Disable spurious -Wstringop-overflow for setjmp/longjmp (bug 26647)

[DJ Delorie]

Joseph Myers <joseph@codesourcery.com> writes:
> diff --git a/csu/libc-start.c b/csu/libc-start.c
> +#include <libc-diag.h>

Ok.

> +  DIAG_PUSH_NEEDS_COMMENT;
> +#if __GNUC_PREREQ (7, 0)
> +  /* This call results in a -Wstringop-overflow warning because struct
> +     pthread_unwind_buf is smaller than jmp_buf.  setjmp and longjmp
> +     do not use anything beyond the common prefix (they never access
> +     the saved signal mask), so that is a false positive.  */
> +  DIAG_IGNORE_NEEDS_COMMENT (11, "-Wstringop-overflow=");
> +#endif
>    not_first_call = setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf);
> +  DIAG_POP_NEEDS_COMMENT;

Ok.  Matches all other uses throughout the tree.

> diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
> +#include <libc-diag.h>

Ok.

> +  DIAG_PUSH_NEEDS_COMMENT;
> +#if __GNUC_PREREQ (7, 0)
> +  /* This call results in a -Wstringop-overflow warning because struct
> +     pthread_unwind_buf is smaller than jmp_buf.  setjmp and longjmp
> +     do not use anything beyond the common prefix (they never access
> +     the saved signal mask), so that is a false positive.  */
> +  DIAG_IGNORE_NEEDS_COMMENT (11, "-Wstringop-overflow=");
> +#endif
>    not_first_call = setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf);
> +  DIAG_POP_NEEDS_COMMENT;

Ok.

> diff --git a/nptl/unwind.c b/nptl/unwind.c
> +#include <libc-diag.h>

Ok.

> +  DIAG_PUSH_NEEDS_COMMENT;
> +#if __GNUC_PREREQ (7, 0)
> +  /* This call results in a -Wstringop-overflow warning because struct
> +     pthread_unwind_buf is smaller than jmp_buf.  setjmp and longjmp
> +     do not use anything beyond the common prefix (they never access
> +     the saved signal mask), so that is a false positive.  */
> +  DIAG_IGNORE_NEEDS_COMMENT (11, "-Wstringop-overflow=");
> +#endif
>    if (do_longjump)
>      __libc_unwind_longjmp ((struct __jmp_buf_tag *) buf->cancel_jmp_buf, 1);
> +  DIAG_POP_NEEDS_COMMENT;

Ok.

LGTM.

Reviewed-by: DJ Delorie <dj@redhat.com>