PR12298 et al: don't recursively instantiate a template specialization from

within the instantiation of that same specialization. This could previously
happen for eagerly-instantiated function templates, variable templates,
exception specifications, default arguments, and a handful of other cases.

We still have an issue here for default template arguments that recursively
make use of themselves and likewise for substitution into the type of a
non-type template parameter, but in those cases we're producing a different
entity each time, so they should instead be caught by the instantiation depth
limit. However, currently we will typically run out of stack before we reach
it. :(


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@280190 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/include/clang/AST/DeclTemplate.h b/include/clang/AST/DeclTemplate.h
index 8671d95c10..2af95c02c4 100644
--- a/include/clang/AST/DeclTemplate.h
+++ b/include/clang/AST/DeclTemplate.h
@@ -43,6 +43,8 @@ class VarTemplatePartialSpecializationDecl;
 typedef llvm::PointerUnion3<TemplateTypeParmDecl*, NonTypeTemplateParmDecl*,
                             TemplateTemplateParmDecl*> TemplateParameter;
 
+NamedDecl *getAsNamedDecl(TemplateParameter P);
+
 /// \brief Stores a list of template parameters for a TemplateDecl and its
 /// derived classes.
 class TemplateParameterList final
@@ -2937,6 +2939,14 @@ public:
   friend class ASTDeclWriter;
 };
 
+inline NamedDecl *getAsNamedDecl(TemplateParameter P) {
+  if (auto *PD = P.dyn_cast<TemplateTypeParmDecl*>())
+    return PD;
+  if (auto *PD = P.dyn_cast<NonTypeTemplateParmDecl*>())
+    return PD;
+  return P.get<TemplateTemplateParmDecl*>();
+}
+
 } /* end of namespace clang */
 
 #endif