Improve parser recovery when we try to parse a call expression but the
called function itself is invalid (e.g., because of a semantic error
referring to that declaration). Fixes <rdar://problem/8044142>.

llvm-svn: 105175
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index 7be1a19..8fb71c3 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -580,7 +580,8 @@
     
       Res = ParseParenExpression(ParenExprType, false/*stopIfCastExr*/,
                                  TypeOfCast, CastTy, RParenLoc);
-      if (Res.isInvalid()) return move(Res);
+      if (Res.isInvalid()) 
+        return move(Res);
     }
 
     switch (ParenExprType) {
@@ -672,6 +673,7 @@
     Name.setIdentifier(&II, ILoc);
     Res = Actions.ActOnIdExpression(CurScope, ScopeSpec, Name, 
                                     Tok.is(tok::l_paren), false);
+
     // These can be followed by postfix-expr pieces.
     return ParsePostfixExpressionSuffix(move(Res));
   }
@@ -981,6 +983,11 @@
 
       Loc = ConsumeParen();
 
+      if (LHS.isInvalid()) {
+        SkipUntil(tok::r_paren);
+        return ExprError();
+      }
+
       if (Tok.is(tok::code_completion)) {
         Actions.CodeCompleteCall(CurScope, LHS.get(), 0, 0);
         ConsumeCodeCompletionToken();