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