Improve code completion in failure cases in two ways:
  1) Suppress diagnostics as soon as we form the code-completion
  token, so we don't get any error/warning spew from the early
  end-of-file.
  2) If we consume a code-completion token when we weren't expecting
  one, go into a code-completion recovery path that produces the best
  results it can based on the context that the parser is in.





git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@104585 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index e7650ea..3e7d4a1 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -839,7 +839,7 @@
       CCC = Action::CCC_ObjCImplementation;
     
     Actions.CodeCompleteOrdinaryName(CurScope, CCC);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
   
   DS.SetRangeStart(Tok.getLocation());
@@ -1870,7 +1870,7 @@
   if (Tok.is(tok::code_completion)) {
     // Code completion for an enum name.
     Actions.CodeCompleteTag(CurScope, DeclSpec::TST_enum);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
   
   llvm::OwningPtr<AttributeList> Attr;
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index b276db6..479c04c 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -50,7 +50,7 @@
 
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteNamespaceDecl(CurScope);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   SourceLocation IdentLoc;
@@ -136,7 +136,7 @@
 
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteNamespaceAliasDecl(CurScope);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   CXXScopeSpec SS;
@@ -231,7 +231,7 @@
 
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteUsing(CurScope);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   if (Tok.is(tok::kw_namespace))
@@ -268,7 +268,7 @@
 
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteUsingDirective(CurScope);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   CXXScopeSpec SS;
@@ -610,7 +610,7 @@
   if (Tok.is(tok::code_completion)) {
     // Code completion for a struct, class, or union name.
     Actions.CodeCompleteTag(CurScope, TagType);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   AttributeList *AttrList = 0;
diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index ed27f3b..b036e56 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -222,7 +222,7 @@
 Parser::OwningExprResult Parser::ParseAssignmentExpression() {
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteOrdinaryName(CurScope, Action::CCC_Expression);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   if (Tok.is(tok::kw_throw))
@@ -906,7 +906,7 @@
     return ParsePostfixExpressionSuffix(ParseBlockLiteralExpression());
   case tok::code_completion:
     Actions.CodeCompleteOrdinaryName(CurScope, Action::CCC_Expression);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
     return ParseCastExpression(isUnaryExpression, isAddressOfOperand, 
                                NotCastExpr, TypeOfCast);
   case tok::l_square:
@@ -975,7 +975,7 @@
 
       if (Tok.is(tok::code_completion)) {
         Actions.CodeCompleteCall(CurScope, LHS.get(), 0, 0);
-        ConsumeToken();
+        ConsumeCodeCompletionToken();
       }
       
       if (Tok.isNot(tok::r_paren)) {
@@ -1029,7 +1029,7 @@
         Actions.CodeCompleteMemberReferenceExpr(CurScope, LHS.get(),
                                                 OpLoc, OpKind == tok::arrow);
         
-        ConsumeToken();
+        ConsumeCodeCompletionToken();
       }
       
       if (MayBePseudoDestructor) {
@@ -1562,7 +1562,7 @@
     if (Tok.is(tok::code_completion)) {
       if (Completer)
         (Actions.*Completer)(CurScope, Data, Exprs.data(), Exprs.size());
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
     
     OwningExprResult Expr(ParseAssignmentExpression());
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index 0a909f6..46f1d94 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -110,7 +110,7 @@
         // Code completion for a nested-name-specifier, where the code
         // code completion token follows the '::'.
         Actions.CodeCompleteQualifiedId(CurScope, SS, EnteringContext);
-        ConsumeToken();
+        ConsumeCodeCompletionToken();
       }
     }
 
@@ -729,7 +729,7 @@
                                bool ConvertToBoolean) {
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteOrdinaryName(CurScope, Action::CCC_Condition);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   if (!isCXXConditionDeclaration()) {
@@ -1274,7 +1274,7 @@
       Actions.CodeCompleteOperatorName(CurScope);
       
       // Consume the operator token.
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
       
       // Don't try to parse any further.
       return true;
diff --git a/lib/Parse/ParseObjc.cpp b/lib/Parse/ParseObjc.cpp
index 9acb4fe..9cfe734 100644
--- a/lib/Parse/ParseObjc.cpp
+++ b/lib/Parse/ParseObjc.cpp
@@ -32,7 +32,7 @@
 
