ExpectAndConsume: Diagnose errors automatically

 1) Teach ExpectAndConsume() to emit expected and expected-after diagnostics
    using the generic diagnostic descriptions added in r197972, eliminating another
    set of trivial err_expected_* variations while maintaining existing behaviour.

 2) Lift SkipUntil() recovery out of ExpectAndConsume(). The Expect/Consume
    family of functions are primitive parser operations that now have the
    well-defined property of operating on single tokens. Factoring out recovery
    exposes opportunities for more consistent and tailored error recover at the
    call sites instead of just relying on a bottled SkipUntil formula.

llvm-svn: 198270

10 files changed, 157 insertions, 166 deletions

diff --git a/clang/lib/Parse/ParseCXXInlineMethods.cpp b/clang/lib/Parse/ParseCXXInlineMethods.cpp
index 95502143b0f..feff7fb724a 100644
--- a/clang/lib/Parse/ParseCXXInlineMethods.cpp
+++ b/clang/lib/Parse/ParseCXXInlineMethods.cpp
@@ -96,9 +96,9 @@ NamedDecl *Parser::ParseCXXInlineMethodDef(AccessSpecifier AS,
       Diag(KWLoc, diag::err_default_delete_in_multiple_declaration)
         << Delete;
       SkipUntil(tok::semi);
-    } else {
-      ExpectAndConsume(tok::semi, diag::err_expected_semi_after,
-                       Delete ? "delete" : "default", tok::semi);
+    } else if (ExpectAndConsume(tok::semi, diag::err_expected_after,
+                                Delete ? "delete" : "default")) {
+      SkipUntil(tok::semi);
     }
 
     return FnD;
diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index f664cf20409..60cb48f6760 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -171,10 +171,10 @@ void Parser::ParseGNUAttributes(ParsedAttributes &attrs,
                      AttributeList::AS_GNU);
       }
     }
-    if (ExpectAndConsume(tok::r_paren, diag::err_expected_rparen))
+    if (ExpectAndConsume(tok::r_paren))
       SkipUntil(tok::r_paren, StopAtSemi);
     SourceLocation Loc = Tok.getLocation();
-    if (ExpectAndConsume(tok::r_paren, diag::err_expected_rparen))
+    if (ExpectAndConsume(tok::r_paren))
       SkipUntil(tok::r_paren, StopAtSemi);
     if (endLoc)
       *endLoc = Loc;
@@ -322,7 +322,7 @@ void Parser::ParseGNUAttributeArgs(IdentifierInfo *AttrName,
   }
 
   SourceLocation RParen = Tok.getLocation();
-  if (!ExpectAndConsume(tok::r_paren, diag::err_expected_rparen)) {
+  if (!ExpectAndConsume(tok::r_paren)) {
     SourceLocation AttrLoc = ScopeLoc.isValid() ? ScopeLoc : AttrNameLoc;
     Attrs.addNew(AttrName, SourceRange(AttrLoc, RParen), ScopeName, ScopeLoc,
                  ArgExprs.data(), ArgExprs.size(), Syntax);
@@ -826,8 +826,10 @@ void Parser::ParseAvailabilityAttribute(IdentifierInfo &Availability,
   IdentifierLoc *Platform = ParseIdentifierLoc();
 
   // Parse the ',' following the platform name.
-  if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "", tok::r_paren))
+  if (ExpectAndConsume(tok::comma)) {
+    SkipUntil(tok::r_paren, StopAtSemi);
     return;
+  }
 
   // If we haven't grabbed the pointers for the identifiers
   // "introduced", "deprecated", and "obsoleted", do so now.
@@ -857,11 +859,9 @@ void Parser::ParseAvailabilityAttribute(IdentifierInfo &Availability,
       }
       UnavailableLoc = KeywordLoc;
 
-      if (Tok.isNot(tok::comma))
-        break;
-
-      ConsumeToken();
-      continue;
+      if (TryConsumeToken(tok::comma))
+        continue;
+      break;
     }
 
     if (Tok.isNot(tok::equal)) {
@@ -2385,7 +2385,7 @@ void Parser::ParseAlignmentSpecifier(ParsedAttributes &Attrs,
   SourceLocation KWLoc = ConsumeToken();
 
   BalancedDelimiterTracker T(*this, tok::l_paren);
-  if (T.expectAndConsume(diag::err_expected_lparen))
+  if (T.expectAndConsume())
     return;
 
   SourceLocation EllipsisLoc;
@@ -2496,8 +2496,8 @@ Parser::DiagnoseMissingSemiAfterTagDefinition(DeclSpec &DS, AccessSpecifier AS,
     return false;
 
   Diag(PP.getLocForEndOfToken(DS.getRepAsDecl()->getLocEnd()),
-       diag::err_expected_semi_after_tagdecl)
-    << DeclSpec::getSpecifierName(DS.getTypeSpecType());
+       diag::err_expected_after)
+      << DeclSpec::getSpecifierName(DS.getTypeSpecType()) << tok::semi;
 
