gcc/testsuite/gcc.dg/pr19633-1.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O2" } */
   3
   4 extern void abort (void);
   5
   6 struct S
   7 {
   8   int w, x, y, z;
   9 };
  10
  11 struct T
  12 {
  13   int r;
  14   struct S s;
  15 };
  16
  17 struct S bar (struct S x, struct S *y)
  18 {
  19   y->w = 4;
  20   return *y;
  21 }
  22
  23 void
  24 foo (int a, struct T b)
  25 {
  26   struct S x;
  27   struct S *c = &x;
  28   if (a)
  29     c = &b.s;
  30   b.s.w = 3;
  31   /* This call should be marked as clobbering 'x' and 'b'.  */
  32   *c = bar (*c, c);
  33   if (b.s.w == 3)
  34     abort ();
  35 }
  36
  37 float Y;
  38
  39 struct S bar1 (struct S x, struct S y)
  40 {
  41   Y = 4;
  42   return x;
  43 }
  44
  45 void
  46 foo1 (int a, struct T b)
  47 {
  48   struct S x;
  49   struct S *c = &x;
  50   float z, *k = &z;
  51   if (a)
  52     c = &b.s;
  53   b.s.w = 3;
  54   /* This call should NOT be marked as clobbering 'x' and 'b'.  */
  55   x = bar1 (*c, *c);
  56   if (b.s.w != 3)
  57     link_error ();
  58 }
  59
  60 int main ()
  61 {
  62   struct T b;
  63   foo (3, b);
  64   foo1 (3, b);
  65   return 0;
  66 }