gcc/testsuite/gdc.test/runnable/test13613.d

   1 // PERMUTE_ARGS:
   2
   3 // MT!"y" is analyzed from the pragma inside MT!"x"
   4 /*
   5 TEST_OUTPUT:
   6 ---
   7 CT x.offsetof = <
   8 CT y.offsetof = <
   9 0 > y
  10 0 > x
  11 ---
  12 */
  13
  14 mixin template MT(string id)
  15 {
  16     union
  17     {
  18         mixin("void* " ~ id ~ ";");
  19     }
  20
  21     // Evaluating `typeof(this).init` completes data layout.
  22     pragma(msg,
  23         "CT " ~ id ~ ".offsetof = <\n",
  24         cast(int)typeof(this).init.i.offsetof, " > " ~ id);
  25 }
  26
  27 struct S1
  28 {
  29     int i;
  30     mixin MT!"x";
  31     mixin MT!"y";
  32 }
  33 struct S2
  34 {
  35     int i;
  36     union { void* x; }
  37     union { void* y; }
  38 }
  39 struct S3
  40 {
  41     int i;
  42     void* x;
  43     void* y;
  44 }
  45
  46 void main()
  47 {
  48     // S1, S2, and S3 should have exactly same data layout.
  49     static assert(S1.i.offsetof == S3.i.offsetof);
  50     static assert(S1.i.offsetof == S3.i.offsetof);
  51     static assert(S1.x.offsetof == S3.x.offsetof);
  52     static assert(S1.y.offsetof == S3.y.offsetof);
  53     static assert(S2.x.offsetof == S3.x.offsetof);
  54     static assert(S2.y.offsetof == S3.y.offsetof);
  55     static assert(S1.sizeof == S3.sizeof);
  56     static assert(S2.sizeof == S3.sizeof);
  57
  58     S1 s = void;
  59
  60     s.i = 1;
  61     assert(s.i == 1);
  62     s.x = null;
  63     assert(s.i == 1);
  64     s.y = null;
  65     assert(s.i == 1);
  66
  67     char a, b;
  68     s.x = cast(void*)&a;
  69     assert(s.x is &a);
  70     assert(s.y is null);
  71     s.y = cast(void*)&b;
  72     assert(s.x is &a);
  73     assert(s.y is &b);
  74 }