   // Try to recover from the typo, by dropping the tag definition and parsing
   // the problematic tokens as a type.
@@ -3468,7 +3468,7 @@ void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
         continue;
       }
       ConsumeToken();
-      ExpectAndConsume(tok::l_paren, diag::err_expected_lparen);
+      ExpectAndConsume(tok::l_paren);
       if (!Tok.is(tok::identifier)) {
         Diag(Tok, diag::err_expected) << tok::identifier;
         SkipUntil(tok::semi);
@@ -3479,7 +3479,7 @@ void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
                         Tok.getIdentifierInfo(), Fields);
       FieldDecls.insert(FieldDecls.end(), Fields.begin(), Fields.end());
       ConsumeToken();
-      ExpectAndConsume(tok::r_paren, diag::err_expected_rparen);
+      ExpectAndConsume(tok::r_paren);
     }
 
     if (TryConsumeToken(tok::semi))
@@ -3757,8 +3757,7 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
     TUK = DS.isFriendSpecified() ? Sema::TUK_Friend : Sema::TUK_Declaration;
     if (Tok.isNot(tok::semi)) {
       // A semicolon was missing after this declaration. Diagnose and recover.
-      ExpectAndConsume(tok::semi, diag::err_expected_semi_after_tagdecl,
-                       "enum");
+      ExpectAndConsume(tok::semi, diag::err_expected_after, "enum");
       PP.EnterToken(Tok);
       Tok.setKind(tok::semi);
     }
@@ -3987,7 +3986,7 @@ void Parser::ParseEnumBody(SourceLocation StartLoc, Decl *EnumDecl) {
   // was probably forgotten.
   bool CanBeBitfield = getCurScope()->getFlags() & Scope::ClassScope;
   if (!isValidAfterTypeSpecifier(CanBeBitfield)) {
-    ExpectAndConsume(tok::semi, diag::err_expected_semi_after_tagdecl, "enum");
+    ExpectAndConsume(tok::semi, diag::err_expected_after, "enum");
     // Push this token back into the preprocessor and change our current token
     // to ';' so that the rest of the code recovers as though there were an
     // ';' after the definition.
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 6098c0c8970..d3283eb21bd 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -263,8 +263,8 @@ Decl *Parser::ParseNamespaceAlias(SourceLocation NamespaceLoc,
 
   // Eat the ';'.
   DeclEnd = Tok.getLocation();
-  ExpectAndConsume(tok::semi, diag::err_expected_semi_after_namespace_name,
-                   "", tok::semi);
+  if (ExpectAndConsume(tok::semi, diag::err_expected_semi_after_namespace_name))
+    SkipUntil(tok::semi);
 
   return Actions.ActOnNamespaceAliasDef(getCurScope(), NamespaceLoc, AliasLoc, Alias,
                                         SS, IdentLoc, Ident);
@@ -428,10 +428,10 @@ Decl *Parser::ParseUsingDirective(unsigned Context,
 
   // Eat ';'.
   DeclEnd = Tok.getLocation();
-  ExpectAndConsume(tok::semi,
-                   GNUAttr ? diag::err_expected_semi_after_attribute_list
-                           : diag::err_expected_semi_after_namespace_name, 
-                   "", tok::semi);
+  if (ExpectAndConsume(tok::semi,
+                       GNUAttr ? diag::err_expected_semi_after_attribute_list
+                               : diag::err_expected_semi_after_namespace_name))
+    SkipUntil(tok::semi);
 
   return Actions.ActOnUsingDirective(getCurScope(), UsingLoc, NamespcLoc, SS,
                                      IdentLoc, NamespcName, attrs.getList());
@@ -588,10 +588,11 @@ Decl *Parser::ParseUsingDeclaration(unsigned Context,
 
   // Eat ';'.
   DeclEnd = Tok.getLocation();
-  ExpectAndConsume(tok::semi, diag::err_expected_semi_after,
-                   !Attrs.empty() ? "attributes list" :
-                   IsAliasDecl ? "alias declaration" : "using declaration",
-                   tok::semi);
+  if (ExpectAndConsume(tok::semi, diag::err_expected_after,
+                       !Attrs.empty() ? "attributes list"
+                                      : IsAliasDecl ? "alias declaration"
+                                                    : "using declaration"))
+    SkipUntil(tok::semi);
 
   // Diagnose an attempt to declare a templated using-declaration.
   // In C++11, alias-declarations can be templates:
@@ -664,8 +665,10 @@ Decl *Parser::ParseStaticAssertDeclaration(SourceLocation &DeclEnd){
     return 0;
   }
 
-  if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "", tok::semi))
+  if (ExpectAndConsume(tok::comma)) {
+    SkipUntil(tok::semi);
     return 0;
+  }
 
