[Clang][CoverageMapping] Fix switch counter codegen compile time explosion

C++ generated code with huge amount of switch cases chokes badly while emitting
coverage mapping, in our specific testcase

[Clang][CoverageMapping] Fix switch counter codegen compile time explosion

C++ generated code with huge amount of switch cases chokes badly while emitting
coverage mapping, in our specific testcase (~72k cases), it won't stop after hours.
After this change, the frontend job now finishes in 4.5s and shrinks down `@__covrec_`
by 288k when compared to disabling simplification altogether.

There's probably no good way to create a testcase for this, but it's easy to
reproduce, just add thousands of cases in the below switch, and build with
`-fprofile-instr-generate -fcoverage-mapping`.

```
enum type : int {
FEATURE_INVALID = 0,
FEATURE_A = 1,
...
};

const char *to_string(type e) {
switch (e) {
case type::FEATURE_INVALID: return "FEATURE_INVALID";
case type::FEATURE_A: return "FEATURE_A";}
...
}

```

Differential Revision: https://reviews.llvm.org/D126345

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[llvm] Remove redundant member initialization (NFC)

Identified with readability-redundant-member-init.

Revert "[llvm] Remove redundant member initialization (NFC)"

This reverts commit fd4808887ee47f3ec8a030e9211169ef4fb094c3.

This patch causes gcc to issue a lot of warnings like:

warning: base cl

Revert "[llvm] Remove redundant member initialization (NFC)"

This reverts commit fd4808887ee47f3ec8a030e9211169ef4fb094c3.

This patch causes gcc to issue a lot of warnings like:

warning: base class ‘class llvm::MCParsedAsmOperand’ should be
explicitly initialized in the copy constructor [-Wextra]

show more ...

[llvm] Remove redundant member initialization (NFC)

Identified with readability-redundant-member-init.

Coverage: Fix iterated type for LineCoverageIterator

LineCoverageIterator is not providing access to a mutable object. Fix it
to iterate over `const LineCoverageStats` so that `operator->()`
compile

Coverage: Fix iterated type for LineCoverageIterator

LineCoverageIterator is not providing access to a mutable object. Fix it
to iterate over `const LineCoverageStats` so that `operator->()`
compiles again after 6b9b86db9dd974585a5c71cf2e5231d1e3385f7c.

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[CoverageMapping] Handle gaps in counter IDs for source-based coverage

For source-based coverage, the frontend sets the counter IDs and the
constraints of counter IDs is not defined. For e.g., the

[CoverageMapping] Handle gaps in counter IDs for source-based coverage

For source-based coverage, the frontend sets the counter IDs and the
constraints of counter IDs is not defined. For e.g., the Rust frontend
until recently had a reserved counter #0
(https://github.com/rust-lang/rust/pull/83774). Rust coverage
instrumentation also creates counters on edges in addition to basic
blocks. Some functions may have more counters than regions.

This breaks an assumption in CoverageMapping.cpp where the number of
counters in a function is assumed to be bounded by the number of
regions:
Counts.assign(Record.MappingRegions.size(), 0);

This assumption causes CounterMappingContext::evaluate() to fail since
there are not enough counter values created in the above call to
`Counts.assign`. Consequently, some uncovered functions are not
reported in coverage reports.

This change walks a Function's CoverageMappingRecord to find the maximum
counter ID, and uses it to initialize the counter array when instrprof
records are missing for a function in sparse profiles.

Differential Revision: https://reviews.llvm.org/D101780

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[Coverage] Support overriding compilation directory

When making compilation relocatable, for example in distributed
compilation scenarios, we want to set compilation dir to a relative
value like `.`

[Coverage] Support overriding compilation directory

When making compilation relocatable, for example in distributed
compilation scenarios, we want to set compilation dir to a relative
value like `.` but this presents a problem when generating reports
because if the file path is relative as well, for example `..`, you
may end up writing files outside of the output directory.

This change introduces a flag that allows overriding the compilation
directory that's stored inside the profile with a different value that
is absolute.

