybuka
Subscribers: pratyai, vitalybuka, eternalsakura, xwlin222, dende, srhines, kubamracek, #sanitizers, lebedev.ri, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D63616
Summary:
Encode `-fveclib` setting as per-function attribute so it can threaded through to LTO backends. Accordingly per-function TLI now reads
the attributes and select available vector function list based on that. Now we also populate function list for all supported vector
libraries for the shared per-module `TargetLibraryInfoImpl`, so each function can select its available vector list independently but without
duplicating the vector function lists. Inlining between incompatbile vectlib attributed is also prohibited now.
Subscribers: hiraditya, dexonsmith, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D77632
Summary:
CGProfilePass is run by default in certain new pass manager optimization pipeline. Assemblers other than llvm as (such as gnu as) cannot recognize the .cgprofile entries generated and emitted from this pass, causing build time error.
This patch adds new options in clang CodeGenOpts and PassBuilder options so that we can turn cgprofile off when not using integrated assembler.
Reviewers: Bigcheese, xur, george.burgess.iv, chandlerc, manojgupta
Reviewed By: manojgupta
Subscribers: manojgupta, void, hiraditya, dexonsmith, llvm-commits, tcwang, llozano
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D62627
Summary:
Run StackSafetyAnalysis at the end of the IR pipeline and annotate
proven safe allocas with !stack-safe metadata. Do not instrument such
allocas in the AArch64StackTagging pass.
Reviewers: pcc, vitalybuka, ostannard
Reviewed By: vitalybuka
Subscribers: merge_guards_bot, kristof.beyls, hiraditya, cfe-commits, gilang, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73513
Summary:
Depends on https://reviews.llvm.org/D71902.
The last in a series of six patches that ports the LLVM coroutines
passes to the new pass manager infrastructure.
This patch has Clang schedule the new coroutines passes when the
`-fexperimental-new-pass-manager` option is used. With this and the
previous 5 patches, Clang is capable of building and successfully
running the test suite of large coroutines projects such as
https://github.com/lewissbaker/cppcoro with
`ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER=On`.
Reviewers: GorNishanov, lewissbaker, chandlerc, junparser
Subscribers: EricWF, cfe-commits, llvm-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D71903
This patch enables the debug entry values feature.
- Remove the (CC1) experimental -femit-debug-entry-values option
- Enable it for x86, arm and aarch64 targets
- Resolve the test failures
- Leave the llc experimental option for targets that do not
support the CallSiteInfo yet
Differential Revision: https://reviews.llvm.org/D73534
This patch enables the debug entry values feature.
- Remove the (CC1) experimental -femit-debug-entry-values option
- Enable it for x86, arm and aarch64 targets
- Resolve the test failures
- Leave the llc experimental option for targets that do not
support the CallSiteInfo yet
Differential Revision: https://reviews.llvm.org/D73534
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
This restores 59733525d37cf9ad88b5021b33ecdbaf2e18911c (D71913), along
with bot fix 19c76989bb505c3117730c47df85fd3800ea2767.
The bot failure should be fixed by D73418, committed as
af954e441a5170a75687699d91d85e0692929d43.
I also added a fix for non-x86 bot failures by requiring x86 in new test
lld/test/ELF/lto/devirt_vcall_vis_public.ll.
Summary:
Third part in series to support Safe Whole Program Devirtualization
Enablement, see RFC here:
http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html
This patch adds type test metadata under -fwhole-program-vtables,
even for classes without hidden visibility. It then changes WPD to skip
devirtualization for a virtual function call when any of the compatible
vtables has public vcall visibility.
Additionally, internal LLVM options as well as lld and gold-plugin
options are added which enable upgrading all public vcall visibility
to linkage unit (hidden) visibility during LTO. This enables the more
aggressive WPD to kick in based on LTO time knowledge of the visibility
guarantees.
Support was added to all flavors of LTO WPD (regular, hybrid and
index-only), and to both the new and old LTO APIs.
Unfortunately it was not simple to split the first and second parts of
this part of the change (the unconditional emission of type tests and
the upgrading of the vcall visiblity) as I needed a way to upgrade the
public visibility on legacy WPD llvm assembly tests that don't include
linkage unit vcall visibility specifiers, to avoid a lot of test churn.
I also added a mechanism to LowerTypeTests that allows dropping type
test assume sequences we now aggressively insert when we invoke
distributed ThinLTO backends with null indexes, which is used in testing
mode, and which doesn't invoke the normal ThinLTO backend pipeline.
Depends on D71907 and D71911.
Reviewers: pcc, evgeny777, steven_wu, espindola
Subscribers: emaste, Prazek, inglorion, arichardson, hiraditya, MaskRay, dexonsmith, dang, davidxl, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71913
Summary:
The old pass manager separated speed optimization and size optimization
levels into two unsigned values. Coallescing both in an enum in the new
pass manager may lead to unintentional casts and comparisons.
In particular, taking a look at how the loop unroll passes were constructed
previously, the Os/Oz are now (==new pass manager) treated just like O3,
likely unintentionally.
This change disallows raw comparisons between optimization levels, to
avoid such unintended effects. As an effect, the O{s|z} behavior changes
for loop unrolling and loop unroll and jam, matching O2 rather than O3.
The change also parameterizes the threshold values used for loop
unrolling, primarily to aid testing.
Reviewers: tejohnson, davidxl
Reviewed By: tejohnson
Subscribers: zzheng, ychen, mehdi_amini, hiraditya, steven_wu, dexonsmith, dang, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D72547
which is the default TLS model for non-PIC objects. This allows large/
many thread local variables or a compact/fast code in an executable.
