Push overloaded function templates through the parser using a totally different
leaked data structure than before.  This kills off the last remaining 
explicit uses of OverloadedFunctionDecl in Sema.                                         


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90306 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 6c9ecf0..a63db14 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -2354,8 +2354,9 @@
     }
   }
 
-  assert(Name.getAsOverloadedFunctionDecl());
-  return Name.getAsOverloadedFunctionDecl()->getDeclName();
+  OverloadedTemplateStorage *Storage = Name.getAsOverloadedTemplate();
+  assert(Storage);
+  return (*Storage->begin())->getDeclName();
 }
 
 TemplateName ASTContext::getCanonicalTemplateName(TemplateName Name) {
@@ -2364,27 +2365,7 @@
   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()) {
-    OverloadedFunctionDecl *CanonOvl = 0;
-    for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(),
-                                                FEnd = Ovl->function_end();
-         F != FEnd; ++F) {
-      Decl *Canon = F->get()->getCanonicalDecl();
-      if (CanonOvl || Canon != F->get()) {
-        if (!CanonOvl)
-          CanonOvl = OverloadedFunctionDecl::Create(*this,
-                                                    Ovl->getDeclContext(),
-                                                    Ovl->getDeclName());
-
-        CanonOvl->addOverload(
-                    AnyFunctionDecl::getFromNamedDecl(cast<NamedDecl>(Canon)));
-      }
-    }
-
-    return TemplateName(CanonOvl? CanonOvl : Ovl);
-  }
+  assert(!Name.getAsOverloadedTemplate());
 
   DependentTemplateName *DTN = Name.getAsDependentTemplateName();
   assert(DTN && "Non-dependent template names must refer to template decls.");
@@ -3690,6 +3671,29 @@
   ObjCConstantStringType = getObjCInterfaceType(Decl);
 }
 
+/// \brief Retrieve the template name that corresponds to a non-empty
+/// lookup.
+TemplateName ASTContext::getOverloadedTemplateName(NamedDecl * const *Begin,
+                                                   NamedDecl * const *End) {
+  unsigned size = End - Begin;
+  assert(size > 1 && "set is not overloaded!");
+
+  void *memory = Allocate(sizeof(OverloadedTemplateStorage) +
+                          size * sizeof(FunctionTemplateDecl*));
+  OverloadedTemplateStorage *OT = new(memory) OverloadedTemplateStorage(size);
+
+  NamedDecl **Storage = OT->getStorage();
+  for (NamedDecl * const *I = Begin; I != End; ++I) {
+    NamedDecl *D = *I;
+    assert(isa<FunctionTemplateDecl>(D) ||
+           (isa<UsingShadowDecl>(D) &&
+            isa<FunctionTemplateDecl>(D->getUnderlyingDecl())));
+    *Storage++ = D;
+  }
+
+  return TemplateName(OT);
+}
+
 /// \brief Retrieve the template name that represents a qualified
 /// template name such as \c std::vector.
 TemplateName ASTContext::getQualifiedTemplateName(NestedNameSpecifier *NNS,
@@ -3709,25 +3713,6 @@
   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 5b4cf0a..b56c0ce 100644
--- a/lib/AST/TemplateName.cpp
+++ b/lib/AST/TemplateName.cpp
@@ -29,25 +29,14 @@
   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()) {
     return isa<TemplateTemplateParmDecl>(Template) ||
       Template->getDeclContext()->isDependentContext();
   }
 
-  if (OverloadedFunctionDecl *Ovl = getAsOverloadedFunctionDecl())
-    return Ovl->getDeclContext()->isDependentContext();
+  assert(!getAsOverloadedTemplate() &&
+         "overloaded templates shouldn't survive to here");
 
   return true;
 }
@@ -57,9 +46,6 @@
                     bool SuppressNNS) const {
   if (TemplateDecl *Template = Storage.dyn_cast<TemplateDecl *>())
     OS << Template->getNameAsString();
-  else if (OverloadedFunctionDecl *Ovl
-             = Storage.dyn_cast<OverloadedFunctionDecl *>())
-    OS << Ovl->getNameAsString();
   else if (QualifiedTemplateName *QTN = getAsQualifiedTemplateName()) {
     if (!SuppressNNS)
       QTN->getQualifier()->print(OS, Policy);
@@ -84,13 +70,3 @@
   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/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index b44d977..c87899b 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1765,13 +1765,8 @@
       
