lldb/source/Commands/CommandObjectCommands.cpp

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

#include "lldb/lldb-python.h"

#include "CommandObjectCommands.h"

// C Includes
// C++ Includes
// Other libraries and framework includes
#include "llvm/ADT/StringRef.h"

// Project includes
#include "lldb/Core/Debugger.h"
#include "lldb/Core/IOHandler.h"
#include "lldb/Core/StringList.h"
#include "lldb/Interpreter/Args.h"
#include "lldb/Interpreter/CommandHistory.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Interpreter/CommandObjectRegexCommand.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Interpreter/OptionValueBoolean.h"
#include "lldb/Interpreter/OptionValueUInt64.h"
#include "lldb/Interpreter/Options.h"
#include "lldb/Interpreter/ScriptInterpreter.h"
#include "lldb/Interpreter/ScriptInterpreterPython.h"

using namespace lldb;
using namespace lldb_private;

//-------------------------------------------------------------------------
// CommandObjectCommandsSource
//-------------------------------------------------------------------------

class CommandObjectCommandsHistory : public CommandObjectParsed
{
public:
    CommandObjectCommandsHistory(CommandInterpreter &interpreter) :
        CommandObjectParsed (interpreter,
                             "command history",
                             "Dump the history of commands in this session.",
                             NULL),
        m_options (interpreter)
    {
    }

    ~CommandObjectCommandsHistory () {}

    virtual Options *
    GetOptions ()
    {
        return &m_options;
    }

protected:

    class CommandOptions : public Options
    {
    public:

        CommandOptions (CommandInterpreter &interpreter) :
            Options (interpreter),
            m_start_idx(0),
            m_stop_idx(0),
            m_count(0),
            m_clear(false)
        {
        }

        virtual
        ~CommandOptions (){}

        virtual Error
        SetOptionValue (uint32_t option_idx, const char *option_arg)
        {
            Error error;
            const int short_option = m_getopt_table[option_idx].val;
            
            switch (short_option)
            {
                case 'c':
                    error = m_count.SetValueFromString(option_arg,eVarSetOperationAssign);
                    break;
                case 's':
                    if (option_arg && strcmp("end", option_arg) == 0)
                    {
                        m_start_idx.SetCurrentValue(UINT64_MAX);
                        m_start_idx.SetOptionWasSet();
                    }
                    else
                        error = m_start_idx.SetValueFromString(option_arg,eVarSetOperationAssign);
                    break;
                case 'e':
                    error = m_stop_idx.SetValueFromString(option_arg,eVarSetOperationAssign);
                    break;
                case 'C':
                    m_clear.SetCurrentValue(true);
                    m_clear.SetOptionWasSet();
                    break;
                default:
                    error.SetErrorStringWithFormat ("unrecognized option '%c'", short_option);
                    break;
            }
            
            return error;
        }

        void
        OptionParsingStarting ()
        {
            m_start_idx.Clear();
            m_stop_idx.Clear();
            m_count.Clear();
            m_clear.Clear();
        }

        const OptionDefinition*
        GetDefinitions ()
        {
            return g_option_table;
        }

        // Options table: Required for subclasses of Options.

        static OptionDefinition g_option_table[];

        // Instance variables to hold the values for command options.

        OptionValueUInt64 m_start_idx;
        OptionValueUInt64 m_stop_idx;
        OptionValueUInt64 m_count;
        OptionValueBoolean m_clear;
    };
    
    bool
    DoExecute (Args& command, CommandReturnObject &result)
    {
        if (m_options.m_clear.GetCurrentValue() && m_options.m_clear.OptionWasSet())
        {
            m_interpreter.GetCommandHistory().Clear();
            result.SetStatus(lldb::eReturnStatusSuccessFinishNoResult);
        }
        else
        {
            if (m_options.m_start_idx.OptionWasSet() && m_options.m_stop_idx.OptionWasSet() && m_options.m_count.OptionWasSet())
            {
                result.AppendError("--count, --start-index and --end-index cannot be all specified in the same invocation");
                result.SetStatus(lldb::eReturnStatusFailed);
            }
            else
            {
                std::pair<bool,uint64_t> start_idx(m_options.m_start_idx.OptionWasSet(),m_options.m_start_idx.GetCurrentValue());
                std::pair<bool,uint64_t> stop_idx(m_options.m_stop_idx.OptionWasSet(),m_options.m_stop_idx.GetCurrentValue());
                std::pair<bool,uint64_t> count(m_options.m_count.OptionWasSet(),m_options.m_count.GetCurrentValue());
                
                const CommandHistory& history(m_interpreter.GetCommandHistory());
                                              
