[Coverage][Expansion] handle nested macros in scratch space (#89869)

The problematic program is as follows:

```shell
#define pre_a 0
#define PRE(x) pre_##x

void f(void) {
PRE(a) && 0;

[Coverage][Expansion] handle nested macros in scratch space (#89869)

The problematic program is as follows:

```shell
#define pre_a 0
#define PRE(x) pre_##x

void f(void) {
PRE(a) && 0;
}

int main(void) { return 0; }
```

in which after token concatenation (`##`), there's another nested macro
`pre_a`.

Currently only the outer expansion region will be produced. ([compiler
explorer
link](https://godbolt.org/#g:!((g:!((g:!((h:codeEditor,i:(filename:'1',fontScale:14,fontUsePx:'0',j:1,lang:___c,selection:(endColumn:29,endLineNumber:8,positionColumn:29,positionLineNumber:8,selectionStartColumn:29,selectionStartLineNumber:8,startColumn:29,startLineNumber:8),source:'%23define+pre_a+0%0A%23define+PRE(x)+pre_%23%23x%0A%0Avoid+f(void)+%7B%0A++++PRE(a)+%26%26+0%3B%0A%7D%0A%0Aint+main(void)+%7B+return+0%3B+%7D'),l:'5',n:'0',o:'C+source+%231',t:'0')),k:51.69491525423727,l:'4',n:'0',o:'',s:0,t:'0'),(g:!((g:!((h:compiler,i:(compiler:cclang_assertions_trunk,filters:(b:'0',binary:'1',binaryObject:'1',commentOnly:'0',debugCalls:'1',demangle:'0',directives:'0',execute:'0',intel:'0',libraryCode:'1',trim:'1',verboseDemangling:'0'),flagsViewOpen:'1',fontScale:14,fontUsePx:'0',j:2,lang:___c,libs:!(),options:'-fprofile-instr-generate+-fcoverage-mapping+-fcoverage-mcdc+-Xclang+-dump-coverage-mapping+',overrides:!(),selection:(endColumn:1,endLineNumber:1,positionColumn:1,positionLineNumber:1,selectionStartColumn:1,selectionStartLineNumber:1,startColumn:1,startLineNumber:1),source:1),l:'5',n:'0',o:'+x86-64+clang+(assertions+trunk)+(Editor+%231)',t:'0')),k:34.5741843594503,l:'4',m:28.903654485049834,n:'0',o:'',s:0,t:'0'),(g:!((h:output,i:(compilerName:'x86-64+clang+(trunk)',editorid:1,fontScale:14,fontUsePx:'0',j:2,wrap:'1'),l:'5',n:'0',o:'Output+of+x86-64+clang+(assertions+trunk)+(Compiler+%232)',t:'0')),header:(),l:'4',m:71.09634551495017,n:'0',o:'',s:0,t:'0')),k:48.30508474576271,l:'3',n:'0',o:'',t:'0')),l:'2',m:100,n:'0',o:'',t:'0')),version:4))

