vendor/clang/clang-trunk-r338150

1 files changed, 259 insertions, 124 deletions

diff --git a/lib/Parse/ParseTemplate.cpp b/lib/Parse/ParseTemplate.cpp
index 56a16b9e02711..f7a69c482e17a 100644
--- a/lib/Parse/ParseTemplate.cpp
+++ b/lib/Parse/ParseTemplate.cpp
@@ -21,27 +21,22 @@
 #include "clang/Sema/Scope.h"
 using namespace clang;
 
-/// \brief Parse a template declaration, explicit instantiation, or
+/// Parse a template declaration, explicit instantiation, or
 /// explicit specialization.
-Decl *
-Parser::ParseDeclarationStartingWithTemplate(unsigned Context,
-                                             SourceLocation &DeclEnd,
-                                             AccessSpecifier AS,
-                                             AttributeList *AccessAttrs) {
+Decl *Parser::ParseDeclarationStartingWithTemplate(
+    DeclaratorContext Context, SourceLocation &DeclEnd,
+    ParsedAttributes &AccessAttrs, AccessSpecifier AS) {
   ObjCDeclContextSwitch ObjCDC(*this);
   
   if (Tok.is(tok::kw_template) && NextToken().isNot(tok::less)) {
-    return ParseExplicitInstantiation(Context,
-                                      SourceLocation(), ConsumeToken(),
-                                      DeclEnd, AS);
+    return ParseExplicitInstantiation(Context, SourceLocation(), ConsumeToken(),
+                                      DeclEnd, AccessAttrs, AS);
   }
-  return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AS,
-                                                  AccessAttrs);
+  return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AccessAttrs,
+                                                  AS);
 }
 
-
-
-/// \brief Parse a template declaration or an explicit specialization.
+/// Parse a template declaration or an explicit specialization.
 ///
 /// Template declarations include one or more template parameter lists
 /// and either the function or class template declaration. Explicit
@@ -56,11 +51,9 @@ Parser::ParseDeclarationStartingWithTemplate(unsigned Context,
 ///
 ///       explicit-specialization: [ C++ temp.expl.spec]
 ///         'template' '<' '>' declaration
-Decl *
-Parser::ParseTemplateDeclarationOrSpecialization(unsigned Context,
-                                                 SourceLocation &DeclEnd,
-                                                 AccessSpecifier AS,
-                                                 AttributeList *AccessAttrs) {
+Decl *Parser::ParseTemplateDeclarationOrSpecialization(
+    DeclaratorContext Context, SourceLocation &DeclEnd,
+    ParsedAttributes &AccessAttrs, AccessSpecifier AS) {
   assert(Tok.isOneOf(tok::kw_export, tok::kw_template) &&
          "Token does not start a template declaration.");
 
@@ -149,15 +142,13 @@ Parser::ParseTemplateDeclarationOrSpecialization(unsigned Context,
   ParseScopeFlags TemplateScopeFlags(this, NewFlags, isSpecialization);
 
   // Parse the actual template declaration.
-  return ParseSingleDeclarationAfterTemplate(Context,
-                                             ParsedTemplateInfo(&ParamLists,
-                                                             isSpecialization,
-                                                         LastParamListWasEmpty),
-                                             ParsingTemplateParams,
-                                             DeclEnd, AS, AccessAttrs);
+  return ParseSingleDeclarationAfterTemplate(
+      Context,
+      ParsedTemplateInfo(&ParamLists, isSpecialization, LastParamListWasEmpty),
+      ParsingTemplateParams, DeclEnd, AccessAttrs, AS);
 }
 
-/// \brief Parse a single declaration that declares a template,
+/// Parse a single declaration that declares a template,
 /// template specialization, or explicit instantiation of a template.
 ///
 /// \param DeclEnd will receive the source location of the last token
@@ -167,14 +158,10 @@ Parser::ParseTemplateDeclarationOrSpecialization(unsigned Context,
 /// declaration. Will be AS_none for namespace-scope declarations.
 ///
 /// \returns the new declaration.
-Decl *
-Parser::ParseSingleDeclarationAfterTemplate(
-                                       unsigned Context,
-                                       const ParsedTemplateInfo &TemplateInfo,
-                                       ParsingDeclRAIIObject &DiagsFromTParams,
-                                       SourceLocation &DeclEnd,
-                                       AccessSpecifier AS,
-                                       AttributeList *AccessAttrs) {
+Decl *Parser::ParseSingleDeclarationAfterTemplate(
+    DeclaratorContext Context, const ParsedTemplateInfo &TemplateInfo,
+    ParsingDeclRAIIObject &DiagsFromTParams, SourceLocation &DeclEnd,
+    ParsedAttributes &AccessAttrs, AccessSpecifier AS) {
   assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
          "Template information required");
 