                if (start_idx.first && start_idx.second == UINT64_MAX)
                {
                    if (count.first)
                    {
                        start_idx.second = history.GetSize() - count.second;
                        stop_idx.second = history.GetSize() - 1;
                    }
                    else if (stop_idx.first)
                    {
                        start_idx.second = stop_idx.second;
                        stop_idx.second = history.GetSize() - 1;
                    }
                    else
                    {
                        start_idx.second = 0;
                        stop_idx.second = history.GetSize() - 1;
                    }
                }
                else
                {
                    if (!start_idx.first && !stop_idx.first && !count.first)
                    {
                        start_idx.second = 0;
                        stop_idx.second = history.GetSize() - 1;
                    }
                    else if (start_idx.first)
                    {
                        if (count.first)
                        {
                            stop_idx.second = start_idx.second + count.second - 1;
                        }
                        else if (!stop_idx.first)
                        {
                            stop_idx.second = history.GetSize() - 1;
                        }
                    }
                    else if (stop_idx.first)
                    {
                        if (count.first)
                        {
                            if (stop_idx.second >= count.second)
                                start_idx.second = stop_idx.second - count.second + 1;
                            else
                                start_idx.second = 0;
                        }
                    }
                    else /* if (count.first) */
                    {
                        start_idx.second = 0;
                        stop_idx.second = count.second - 1;
                    }
                }
                history.Dump(result.GetOutputStream(), start_idx.second, stop_idx.second);
            }
        }
        return result.Succeeded();

    }

    CommandOptions m_options;
};

OptionDefinition
CommandObjectCommandsHistory::CommandOptions::g_option_table[] =
{
{ LLDB_OPT_SET_1, false, "count", 'c', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeUnsignedInteger,        "How many history commands to print."},
{ LLDB_OPT_SET_1, false, "start-index", 's', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeUnsignedInteger,  "Index at which to start printing history commands (or end to mean tail mode)."},
{ LLDB_OPT_SET_1, false, "end-index", 'e', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeUnsignedInteger,    "Index at which to stop printing history commands."},
{ LLDB_OPT_SET_2, false, "clear", 'C', OptionParser::eNoArgument, NULL, NULL, 0, eArgTypeBoolean,    "Clears the current command history."},
{ 0, false, NULL, 0, 0, NULL, NULL, 0, eArgTypeNone, NULL }
};


//-------------------------------------------------------------------------
// CommandObjectCommandsSource
//-------------------------------------------------------------------------

class CommandObjectCommandsSource : public CommandObjectParsed
{
public:
    CommandObjectCommandsSource(CommandInterpreter &interpreter) :
        CommandObjectParsed (interpreter,
                             "command source",
                             "Read in debugger commands from the file <filename> and execute them.",
                             NULL),
        m_options (interpreter)
    {
        CommandArgumentEntry arg;
        CommandArgumentData file_arg;
        
        // Define the first (and only) variant of this arg.
        file_arg.arg_type = eArgTypeFilename;
        file_arg.arg_repetition = eArgRepeatPlain;
        
        // There is only one variant this argument could be; put it into the argument entry.
        arg.push_back (file_arg);
        
        // Push the data for the first argument into the m_arguments vector.
        m_arguments.push_back (arg);
    }

    ~CommandObjectCommandsSource () {}

    virtual const char*
    GetRepeatCommand (Args &current_command_args, uint32_t index)
    {
        return "";
    }
    
    virtual int
    HandleArgumentCompletion (Args &input,
                              int &cursor_index,
                              int &cursor_char_position,
                              OptionElementVector &opt_element_vector,
                              int match_start_point,
                              int max_return_elements,
                              bool &word_complete,
                              StringList &matches)
    {
        std::string completion_str (input.GetArgumentAtIndex(cursor_index));
        completion_str.erase (cursor_char_position);
        
        CommandCompletions::InvokeCommonCompletionCallbacks (m_interpreter, 
                                                             CommandCompletions::eDiskFileCompletion,
                                                             completion_str.c_str(),
                                                             match_start_point,
                                                             max_return_elements,
                                                             NULL,
                                                             word_complete,
                                                             matches);
        return matches.GetSize();
    }

    virtual Options *
    GetOptions ()
    {
        return &m_options;
    }

protected:

    class CommandOptions : public Options
    {
    public:

        CommandOptions (CommandInterpreter &interpreter) :
            Options (interpreter),
            m_stop_on_error (true),
            m_silent_run (false),
            m_stop_on_continue (true)
        {
        }

        virtual
        ~CommandOptions (){}

        virtual Error
        SetOptionValue (uint32_t option_idx, const char *option_arg)
        {
            Error error;
            const int short_option = m_getopt_table[option_idx].val;
            
            switch (short_option)
            {
                case 'e':
                    error = m_stop_on_error.SetValueFromString(option_arg);
                    break;

                case 'c':
                    error = m_stop_on_continue.SetValueFromString(option_arg);
                    break;

                case 's':
                    error = m_silent_run.SetValueFromString(option_arg);
                    break;

                default:
                    error.SetErrorStringWithFormat ("unrecognized option '%c'", short_option);
                    break;
            }
            
            return error;
        }

        void
        OptionParsingStarting ()
        {
            m_stop_on_error.Clear();
            m_silent_run.Clear();
            m_stop_on_continue.Clear();
        }

        const OptionDefinition*
        GetDefinitions ()
        {
            return g_option_table;
        }

        // Options table: Required for subclasses of Options.

        static OptionDefinition g_option_table[];

        // Instance variables to hold the values for command options.

