diff options
Diffstat (limited to 'listen/listen.h')
| -rw-r--r-- | listen/listen.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/listen/listen.h b/listen/listen.h index 0075bf3..46ec397 100644 --- a/listen/listen.h +++ b/listen/listen.h @@ -1,3 +1,23 @@ +#define GCC_VERSION (__GNUC__ * 10000 \ + + __GNUC_MINOR__ * 100 \ + + __GNUC_PATCHLEVEL__) + +#if GCC_VERSION >= 40500 + +/* + * Mark a position in code as unreachable. This can be used to + * suppress control flow warnings after asm blocks that transfer + * control elsewhere. + * + * Early snapshots of gcc 4.5 don't support this and we can't detect + * this in the preprocessor, but we can live with this because they're + * unreleased. + */ +#define unreachable() \ + do { __builtin_unreachable(); } while (0) +#else +#define unreachable() do { } while (1) +#endif #define T_ERROR 1 #define T_PORT 2 |