lldb/source/Commands/CommandObjectHelp.cpp

   1 //===-- CommandObjectHelp.cpp ---------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "CommandObjectHelp.h"
  10 #include "lldb/Interpreter/CommandInterpreter.h"
  11 #include "lldb/Interpreter/CommandOptionArgumentTable.h"
  12 #include "lldb/Interpreter/CommandReturnObject.h"
  13
  14 using namespace lldb;
  15 using namespace lldb_private;
  16
  17 // CommandObjectHelp
  18
  19 void CommandObjectHelp::GenerateAdditionalHelpAvenuesMessage(
  20     Stream *s, llvm::StringRef command, llvm::StringRef prefix,
  21     llvm::StringRef subcommand, bool include_upropos,
  22     bool include_type_lookup) {
  23   if (!s || command.empty())
  24     return;
  25
  26   std::string command_str = command.str();
  27   std::string prefix_str = prefix.str();
  28   std::string subcommand_str = subcommand.str();
  29   const std::string &lookup_str =
  30       !subcommand_str.empty() ? subcommand_str : command_str;
  31   s->Printf("'%s' is not a known command.\n", command_str.c_str());
  32   s->Printf("Try '%shelp' to see a current list of commands.\n",
  33             prefix.str().c_str());
  34   if (include_upropos) {
  35     s->Printf("Try '%sapropos %s' for a list of related commands.\n",
  36               prefix_str.c_str(), lookup_str.c_str());
  37   }
  38   if (include_type_lookup) {
  39     s->Printf("Try '%stype lookup %s' for information on types, methods, "
  40               "functions, modules, etc.",
  41               prefix_str.c_str(), lookup_str.c_str());
  42   }
  43 }
  44
  45 CommandObjectHelp::CommandObjectHelp(CommandInterpreter &interpreter)
  46     : CommandObjectParsed(interpreter, "help",
  47                           "Show a list of all debugger "
  48                           "commands, or give details "
  49                           "about a specific command.",
  50                           "help [<cmd-name>]") {
  51   CommandArgumentEntry arg;
  52   CommandArgumentData command_arg;
  53
  54   // A list of command names forming a path to the command we want help on.
  55   // No names is allowed - in which case we dump the top-level help.
  56   command_arg.arg_type = eArgTypeCommand;
  57   command_arg.arg_repetition = eArgRepeatStar;
  58
  59   // There is only one variant this argument could be; put it into the argument
  60   // entry.
  61   arg.push_back(command_arg);
  62
  63   // Push the data for the first argument into the m_arguments vector.
  64   m_arguments.push_back(arg);
  65 }
  66
  67 CommandObjectHelp::~CommandObjectHelp() = default;
  68
  69 #define LLDB_OPTIONS_help
  70 #include "CommandOptions.inc"
  71
  72 llvm::ArrayRef<OptionDefinition>
  73 CommandObjectHelp::CommandOptions::GetDefinitions() {
  74   return llvm::ArrayRef(g_help_options);
  75 }
  76
  77 void CommandObjectHelp::DoExecute(Args &command, CommandReturnObject &result) {
  78   CommandObject::CommandMap::iterator pos;
  79   CommandObject *cmd_obj;
  80   const size_t argc = command.GetArgumentCount();
  81
  82   // 'help' doesn't take any arguments, other than command names.  If argc is
  83   // 0, we show the user all commands (aliases and user commands if asked for).
  84   // Otherwise every argument must be the name of a command or a sub-command.
  85   if (argc == 0) {
  86     uint32_t cmd_types = CommandInterpreter::eCommandTypesBuiltin;
  87     if (m_options.m_show_aliases)
  88       cmd_types |= CommandInterpreter::eCommandTypesAliases;
  89     if (m_options.m_show_user_defined) {
  90       cmd_types |= CommandInterpreter::eCommandTypesUserDef;
  91       cmd_types |= CommandInterpreter::eCommandTypesUserMW;
  92     }
  93     if (m_options.m_show_hidden)
  94       cmd_types |= CommandInterpreter::eCommandTypesHidden;
  95
  96     result.SetStatus(eReturnStatusSuccessFinishNoResult);
  97     m_interpreter.GetHelp(result, cmd_types); // General help
  98   } else {
  99     // Get command object for the first command argument. Only search built-in
 100     // command dictionary.
 101     StringList matches;
 102     auto command_name = command[0].ref();
 103     cmd_obj = m_interpreter.GetCommandObject(command_name, &matches);
 104
 105     if (cmd_obj != nullptr) {
 106       StringList matches;
 107       bool all_okay = true;
 108       CommandObject *sub_cmd_obj = cmd_obj;
 109       // Loop down through sub_command dictionaries until we find the command
 110       // object that corresponds to the help command entered.