   if (!isTokenStringLiteral()) {
     Diag(Tok, diag::err_expected_string_literal)
@@ -1373,8 +1376,8 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
     TUK = DS.isFriendSpecified() ? Sema::TUK_Friend : Sema::TUK_Declaration;
     if (Tok.isNot(tok::semi)) {
       // A semicolon was missing after this declaration. Diagnose and recover.
-      ExpectAndConsume(tok::semi, diag::err_expected_semi_after_tagdecl,
-        DeclSpec::getSpecifierName(TagType));
+      ExpectAndConsume(tok::semi, diag::err_expected_after,
+                       DeclSpec::getSpecifierName(TagType));
       PP.EnterToken(Tok);
       Tok.setKind(tok::semi);
     }
@@ -1637,8 +1640,8 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
   if (TUK == Sema::TUK_Definition &&
       (TemplateInfo.Kind || !isValidAfterTypeSpecifier(false))) {
     if (Tok.isNot(tok::semi)) {
-      ExpectAndConsume(tok::semi, diag::err_expected_semi_after_tagdecl,
-        DeclSpec::getSpecifierName(TagType));
+      ExpectAndConsume(tok::semi, diag::err_expected_after,
+                       DeclSpec::getSpecifierName(TagType));
       // Push this token back into the preprocessor and change our current token
       // to ';' so that the rest of the code recovers as though there were an
       // ';' after the definition.
@@ -1985,11 +1988,11 @@ void Parser::ParseCXXClassMemberDeclaration(AccessSpecifier AS,
       }
 
       // TODO: recover from mistakenly-qualified operator declarations.
-      if (ExpectAndConsume(tok::semi,
-                           diag::err_expected_semi_after,
-                           "access declaration",
-                           tok::semi))
+      if (ExpectAndConsume(tok::semi, diag::err_expected_after,
+                           "access declaration")) {
+        SkipUntil(tok::semi);
         return;
+      }
 
       Actions.ActOnUsingDeclaration(getCurScope(), AS,
                                     /* HasUsingKeyword */ false,
@@ -3306,11 +3309,11 @@ void Parser::ParseCXX11AttributeSpecifier(ParsedAttributes &attrs,
     }
   }
 
-  if (ExpectAndConsume(tok::r_square, diag::err_expected_rsquare))
+  if (ExpectAndConsume(tok::r_square))
     SkipUntil(tok::r_square);
   if (endLoc)
     *endLoc = Tok.getLocation();
-  if (ExpectAndConsume(tok::r_square, diag::err_expected_rsquare))
+  if (ExpectAndConsume(tok::r_square))
     SkipUntil(tok::r_square);
 }
 
@@ -3381,7 +3384,7 @@ void Parser::ParseMicrosoftAttributes(ParsedAttributes &attrs,
     ConsumeBracket();
     SkipUntil(tok::r_square, StopAtSemi | StopBeforeMatch);
     if (endLoc) *endLoc = Tok.getLocation();
-    ExpectAndConsume(tok::r_square, diag::err_expected_rsquare);
+    ExpectAndConsume(tok::r_square);
   }
 }
 
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index 96f8f55a738..e7bc682211c 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -1296,7 +1296,7 @@ Parser::ParsePostfixExpressionSuffix(ExprResult LHS) {
         }
 
         if (!LHS.isInvalid()) {
-          if (ExpectAndConsume(tok::l_paren, diag::err_expected_lparen, ""))
+          if (ExpectAndConsume(tok::l_paren))
             LHS = ExprError();
           else
             Loc = PrevTokLocation;
@@ -1698,8 +1698,10 @@ ExprResult Parser::ParseBuiltinPrimaryExpression() {
   case tok::kw___builtin_va_arg: {
     ExprResult Expr(ParseAssignmentExpression());
 
-    if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren))
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
       Expr = ExprError();
+    }
 
     TypeResult Ty = ParseTypeName();
 
@@ -1722,8 +1724,10 @@ ExprResult Parser::ParseBuiltinPrimaryExpression() {
       return ExprError();
     }
 
-    if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren))
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
       return ExprError();
+    }
 
     // We must have at least one identifier here.
     if (Tok.isNot(tok::identifier)) {
@@ -1798,16 +1802,20 @@ ExprResult Parser::ParseBuiltinPrimaryExpression() {
       SkipUntil(tok::r_paren, StopAtSemi);
       return Cond;
     }
-    if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren))
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
       return ExprError();
+    }
 
     ExprResult Expr1(ParseAssignmentExpression());
     if (Expr1.isInvalid()) {
       SkipUntil(tok::r_paren, StopAtSemi);
       return Expr1;
     }
-    if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren))
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
       return ExprError();
+    }
 
     ExprResult Expr2(ParseAssignmentExpression());
     if (Expr2.isInvalid()) {
@@ -1829,11 +1837,12 @@ ExprResult Parser::ParseBuiltinPrimaryExpression() {
       SkipUntil(tok::r_paren, StopAtSemi);
       return ExprError();
     }
-    
-    if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "", 
-                         tok::r_paren))
+
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
       return ExprError();
-    
+    }
+
     // Second argument is the type to bitcast to.
     TypeResult DestTy = ParseTypeName();
     if (DestTy.isInvalid())
@@ -1857,11 +1866,12 @@ ExprResult Parser::ParseBuiltinPrimaryExpression() {
       SkipUntil(tok::r_paren, StopAtSemi);
       return ExprError();
     }
-    
-    if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "", 
-                         tok::r_paren))
+
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
       return ExprError();
-    
+    }
+
     // Second argument is the type to bitcast to.
     TypeResult DestTy = ParseTypeName();
     if (DestTy.isInvalid())
@@ -1938,7 +1948,7 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
                       Tok.is(tok::kw___bridge_retained) ||
                       Tok.is(tok::kw___bridge_retain)));
   if (BridgeCast && !getLangOpts().ObjCAutoRefCount) {
-    if (Tok.isNot(tok::kw___bridge)) {
+    if (!TryConsumeToken(tok::kw___bridge)) {
       StringRef BridgeCastName = Tok.getName();
       SourceLocation BridgeKeywordLoc = ConsumeToken();
       if (!PP.getSourceManager().isInSystemHeader(BridgeKeywordLoc))
@@ -1946,8 +1956,6 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
           << BridgeCastName
           << FixItHint::CreateReplacement(BridgeKeywordLoc, "");
     }
-    else
-      ConsumeToken(); // consume __bridge
     BridgeCast = false;
   }
   
