diff options
| author | Nathan Chancellor <nathan@kernel.org> | 2026-02-23 12:10:28 -0700 |
|---|---|---|
| committer | Nicolas Schier <nsc@kernel.org> | 2026-03-12 12:52:37 +0100 |
| commit | ec4c28276c140a9338700041112f64f8d7ccc3e9 (patch) | |
| tree | c88b94968b5026ce0877505f2c06b205c16f83e3 /Makefile | |
| parent | febb5c81fa8df999e24877f6226f8cba9f06ce6a (diff) | |
| download | linux-next-history-ec4c28276c140a9338700041112f64f8d7ccc3e9.tar.gz | |
kbuild: Consolidate C dialect options
Introduce CC_FLAGS_DIALECT to make it easier to update the various
places in the tree that rely on the GNU C standard and Microsoft
extensions flags atomically. All remaining uses of '-std=gnu11' and
'-fms-extensions' are in the tools directory (which has its own build
system) and other standalone Makefiles. This will allow the kernel to
use a narrower option to enable the Microsoft anonymous tagged structure
extension in a simpler manner. Place the CC_FLAGS_DIALECT block after
the configuration include (so that a future change can move the
selection of the flag to Kconfig) but before the
arch/$(SRCARCH)/Makefile include (so that CC_FLAGS_DIALECT is available
for use in those Makefiles).
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Link: https://patch.msgid.link/20260223-fms-anonymous-structs-v1-1-8ee406d3c36c@kernel.org
Signed-off-by: Nicolas Schier <nsc@kernel.org>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/Makefile b/Makefile index e944c6e71e81f..06ff3032a6bc4 100644 --- a/Makefile +++ b/Makefile @@ -587,7 +587,6 @@ LINUXINCLUDE := \ KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE KBUILD_CFLAGS := -KBUILD_CFLAGS += -std=gnu11 KBUILD_CFLAGS += -fshort-wchar KBUILD_CFLAGS += -funsigned-char KBUILD_CFLAGS += -fno-common @@ -790,6 +789,18 @@ ifdef need-config include $(objtree)/include/config/auto.conf endif +CC_FLAGS_DIALECT := -std=gnu11 +# Allow including a tagged struct or union anonymously in another struct/union. +CC_FLAGS_DIALECT += -fms-extensions +# Clang enables warnings about GNU and Microsoft extensions by default, disable +# them because this is expected with the above options. +ifdef CONFIG_CC_IS_CLANG +CC_FLAGS_DIALECT += -Wno-gnu +CC_FLAGS_DIALECT += -Wno-microsoft-anon-tag +endif +export CC_FLAGS_DIALECT +KBUILD_CFLAGS += $(CC_FLAGS_DIALECT) + ifeq ($(KBUILD_EXTMOD),) # Objects we will link into vmlinux / subdirs we need to visit core-y := @@ -1093,9 +1104,6 @@ NOSTDINC_FLAGS += -nostdinc # perform bounds checking. KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3) -# Allow including a tagged struct or union anonymously in another struct/union. -KBUILD_CFLAGS += -fms-extensions - # disable invalid "can't wrap" optimizations for signed / pointers KBUILD_CFLAGS += -fno-strict-overflow |