Cut off parsing early during code completion

These calls to ConsumeCodeCompletionToken() caused parsing to continue
needlessly when an immediate cutOffParsing() would do.

Document the function to clarify its correct usage.

llvm-svn: 207823

clang/include/clang/Parse/Parser.h

@@ -419,8 +419,9 @@ private:
 
   /// \brief Consume the current code-completion token.
   ///
-  /// This routine should be called to consume the code-completion token once
+  /// This routine can be called to consume the code-completion token and
-  /// a code-completion action has already been invoked.
+  /// continue processing in special cases where \c cutOffParsing() isn't
+  /// desired, such as token caching or completion with lookahead.
   SourceLocation ConsumeCodeCompletionToken() {
     assert(Tok.is(tok::code_completion));
     PrevTokLocation = Tok.getLocation();

clang/lib/Parse/ParseExprCXX.cpp

@@ -767,7 +767,7 @@ Optional<unsigned> Parser::ParseLambdaIntroducer(LambdaIntroducer &Intro,
               !Intro.Captures.empty())) {
           Actions.CodeCompleteLambdaIntroducer(getCurScope(), Intro, 
                                                /*AfterAmpersand=*/false);
-          ConsumeCodeCompletionToken();
+          cutOffParsing();
           break;
         }
 
@@ -784,7 +784,7 @@ Optional<unsigned> Parser::ParseLambdaIntroducer(LambdaIntroducer &Intro,
       else
         Actions.CodeCompleteLambdaIntroducer(getCurScope(), Intro, 
                                              /*AfterAmpersand=*/false);
-      ConsumeCodeCompletionToken();
+      cutOffParsing();
       break;
     }
 
@@ -808,7 +808,7 @@ Optional<unsigned> Parser::ParseLambdaIntroducer(LambdaIntroducer &Intro,
         if (Tok.is(tok::code_completion)) {
           Actions.CodeCompleteLambdaIntroducer(getCurScope(), Intro, 
                                                /*AfterAmpersand=*/true);
-          ConsumeCodeCompletionToken();
+          cutOffParsing();
           break;
         }
       }

clang/lib/Parse/Parser.cpp

@@ -1896,8 +1896,7 @@ Parser::DeclGroupPtrTy Parser::ParseModuleImport(SourceLocation AtLoc) {
     if (!Tok.is(tok::identifier)) {
       if (Tok.is(tok::code_completion)) {
         Actions.CodeCompleteModuleImport(ImportLoc, Path);
-        ConsumeCodeCompletionToken();
+        cutOffParsing();
-        SkipUntil(tok::semi);
         return DeclGroupPtrTy();
       }