MINOR: compiler: rely on builtin detection for __builtin_unreachable()

Due to __builtin_unreachable() only being associated to gcc 4.5 and
above, it turns out it was not enabled for clang. It's not used *that*
much but still a little bit, so let's enable it now. This reduces the
code size by 0.2% and makes it a bit more efficient.
This commit is contained in:
Willy Tarreau 2024-12-17 09:10:53 +01:00
parent 96cfcb1df3
commit 41fc18b1d1

View File

@ -191,6 +191,11 @@
#define __read_mostly HA_SECTION("read_mostly")
#endif
/* __builtin_unreachable() was added in gcc 4.5 */
#if defined(__GNUC__) && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))
#define __has_builtin___builtin_unreachable 1
#endif
/* This allows gcc to know that some locations are never reached, for example
* after a longjmp() in the Lua code, hence that some errors caught by such
* methods cannot propagate further. This is important with gcc versions 6 and
@ -200,7 +205,7 @@
#ifdef DEBUG_USE_ABORT
#define my_unreachable() abort()
#else
#if defined(__GNUC__) && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))
#if __has_builtin(__builtin_unreachable)
#define my_unreachable() __builtin_unreachable()
#else
#define my_unreachable() do { } while (1)