@@ -186,7 +173,7 @@ Parser::ParseSingleDeclarationAfterTemplate(
     return ParseStaticAssertDeclaration(DeclEnd);
   }
 
-  if (Context == Declarator::MemberContext) {
+  if (Context == DeclaratorContext::MemberContext) {
     // We are parsing a member template.
     ParseCXXClassMemberDeclaration(AS, AccessAttrs, TemplateInfo,
                                    &DiagsFromTParams);
@@ -234,7 +221,7 @@ Parser::ParseSingleDeclarationAfterTemplate(
     DS.takeAttributesFrom(prefixAttrs);
 
   // Parse the declarator.
-  ParsingDeclarator DeclaratorInfo(*this, DS, (Declarator::TheContext)Context);
+  ParsingDeclarator DeclaratorInfo(*this, DS, (DeclaratorContext)Context);
   ParseDeclarator(DeclaratorInfo);
   // Error parsing the declarator?
   if (!DeclaratorInfo.hasName()) {
@@ -255,7 +242,7 @@ Parser::ParseSingleDeclarationAfterTemplate(
     // Function definitions are only allowed at file scope and in C++ classes.
     // The C++ inline method definition case is handled elsewhere, so we only
     // need to handle the file scope definition case.
-    if (Context != Declarator::FileContext) {
+    if (Context != DeclaratorContext::FileContext) {
       Diag(Tok, diag::err_function_definition_not_allowed);
       SkipMalformedDecl();
       return nullptr;
@@ -271,7 +258,8 @@ Parser::ParseSingleDeclarationAfterTemplate(
     }
 
     if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation) {
-      if (DeclaratorInfo.getName().getKind() != UnqualifiedId::IK_TemplateId) {
+      if (DeclaratorInfo.getName().getKind() !=
+          UnqualifiedIdKind::IK_TemplateId) {
         // If the declarator-id is not a template-id, issue a diagnostic and
         // recover by ignoring the 'template' keyword.
         Diag(Tok, diag::err_template_defn_explicit_instantiation) << 0;
@@ -369,7 +357,7 @@ bool Parser::ParseTemplateParameters(
 ///         template-parameter
 ///         template-parameter-list ',' template-parameter
 bool
-Parser::ParseTemplateParameterList(unsigned Depth,
+Parser::ParseTemplateParameterList(const unsigned Depth,
                              SmallVectorImpl<NamedDecl*> &TemplateParams) {
   while (1) {
     
@@ -402,7 +390,7 @@ Parser::ParseTemplateParameterList(unsigned Depth,
   return true;
 }
 
-/// \brief Determine whether the parser is at the start of a template
+/// Determine whether the parser is at the start of a template
 /// type parameter.
 bool Parser::isStartOfTemplateTypeParameter() {
   if (Tok.is(tok::kw_class)) {
@@ -487,6 +475,20 @@ NamedDecl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) {
   if (Tok.is(tok::kw_template))
     return ParseTemplateTemplateParameter(Depth, Position);
 
+  // Is there just a typo in the input code? ('typedef' instead of 'typename')
+  if (Tok.is(tok::kw_typedef)) {
+    Diag(Tok.getLocation(), diag::err_expected_template_parameter);
+
+    Diag(Tok.getLocation(), diag::note_meant_to_use_typename)
+        << FixItHint::CreateReplacement(CharSourceRange::getCharRange(
+                                            Tok.getLocation(), Tok.getEndLoc()),
+                                        "typename");
+
+    Tok.setKind(tok::kw_typename);
+
+    return ParseTypeParameter(Depth, Position);
+  }
+
   // If it's none of the above, then it must be a parameter declaration.
   // NOTE: This will pick up errors in the closure of the template parameter
   // list (e.g., template < ; Check here to implement >> style closures.
@@ -546,7 +548,7 @@ NamedDecl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
   ParsedType DefaultArg;
   if (TryConsumeToken(tok::equal, EqualLoc))
     DefaultArg = ParseTypeName(/*Range=*/nullptr,
-                               Declarator::TemplateTypeArgContext).get();
+                               DeclaratorContext::TemplateTypeArgContext).get();
 