```text
f:
File 0, 4:14 -> 6:2 = #0
Decision,File 0, 5:5 -> 5:16 = M:0, C:2
Expansion,File 0, 5:5 -> 5:8 = #0 (Expanded file = 1)
File 0, 5:15 -> 5:16 = #1
Branch,File 0, 5:15 -> 5:16 = 0, 0 [2,0,0]
File 1, 2:16 -> 2:23 = #0
File 2, 1:15 -> 1:16 = #0
File 2, 1:15 -> 1:16 = #0
Branch,File 2, 1:15 -> 1:16 = 0, 0 [1,2,0]
```

The inner expansion region isn't produced because:

1. In the range-based for loop quoted below, each sloc is processed and
possibly emit a corresponding expansion region.
2. For our sloc in question, its direct parent returned by
`getIncludeOrExpansionLoc()` is a `<scratch space>`, because that's how
`##` is processed.


https://github.com/llvm/llvm-project/blob/88b6186af3908c55b357858eb348b5143f21c289/clang/lib/CodeGen/CoverageMappingGen.cpp#L518-L520

3. This `<scratch space>` cannot be found in the FileID mapping so
`ParentFileID` will be assigned an `std::nullopt`


https://github.com/llvm/llvm-project/blob/88b6186af3908c55b357858eb348b5143f21c289/clang/lib/CodeGen/CoverageMappingGen.cpp#L521-L526

4. As a result this iteration of for loop finishes early and no
expansion region is added for the sloc.

This problem gets worse with MC/DC: as the example shows, there's a
branch from File 2 but File 2 itself is missing. This will trigger
assertion failures.

The fix is more or less a workaround and takes a similar approach as
#89573.

~~Depends on #89573.~~ This includes #89573. Kudos to @chapuni!
This and #89573 together fix #87000: I tested locally, both the reduced
program and my original use case (fwiw, Linux kernel) can run
successfully.

---------

Co-authored-by: NAKAMURA Takumi <geek4civic@gmail.com>

show more ...

Use functions with prototypes when appropriate; NFC

A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a protot

Use functions with prototypes when appropriate; NFC

A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,

void func();

becomes

void func(void);

This is the fifth batch of tests being updated (there are a significant
number of other tests left to be updated).

Note, the behavior of -ast-print is broken. It prints functions with a
prototype (void) as if they have no prototype () in C. Some tests need
to disable strict prototype checking when recompiling the results of an
-ast-print invocation.

show more ...

[Coverage] Emit gap region after conditions when macro is present.

[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

show more ...

[Coverage] Add empty line regions to SkippedRegions

Differential Revision: https://reviews.llvm.org/D84988

Revert "[Coverage] Enable emitting gap area between macros"

This reverts commit a31c89c1b7a0a2fd3e2c0b8a587a60921abf4abd.

[Coverage] Enable emitting gap area between macros

Differential Revision: https://reviews.llvm.org/D85176

Reland [Coverage] Add comment to skipped regions

Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=45757.
Add comment to skipped regions so we don't track execution count for lines containing o

Reland [Coverage] Add comment to skipped regions

Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=45757.
Add comment to skipped regions so we don't track execution count for lines containing only comments.

Differential Revision: https://reviews.llvm.org/D83592

show more ...

Revert abd45154b "[Coverage] Add comment to skipped regions"

This casued assertions during Chromium builds. See comment on the code review

> Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=4

Revert abd45154b "[Coverage] Add comment to skipped regions"

This casued assertions during Chromium builds. See comment on the code review

> Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=45757.
> Add comment to skipped regions so we don't track execution count for lines containing only comments.
>
> Differential Revision: https://reviews.llvm.org/D84208

This reverts commit abd45154bdb6b76c5b480455eacc8c75b08242aa and the
follow-up 87d725473380652bbe845fd2fbd9c0507a55172f.

show more ...

[Coverage] Add comment to skipped regions

Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=45757.
Add comment to skipped regions so we don't track execution count for lines containing only com

[Coverage] Add comment to skipped regions

Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=45757.
Add comment to skipped regions so we don't track execution count for lines containing only comments.

Differential Revision: https://reviews.llvm.org/D84208

show more ...

[Coverage] Fix PR39258: support coverage regions that start deeper than they end

popRegions used to assume that the start location of a region can't be
nested deeper than the end location, which is

[Coverage] Fix PR39258: support coverage regions that start deeper than they end

popRegions used to assume that the start location of a region can't be
nested deeper than the end location, which is not always true.

Patch by Orivej Desh!

Differential Revision: https://reviews.llvm.org/D53244

llvm-svn: 347262

show more ...

[Coverage] Emit gap areas in braces-optional statements (PR35387)