Differential Revision: https://reviews.llvm.org/D100232

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[Coverage] Load records immediately

The current implementation keeps buffers generated for each object file
until it completes loading of all files. This approach requires a lot of memory
if there a

[Coverage] Load records immediately

The current implementation keeps buffers generated for each object file
until it completes loading of all files. This approach requires a lot of memory
if there are a lot of huge object files. Thus, make it to load coverage records
immediately rather than waiting for other binaries to be loaded.

This reduces memory usage of llvm-cov from >128GB to 5GB when
loading Chromium binaries in Windows.

Additional testing: check-profile, check-llvm

Differential Revision: https://reviews.llvm.org/D99110

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[Coverage] Store compilation dir separately in coverage mapping

We currently always store absolute filenames in coverage mapping. This
is problematic for several reasons. It poses a problem for dis

[Coverage] Store compilation dir separately in coverage mapping

We currently always store absolute filenames in coverage mapping. This
is problematic for several reasons. It poses a problem for distributed
compilation as source location might vary across machines. We are also
duplicating the path prefix potentially wasting space.

This change modifies how we store filenames in coverage mapping. Rather
than absolute paths, it stores the compilation directory and file paths
as given to the compiler, either relative or absolute. Later when
reading the coverage mapping information, we recombine relative paths
with the working directory. This approach is similar to handling
ofDW_AT_comp_dir in DWARF.

Finally, we also provide a new option, -fprofile-compilation-dir akin
to -fdebug-compilation-dir which can be used to manually override the
compilation directory which is useful in distributed compilation cases.

Differential Revision: https://reviews.llvm.org/D95753

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Revert "[Coverage] Store compilation dir separately in coverage mapping"

This reverts commit 97ec8fa5bb07e3f5bf25ddcb216b545cd3d03b65 since
the test is failing on some bots.

[Coverage] Store compilation dir separately in coverage mapping

We currently always store absolute filenames in coverage mapping. This
is problematic for several reasons. It poses a problem for dis

[Coverage] Store compilation dir separately in coverage mapping

We currently always store absolute filenames in coverage mapping. This
is problematic for several reasons. It poses a problem for distributed
compilation as source location might vary across machines. We are also
duplicating the path prefix potentially wasting space.

This change modifies how we store filenames in coverage mapping. Rather
than absolute paths, it stores the compilation directory and file paths
as given to the compiler, either relative or absolute. Later when
reading the coverage mapping information, we recombine relative paths
with the working directory. This approach is similar to handling
ofDW_AT_comp_dir in DWARF.

Finally, we also provide a new option, -fprofile-compilation-dir akin
to -fdebug-compilation-dir which can be used to manually override the
compilation directory which is useful in distributed compilation cases.

Differential Revision: https://reviews.llvm.org/D95753

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[Coverage] Add support for Branch Coverage in LLVM Source-Based Code Coverage

This is an enhancement to LLVM Source-Based Code Coverage in clang to track how
many times individual branch-generating

[Coverage] Add support for Branch Coverage in LLVM Source-Based Code Coverage

This is an enhancement to LLVM Source-Based Code Coverage in clang to track how
many times individual branch-generating conditions are taken (evaluate to TRUE)
and not taken (evaluate to FALSE). Individual conditions may comprise larger
boolean expressions using boolean logical operators. This functionality is
very similar to what is supported by GCOV except that it is very closely
anchored to the ASTs.

Differential Revision: https://reviews.llvm.org/D84467

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[llvm-cov] Warn when -arch spec is missing/invalid for universal binary (reland)

llvm-cov reports a poor error message when the -arch specifier is
missing or invalid, and a binary has multiple slice

[llvm-cov] Warn when -arch spec is missing/invalid for universal binary (reland)

llvm-cov reports a poor error message when the -arch specifier is
missing or invalid, and a binary has multiple slices. Make the error
message more specific.

(This version of the patch avoids using llvm::none_of -- the way I used
the utility caused compile errors on many bots, possibly because the
wrong overload of `none_of` was selected.)

rdar://40312677

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Revert "[llvm-cov] Warn when -arch spec is missing/invalid for universal binary"

This reverts commit b81d4bfb44c14575130bb06c047728b69c3213aa.

