Properly detect name collisions at library level

Fixing issue 592
Review URL: http://codereview.chromium.org//8724015

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@1934 260f80e4-7a28-3924-810f-c04153c831b5

runtime/vm/parser.cc

@@ -2940,6 +2940,17 @@ void Parser::ParseTopLevelVariable(TopLevel* top_level) {
     if (library_.LookupObject(var_name) != Object::null()) {
       ErrorMsg(name_pos, "'%s' is already defined", var_name.ToCString());
     }
+    String& accessor_name = String::Handle(Field::GetterName(var_name));
+    if (library_.LookupObject(accessor_name) != Object::null()) {
+      ErrorMsg(name_pos, "getter for '%s' is already defined",
+               var_name.ToCString());
+    }
+    accessor_name = Field::SetterName(var_name);
+    if (library_.LookupObject(accessor_name) != Object::null()) {
+      ErrorMsg(name_pos, "setter for '%s' is already defined",
+               var_name.ToCString());
+    }
+
     Field& field = Field::ZoneHandle(
         Field::New(var_name, is_static, is_final, name_pos));
     field.set_type(type);
@@ -2992,6 +3003,16 @@ void Parser::ParseTopLevelFunction(TopLevel* top_level) {
   if (library_.LookupObject(func_name) != Object::null()) {
     ErrorMsg(name_pos, "'%s' is already defined", func_name.ToCString());
   }
+  String& accessor_name = String::Handle(Field::GetterName(func_name));
+  if (library_.LookupObject(accessor_name) != Object::null()) {
+    ErrorMsg(name_pos, "'%s' is already defined as getter",
+             func_name.ToCString());
+  }
+  accessor_name = Field::SetterName(func_name);
+  if (library_.LookupObject(accessor_name) != Object::null()) {
+    ErrorMsg(name_pos, "'%s' is already defined as setter",
+             func_name.ToCString());
+  }
 
   if (CurrentToken() != Token::kLPAREN) {
     ErrorMsg("'(' expected");
@@ -3069,6 +3090,16 @@ void Parser::ParseTopLevelAccessor(TopLevel* top_level) {
              is_getter ? "getter" : "setter");
   }
 
+  if (library_.LookupObject(*field_name) != Object::null()) {
+    ErrorMsg(name_pos, "'%s' is already defined in this library",
+             field_name->ToCString());
+  }
+  if (library_.LookupObject(accessor_name) != Object::null()) {
+    ErrorMsg(name_pos, "%s for '%s' is already defined",
+             is_getter ? "getter" : "setter",
+             field_name->ToCString());
+  }
+
   if (CurrentToken() == Token::kLBRACE) {
     SkipBlock();
   } else if (CurrentToken() == Token::kARROW) {

tests/language/src/ToplevelCollision1Test.dart

@@ -0,0 +1,15 @@
+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+int x = 100;
+
+get x() => 200;                 /// 00: compile-time error
+set x(var i) { print(i); }      /// 01: compile-time error
+
+int x(a, b) { print(a + b); }   /// 02: compile-time error
+
+
+void main() {
+  // No need to reference x.
+}

tests/language/src/ToplevelCollision2Test.dart

@@ -0,0 +1,21 @@
+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+
+get x() => 200;
+
+// Ok: can have a setter named x when getter x is defined.
+set x(var i) { print(i); }
+
+// Error: there is already a getter for x
+int x;                          /// 00: compile-time error
+
+// Error: there is already a getter named x.
+int x(a, b) { print(a + b); }   /// 01: compile-time error
+
+
+
+void main() {
+  // No need to reference x.
+}