 111       std::string sub_command;
 112       for (auto &entry : command.entries().drop_front()) {
 113         sub_command = std::string(entry.ref());
 114         matches.Clear();
 115         if (sub_cmd_obj->IsAlias())
 116           sub_cmd_obj =
 117               ((CommandAlias *)sub_cmd_obj)->GetUnderlyingCommand().get();
 118         if (!sub_cmd_obj->IsMultiwordObject()) {
 119           all_okay = false;
 120           break;
 121         } else {
 122           CommandObject *found_cmd;
 123           found_cmd =
 124               sub_cmd_obj->GetSubcommandObject(sub_command.c_str(), &matches);
 125           if (found_cmd == nullptr || matches.GetSize() > 1) {
 126             all_okay = false;
 127             break;
 128           } else
 129             sub_cmd_obj = found_cmd;
 130         }
 131       }
 132
 133       if (!all_okay || (sub_cmd_obj == nullptr)) {
 134         std::string cmd_string;
 135         command.GetCommandString(cmd_string);
 136         if (matches.GetSize() >= 2) {
 137           StreamString s;
 138           s.Printf("ambiguous command %s", cmd_string.c_str());
 139           size_t num_matches = matches.GetSize();
 140           for (size_t match_idx = 0; match_idx < num_matches; match_idx++) {
 141             s.Printf("\n\t%s", matches.GetStringAtIndex(match_idx));
 142           }
 143           s.Printf("\n");
 144           result.AppendError(s.GetString());
 145           return;
 146         } else if (!sub_cmd_obj) {
 147           StreamString error_msg_stream;
 148           GenerateAdditionalHelpAvenuesMessage(
 149               &error_msg_stream, cmd_string.c_str(),
 150               m_interpreter.GetCommandPrefix(), sub_command.c_str());
 151           result.AppendError(error_msg_stream.GetString());
 152           return;
 153         } else {
 154           GenerateAdditionalHelpAvenuesMessage(
 155               &result.GetOutputStream(), cmd_string.c_str(),
 156               m_interpreter.GetCommandPrefix(), sub_command.c_str());
 157           result.GetOutputStream().Printf(
 158               "\nThe closest match is '%s'. Help on it follows.\n\n",
 159               sub_cmd_obj->GetCommandName().str().c_str());
 160         }
 161       }
 162
 163       sub_cmd_obj->GenerateHelpText(result);
 164       std::string alias_full_name;
 165       // Don't use AliasExists here, that only checks exact name matches.  If
 166       // the user typed a shorter unique alias name, we should still tell them
 167       // it was an alias.
 168       if (m_interpreter.GetAliasFullName(command_name, alias_full_name)) {
 169         StreamString sstr;
 170         m_interpreter.GetAlias(alias_full_name)->GetAliasExpansion(sstr);
 171         result.GetOutputStream().Printf("\n'%s' is an abbreviation for %s\n",
 172                                         command[0].c_str(), sstr.GetData());
 173       }
 174     } else if (matches.GetSize() > 0) {
 175       Stream &output_strm = result.GetOutputStream();
 176       output_strm.Printf("Help requested with ambiguous command name, possible "
 177                          "completions:\n");
 178       const size_t match_count = matches.GetSize();
 179       for (size_t i = 0; i < match_count; i++) {
 180         output_strm.Printf("\t%s\n", matches.GetStringAtIndex(i));
 181       }
 182     } else {
 183       // Maybe the user is asking for help about a command argument rather than
 184       // a command.
 185       const CommandArgumentType arg_type =
 186           CommandObject::LookupArgumentName(command_name);
 187       if (arg_type != eArgTypeLastArg) {
 188         Stream &output_strm = result.GetOutputStream();
 189         CommandObject::GetArgumentHelp(output_strm, arg_type, m_interpreter);
 190         result.SetStatus(eReturnStatusSuccessFinishNoResult);
 191       } else {
 192         StreamString error_msg_stream;
 193         GenerateAdditionalHelpAvenuesMessage(&error_msg_stream, command_name,
 194                                              m_interpreter.GetCommandPrefix(),
 195                                              "");
 196         result.AppendError(error_msg_stream.GetString());
 197       }
 198     }
 199   }
 200 }
 201
 202 void CommandObjectHelp::HandleCompletion(CompletionRequest &request) {
 203   // Return the completions of the commands in the help system:
 204   if (request.GetCursorIndex() == 0) {
 205     m_interpreter.HandleCompletionMatches(request);
 206     return;
 207   }
 208   CommandObject *cmd_obj =
 209       m_interpreter.GetCommandObject(request.GetParsedLine()[0].ref());
 210
 211   // The command that they are getting help on might be ambiguous, in which
 212   // case we should complete that, otherwise complete with the command the
 213   // user is getting help on...
 214
 215   if (cmd_obj) {
 216     request.ShiftArguments();
 217     cmd_obj->HandleCompletion(request);
 218     return;
 219   }
 220   m_interpreter.HandleCompletionMatches(request);
 221 }