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::Execute (CommandInterpreter &interpreter, Args& command, 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.
        StringList matches;
        cmd_obj = interpreter.GetCommandObject (command.GetArgumentAtIndex (0), &matches);
        
        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 (interpreter, result);
                }
                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 if (matches.GetSize() > 0)
        {
            Stream &output_strm = result.GetOutputStream();
            output_strm.Printf("Help requested with ambiguous command name, possible completions:\n");
            const uint32_t match_count = matches.GetSize();
            for (uint32_t i = 0; i < match_count; i++)
            {
                output_strm.Printf("\t%s\n", matches.GetStringAtIndex(i));
            }
        }
        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
(
    CommandInterpreter &interpreter,
    Args &input,
    int &cursor_index,
    int &cursor_char_position,
    int match_start_point,
    int max_return_elements,
    bool &word_complete,
    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, word_complete, matches);
    }
    else
    {
        CommandObject *cmd_obj = interpreter.GetCommandObject (input.GetArgumentAtIndex(0));
        input.Shift();
        cursor_index--;
        return cmd_obj->HandleCompletion (interpreter, input, cursor_index, cursor_char_position, match_start_point, 
                                          max_return_elements, word_complete, matches);
    }
}