Emit a gap area starting after the r-paren location and ending at the
start of the body for the braces-optional statements (for, for

[Coverage] Emit gap areas in braces-optional statements (PR35387)

Emit a gap area starting after the r-paren location and ending at the
start of the body for the braces-optional statements (for, for-each,
while, etc). The count for the gap area equal to the body's count. This
extends the fix in r317758.

Fixes PR35387, rdar://35570345

Testing: stage2 coverage-enabled build of clang, check-clang
llvm-svn: 319373

show more ...

[Coverage] Suppress creating a code region if the same area is covered by an expansion region.

In most cases these code regions are just redundant, but sometimes they
could be assigned to the counte

[Coverage] Suppress creating a code region if the same area is covered by an expansion region.

In most cases these code regions are just redundant, but sometimes they
could be assigned to the counter of the parent code region instead of
the counter of the nested block.

Differential Revision: https://reviews.llvm.org/D23987

llvm-svn: 280199

show more ...

[Coverage] Prevent creating a redundant counter if a nested body ends with a macro.

If there were several nested statements arranged in a way that all of them
end up with the same macro, then the ex

[Coverage] Prevent creating a redundant counter if a nested body ends with a macro.

If there were several nested statements arranged in a way that all of them
end up with the same macro, then the expansion of this macro was assigned
with all the corresponding counters of these statements.
As a result, the wrong counter value was shown for the macro in llvm-cov.

This patch fixes the issue by preventing adding a counter for an expanded
source range if it already has an assigned counter, which is expected
to come from the most specific statement.

Differential Revision: https://reviews.llvm.org/D23160

llvm-svn: 279962

show more ...

[PGO] cc1 option name change for profile instrumentation

This patch changes cc1 option -fprofile-instr-generate to an enum option
-fprofile-instrument={clang|none}. It also changes cc1 options
-fpro

[PGO] cc1 option name change for profile instrumentation

This patch changes cc1 option -fprofile-instr-generate to an enum option
-fprofile-instrument={clang|none}. It also changes cc1 options
-fprofile-instr-generate= to -fprofile-instrument-path=.
The driver level option -fprofile-instr-generate and -fprofile-instr-generate=
remain intact. This change will pave the way to integrate new PGO
instrumentation in IR level.

Review: http://reviews.llvm.org/D16730
llvm-svn: 259811

show more ...

InstrProf: Rewrite most of coverage mapping generation in a simpler way

The coverage mapping generation code previously generated a large
number of redundant coverage regions and then tried to merge

InstrProf: Rewrite most of coverage mapping generation in a simpler way

The coverage mapping generation code previously generated a large
number of redundant coverage regions and then tried to merge similar
ones back together. This then relied on some awkward heuristics to
prevent combining of regions that were importantly different but
happened to have the same count. The end result was inefficient and
hard to follow.

Now, we more carefully create the regions we actually want. This makes
it much easier to create regions at precise locations as well as
making the basic approach quite a bit easier to follow. There's still
a fair bit of complexity here dealing with included code and macro
expansions, but that's pretty hard to avoid without significantly
reducing the quality of data we provide.

I had to modify quite a few tests where the source ranges became more
precise or the old ranges seemed to be wrong anyways, and I've added
quite a few new tests since a large number of constructs didn't seem
to be tested before.

llvm-svn: 229748

show more ...

InstrProf: Remove CoverageMapping::HasCodeBefore, it isn't used

llvm-svn: 228035

Add tests for coverage mapping generation.

This patch adds the tests for the coverage mapping generation.
Most of the tests check the mapping regions produced by
the generator, and one checks the

Add tests for coverage mapping generation.

This patch adds the tests for the coverage mapping generation.
Most of the tests check the mapping regions produced by
the generator, and one checks the llvm IR.

Differential Revision: http://reviews.llvm.org/D4847

llvm-svn: 215995

show more ...

Add tests for coverage mapping generation.

This patch adds the tests for the coverage mapping generation.
Most of the tests check the mapping regions produced by
the generator, and one checks the

Add tests for coverage mapping generation.

This patch adds the tests for the coverage mapping generation.
Most of the tests check the mapping regions produced by
the generator, and one checks the llvm IR.

Differential Revision: http://reviews.llvm.org/D4793

llvm-svn: 215261

show more ...