From 3bed1b7b9d79ca40e41e3af130931a3225e951a3 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 18 Jan 2020 02:14:35 +0900 Subject: kbuild: use -S instead of -E for precise cc-option test in Kconfig MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- scripts/Kconfig.include | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/Kconfig.include') diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include index d4adfbe42690..bfb44b265a94 100644 --- a/scripts/Kconfig.include +++ b/scripts/Kconfig.include @@ -25,7 +25,7 @@ failure = $(if-success,$(1),n,y) # $(cc-option,) # Return y if the compiler supports , 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,) # Return y if the linker supports , n otherwise -- cgit v1.2.3-59-g8ed1b