        OptionValueBoolean m_stop_on_error;
        OptionValueBoolean m_silent_run;
        OptionValueBoolean m_stop_on_continue;
    };
    
    bool
    DoExecute(Args& command, CommandReturnObject &result)
    {
        const size_t argc = command.GetArgumentCount();
        if (argc == 1)
        {
            const char *filename = command.GetArgumentAtIndex(0);

            FileSpec cmd_file (filename, true);
            ExecutionContext *exe_ctx = NULL;  // Just use the default context.
            
            // If any options were set, then use them
            if (m_options.m_stop_on_error.OptionWasSet()    ||
                m_options.m_silent_run.OptionWasSet()       ||
                m_options.m_stop_on_continue.OptionWasSet())
            {
                // Use user set settings
                CommandInterpreterRunOptions options;
                options.SetStopOnContinue(m_options.m_stop_on_continue.GetCurrentValue());
                options.SetStopOnError (m_options.m_stop_on_error.GetCurrentValue());
                options.SetEchoCommands (!m_options.m_silent_run.GetCurrentValue());
                options.SetPrintResults (!m_options.m_silent_run.GetCurrentValue());

                m_interpreter.HandleCommandsFromFile (cmd_file,
                                                      exe_ctx,
                                                      options,
                                                      result);
                
            }
            else
            {
                // No options were set, inherit any settings from nested "command source" commands,
                // or set to sane default settings...
                CommandInterpreterRunOptions options;
                m_interpreter.HandleCommandsFromFile (cmd_file,
                                                      exe_ctx,
                                                      options,
                                                      result);
                
            }
        }
        else
        {
            result.AppendErrorWithFormat("'%s' takes exactly one executable filename argument.\n", GetCommandName());
            result.SetStatus (eReturnStatusFailed);
        }
        return result.Succeeded();

    }
    CommandOptions m_options;    
};

OptionDefinition
CommandObjectCommandsSource::CommandOptions::g_option_table[] =
{
{ LLDB_OPT_SET_ALL, false, "stop-on-error", 'e', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeBoolean,    "If true, stop executing commands on error."},
{ LLDB_OPT_SET_ALL, false, "stop-on-continue", 'c', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeBoolean, "If true, stop executing commands on continue."},
{ LLDB_OPT_SET_ALL, false, "silent-run", 's', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeBoolean, "If true don't echo commands while executing."},
{ 0, false, NULL, 0, 0, NULL, NULL, 0, eArgTypeNone, NULL }
};

#pragma mark CommandObjectCommandsAlias
//-------------------------------------------------------------------------
// CommandObjectCommandsAlias
//-------------------------------------------------------------------------

static const char *g_python_command_instructions =   "Enter your Python command(s). Type 'DONE' to end.\n"
                                                     "You must define a Python function with this signature:\n"
                                                     "def my_command_impl(debugger, args, result, internal_dict):\n";


class CommandObjectCommandsAlias : public CommandObjectRaw
{
    
    
public:
    CommandObjectCommandsAlias (CommandInterpreter &interpreter) :
        CommandObjectRaw (interpreter,
                       "command alias",
                       "Allow users to define their own debugger command abbreviations.",
                       NULL)
    {
        SetHelpLong(
    "'alias' allows the user to create a short-cut or abbreviation for long \n\
    commands, multi-word commands, and commands that take particular options. \n\
    Below are some simple examples of how one might use the 'alias' command: \n\
    \n    'command alias sc script'            // Creates the abbreviation 'sc' for the 'script' \n\
                                         // command. \n\
    'command alias bp breakpoint'        // Creates the abbreviation 'bp' for the 'breakpoint' \n\
                                         // command.  Since breakpoint commands are two-word \n\
                                         // commands, the user will still need to enter the \n\
                                         // second word after 'bp', e.g. 'bp enable' or \n\
                                         // 'bp delete'. \n\
    'command alias bpl breakpoint list'  // Creates the abbreviation 'bpl' for the \n\
                                         // two-word command 'breakpoint list'. \n\
    \nAn alias can include some options for the command, with the values either \n\
    filled in at the time the alias is created, or specified as positional \n\
    arguments, to be filled in when the alias is invoked.  The following example \n\
    shows how to create aliases with options: \n\
    \n\
    'command alias bfl breakpoint set -f %1 -l %2' \n\
    \nThis creates the abbreviation 'bfl' (for break-file-line), with the -f and -l \n\
    options already part of the alias.  So if the user wants to set a breakpoint \n\
    by file and line without explicitly having to use the -f and -l options, the \n\
    user can now use 'bfl' instead.  The '%1' and '%2' are positional placeholders \n\
    for the actual arguments that will be passed when the alias command is used. \n\
    The number in the placeholder refers to the position/order the actual value \n\
    occupies when the alias is used.  All the occurrences of '%1' in the alias \n\
    will be replaced with the first argument, all the occurrences of '%2' in the \n\
    alias will be replaced with the second argument, and so on.  This also allows \n\
    actual arguments to be used multiple times within an alias (see 'process \n\
    launch' example below).  \n\
    Note: the positional arguments must substitute as whole words in the resultant\n\
    command, so you can't at present do something like:\n\
    \n\
    command alias bcppfl breakpoint set -f %1.cpp -l %2\n\
    \n\
    to get the file extension \".cpp\" automatically appended.  For more complex\n\
    aliasing, use the \"command regex\" command instead.\n\
    \nSo in the 'bfl' case, the actual file value will be \n\
    filled in with the first argument following 'bfl' and the actual line number \n\
    value will be filled in with the second argument.  The user would use this \n\
    alias as follows: \n\
    \n    (lldb)  command alias bfl breakpoint set -f %1 -l %2 \n\
    <... some time later ...> \n\
    (lldb)  bfl my-file.c 137 \n\
    \nThis would be the same as if the user had entered \n\
    'breakpoint set -f my-file.c -l 137'. \n\
    \nAnother example: \n\
    \n    (lldb)  command alias pltty  process launch -s -o %1 -e %1 \n\
    (lldb)  pltty /dev/tty0 \n\
           // becomes 'process launch -s -o /dev/tty0 -e /dev/tty0' \n\
    \nIf the user always wanted to pass the same value to a particular option, the \n\
    alias could be defined with that value directly in the alias as a constant, \n\
    rather than using a positional placeholder: \n\
    \n    command alias bl3  breakpoint set -f %1 -l 3  // Always sets a breakpoint on line \n\
                                                   // 3 of whatever file is indicated. \n");

