Introduce reference counting for statements and expressions, using it

to allow sharing of nodes. Simplifies some aspects of template
instantiation, and fixes both PR3444 and <rdar://problem/6757457>.

llvm-svn: 78450

3 files changed, 18 insertions, 24 deletions

diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index 6094e6dae03..295607b7399 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -2821,14 +2821,6 @@ public:
 
   NamedDecl *InstantiateCurrentDeclRef(NamedDecl *D);
     
-  // Simple function for cloning expressions.
-  template<typename T> 
-  OwningExprResult Clone(T *E) {
-    assert(!E->isValueDependent() && !E->isTypeDependent() &&
-           "expression is value or type dependent!");
-    return Owned(E->Clone(Context));
-  }
-  
   // Objective-C declarations.
   virtual DeclPtrTy ActOnStartClassInterface(SourceLocation AtInterfaceLoc,
                                              IdentifierInfo *ClassName,
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 021a6ad2ab4..1c98fca6af4 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -222,7 +222,8 @@ Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
   if (InstantiatedAssertExpr.isInvalid())
     return 0;
 
-  OwningExprResult Message = SemaRef.Clone(D->getMessage());
+  OwningExprResult Message(SemaRef, D->getMessage());
+  D->getMessage()->Retain();
   Decl *StaticAssert 
     = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(), 
                                            move(InstantiatedAssertExpr),
diff --git a/clang/lib/Sema/SemaTemplateInstantiateExpr.cpp b/clang/lib/Sema/SemaTemplateInstantiateExpr.cpp
index 2e7ed1a6326..1e97f5fcc46 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateExpr.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateExpr.cpp
@@ -57,53 +57,53 @@ Sema::OwningExprResult TemplateExprInstantiator::VisitExpr(Expr *E) {
 
 Sema::OwningExprResult
 TemplateExprInstantiator::VisitPredefinedExpr(PredefinedExpr *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult
 TemplateExprInstantiator::VisitIntegerLiteral(IntegerLiteral *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult
 TemplateExprInstantiator::VisitFloatingLiteral(FloatingLiteral *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult
 TemplateExprInstantiator::VisitStringLiteral(StringLiteral *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult
 TemplateExprInstantiator::VisitCharacterLiteral(CharacterLiteral *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult 
 TemplateExprInstantiator::VisitImaginaryLiteral(ImaginaryLiteral *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult
 TemplateExprInstantiator::VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult
 TemplateExprInstantiator::VisitCXXNullPtrLiteralExpr(CXXNullPtrLiteralExpr *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult
 TemplateExprInstantiator::VisitGNUNullExpr(GNUNullExpr *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult 
 TemplateExprInstantiator::VisitUnresolvedFunctionNameExpr(
                                               UnresolvedFunctionNameExpr *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult
@@ -706,7 +706,8 @@ TemplateExprInstantiator::VisitImplicitValueInitExpr(
                                                   ImplicitValueInitExpr *E) {
   assert(!E->isTypeDependent() && !E->isValueDependent() &&
          "ImplicitValueInitExprs are never dependent");
-  return SemaRef.Clone(E);
+  E->Retain();
+  return SemaRef.Owned(E);
 }
 
 Sema::OwningExprResult 
@@ -1110,7 +1111,7 @@ TemplateExprInstantiator::VisitCXXFunctionalCastExpr(
 
 Sema::OwningExprResult 
 TemplateExprInstantiator::VisitCXXZeroInitValueExpr(CXXZeroInitValueExpr *E) {
-  return SemaRef.Clone(E);
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult 
@@ -1289,7 +1290,7 @@ TemplateExprInstantiator::VisitCXXUnresolvedMemberExpr(
 //----------------------------------------------------------------------------
 Sema::OwningExprResult 
 TemplateExprInstantiator::VisitObjCStringLiteral(ObjCStringLiteral *E) {
-  return SemaRef.Owned(E->Clone(SemaRef.Context));
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult 
@@ -1314,12 +1315,12 @@ TemplateExprInstantiator::VisitObjCMessageExpr(ObjCMessageExpr *E) {
 
 Sema::OwningExprResult 
 TemplateExprInstantiator::VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 
-  return SemaRef.Owned(E->Clone(SemaRef.Context));
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult 
 TemplateExprInstantiator::VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 
-  return SemaRef.Owned(E->Clone(SemaRef.Context));
+  return SemaRef.Owned(E->Retain());
 }
 
 Sema::OwningExprResult