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/file_template.h"
  12 #include "tools/gn/functions.h"
  13 #include "tools/gn/input_conversion.h"
  14 #include "tools/gn/pattern.h"
  15 #include "tools/gn/setup.h"
  16 #include "tools/gn/standard_out.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-exec: Skips exec_script calls (for performance testing).");
  39   PrintShortHelp(
  40       "-q: Quiet mode, don't print anything on success.");
  41   PrintShortHelp(
  42       "--output: Directory for build output (relative to source root).");
  43   PrintShortHelp(
  44       "--root: Specifies source root (overrides .gn file).");
  45   PrintShortHelp(
  46       "--secondary: Specifies secondary 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   // Functions.
  57   OutputString("\nBuildfile functions (type \"gn help <function>\" for more "
  58                "details):\n");
  59   const functions::FunctionInfoMap& function_map = functions::GetFunctions();
  60   std::vector<std::string> sorted_functions;
  61   for (functions::FunctionInfoMap::const_iterator i = function_map.begin();
  62        i != function_map.end(); ++i)
  63     sorted_functions.push_back(i->first.as_string());
  64   std::sort(sorted_functions.begin(), sorted_functions.end());
  65   for (size_t i = 0; i < sorted_functions.size(); i++)
  66     OutputString("  " + sorted_functions[i] + "\n", DECORATION_YELLOW);
  67
  68   // Built-in variables.
  69   OutputString("\nBuilt-in predefined variables (type \"gn help <variable>\" "
  70                "for more details):\n");
  71   const variables::VariableInfoMap& builtin_vars =
  72       variables::GetBuiltinVariables();
  73   for (variables::VariableInfoMap::const_iterator i = builtin_vars.begin();
  74        i != builtin_vars.end(); ++i)
  75     PrintShortHelp(i->second.help_short);
  76
  77   // Target variables.
  78   OutputString("\nVariables you set in targets (type \"gn help <variable>\" "
  79                "for more details):\n");
  80   const variables::VariableInfoMap& target_vars =
  81       variables::GetTargetVariables();
  82   for (variables::VariableInfoMap::const_iterator i = target_vars.begin();
  83        i != target_vars.end(); ++i)
  84     PrintShortHelp(i->second.help_short);
  85
  86   OutputString("\nOther help topics:\n");
  87   PrintShortHelp("buildargs: How build arguments work.");
  88   PrintShortHelp("dotfile: Info about the toplevel .gn file.");
  89   PrintShortHelp(
  90       "input_conversion: Processing input from exec_script and read_file.");
  91   PrintShortHelp("patterns: How to use patterns.");
  92   PrintShortHelp("source_expansion: Map sources to outputs for scripts.");
  93 }
  94
  95 }  // namespace
  96
  97 const char kHelp[] = "help";
  98 const char kHelp_HelpShort[] =
  99     "help: Does what you think.";
 100 const char kHelp_Help[] =
 101     "gn help <anything>\n"
 102     "  Yo dawg, I heard you like help on your help so I put help on the help\n"
 103     "  in the help.\n";
 104
 105 int RunHelp(const std::vector<std::string>& args) {
 106   if (args.size() == 0) {
 107     PrintToplevelHelp();
 108     return 0;
 109   }
 110
 111   // Check commands.
 112   const commands::CommandInfoMap& command_map = commands::GetCommands();
 113   commands::CommandInfoMap::const_iterator found_command =
 114       command_map.find(args[0]);
 115   if (found_command != command_map.end()) {
 116     PrintLongHelp(found_command->second.help);
 117     return 0;
 118   }
 119
 120   // Check functions.
 121   const functions::FunctionInfoMap& function_map = functions::GetFunctions();
 122   functions::FunctionInfoMap::const_iterator found_function =
 123       function_map.find(args[0]);
 124   if (found_function != function_map.end()) {
 125     PrintLongHelp(found_function->second.help);
 126     return 0;
 127   }
 128
 129   // Builtin variables.
 130   const variables::VariableInfoMap& builtin_vars =
 131       variables::GetBuiltinVariables();
 132   variables::VariableInfoMap::const_iterator found_builtin_var =
 133       builtin_vars.find(args[0]);
 134   if (found_builtin_var != builtin_vars.end()) {
 135     PrintLongHelp(found_builtin_var->second.help);
 136     return 0;
 137   }
 138
 139   // Target variables.
 140   const variables::VariableInfoMap& target_vars =
 141       variables::GetTargetVariables();
 142   variables::VariableInfoMap::const_iterator found_target_var =
 143       target_vars.find(args[0]);
 144   if (found_target_var != target_vars.end()) {
 145     PrintLongHelp(found_target_var->second.help);
 146     return 0;
 147   }
 148
 149   // Random other topics.
 150   if (args[0] == "buildargs") {
 151     PrintLongHelp(kBuildArgs_Help);
 152     return 0;
 153   }
 154   if (args[0] == "dotfile") {
 155     PrintLongHelp(kDotfile_Help);
 156     return 0;
 157   }
 158   if (args[0] == "input_conversion") {
 159     PrintLongHelp(kInputConversion_Help);
 160     return 0;
 161   }
 162   if (args[0] == "patterns") {
 163     PrintLongHelp(kPattern_Help);
 164     return 0;
 165   }
 166   if (args[0] == "source_expansion") {
 167     PrintLongHelp(kSourceExpansion_Help);
 168     return 0;
 169   }
 170
 171   // No help on this.
 172   Err(Location(), "No help on \"" + args[0] + "\".").PrintToStdout();
 173   RunHelp(std::vector<std::string>());
 174   return 1;
 175 }
 176
 177 }  // namespace commands