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/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       "  When run with no arguments \"gn gen\" is assumed.\n"
  34       "\n"
  35       "Common switches:\n");
  36   PrintShortHelp(
  37       "--args: Specifies build args overrides. See \"gn help buildargs\".");
  38   PrintShortHelp(
  39       "--no-exec: Skips exec_script calls (for performance testing).");
  40   PrintShortHelp(
  41       "-q: Quiet mode, don't print anything on success.");
  42   PrintShortHelp(
  43       "--output: Directory for build output (relative to source root).");
  44   PrintShortHelp(
  45       "--root: Specifies source root (overrides .gn file).");
  46   PrintShortHelp(
  47       "--secondary: Specifies secondary source root (overrides .gn file).");
  48   PrintShortHelp(
  49       "--time: Outputs a summary of how long everything took.");
  50   PrintShortHelp(
  51       "--tracelog: Writes a Chrome-compatible trace log to the given file.");
  52   PrintShortHelp(
  53       "-v: Verbose mode, print lots of logging.");
  54
  55   // Functions.
  56   OutputString("\nBuildfile functions (type \"gn help <function>\" for more "
  57                "details):\n");
  58   const functions::FunctionInfoMap& function_map = functions::GetFunctions();
  59   std::vector<std::string> sorted_functions;
  60   for (functions::FunctionInfoMap::const_iterator i = function_map.begin();
  61        i != function_map.end(); ++i)
  62     sorted_functions.push_back(i->first.as_string());
  63   std::sort(sorted_functions.begin(), sorted_functions.end());
  64   for (size_t i = 0; i < sorted_functions.size(); i++)
  65     OutputString("  " + sorted_functions[i] + "\n", DECORATION_YELLOW);
  66
  67   // Built-in variables.
  68   OutputString("\nBuilt-in predefined variables (type \"gn help <variable>\" "
  69                "for more details):\n");
  70   const variables::VariableInfoMap& builtin_vars =
  71       variables::GetBuiltinVariables();
  72   for (variables::VariableInfoMap::const_iterator i = builtin_vars.begin();
  73        i != builtin_vars.end(); ++i)
  74     PrintShortHelp(i->second.help_short);
  75
  76   // Target variables.
  77   OutputString("\nVariables you set in targets (type \"gn help <variable>\" "
  78                "for more details):\n");
  79   const variables::VariableInfoMap& target_vars =
  80       variables::GetTargetVariables();
  81   for (variables::VariableInfoMap::const_iterator i = target_vars.begin();
  82        i != target_vars.end(); ++i)
  83     PrintShortHelp(i->second.help_short);
  84
  85   OutputString("\nOther help topics:\n");
  86   PrintShortHelp("buildargs: How build arguments work.");
  87   PrintShortHelp("dotfile: Info about the toplevel .gn file.");
  88   PrintShortHelp(
  89       "input_conversion: Processing input from exec_script and read_file.");
  90   PrintShortHelp("patterns: How to use patterns.");
  91   PrintShortHelp("source_expansion: Map sources to outputs for scripts.");
  92 }
  93
  94 }  // namespace
  95
  96 const char kHelp[] = "help";
  97 const char kHelp_HelpShort[] =
  98     "help: Does what you think.";
  99 const char kHelp_Help[] =
 100     "gn help <anything>\n"
 101     "  Yo dawg, I heard you like help on your help so I put help on the help\n"
 102     "  in the help.\n";
 103
 104 int RunHelp(const std::vector<std::string>& args) {
 105   if (args.size() == 0) {
 106     PrintToplevelHelp();
 107     return 0;
 108   }
 109
 110   // Check commands.
 111   const commands::CommandInfoMap& command_map = commands::GetCommands();
 112   commands::CommandInfoMap::const_iterator found_command =
 113       command_map.find(args[0]);
 114   if (found_command != command_map.end()) {
 115     PrintLongHelp(found_command->second.help);
 116     return 0;
 117   }
 118
 119   // Check functions.
 120   const functions::FunctionInfoMap& function_map = functions::GetFunctions();
 121   functions::FunctionInfoMap::const_iterator found_function =
 122       function_map.find(args[0]);
 123   if (found_function != function_map.end()) {
 124     PrintLongHelp(found_function->second.help);
 125     return 0;
 126   }
 127
 128   // Builtin variables.
 129   const variables::VariableInfoMap& builtin_vars =
 130       variables::GetBuiltinVariables();
 131   variables::VariableInfoMap::const_iterator found_builtin_var =
 132       builtin_vars.find(args[0]);
 133   if (found_builtin_var != builtin_vars.end()) {
 134     PrintLongHelp(found_builtin_var->second.help);
 135     return 0;
 136   }
 137
 138   // Target variables.
 139   const variables::VariableInfoMap& target_vars =
 140       variables::GetTargetVariables();
 141   variables::VariableInfoMap::const_iterator found_target_var =
 142       target_vars.find(args[0]);
 143   if (found_target_var != target_vars.end()) {
 144     PrintLongHelp(found_target_var->second.help);
 145     return 0;
 146   }
 147
 148   // Random other topics.
 149   if (args[0] == "buildargs") {
 150     PrintLongHelp(kBuildArgs_Help);
 151     return 0;
 152   }
 153   if (args[0] == "dotfile") {
 154     PrintLongHelp(kDotfile_Help);
 155     return 0;
 156   }
 157   if (args[0] == "input_conversion") {
 158     PrintLongHelp(kInputConversion_Help);
 159     return 0;
 160   }
 161   if (args[0] == "patterns") {
 162     PrintLongHelp(kPattern_Help);
 163     return 0;
 164   }
 165   if (args[0] == "source_expansion") {
 166     PrintLongHelp(kSourceExpansion_Help);
 167     return 0;
 168   }
 169
 170   // No help on this.
 171   Err(Location(), "No help on \"" + args[0] + "\".").PrintToStdout();
 172   RunHelp(std::vector<std::string>());
 173   return 1;
 174 }
 175
 176 }  // namespace commands