Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 273/344] kbuild: use -S instead of -E for precise cc-option test in Kconfig | Date | Fri, 21 Feb 2020 08:41:12 +0100 |
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From: Masahiro Yamada <masahiroy@kernel.org>
[ 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@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- scripts/Kconfig.include | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include index d4adfbe426903..bfb44b265a948 100644 --- a/scripts/Kconfig.include +++ b/scripts/Kconfig.include @@ -25,7 +25,7 @@ failure = $(if-success,$(1),n,y) # $(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
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