Hi Martin,
On Wed, Feb 06, 2019 at 05:28:08PM -0700, Martin Sebor wrote:
> void
> -__clear_cache (char *beg __attribute__((__unused__)),
> - char *end __attribute__((__unused__)))
> +__clear_cache (void *beg __attribute__((__unused__)),
> + void *end __attribute__((__unused__)))
> {
> #ifdef CLEAR_INSN_CACHE
> - CLEAR_INSN_CACHE (beg, end);
> + /* Cast the void* pointers to char* as some implementations
> + of the macro assume the pointers can be subtracted from
> + one another. */
> + CLEAR_INSN_CACHE ((char *) beg, (char *) end);
> #endif /* CLEAR_INSN_CACHE */
> }
You can subtract pointers to void in GCC just fine, it's a GNU C extension.
See extend.texi:
In GNU C, addition and subtraction operations are supported on pointers to
@code{void} and on pointers to functions. This is done by treating the
size of a @code{void} or of a function as 1.
(and libgcc is built with GCC always).
Segher
