[Bug c/19058] New: setjmp: 4.0 fails to give 'clobbered' warning (regression from 3.4.1)

["bh at techhouse dot brown dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

In the code that follows, gcc-3.4.1 says:
> gcc -W -Wall  -Wno-unused-parameter qux.c -O2
qux.c:13: warning: variable 'x' might be clobbered by `longjmp' or `vfork'

gcc-4.0 with those same options gives no warning.

Note that neither version warns about 'sum' being clobbered.


#include <signal.h>
#include <setjmp.h>
#include <stdio.h>

static jmp_buf jmpbuf;

static void segv_handler(int sig) {
    longjmp(jmpbuf, 1);
}

int main() {
    int y = 1;
    volatile int *x = &y;
    int sum = 0;

    signal(SIGSEGV, segv_handler);

    if(setjmp(jmpbuf) == 0) {
        while(1) {
            sum += *x;
            x++;
        }
    }

    printf("%d\n", sum);
    return sum;
}

-- 
           Summary: setjmp: 4.0 fails to give 'clobbered' warning
                    (regression from 3.4.1)
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bh at techhouse dot brown dot edu
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19058