It's causing some bots to fail to build due to: "error

Revert "[llvm-cov] Warn when -arch spec is missing/invalid for universal binary"

This reverts commit b81d4bfb44c14575130bb06c047728b69c3213aa.

It's causing some bots to fail to build due to: "error: no matching
function for call to ‘__iterator_category".

show more ...

[llvm-cov] Warn when -arch spec is missing/invalid for universal binary

llvm-cov reports a poor error message when the -arch specifier is
missing or invalid, and a binary has multiple slices. Make t

[llvm-cov] Warn when -arch spec is missing/invalid for universal binary

llvm-cov reports a poor error message when the -arch specifier is
missing or invalid, and a binary has multiple slices. Make the error
message more specific.

rdar://40312677

show more ...

CoverageMapping.h - remove unused StringSet.h include. NFC.

Add cast to appease clang-armv7-linux-build-cache (D69471 followup)

http://lab.llvm.org:8011/builders/clang-armv7-linux-build-cache/builds/27075

error: non-constant-expression cannot be narrowed fr

Add cast to appease clang-armv7-linux-build-cache (D69471 followup)

http://lab.llvm.org:8011/builders/clang-armv7-linux-build-cache/builds/27075

error: non-constant-expression cannot be narrowed from type 'uint64_t'
(aka 'unsigned long long') to 'size_t' (aka 'unsigned int') in
initializer list [-Wc++11-narrowing]
return {MappingBuf, getDataSize<FuncRecordTy, Endian>(Record)};

show more ...

Reland: [Coverage] Revise format to reduce binary size

Try again with an up-to-date version of D69471 (99317124 was a stale
revision).

---

Revise the coverage mapping format to reduce binary size

Reland: [Coverage] Revise format to reduce binary size

Try again with an up-to-date version of D69471 (99317124 was a stale
revision).

---

Revise the coverage mapping format to reduce binary size by:

1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.

This shrinks the size of llc's coverage segment by 82% (334MB -> 62MB)
and speeds up end-to-end single-threaded report generation by 10%. For
reference the compressed name data in llc is 81MB (__llvm_prf_names).

Rationale for changes to the format:

- With the current format, most coverage function records are discarded.
E.g., more than 97% of the records in llc are *duplicate* placeholders
for functions visible-but-not-used in TUs. Placeholders *are* used to
show under-covered functions, but duplicate placeholders waste space.

- We reached general consensus about giving (1) a try at the 2017 code
coverage BoF [1]. The thinking was that using `linkonce_odr` to merge
duplicates is simpler than alternatives like teaching build systems
about a coverage-aware database/module/etc on the side.

- Revising the format is expensive due to the backwards compatibility
requirement, so we might as well compress filenames while we're at it.
This shrinks the encoded filenames in llc by 86% (12MB -> 1.6MB).

See CoverageMappingFormat.rst for the details on what exactly has
changed.

Fixes PR34533 [2], hopefully.

[1] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html
[2] https://bugs.llvm.org/show_bug.cgi?id=34533

Differential Revision: https://reviews.llvm.org/D69471

show more ...

Revert "[Coverage] Revise format to reduce binary size"

This reverts commit 99317124e1c772e9a9de41a0cd56e1db049b4ea4. This is
still busted on Windows:

http://lab.llvm.org:8011/builders/lld-x86_64-w

Revert "[Coverage] Revise format to reduce binary size"

This reverts commit 99317124e1c772e9a9de41a0cd56e1db049b4ea4. This is
still busted on Windows:

http://lab.llvm.org:8011/builders/lld-x86_64-win7/builds/40873

The llvm-cov tests report 'error: Could not load coverage information'.

show more ...

[Coverage] Revise format to reduce binary size

Revise the coverage mapping format to reduce binary size by:

1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.

[Coverage] Revise format to reduce binary size

Revise the coverage mapping format to reduce binary size by:

1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.

This shrinks the size of llc's coverage segment by 82% (334MB -> 62MB)
and speeds up end-to-end single-threaded report generation by 10%. For
reference the compressed name data in llc is 81MB (__llvm_prf_names).