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteObjCAtDirective(CurScope, ObjCImpDecl, false);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   switch (Tok.getObjCKeywordID()) {
@@ -131,7 +131,7 @@
   // Code completion after '@interface'.
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteObjCInterfaceDecl(CurScope);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   if (Tok.isNot(tok::identifier)) {
@@ -149,7 +149,7 @@
     IdentifierInfo *categoryId = 0;
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteObjCInterfaceCategory(CurScope, nameId, nameLoc);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
     
     // For ObjC2, the category name is optional (not an error).
@@ -204,7 +204,7 @@
     // Code completion of superclass names.
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteObjCSuperclass(CurScope, nameId, nameLoc);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
 
     if (Tok.isNot(tok::identifier)) {
@@ -350,7 +350,7 @@
       Actions.CodeCompleteOrdinaryName(CurScope, 
                                   ObjCImpDecl? Action::CCC_ObjCImplementation
                                              : Action::CCC_ObjCInterface);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
     
     // If we don't have an @ directive, parse it as a function definition.
@@ -371,7 +371,7 @@
     SourceLocation AtLoc = ConsumeToken(); // the "@"
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteObjCAtDirective(CurScope, ObjCImpDecl, true);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
       break;
     }
 
@@ -438,7 +438,7 @@
   // EOF.  In the former case, eat the @end.  In the later case, emit an error.
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteObjCAtDirective(CurScope, ObjCImpDecl, true);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   } else if (Tok.isObjCAtKeyword(tok::objc_end))
     ConsumeToken(); // the "end" identifier
   else
@@ -477,7 +477,7 @@
   while (1) {
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteObjCPropertyFlags(CurScope, DS);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
     const IdentifierInfo *II = Tok.getIdentifierInfo();
 
@@ -514,7 +514,7 @@
         else
           Actions.CodeCompleteObjCPropertyGetter(CurScope, ClassDecl,
                                                  Methods, NumMethods);
-        ConsumeToken();
+        ConsumeCodeCompletionToken();
       }
 
       if (Tok.isNot(tok::identifier)) {
@@ -782,7 +782,7 @@
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteObjCMethodDecl(CurScope, mType == tok::minus, 
                                        /*ReturnType=*/0, IDecl);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   // Parse the return type if present.
@@ -799,7 +799,7 @@
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteObjCMethodDecl(CurScope, mType == tok::minus, 
                                        ReturnType, IDecl);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   // Now parse the selector.
@@ -945,7 +945,7 @@
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteObjCProtocolReferences(ProtocolIdents.data(), 
                                                  ProtocolIdents.size());
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
 
     if (Tok.isNot(tok::identifier)) {
@@ -1026,7 +1026,7 @@
       
       if (Tok.is(tok::code_completion)) {
         Actions.CodeCompleteObjCAtVisibility(CurScope);
-        ConsumeToken();
+        ConsumeCodeCompletionToken();
       }
       
       switch (Tok.getObjCKeywordID()) {
@@ -1046,7 +1046,7 @@
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteOrdinaryName(CurScope, 
                                        Action::CCC_ObjCInstanceVariableList);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
     
     struct ObjCIvarCallback : FieldCallback {
@@ -1117,7 +1117,7 @@
 
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteObjCProtocolDecl(CurScope);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   if (Tok.isNot(tok::identifier)) {
@@ -1203,7 +1203,7 @@
   // Code completion after '@implementation'.
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteObjCImplementationDecl(CurScope);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
 
   if (Tok.isNot(tok::identifier)) {
@@ -1222,7 +1222,7 @@
 
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteObjCImplementationCategory(CurScope, nameId, nameLoc);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
     
     if (Tok.is(tok::identifier)) {
@@ -1342,7 +1342,7 @@
   while (true) {
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteObjCPropertyDefinition(CurScope, ObjCImpDecl);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
     
     if (Tok.isNot(tok::identifier)) {
@@ -1361,7 +1361,7 @@
       if (Tok.is(tok::code_completion)) {
         Actions.CodeCompleteObjCPropertySynthesizeIvar(CurScope, propertyId,
                                                        ObjCImpDecl);
-        ConsumeToken();
+        ConsumeCodeCompletionToken();
       }
       
       if (Tok.isNot(tok::identifier)) {
@@ -1400,7 +1400,7 @@
   while (true) {
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteObjCPropertyDefinition(CurScope, ObjCImpDecl);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
     
     if (Tok.isNot(tok::identifier)) {
@@ -1654,7 +1654,7 @@
 Parser::OwningStmtResult Parser::ParseObjCAtStatement(SourceLocation AtLoc) {
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteObjCAtStatement(CurScope);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
     return StmtError();
   }
   
