https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96798
--- Comment #8 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Iain Sandoe from comment #7)
> (In reply to David Malcolm from comment #6)
> > Thanks! The "memset" call has become a call to "__builtin___memset_chk"
> > (perhaps due to _FORTIFY_SOURCE, or something similar in Darwin's libc?),
>
> (transitive include of strings.h, for macOS >= 10.5)
> usr/include/_types.h:# define _FORTIFY_SOURCE 2 /* on by default */
>
> usr/include/strings.h:
>
> #if defined (__GNUC__) && _FORTIFY_SOURCE > 0 && !defined (__cplusplus)
> /* Security checking functions. */
> #include <secure/_strings.h>
> #endif
>
>
> secure/_strings.h:
>
> #if _USE_FORTIFY_LEVEL > 0
>
> ....
>
> #if __has_builtin(__builtin___memset_chk) || defined(__GNUC__)
> #undef bzero
> /* void bzero(void *s, size_t n) */
> #define bzero(dest, ...) \
> __builtin___memset_chk (dest, 0, __VA_ARGS__, __darwin_obsz0
> (dest))
> #endif
>
Oops hit send too soon.
string.h is a transitive include of strings.h and has:
#if defined (__GNUC__) && _FORTIFY_SOURCE > 0 && !defined (__cplusplus)
/* Security checking functions. */
#include <secure/_string.h>
#endif
_strings.h:
#if __IPHONE_OS_VERSION_MIN_REQUIRED >= 70000 ||
__MAC_OS_X_VERSION_MIN_REQUIRED >= 1090 || \
defined(__DRIVERKIT_VERSION_MIN_REQUIRED)
#if __has_builtin(__builtin___memccpy_chk) && __HAS_FIXED_CHK_PROTOTYPES
#undef memccpy
/* void *memccpy(void *dst, const void *src, int c, size_t n) */
#define memccpy(dest, ...) \
__builtin___memccpy_chk (dest, __VA_ARGS__, __darwin_obsz0
(dest))
#endif
#endif
So.. essentially, the checked builtins are going to be used everywhere by
default on modern Darwin (and some are going to be used even on venerable
Darwin).