        CommandArgumentEntry arg1;
        CommandArgumentEntry arg2;
        CommandArgumentEntry arg3;
        CommandArgumentData alias_arg;
        CommandArgumentData cmd_arg;
        CommandArgumentData options_arg;
        
        // Define the first (and only) variant of this arg.
        alias_arg.arg_type = eArgTypeAliasName;
        alias_arg.arg_repetition = eArgRepeatPlain;
        
        // There is only one variant this argument could be; put it into the argument entry.
        arg1.push_back (alias_arg);
        
        // Define the first (and only) variant of this arg.
        cmd_arg.arg_type = eArgTypeCommandName;
        cmd_arg.arg_repetition = eArgRepeatPlain;
        
        // There is only one variant this argument could be; put it into the argument entry.
        arg2.push_back (cmd_arg);
        
        // Define the first (and only) variant of this arg.
        options_arg.arg_type = eArgTypeAliasOptions;
        options_arg.arg_repetition = eArgRepeatOptional;
        
        // There is only one variant this argument could be; put it into the argument entry.
        arg3.push_back (options_arg);
        
        // Push the data for the first argument into the m_arguments vector.
        m_arguments.push_back (arg1);
        m_arguments.push_back (arg2);
        m_arguments.push_back (arg3);
    }

    ~CommandObjectCommandsAlias ()
    {
    }

protected:
    virtual bool
    DoExecute (const char *raw_command_line, CommandReturnObject &result)
    {
        Args args (raw_command_line);
        std::string raw_command_string (raw_command_line);
        
        size_t argc = args.GetArgumentCount();
        
        if (argc < 2)
        {
            result.AppendError ("'alias' requires at least two arguments");
            result.SetStatus (eReturnStatusFailed);
            return false;
        }
        
        // Get the alias command.
        
        const std::string alias_command = args.GetArgumentAtIndex (0);
        
        // Strip the new alias name off 'raw_command_string'  (leave it on args, which gets passed to 'Execute', which
        // does the stripping itself.
        size_t pos = raw_command_string.find (alias_command);
        if (pos == 0)
        {
            raw_command_string = raw_command_string.substr (alias_command.size());
            pos = raw_command_string.find_first_not_of (' ');
            if ((pos != std::string::npos) && (pos > 0))
                raw_command_string = raw_command_string.substr (pos);
        }
        else
        {
            result.AppendError ("Error parsing command string.  No alias created.");
            result.SetStatus (eReturnStatusFailed);
            return false;
        }
        
        
        // Verify that the command is alias-able.
        if (m_interpreter.CommandExists (alias_command.c_str()))
        {
            result.AppendErrorWithFormat ("'%s' is a permanent debugger command and cannot be redefined.\n",
                                          alias_command.c_str());
            result.SetStatus (eReturnStatusFailed);
            return false;
        }
        
        // Get CommandObject that is being aliased. The command name is read from the front of raw_command_string.
        // raw_command_string is returned with the name of the command object stripped off the front.
        CommandObject *cmd_obj = m_interpreter.GetCommandObjectForCommand (raw_command_string);
        
        if (!cmd_obj)
        {
            result.AppendErrorWithFormat ("invalid command given to 'alias'. '%s' does not begin with a valid command."
                                          "  No alias created.", raw_command_string.c_str());
            result.SetStatus (eReturnStatusFailed);
            return false;
        }
        else if (!cmd_obj->WantsRawCommandString ())
        {
            // Note that args was initialized with the original command, and has not been updated to this point.
            // Therefore can we pass it to the version of Execute that does not need/expect raw input in the alias.
            return HandleAliasingNormalCommand (args, result);
        }
        else
        {
            return HandleAliasingRawCommand (alias_command, raw_command_string, *cmd_obj, result);
        }
        return result.Succeeded();
    }

    bool
    HandleAliasingRawCommand (const std::string &alias_command, std::string &raw_command_string, CommandObject &cmd_obj, CommandReturnObject &result)
    {
            // Verify & handle any options/arguments passed to the alias command
            
