Fixes to {} handling in GN.

tools/gn/parser_unittest.cc

 // Copyright (c) 2013 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 <iostream>
 #include <sstream>
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/input_file.h"
 #include "tools/gn/parser.h"
@@ skipping 345 matching lines @@
       "        LITERAL(\"asd.cc\")\n"
       "        LITERAL(\"foo.cc\")\n"
       "     BLOCK\n"
       "      BINARY(+=)\n"
       "       IDENTIFIER(dependencies)\n"
       "       LIST\n"
       "        LITERAL(\"bar.cc\")\n";
   DoParserPrintTest(input, expected);
 }
 
-TEST(Parser, NestedBlocks) {
-  const char* input = "{cc_test(\"foo\") {{foo=1}\n{}}}";
-  const char* expected =
-      "BLOCK\n"
-      " BLOCK\n"
-      "  FUNCTION(cc_test)\n"
-      "   LIST\n"
-      "    LITERAL(\"foo\")\n"
-      "   BLOCK\n"
-      "    BLOCK\n"
-      "     BINARY(=)\n"
-      "      IDENTIFIER(foo)\n"
-      "      LITERAL(1)\n"
-      "    BLOCK\n";
-  DoParserPrintTest(input, expected);
-  const char* input_with_newline = "{cc_test(\"foo\") {{foo=1}\n{}}}";
-  DoParserPrintTest(input_with_newline, expected);
-}
-
 TEST(Parser, UnterminatedBlock) {
   DoParserErrorTest("stuff() {", 1, 9);
 }
 
 TEST(Parser, BadlyTerminatedNumber) {
   DoParserErrorTest("1234z", 1, 5);
 }
 
 TEST(Parser, NewlinesInUnusualPlaces) {
   DoParserPrintTest(
@@ skipping 303 matching lines @@
 }
 
 TEST(Parser, ConditionNoBracesElseIf) {
   DoParserErrorTest(
       "if (true) {\n"
       "  foreach(foo, []) {}\n"
       "} else if (true)\n"
       "  foreach(bar, []) {}\n",
       4, 3);
 }
+
+// Disallow standalone {} for introducing new scopes. These are ambiguous with
+// target declarations (e.g. is:
+//   foo("bar") {}
+// a function with an associated block, or a standalone function with a
+// freestanding block.
+TEST(Parser, StandaloneBlock) {
+  DoParserErrorTest(
+      "if (true) {\n"
+      "}\n"
+      "{\n"
+      "  assert(false)\n"
+      "}\n",
+      3, 1);
+}