diff mbox series

[4/4] Kbuild: use -std=gnu11 for KBUILD_USERCFLAGS

Message ID 20220308215615.14183-5-arnd@kernel.org (mailing list archive)
State New, archived
Headers show
Series Kbuild: std=gnu11 changes | expand

Commit Message

Arnd Bergmann March 8, 2022, 9:56 p.m. UTC 
From: Arnd Bergmann <arnd@arndb.de>

As we change the C language standard for the kernel from gnu89 to
gnu11, it makes sense to also update the version for user space
compilation.

Some users have older native compilers than what they use for
kernel builds, so I considered using gnu99 as the default version
for wider compatibility with gcc-4.6 and earlier.

However, testing with older compilers showed that we already require
HOSTCC version 5.1 as well because a lot of host tools include
linux/compiler.h that uses __has_attribute():

  CC      tools/objtool/exec-cmd.o
In file included from tools/include/linux/compiler_types.h:36:0,
                 from tools/include/linux/compiler.h:5,
                 from exec-cmd.c:2:
tools/include/linux/compiler-gcc.h:19:5: error: "__has_attribute" is not defined [-Werror=undef]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 1ba8dc523952..e0b11ddd0760 100644
--- a/Makefile
+++ b/Makefile
@@ -432,7 +432,7 @@  HOSTCXX	= g++
 endif
 
 KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
-			 -O2 -fomit-frame-pointer -std=gnu89 \
+			 -O2 -fomit-frame-pointer -std=gnu11 \
 			 -Wdeclaration-after-statement
 KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
 KBUILD_USERLDFLAGS := $(USERLDFLAGS)