src/tools/gn/command_help.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include <algorithm>
   6 #include <iostream>
   7
   8 #include "tools/gn/args.h"
   9 #include "tools/gn/commands.h"
  10 #include "tools/gn/err.h"
  11 #include "tools/gn/functions.h"
  12 #include "tools/gn/input_conversion.h"
  13 #include "tools/gn/label_pattern.h"
  14 #include "tools/gn/setup.h"
  15 #include "tools/gn/standard_out.h"
  16 #include "tools/gn/substitution_writer.h"
  17 #include "tools/gn/variables.h"
  18
  19 namespace commands {
  20
  21 namespace {
  22
  23 void PrintToplevelHelp() {
  24   OutputString("Commands (type \"gn help <command>\" for more details):\n");
  25
  26   const commands::CommandInfoMap& command_map = commands::GetCommands();
  27   for (commands::CommandInfoMap::const_iterator i = command_map.begin();
  28        i != command_map.end(); ++i)
  29     PrintShortHelp(i->second.help_short);
  30
  31   OutputString(
  32       "\n"
  33       "Common switches:\n");
  34   PrintShortHelp(
  35       "--args: Specifies build arguments overrides. "
  36       "See \"gn help buildargs\".");
  37   PrintShortHelp(
  38       "--[no]color: Forces colored output on or off (rather than autodetect).");
  39   PrintShortHelp(
  40       "--dotfile: Specifies an alternate .gn file. See \"gn help dotfile\".");
  41   PrintShortHelp(
  42       "--no-exec: Skips exec_script calls (for performance testing).");
  43   PrintShortHelp(
  44       "-q: Quiet mode, don't print anything on success.");
  45   PrintShortHelp(
  46       "--root: Specifies source root (overrides .gn file).");
  47   PrintShortHelp(
  48       "--time: Outputs a summary of how long everything took.");
  49   PrintShortHelp(
  50       "--tracelog: Writes a Chrome-compatible trace log to the given file.");
  51   PrintShortHelp(
  52       "-v: Verbose mode, print lots of logging.");
  53   PrintShortHelp(
  54       "--version: Print the GN binary's version and exit.");
  55
  56   // Target declarations.
  57   OutputString("\nTarget declarations (type \"gn help <function>\" for more "
  58                "details):\n");
  59   const functions::FunctionInfoMap& function_map = functions::GetFunctions();
  60   for (functions::FunctionInfoMap::const_iterator i = function_map.begin();
  61        i != function_map.end(); ++i) {
  62     if (i->second.is_target)
  63       PrintShortHelp(i->second.help_short);
  64   }
  65
  66   // Functions.
  67   OutputString("\nBuildfile functions (type \"gn help <function>\" for more "
  68                "details):\n");
  69   for (functions::FunctionInfoMap::const_iterator i = function_map.begin();
  70        i != function_map.end(); ++i) {
  71     if (!i->second.is_target)
  72       PrintShortHelp(i->second.help_short);
  73   }
  74
  75   // Built-in variables.
  76   OutputString("\nBuilt-in predefined variables (type \"gn help <variable>\" "
  77                "for more details):\n");
  78   const variables::VariableInfoMap& builtin_vars =
  79       variables::GetBuiltinVariables();
  80   for (variables::VariableInfoMap::const_iterator i = builtin_vars.begin();
  81        i != builtin_vars.end(); ++i)
  82     PrintShortHelp(i->second.help_short);
  83
  84   // Target variables.
  85   OutputString("\nVariables you set in targets (type \"gn help <variable>\" "
  86                "for more details):\n");
  87   const variables::VariableInfoMap& target_vars =
  88       variables::GetTargetVariables();
  89   for (variables::VariableInfoMap::const_iterator i = target_vars.begin();
  90        i != target_vars.end(); ++i)
  91     PrintShortHelp(i->second.help_short);
  92
  93   OutputString("\nOther help topics:\n");
  94   PrintShortHelp("buildargs: How build arguments work.");
  95   PrintShortHelp("dotfile: Info about the toplevel .gn file.");
  96   PrintShortHelp("label_pattern: Matching more than one label.");
  97   PrintShortHelp(
  98       "input_conversion: Processing input from exec_script and read_file.");
  99   PrintShortHelp("source_expansion: Map sources to outputs for scripts.");
 100 }
 101
 102 }  // namespace
 103
 104 const char kHelp[] = "help";
 105 const char kHelp_HelpShort[] =
 106     "help: Does what you think.";
 107 const char kHelp_Help[] =
 108     "gn help <anything>\n"
 109     "  Yo dawg, I heard you like help on your help so I put help on the help\n"
 110     "  in the help.\n";
 111
 112 int RunHelp(const std::vector<std::string>& args) {
 113   if (args.size() == 0) {
 114     PrintToplevelHelp();
 115     return 0;
 116   }
 117
 118   // Check commands.
 119   const commands::CommandInfoMap& command_map = commands::GetCommands();
 120   commands::CommandInfoMap::const_iterator found_command =
 121       command_map.find(args[0]);
 122   if (found_command != command_map.end()) {
 123     PrintLongHelp(found_command->second.help);
 124     return 0;
 125   }
 126
 127   // Check functions.
 128   const functions::FunctionInfoMap& function_map = functions::GetFunctions();
 129   functions::FunctionInfoMap::const_iterator found_function =
 130       function_map.find(args[0]);
 131   if (found_function != function_map.end()) {
 132     PrintLongHelp(found_function->second.help);
 133     return 0;
 134   }
 135
 136   // Builtin variables.
 137   const variables::VariableInfoMap& builtin_vars =
 138       variables::GetBuiltinVariables();
 139   variables::VariableInfoMap::const_iterator found_builtin_var =
 140       builtin_vars.find(args[0]);
 141   if (found_builtin_var != builtin_vars.end()) {
 142     PrintLongHelp(found_builtin_var->second.help);
 143     return 0;
 144   }
 145
 146   // Target variables.
 147   const variables::VariableInfoMap& target_vars =
 148       variables::GetTargetVariables();
 149   variables::VariableInfoMap::const_iterator found_target_var =
 150       target_vars.find(args[0]);
 151   if (found_target_var != target_vars.end()) {
 152     PrintLongHelp(found_target_var->second.help);
 153     return 0;
 154   }
 155
 156   // Random other topics.
 157   if (args[0] == "buildargs") {
 158     PrintLongHelp(kBuildArgs_Help);
 159     return 0;
 160   }
 161   if (args[0] == "dotfile") {
 162     PrintLongHelp(kDotfile_Help);
 163     return 0;
 164   }
 165   if (args[0] == "input_conversion") {
 166     PrintLongHelp(kInputConversion_Help);
 167     return 0;
 168   }
 169   if (args[0] == "label_pattern") {
 170     PrintLongHelp(kLabelPattern_Help);
 171     return 0;
 172   }
 173   if (args[0] == "source_expansion") {
 174     PrintLongHelp(kSourceExpansion_Help);
 175     return 0;
 176   }
 177
 178   // No help on this.
 179   Err(Location(), "No help on \"" + args[0] + "\".").PrintToStdout();
 180   RunHelp(std::vector<std::string>());
 181   return 1;
 182 }
 183
 184 }  // namespace commands