[Bug c/11370] New: -Wunreachable-code gives false complaints

[debian-gcc at lists dot debian dot org]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11370

           Summary: -Wunreachable-code gives false complaints
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: debian-gcc at lists dot debian dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i386-linux
  GCC host triplet: i386-linux
GCC target triplet: i386-linux

[forwarded from http://bugs.debian.org/196600]

rechecked with HEAD.

  Gcc complains that a declaration "will never be executed" for a
code path that executes, as shown below.
If I:
 . remove the exit line
 . change "int ix;" to "int ix = 0;"
or
 . move the declaration to line 2 or after line 3
the complaint go away.

$ cat -n test.c
#include <stdio.h>

int main(int argc, char *argv[]) { /* line 3 */
  if (argc != 1) exit(1);

  {
    int ix;                     /* line 7 */
    ix = printf("hello\n");
    printf("%d\n", ix);
  }

  return 0;
}

$ gcc-3.3 -Wunreachable-code test.c; ./a.out 
test.c: In function `main':
test.c:7: warning: will never be executed
hello
6