[PATCH] D83154: clang: Add -fcoverage-prefix-map

[Reid "Away June-Sep" Kleckner via Phabricator via cfe-commits]

rnk added inline comments.


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Comment at: clang/include/clang/Driver/Options.td:1980
     HelpText<"remap file source paths in debug info">;
+def fprofile_prefix_map_QA
+  : Joined<["-"], "fprofile-prefix-map=">, Group<f_Group>,
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Any reason for the _QA suffix instead of _EQ?


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Comment at: clang/lib/CodeGen/CoverageMappingGen.cpp:1334
+  llvm::SmallString<256> Path(Filename);
+  llvm::sys::fs::make_absolute(Path);
+  llvm::sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
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Please only make the path absolute if nothing in the prefix map matches. Otherwise, the user must embed the CWD into the prefix map, which is needlessly difficult for the build system. I believe it is also consistent with the way that the debug info prefix map works. It appears to operate on the possibly relative source paths received on the command line (-I...).


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Comment at: clang/test/Profile/profile-prefix-map.c:12
+
+// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -mllvm -enable-name-compression=false -main-file-name profile-prefix-map.c nested/profile-prefix-map.c -fprofile-prefix-map=%/t/root=. -o - | FileCheck --check-prefix=PROFILE-PREFIX-MAP %s --implicit-check-not=root
+//
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See here, for example, where you must pass `-fprofile-prefix-map=%/t/...`.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D83154/new/

https://reviews.llvm.org/D83154