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.
Signed-off-by: Tri Vo <tr...@android.com>
---
Documentation/dev-tools/gcov.rst | 18 ++++++++++++++----
1 file 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
---------------
--
2.20.1.321.g9e740568ce-goog