@@ -2195,7 +2203,7 @@ ExprResult Parser::ParseGenericSelectionExpression() {
     Diag(KeyLoc, diag::ext_c11_generic_selection);
 
   BalancedDelimiterTracker T(*this, tok::l_paren);
-  if (T.expectAndConsume(diag::err_expected_lparen))
+  if (T.expectAndConsume())
     return ExprError();
 
   ExprResult ControllingExpr;
@@ -2210,7 +2218,7 @@ ExprResult Parser::ParseGenericSelectionExpression() {
     }
   }
 
-  if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "")) {
+  if (ExpectAndConsume(tok::comma)) {
     SkipUntil(tok::r_paren, StopAtSemi);
     return ExprError();
   }
@@ -2242,7 +2250,7 @@ ExprResult Parser::ParseGenericSelectionExpression() {
     }
     Types.push_back(Ty);
 
-    if (ExpectAndConsume(tok::colon, diag::err_expected_colon, "")) {
+    if (ExpectAndConsume(tok::colon)) {
       SkipUntil(tok::r_paren, StopAtSemi);
       return ExprError();
     }
diff --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp
index 61dfbc6d58c..cef5b270e7b 100644
--- a/clang/lib/Parse/ParseExprCXX.cpp
+++ b/clang/lib/Parse/ParseExprCXX.cpp
@@ -1186,7 +1186,7 @@ ExprResult Parser::ParseCXXCasts() {
 
   SourceLocation RAngleBracketLoc = Tok.getLocation();
 
-  if (ExpectAndConsume(tok::greater, diag::err_expected_greater))
+  if (ExpectAndConsume(tok::greater))
     return ExprError(Diag(LAngleBracketLoc, diag::note_matching) << tok::less);
 
   SourceLocation LParenLoc, RParenLoc;
@@ -2747,7 +2747,7 @@ ExprResult Parser::ParseTypeTrait() {
   SourceLocation Loc = ConsumeToken();
   
   BalancedDelimiterTracker Parens(*this, tok::l_paren);
-  if (Parens.expectAndConsume(diag::err_expected_lparen))
+  if (Parens.expectAndConsume())
     return ExprError();
 
   SmallVector<ParsedType, 2> Args;
@@ -2808,7 +2808,7 @@ ExprResult Parser::ParseArrayTypeTrait() {
   SourceLocation Loc = ConsumeToken();
 
   BalancedDelimiterTracker T(*this, tok::l_paren);
-  if (T.expectAndConsume(diag::err_expected_lparen))
+  if (T.expectAndConsume())
     return ExprError();
 
   TypeResult Ty = ParseTypeName();
@@ -2825,7 +2825,7 @@ ExprResult Parser::ParseArrayTypeTrait() {
                                        T.getCloseLocation());
   }
   case ATT_ArrayExtent: {
-    if (ExpectAndConsume(tok::comma, diag::err_expected_comma)) {
+    if (ExpectAndConsume(tok::comma)) {
       SkipUntil(tok::r_paren, StopAtSemi);
       return ExprError();
     }
@@ -2851,7 +2851,7 @@ ExprResult Parser::ParseExpressionTrait() {
   SourceLocation Loc = ConsumeToken();
 
   BalancedDelimiterTracker T(*this, tok::l_paren);
-  if (T.expectAndConsume(diag::err_expected_lparen))
+  if (T.expectAndConsume())
     return ExprError();
 
   ExprResult Expr = ParseExpression();
diff --git a/clang/lib/Parse/ParseObjc.cpp b/clang/lib/Parse/ParseObjc.cpp
index a36d2ea1b41..c8460c0e808 100644
--- a/clang/lib/Parse/ParseObjc.cpp
+++ b/clang/lib/Parse/ParseObjc.cpp
@@ -115,14 +115,12 @@ Parser::ParseObjCAtClassDeclaration(SourceLocation atLoc) {
     ClassLocs.push_back(Tok.getLocation());
     ConsumeToken();
 
-    if (Tok.isNot(tok::comma))
+    if (!TryConsumeToken(tok::comma))
       break;
-
-    ConsumeToken();
   }
 
   // Consume the ';'.
-  if (ExpectAndConsume(tok::semi, diag::err_expected_semi_after, "@class"))
+  if (ExpectAndConsume(tok::semi, diag::err_expected_after, "@class"))
     return Actions.ConvertDeclToDeclGroup(0);
 
   return Actions.ActOnForwardClassDeclaration(atLoc, ClassNames.data(),
@@ -613,8 +611,10 @@ void Parser::ParseObjCPropertyAttribute(ObjCDeclSpec &DS) {
       unsigned DiagID = IsSetter ? diag::err_objc_expected_equal_for_setter :
         diag::err_objc_expected_equal_for_getter;
 