            OptionArgVectorSP option_arg_vector_sp = OptionArgVectorSP (new OptionArgVector);
            OptionArgVector *option_arg_vector = option_arg_vector_sp.get();
            
            CommandObjectSP cmd_obj_sp = m_interpreter.GetCommandSPExact (cmd_obj.GetCommandName(), false);

            if (!m_interpreter.ProcessAliasOptionsArgs (cmd_obj_sp, raw_command_string.c_str(), option_arg_vector_sp))
            {
                result.AppendError ("Unable to create requested alias.\n");
                result.SetStatus (eReturnStatusFailed);
                return false;
            }
            
            // Create the alias
            if (m_interpreter.AliasExists (alias_command.c_str())
                || m_interpreter.UserCommandExists (alias_command.c_str()))
            {
                OptionArgVectorSP temp_option_arg_sp (m_interpreter.GetAliasOptions (alias_command.c_str()));
                if (temp_option_arg_sp.get())
                {
                    if (option_arg_vector->size() == 0)
                        m_interpreter.RemoveAliasOptions (alias_command.c_str());
                }
                result.AppendWarningWithFormat ("Overwriting existing definition for '%s'.\n",
                                                alias_command.c_str());
            }
            
            if (cmd_obj_sp)
            {
                m_interpreter.AddAlias (alias_command.c_str(), cmd_obj_sp);
                if (option_arg_vector->size() > 0)
                    m_interpreter.AddOrReplaceAliasOptions (alias_command.c_str(), option_arg_vector_sp);
                result.SetStatus (eReturnStatusSuccessFinishNoResult);
            }
            else
            {
                result.AppendError ("Unable to create requested alias.\n");
                result.SetStatus (eReturnStatusFailed);
            }
            return result.Succeeded ();
    }
    
    bool
    HandleAliasingNormalCommand (Args& args, CommandReturnObject &result)
    {
        size_t argc = args.GetArgumentCount();

        if (argc < 2)
        {
            result.AppendError ("'alias' requires at least two arguments");
            result.SetStatus (eReturnStatusFailed);
            return false;
        }

        const std::string alias_command = args.GetArgumentAtIndex(0);
        const std::string actual_command = args.GetArgumentAtIndex(1);

        args.Shift();  // Shift the alias command word off the argument vector.
        args.Shift();  // Shift the old command word off the argument vector.

        // Verify that the command is alias'able, and get the appropriate command object.

        if (m_interpreter.CommandExists (alias_command.c_str()))
        {
            result.AppendErrorWithFormat ("'%s' is a permanent debugger command and cannot be redefined.\n",
                                         alias_command.c_str());
            result.SetStatus (eReturnStatusFailed);
        }
        else
        {
             CommandObjectSP command_obj_sp(m_interpreter.GetCommandSPExact (actual_command.c_str(), true));
             CommandObjectSP subcommand_obj_sp;
             bool use_subcommand = false;
             if (command_obj_sp.get())
             {
                 CommandObject *cmd_obj = command_obj_sp.get();
                 CommandObject *sub_cmd_obj = NULL;
                 OptionArgVectorSP option_arg_vector_sp = OptionArgVectorSP (new OptionArgVector);
                 OptionArgVector *option_arg_vector = option_arg_vector_sp.get();

                 while (cmd_obj->IsMultiwordObject() && args.GetArgumentCount() > 0)
                 {
                     if (argc >= 3)
                     {
                         const std::string sub_command = args.GetArgumentAtIndex(0);
                         assert (sub_command.length() != 0);
                         subcommand_obj_sp = cmd_obj->GetSubcommandSP (sub_command.c_str());
                         if (subcommand_obj_sp.get())
                         {
                             sub_cmd_obj = subcommand_obj_sp.get();
                             use_subcommand = true;
                             args.Shift();  // Shift the sub_command word off the argument vector.
                             cmd_obj = sub_cmd_obj;
                         }
                         else
                         {
                             result.AppendErrorWithFormat("'%s' is not a valid sub-command of '%s'.  "
                                                          "Unable to create alias.\n",
                                                          sub_command.c_str(), actual_command.c_str());
                             result.SetStatus (eReturnStatusFailed);
                             return false;
                         }
                     }
                 }

                 // Verify & handle any options/arguments passed to the alias command

                 if (args.GetArgumentCount () > 0)
                 {
                    CommandObjectSP tmp_sp = m_interpreter.GetCommandSPExact (cmd_obj->GetCommandName(), false);
                    if (use_subcommand)
                        tmp_sp = m_interpreter.GetCommandSPExact (sub_cmd_obj->GetCommandName(), false);
                        
                    std::string args_string;
                    args.GetCommandString (args_string);
                    
                    if (!m_interpreter.ProcessAliasOptionsArgs (tmp_sp, args_string.c_str(), option_arg_vector_sp))
                    {
                        result.AppendError ("Unable to create requested alias.\n");
                        result.SetStatus (eReturnStatusFailed);
                        return false;
                    }
                 }

                 // Create the alias.

