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