ZequanWu wrote: > > I think there should be a proper Clang flag to control this, instead of > > requiring users to pass internal `-mllvm` flags. (Also the flag should be > > well documented.) > > I believe Zequan did that at one point, but he ran into the problem that Rust > and Clang need to agree on the coverage metadata section flags. Using an > mllvm flag means we can opt into the new mode for both clang and rust > simultaneously, hopefully without waiting for rustc changes.
Since I modified clang CoverageMappingGen.cpp to conditionally add toggle this new mode in __llvm_profile_raw_version variable, rustc needs to do similar change at frontend in order to use this with code coverage. The problem I ran into is chromium unittests have rust code. When I tried this mode for base_unittests, the Rust binaries are not able to use this mode while the C/C++ binaries uses it. So, the generated raw profiles are mixture of Rust raw profiles (counters + metadata sections) + C/C++ raw profiles (counters). llvm-profdata is currently not able to handle this. My plan is to fix this in llvm-profdata later to allow merging with mixture raw profiles. I'm not sure if we can pass -mllvm flag to rustc. https://github.com/llvm/llvm-project/pull/69493 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