Rationale for changes to the format:

- With the current format, most coverage function records are discarded.
E.g., more than 97% of the records in llc are *duplicate* placeholders
for functions visible-but-not-used in TUs. Placeholders *are* used to
show under-covered functions, but duplicate placeholders waste space.

- We reached general consensus about giving (1) a try at the 2017 code
coverage BoF [1]. The thinking was that using `linkonce_odr` to merge
duplicates is simpler than alternatives like teaching build systems
about a coverage-aware database/module/etc on the side.

- Revising the format is expensive due to the backwards compatibility
requirement, so we might as well compress filenames while we're at it.
This shrinks the encoded filenames in llc by 86% (12MB -> 1.6MB).

See CoverageMappingFormat.rst for the details on what exactly has
changed.

Fixes PR34533 [2], hopefully.

[1] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html
[2] https://bugs.llvm.org/show_bug.cgi?id=34533

Differential Revision: https://reviews.llvm.org/D69471

show more ...

Revert "[Coverage] Revise format to reduce binary size"

This reverts commit e18531595bba495946aa52c0a16b9f9238cff8bc.

On Windows, there is an error:

http://lab.llvm.org:8011/builders/sanitizer-win

Revert "[Coverage] Revise format to reduce binary size"

This reverts commit e18531595bba495946aa52c0a16b9f9238cff8bc.

On Windows, there is an error:

http://lab.llvm.org:8011/builders/sanitizer-windows/builds/54963/steps/stage%201%20check/logs/stdio

error: C:\b\slave\sanitizer-windows\build\stage1\projects\compiler-rt\test\profile\Profile-x86_64\Output\instrprof-merging.cpp.tmp.v1.o: Failed to load coverage: Malformed coverage data

show more ...

[Coverage] Revise format to reduce binary size

Revise the coverage mapping format to reduce binary size by:

1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.

[Coverage] Revise format to reduce binary size

Revise the coverage mapping format to reduce binary size by:

1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.

This shrinks the size of llc's coverage segment by 82% (334MB -> 62MB)
and speeds up end-to-end single-threaded report generation by 10%. For
reference the compressed name data in llc is 81MB (__llvm_prf_names).

Rationale for changes to the format:

- With the current format, most coverage function records are discarded.
E.g., more than 97% of the records in llc are *duplicate* placeholders
for functions visible-but-not-used in TUs. Placeholders *are* used to
show under-covered functions, but duplicate placeholders waste space.

- We reached general consensus about giving (1) a try at the 2017 code
coverage BoF [1]. The thinking was that using `linkonce_odr` to merge
duplicates is simpler than alternatives like teaching build systems
about a coverage-aware database/module/etc on the side.

- Revising the format is expensive due to the backwards compatibility
requirement, so we might as well compress filenames while we're at it.
This shrinks the encoded filenames in llc by 86% (12MB -> 1.6MB).

See CoverageMappingFormat.rst for the details on what exactly has
changed.

Fixes PR34533 [2], hopefully.

[1] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html
[2] https://bugs.llvm.org/show_bug.cgi?id=34533

Differential Revision: https://reviews.llvm.org/D69471

show more ...

llvm.coverage.FunctionRecord - fix uninitialized variable warning. NFCI.

[Coverage] Speed up file-based queries for coverage info, NFC

Speed up queries for coverage info in a file by reducing the amount of
time spent determining whether a function record corresponds to a

[Coverage] Speed up file-based queries for coverage info, NFC

Speed up queries for coverage info in a file by reducing the amount of
time spent determining whether a function record corresponds to a file.

This gives a 36% speedup when generating a coverage report for `llc`.
The reduction is entirely in user time.

rdar://54758110

Differential Revision: https://reviews.llvm.org/D67575

llvm-svn: 372025

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Ignore object files that lack coverage information.

Before this change, if multiple binary files were presented, all of them must have been instrumented or the load would fail with coverage_map_erro

Ignore object files that lack coverage information.

Before this change, if multiple binary files were presented, all of them must have been instrumented or the load would fail with coverage_map_error::no_data_found.

Patch by Dean Sturtevant.

Differential Revision: https://reviews.llvm.org/D66763

llvm-svn: 370257

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