llvm-project/lldb/source/Commands/CommandObjectHelp.cpp

//===-- CommandObjectHelp.cpp -----------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "CommandObjectHelp.h"

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Interpreter/CommandObjectMultiword.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Interpreter/Options.h"
#include "lldb/Interpreter/CommandReturnObject.h"

using namespace lldb;
using namespace lldb_private;

//-------------------------------------------------------------------------
// CommandObjectHelp
//-------------------------------------------------------------------------

CommandObjectHelp::CommandObjectHelp () :
    CommandObject ("help",
                     "Shows a list of all debugger commands, or give details about specific commands.",
                     "help [<cmd-name>]")
{
}

CommandObjectHelp::~CommandObjectHelp()
{
}


bool
CommandObjectHelp::OldExecute
(
    Args& command,
    CommandContext *context,
    CommandInterpreter *interpreter,
    CommandReturnObject &result
)
{
    CommandObject::CommandMap::iterator pos;
    CommandObject *cmd_obj;

    const int argc = command.GetArgumentCount();
    if (argc > 0)
    {
        cmd_obj = interpreter->GetCommandObject (command.GetArgumentAtIndex(0), false, false);
        if (cmd_obj == NULL)
        {
            cmd_obj = interpreter->GetCommandObject (command.GetArgumentAtIndex(0), true, false);
            if (cmd_obj != NULL)
            {
                StreamString alias_help_str;
                interpreter->GetAliasHelp (command.GetArgumentAtIndex(0), cmd_obj->GetCommandName(), alias_help_str);
                result.AppendMessageWithFormat ("'%s' is an alias for %s.\n", command.GetArgumentAtIndex (0),
                                               alias_help_str.GetData());
            }
        }

        if (cmd_obj)
        {
            Stream &output_strm = result.GetOutputStream();
            if (cmd_obj->GetOptions() != NULL)
            {
                const char * long_help = cmd_obj->GetHelpLong();
                if ((long_help!= NULL)
                    && strlen (long_help) > 0)
                    output_strm.Printf ("\n%s", cmd_obj->GetHelpLong());
                else
                    output_strm.Printf ("\n%s\n", cmd_obj->GetHelp());
                output_strm.Printf ("\nSyntax: %s\n", cmd_obj->GetSyntax());
                cmd_obj->GetOptions()->GenerateOptionUsage (output_strm, cmd_obj);
            }
            else if (cmd_obj->IsMultiwordObject())
            {
                bool done = false;
                if (argc > 1)
                {
                    CommandObject::CommandMap::iterator pos;
                    std::string sub_command = command.GetArgumentAtIndex(1);
                    pos = ((CommandObjectMultiword *) cmd_obj)->m_subcommand_dict.find(sub_command);
                    if (pos != ((CommandObjectMultiword *) cmd_obj)->m_subcommand_dict.end())
                    {
                        CommandObject *sub_cmd_obj = pos->second.get();
                        if (sub_cmd_obj->GetOptions() != NULL)
                        {
                            output_strm.Printf ("\n%s\n", sub_cmd_obj->GetHelp());
                            output_strm.Printf ("\nSyntax: %s\n", sub_cmd_obj->GetSyntax());
                            sub_cmd_obj->GetOptions()->GenerateOptionUsage (output_strm, sub_cmd_obj);
                            done = true;
                        }
                        else
                        {
                            output_strm.Printf ("\n%s\n", sub_cmd_obj->GetHelp());
                            output_strm.Printf ("\nSyntax: %s\n", sub_cmd_obj->GetSyntax());
                            done = true;
                        }
                    }
                }
                if (!done)
                {
                    output_strm.Printf ("%s\n", cmd_obj->GetHelp());
                    ((CommandObjectMultiword *) cmd_obj)->GenerateHelpText (result, interpreter);
                }
            }
            else
            {
                const char *long_help = cmd_obj->GetHelpLong();
                if ((long_help != NULL)
                    && (strlen (long_help) > 0))
                    output_strm.Printf ("\n%s", cmd_obj->GetHelpLong());
                else
                    output_strm.Printf ("\n%s\n", cmd_obj->GetHelp());
                output_strm.Printf ("\nSyntax: %s\n", cmd_obj->GetSyntax());
            }
            result.SetStatus (eReturnStatusSuccessFinishNoResult);
        }
        else
        {
            result.AppendErrorWithFormat
            ("'%s' is not a known command.\nTry 'help' to see a current list of commands.\n",
             command.GetArgumentAtIndex(0));
            result.SetStatus (eReturnStatusFailed);
        }
    }
    else
    {
        result.SetStatus (eReturnStatusSuccessFinishNoResult);
        interpreter->GetHelp(result);
    }
    return result.Succeeded();
}

bool
CommandObjectHelp::Execute (Args &command, CommandContext *context, CommandInterpreter *interpreter, 
                            CommandReturnObject &result)
{
    CommandObject::CommandMap::iterator pos;
    CommandObject *cmd_obj;
    const int argc = command.GetArgumentCount ();

