Switch to using an explicit scope object to ensure we don't forget to pop ObjC

type parameters off the scope, and fix the cases where we failed to do so.

llvm-svn: 251875

1 files changed, 39 insertions, 24 deletions

diff --git a/clang/lib/Parse/ParseObjc.cpp b/clang/lib/Parse/ParseObjc.cpp
index 763bcc185aa..4ac8f42f136 100644
--- a/clang/lib/Parse/ParseObjc.cpp
+++ b/clang/lib/Parse/ParseObjc.cpp
@@ -94,6 +94,28 @@ Parser::DeclGroupPtrTy Parser::ParseObjCAtDirectives() {
   return Actions.ConvertDeclToDeclGroup(SingleDecl);
 }
 
+/// Class to handle popping type parameters when leaving the scope.
+class Parser::ObjCTypeParamListScope {
+  Sema &Actions;
+  Scope *S;
+  ObjCTypeParamList *Params;
+public:
+  ObjCTypeParamListScope(Sema &Actions, Scope *S)
+      : Actions(Actions), S(S), Params(nullptr) {}
+  ~ObjCTypeParamListScope() {
+    leave();
+  }
+  void enter(ObjCTypeParamList *P) {
+    assert(!Params);
+    Params = P;
+  }
+  void leave() {
+    if (Params)
+      Actions.popObjCTypeParamList(S, Params);
+    Params = nullptr;
+  }
+};
+
 ///
 /// objc-class-declaration:
 ///    '@' 'class' objc-class-forward-decl (',' objc-class-forward-decl)* ';'
@@ -121,11 +143,8 @@ Parser::ParseObjCAtClassDeclaration(SourceLocation atLoc) {
 
     // Parse the optional objc-type-parameter-list.
     ObjCTypeParamList *TypeParams = nullptr;
-    if (Tok.is(tok::less)) {
+    if (Tok.is(tok::less))
       TypeParams = parseObjCTypeParamList();
-      if (TypeParams)
-        Actions.popObjCTypeParamList(getCurScope(), TypeParams);
-    }
     ClassTypeParams.push_back(TypeParams);
     if (!TryConsumeToken(tok::comma))
       break;
@@ -221,11 +240,10 @@ Decl *Parser::ParseObjCAtInterfaceDeclaration(SourceLocation AtLoc,
   SourceLocation LAngleLoc, EndProtoLoc;
   SmallVector<IdentifierLocPair, 8> ProtocolIdents;
   ObjCTypeParamList *typeParameterList = nullptr;
-  if (Tok.is(tok::less)) {
-    typeParameterList = parseObjCTypeParamListOrProtocolRefs(LAngleLoc, 
-                                                             ProtocolIdents,
-                                                             EndProtoLoc);
-  }
+  ObjCTypeParamListScope typeParamScope(Actions, getCurScope());
+  if (Tok.is(tok::less))
+    typeParameterList = parseObjCTypeParamListOrProtocolRefs(
+        typeParamScope, LAngleLoc, ProtocolIdents, EndProtoLoc);
 
   if (Tok.is(tok::l_paren) &&
       !isKnownToBeTypeSpecifier(GetLookAheadToken(1))) { // we have a category.
@@ -286,9 +304,6 @@ Decl *Parser::ParseObjCAtInterfaceDeclaration(SourceLocation AtLoc,
       
     ParseObjCInterfaceDeclList(tok::objc_not_keyword, CategoryType);
 
-    if (typeParameterList)
-      Actions.popObjCTypeParamList(getCurScope(), typeParameterList);
-
     return CategoryType;
   }
   // Parse a class interface.
@@ -370,9 +385,6 @@ Decl *Parser::ParseObjCAtInterfaceDeclaration(SourceLocation AtLoc,
 
   ParseObjCInterfaceDeclList(tok::objc_interface, ClsType);
 
-  if (typeParameterList)
-    Actions.popObjCTypeParamList(getCurScope(), typeParameterList);
-
   return ClsType;
 }
 
@@ -432,10 +444,9 @@ static void addContextSensitiveTypeNullability(Parser &P,
 ///
 /// \param rAngleLoc The location of the ending '>'.
 ObjCTypeParamList *Parser::parseObjCTypeParamListOrProtocolRefs(
-                         SourceLocation &lAngleLoc,
-                         SmallVectorImpl<IdentifierLocPair> &protocolIdents,
-                         SourceLocation &rAngleLoc,
-                         bool mayBeProtocolList) {
+    ObjCTypeParamListScope &Scope, SourceLocation &lAngleLoc,
+    SmallVectorImpl<IdentifierLocPair> &protocolIdents,
+    SourceLocation &rAngleLoc, bool mayBeProtocolList) {
   assert(Tok.is(tok::less) && "Not at the beginning of a type parameter list");
 
   // Within the type parameter list, don't treat '>' as an operator.
@@ -580,12 +591,13 @@ ObjCTypeParamList *Parser::parseObjCTypeParamListOrProtocolRefs(
     makeProtocolIdentsIntoTypeParameters();
   }
 
-  // Form the type parameter list.
+  // Form the type parameter list and enter its scope.
   ObjCTypeParamList *list = Actions.actOnObjCTypeParamList(
                               getCurScope(),
                               lAngleLoc,
                               typeParams,
                               rAngleLoc);
+  Scope.enter(list);
 
   // Clear out the angle locations; they're used by the caller to indicate
   // whether there are any protocol references.
@@ -599,8 +611,10 @@ ObjCTypeParamList *Parser::parseObjCTypeParamList() {
   SourceLocation lAngleLoc;
   SmallVector<IdentifierLocPair, 1> protocolIdents;
   SourceLocation rAngleLoc;
-  return parseObjCTypeParamListOrProtocolRefs(lAngleLoc, protocolIdents, 
-                                              rAngleLoc, 
+
+  ObjCTypeParamListScope Scope(Actions, getCurScope());
+  return parseObjCTypeParamListOrProtocolRefs(Scope, lAngleLoc, protocolIdents,
+                                              rAngleLoc,
                                               /*mayBeProtocolList=*/false);
 }
 
@@ -2110,8 +2124,9 @@ Parser::ParseObjCAtImplementationDeclaration(SourceLocation AtLoc) {
     SourceLocation lAngleLoc, rAngleLoc;
     SmallVector<IdentifierLocPair, 8> protocolIdents;
     SourceLocation diagLoc = Tok.getLocation();
-    if (parseObjCTypeParamListOrProtocolRefs(lAngleLoc, protocolIdents, 
-                                             rAngleLoc)) {
+    ObjCTypeParamListScope typeParamScope(Actions, getCurScope());
+    if (parseObjCTypeParamListOrProtocolRefs(typeParamScope, lAngleLoc,
+                                             protocolIdents, rAngleLoc)) {
       Diag(diagLoc, diag::err_objc_parameterized_implementation)
         << SourceRange(diagLoc, PrevTokLocation);
     } else if (lAngleLoc.isValid()) {