[Support] Make report_fatal_error respect its GenCrashDiag argument so it doesn't generate a backtrace

There are a few places where we use report_fatal_error when the input is broken.
Currently, thi

[Support] Make report_fatal_error respect its GenCrashDiag argument so it doesn't generate a backtrace

There are a few places where we use report_fatal_error when the input is broken.
Currently, this function always crashes LLVM with an abort signal, which
then triggers the backtrace printing code.
I think this is excessive, as wrong input shouldn't give a link to
LLVM's github issue URL and tell users to file a bug report.
We shouldn't print a stack trace either.

This patch changes report_fatal_error so it uses exit() rather than
abort() when its argument GenCrashDiag=false.

Reviewed by: nikic, MaskRay, RKSimon

Differential Revision: https://reviews.llvm.org/D126550

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[iwyu] Handle regressions in libLLVM header include

Running iwyu-diff on LLVM codebase since fa5a4e1b95c8f37796 detected a few
regressions, fixing them.

Differential Revision: https://reviews.llvm.

[iwyu] Handle regressions in libLLVM header include

Running iwyu-diff on LLVM codebase since fa5a4e1b95c8f37796 detected a few
regressions, fixing them.

Differential Revision: https://reviews.llvm.org/D124847

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[LegacyPM] Remove GCOVProfilerLegacyPass

Using the legacy PM for the optimization pipeline was deprecated in 13.0.0.
Following recent changes to remove non-core features of the legacy
PM/optimizatio

[LegacyPM] Remove GCOVProfilerLegacyPass

Using the legacy PM for the optimization pipeline was deprecated in 13.0.0.
Following recent changes to remove non-core features of the legacy
PM/optimization pipeline, remove GCOVProfilerLegacyPass.

I have checked many LLVM users and only llvm-hs[1] uses the legacy gcov pass.

[1]: https://github.com/llvm-hs/llvm-hs/issues/392

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D123829

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Cleanup includes: DebugInfo & CodeGen

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121332

PGOInstrumentation, GCOVProfiling: Split indirectbr critical edges regardless of PHIs

The `SplitIndirectBrCriticalEdges` function was originally designed for
`CodeGenPrepare` and skipped splitting o

PGOInstrumentation, GCOVProfiling: Split indirectbr critical edges regardless of PHIs

The `SplitIndirectBrCriticalEdges` function was originally designed for
`CodeGenPrepare` and skipped splitting of edges when the destination
block didn't contain any `PHI` instructions. This only makes sense when
reducing COPYs like `CodeGenPrepare`. In the case of
`PGOInstrumentation` or `GCOVProfiling` it would result in missed
counters and wrong result in functions with computed goto.

Differential Revision: https://reviews.llvm.org/D120096

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[llvm] Replace report_fatal_error(std::string) uses with report_fatal_error(Twine)

As described on D111049, we're trying to remove the <string> dependency from error handling and replace uses of rep

[llvm] Replace report_fatal_error(std::string) uses with report_fatal_error(Twine)

As described on D111049, we're trying to remove the <string> dependency from error handling and replace uses of report_fatal_error(const std::string&) with the Twine() variant which can be forward declared.

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[GCov] Emit memset instead of stores in __llvm_gcov_reset

For a very large module, __llvm_gcov_reset can become very large.
__llvm_gcov_reset previously emitted stores to a bunch of globals in one
h

[GCov] Emit memset instead of stores in __llvm_gcov_reset

For a very large module, __llvm_gcov_reset can become very large.
__llvm_gcov_reset previously emitted stores to a bunch of globals in one
huge basic block. MemCpyOpt would turn many of these stores into
memsets, and updating MemorySSA would be extremely slow.

Verified that this makes the compile time of certain files go down
drastically (20min -> 5min).

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D107538

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[GCOVProfiling] don't profile Fn's w/ noprofile attribute

Similar to D104475, the Linux kernel would like to avoid compiler
generated code in certain functions. The no_profile function
attribute can

[GCOVProfiling] don't profile Fn's w/ noprofile attribute

Similar to D104475, the Linux kernel would like to avoid compiler
generated code in certain functions. The no_profile function
attribute can be used in C to generate the the noprofile fn attr in IR.
Respect that from GCOVProfiling.

Link: https://lore.kernel.org/lkml/CAKwvOdmPTi93n2L0_yQkrzLdmpxzrOR7zggSzonyaw2PGshApw@mail.gmail.com/

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D104257

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[gcov] Set nounwind and respect module flags metadata "frame-pointer" & "uwtable" for synthesized functions

This applies the D100251 mechanism to the gcov instrumentation pass.

With this patch, `-f

[gcov] Set nounwind and respect module flags metadata "frame-pointer" & "uwtable" for synthesized functions

This applies the D100251 mechanism to the gcov instrumentation pass.

With this patch, `-fno-omit-frame-pointer` in
`clang -fprofile-arcs -O1 -fno-omit-frame-pointer` will be respected for synthesized
`__llvm_gcov_writeout,__llvm_gcov_reset,__llvm_gcov_init` functions: the frame pointer
will be kept (note: on many targets -O1 eliminates the frame pointer by default).

`clang -fno-exceptions -fno-asynchronous-unwind-tables -g -fprofile-arcs` will
produce .debug_frame instead of .eh_frame.

Fix: https://github.com/ClangBuiltLinux/linux/issues/955

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D101129

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Add Alignment argument to IRBuilder CreateAtomicRMW and CreateAtomicCmpXchg.

And then push those change throughout LLVM.

