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| author | Masahiro Yamada <masahiroy@kernel.org> | 2020-01-17 20:14:35 +0300 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2020-01-22 05:04:28 +0300 |
| commit | 3bed1b7b9d79ca40e41e3af130931a3225e951a3 (patch) | |
| tree | 4b73fc5ee26959c9fce6745f06baaeba594dcc3f /scripts/Kconfig.include | |
| parent | 1a7f0a34ea7d05d1ffcd32c9b1b4e07ac0687538 (diff) | |
| download | linux-3bed1b7b9d79ca40e41e3af130931a3225e951a3.tar.xz | |
kbuild: use -S instead of -E for precise cc-option test in Kconfig
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>
Diffstat (limited to 'scripts/Kconfig.include')
| -rw-r--r-- | scripts/Kconfig.include | 2 |
1 files changed, 1 insertions, 1 deletions
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,<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 |