gcc/testsuite/gcc.dg/strlenopt-93.c

   1 /* Verify that strlen doesn't (inadvertently) use the size of an array
   2    of char pointers to put an upper bound on the length of the strings
   3    they point to.
   4    { dg-do compile }
   5    { dg-options "-O2 -Wall -fdump-tree-optimized" } */
   6
   7 void eaa_test (void)
   8 {
   9   extern char eaa[4][4];
  10
  11   char (*p)[4] = eaa;
  12
  13   if (!*p)
  14     return;
  15
  16   /* The longest string stored in EAA is 15 characters.  */
  17   if (__builtin_strlen (*p) > 14)
  18     {
  19       extern void eaa_ok (void);
  20       eaa_ok ();
  21     }
  22
  23   if (__builtin_strlen (*p) > 15)
  24     {
  25       extern void eaa_fail (void);
  26       eaa_fail ();
  27     }
  28 }
  29
  30 /* { dg-final { scan-tree-dump-times "eaa_ok" 1 "optimized" } }
  31    { dg-final { scan-tree-dump-not "eaa_fail" "optimized" } } */
  32
  33
  34 void epa_test (void)
  35 {
  36   extern char* epa[4];
  37   char **p = epa;
  38
  39   if (*p && __builtin_strlen (*p) > 123)
  40     {
  41       extern void epa_ok (void);
  42       epa_ok ();
  43     }
  44 }
  45
  46 /* { dg-final { scan-tree-dump-times "epa_ok" 1 "optimized" } } */
  47
  48
  49 static char* spa[4];
  50
  51 void spa_test (void)
  52 {
  53   char **p = spa;
  54
  55   if (*p && __builtin_strlen (*p) > 123)
  56     {
  57       extern void spa_ok ();
  58       spa_ok ();
  59     }
  60 }
  61
  62 /* { dg-final { scan-tree-dump-times "spa_ok" 1 "optimized" } } */
  63
  64
  65 void sink (void*, ...);
  66
  67 void init (void)
  68 {
  69   /* Make believe even the static array SA may be non-zero.  */
  70   sink (spa);
  71 }