Bug#196600: gcc -Wunreachable-code gives false complaints

[Karl Hammar <karl@kalle.csb.ki.se>]

Package: gcc-3.3
Version: 3.3-2

  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-2.95 -Wunreachable-code test.c
cc1: Invalid option `-Wunreachable-code'
$ gcc-3.0 -Wunreachable-code test.c; ./a.out 
hello
6
$ gcc-3.2 -Wunreachable-code test.c; ./a.out 
test.c: In function `main':
test.c:7: warning: will never be executed
hello
6
$ gcc-3.3 -Wunreachable-code test.c; ./a.out 
test.c: In function `main':
test.c:7: warning: will never be executed
hello
6
$ dpkg -l gcc-\?.\? | grep ^i
ii  gcc-3.0        3.0.4-7        The GNU C compiler.
ii  gcc-3.2        3.2.3-0pre9    The GNU C compiler
ii  gcc-3.3        3.3-2          The GNU C compiler
$

Regards,
/Karl

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Karl Hammar                    Aspö Data           karl@kalle.csb.ki.se
Lilla Aspö 2340                                                Networks
S-742 94 Östhammar          +46  173 140 57                   Computers
Sweden                     +46  70 511 97 84                 Consulting
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