[llvm up]

A template name can refer to a set of overloaded function
templates. Model this in TemplateName, which can now refer to an
OverloadedFunctionDecl that contains function templates. This removes
an unspeakable hack in Sema::isTemplateName.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77488 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 73 insertions, 12 deletions

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index f3a417181e..cda55e2202 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -2036,6 +2036,12 @@ TemplateName ASTContext::getCanonicalTemplateName(TemplateName Name) {
   if (TemplateDecl *Template = Name.getAsTemplateDecl())
     return TemplateName(cast<TemplateDecl>(Template->getCanonicalDecl()));
 
+  // If this template name refers to a set of overloaded function templates, 
+  /// the canonical template name merely stores the set of function templates.
+  if (OverloadedFunctionDecl *Ovl = Name.getAsOverloadedFunctionDecl())
+    // FIXME: Can't really canonicalize a set of overloaded functions, can we?
+    return TemplateName(Ovl);
+  
   DependentTemplateName *DTN = Name.getAsDependentTemplateName();
   assert(DTN && "Non-dependent template names must refer to template decls.");
   return DTN->CanonicalTemplateName;
@@ -3052,6 +3058,25 @@ TemplateName ASTContext::getQualifiedTemplateName(NestedNameSpecifier *NNS,
   return TemplateName(QTN);
 }
 
+/// \brief Retrieve the template name that represents a qualified
+/// template name such as \c std::vector.
+TemplateName ASTContext::getQualifiedTemplateName(NestedNameSpecifier *NNS, 
+                                                  bool TemplateKeyword,
+                                            OverloadedFunctionDecl *Template) {
+  llvm::FoldingSetNodeID ID;
+  QualifiedTemplateName::Profile(ID, NNS, TemplateKeyword, Template);
+  
+  void *InsertPos = 0;
+  QualifiedTemplateName *QTN =
+  QualifiedTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
+  if (!QTN) {
+    QTN = new (*this,4) QualifiedTemplateName(NNS, TemplateKeyword, Template);
+    QualifiedTemplateNames.InsertNode(QTN, InsertPos);
+  }
+  
+  return TemplateName(QTN);
+}
+
 /// \brief Retrieve the template name that represents a dependent
 /// template name such as \c MetaFun::template apply.
 TemplateName ASTContext::getDependentTemplateName(NestedNameSpecifier *NNS, 
diff --git a/lib/AST/TemplateName.cpp b/lib/AST/TemplateName.cpp
index 5b671c111f..3913121b09 100644
--- a/lib/AST/TemplateName.cpp
+++ b/lib/AST/TemplateName.cpp
@@ -29,14 +29,26 @@ TemplateDecl *TemplateName::getAsTemplateDecl() const {
   return 0;
 }
 
+OverloadedFunctionDecl *TemplateName::getAsOverloadedFunctionDecl() const {
+  if (OverloadedFunctionDecl *Ovl 
+        = Storage.dyn_cast<OverloadedFunctionDecl *>())
+    return Ovl;
+  
+  if (QualifiedTemplateName *QTN = getAsQualifiedTemplateName())
+    return QTN->getOverloadedFunctionDecl();
+  
+  return 0;
+}
+
 bool TemplateName::isDependent() const {
   if (TemplateDecl *Template = getAsTemplateDecl()) {
-    // FIXME: We don't yet have a notion of dependent
-    // declarations. When we do, check that. This hack won't last
-    // long!.
-    return isa<TemplateTemplateParmDecl>(Template);
+    return isa<TemplateTemplateParmDecl>(Template) || 
+      Template->getDeclContext()->isDependentContext();
   }
 
+  if (OverloadedFunctionDecl *Ovl = getAsOverloadedFunctionDecl())
+    return Ovl->getDeclContext()->isDependentContext();
+  
   return true;
 }
 
