From: Masahiro Yamada <masahiroy@xxxxxxxxxx> [ Upstream commit 3bed1b7b9d79ca40e41e3af130931a3225e951a3 ] 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@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- scripts/Kconfig.include | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include index 3b2861f47709b..79455ad6b3863 100644 --- a/scripts/Kconfig.include +++ b/scripts/Kconfig.include @@ -20,7 +20,7 @@ success = $(if-success,$(1),y,n) # $(cc-option,<flag>) # Return y if the compiler supports <flag>, n otherwise -cc-option = $(success,$(CC) -Werror $(CLANG_FLAGS) $(1) -E -x c /dev/null -o /dev/null) +cc-option = $(success,$(CC) -Werror $(CLANG_FLAGS) $(1) -S -x c /dev/null -o /dev/null) # $(ld-option,<flag>) # Return y if the linker supports <flag>, n otherwise -- 2.20.1