    // 'help' doesn't take any options or arguments, other than command names.  If argc is 0, we show the user
    // all commands and aliases.  Otherwise every argument must be the name of a command or a sub-command.

    if (argc == 0)
    {
        result.SetStatus (eReturnStatusSuccessFinishNoResult);
        interpreter->GetHelp (result);  // General help, for ALL commands.
    }
    else
    {
        // Get command object for the first command argument. Only search built-in command dictionary.
        cmd_obj = interpreter->GetCommandObject (command.GetArgumentAtIndex (0), false, false);
        if (cmd_obj == NULL)
          {
            // That failed, so now search in the aliases dictionary, too.
            cmd_obj = interpreter->GetCommandObject (command.GetArgumentAtIndex (0), true, false);
          }

        if (cmd_obj != NULL)
        {
            bool all_okay = true;
            CommandObject *sub_cmd_obj = cmd_obj;
            // Loop down through sub_command dictionaries until we find the command object that corresponds
            // to the help command entered.
            for (int i = 1; i < argc && all_okay; ++i)
            {
                std::string sub_command = command.GetArgumentAtIndex(i);
                if (! sub_cmd_obj->IsMultiwordObject ())
                {
                    all_okay = false;
                }
                else
                {
                    pos = ((CommandObjectMultiword *) sub_cmd_obj)->m_subcommand_dict.find (sub_command);
                    if (pos != ((CommandObjectMultiword *) sub_cmd_obj)->m_subcommand_dict.end())
                      sub_cmd_obj = pos->second.get();
                    else
                      all_okay = false;
                }
            }

            if (!all_okay || (sub_cmd_obj == NULL))
            {
                std::string cmd_string;
                command.GetCommandString (cmd_string);
                result.AppendErrorWithFormat
                                      ("'%s' is not a known command.\nTry 'help' to see a current list of commands.\n",
                                       cmd_string.c_str());
                result.SetStatus (eReturnStatusFailed);
            }
            else
            {
                Stream &output_strm = result.GetOutputStream();
                if (sub_cmd_obj->GetOptions() != NULL)
                {
                    output_strm.Printf ("%s\n", sub_cmd_obj->GetHelp());
                    output_strm.Printf ("\nSyntax: %s\n", sub_cmd_obj->GetSyntax());
                    sub_cmd_obj->GetOptions()->GenerateOptionUsage (output_strm, sub_cmd_obj);
                    const char *long_help = sub_cmd_obj->GetHelpLong();
                    if ((long_help != NULL)
                        && (strlen (long_help) > 0))
                      output_strm.Printf ("\n%s", long_help);
                }
                else if (sub_cmd_obj->IsMultiwordObject())
                {
                    output_strm.Printf ("%s\n", sub_cmd_obj->GetHelp());
                    ((CommandObjectMultiword *) sub_cmd_obj)->GenerateHelpText (result, interpreter);
                }
                else
                {
                  const char *long_help = sub_cmd_obj->GetHelpLong();
                  if ((long_help != NULL)
                      && (strlen (long_help) > 0))
                    output_strm.Printf ("%s", long_help);
                  else
                    output_strm.Printf ("%s\n", sub_cmd_obj->GetHelp());
                  output_strm.Printf ("\nSyntax: %s\n", sub_cmd_obj->GetSyntax());
                }
            }
        }
        else
        {
            result.AppendErrorWithFormat 
                                      ("'%s' is not a known command.\nTry 'help' to see a current list of commands.\n",
                                       command.GetArgumentAtIndex(0));
            result.SetStatus (eReturnStatusFailed);
        }
    }

    return result.Succeeded();
}

int
CommandObjectHelp::HandleCompletion
(
    Args &input,
    int &cursor_index,
    int &cursor_char_position,
    int match_start_point,
    int max_return_elements,
    CommandInterpreter *interpreter,
    StringList &matches
)
{
    // Return the completions of the commands in the help system:
    if (cursor_index == 0)
    {
        return interpreter->HandleCompletionMatches(input, cursor_index, cursor_char_position, match_start_point, max_return_elements, matches);
    }
    else
    {
        CommandObject *cmd_obj = interpreter->GetCommandObject (input.GetArgumentAtIndex(0), true, false);
        input.Shift();
        cursor_index--;
        return cmd_obj->HandleCompletion (input, cursor_index, cursor_char_position, match_start_point, max_return_elements, interpreter, matches);
    }
}