-      if (ExpectAndConsume(tok::equal, DiagID, "", tok::r_paren))
+      if (ExpectAndConsume(tok::equal, DiagID)) {
+        SkipUntil(tok::r_paren, StopAtSemi);
         return;
+      }
 
       if (Tok.is(tok::code_completion)) {
         if (IsSetter)
@@ -639,10 +639,11 @@ void Parser::ParseObjCPropertyAttribute(ObjCDeclSpec &DS) {
         DS.setPropertyAttributes(ObjCDeclSpec::DQ_PR_setter);
         DS.setSetterName(SelIdent);
 
-        if (ExpectAndConsume(tok::colon, 
-                             diag::err_expected_colon_after_setter_name, "",
-                             tok::r_paren))
+        if (ExpectAndConsume(tok::colon,
+                             diag::err_expected_colon_after_setter_name)) {
+          SkipUntil(tok::r_paren, StopAtSemi);
           return;
+        }
       } else {
         DS.setPropertyAttributes(ObjCDeclSpec::DQ_PR_getter);
         DS.setGetterName(SelIdent);
@@ -1057,11 +1058,8 @@ Decl *Parser::ParseObjCMethodDecl(SourceLocation mLoc,
     Sema::ObjCArgInfo ArgInfo;
 
     // Each iteration parses a single keyword argument.
-    if (Tok.isNot(tok::colon)) {
-      Diag(Tok, diag::err_expected) << tok::colon;
+    if (ExpectAndConsume(tok::colon))
       break;
-    }
-    ConsumeToken(); // Eat the ':'.
 
     ArgInfo.Type = ParsedType();
     if (Tok.is(tok::l_paren)) // Parse the argument type if present.
@@ -1211,9 +1209,8 @@ ParseObjCProtocolReferences(SmallVectorImpl<Decl *> &Protocols,
     ProtocolLocs.push_back(Tok.getLocation());
     ConsumeToken();
 
-    if (Tok.isNot(tok::comma))
+    if (!TryConsumeToken(tok::comma))
       break;
-    ConsumeToken();
   }
 
   // Consume the '>'.
@@ -1303,9 +1300,7 @@ void Parser::ParseObjCClassInstanceVariables(Decl *interfaceDecl,
     }
 
     // Set the default visibility to private.
-    if (Tok.is(tok::at)) { // parse objc-visibility-spec
-      ConsumeToken(); // eat the @ sign
-      
+    if (TryConsumeToken(tok::at)) { // parse objc-visibility-spec
       if (Tok.is(tok::code_completion)) {
         Actions.CodeCompleteObjCAtVisibility(getCurScope());
         return cutOffParsing();
@@ -1423,9 +1418,8 @@ Parser::ParseObjCAtProtocolDeclaration(SourceLocation AtLoc,
   IdentifierInfo *protocolName = Tok.getIdentifierInfo();
   SourceLocation nameLoc = ConsumeToken();
 
-  if (Tok.is(tok::semi)) { // forward declaration of one protocol.
+  if (TryConsumeToken(tok::semi)) { // forward declaration of one protocol.
     IdentifierLocPair ProtoInfo(protocolName, nameLoc);
-    ConsumeToken();
     return Actions.ActOnForwardProtocolDeclaration(AtLoc, &ProtoInfo, 1,
                                                    attrs.getList());
   }
@@ -1452,7 +1446,7 @@ Parser::ParseObjCAtProtocolDeclaration(SourceLocation AtLoc,
         break;
     }
     // Consume the ';'.
-    if (ExpectAndConsume(tok::semi, diag::err_expected_semi_after, "@protocol"))
+    if (ExpectAndConsume(tok::semi, diag::err_expected_after, "@protocol"))
       return DeclGroupPtrTy();
 
     return Actions.ActOnForwardProtocolDeclaration(AtLoc,
@@ -1558,9 +1552,8 @@ Parser::ParseObjCAtImplementationDeclaration(SourceLocation AtLoc) {
     // We have a class implementation
     SourceLocation superClassLoc;
     IdentifierInfo *superClassId = 0;
-    if (Tok.is(tok::colon)) {
+    if (TryConsumeToken(tok::colon)) {
       // We have a super class
-      ConsumeToken();
       if (Tok.isNot(tok::identifier)) {
         Diag(Tok, diag::err_expected)
             << tok::identifier; // missing super class name.
@@ -1673,8 +1666,7 @@ Decl *Parser::ParseObjCAtAliasDeclaration(SourceLocation atLoc) {
   }
   IdentifierInfo *classId = Tok.getIdentifierInfo();
   SourceLocation classLoc = ConsumeToken(); // consume class-name;
-  ExpectAndConsume(tok::semi, diag::err_expected_semi_after, 
-                   "@compatibility_alias");
+  ExpectAndConsume(tok::semi, diag::err_expected_after, "@compatibility_alias");
   return Actions.ActOnCompatibilityAlias(atLoc, aliasId, aliasLoc,
                                          classId, classLoc);
 }
@@ -1712,10 +1704,8 @@ Decl *Parser::ParseObjCPropertySynthesize(SourceLocation atLoc) {
     IdentifierInfo *propertyId = Tok.getIdentifierInfo();
     SourceLocation propertyLoc = ConsumeToken(); // consume property name
     SourceLocation propertyIvarLoc;
-    if (Tok.is(tok::equal)) {
+    if (TryConsumeToken(tok::equal)) {
       // property '=' ivar-name
-      ConsumeToken(); // consume '='
-      
       if (Tok.is(tok::code_completion)) {
         Actions.CodeCompleteObjCPropertySynthesizeIvar(getCurScope(), propertyId);
         cutOffParsing();
@@ -1735,7 +1725,7 @@ Decl *Parser::ParseObjCPropertySynthesize(SourceLocation atLoc) {
       break;
     ConsumeToken(); // consume ','
   }
-  ExpectAndConsume(tok::semi, diag::err_expected_semi_after, "@synthesize");
+  ExpectAndConsume(tok::semi, diag::err_expected_after, "@synthesize");
   return 0;
 }
 
