gcc/testsuite/gcc.c-torture/execute/fprintf-2.c

   1 /* Verify that calls to fprintf don't get eliminated even if their
   2    result on success can be computed at compile time (they can fail).
   3    The calls can still be transformed into those of other functions.
   4    { dg-skip-if "requires io" { freestanding } } */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9
  10 int main (void)
  11 {
  12   char *tmpfname = tmpnam (0);
  13   FILE *f = fopen (tmpfname, "w");
  14   if (!f)
  15     {
  16       perror ("fopen for writing");
  17       return 1;
  18     }
  19
  20   fprintf (f, "1");
  21   fprintf (f, "%c", '2');
  22   fprintf (f, "%c%c", '3', '4');
  23   fprintf (f, "%s", "5");
  24   fprintf (f, "%s%s", "6", "7");
  25   fprintf (f, "%i", 8);
  26   fprintf (f, "%.1s\n", "9x");
  27   fclose (f);
  28
  29   f = fopen (tmpfname, "r");
  30   if (!f)
  31     {
  32       perror ("fopen for reading");
  33       remove (tmpfname);
  34       return 1;
  35     }
  36
  37   char buf[12] = "";
  38   if (1 != fscanf (f, "%s", buf))
  39     {
  40       perror ("fscanf");
  41       fclose (f);
  42       remove (tmpfname);
  43       return 1;
  44     }
  45
  46   fclose (f);
  47   remove (tmpfname);
  48
  49   if (strcmp (buf, "123456789"))
  50     abort ();
  51
  52   return 0;
  53 }