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 // C Includes
11 // C++ Includes
12 // Other libraries and framework includes
13 // Project includes
14 #include "CommandObjectHelp.h"
15 #include "lldb/Interpreter/CommandObjectMultiword.h"
16 #include "lldb/Interpreter/CommandInterpreter.h"
17 #include "lldb/Interpreter/Options.h"
18 #include "lldb/Interpreter/CommandReturnObject.h"
19 
20 using namespace lldb;
21 using namespace lldb_private;
22 
23 //-------------------------------------------------------------------------
24 // CommandObjectHelp
25 //-------------------------------------------------------------------------
26 
27 void
28 CommandObjectHelp::GenerateAdditionalHelpAvenuesMessage (Stream *s,
29                                                          const char* command,
30                                                          const char* prefix,
31                                                          const char* subcommand,
32                                                          bool include_apropos,
33                                                          bool include_type_lookup)
34 {
35     if (s && command && *command)
36     {
37         s->Printf("'%s' is not a known command.\n", command);
38         if (prefix && *prefix)
39         {
40             s->Printf("Try '%shelp' to see a current list of commands.\n", prefix);
41         }
42         else
43         {
44             s->PutCString("Try 'help' to see a current list of commands.\n");
45         }
46 
47         if (include_apropos)
48         {
49             s->Printf("Try 'apropos %s' for a list of related commands.\n", subcommand ? subcommand : command);
50         }
51         if (include_type_lookup)
52         {
53             s->Printf("Try 'type lookup %s' for information on types, methods, functions, modules, etc.", subcommand ? subcommand : command);
54         }
55     }
56 }
57 
58 CommandObjectHelp::CommandObjectHelp (CommandInterpreter &interpreter) :
59     CommandObjectParsed (interpreter,
60                          "help",
61                          "Show a list of all debugger commands, or give details about specific commands.",
62                          "help [<cmd-name>]"), m_options (interpreter)
63 {
64     CommandArgumentEntry arg;
65     CommandArgumentData command_arg;
66 
67     // Define the first (and only) variant of this arg.
68     command_arg.arg_type = eArgTypeCommandName;
69     command_arg.arg_repetition = eArgRepeatStar;
70 
71     // There is only one variant this argument could be; put it into the argument entry.
72     arg.push_back (command_arg);
73 
74     // Push the data for the first argument into the m_arguments vector.
75     m_arguments.push_back (arg);
76 }
77 
78 CommandObjectHelp::~CommandObjectHelp() = default;
79 
80 OptionDefinition
81 CommandObjectHelp::CommandOptions::g_option_table[] =
82 {
83     { LLDB_OPT_SET_ALL, false, "hide-aliases", 'a', OptionParser::eNoArgument, nullptr, nullptr, 0, eArgTypeNone,         "Hide aliases in the command list."},
84     { LLDB_OPT_SET_ALL, false, "hide-user-commands", 'u', OptionParser::eNoArgument, nullptr, nullptr, 0, eArgTypeNone,         "Hide user-defined commands from the list."},
85     { LLDB_OPT_SET_ALL, false, "show-hidden-commands", 'h', OptionParser::eNoArgument, nullptr, nullptr, 0, eArgTypeNone,         "Include commands prefixed with an underscore."},
86     { 0, false, nullptr, 0, 0, nullptr, nullptr, 0, eArgTypeNone, nullptr }
87 };
88 
89 bool
90 CommandObjectHelp::DoExecute (Args& command, CommandReturnObject &result)
91 {
92     CommandObject::CommandMap::iterator pos;
93     CommandObject *cmd_obj;
94     const size_t argc = command.GetArgumentCount ();
95 
96     // 'help' doesn't take any arguments, other than command names.  If argc is 0, we show the user
97     // all commands (aliases and user commands if asked for).  Otherwise every argument must be the name of a command or a sub-command.
98     if (argc == 0)
99     {
100         uint32_t cmd_types = CommandInterpreter::eCommandTypesBuiltin;
101         if (m_options.m_show_aliases)
102             cmd_types |= CommandInterpreter::eCommandTypesAliases;
103         if (m_options.m_show_user_defined)
104             cmd_types |= CommandInterpreter::eCommandTypesUserDef;
105         if (m_options.m_show_hidden)
106             cmd_types |= CommandInterpreter::eCommandTypesHidden;
107 
108         result.SetStatus (eReturnStatusSuccessFinishNoResult);
109         m_interpreter.GetHelp (result, cmd_types);  // General help
110     }
111     else
112     {
113         // Get command object for the first command argument. Only search built-in command dictionary.
114         StringList matches;
115         cmd_obj = m_interpreter.GetCommandObject (command.GetArgumentAtIndex (0), &matches);
116         bool is_alias_command = m_interpreter.AliasExists (command.GetArgumentAtIndex (0));
117         std::string alias_name = command.GetArgumentAtIndex(0);
118 
119         if (cmd_obj != nullptr)
120         {
121             StringList matches;
122             bool all_okay = true;
123             CommandObject *sub_cmd_obj = cmd_obj;
124             // Loop down through sub_command dictionaries until we find the command object that corresponds
125             // to the help command entered.