@@ -1772,7 +1762,7 @@ Decl *Parser::ParseObjCPropertyDynamic(SourceLocation atLoc) {
       break;
     ConsumeToken(); // consume ','
   }
-  ExpectAndConsume(tok::semi, diag::err_expected_semi_after, "@dynamic");
+  ExpectAndConsume(tok::semi, diag::err_expected_after, "@dynamic");
   return 0;
 }
 
@@ -1790,7 +1780,7 @@ StmtResult Parser::ParseObjCThrowStmt(SourceLocation atLoc) {
     }
   }
   // consume ';'
-  ExpectAndConsume(tok::semi, diag::err_expected_semi_after, "@throw");
+  ExpectAndConsume(tok::semi, diag::err_expected_after, "@throw");
   return Actions.ActOnObjCAtThrowStmt(atLoc, Res.take(), getCurScope());
 }
 
@@ -2485,8 +2475,7 @@ Parser::ParseObjCMessageExpressionBody(SourceLocation LBracLoc,
       KeyIdents.push_back(selIdent);
       KeyLocs.push_back(Loc);
 
-      if (Tok.isNot(tok::colon)) {
-        Diag(Tok, diag::err_expected) << tok::colon;
+      if (ExpectAndConsume(tok::colon)) {
         // We must manually skip to a ']', otherwise the expression skipper will
         // stop at the ']' when it skips to the ';'.  We want it to skip beyond
         // the enclosing expression.
@@ -2494,7 +2483,6 @@ Parser::ParseObjCMessageExpressionBody(SourceLocation LBracLoc,
         return ExprError();
       }
 
-      ConsumeToken(); // Eat the ':'.
       ///  Parse the expression after ':'
       
       if (Tok.is(tok::code_completion)) {
@@ -2761,8 +2749,7 @@ ExprResult Parser::ParseObjCDictionaryLiteral(SourceLocation AtLoc) {
       }
     }
 
-    if (!TryConsumeToken(tok::colon)) {
-      Diag(Tok, diag::err_expected) << tok::colon;
+    if (ExpectAndConsume(tok::colon)) {
       SkipUntil(tok::r_brace, StopAtSemi);
       return ExprError();
     }
@@ -2787,10 +2774,8 @@ ExprResult Parser::ParseObjCDictionaryLiteral(SourceLocation AtLoc) {
       KeyExpr.get(), ValueExpr.get(), EllipsisLoc, None 
     };
     Elements.push_back(Element);
-    
-    if (Tok.is(tok::comma))
-      ConsumeToken(); // Eat the ','.
-    else if (Tok.isNot(tok::r_brace))
+
+    if (!TryConsumeToken(tok::comma) && Tok.isNot(tok::r_brace))
       return ExprError(Diag(Tok, diag::err_expected_either) << tok::r_brace
                                                             << tok::comma);
   }
@@ -2880,14 +2865,13 @@ ExprResult Parser::ParseObjCSelectorExpression(SourceLocation AtLoc) {
   unsigned nColons = 0;
   if (Tok.isNot(tok::r_paren)) {
     while (1) {
-      if (Tok.is(tok::coloncolon)) { // Handle :: in C++.
+      if (TryConsumeToken(tok::coloncolon)) { // Handle :: in C++.
         ++nColons;
         KeyIdents.push_back(0);
-      } else if (Tok.isNot(tok::colon))
-        return ExprError(Diag(Tok, diag::err_expected) << tok::colon);
-
+      } else if (ExpectAndConsume(tok::colon)) // Otherwise expect ':'.
+        return ExprError();
       ++nColons;
-      ConsumeToken(); // Eat the ':' or '::'.
+
       if (Tok.is(tok::r_paren))
         break;
       
diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
index 7f3be42fe6c..88d86056af1 100644
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -449,7 +449,7 @@ StmtResult Parser::ParseSEHExceptBlock(SourceLocation ExceptLoc) {
     raii2(Ident___exception_code, false),
     raii3(Ident_GetExceptionCode, false);
 
