Messages in this thread Patch in this message | | | From | Johannes Berg <> | Subject | [PATCH] byteswap: don't use __builtin_bswap*() with sparse | Date | Thu, 11 Aug 2016 13:15:02 +0200 |
| |
From: Johannes Berg <johannes.berg@intel.com>
Although sparse declares __builtin_bswap*(), it can't actually do constant folding inside them (yet). As such, things like
switch (protocol) { case htons(ETH_P_IP): break; }
which we do all over the place cause sparse to warn that it expects a constant instead of a function call.
Disable __HAVE_BUILTIN_BSWAP*__ if __CHECKER__ is defined to avoid this.
Cc: Arnd Bergmann <arnd@arndb.de> Fixes: 7322dd755e7d ("byteswap: try to avoid __builtin_constant_p gcc bug") Signed-off-by: Johannes Berg <johannes.berg@intel.com> --- include/linux/compiler-gcc.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index e2949397c19b..8dbc8929a6a0 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -242,7 +242,11 @@ */ #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) -#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP +/* + * sparse (__CHECKER__) pretends to be gcc, but can't do constant + * folding in __builtin_bswap*() (yet), so don't set these for it. + */ +#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__) #if GCC_VERSION >= 40400 #define __HAVE_BUILTIN_BSWAP32__ #define __HAVE_BUILTIN_BSWAP64__ @@ -250,7 +254,7 @@ #if GCC_VERSION >= 40800 #define __HAVE_BUILTIN_BSWAP16__ #endif -#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */ +#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */ #if GCC_VERSION >= 50000 #define KASAN_ABI_VERSION 4 -- 2.8.1
| |