1  /* PR tree-optimization/90879 - fold zero-equality of strcmp between
       2     a longer string and a smaller array
       3     { dg-do compile }
       4     { dg-options "-O2 -Wall -Wno-string-compare -fdump-tree-optimized -ftrack-macro-expansion=0" } */
       5  
       6  #include "strlenopt.h"
       7  
       8  #define A(expr)                                                 \
       9    ((expr)                                                       \
      10     ? (void)0                                                    \
      11     : (__builtin_printf ("assertion failed on line %i: %s\n",    \
      12                          __LINE__, #expr),                       \
      13        __builtin_abort ()))
      14  
      15  void clobber (void*, ...);
      16  
      17  struct S { char a4[4], c; };
      18  
      19  extern char a4[4];
      20  extern char b4[4];
      21  
      22  /* Verify that comparison of string literals with arrays with unknown
      23     content but size that prevents them from comparing equal is folded
      24     to a constant.  */
      25  
      26  void test_array_lit (void)
      27  {
      28    A (strcmp (a4, "1234")); clobber (a4);
      29    A (strcmp (a4, "12345")); clobber (a4);
      30    A (strcmp (a4, "123456")); clobber (a4);
      31    A (strcmp ("1234", a4)); clobber (a4);
      32    A (strcmp ("12345", a4)); clobber (a4);
      33    A (strcmp ("123456", a4)); clobber (a4);
      34  }
      35  
      36  void test_memarray_lit (struct S *p)
      37  {
      38  #if 0
      39    /* Member arrays not handled due to the fix for PR 92765.  */
      40    A (strcmp (p->a4, "1234"));
      41    A (strcmp (p->a4, "12345"));
      42    A (strcmp (p->a4, "123456"));
      43  
      44    A (strcmp ("1234", p->a4));
      45    A (strcmp ("12345", p->a4));
      46    A (strcmp ("123456", p->a4));
      47  #endif
      48  }
      49  
      50  /* Verify that the equality of empty strings is folded.  */
      51  
      52  void test_empty_string (void)
      53  {
      54    A (0 == strcmp ("", ""));
      55  
      56    *a4 = '\0';
      57    A (0 == strcmp (a4, ""));
      58    A (0 == strcmp ("", a4));
      59    A (0 == strcmp (a4, a4));
      60  
      61    char s[8] = "";
      62    A (0 == strcmp (a4, s));
      63  
      64    a4[1] = '\0';
      65    b4[1] = '\0';
      66    A (0 == strcmp (a4 + 1, b4 + 1));
      67  
      68    a4[2] = '\0';
      69    b4[2] = '\0';
      70    A (0 == strcmp (&a4[2], &b4[2]));
      71  
      72  #if 0
      73    /* The following isn't handled yet due to PR 92155.  */
      74    clobber (a4, b4);
      75  
      76    memset (a4, 0, sizeof a4);
      77    memset (b4, 0, sizeof b4);
      78    A (0 == strcmp (a4, b4));
      79  #endif
      80  }
      81  
      82  /* Verify that comparison of dynamically created strings with unknown
      83     arrays is folded.  */
      84  
      85  void test_array_copy (void)
      86  {
      87    char s[8];
      88    strcpy (s, "1234");
      89    A (strcmp (a4, s));
      90  
      91    strcpy (s, "12345");
      92    A (strlen (s) == 5);
      93    A (strcmp (a4, s)); clobber (a4);
      94  
      95    strcpy (s, "123456");
      96    A (strcmp (a4, s)); clobber (a4);
      97  
      98    strcpy (s, "1234");
      99    A (strcmp (s, a4)); clobber (a4);
     100  
     101    strcpy (s, "12345");
     102    A (strcmp (s, a4)); clobber (a4);
     103  
     104    strcpy (s, "123456");
     105    A (strcmp (s, a4)); clobber (a4);
     106  }
     107  
     108  
     109  void test_array_bounded (void)
     110  {
     111    A (strncmp (a4, "12345", 5)); clobber (a4);
     112    A (strncmp ("54321", a4, 5)); clobber (a4);
     113  
     114    A (strncmp (a4, "123456", 5)); clobber (a4);
     115    A (strncmp ("654321", a4, 5)); clobber (a4);
     116  }
     117  
     118  void test_array_copy_bounded (void)
     119  {
     120    char s[8];
     121    strcpy (s, "12345");
     122    A (strncmp (a4, s, 5)); clobber (a4);
     123    strcpy (s, "54321");
     124    A (strncmp (s, a4, 5)); clobber (a4);
     125  
     126    strcpy (s, "123456");
     127    A (strncmp (a4, s, 5)); clobber (a4);
     128    strcpy (s, "654321");
     129    A (strncmp (s, a4, 5)); clobber (a4);
     130  }
     131  
     132  /* { dg-final { scan-tree-dump-not "abort|strcmp|strncmp" "optimized" } } */