Keep the old signature in Clang's CGBuilder for now -- that will be
updated

Add Alignment argument to IRBuilder CreateAtomicRMW and CreateAtomicCmpXchg.

And then push those change throughout LLVM.

Keep the old signature in Clang's CGBuilder for now -- that will be
updated in a follow-on patch (D97224).

The MLIR LLVM-IR dialect is not updated to support the new alignment
attribute, but preserves its existing behavior.

Differential Revision: https://reviews.llvm.org/D97223

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[GCOV] Drop unnecessary const from return types (NFC)

Identified with readability-const-return-type.

[NFC][GCOV] Fix build: there's `llvm::stable_partition()` wrapper

[gcov] Fix non-determinism (DenseMap iteration order) of checksum computation

... by using MapVector. The issue was caused by 63182c2ac0b643a60d397274e8a31166fc7243fa.

Also use stable_partition ins

[gcov] Fix non-determinism (DenseMap iteration order) of checksum computation

... by using MapVector. The issue was caused by 63182c2ac0b643a60d397274e8a31166fc7243fa.

Also use stable_partition instead of partition to get stable results
across different STL implementations.

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GCOVProfiling: Avoid use-after-move

Turns out this was use-after-move of function_ref, which is trivially
copyable and movable, so the move did nothing and use after move was
safe.

But since this f

GCOVProfiling: Avoid use-after-move

Turns out this was use-after-move of function_ref, which is trivially
copyable and movable, so the move did nothing and use after move was
safe.

But since this function_ref is being copied into a std::function, change
the function_ref to be std::function to avoid extra layers of type
erasure indirection - and then it's a real use after move, and fix that
by referring to the moved-to member variable rather than the moved-from
parameter.

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[gcov] Fix memory leak due to BranchProbabilityInfoWrapperPass

This is weird.

[gcov] Add spanning tree optimization

gcov is an "Edge Profiling with Edge Counters" application according to
Optimally Profiling and Tracing Programs (1994).

The minimum number of counters necessa

[gcov] Add spanning tree optimization

gcov is an "Edge Profiling with Edge Counters" application according to
Optimally Profiling and Tracing Programs (1994).

The minimum number of counters necessary is |E|-(|V|-1). The unmeasured edges
form a spanning tree. Both GCC --coverage and clang -fprofile-generate leverage
this optimization. This patch implements the optimization for clang --coverage.
The produced .gcda files are much smaller now.

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[gcov] Assign names to some types and loaded values used in @__llvm_internal*

This makes the generated IR much more readable.

[gcov] Process .gcda immediately after the accompanying .gcno instead of doing all .gcda after all .gcno

i.e. change the work flow from

* .gcno for function A
* .gcno for function B
* .gcno for fun

[gcov] Process .gcda immediately after the accompanying .gcno instead of doing all .gcda after all .gcno

i.e. change the work flow from

* .gcno for function A
* .gcno for function B
* .gcno for function C
* .gcda for function A
* .gcda for function B
* .gcda for function C

to

* .gcno for function A
* .gcda for function A
* .gcno for function B
* .gcda for function B
* .gcno for function C
* .gcda for function C

Currently there is duplicate logic in .gcno & .gcda processing: how functions
are filtered, which edges are instrumented, etc. This refactor enables simplification.

Since we always process .gcno, in -fprofile-arcs -fno-test-coverage mode,
__llvm_internal_gcov_emit_function_args.0 will have non-zero checksums.

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Revert "[gcov] emitProfileArcs: iterate over GCOVFunction's instead of Function's to avoid duplicated filtering"

This reverts commit 412c9c0bf2a8ccbda2d925575891a51ef5df846e.

[gcov] emitProfileArcs: iterate over GCOVFunction's instead of Function's to avoid duplicated filtering

[gcov] Clean up by getting llvm.dbg.cu earlier

[gcov] Give the __llvm_gcov_ctr load instruction a name for more readable output

[gcov] Don't split entry block; add a synthetic entry block instead

The entry block is split at the first instruction where `shouldKeepInEntry`
returns false. The created basic block has a br jumpin

[gcov] Don't split entry block; add a synthetic entry block instead

The entry block is split at the first instruction where `shouldKeepInEntry`
returns false. The created basic block has a br jumping to the original entry
block. The new basic block causes the function label line and the other entry
block lines to be covered by different basic blocks, which can affect line
counts with special control flows (fork/exec in the entry block requires
heuristics in llvm-cov gcov to get consistent line counts).

int main() { // BB0
return 0; // BB2 (due to entry block splitting)
}
// BB1 is the exit block (since gcov 4.8)

This patch adds a synthetic entry block (like PGOInstrumentation and GCC) and
inserts an edge from the synthetic entry block to the original entry block. We
can thus remove the tricky `shouldKeepInEntry` and entry block splitting. The
number of basic blocks does not change, but the emitted .gcno files will be
smaller because we can save one GCOV_TAG_LINES tag.

// BB0 is the synthetic entry block with a single edge to BB2
int main() { // BB2
return 0; // BB2
}
// BB1 is the exit block (since gcov 4.8)

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[gcov] Increment counters with atomicrmw if -fsanitize=thread

Without this patch, `clang --coverage -fsanitize=thread` may fail spuriously
because non-atomic counter increments can be detected as da

[gcov] Increment counters with atomicrmw if -fsanitize=thread

Without this patch, `clang --coverage -fsanitize=thread` may fail spuriously
because non-atomic counter increments can be detected as data races.

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[gcov] Simplify/speed up CFG hash calculation