                 if (m_interpreter.AliasExists (alias_command.c_str())
                     || m_interpreter.UserCommandExists (alias_command.c_str()))
                 {
                     OptionArgVectorSP tmp_option_arg_sp (m_interpreter.GetAliasOptions (alias_command.c_str()));
                     if (tmp_option_arg_sp.get())
                     {
                         if (option_arg_vector->size() == 0)
                             m_interpreter.RemoveAliasOptions (alias_command.c_str());
                     }
                     result.AppendWarningWithFormat ("Overwriting existing definition for '%s'.\n", 
                                                     alias_command.c_str());
                 }

                 if (use_subcommand)
                     m_interpreter.AddAlias (alias_command.c_str(), subcommand_obj_sp);
                 else
                     m_interpreter.AddAlias (alias_command.c_str(), command_obj_sp);
                 if (option_arg_vector->size() > 0)
                     m_interpreter.AddOrReplaceAliasOptions (alias_command.c_str(), option_arg_vector_sp);
                 result.SetStatus (eReturnStatusSuccessFinishNoResult);
             }
             else
             {
                 result.AppendErrorWithFormat ("'%s' is not an existing command.\n", actual_command.c_str());
                 result.SetStatus (eReturnStatusFailed);
                 return false;
             }
        }

        return result.Succeeded();
    }
    
};

#pragma mark CommandObjectCommandsUnalias
//-------------------------------------------------------------------------
// CommandObjectCommandsUnalias
//-------------------------------------------------------------------------

class CommandObjectCommandsUnalias : public CommandObjectParsed
{
public:
    CommandObjectCommandsUnalias (CommandInterpreter &interpreter) :
        CommandObjectParsed (interpreter,
                       "command unalias",
                       "Allow the user to remove/delete a user-defined command abbreviation.",
                       NULL)
    {
        CommandArgumentEntry arg;
        CommandArgumentData alias_arg;
        
        // Define the first (and only) variant of this arg.
        alias_arg.arg_type = eArgTypeAliasName;
        alias_arg.arg_repetition = eArgRepeatPlain;
        
        // There is only one variant this argument could be; put it into the argument entry.
        arg.push_back (alias_arg);
        
        // Push the data for the first argument into the m_arguments vector.
        m_arguments.push_back (arg);
    }

    ~CommandObjectCommandsUnalias()
    {
    }

protected:
    bool
    DoExecute (Args& args, CommandReturnObject &result)
    {
        CommandObject::CommandMap::iterator pos;
        CommandObject *cmd_obj;

        if (args.GetArgumentCount() != 0)
        {
            const char *command_name = args.GetArgumentAtIndex(0);
            cmd_obj = m_interpreter.GetCommandObject(command_name);
            if (cmd_obj)
            {
                if (m_interpreter.CommandExists (command_name))
                {
                    if (cmd_obj->IsRemovable())
                    {
                        result.AppendErrorWithFormat ("'%s' is not an alias, it is a debugger command which can be removed using the 'command delete' command.\n",
                                                      command_name);
                    }
                    else
                    {
                        result.AppendErrorWithFormat ("'%s' is a permanent debugger command and cannot be removed.\n",
                                                      command_name);
                    }
                    result.SetStatus (eReturnStatusFailed);
                }
                else
                {

                    if (m_interpreter.RemoveAlias (command_name) == false)
                    {
                        if (m_interpreter.AliasExists (command_name))
                            result.AppendErrorWithFormat ("Error occurred while attempting to unalias '%s'.\n", 
                                                          command_name);
                        else
                            result.AppendErrorWithFormat ("'%s' is not an existing alias.\n", command_name);
                        result.SetStatus (eReturnStatusFailed);
                    }
                    else
                        result.SetStatus (eReturnStatusSuccessFinishNoResult);
                }
            }
            else
            {
                result.AppendErrorWithFormat ("'%s' is not a known command.\nTry 'help' to see a "
                                              "current list of commands.\n",
                                             command_name);
                result.SetStatus (eReturnStatusFailed);
            }
        }
        else
        {
            result.AppendError ("must call 'unalias' with a valid alias");
            result.SetStatus (eReturnStatusFailed);
        }

        return result.Succeeded();
    }
};

#pragma mark CommandObjectCommandsDelete
//-------------------------------------------------------------------------
// CommandObjectCommandsDelete
//-------------------------------------------------------------------------

class CommandObjectCommandsDelete : public CommandObjectParsed
{
public:
    CommandObjectCommandsDelete (CommandInterpreter &interpreter) :
    CommandObjectParsed (interpreter,
                         "command delete",
                         "Allow the user to delete user-defined regular expression, python or multi-word commands.",
                         NULL)
    {
        CommandArgumentEntry arg;
        CommandArgumentData alias_arg;

        // Define the first (and only) variant of this arg.
        alias_arg.arg_type = eArgTypeCommandName;
        alias_arg.arg_repetition = eArgRepeatPlain;

        // There is only one variant this argument could be; put it into the argument entry.
        arg.push_back (alias_arg);

        // Push the data for the first argument into the m_arguments vector.
        m_arguments.push_back (arg);
    }