@@ -1685,7 +1685,7 @@
   switch (Tok.getKind()) {
   case tok::code_completion:
     Actions.CodeCompleteObjCAtExpression(CurScope);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
     return ExprError();
 
   case tok::string_literal:    // primary-expression: string-literal
@@ -1925,7 +1925,7 @@
     else
       Actions.CodeCompleteObjCInstanceMessage(CurScope, ReceiverExpr.get(), 
                                               0, 0);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
   
   // Parse objc-selector
@@ -1979,7 +1979,7 @@
           Actions.CodeCompleteObjCInstanceMessage(CurScope, ReceiverExpr.get(),
                                                   KeyIdents.data(), 
                                                   KeyIdents.size());
-        ConsumeToken();
+        ConsumeCodeCompletionToken();
       }
             
       // Check for another keyword selector.
diff --git a/lib/Parse/ParseStmt.cpp b/lib/Parse/ParseStmt.cpp
index ea364ee..98c0058 100644
--- a/lib/Parse/ParseStmt.cpp
+++ b/lib/Parse/ParseStmt.cpp
@@ -283,7 +283,7 @@
 
     if (Tok.is(tok::code_completion)) {
       Actions.CodeCompleteCase(CurScope);
-      ConsumeToken();
+      ConsumeCodeCompletionToken();
     }
     
     /// We don't want to treat 'case x : y' as a potential typo for 'case x::y'.
@@ -1000,7 +1000,7 @@
     Actions.CodeCompleteOrdinaryName(CurScope, 
                                      C99orCXXorObjC? Action::CCC_ForInit
                                                    : Action::CCC_Expression);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
   }
   
   // Parse the first part of the for specifier.
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index 37475d2..8407db1 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -134,7 +134,7 @@
 /// returned.
 bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID,
                               const char *Msg, tok::TokenKind SkipToTok) {
-  if (Tok.is(ExpectedTok)) {
+  if (Tok.is(ExpectedTok) || Tok.is(tok::code_completion)) {
     ConsumeAnyToken();
     return false;
   }
@@ -189,7 +189,11 @@
     case tok::eof:
       // Ran out of tokens.
       return false;
-
+        
+    case tok::code_completion:
+      ConsumeToken();
+      return false;
+        
     case tok::l_paren:
       // Recursively skip properly-nested parens.
       ConsumeParen();
@@ -447,7 +451,7 @@
       Actions.CodeCompleteOrdinaryName(CurScope, 
                                    ObjCImpDecl? Action::CCC_ObjCImplementation
                                               : Action::CCC_Namespace);
-    ConsumeToken();
+    ConsumeCodeCompletionToken();
     return ParseExternalDeclaration(Attr);
   case tok::kw_using:
   case tok::kw_namespace:
@@ -1072,6 +1076,22 @@
   return false;
 }
 
+void Parser::CodeCompletionRecovery() {
+  for (Scope *S = CurScope; S; S = S->getParent()) {
+    if (S->getFlags() & Scope::FnScope) {
+      Actions.CodeCompleteOrdinaryName(CurScope, Action::CCC_RecoveryInFunction);
+      return;
+    }
+    
+    if (S->getFlags() & Scope::ClassScope) {
+      Actions.CodeCompleteOrdinaryName(CurScope, Action::CCC_Class);
+      return;
+    }
+  }
+  
+  Actions.CodeCompleteOrdinaryName(CurScope, Action::CCC_Namespace);
+}
+
 // Anchor the Parser::FieldCallback vtable to this translation unit.
 // We use a spurious method instead of the destructor because
 // destroying FieldCallbacks can actually be slightly