On Thu, Jul 05, 2018 at 08:57:26AM -0700, Bart Van Assche wrote:
> Both sparse and smatch identify themselves as gcc. However, neither
> static analyzer supports any of the __builtin_*_overflow() functions.
> Hence do not define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW for these
> static checkers.
>
> Fixes: f0907827a8a9 ("compiler.h: enable builtin overflow checkers and add fallback code")
> Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
> Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Cc: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> ---
> include/linux/compiler-gcc.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
> index f1a7492a5cc8..15e55b89e952 100644
> --- a/include/linux/compiler-gcc.h
> +++ b/include/linux/compiler-gcc.h
> @@ -344,6 +344,6 @@
> */
> #define uninitialized_var(x) x = x
>
> -#if GCC_VERSION >= 50100
> +#if GCC_VERSION >= 50100 && !defined(__CHECKER__)
> #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
> #endif
> --
Hi,
A similar patch has already been posted 2 or 3 weeks ago [1].
Also, the development version of sparse [2] supports the
__builtin_*_overflow() functions *and* supports the __has_builtin()
macro. So I think it's preferable to use __has_builtin(),
at least for sparse (maybe smatch is interested in it too).
-- Luc Van Oostenryck
[1] https://lore.kernel.org/lkml/alpine.LSU.2.21.1806071258310.7958@xxxxxxxxxxxxx/
[2] git://github.com/lucvoo/sparse.git
