Instantiate function declarations in instantiated functions.

If a function declaration is found inside a template function as in:

    template<class T> void f() {
      void g(int x = T::v) except(T::w);
    }

it must be instantiated along with the enclosing template function,
including default arguments and exception specification.

Together with the patch committed in r240974 this implements DR1484.

Differential Revision: http://reviews.llvm.org/D11194

llvm-svn: 245810

3 files changed, 17 insertions, 11 deletions

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 40b135f9202..00d7d323b72 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -266,6 +266,18 @@ void Decl::setDeclContextsImpl(DeclContext *SemaDC, DeclContext *LexicalDC,
   }
 }
 
+bool Decl::isLexicallyWithinFunctionOrMethod() const {
+  const DeclContext *LDC = getLexicalDeclContext();
+  do {
+    if (LDC->isFunctionOrMethod())
+      return true;
+    if (!isa<TagDecl>(LDC))
+      return false;
+    LDC = LDC->getParent();
+  } while (LDC);
+  return false;
+}
+
 bool Decl::isInAnonymousNamespace() const {
   const DeclContext *DC = getDeclContext();
   do {
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 12cbd5bd4f1..031a2bad5f5 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1682,11 +1682,10 @@ ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
     UnparsedDefaultArgInstantiations[OldParm].push_back(NewParm);
   } else if (Expr *Arg = OldParm->getDefaultArg()) {
     FunctionDecl *OwningFunc = cast<FunctionDecl>(OldParm->getDeclContext());
-    CXXRecordDecl *ClassD = dyn_cast<CXXRecordDecl>(OwningFunc->getDeclContext());
-    if (ClassD && ClassD->isLocalClass() && !ClassD->isLambda()) {
-      // If this is a method of a local class, as per DR1484 its default
-      // arguments must be instantiated.
-      Sema::ContextRAII SavedContext(*this, ClassD);
+    if (OwningFunc->isLexicallyWithinFunctionOrMethod()) {
+      // Instantiate default arguments for methods of local classes (DR1484)
+      // and non-defining declarations.
+      Sema::ContextRAII SavedContext(*this, OwningFunc);
       LocalInstantiationScope Local(*this);
       ExprResult NewArg = SubstExpr(Arg, TemplateArgs);
       if (NewArg.isUsable())
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index c8a067658bf..9899f1e8b1a 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3247,16 +3247,11 @@ TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
     // exception specification.
     // DR1484: Local classes and their members are instantiated along with the
     // containing function.
-    bool RequireInstantiation = false;
-    if (CXXRecordDecl *Cls = dyn_cast<CXXRecordDecl>(Tmpl->getDeclContext())) {
-      if (Cls->isLocalClass())
-        RequireInstantiation = true;
-    }
     if (SemaRef.getLangOpts().CPlusPlus11 &&
         EPI.ExceptionSpec.Type != EST_None &&
         EPI.ExceptionSpec.Type != EST_DynamicNone &&
         EPI.ExceptionSpec.Type != EST_BasicNoexcept &&
-        !RequireInstantiation) {
+        !Tmpl->isLexicallyWithinFunctionOrMethod()) {
       FunctionDecl *ExceptionSpecTemplate = Tmpl;
       if (EPI.ExceptionSpec.Type == EST_Uninstantiated)
         ExceptionSpecTemplate = EPI.ExceptionSpec.SourceTemplate;