    ~CommandObjectCommandsDelete()
    {
    }

protected:
    bool
    DoExecute (Args& args, CommandReturnObject &result)
    {
        CommandObject::CommandMap::iterator pos;

        if (args.GetArgumentCount() != 0)
        {
            const char *command_name = args.GetArgumentAtIndex(0);
            if (m_interpreter.CommandExists (command_name))
            {
                if (m_interpreter.RemoveCommand (command_name))
                {
                    result.SetStatus (eReturnStatusSuccessFinishNoResult);
                }
                else
                {
                    result.AppendErrorWithFormat ("'%s' is a permanent debugger command and cannot be removed.\n",
                                                  command_name);
                    result.SetStatus (eReturnStatusFailed);
                }
            }
            else
            {
                result.AppendErrorWithFormat ("'%s' is not a known command.\nTry 'help' to see a current list of commands.\n",
                                              command_name);
                result.SetStatus (eReturnStatusFailed);
            }
        }
        else
        {
            result.AppendErrorWithFormat ("must call '%s' with one or more valid user defined regular expression, python or multi-word command names", GetCommandName ());
            result.SetStatus (eReturnStatusFailed);
        }

        return result.Succeeded();
    }
};

//-------------------------------------------------------------------------
// CommandObjectCommandsAddRegex
//-------------------------------------------------------------------------
#pragma mark CommandObjectCommandsAddRegex

class CommandObjectCommandsAddRegex :
    public CommandObjectParsed,
    public IOHandlerDelegateMultiline
{
public:
    CommandObjectCommandsAddRegex (CommandInterpreter &interpreter) :
        CommandObjectParsed (interpreter,
                       "command regex",
                       "Allow the user to create a regular expression command.",
                       "command regex <cmd-name> [s/<regex>/<subst>/ ...]"),
        IOHandlerDelegateMultiline ("", IOHandlerDelegate::Completion::LLDBCommand),
        m_options (interpreter)
    {
        SetHelpLong(
"This command allows the user to create powerful regular expression commands\n"
"with substitutions. The regular expressions and substitutions are specified\n"
"using the regular expression substitution format of:\n"
"\n"
"    s/<regex>/<subst>/\n"
"\n"
"<regex> is a regular expression that can use parenthesis to capture regular\n"
"expression input and substitute the captured matches in the output using %1\n"
"for the first match, %2 for the second, and so on.\n"
"\n"
"The regular expressions can all be specified on the command line if more than\n"
"one argument is provided. If just the command name is provided on the command\n"
"line, then the regular expressions and substitutions can be entered on separate\n"
" lines, followed by an empty line to terminate the command definition.\n"
"\n"
"EXAMPLES\n"
"\n"
"The following example will define a regular expression command named 'f' that\n"
"will call 'finish' if there are no arguments, or 'frame select <frame-idx>' if\n"
"a number follows 'f':\n"
"\n"
"    (lldb) command regex f s/^$/finish/ 's/([0-9]+)/frame select %1/'\n"
"\n"
                    );
    }
    
    ~CommandObjectCommandsAddRegex()
    {
    }
    
    
protected:
    
    void
    IOHandlerActivated (IOHandler &io_handler) override
    {
        StreamFileSP output_sp(io_handler.GetOutputStreamFile());
        if (output_sp)
        {
            output_sp->PutCString("Enter one of more sed substitution commands in the form: 's/<regex>/<subst>/'.\nTerminate the substitution list with an empty line.\n");
            output_sp->Flush();
        }
    }

    void
    IOHandlerInputComplete (IOHandler &io_handler, std::string &data) override
    {
        io_handler.SetIsDone(true);
        if (m_regex_cmd_ap.get())
        {
            StringList lines;
            if (lines.SplitIntoLines (data))
            {
                const size_t num_lines = lines.GetSize();
                bool check_only = false;
                for (size_t i=0; i<num_lines; ++i)
                {
                    llvm::StringRef bytes_strref (lines[i]);
                    Error error = AppendRegexSubstitution (bytes_strref, check_only);
                    if (error.Fail())
                    {
                        if (!m_interpreter.GetDebugger().GetCommandInterpreter().GetBatchCommandMode())
                        {
                            StreamSP out_stream = m_interpreter.GetDebugger().GetAsyncOutputStream();
                            out_stream->Printf("error: %s\n", error.AsCString());
                        }
                    }
                }
            }
            if (m_regex_cmd_ap->HasRegexEntries())
            {
                CommandObjectSP cmd_sp (m_regex_cmd_ap.release());
                m_interpreter.AddCommand(cmd_sp->GetCommandName(), cmd_sp, true);
            }
        }
    }

    bool
    DoExecute (Args& command, CommandReturnObject &result) override
    {
        const size_t argc = command.GetArgumentCount();
        if (argc == 0)
        {
            result.AppendError ("usage: 'command regex <command-name> [s/<regex1>/<subst1>/ s/<regex2>/<subst2>/ ...]'\n");
            result.SetStatus (eReturnStatusFailed);
        }
        else
        {   
            Error error;
            const char *name = command.GetArgumentAtIndex(0);
            m_regex_cmd_ap.reset (new CommandObjectRegexCommand (m_interpreter, 
                                                                 name, 
                                                                 m_options.GetHelp (),
                                                                 m_options.GetSyntax (),
                                                                 10,
                                                                 0,
                                                                 true));

