gcc/testsuite/gcc.dg/Wstringop-overflow-65.c

   1 /* PR middle-end/96963 - -Wstringop-overflow false positive with
   2    -ftree-vectorize when assigning consecutive char struct members
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall -ftree-vectorize" } */
   5
   6 void sink (void*);
   7
   8 struct Char
   9 {
  10   int i;
  11   char c, d, e, f;
  12   char a[2], b[2];
  13 };
  14
  15 void nowarn_char_assign (struct Char *p)
  16 {
  17   sink (&p->c);
  18
  19   /* Verify the bogus warning triggered by the tree-ssa-strlen.c pass
  20      is not issued.  */
  21   p->c = 1;         // { dg-bogus "\\\[-Wstringop-overflow" }
  22   p->d = 2;
  23   p->e = 3;
  24   p->f = 4;
  25 }
  26
  27 void nowarn_char_array_assign (struct Char *p)
  28 {
  29   sink (p->a);
  30
  31   p->a[0] = 1;      // { dg-bogus "\\\[-Wstringop-overflow" }
  32   p->a[1] = 2;
  33   p->b[0] = 3;
  34   p->b[1] = 4;
  35 }
  36
  37 void warn_char_array_assign_interior (struct Char *p)
  38 {
  39   sink (p->a);
  40
  41   p->a[0] = 1;
  42   p->a[1] = 2;
  43 #pragma GCC diagnostic push
  44 #pragma GCC diagnostic ignored "-Warray-bounds"
  45   /* Warnings are only suppressed for trailing arrays.  Verify
  46      one is issued for an interior array.  */
  47   p->a[2] = 5;      // { dg-warning "\\\[-Wstringop-overflow" }
  48 #pragma GCC diagnostic pop
  49 }
  50
  51 void warn_char_array_assign_trailing (struct Char *p)
  52 {
  53   /* This is separated from warn_char_array_assign_interior because
  54      otherwise GCC removes the store to p->a[2] as dead since it's
  55      overwritten by p->b[0].  */
  56   sink (p->b);
  57
  58   p->b[0] = 3;
  59   p->b[1] = 4;
  60 #pragma GCC diagnostic push
  61 #pragma GCC diagnostic ignored "-Warray-bounds"
  62   /* Warnings are only suppressed for trailing arrays with at most
  63      one element.  Verify one is issued for a two-element array.  */
  64   p->b[2] = 5;      // { dg-warning "\\\[-Wstringop-overflow" }
  65 #pragma GCC diagnostic pop
  66 }
  67
  68
  69 /* Also verify there's no warning for other types than char (even though
  70    the problem was limited to chars and -Wstringop-overflow should only
  71    trigger for character accesses).  */
  72
  73 struct Short
  74 {
  75   int i;
  76   short c, d, e, f;
  77   short a[2], b[2];
  78 };
  79
  80 void nowarn_short_assign (struct Short *p)
  81 {
  82   sink (&p->c);
  83
  84   p->c = 1;
  85   p->d = 2;
  86   p->e = 3;
  87   p->f = 4;
  88 }
  89
  90 void nowarn_short_array_assign (struct Short *p)
  91 {
  92   sink (p->a);
  93
  94   p->a[0] = 1;
  95   p->a[1] = 2;
  96   p->b[0] = 3;
  97   p->b[1] = 4;
  98 }