gcc/testsuite/gcc.dg/strlenopt-57.c

   1 /* PR tree-optimization/86914 - wrong code with strlen() of poor-man's
   2    flexible array member plus offset
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall -fdump-tree-optimized" } */
   5
   6 #include "strlenopt.h"
   7
   8 struct A0 { char i, a[0]; };
   9 struct A1 { char i, a[1]; };
  10 struct A9 { char i, a[9]; };
  11 struct Ax { char i, a[]; };
  12
  13 extern int a[];
  14
  15 extern struct A0 a0;
  16 extern struct A1 a1;
  17 extern struct A9 a9;
  18 extern struct Ax ax;
  19
  20 void test_var_flexarray_cst_off (void)
  21 {
  22   /* Use arbitrary constants greater than 16 in case GCC ever starts
  23      unrolling strlen() calls with small array arguments.  */
  24   a[0] = 17 < strlen (a0.a + 1);        // { dg-warning "\\\[-Warray-bounds|-Wstringop-overread" }
  25   a[1] = 19 < strlen (a1.a + 1);        // { dg-warning "\\\[-Wstringop-overread" }
  26   a[2] = 23 < strlen (a9.a + 9);        // { dg-warning "\\\[-Wstringop-overread" }
  27   a[3] = 29 < strlen (ax.a + 3);
  28 }
  29
  30 void test_ptr_flexarray_cst_off (struct A0 *p0, struct A1 *p1,
  31                                  struct A9 *p9, struct Ax *px)
  32 {
  33   a[0] = 17 < strlen (p0->a + 1);
  34   a[1] = 19 < strlen (p1->a + 1);
  35   a[2] = 23 < strlen (p9->a + 9);
  36   a[3] = 29 < strlen (px->a + 3);
  37 }
  38
  39 void test_ptr_flexarray_var_off (struct A0 *p0, struct A1 *p1,
  40                                  struct A9 *p9, struct Ax *px,
  41                                  int i)
  42 {
  43   a[0] = 17 < strlen (p0->a + i);
  44   a[1] = 19 < strlen (p1->a + i);
  45   a[2] = 23 < strlen (p9->a + i);
  46   a[3] = 29 < strlen (px->a + i);
  47 }
  48
  49 /* { dg-final { scan-tree-dump-times "strlen" 12 "optimized" } } */