   return Actions.ActOnTypeParameter(getCurScope(), TypenameKeyword, EllipsisLoc,
                                     KeyLoc, ParamName, NameLoc, Depth, Position,
@@ -676,10 +678,10 @@ Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) {
   // declarators (parts of declarators?) are accepted for parameters.
   DeclSpec DS(AttrFactory);
   ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS_none,
-                             DSC_template_param);
+                             DeclSpecContext::DSC_template_param);
 
   // Parse this as a typename.
-  Declarator ParamDecl(DS, Declarator::TemplateParamContext);
+  Declarator ParamDecl(DS, DeclaratorContext::TemplateParamContext);
   ParseDeclarator(ParamDecl);
   if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) {
     Diag(Tok.getLocation(), diag::err_expected_template_parameter);
@@ -739,7 +741,7 @@ void Parser::DiagnoseMisplacedEllipsisInDeclarator(SourceLocation EllipsisLoc,
                             AlreadyHasEllipsis, D.hasName());
 }
 
-/// \brief Parses a '>' at the end of a template list.
+/// Parses a '>' at the end of a template list.
 ///
 /// If this function encounters '>>', '>>>', '>=', or '>>=', it tries
 /// to determine if these tokens were supposed to be a '>' followed by
@@ -760,6 +762,7 @@ bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
   // What will be left once we've consumed the '>'.
   tok::TokenKind RemainingToken;
   const char *ReplacementStr = "> >";
+  bool MergeWithNextToken = false;
 
   switch (Tok.getKind()) {
   default:
@@ -785,6 +788,15 @@ bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
   case tok::greaterequal:
     RemainingToken = tok::equal;
     ReplacementStr = "> =";
+
+    // Join two adjacent '=' tokens into one, for cases like:
+    //   void (*p)() = f<int>;
+    //   return f<int>==p;
+    if (NextToken().is(tok::equal) &&
+        areTokensAdjacent(Tok, NextToken())) {
+      RemainingToken = tok::equalequal;
+      MergeWithNextToken = true;
+    }
     break;
 
   case tok::greatergreaterequal:
@@ -792,22 +804,35 @@ bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
     break;
   }
 
-  // This template-id is terminated by a token which starts with a '>'. Outside
-  // C++11, this is now error recovery, and in C++11, this is error recovery if
-  // the token isn't '>>' or '>>>'.
-  // '>>>' is for CUDA, where this sequence of characters is parsed into
-  // tok::greatergreatergreater, rather than two separate tokens.
+  // This template-id is terminated by a token that starts with a '>'.
+  // Outside C++11 and Objective-C, this is now error recovery.
+  //
+  // C++11 allows this when the token is '>>', and in CUDA + C++11 mode, we
+  // extend that treatment to also apply to the '>>>' token.
   //
-  // We always allow this for Objective-C type parameter and type argument
-  // lists.
-  RAngleLoc = Tok.getLocation();
+  // Objective-C allows this in its type parameter / argument lists.
+
+  SourceLocation TokBeforeGreaterLoc = PrevTokLocation;
+  SourceLocation TokLoc = Tok.getLocation();
   Token Next = NextToken();
+
+  // Whether splitting the current token after the '>' would undesirably result
+  // in the remaining token pasting with the token after it. This excludes the
+  // MergeWithNextToken cases, which we've already handled.
+  bool PreventMergeWithNextToken =
+      (RemainingToken == tok::greater ||
+       RemainingToken == tok::greatergreater) &&
+      (Next.isOneOf(tok::greater, tok::greatergreater,
+                    tok::greatergreatergreater, tok::equal, tok::greaterequal,
+                    tok::greatergreaterequal, tok::equalequal)) &&
+      areTokensAdjacent(Tok, Next);
+
+  // Diagnose this situation as appropriate.
   if (!ObjCGenericList) {
-    // The source range of the '>>' or '>=' at the start of the token.
-    CharSourceRange ReplacementRange =
-        CharSourceRange::getCharRange(RAngleLoc,
-            Lexer::AdvanceToTokenCharacter(RAngleLoc, 2, PP.getSourceManager(),
-                                           getLangOpts()));
+    // The source range of the replaced token(s).
+    CharSourceRange ReplacementRange = CharSourceRange::getCharRange(
+        TokLoc, Lexer::AdvanceToTokenCharacter(TokLoc, 2, PP.getSourceManager(),
+                                               getLangOpts()));
 
