l...@gnu.org (Ludovic Courtès) skribis:
> void foo (char *x, char *y)
> {
> /* MEMCPY (x, str, sizeof str); */
> MEMCPY (y, "this is a literal /gnu/store string", 35);
> }
This was not a correct example because “/gnu/store” must be followed by
at least 34 chars for the patch to work. And indeed, it does work in
this case:
--8<---------------cut here---------------start------------->8---
$ cat strmov.c
#define _GNU_SOURCE
#include <string.h>
static const char str[] = "MEMpCPY /gnu/store/THIS IS A LONG STRING, A VERY,
VERY, VERY LOOOOONG STRING";
extern char *p, *q;
#ifndef MEMCPY
# define MEMCPY memcpy
#endif
void foo (char *x, char *y)
{
/* MEMCPY (x, str, sizeof str); */
MEMCPY (y, "this is a literal /gnu/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
string", 35);
}
$ guix environment --ad-hoc gcc-toolchain@5 -C -- gcc -O2 -c strmov.c
$ objdump -S strmov.o |grep movabs
--8<---------------cut here---------------end--------------->8---
So the real issue is this:
> The second issue is that the patch only ever worked with literal
> strings. It does not “see” strings in constant arrays like the ‘str’
> array in the example above.
Ludo’.
