Enhance GN diagnostic tools

tools/gn/pattern.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 "tools/gn/pattern.h"
 
 #include "tools/gn/value.h"
 
-const char kPattern_Help[] =
-    "Patterns\n"
-    "  Patterns are VERY limited regular expressions that are used in\n"
-    "  several places.\n"
-    "\n"
-    "  Patterns must match the entire input string to be counted as a match.\n"
-    "  In regular expression parlance, there is an implicit \"^...$\"\n"
-    "  surrounding your input. If you want to match a substring, you need to\n"
-    "  use wildcards at the beginning and end.\n"
-    "\n"
-    "  There are only two special tokens understood by the pattern matcher.\n"
-    "  Everything else is a literal.\n"
-    "\n"
-    "   * Matches zero or more of any character. It does not depend on the\n"
-    "     preceding character (in regular expression parlance it is\n"
-    "     equivalent to \".*\").\n"
-    "\n"
-    "  \\b Matches a path boundary. This will match the beginning or end of\n"
-    "     a string, or a slash.\n"
-    "\n"
-    "Examples\n"
-    "\n"
-    "  \"*asdf*\"\n"
-    "      Matches a string containing \"asdf\" anywhere.\n"
-    "\n"
-    "  \"asdf\"\n"
-    "      Matches only the exact string \"asdf\".\n"
-    "\n"
-    "  \"*.cc\"\n"
-    "      Matches strings ending in the literal \".cc\".\n"
-    "\n"
-    "  \"\\bwin/*\"\n"
-    "      Matches \"win/foo\" and \"foo/win/bar.cc\" but not \"iwin/foo\".\n";
-
 namespace {
 
 void ParsePattern(const std::string& s, std::vector<Pattern::Subrange>* out) {
   // Set when the last subrange is a literal so we can just append when we
   // find another literal.
   Pattern::Subrange* last_literal = NULL;
 
   for (size_t i = 0; i < s.size(); i++) {
     if (s[i] == '*') {
       // Don't allow two **.
@@ skipping 161 matching lines @@
       return true;
   }
   return false;
 }
 
 bool PatternList::MatchesValue(const Value& v) const {
   if (v.type() == Value::STRING)
     return MatchesString(v.string_value());
   return false;
 }