     // A hint to put a space between the '>>'s. In order to make the hint as
     // clear as possible, we include the characters either side of the space in
@@ -818,13 +843,7 @@ bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
     // A hint to put another space after the token, if it would otherwise be
     // lexed differently.
     FixItHint Hint2;
-    if ((RemainingToken == tok::greater ||
-         RemainingToken == tok::greatergreater) &&
-        (Next.isOneOf(tok::greater, tok::greatergreater,
-                      tok::greatergreatergreater, tok::equal,
-                      tok::greaterequal, tok::greatergreaterequal,
-                      tok::equalequal)) &&
-        areTokensAdjacent(Tok, Next))
+    if (PreventMergeWithNextToken)
       Hint2 = FixItHint::CreateInsertion(Next.getLocation(), " ");
 
     unsigned DiagId = diag::err_two_right_angle_brackets_need_space;
@@ -833,55 +852,68 @@ bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
       DiagId = diag::warn_cxx98_compat_two_right_angle_brackets;
     else if (Tok.is(tok::greaterequal))
       DiagId = diag::err_right_angle_bracket_equal_needs_space;
-    Diag(Tok.getLocation(), DiagId) << Hint1 << Hint2;
+    Diag(TokLoc, DiagId) << Hint1 << Hint2;
   }
 
+  // Find the "length" of the resulting '>' token. This is not always 1, as it
+  // can contain escaped newlines.
+  unsigned GreaterLength = Lexer::getTokenPrefixLength(
+      TokLoc, 1, PP.getSourceManager(), getLangOpts());
+
+  // Annotate the source buffer to indicate that we split the token after the
+  // '>'. This allows us to properly find the end of, and extract the spelling
+  // of, the '>' token later.
+  RAngleLoc = PP.SplitToken(TokLoc, GreaterLength);
+
   // Strip the initial '>' from the token.
-  Token PrevTok = Tok;
-  if (RemainingToken == tok::equal && Next.is(tok::equal) &&
-      areTokensAdjacent(Tok, Next)) {
-    // Join two adjacent '=' tokens into one, for cases like:
-    //   void (*p)() = f<int>;
-    //   return f<int>==p;
+  bool CachingTokens = PP.IsPreviousCachedToken(Tok);
+
+  Token Greater = Tok;
+  Greater.setLocation(RAngleLoc);
+  Greater.setKind(tok::greater);
+  Greater.setLength(GreaterLength);
+
+  unsigned OldLength = Tok.getLength();
+  if (MergeWithNextToken) {
     ConsumeToken();
-    Tok.setKind(tok::equalequal);
-    Tok.setLength(Tok.getLength() + 1);
-  } else {
-    Tok.setKind(RemainingToken);
-    Tok.setLength(Tok.getLength() - 1);
+    OldLength += Tok.getLength();
   }
-  Tok.setLocation(Lexer::AdvanceToTokenCharacter(RAngleLoc, 1,
-                                                 PP.getSourceManager(),
-                                                 getLangOpts()));
-
-  // The advance from '>>' to '>' in a ObjectiveC template argument list needs
-  // to be properly reflected in the token cache to allow correct interaction
-  // between annotation and backtracking.
-  if (ObjCGenericList && PrevTok.getKind() == tok::greatergreater &&
-      RemainingToken == tok::greater && PP.IsPreviousCachedToken(PrevTok)) {
-    PrevTok.setKind(RemainingToken);
-    PrevTok.setLength(1);
-    // Break tok::greatergreater into two tok::greater but only add the second
-    // one in case the client asks to consume the last token.
+
+  Tok.setKind(RemainingToken);
+  Tok.setLength(OldLength - GreaterLength);
+
+  // Split the second token if lexing it normally would lex a different token
+  // (eg, the fifth token in 'A<B>>>' should re-lex as '>', not '>>').
+  SourceLocation AfterGreaterLoc = TokLoc.getLocWithOffset(GreaterLength);
+  if (PreventMergeWithNextToken)
+    AfterGreaterLoc = PP.SplitToken(AfterGreaterLoc, Tok.getLength());
+  Tok.setLocation(AfterGreaterLoc);
+
+  // Update the token cache to match what we just did if necessary.
+  if (CachingTokens) {
+    // If the previous cached token is being merged, delete it.
+    if (MergeWithNextToken)
+      PP.ReplacePreviousCachedToken({});
+
     if (ConsumeLastToken)
-      PP.ReplacePreviousCachedToken({PrevTok, Tok});
+      PP.ReplacePreviousCachedToken({Greater, Tok});
     else
-      PP.ReplacePreviousCachedToken({PrevTok});
+      PP.ReplacePreviousCachedToken({Greater});
   }
 
