gn: handle continued suffix comments

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 565 matching lines @@
     "  BLOCK\n"
     "   BINARY(=)\n"
     "    IDENTIFIER(sources)\n"
     "    LIST\n"
     "     LITERAL(\"a\")\n"
     "     LITERAL(\"b\")\n"
     "      +SUFFIX_COMMENT(\"# Comment\")\n";
   DoParserPrintTest(input, expected);
 }
 
+TEST(Parser, CommentsSuffixMultiple) {
+  const char* input =
+    "executable(\"wee\") {\n"
+    "  sources = [\n"
+    "    \"a\",  # This is a comment,\n"
+    "            # and some more,\n"
+    "            # then the end.\n"

[brettw, 2014/09/23 21:49:09]

What about this code:

sources = [ "a" ]  # This source is awesone
# Add some deps
deps = [ ":fpp" ]

Does your code treat it as a continuation? Maybe we should force the # to align
horizontally for them to be considered the same? Can we get a test case for
this?

[scottmg, 2014/09/23 22:41:01]

Yeah, it does treat it as a continuation. I noticed that happening (and updated
the tokenizer test), but I wasn't entirely sure if it was correct or not.

Same column seems like a reasonable heuristic, changed to enforce that.

Added test to tokenizer to make sure they're correctly characterized. As it
happens they weren't actually aligned in this test! (because of the \"s).

+    "  ]\n"
+    "}\n";
+  const char* expected =
+    "BLOCK\n"
+    " FUNCTION(executable)\n"
+    "  LIST\n"
+    "   LITERAL(\"wee\")\n"
+    "  BLOCK\n"
+    "   BINARY(=)\n"
+    "    IDENTIFIER(sources)\n"
+    "    LIST\n"
+    "     LITERAL(\"a\")\n"
+    "      +SUFFIX_COMMENT(\"# This is a comment,\")\n"
+    "      +SUFFIX_COMMENT(\"# and some more,\")\n"
+    "      +SUFFIX_COMMENT(\"# then the end.\")\n";
+  DoParserPrintTest(input, expected);
+}
+
+
 TEST(Parser, HangingIf) {
   DoParserErrorTest("if", 1, 1);
 }
 
 TEST(Parser, NegatingList) {
   DoParserErrorTest("executable(\"wee\") { sources =- [ \"foo.cc\" ] }", 1, 30);
 }