xref: /llvm-project/lldb/source/Commands/CommandObjectHelp.cpp (revision ceff6644bba4d6c5e9c338afe92c453c7597609b)
1 //===-- CommandObjectHelp.cpp -----------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "CommandObjectHelp.h"
11 #include "lldb/Interpreter/CommandInterpreter.h"
12 #include "lldb/Interpreter/CommandObjectMultiword.h"
13 #include "lldb/Interpreter/CommandReturnObject.h"
14 #include "lldb/Interpreter/Options.h"
15 
16 using namespace lldb;
17 using namespace lldb_private;
18 
19 //-------------------------------------------------------------------------
20 // CommandObjectHelp
21 //-------------------------------------------------------------------------
22 
23 void CommandObjectHelp::GenerateAdditionalHelpAvenuesMessage(
24     Stream *s, llvm::StringRef command, llvm::StringRef prefix, llvm::StringRef subcommand,
25     bool include_apropos, bool include_type_lookup) {
26   if (!s || command.empty())
27     return;
28 
29   std::string command_str = command.str();
30   std::string prefix_str = prefix.str();
31   std::string subcommand_str = subcommand.str();
32   const std::string &lookup_str = !subcommand_str.empty() ? subcommand_str : command_str;
33   s->Printf("'%s' is not a known command.\n", command_str.c_str());
34   s->Printf("Try '%shelp' to see a current list of commands.\n",
35             prefix.str().c_str());
36   if (include_apropos) {
37     s->Printf("Try '%sapropos %s' for a list of related commands.\n",
38       prefix_str.c_str(), lookup_str.c_str());
39   }
40   if (include_type_lookup) {
41     s->Printf("Try '%stype lookup %s' for information on types, methods, "
42               "functions, modules, etc.",
43       prefix_str.c_str(), lookup_str.c_str());
44   }
45 }
46 
47 CommandObjectHelp::CommandObjectHelp(CommandInterpreter &interpreter)
48     : CommandObjectParsed(interpreter, "help", "Show a list of all debugger "
49                                                "commands, or give details "
50                                                "about a specific command.",
51                           "help [<cmd-name>]"),
52       m_options() {
53   CommandArgumentEntry arg;
54   CommandArgumentData command_arg;
55 
56   // Define the first (and only) variant of this arg.
57   command_arg.arg_type = eArgTypeCommandName;
58   command_arg.arg_repetition = eArgRepeatStar;
59 
60   // There is only one variant this argument could be; put it into the argument
61   // entry.
62   arg.push_back(command_arg);
63 
64   // Push the data for the first argument into the m_arguments vector.
65   m_arguments.push_back(arg);
66 }
67 
68 CommandObjectHelp::~CommandObjectHelp() = default;
69 
70 static constexpr OptionDefinition g_help_options[] = {
71     // clang-format off
72   {LLDB_OPT_SET_ALL, false, "hide-aliases",         'a', OptionParser::eNoArgument, nullptr, {}, 0, eArgTypeNone, "Hide aliases in the command list."},
73   {LLDB_OPT_SET_ALL, false, "hide-user-commands",   'u', OptionParser::eNoArgument, nullptr, {}, 0, eArgTypeNone, "Hide user-defined commands from the list."},
74   {LLDB_OPT_SET_ALL, false, "show-hidden-commands", 'h', OptionParser::eNoArgument, nullptr, {}, 0, eArgTypeNone, "Include commands prefixed with an underscore."},
75     // clang-format on
76 };
77 
78 llvm::ArrayRef<OptionDefinition>
79 CommandObjectHelp::CommandOptions::GetDefinitions() {
80   return llvm::makeArrayRef(g_help_options);
81 }
82 
83 bool CommandObjectHelp::DoExecute(Args &command, CommandReturnObject &result) {
84   CommandObject::CommandMap::iterator pos;
85   CommandObject *cmd_obj;
86   const size_t argc = command.GetArgumentCount();
87 
88   // 'help' doesn't take any arguments, other than command names.  If argc is
89   // 0, we show the user all commands (aliases and user commands if asked for).
90   // Otherwise every argument must be the name of a command or a sub-command.
91   if (argc == 0) {
92     uint32_t cmd_types = CommandInterpreter::eCommandTypesBuiltin;
93     if (m_options.m_show_aliases)
94       cmd_types |= CommandInterpreter::eCommandTypesAliases;
95     if (m_options.m_show_user_defined)
96       cmd_types |= CommandInterpreter::eCommandTypesUserDef;
97     if (m_options.m_show_hidden)
98       cmd_types |= CommandInterpreter::eCommandTypesHidden;
99 
100     result.SetStatus(eReturnStatusSuccessFinishNoResult);
101     m_interpreter.GetHelp(result, cmd_types); // General help
102   } else {
103     // Get command object for the first command argument. Only search built-in
104     // command dictionary.