     case UnqualifiedId::IK_TemplateId: {
       TemplateName TName
-        = TemplateName::getFromVoidPointer(Name.TemplateId->Template);    
-      if (TemplateDecl *Template = TName.getAsTemplateDecl())
-        return Template->getDeclName();
-      if (OverloadedFunctionDecl *Ovl = TName.getAsOverloadedFunctionDecl())
-        return Ovl->getDeclName();
-      
-      return DeclarationName();
+        = TemplateName::getFromVoidPointer(Name.TemplateId->Template);
+      return Context.getNameForTemplate(TName);
     }
   }
   
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index ae6ba32..de1816c 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -665,9 +665,9 @@
 
   if (TemplateDecl *TD = TName.getAsTemplateDecl())
     R.addDecl(TD);
-  else if (OverloadedFunctionDecl *OD
-             = TName.getAsOverloadedFunctionDecl())
-    for (OverloadIterator I(OD), E; I != E; ++I)
+  else if (OverloadedTemplateStorage *OT = TName.getAsOverloadedTemplate())
+    for (OverloadedTemplateStorage::iterator I = OT->begin(), E = OT->end();
+           I != E; ++I)
       R.addDecl(*I);
 
   R.resolveKind();
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 565581a..f5e5569 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -108,36 +108,36 @@
   if (R.empty())
     return TNK_Non_template;
 
-  NamedDecl *Template = R.getAsSingleDecl(Context);
+  TemplateName Template;
+  TemplateNameKind TemplateKind;
 
-  if (SS.isSet() && !SS.isInvalid()) {
-    NestedNameSpecifier *Qualifier
-      = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
-    if (OverloadedFunctionDecl *Ovl
-          = dyn_cast<OverloadedFunctionDecl>(Template))
-      TemplateResult
-        = TemplateTy::make(Context.getQualifiedTemplateName(Qualifier, false,
-                                                            Ovl));
-    else
-      TemplateResult
-        = TemplateTy::make(Context.getQualifiedTemplateName(Qualifier, false,
-                                                 cast<TemplateDecl>(Template)));
-  } else if (OverloadedFunctionDecl *Ovl
-               = dyn_cast<OverloadedFunctionDecl>(Template)) {
-    TemplateResult = TemplateTy::make(TemplateName(Ovl));
+  unsigned ResultCount = R.end() - R.begin();
+  if (ResultCount > 1) {
+    // We assume that we'll preserve the qualifier from a function
+    // template name in other ways.
+    Template = Context.getOverloadedTemplateName(R.begin(), R.end());
+    TemplateKind = TNK_Function_template;
   } else {
-    TemplateResult = TemplateTy::make(
-                                  TemplateName(cast<TemplateDecl>(Template)));
+    TemplateDecl *TD = cast<TemplateDecl>((*R.begin())->getUnderlyingDecl());
+
+    if (SS.isSet() && !SS.isInvalid()) {
+      NestedNameSpecifier *Qualifier
+        = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
+      Template = Context.getQualifiedTemplateName(Qualifier, false, TD);
+    } else {
+      Template = TemplateName(TD);
+    }
+
+    if (isa<FunctionTemplateDecl>(TD))
+      TemplateKind = TNK_Function_template;
+    else {
+      assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD));
+      TemplateKind = TNK_Type_template;
+    }
   }
 
-  if (isa<ClassTemplateDecl>(Template) ||
-      isa<TemplateTemplateParmDecl>(Template))
-    return TNK_Type_template;
-
-  assert((isa<FunctionTemplateDecl>(Template) ||
-          isa<OverloadedFunctionDecl>(Template)) &&
-         "Unhandled template kind in Sema::isTemplateName");
-  return TNK_Function_template;  
+  TemplateResult = TemplateTy::make(Template);
+  return TemplateKind;
 }
 
 void Sema::LookupTemplateName(LookupResult &Found,