Support explicit pools in actions

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 "base/command_line.h"
 #include "tools/gn/args.h"
 #include "tools/gn/commands.h"
@@ skipping 227 matching lines @@
   if (found_command != command_map.end()) {
     PrintLongHelp(found_command->second.help);
     return 0;
   }
   for (const auto& entry : command_map)
     all_help_topics.push_back(entry.first);
 
   // Check functions.
   const functions::FunctionInfoMap& function_map = functions::GetFunctions();
   auto found_function = function_map.find(what);
-  if (found_function != function_map.end()) {
+  if (found_function != function_map.end())
     PrintLongHelp(found_function->second.help);
-    return 0;
-  }
   for (const auto& entry : function_map)
     all_help_topics.push_back(entry.first);
 
   // Builtin variables.
   const variables::VariableInfoMap& builtin_vars =
       variables::GetBuiltinVariables();
   auto found_builtin_var = builtin_vars.find(what);
-  if (found_builtin_var != builtin_vars.end()) {
+  if (found_builtin_var != builtin_vars.end())
     PrintLongHelp(found_builtin_var->second.help);
-    return 0;
-  }
   for (const auto& entry : builtin_vars)
     all_help_topics.push_back(entry.first);
 
   // Target variables.
   const variables::VariableInfoMap& target_vars =
       variables::GetTargetVariables();
   auto found_target_var = target_vars.find(what);
-  if (found_target_var != target_vars.end()) {
+  if (found_target_var != target_vars.end())
     PrintLongHelp(found_target_var->second.help);
-    return 0;
-  }
   for (const auto& entry : target_vars)
     all_help_topics.push_back(entry.first);
 
+  if (found_function != function_map.end() ||
+      found_builtin_var != builtin_vars.end() ||
+      found_target_var != target_vars.end())
+    return 0;
+
   // Random other topics.
   std::map<std::string, void(*)()> random_topics;
   random_topics["all"] = PrintAllHelp;
   random_topics["execution"] = []() { PrintLongHelp(kExecution_Help); };
   random_topics["buildargs"] = []() { PrintLongHelp(kBuildArgs_Help); };
   random_topics["dotfile"] = []() { PrintLongHelp(kDotfile_Help); };
   random_topics["grammar"] = []() { PrintLongHelp(kGrammar_Help); };
   random_topics["input_conversion"] = []() {
     PrintLongHelp(kInputConversion_Help);
   };
@@ skipping 21 matching lines @@
     OutputString("Run `gn help` for a list of available topics.\n",
                  DECORATION_NONE);
   } else {
     OutputString("Did you mean `gn help " + suggestion.as_string() + "`?\n",
                  DECORATION_NONE);
   }
   return 1;
 }
 
 }  // namespace commands