[PATCH] D151283: [llvm-cov] Support directory layout in coverage reports

[Gulfem Savrun Yeniceri via Phabricator via llvm-commits]

gulfem added inline comments.


================
Comment at: llvm/test/tools/llvm-cov/directory_coverage.test:1
+// RUN: mkdir -p %t && clang -fprofile-instr-generate=%t/default.profraw -fcoverage-mapping -o %t/main.out \
+// RUN:   %S/Inputs/directory_coverage/main.cc \
----------------
AtomicGu wrote:
> phosek wrote:
> > AtomicGu wrote:
> > > phosek wrote:
> > > > Your test cannot assume that `clang` is available on the host since Clang is not one of LLVM's prerequisites, and we want LLVM to remain compiler agnostic. That's why you're seeing the issue on Windows pre-merge builders: Clang happens to be available on these builders, but it doesn't include the profile runtime, which is perfectly valid because we don't require it.
> > > > 
> > > > What we do instead is to either include raw profile in the `.proftext` textual format and then convert it to `.profdata` using `llvm-profdata` or include `.profdata` directly, plus include coverage mapping information in the textual format as `.covmapping`, and then run `llvm-cov`as part of the test. We also include instructions for recreating the `.profdata` and `.covmapping` files inside the test.
> > > > 
> > > > Here are some examples as an inspiration:
> > > > 
> > > > https://github.com/llvm/llvm-project/blob/96ae0851c26237378fa1280b0a9ad713e1b72bdb/llvm/test/tools/llvm-cov/coverage-prefix-map.test
> > > > https://github.com/llvm/llvm-project/blob/96ae0851c26237378fa1280b0a9ad713e1b72bdb/llvm/test/tools/llvm-cov/multiple-objects.test
> > > > 
> > > I tried this today. `llvm-cov convert-for-testing` works well for single source file program. But when I used it for multiple source files, the generated `.covmapping` file is failed to be load by `llvm-cov show`:
> > > 
> > > ```
> > > error: Failed to load coverage: 'main.covmapping': Malformed coverage data
> > > ```
> > > 
> > > The commands used is same with those in `coverage-prefix-map.test`:
> > > 
> > > ```
> > > cp %S/Inputs/directory_coverage -r . /tmp
> > > cd /tmp/directory_coverage
> > > clang -fprofile-instr-generate -mllvm -enable-name-compression=false \
> > >   -fcoverage-mapping -fcoverage-prefix-map=$PWD=. -o main \
> > >   main.cc a0/a1/a2.cc b0/b1_1.cc b0/b1_2.cc c0/c1/c2_1.cc c0/c1/c2_2.cc
> > > LLVM_PROFILE_FILE="main.raw" ./main
> > > llvm-profdata merge main.raw -o main.profdata
> > > llvm-cov convert-for-testing ./main -o main.covmapping
> > > rm main main.raw
> > > 
> > > llvm-cov report -path-equivalence=.,/tmp/coverage_prefix_map \
> > >   -instr-profile main.profdata main.covmapping
> > > ```
> > > 
> > > Is this a bug or a designed behavior? Can I just include the program file directly for now?
> > That's not expected, I'd try to investigate this further. Did you build all the tools yourself from the latest revision? Did you enable zlib?
> > 
> > We definitely don't want to include the program file directly since that's going to be in the Git history forever and will take extra space.
> I pulled the newest commit and tried again. The problem still exists.
> 
> I checked the CMakeCache.txt. `LLVM_ENABLE_ZLIB` is `ON`.
> 
> Here are the source code, program, profdata and covmapping files: {F28318505}
> 
> Commands to reproduce the issue:
> 
> ```
> llvm-cov report main.covmapping --instr-profile main.profdata
> ```
I was able to reproduce it locally. AFAICT, the error is thrown in the following line:
https://github.com/llvm/llvm-project/blob/main/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp#L720

The issue seems about the filenames. I did not have much time to dig into that yet, but we might be uncovering an issue about `convert-for-testing` flag in `llvm-cov`.  


Repository:
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https://reviews.llvm.org/D151283