Enhance GN diagnostic tools

tools/gn/command_help.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 <algorithm>
 #include <iostream>
 
 #include "tools/gn/args.h"
 #include "tools/gn/commands.h"
 #include "tools/gn/err.h"
 #include "tools/gn/functions.h"
 #include "tools/gn/input_conversion.h"
-#include "tools/gn/pattern.h"
+#include "tools/gn/label_pattern.h"
 #include "tools/gn/setup.h"
 #include "tools/gn/standard_out.h"
 #include "tools/gn/substitution_writer.h"
 #include "tools/gn/variables.h"
 
 namespace commands {
 
 namespace {
 
 void PrintToplevelHelp() {
@@ skipping 62 matching lines @@
                "for more details):\n");
   const variables::VariableInfoMap& target_vars =
       variables::GetTargetVariables();
   for (variables::VariableInfoMap::const_iterator i = target_vars.begin();
        i != target_vars.end(); ++i)
     PrintShortHelp(i->second.help_short);
 
   OutputString("\nOther help topics:\n");
   PrintShortHelp("buildargs: How build arguments work.");
   PrintShortHelp("dotfile: Info about the toplevel .gn file.");
+  PrintShortHelp("label_pattern: Matching more than one label.");
   PrintShortHelp(
       "input_conversion: Processing input from exec_script and read_file.");
-  PrintShortHelp("patterns: How to use patterns.");
   PrintShortHelp("source_expansion: Map sources to outputs for scripts.");
 }
 
 }  // namespace
 
 const char kHelp[] = "help";
 const char kHelp_HelpShort[] =
     "help: Does what you think.";
 const char kHelp_Help[] =
     "gn help <anything>\n"
@@ skipping 50 matching lines @@
     return 0;
   }
   if (args[0] == "dotfile") {
     PrintLongHelp(kDotfile_Help);
     return 0;
   }
   if (args[0] == "input_conversion") {
     PrintLongHelp(kInputConversion_Help);
     return 0;
   }
-  if (args[0] == "patterns") {
-    PrintLongHelp(kPattern_Help);
+  if (args[0] == "label_pattern") {
+    PrintLongHelp(kLabelPattern_Help);
     return 0;
   }
   if (args[0] == "source_expansion") {
     PrintLongHelp(kSourceExpansion_Help);
     return 0;
   }
 
   // No help on this.
   Err(Location(), "No help on \"" + args[0] + "\".").PrintToStdout();
   RunHelp(std::vector<std::string>());
   return 1;
 }
 
 }  // namespace commands