PR31469: Don't add friend template class decls to redecl chain in dependent contexts.
Fixes a crash in modules where the template class decl becomes the most recent
decl in the redeclaration chain and forcing the template instantiator try to
instantiate the friend declaration, rather than the template definition.
In practice, A::list<int> produces a TemplateSpecializationType
A::__1::list<int, allocator<type-parameter-0-0> >' failing to replace to
subsitute the default argument to allocator<int>.
Kudos Richard Smith (D28399).
llvm-svn: 291753
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 447ed89..7edef70 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -1224,9 +1224,17 @@
}
}
+ // If this is a templated friend in a dependent context we should not put it
+ // on the redecl chain. In some cases, the templated friend can be the most
+ // recent declaration tricking the template instantiator to make substitutions
+ // there.
+ // FIXME: Figure out how to combine with shouldLinkDependentDeclWithPrevious
+ bool ShouldAddRedecl
+ = !(TUK == TUK_Friend && CurContext->isDependentContext());
+
CXXRecordDecl *NewClass =
CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
- PrevClassTemplate?
+ PrevClassTemplate && ShouldAddRedecl ?
PrevClassTemplate->getTemplatedDecl() : nullptr,
/*DelayTypeCreation=*/true);
SetNestedNameSpecifier(NewClass, SS);
@@ -1245,7 +1253,11 @@
ClassTemplateDecl *NewTemplate
= ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
DeclarationName(Name), TemplateParams,
- NewClass, PrevClassTemplate);
+ NewClass);
+
+ if (ShouldAddRedecl)
+ NewTemplate->setPreviousDecl(PrevClassTemplate);
+
NewClass->setDescribedClassTemplate(NewTemplate);
if (ModulePrivateLoc.isValid())
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 7042400..48d8b94 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1219,8 +1219,10 @@
ClassTemplateDecl *Inst
= ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
- D->getIdentifier(), InstParams, RecordInst,
- PrevClassTemplate);
+ D->getIdentifier(), InstParams, RecordInst);
+ assert(!(isFriend && Owner->isDependentContext()));
+ Inst->setPreviousDecl(PrevClassTemplate);
+
RecordInst->setDescribedClassTemplate(Inst);
if (isFriend) {