-  if(ExpectAndConsume(tok::l_paren,diag::err_expected_lparen))
+  if (ExpectAndConsume(tok::l_paren))
     return StmtError();
 
   ParseScope ExpectScope(this, Scope::DeclScope | Scope::ControlScope);
@@ -470,7 +470,7 @@ StmtResult Parser::ParseSEHExceptBlock(SourceLocation ExceptLoc) {
   if(FilterExpr.isInvalid())
     return StmtError();
 
-  if(ExpectAndConsume(tok::r_paren,diag::err_expected_rparen))
+  if (ExpectAndConsume(tok::r_paren))
     return StmtError();
 
   StmtResult Block(ParseCompoundStatement());
@@ -543,7 +543,7 @@ StmtResult Parser::ParseLabeledStatement(ParsedAttributesWithRange &attrs) {
         SubStmt = Actions.ProcessStmtAttributes(
             SubStmt.get(), TempAttrs.getList(), TempAttrs.Range);
     } else {
-      Diag(Tok, diag::err_expected_semi_after) << "__attribute__";
+      Diag(Tok, diag::err_expected_after) << "__attribute__" << tok::semi;
     }
   }
 
@@ -2627,7 +2627,7 @@ StmtResult Parser::ParseCXXCatchBlock(bool FnCatch) {
   SourceLocation CatchLoc = ConsumeToken();
 
   BalancedDelimiterTracker T(*this, tok::l_paren);
-  if (T.expectAndConsume(diag::err_expected_lparen))
+  if (T.expectAndConsume())
     return StmtError();
 
   // C++ 3.3.2p3:
diff --git a/clang/lib/Parse/ParseTemplate.cpp b/clang/lib/Parse/ParseTemplate.cpp
index 03325db8860..a5471f1294e 100644
--- a/clang/lib/Parse/ParseTemplate.cpp
+++ b/clang/lib/Parse/ParseTemplate.cpp
@@ -316,10 +316,8 @@ bool Parser::ParseTemplateParameters(unsigned Depth,
     Tok.setKind(tok::greater);
     RAngleLoc = Tok.getLocation();
     Tok.setLocation(Tok.getLocation().getLocWithOffset(1));
-  } else if (Tok.is(tok::greater))
-    RAngleLoc = ConsumeToken();
-  else if (Failed) {
-    Diag(Tok.getLocation(), diag::err_expected_greater);
+  } else if (!TryConsumeToken(tok::greater, RAngleLoc) && Failed) {
+    Diag(Tok.getLocation(), diag::err_expected) << tok::greater;
     return true;
   }
   return false;
@@ -675,7 +673,7 @@ bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
 
   switch (Tok.getKind()) {
   default:
-    Diag(Tok.getLocation(), diag::err_expected_greater);
+    Diag(Tok.getLocation(), diag::err_expected) << tok::greater;
     return true;
 
   case tok::greater:
diff --git a/clang/lib/Parse/Parser.cpp b/clang/lib/Parse/Parser.cpp
index d1424899aec..a62d4c3d16a 100644
--- a/clang/lib/Parse/Parser.cpp
+++ b/clang/lib/Parse/Parser.cpp
@@ -152,14 +152,8 @@ static bool IsCommonTypo(tok::TokenKind ExpectedTok, const Token &Tok) {
   }
 }
 
-/// ExpectAndConsume - The parser expects that 'ExpectedTok' is next in the
-/// input.  If so, it is consumed and false is returned.
-///
-/// If the input is malformed, this emits the specified diagnostic.  Next, if
-/// SkipToTok is specified, it calls SkipUntil(SkipToTok).  Finally, true is
-/// returned.
 bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID,
-                              const char *Msg, tok::TokenKind SkipToTok) {
+                              const char *Msg) {
   if (Tok.is(ExpectedTok) || Tok.is(tok::code_completion)) {
     ConsumeAnyToken();
     return false;
@@ -168,29 +162,37 @@ bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID,
   // Detect common single-character typos and resume.
   if (IsCommonTypo(ExpectedTok, Tok)) {
     SourceLocation Loc = Tok.getLocation();
-    Diag(Loc, DiagID)
-      << Msg
-      << FixItHint::CreateReplacement(SourceRange(Loc),
-                                      getTokenSimpleSpelling(ExpectedTok));
+    DiagnosticBuilder DB = Diag(Loc, DiagID);
+    DB << FixItHint::CreateReplacement(SourceRange(Loc),
+                                       getTokenSimpleSpelling(ExpectedTok));
+    if (DiagID == diag::err_expected)
+      DB << ExpectedTok;
+    else if (DiagID == diag::err_expected_after)
+      DB << Msg << ExpectedTok;
+    else
+      DB << Msg;
     ConsumeAnyToken();
 
