Improve recovery (error + fix-it) when parsing type dependent template name without the "template" keyword.

For example:
   typename C1<T>:: /*template*/ Iterator<0> pos; 

Also the error is downgraded to an ExtWarn in Microsoft mode.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@128387 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 10 insertions, 4 deletions

diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index 1f41f5dbc5..385185eb3a 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -60,7 +60,8 @@ using namespace clang;
 bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
                                             ParsedType ObjectType,
                                             bool EnteringContext,
-                                            bool *MayBePseudoDestructor) {
+                                            bool *MayBePseudoDestructor,
+                                            bool IsTypename) {
   assert(getLang().CPlusPlus &&
          "Call sites of this function should be guarded by checking for C++");
 
@@ -314,12 +315,16 @@ bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
       } 
       
       if (MemberOfUnknownSpecialization && (ObjectType || SS.isSet()) && 
-          IsTemplateArgumentList(1)) {
+          (IsTypename || IsTemplateArgumentList(1))) {
         // We have something like t::getAs<T>, where getAs is a 
         // member of an unknown specialization. However, this will only
         // parse correctly as a template, so suggest the keyword 'template'
         // before 'getAs' and treat this as a dependent template name.
-        Diag(Tok.getLocation(), diag::err_missing_dependent_template_keyword)
+        unsigned DiagID = diag::err_missing_dependent_template_keyword;
+        if (getLang().Microsoft)
+          DiagID = diag::war_missing_dependent_template_keyword;
+        
+        Diag(Tok.getLocation(), DiagID)
           << II.getName()
           << FixItHint::CreateInsertion(Tok.getLocation(), "template ");
         
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index 5bf0abd6b7..c5d5ef536d 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -1037,7 +1037,8 @@ bool Parser::TryAnnotateTypeOrScopeToken(bool EnteringContext) {
     //            simple-template-id
     SourceLocation TypenameLoc = ConsumeToken();
     CXXScopeSpec SS;
-    if (ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/ParsedType(), false))
+    if (ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/ParsedType(), false,
+                                       0, /*IsTypename*/true))
       return true;
     if (!SS.isSet()) {
       Diag(Tok.getLocation(), diag::err_expected_qualified_after_typename);