Remove an overly-eager assertion when replacing tokens with an

annotation token, because some of the tokens we're annotating might
not be in the set of cached tokens (we could have consumed them
unconditionally).

Also, move the tentative parsing from ParseTemplateTemplateArgument
into the one caller that needs it, improving recovery.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86904 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Lex/PPCaching.cpp

@@ -109,6 +109,4 @@ void Preprocessor::AnnotatePreviousCachedTokens(const Token &Tok) {
       return;
     }
   }
-
-  assert(0&&"Didn't find the first token represented by the annotation token!");
 }

lib/Parse/ParseTemplate.cpp

@@ -823,15 +823,13 @@ ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
   //   A template-argument for a template template-parameter shall be the name
   //   of a class template or a template alias, expressed as id-expression.
   //   
-  // We perform some tentative parsing at this point, to determine whether
-  // we have an id-expression that refers to a class template or template
-  // alias. The grammar we tentatively parse is:
+  // We parse an id-expression that refers to a class template or template
+  // alias. The grammar we parse is:
   //
   //   nested-name-specifier[opt] template[opt] identifier
   //
   // followed by a token that terminates a template argument, such as ',', 
   // '>', or (in some cases) '>>'.
-  TentativeParsingAction TPA(*this);
   CXXScopeSpec SS; // nested-name-specifier, if present
   ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, 
                                  /*EnteringContext=*/false);
@@ -854,12 +852,10 @@ ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
         TemplateTy Template
         = Actions.ActOnDependentTemplateName(TemplateLoc, SS, Name, 
                                              /*ObjectType=*/0);
-        if (Template.get()) {
-          TPA.Commit();
+        if (Template.get())
           return ParsedTemplateArgument(SS, Template, Name.StartLocation);
       }
     } 
-    } 
   } else if (Tok.is(tok::identifier)) {
     // We may have a (non-dependent) template name.
     TemplateTy Template;
@@ -875,16 +871,12 @@ ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
       if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) {
         // We have an id-expression that refers to a class template or
         // (C++0x) template alias. 
-        TPA.Commit();
         return ParsedTemplateArgument(SS, Template, Name.StartLocation);
       }
     }
   }
   
-  // We don't have a template template argument; revert everything we have
-  // tentatively parsed.
-  TPA.Revert();
-  
+  // We don't have a template template argument.  
   return ParsedTemplateArgument();
 }
 
@@ -912,10 +904,19 @@ ParsedTemplateArgument Parser::ParseTemplateArgument() {
   }
   
   // Try to parse a template template argument.
+  {
+    TentativeParsingAction TPA(*this);
+
     ParsedTemplateArgument TemplateTemplateArgument
       = ParseTemplateTemplateArgument();
-  if (!TemplateTemplateArgument.isInvalid())
+    if (!TemplateTemplateArgument.isInvalid()) {
+      TPA.Commit();
       return TemplateTemplateArgument;
+    }
+    
+    // Revert this tentative parse to parse a non-type template argument.
+    TPA.Revert();
+  }
   
   // Parse a non-type template argument. 
   SourceLocation Loc = Tok.getLocation();

test/SemaTemplate/default-arguments.cpp

@@ -118,3 +118,6 @@ template<typename T,
 X6<int> x6a;
 X6<long> x6b; // expected-note{{while checking a default template argument}}
 X6<long, X5b> x6c;
+
+
+template<template<class> class X = B<int> > struct X7; // expected-error{{must be a class template}}