Improve the AST representation and semantic analysis for extern

templates. We now distinguish between an explicit instantiation
declaration and an explicit instantiation definition, and know not to
instantiate explicit instantiation declarations. Unfortunately, there
is some remaining confusion w.r.t. instantiation of out-of-line member
function definitions that causes trouble here.
 


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@81053 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 2 deletions

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 807115eb67..b63fc400a5 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -402,6 +402,8 @@ Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
 
 Decl *
 TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
+  // FIXME: Dig out the out-of-line definition of this function template?
+  
   TemplateParameterList *TempParams = D->getTemplateParameters();
   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
   if (!InstParams) 
@@ -496,7 +498,7 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D) {
                            D->getStorageClass(),
                            D->isInline(), D->hasWrittenPrototype());
   Function->setLexicalDeclContext(Owner);
-
+  
   // Attach the parameters
   for (unsigned P = 0; P < Params.size(); ++P)
     Params[P]->setOwningFunction(Function);
@@ -622,7 +624,7 @@ TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
                                                     Method->getDeclName(), 
                                                     TemplateParams, Method);
     if (D->isOutOfLine())
-      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
+      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());    
     Method->setDescribedFunctionTemplate(FunctionTemplate);
   } else if (!FunctionTemplate)
     Method->setInstantiationOfMemberFunction(D);
@@ -979,6 +981,15 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
   if (!Pattern)
     return;
 
+  // C++0x [temp.explicit]p9:
+  //   Except for inline functions, other explicit instantiation declarations
+  //   have the effect of suppressing the implicit instantiation of the entity 
+  //   to which they refer.
+  if (Function->getTemplateSpecializationKind() 
+        == TSK_ExplicitInstantiationDeclaration &&
+      PatternDecl->isOutOfLine() && !PatternDecl->isInline())
+    return;
+  
   InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
   if (Inst)
     return;
@@ -1080,6 +1091,8 @@ void Sema::InstantiateStaticDataMemberDefinition(
     return;
   }
 
+  // FIXME: extern templates
+  
   InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
   if (Inst)
     return;