From: Johannes Berg <johannes.berg@xxxxxxxxx>
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@xxxxxxxx>
Fixes: 7322dd755e7d ("byteswap: try to avoid __builtin_constant_p gcc bug")
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
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
--
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