105     StringList matches;
106     auto command_name = command[0].ref;
107     cmd_obj = m_interpreter.GetCommandObject(command_name, &matches);
108 
109     if (cmd_obj != nullptr) {
110       StringList matches;
111       bool all_okay = true;
112       CommandObject *sub_cmd_obj = cmd_obj;
113       // Loop down through sub_command dictionaries until we find the command
114       // object that corresponds to the help command entered.
115       std::string sub_command;
116       for (auto &entry : command.entries().drop_front()) {
117         sub_command = entry.ref;
118         matches.Clear();
119         if (sub_cmd_obj->IsAlias())
120           sub_cmd_obj =
121               ((CommandAlias *)sub_cmd_obj)->GetUnderlyingCommand().get();
122         if (!sub_cmd_obj->IsMultiwordObject()) {
123           all_okay = false;
124           break;
125         } else {
126           CommandObject *found_cmd;
127           found_cmd =
128               sub_cmd_obj->GetSubcommandObject(sub_command.c_str(), &matches);
129           if (found_cmd == nullptr || matches.GetSize() > 1) {
130             all_okay = false;
131             break;
132           } else
133             sub_cmd_obj = found_cmd;
134         }
135       }
136 
137       if (!all_okay || (sub_cmd_obj == nullptr)) {
138         std::string cmd_string;
139         command.GetCommandString(cmd_string);
140         if (matches.GetSize() >= 2) {
141           StreamString s;
142           s.Printf("ambiguous command %s", cmd_string.c_str());
143           size_t num_matches = matches.GetSize();
144           for (size_t match_idx = 0; match_idx < num_matches; match_idx++) {
145             s.Printf("\n\t%s", matches.GetStringAtIndex(match_idx));
146           }
147           s.Printf("\n");
148           result.AppendError(s.GetString());
149           result.SetStatus(eReturnStatusFailed);
150           return false;
151         } else if (!sub_cmd_obj) {
152           StreamString error_msg_stream;
153           GenerateAdditionalHelpAvenuesMessage(
154               &error_msg_stream, cmd_string.c_str(),
155               m_interpreter.GetCommandPrefix(), sub_command.c_str());
156           result.AppendError(error_msg_stream.GetString());
157           result.SetStatus(eReturnStatusFailed);
158           return false;
159         } else {
160           GenerateAdditionalHelpAvenuesMessage(
161               &result.GetOutputStream(), cmd_string.c_str(),
162               m_interpreter.GetCommandPrefix(), sub_command.c_str());
163           result.GetOutputStream().Printf(
164               "\nThe closest match is '%s'. Help on it follows.\n\n",
165               sub_cmd_obj->GetCommandName().str().c_str());
166         }
167       }
168 
169       sub_cmd_obj->GenerateHelpText(result);
170 
171       if (m_interpreter.AliasExists(command_name)) {
172         StreamString sstr;
173         m_interpreter.GetAlias(command_name)->GetAliasExpansion(sstr);
174         result.GetOutputStream().Printf("\n'%s' is an abbreviation for %s\n",
175                                         command[0].c_str(), sstr.GetData());
176       }
177     } else if (matches.GetSize() > 0) {
178       Stream &output_strm = result.GetOutputStream();
179       output_strm.Printf("Help requested with ambiguous command name, possible "
180                          "completions:\n");
181       const size_t match_count = matches.GetSize();
182       for (size_t i = 0; i < match_count; i++) {
183         output_strm.Printf("\t%s\n", matches.GetStringAtIndex(i));
184       }
185     } else {
186       // Maybe the user is asking for help about a command argument rather than
187       // a command.
188       const CommandArgumentType arg_type =
189           CommandObject::LookupArgumentName(command_name);
190       if (arg_type != eArgTypeLastArg) {
191         Stream &output_strm = result.GetOutputStream();
192         CommandObject::GetArgumentHelp(output_strm, arg_type, m_interpreter);
193         result.SetStatus(eReturnStatusSuccessFinishNoResult);
194       } else {
195         StreamString error_msg_stream;
196         GenerateAdditionalHelpAvenuesMessage(&error_msg_stream, command_name,
197                                              m_interpreter.GetCommandPrefix(),
198                                              "");
199         result.AppendError(error_msg_stream.GetString());
200         result.SetStatus(eReturnStatusFailed);
201       }
202     }
203   }
204 
205   return result.Succeeded();
206 }
207 
208 int CommandObjectHelp::HandleCompletion(CompletionRequest &request) {
209   // Return the completions of the commands in the help system:
210   if (request.GetCursorIndex() == 0) {
211     return m_interpreter.HandleCompletionMatches(request);
212   } else {
213     CommandObject *cmd_obj =
214         m_interpreter.GetCommandObject(request.GetParsedLine()[0].ref);
215 
216     // The command that they are getting help on might be ambiguous, in which
217     // case we should complete that, otherwise complete with the command the
218     // user is getting help on...
219 
220     if (cmd_obj) {
221       request.GetParsedLine().Shift();
222       request.SetCursorIndex(request.GetCursorIndex() - 1);
223       return cmd_obj->HandleCompletion(request);
224     } else {
225       return m_interpreter.HandleCompletionMatches(request);
226     }
227   }
228 }
229