-  if (!ConsumeLastToken) {
-    // Since we're not supposed to consume the '>' token, we need to push
-    // this token and revert the current token back to the '>'.
+  if (ConsumeLastToken) {
+    PrevTokLocation = RAngleLoc;
+  } else {
+    PrevTokLocation = TokBeforeGreaterLoc;
     PP.EnterToken(Tok);
-    Tok.setKind(tok::greater);
-    Tok.setLength(1);
-    Tok.setLocation(RAngleLoc);
+    Tok = Greater;
   }
+
   return false;
 }
 
 
-/// \brief Parses a template-id that after the template name has
+/// Parses a template-id that after the template name has
 /// already been parsed.
 ///
 /// This routine takes care of parsing the enclosed template argument
@@ -923,7 +955,7 @@ Parser::ParseTemplateIdAfterTemplateName(bool ConsumeLastToken,
                                         /*ObjCGenericList=*/false);
 }
 
-/// \brief Replace the tokens that form a simple-template-id with an
+/// Replace the tokens that form a simple-template-id with an
 /// annotation token containing the complete template-id.
 ///
 /// The first token in the stream must be the name of a template that
@@ -1015,12 +1047,12 @@ bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK,
     Tok.setKind(tok::annot_template_id);
     
     IdentifierInfo *TemplateII =
-        TemplateName.getKind() == UnqualifiedId::IK_Identifier
+        TemplateName.getKind() == UnqualifiedIdKind::IK_Identifier
             ? TemplateName.Identifier
             : nullptr;
 
     OverloadedOperatorKind OpKind =
-        TemplateName.getKind() == UnqualifiedId::IK_Identifier
+        TemplateName.getKind() == UnqualifiedIdKind::IK_Identifier
             ? OO_None
             : TemplateName.OperatorFunctionId.Operator;
 
@@ -1044,7 +1076,7 @@ bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK,
   return false;
 }
 
-/// \brief Replaces a template-id annotation token with a type
+/// Replaces a template-id annotation token with a type
 /// annotation token.
 ///
 /// If there was a failure when forming the type from the template-id,
@@ -1089,12 +1121,12 @@ void Parser::AnnotateTemplateIdTokenAsType(bool IsClassName) {
   PP.AnnotateCachedTokens(Tok);
 }
 
-/// \brief Determine whether the given token can end a template argument.
+/// Determine whether the given token can end a template argument.
 static bool isEndOfTemplateArgument(Token Tok) {
   return Tok.isOneOf(tok::comma, tok::greater, tok::greatergreater);
 }
 
-/// \brief Parse a C++ template template argument.
+/// Parse a C++ template template argument.
 ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
   if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) &&
       !Tok.is(tok::annot_cxxscope))
@@ -1190,17 +1222,13 @@ ParsedTemplateArgument Parser::ParseTemplateArgument() {
   // argument before trying to disambiguate.
 