Specification is same as that of GCC. For example, the code model
option precedes the TLS size option.
TLS access models other than local-exec are not changed. It means
supoort of the large code model is only in the local exec TLS model.
Patch By KAWASHIMA Takahiro (kawashima-fj <t-kawashima@fujitsu.com>)
Reviewers: dmgreen, mstorsjo, t.p.northover, peter.smith, ostannard
Reviewd By: peter.smith
Committed by: peter.smith
Differential Revision: https://reviews.llvm.org/D71688
down to pass builder in ltobackend.
Currently CodeGenOpts like UnrollLoops/VectorizeLoop/VectorizeSLP in clang
are not passed down to pass builder in ltobackend when new pass manager is
used. This is inconsistent with the behavior when new pass manager is used
and thinlto is not used. Such inconsistency causes slp vectorization pass
not being enabled in ltobackend for O3 + thinlto right now. This patch
fixes that.
Differential Revision: https://reviews.llvm.org/D72386
There's quite a lot of references to Polly in the LLVM CMake codebase. However
the registration pattern used by Polly could be useful to other external
projects: thanks to that mechanism it would be possible to develop LLVM
extension without touching the LLVM code base.
This patch has two effects:
1. Remove all code specific to Polly in the llvm/clang codebase, replaicing it
with a generic mechanism
2. Provide a generic mechanism to register compiler extensions.
A compiler extension is similar to a pass plugin, with the notable difference
that the compiler extension can be configured to be built dynamically (like
plugins) or statically (like regular passes).
As a result, people willing to add extra passes to clang/opt can do it using a
separate code repo, but still have their pass be linked in clang/opt as built-in
passes.
Differential Revision: https://reviews.llvm.org/D61446
clang/lib/CodeGen/CodeGenModule performs the -mpie-copy-relocations
check and sets dso_local on applicable global variables. We don't need
to duplicate the work in TargetMachine shouldAssumeDSOLocal.
Verified that -mpie-copy-relocations can still emit PC relative
relocations for external variable accesses.
clang -target x86_64 -fpie -mpie-copy-relocations -c => R_X86_64_PC32
clang -target aarch64 -fpie -mpie-copy-relocations -c => R_AARCH64_ADR_PREL_PG_HI21+R_AARCH64_LDST64_ABS_LO12_NC
Summary:
Follow-on to D66428 and D71193, to build the TLI per-function so
that -fno-builtin* handling can be migrated to use function attributes.
See discussion on D61634 for background. This is an enabler for fixing
handling of these options for LTO, for example.
With D71193, the -fno-builtin* flags are converted to function
attributes, so we can now set this information per-function on the TLI.
In this patch, the TLI constructor is changed to take a Function, which
can be used to override the available builtins. The TLI is augmented
with an array that can be used to specify which builtins are not
available for the corresponding function. The available function checks
are changed to consult this override before checking the underlying
module level baseline TLII. New code is added to set this override
array based on the attributes.
I also removed the code that sets availability in the TLII in clang from
the options, which is no longer needed.
I removed a per-Triple caching of TLII objects in the analysis object,
as it is based on the Module's Triple which is the same for all
functions in any case. Is there a case where we would be compiling
multiple Modules with different Triples in one compilation?
Finally, I have changed the legacy analysis wrapper to create and use
the new PM analysis class (TargetLibraryAnalysis) in getTLI. This is
consistent with the behavior of getTTI for the legacy
TargetTransformInfo analysis. This change means that getTLI now creates
a new TLI on each call (although that should be very cheap as we cache
the module level TLII, and computing the per-function
attribute based availability should also be reasonably efficient).
I measured the compile time for a large C++ file with tens of thousands
of functions and as expected there was no increase.
Reviewers: chandlerc, hfinkel, gchatelet
Subscribers: mehdi_amini, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67923
Summary:
This adds support for embedding bitcode in a binary during LTO. The libLTO gains supports the `-lto-embed-bitcode` flag. The option allows users of the LTO library to embed a bitcode section. For example, LLD can pass the option via `ld.lld -mllvm=-lto-embed-bitcode`.
This feature allows doing something comparable to `clang -c -fembed-bitcode`, but on the (LTO) linker level. Having bitcode alongside native code has many use-cases. To give an example, the MacOS linker can create a `-bitcode_bundle` section containing bitcode. Also, having this feature built into LLVM is an alternative to 3rd party tools such as [[ https://github.com/travitch/whole-program-llvm | wllvm ]] or [[ https://github.com/SRI-CSL/gllvm | gllvm ]]. As with these tools, this feature simplifies creating "whole-program" llvm bitcode files, but in contrast to wllvm/gllvm it does not rely on a specific llvm frontend/driver.
Patch by Josef Eisl <josef.eisl@oracle.com>
Reviewers: #llvm, #clang, rsmith, pcc, alexshap, tejohnson
Reviewed By: tejohnson
Subscribers: tejohnson, mehdi_amini, inglorion, hiraditya, aheejin, steven_wu, dexonsmith, dang, cfe-commits, llvm-commits, #llvm, #clang
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D68213
This simplifies code where no extra details are required
Also don't write out detail when it is empty.
Differential Revision: https://reviews.llvm.org/D71347
Avoids the need to include TargetMachine.h from various places just for
an enum. Various other enums live here, such as the optimization level,
TLS model, etc. Data suggests that this change probably doesn't matter,
but it seems nice to have anyway.
This adds a flag to LLVM and clang to always generate a .debug_frame
section, even if other debug information is not being generated. In
situations where .eh_frame would normally be emitted, both .debug_frame
and .eh_frame will be used.
Differential Revision: https://reviews.llvm.org/D67216
