clang/test/CodeGenCXX/debug-info-template-fwd.cpp

   1 // RUN: %clang_cc1 %s -triple=x86_64-apple-darwin -debug-info-kind=limited -emit-llvm -o - | FileCheck %s
   2 // This test is for a crash when emitting debug info for not-yet-completed
   3 // types.
   4 // Test that we don't actually emit a forward decl for the offending class:
   5 // CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "Derived<int>"
   6 // CHECK-NOT:              DIFlagFwdDecl
   7 // CHECK-SAME:             ){{$}}
   8 template <class A> class Derived;
   9
  10 template <class A> class Base {
  11   static Derived<A> *create();
  12 };
  13
  14 template <class A> struct Derived : Base<A> {
  15 };
  16
  17 Base<int> *f;
  18
  19 // During the instantiation of Derived<int>, Base<int> becomes required to be
  20 // complete - since the declaration has already been emitted (due to 'f',
  21 // above), we immediately try to build debug info for Base<int> which then
  22 // requires the (incomplete definition) of Derived<int> which is problematic.
  23 //
  24 // (if 'f' is not present, the point at which Base<int> becomes required to be
  25 // complete during the instantiation of Derived<int> is a no-op because
  26 // Base<int> was never emitted so we ignore it and carry on until we
  27 // wire up the base class of Derived<int> in the debug info later on)
  28 Derived<int> d;