   EnterExpressionEvaluationContext EnterConstantEvaluated(
-      Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated);
+    Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated,
+    /*LambdaContextDecl=*/nullptr,
+    /*ExprContext=*/Sema::ExpressionEvaluationContextRecord::EK_TemplateArgument);
   if (isCXXTypeId(TypeIdAsTemplateArgument)) {
-    SourceLocation Loc = Tok.getLocation();
-    TypeResult TypeArg = ParseTypeName(/*Range=*/nullptr,
-                                       Declarator::TemplateTypeArgContext);
-    if (TypeArg.isInvalid())
-      return ParsedTemplateArgument();
-    
-    return ParsedTemplateArgument(ParsedTemplateArgument::Type,
-                                  TypeArg.get().getAsOpaquePtr(), 
-                                  Loc);
+    TypeResult TypeArg = ParseTypeName(
+        /*Range=*/nullptr, DeclaratorContext::TemplateArgContext);
+    return Actions.ActOnTemplateTypeArgument(TypeArg);
   }
   
   // Try to parse a template template argument.
@@ -1228,7 +1256,7 @@ ParsedTemplateArgument Parser::ParseTemplateArgument() {
                                 ExprArg.get(), Loc);
 }
 
-/// \brief Determine whether the current tokens can only be parsed as a 
+/// Determine whether the current tokens can only be parsed as a 
 /// template argument list (starting with the '<') and never as a '<' 
 /// expression.
 bool Parser::IsTemplateArgumentList(unsigned Skip) {
@@ -1290,27 +1318,26 @@ Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) {
   return false;
 }
 
-/// \brief Parse a C++ explicit template instantiation
+/// Parse a C++ explicit template instantiation
 /// (C++ [temp.explicit]).
 ///
 ///       explicit-instantiation:
 ///         'extern' [opt] 'template' declaration
 ///
 /// Note that the 'extern' is a GNU extension and C++11 feature.
-Decl *Parser::ParseExplicitInstantiation(unsigned Context,
+Decl *Parser::ParseExplicitInstantiation(DeclaratorContext Context,
                                          SourceLocation ExternLoc,
                                          SourceLocation TemplateLoc,
                                          SourceLocation &DeclEnd,
+                                         ParsedAttributes &AccessAttrs,
                                          AccessSpecifier AS) {
   // This isn't really required here.
   ParsingDeclRAIIObject
     ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
 
-  return ParseSingleDeclarationAfterTemplate(Context,
-                                             ParsedTemplateInfo(ExternLoc,
-                                                                TemplateLoc),
-                                             ParsingTemplateParams,
-                                             DeclEnd, AS);
+  return ParseSingleDeclarationAfterTemplate(
+      Context, ParsedTemplateInfo(ExternLoc, TemplateLoc),
+      ParsingTemplateParams, DeclEnd, AccessAttrs, AS);
 }
 
 SourceRange Parser::ParsedTemplateInfo::getSourceRange() const {
@@ -1328,7 +1355,7 @@ void Parser::LateTemplateParserCallback(void *P, LateParsedTemplate &LPT) {
   ((Parser *)P)->ParseLateTemplatedFuncDef(LPT);
 }
 
-/// \brief Late parse a C++ function template in Microsoft mode.
+/// Late parse a C++ function template in Microsoft mode.
 void Parser::ParseLateTemplatedFuncDef(LateParsedTemplate &LPT) {
   if (!LPT.D)
      return;
@@ -1419,7 +1446,7 @@ void Parser::ParseLateTemplatedFuncDef(LateParsedTemplate &LPT) {
     delete *I;
 }
 