@@ -45,16 +57,20 @@ TemplateName::print(llvm::raw_ostream &OS, const PrintingPolicy &Policy,
                     bool SuppressNNS) const {
   if (TemplateDecl *Template = Storage.dyn_cast<TemplateDecl *>())
     OS << Template->getIdentifier()->getName();
+  else if (OverloadedFunctionDecl *Ovl 
+             = Storage.dyn_cast<OverloadedFunctionDecl *>())
+    OS << Ovl->getNameAsString();
   else if (QualifiedTemplateName *QTN = getAsQualifiedTemplateName()) {
     if (!SuppressNNS)
       QTN->getQualifier()->print(OS, Policy);
     if (QTN->hasTemplateKeyword())
       OS << "template ";
-    OS << QTN->getTemplateDecl()->getIdentifier()->getName();
+    OS << QTN->getDecl()->getNameAsString();
   } else if (DependentTemplateName *DTN = getAsDependentTemplateName()) {
     if (!SuppressNNS)
       DTN->getQualifier()->print(OS, Policy);
     OS << "template ";
+    // FIXME: Shouldn't we have a more general kind of name?
     OS << DTN->getName()->getName();
   }
 }
@@ -65,3 +81,13 @@ void TemplateName::dump() const {
   LO.Bool = true;
   print(llvm::errs(), PrintingPolicy(LO));
 }
+
+TemplateDecl *QualifiedTemplateName::getTemplateDecl() const { 
+  return dyn_cast<TemplateDecl>(Template); 
+}
+
+OverloadedFunctionDecl *
+QualifiedTemplateName::getOverloadedFunctionDecl() const {
+  return dyn_cast<OverloadedFunctionDecl>(Template); 
+}
+
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index dd5bfc4e88..f9abb3dbd9 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -2701,6 +2701,8 @@ Sema::ActOnCallExpr(Scope *S, ExprArg fn, SourceLocation LParenLoc,
     } else if (TemplateIdRefExpr *TemplateIdRef 
                  = dyn_cast<TemplateIdRefExpr>(FnExpr)) {
       NDecl = TemplateIdRef->getTemplateName().getAsTemplateDecl();
+      if (!NDecl)
+        NDecl = TemplateIdRef->getTemplateName().getAsOverloadedFunctionDecl();
       HasExplicitTemplateArgs = true;
       ExplicitTemplateArgs = TemplateIdRef->getTemplateArgs();
       NumExplicitTemplateArgs = TemplateIdRef->getNumTemplateArgs();
diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 57656ce8af..9f1ea4efd7 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -1596,8 +1596,7 @@ Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs,
     if (DRE)
       Ovl = dyn_cast<OverloadedFunctionDecl>(DRE->getDecl());
     else if (TIRE)
-      Ovl = dyn_cast_or_null<OverloadedFunctionDecl>(
-                                  TIRE->getTemplateName().getAsTemplateDecl());
+      Ovl = TIRE->getTemplateName().getAsOverloadedFunctionDecl();
     if (!Ovl)
       continue;
 
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 0300093fa4..245ba3f8f2 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -93,10 +93,18 @@ TemplateNameKind Sema::isTemplateName(const IdentifierInfo &II, Scope *S,
               if (isa<FunctionTemplateDecl>(*F))
                 OvlTemplate->addOverload(*F);
             }
-            
-            // FIXME: HACK! We need TemplateName to be able to refer to
-            // sets of overloaded function templates.
-            TemplateResult = TemplateTy::make(OvlTemplate);
+
+            // Form the resulting TemplateName
+            if (SS && SS->isSet() && !SS->isInvalid()) {
+              NestedNameSpecifier *Qualifier 
+                = static_cast<NestedNameSpecifier *>(SS->getScopeRep());
+              TemplateResult 
+                = TemplateTy::make(Context.getQualifiedTemplateName(Qualifier, 
+                                                                    false,
+                                                                  OvlTemplate));              
+            } else {
+              TemplateResult = TemplateTy::make(TemplateName(OvlTemplate));
+            }
             return TNK_Function_template;
           }
           
diff --git a/lib/Sema/SemaTemplateInstantiateExpr.cpp b/lib/Sema/SemaTemplateInstantiateExpr.cpp
index dcf2ebcd2e..31c184fbc2 100644
--- a/lib/Sema/SemaTemplateInstantiateExpr.cpp
+++ b/lib/Sema/SemaTemplateInstantiateExpr.cpp
@@ -109,7 +109,8 @@ TemplateExprInstantiator::VisitUnresolvedFunctionNameExpr(
 Sema::OwningExprResult
 TemplateExprInstantiator::VisitTemplateIdRefExpr(TemplateIdRefExpr *E) {
   TemplateName Template 
-    = SemaRef.InstantiateTemplateName(E->getTemplateName(), E->getTemplateNameLoc(),
+    = SemaRef.InstantiateTemplateName(E->getTemplateName(), 
+                                      E->getTemplateNameLoc(),
                                       TemplateArgs);
   // FIXME: Can InstantiateTemplateName report an error?