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.
 

llvm-svn: 81053

1 files changed, 21 insertions, 17 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 0c47e996c8e..55e81aecbc7 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -623,8 +623,7 @@ Sema::SubstBaseSpecifiers(CXXRecordDecl *Instantiation,
 /// \param TemplateArgs The template arguments to be substituted into
 /// the pattern.
 ///
-/// \param ExplicitInstantiation whether this is an explicit instantiation
-/// (otherwise, it is an implicit instantiation).
+/// \param TSK the kind of implicit or explicit instantiation to perform.
 ///
 /// \param Complain whether to complain if the class cannot be instantiated due
 /// to the lack of a definition.
@@ -634,7 +633,7 @@ bool
 Sema::InstantiateClass(SourceLocation PointOfInstantiation,
                        CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern,
                        const MultiLevelTemplateArgumentList &TemplateArgs,
-                       bool ExplicitInstantiation,
+                       TemplateSpecializationKind TSK,
                        bool Complain) {
   bool Invalid = false;
 
@@ -650,7 +649,7 @@ Sema::InstantiateClass(SourceLocation PointOfInstantiation,
       Diag(Pattern->getLocation(), diag::note_member_of_template_here);
     } else {
       Diag(PointOfInstantiation, diag::err_template_instantiate_undefined)
-        << ExplicitInstantiation
+        << (TSK != TSK_ImplicitInstantiation)
         << Context.getTypeDeclType(Instantiation);
       Diag(Pattern->getLocation(), diag::note_template_decl_here);
     }
@@ -708,9 +707,10 @@ Sema::InstantiateClass(SourceLocation PointOfInstantiation,
     Consumer.HandleTagDeclDefinition(Instantiation);
 
   // If this is an explicit instantiation, instantiate our members, too.
-  if (!Invalid && ExplicitInstantiation) {
+  if (!Invalid && TSK != TSK_ImplicitInstantiation) {
     Inst.Clear();
-    InstantiateClassMembers(PointOfInstantiation, Instantiation, TemplateArgs);
+    InstantiateClassMembers(PointOfInstantiation, Instantiation, TemplateArgs,
+                            TSK);
   }
 
   return Invalid;
@@ -719,7 +719,7 @@ Sema::InstantiateClass(SourceLocation PointOfInstantiation,
 bool 
 Sema::InstantiateClassTemplateSpecialization(
                            ClassTemplateSpecializationDecl *ClassTemplateSpec,
-                           bool ExplicitInstantiation,
+                           TemplateSpecializationKind TSK,
                            bool Complain) {
   // Perform the actual instantiation on the canonical declaration.
   ClassTemplateSpec = cast<ClassTemplateSpecializationDecl>(
@@ -798,14 +798,12 @@ Sema::InstantiateClassTemplateSpecialization(
   }
 
   // Note that this is an instantiation.
-  ClassTemplateSpec->setSpecializationKind(
-                        ExplicitInstantiation? TSK_ExplicitInstantiation 
-                                             : TSK_ImplicitInstantiation);
+  ClassTemplateSpec->setSpecializationKind(TSK);
 
   bool Result = InstantiateClass(ClassTemplateSpec->getLocation(),
                                  ClassTemplateSpec, Pattern, 
                               getTemplateInstantiationArgs(ClassTemplateSpec),
-                                 ExplicitInstantiation,
+                                 TSK,
                                  Complain);
   
   for (unsigned I = 0, N = Matched.size(); I != N; ++I) {
@@ -822,8 +820,10 @@ Sema::InstantiateClassTemplateSpecialization(
 /// or a member class of a template.
 void
 Sema::InstantiateClassMembers(SourceLocation PointOfInstantiation,
-                        CXXRecordDecl *Instantiation,
-                        const MultiLevelTemplateArgumentList &TemplateArgs) {
+                              CXXRecordDecl *Instantiation,
+                        const MultiLevelTemplateArgumentList &TemplateArgs,
+                              TemplateSpecializationKind TSK) {
+  // FIXME: extern templates
   for (DeclContext::decl_iterator D = Instantiation->decls_begin(),
                                DEnd = Instantiation->decls_end();
        D != DEnd; ++D) {
@@ -839,7 +839,8 @@ Sema::InstantiateClassMembers(SourceLocation PointOfInstantiation,
                "Missing instantiated-from-template information");
         InstantiateClass(PointOfInstantiation, Record,
                          Record->getInstantiatedFromMemberClass(),
-                         TemplateArgs, true);
+                         TemplateArgs,
+                         TSK);
       }
     }
   }
@@ -848,9 +849,11 @@ Sema::InstantiateClassMembers(SourceLocation PointOfInstantiation,
 /// \brief Instantiate the definitions of all of the members of the
 /// given class template specialization, which was named as part of an
 /// explicit instantiation.
-void Sema::InstantiateClassTemplateSpecializationMembers(
+void 
+Sema::InstantiateClassTemplateSpecializationMembers(
                                            SourceLocation PointOfInstantiation,
-                          ClassTemplateSpecializationDecl *ClassTemplateSpec) {
+                            ClassTemplateSpecializationDecl *ClassTemplateSpec,
+                                               TemplateSpecializationKind TSK) {
   // C++0x [temp.explicit]p7:
   //   An explicit instantiation that names a class template
   //   specialization is an explicit instantion of the same kind
@@ -860,7 +863,8 @@ void Sema::InstantiateClassTemplateSpecializationMembers(
   //   containing the explicit instantiation, except as described
   //   below.
   InstantiateClassMembers(PointOfInstantiation, ClassTemplateSpec,
-                          getTemplateInstantiationArgs(ClassTemplateSpec));
+                          getTemplateInstantiationArgs(ClassTemplateSpec),
+                          TSK);
 }
 
 Sema::OwningStmtResult