126             std::string sub_command;
127             for (size_t i = 1; i < argc && all_okay; ++i)
128             {
129                 sub_command = command.GetArgumentAtIndex(i);
130                 matches.Clear();
131                 if (sub_cmd_obj->IsAlias())
132                     sub_cmd_obj = ((CommandAlias*)sub_cmd_obj)->GetUnderlyingCommand().get();
133                 if (! sub_cmd_obj->IsMultiwordObject ())
134                 {
135                     all_okay = false;
136                 }
137                 else
138                 {
139                     CommandObject *found_cmd;
140                     found_cmd = sub_cmd_obj->GetSubcommandObject(sub_command.c_str(), &matches);
141                     if (found_cmd == nullptr)
142                         all_okay = false;
143                     else if (matches.GetSize() > 1)
144                         all_okay = false;
145                     else
146                         sub_cmd_obj = found_cmd;
147                 }
148             }
149 
150             if (!all_okay || (sub_cmd_obj == nullptr))
151             {
152                 std::string cmd_string;
153                 command.GetCommandString (cmd_string);
154                 if (matches.GetSize() >= 2)
155                 {
156                     StreamString s;
157                     s.Printf ("ambiguous command %s", cmd_string.c_str());
158                     size_t num_matches = matches.GetSize();
159                     for (size_t match_idx = 0; match_idx < num_matches; match_idx++)
160                     {
161                         s.Printf ("\n\t%s", matches.GetStringAtIndex(match_idx));
162                     }
163                     s.Printf ("\n");
164                     result.AppendError(s.GetData());
165                     result.SetStatus (eReturnStatusFailed);
166                     return false;
167                 }
168                 else if (!sub_cmd_obj)
169                 {
170                     StreamString error_msg_stream;
171                     GenerateAdditionalHelpAvenuesMessage(&error_msg_stream,
172                                                          cmd_string.c_str(),
173                                                          m_interpreter.GetCommandPrefix(),
174                                                          sub_command.c_str());
175                     result.AppendErrorWithFormat("%s",error_msg_stream.GetData());
176                     result.SetStatus (eReturnStatusFailed);
177                     return false;
178                 }
179                 else
180                 {
181                     GenerateAdditionalHelpAvenuesMessage(&result.GetOutputStream(),
182                                                          cmd_string.c_str(),
183                                                          m_interpreter.GetCommandPrefix(),
184                                                          sub_command.c_str());
185                     result.GetOutputStream().Printf("\nThe closest match is '%s'. Help on it follows.\n\n", sub_cmd_obj->GetCommandName());
186                 }
187             }
188 
189             sub_cmd_obj->GenerateHelpText(result);
190 
191             if (is_alias_command)
192             {
193                 StreamString sstr;
194                 m_interpreter.GetAlias(alias_name.c_str())->GetAliasExpansion(sstr);
195                 result.GetOutputStream().Printf ("\n'%s' is an abbreviation for %s\n", alias_name.c_str(), sstr.GetData());
196             }
197         }
198         else if (matches.GetSize() > 0)
199         {
200             Stream &output_strm = result.GetOutputStream();
201             output_strm.Printf("Help requested with ambiguous command name, possible completions:\n");
202             const size_t match_count = matches.GetSize();
203             for (size_t i = 0; i < match_count; i++)
204             {
205                 output_strm.Printf("\t%s\n", matches.GetStringAtIndex(i));
206             }
207         }
208         else
209         {
210             // Maybe the user is asking for help about a command argument rather than a command.
211             const CommandArgumentType arg_type = CommandObject::LookupArgumentName (command.GetArgumentAtIndex (0));
212             if (arg_type != eArgTypeLastArg)
213             {
214                 Stream &output_strm = result.GetOutputStream ();
215                 CommandObject::GetArgumentHelp (output_strm, arg_type, m_interpreter);
216                 result.SetStatus (eReturnStatusSuccessFinishNoResult);
217             }
218             else
219             {
220                 StreamString error_msg_stream;
221                 GenerateAdditionalHelpAvenuesMessage(&error_msg_stream, command.GetArgumentAtIndex(0), m_interpreter.GetCommandPrefix());
222                 result.AppendErrorWithFormat("%s",error_msg_stream.GetData());
223                 result.SetStatus (eReturnStatusFailed);
224             }
225         }
226     }
227 
228     return result.Succeeded();
229 }
230 
231 int
232 CommandObjectHelp::HandleCompletion(Args &input,
233                                     int &cursor_index,
234                                     int &cursor_char_position,
235                                     int match_start_point,
236                                     int max_return_elements,
237                                     bool &word_complete,
238                                     StringList &matches)
239 {
240     // Return the completions of the commands in the help system:
241     if (cursor_index == 0)
242     {
243         return m_interpreter.HandleCompletionMatches (input,
244                                                     cursor_index,
245                                                     cursor_char_position,
246                                                     match_start_point,
247                                                     max_return_elements,
248                                                     word_complete,
249                                                     matches);
250     }
251     else
252     {
253         CommandObject *cmd_obj = m_interpreter.GetCommandObject (input.GetArgumentAtIndex(0));
254 
255         // The command that they are getting help on might be ambiguous, in which case we should complete that,
256         // otherwise complete with the command the user is getting help on...
257 
258         if (cmd_obj)
259         {
260             input.Shift();
261             cursor_index--;
262             return cmd_obj->HandleCompletion (input,
263                                               cursor_index,
264                                               cursor_char_position,
265                                               match_start_point,
266                                               max_return_elements,
267                                               word_complete,
268                                               matches);
269         }
270         else
271         {
272             return m_interpreter.HandleCompletionMatches (input,
273                                                         cursor_index,
274                                                         cursor_char_position,
275                                                         match_start_point,
276                                                         max_return_elements,
277                                                         word_complete,
278                                                         matches);
279         }
280     }
281 }
282