gcc/testsuite/gcc.dg/builtin-strncat-chk-1.c

   1 /* Test whether buffer overflow warnings for __strncat_chk builtin
   2    are emitted properly.  */
   3 /* { dg-do compile } */
   4 /* { dg-options "-O2 -std=gnu99 -ftrack-macro-expansion=0" } */
   5
   6 extern void abort (void);
   7
   8 #include "../gcc.c-torture/execute/builtins/chk.h"
   9
  10 char buf1[20];
  11 char *q;
  12
  13 void
  14 test (int arg, ...)
  15 {
  16   char *p = &buf1[10];
  17
  18   *p = 0;
  19   strncat (p, "abcdefg", 9);
  20   *p = 0;
  21   strncat (p, "abcdefghi", 9);
  22   *p = 0;
  23   strncat (p, "abcdefghij", 9);
  24   *p = 0;
  25   strncat (p, "abcdefghi", 10);
  26   *p = 0;
  27   strncat (p, "abcdefghij", 10); /* { dg-warning "will always overflow" } */
  28   *p = 0;
  29   strncat (p, "abcdefgh", 11);
  30   *p = 0;
  31   strncat (p, "abcdefghijkl", 11); /* { dg-warning "will always overflow" } */
  32   *p = 0;
  33   strncat (p, q, 9);
  34   *p = 0;
  35   strncat (p, q, 10); /* { dg-warning "might overflow" } */
  36   *p = 0;
  37   strncat (p, q, 11); /* { dg-warning "might overflow" } */
  38 }