-/// \brief Lex a delayed template function for late parsing.
+/// Lex a delayed template function for late parsing.
 void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) {
   tok::TokenKind kind = Tok.getKind();
   if (!ConsumeAndStoreFunctionPrologue(Toks)) {
@@ -1435,3 +1462,111 @@ void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) {
     }
   }
 }
+
+/// We've parsed something that could plausibly be intended to be a template
+/// name (\p LHS) followed by a '<' token, and the following code can't possibly
+/// be an expression. Determine if this is likely to be a template-id and if so,
+/// diagnose it.
+bool Parser::diagnoseUnknownTemplateId(ExprResult LHS, SourceLocation Less) {
+  TentativeParsingAction TPA(*this);
+  // FIXME: We could look at the token sequence in a lot more detail here.
+  if (SkipUntil(tok::greater, tok::greatergreater, tok::greatergreatergreater,
+                StopAtSemi | StopBeforeMatch)) {
+    TPA.Commit();
+
+    SourceLocation Greater;
+    ParseGreaterThanInTemplateList(Greater, true, false);
+    Actions.diagnoseExprIntendedAsTemplateName(getCurScope(), LHS,
+                                               Less, Greater);
+    return true;
+  }
+
+  // There's no matching '>' token, this probably isn't supposed to be
+  // interpreted as a template-id. Parse it as an (ill-formed) comparison.
+  TPA.Revert();
+  return false;
+}
+
+void Parser::checkPotentialAngleBracket(ExprResult &PotentialTemplateName) {
+  assert(Tok.is(tok::less) && "not at a potential angle bracket");
+
+  bool DependentTemplateName = false;
+  if (!Actions.mightBeIntendedToBeTemplateName(PotentialTemplateName,
+                                               DependentTemplateName))
+    return;
+
+  // OK, this might be a name that the user intended to be parsed as a
+  // template-name, followed by a '<' token. Check for some easy cases.
+
+  // If we have potential_template<>, then it's supposed to be a template-name.
+  if (NextToken().is(tok::greater) ||
+      (getLangOpts().CPlusPlus11 &&
+       NextToken().isOneOf(tok::greatergreater, tok::greatergreatergreater))) {
+    SourceLocation Less = ConsumeToken();
+    SourceLocation Greater;
+    ParseGreaterThanInTemplateList(Greater, true, false);
+    Actions.diagnoseExprIntendedAsTemplateName(
+        getCurScope(), PotentialTemplateName, Less, Greater);
+    // FIXME: Perform error recovery.
+    PotentialTemplateName = ExprError();
+    return;
+  }
+
+  // If we have 'potential_template<type-id', assume it's supposed to be a
+  // template-name if there's a matching '>' later on.
+  {
+    // FIXME: Avoid the tentative parse when NextToken() can't begin a type.
+    TentativeParsingAction TPA(*this);
+    SourceLocation Less = ConsumeToken();
+    if (isTypeIdUnambiguously() &&
+        diagnoseUnknownTemplateId(PotentialTemplateName, Less)) {
+      TPA.Commit();
+      // FIXME: Perform error recovery.
+      PotentialTemplateName = ExprError();
+      return;
+    }
+    TPA.Revert();
+  }
+
+  // Otherwise, remember that we saw this in case we see a potentially-matching
+  // '>' token later on.
+  AngleBracketTracker::Priority Priority =
+      (DependentTemplateName ? AngleBracketTracker::DependentName
+                             : AngleBracketTracker::PotentialTypo) |
+      (Tok.hasLeadingSpace() ? AngleBracketTracker::SpaceBeforeLess
+                             : AngleBracketTracker::NoSpaceBeforeLess);
+  AngleBrackets.add(*this, PotentialTemplateName.get(), Tok.getLocation(),
+                    Priority);
+}
+
+bool Parser::checkPotentialAngleBracketDelimiter(
+    const AngleBracketTracker::Loc &LAngle, const Token &OpToken) {
+  // If a comma in an expression context is followed by a type that can be a
+  // template argument and cannot be an expression, then this is ill-formed,
+  // but might be intended to be part of a template-id.
+  if (OpToken.is(tok::comma) && isTypeIdUnambiguously() &&
+      diagnoseUnknownTemplateId(LAngle.TemplateName, LAngle.LessLoc)) {
+    AngleBrackets.clear(*this);
+    return true;
+  }
+
+  // If a context that looks like a template-id is followed by '()', then
+  // this is ill-formed, but might be intended to be a template-id
+  // followed by '()'.
+  if (OpToken.is(tok::greater) && Tok.is(tok::l_paren) &&
+      NextToken().is(tok::r_paren)) {
+    Actions.diagnoseExprIntendedAsTemplateName(
+        getCurScope(), LAngle.TemplateName, LAngle.LessLoc,
+        OpToken.getLocation());
+    AngleBrackets.clear(*this);
+    return true;
+  }
+
+  // After a '>' (etc), we're no longer potentially in a construct that's
+  // intended to be treated as a template-id.
+  if (OpToken.is(tok::greater) ||
+      (getLangOpts().CPlusPlus11 &&
+       OpToken.isOneOf(tok::greatergreater, tok::greatergreatergreater)))
+    AngleBrackets.clear(*this);
+  return false;
+}