gcc/testsuite/gdc.test/compilable/test14838.d

   1 // PERMUTE_ARGS:
   2
   3 struct A(T) { ~this() {} }
   4 class C { A!int[1] array; }
   5
   6 void test14838() pure nothrow @nogc @safe
   7 {
   8     C c;
   9     c.__xdtor();    // C.~this() will also be inferred to
  10                     // pure nothrow @nogc @safe
  11
  12     A!int[1] array;
  13     // scope destructor call does not cause attribute violation.
  14 }
  15
  16 // ----
  17
  18 /*
  19  * This is a reduced test case comes from std.container.Array template,
  20  * to fix the semantic analysis order issue for correct destructor attribute inference.
  21  *
  22  * Before the bugfix:
  23  *   1. StructDeclaration('Array!int').semantic() instantiates
  24  *      RangeT!(Array!int) at the `alias Range = ...;`, but
  25  *      StructDeclaration('RangeT!(Array!int)').semantic() exits
  26  *      with sizeok == SIZEOKfwd, because the size of _outer_ field is not yet determined.
  27  *   2. StructDeclaration('Array!int').semantic() succeeds to determine the size
  28  *      (sizeok = SIZEOKdone).
  29  *   3. StructDeclaration('Array!int').buildOpAssign() will generate opAssign because
  30  *      Array!int._data field has identity opAssign member function.
  31  *   4. The semantic3 will get called for the generated opAssign, then
  32  *         6-1. Array!int.~this() semantic3, and
  33  *         6-2. RefCounted!(Array!int.Payload).~this() semantic3
  34  *      will also get called to infer their attributes.
  35  *   5. In RefCounted!(Array!int.Payload).~this(), destroy(t) will be instantiated.
  36  *      At that, TemplateInstance.expandMembers() will invoke runDeferredSemantic()
  37  *      and it will re-run StructDeclaration('RangeT!(Array!int)').semantic().
  38  *   6. StructDeclaration('RangeT!(Array!int)').semantic() determines the size
  39  *      (sizeok = SIZEOKdone). Then, it will generate identity opAssign and run its semantic3.
  40  *      It will need to infer RangeT!(Array!int).~this() attribute, then it requires the
  41  *      correct attribute of Array!int.~this().
  42  *
  43  *      However, the Array!int.~this() attribute is not yet determined! [bug]
  44  *      -> it's wongly handled as impure/system/throwable/gc-able.
  45  *
  46  *      -> then, the attribute inference results for
  47  *         RangeT!(Array!int).~this() and Array!int.~this() will be incorrect.
  48  *
  49  * After the bugfix:
  50  *   In 6, StructDeclaration('RangeT!(Array!int)').semantic() will check that:
  51  *   all base struct types of the instance fields have completed addition of
  52  *   special functions (dtor, opAssign, etc).
  53  *   If not, it will defer the completion of its semantic pass.
  54  */
  55
  56 void destroy14838(S)(ref S s) if (is(S == struct))
  57 {
  58     s.__xdtor();
  59 }
  60
  61 struct RefCounted14838(T)
  62 {
  63     ~this()
  64     {
  65         T t;
  66         .destroy14838(t);
  67     }
  68
  69     void opAssign(typeof(this) rhs) {}
  70 }
  71
  72 struct RangeT14838(A)
  73 {
  74     A[1] _outer_;
  75 }
  76
  77 struct Array14838(T)
  78 {
  79     struct Payload
  80     {
  81         ~this() {}
  82     }
  83     RefCounted14838!Payload _data;
  84
  85     alias Range = RangeT14838!Array14838;
  86 }
  87
  88 class Test14838
  89 {
  90     Array14838!int[1] field;
  91 }