     // Pretend there wasn't a problem.
     return false;
   }
 
-  const char *Spelling = 0;
   SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation);
-  if (EndLoc.isValid() &&
-      (Spelling = tok::getTokenSimpleSpelling(ExpectedTok))) {
-    // Show what code to insert to fix this problem.
-    Diag(EndLoc, DiagID)
-      << Msg
-      << FixItHint::CreateInsertion(EndLoc, Spelling);
-  } else
-    Diag(Tok, DiagID) << Msg;
+  const char *Spelling = 0;
+  if (EndLoc.isValid())
+    Spelling = tok::getTokenSimpleSpelling(ExpectedTok);
+
+  DiagnosticBuilder DB =
+      Spelling
+          ? Diag(EndLoc, DiagID) << FixItHint::CreateInsertion(EndLoc, Spelling)
+          : Diag(Tok, DiagID);
+  if (DiagID == diag::err_expected)
+    DB << ExpectedTok;
+  else if (DiagID == diag::err_expected_after)
+    DB << Msg << ExpectedTok;
+  else
+    DB << Msg;
 
-  if (SkipToTok != tok::unknown)
-    SkipUntil(SkipToTok, StopAtSemi);
   return true;
 }
 
@@ -725,7 +727,7 @@ Parser::ParseExternalDeclaration(ParsedAttributesWithRange &attrs,
     SourceLocation EndLoc;
     ExprResult Result(ParseSimpleAsm(&EndLoc));
 
-    ExpectAndConsume(tok::semi, diag::err_expected_semi_after,
+    ExpectAndConsume(tok::semi, diag::err_expected_after,
                      "top-level asm block");
 
     if (Result.isInvalid())
@@ -1127,28 +1129,22 @@ Decl *Parser::ParseFunctionDefinition(ParsingDeclarator &D,
   // safe because we're always the sole owner.
   D.getMutableDeclSpec().abort();
 
-  if (Tok.is(tok::equal)) {
+  if (TryConsumeToken(tok::equal)) {
     assert(getLangOpts().CPlusPlus && "Only C++ function definitions have '='");
-    ConsumeToken();
-
     Actions.ActOnFinishFunctionBody(Res, 0, false);
  
     bool Delete = false;
     SourceLocation KWLoc;
-    if (Tok.is(tok::kw_delete)) {
-      Diag(Tok, getLangOpts().CPlusPlus11 ?
-           diag::warn_cxx98_compat_deleted_function :
-           diag::ext_deleted_function);
-
-      KWLoc = ConsumeToken();
+    if (TryConsumeToken(tok::kw_delete, KWLoc)) {
+      Diag(KWLoc, getLangOpts().CPlusPlus11
+                      ? diag::warn_cxx98_compat_deleted_function
+                      : diag::ext_deleted_function);
       Actions.SetDeclDeleted(Res, KWLoc);
       Delete = true;
-    } else if (Tok.is(tok::kw_default)) {
-      Diag(Tok, getLangOpts().CPlusPlus11 ?
-           diag::warn_cxx98_compat_defaulted_function :
-           diag::ext_defaulted_function);
-
-      KWLoc = ConsumeToken();
+    } else if (TryConsumeToken(tok::kw_default, KWLoc)) {
+      Diag(KWLoc, getLangOpts().CPlusPlus11
+                      ? diag::warn_cxx98_compat_defaulted_function
+                      : diag::ext_defaulted_function);
       Actions.SetDeclDefaulted(Res, KWLoc);
     } else {
       llvm_unreachable("function definition after = not 'delete' or 'default'");
@@ -1158,9 +1154,9 @@ Decl *Parser::ParseFunctionDefinition(ParsingDeclarator &D,
       Diag(KWLoc, diag::err_default_delete_in_multiple_declaration)
         << Delete;
       SkipUntil(tok::semi);
-    } else {
-      ExpectAndConsume(tok::semi, diag::err_expected_semi_after,
-                       Delete ? "delete" : "default", tok::semi);
+    } else if (ExpectAndConsume(tok::semi, diag::err_expected_after,
+                                Delete ? "delete" : "default")) {
+      SkipUntil(tok::semi);
     }
 
     return Res;
@@ -2033,12 +2029,15 @@ bool BalancedDelimiterTracker::diagnoseOverflow() {
 }
 
 bool BalancedDelimiterTracker::expectAndConsume(unsigned DiagID,
-                                            const char *Msg,
-                                            tok::TokenKind SkipToToc ) {
+                                                const char *Msg,
+                                                tok::TokenKind SkipToTok) {
   LOpen = P.Tok.getLocation();
-  if (P.ExpectAndConsume(Kind, DiagID, Msg, SkipToToc))
+  if (P.ExpectAndConsume(Kind, DiagID, Msg)) {
+    if (SkipToTok != tok::unknown)
+      P.SkipUntil(SkipToTok, Parser::StopAtSemi);
     return true;
-  
+  }
+
   if (getDepth() < MaxDepth)
     return false;
     
diff --git a/clang/lib/Parse/RAIIObjectsForParser.h b/clang/lib/Parse/RAIIObjectsForParser.h
index f68a2e09fe9..711dc2a7c4d 100644
--- a/clang/lib/Parse/RAIIObjectsForParser.h
+++ b/clang/lib/Parse/RAIIObjectsForParser.h
@@ -415,8 +415,8 @@ namespace clang {
       
       return diagnoseOverflow();
     }
-    
-    bool expectAndConsume(unsigned DiagID,
+
+    bool expectAndConsume(unsigned DiagID = diag::err_expected,
                           const char *Msg = "",
                           tok::TokenKind SkipToTok = tok::unknown);
     bool consumeClose() {