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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-05 11:24:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-05 11:24:05 -0700
commit3fe617ccafd6f5bb33c2391d6f4eeb41c1fd0151 (patch)
tree3a0ad37eae9ad7e872af6d631431384e0c6e7a37
parentfd47ff55c9c31101fcc06d20cb381da3d4089bd5 (diff)
downloadlinux-3fe617ccafd6f5bb33c2391d6f4eeb41c1fd0151.tar.bz2
Enable '-Werror' by default for all kernel builds
... but make it a config option so that broken environments can disable it when required. We really should always have a clean build, and will disable specific over-eager warnings as required, if we can't fix them. But while I fairly religiously enforce that in my own tree, it doesn't get enforced by various build robots that don't necessarily report warnings. So this just makes '-Werror' a default compiler flag, but allows people to disable it for their configuration if they have some particular issues. Occasionally, new compiler versions end up enabling new warnings, and it can take a while before we have them fixed (or the warnings disabled if that is what it takes), so the config option allows for that situation. Hopefully this will mean that I get fewer pull requests that have new warnings that were not noticed by various automation we have in place. Knock wood. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Makefile3
-rw-r--r--init/Kconfig14
2 files changed, 17 insertions, 0 deletions
diff --git a/Makefile b/Makefile
index 6bc1c5b17a62..d45fc2edf186 100644
--- a/Makefile
+++ b/Makefile
@@ -785,6 +785,9 @@ stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
KBUILD_CFLAGS += $(stackp-flags-y)
+KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
+KBUILD_CFLAGS += $(KBUILD_CFLAGS-y)
+
ifdef CONFIG_CC_IS_CLANG
KBUILD_CPPFLAGS += -Qunused-arguments
# The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable.
diff --git a/init/Kconfig b/init/Kconfig
index e708180e9a59..8cb97f141b70 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -137,6 +137,20 @@ config COMPILE_TEST
here. If you are a user/distributor, say N here to exclude useless
drivers to be distributed.
+config WERROR
+ bool "Compile the kernel with warnings as errors"
+ default y
+ help
+ A kernel build should not cause any compiler warnings, and this
+ enables the '-Werror' flag to enforce that rule by default.
+
+ However, if you have a new (or very old) compiler with odd and
+ unusual warnings, or you have some architecture with problems,
+ you may need to disable this config option in order to
+ successfully build the kernel.
+
+ If in doubt, say Y.
+
config UAPI_HEADER_TEST
bool "Compile test UAPI headers"
depends on HEADERS_INSTALL && CC_CAN_LINK