gcc/testsuite/gcc.dg/Warray-bounds-84.c

   1 /* PR tree-optimization/101397 - spurious warning writing to the result
   2    of stpcpy minus 1
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall" } */
   5
   6 char* strcpy (char*, const char*);
   7
   8 void sink (int, ...);
   9
  10 extern char ax[], a3[3], a5[5], *s;
  11
  12 volatile int x;
  13
  14 void test_strcpy (int i)
  15 {
  16   {
  17     char *p = strcpy (ax, s);
  18     x = p[-1];                          // { dg-warning "\\\[-Warray-bounds" }
  19     x = p[ 0];
  20     x = p[+9];
  21   }
  22
  23   {
  24     char *p = strcpy (a3, s);
  25     x = p[-1];                          // { dg-warning "\\\[-Warray-bounds" }
  26     x = p[0];
  27     x = p[1];
  28     x = p[2];
  29     x = p[3];                           // { dg-warning "\\\[-Warray-bounds" }
  30  }
  31
  32   {
  33     char *p = strcpy (a5, s);
  34     x = p[-1];                          // { dg-warning "\\\[-Warray-bounds" }
  35     sink (p[0], p[1], p[2], p[3], p[4]);
  36     x = p[ 5];                          // { dg-warning "\\\[-Warray-bounds" }
  37   }
  38
  39   {
  40     char *p = strcpy (a5 + 1, s);
  41     x = p[-2];                          // { dg-warning "\\\[-Warray-bounds" }
  42     sink (p[-1], p[0], p[1], p[2], p[3]);
  43     x = p[4];                           // { dg-warning "\\\[-Warray-bounds" }
  44   }
  45
  46   {
  47     char *p = strcpy (a5 + 2, s);
  48     x = p[-3];                          // { dg-warning "\\\[-Warray-bounds" }
  49     sink (p[-2], p[-1], p[0], p[1], p[2]);
  50     x = p[3];                           // { dg-warning "\\\[-Warray-bounds" }
  51   }
  52
  53   {
  54     char *p = strcpy (a5 + 3, s);
  55     x = p[-4];                          // { dg-warning "\\\[-Warray-bounds" }
  56     sink (p[-3], p[-2], p[-1], p[0], p[1]);
  57     x = p[2];                           // { dg-warning "\\\[-Warray-bounds" }
  58   }
  59
  60   {
  61     char *p = strcpy (ax, a3);
  62     p[-1] = 1;                          // { dg-warning "\\\[-Warray-bounds" }
  63     sink (p[0], p[1], p[2], p[9], p[99]);
  64   }
  65 }