Don't dynamically scope GN templates.

tools/gn/functions_unittest.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "tools/gn/functions.h"
+#include "tools/gn/parse_tree.h"
+#include "tools/gn/test_with_scope.h"
+#include "tools/gn/value.h"
+
+TEST(Functions, Defined) {
+  TestWithScope setup;
+
+  //InputFile input_file(SourceFile("//foo"));
+  FunctionCallNode function_call;
+  Err err;
+
+  // Test an undefined identifier.
+  Token undefined_token(Location(), Token::IDENTIFIER, "undef");
+  ListNode args_list_identifier_undefined;
+  args_list_identifier_undefined.append_item(
+      scoped_ptr<ParseNode>(new IdentifierNode(undefined_token)));
+  Value result = functions::RunDefined(setup.scope(), &function_call,
+                                       &args_list_identifier_undefined, &err);
+  ASSERT_EQ(Value::BOOLEAN, result.type());
+  EXPECT_FALSE(result.boolean_value());
+
+  // Define a value that's itself a scope value.
+  const char kDef[] = "def";  // Defined variable name.
+  Scope nested(setup.scope());
+  setup.scope()->SetValue(kDef, Value(NULL, &nested), NULL);
+
+  // Test the defined identifier.
+  Token defined_token(Location(), Token::IDENTIFIER, kDef);
+  ListNode args_list_identifier_defined;
+  args_list_identifier_defined.append_item(
+      scoped_ptr<ParseNode>(new IdentifierNode(defined_token)));
+  result = functions::RunDefined(setup.scope(), &function_call,
+                                 &args_list_identifier_defined, &err);
+  ASSERT_EQ(Value::BOOLEAN, result.type());
+  EXPECT_TRUE(result.boolean_value());
+
+  // Should also work by passing an accessor node so you can do
+  // "defined(def.foo)" to see if foo is defined on the def scope.
+  scoped_ptr<AccessorNode> undef_accessor(new AccessorNode);
+  undef_accessor->set_base(defined_token);
+  undef_accessor->set_member(scoped_ptr<IdentifierNode>(
+      new IdentifierNode(undefined_token)));
+  ListNode args_list_accessor_defined;
+  args_list_accessor_defined.append_item(undef_accessor.PassAs<ParseNode>());
+  result = functions::RunDefined(setup.scope(), &function_call,
+                                 &args_list_accessor_defined, &err);
+  ASSERT_EQ(Value::BOOLEAN, result.type());
+  EXPECT_FALSE(result.boolean_value());
+}