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| author |   Tri Vo <trong@android.com> | 2019-05-14 15:45:28 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-14 19:52:51 -0700 |
| commit | aa069a23a220e9ab00d6837b76917952d0fb587e (patch) | |
| tree | 1b03a8ca938c8cf0e82b9b7e2f5ee258f179cc90 /Documentation | |
| parent | gcov: clang: move common GCC code into gcc_base.c (diff) | |
| download | linux-dev-aa069a23a220e9ab00d6837b76917952d0fb587e.tar.xz linux-dev-aa069a23a220e9ab00d6837b76917952d0fb587e.zip | |
gcov: docs: add a note on GCC vs Clang differences
Document some things of note to gcov users:
1. GCC gcov and Clang llvm-cov tools are not compatible.
2. The use of GCC vs Clang is transparent at build-time.
Also adjust the documentation to account for the removal of config symbol
CONFIG_GCOV_FORMAT_AUTODETECT by commit 6a61b70b43c9 ("gcov: remove
CONFIG_GCOV_FORMAT_AUTODETECT").
Link: http://lkml.kernel.org/r/20190318025411.98014-4-trong@android.com
Signed-off-by: Tri Vo <trong@android.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: Greg Hackmann <ghackmann@android.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Petri Gynther <pgynther@google.com>
Cc: Prasad Sodagudi <psodagud@quicinc.com>
Cc: Trilok Soni <tsoni@quicinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/dev-tools/gcov.rst | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/Documentation/dev-tools/gcov.rst b/Documentation/dev-tools/gcov.rst index 69a7d90c320a..46aae52a41d0 100644 --- a/Documentation/dev-tools/gcov.rst +++ b/Documentation/dev-tools/gcov.rst @@ -34,10 +34,6 @@ Configure the kernel with:: CONFIG_DEBUG_FS=y CONFIG_GCOV_KERNEL=y -select the gcc's gcov format, default is autodetect based on gcc version:: - - CONFIG_GCOV_FORMAT_AUTODETECT=y - and to get coverage data for the entire kernel:: CONFIG_GCOV_PROFILE_ALL=y @@ -169,6 +165,20 @@ b) gcov is run on the BUILD machine [user@build] gcov -o /tmp/coverage/tmp/out/init main.c +Note on compilers +----------------- + +GCC and LLVM gcov tools are not necessarily compatible. Use gcov_ to work with +GCC-generated .gcno and .gcda files, and use llvm-cov_ for Clang. + +.. _gcov: http://gcc.gnu.org/onlinedocs/gcc/Gcov.html +.. _llvm-cov: https://llvm.org/docs/CommandGuide/llvm-cov.html + +Build differences between GCC and Clang gcov are handled by Kconfig. It +automatically selects the appropriate gcov format depending on the detected +toolchain. + + Troubleshooting --------------- |