kbuild: use -S instead of -E for precise cc-option test in Kconfig
[ Upstream commit 3bed1b7b ] Currently, -E (stop after the preprocessing stage) is used to check whether the given compiler flag is supported. While it is faster than -S (or -c), it can be false-positive. You need to run the compilation proper to check the flag more precisely. For example, -E and -S disagree about the support of "--param asan-instrument-allocas=1". $ gcc -Werror --param asan-instrument-allocas=1 -E -x c /dev/null -o /dev/null $ echo $? 0 $ gcc -Werror --param asan-instrument-allocas=1 -S -x c /dev/null -o /dev/null cc1: error: invalid --param name ‘asan-instrument-allocas’; did you mean ‘asan-instrument-writes’? $ echo $? 1 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Please register or sign in to comment