            if (argc == 1)
            {
                Debugger &debugger = m_interpreter.GetDebugger();
                bool color_prompt = debugger.GetUseColor();
                const bool multiple_lines = true; // Get multiple lines
                IOHandlerSP io_handler_sp (new IOHandlerEditline (debugger,
                                                                  IOHandler::Type::Other,
                                                                  "lldb-regex", // Name of input reader for history
                                                                  "> ",         // Prompt
                                                                  NULL,         // Continuation prompt
                                                                  multiple_lines,
                                                                  color_prompt,
                                                                  0,            // Don't show line numbers
                                                                  *this));
                
                if (io_handler_sp)
                {
                    debugger.PushIOHandler(io_handler_sp);
                    result.SetStatus (eReturnStatusSuccessFinishNoResult);
                }
            }
            else
            {
                for (size_t arg_idx = 1; arg_idx < argc; ++arg_idx)
                {
                    llvm::StringRef arg_strref (command.GetArgumentAtIndex(arg_idx));
                    bool check_only = false;
                    error = AppendRegexSubstitution (arg_strref, check_only);
                    if (error.Fail())
                        break;
                }
                
                if (error.Success())
                {
                    AddRegexCommandToInterpreter();
                }
            }
            if (error.Fail())
            {
                result.AppendError (error.AsCString());
                result.SetStatus (eReturnStatusFailed);
            }
        }

        return result.Succeeded();
    }
    
    Error
    AppendRegexSubstitution (const llvm::StringRef &regex_sed, bool check_only)
    {
        Error error;
        
        if (m_regex_cmd_ap.get() == NULL)
        {
            error.SetErrorStringWithFormat("invalid regular expression command object for: '%.*s'", 
                                           (int)regex_sed.size(), 
                                           regex_sed.data());
            return error;
        }
    
        size_t regex_sed_size = regex_sed.size();
        
        if (regex_sed_size <= 1)
        {
            error.SetErrorStringWithFormat("regular expression substitution string is too short: '%.*s'", 
                                           (int)regex_sed.size(), 
                                           regex_sed.data());
            return error;
        }

        if (regex_sed[0] != 's')
        {
            error.SetErrorStringWithFormat("regular expression substitution string doesn't start with 's': '%.*s'", 
                                           (int)regex_sed.size(), 
                                           regex_sed.data());
            return error;
        }
        const size_t first_separator_char_pos = 1;
        // use the char that follows 's' as the regex separator character
        // so we can have "s/<regex>/<subst>/" or "s|<regex>|<subst>|"
        const char separator_char = regex_sed[first_separator_char_pos];
        const size_t second_separator_char_pos = regex_sed.find (separator_char, first_separator_char_pos + 1);
        
        if (second_separator_char_pos == std::string::npos)
        {
            error.SetErrorStringWithFormat("missing second '%c' separator char after '%.*s' in '%.*s'",
                                           separator_char, 
                                           (int)(regex_sed.size() - first_separator_char_pos - 1),
                                           regex_sed.data() + (first_separator_char_pos + 1),
                                           (int)regex_sed.size(),
                                           regex_sed.data());
            return error;
        }

        const size_t third_separator_char_pos = regex_sed.find (separator_char, second_separator_char_pos + 1);
        
        if (third_separator_char_pos == std::string::npos)
        {
            error.SetErrorStringWithFormat("missing third '%c' separator char after '%.*s' in '%.*s'",
                                           separator_char, 
                                           (int)(regex_sed.size() - second_separator_char_pos - 1),
                                           regex_sed.data() + (second_separator_char_pos + 1),
                                           (int)regex_sed.size(),
                                           regex_sed.data());
            return error;            
        }

        if (third_separator_char_pos != regex_sed_size - 1)
        {
            // Make sure that everything that follows the last regex 
            // separator char 
            if (regex_sed.find_first_not_of("\t\n\v\f\r ", third_separator_char_pos + 1) != std::string::npos)
            {
                error.SetErrorStringWithFormat("extra data found after the '%.*s' regular expression substitution string: '%.*s'", 
                                               (int)third_separator_char_pos + 1,
                                               regex_sed.data(),
                                               (int)(regex_sed.size() - third_separator_char_pos - 1),
                                               regex_sed.data() + (third_separator_char_pos + 1));
                return error;
            }
            
        }
        else if (first_separator_char_pos + 1 == second_separator_char_pos)
        {
            error.SetErrorStringWithFormat("<regex> can't be empty in 's%c<regex>%c<subst>%c' string: '%.*s'",  
                                           separator_char,
                                           separator_char,
                                           separator_char,
                                           (int)regex_sed.size(), 
                                           regex_sed.data());
            return error;            
        }
        else if (second_separator_char_pos + 1 == third_separator_char_pos)
        {
            error.SetErrorStringWithFormat("<subst> can't be empty in 's%c<regex>%c<subst>%c' string: '%.*s'",   
                                           separator_char,
                                           separator_char,
                                           separator_char,
                                           (int)regex_sed.size(), 
                                           regex_sed.data());
            return error;            
        }

        if (check_only == false)
        {
            std::string regex(regex_sed.substr(first_separator_char_pos + 1, second_separator_char_pos - first_separator_char_pos - 1));
            std::string subst(regex_sed.substr(second_separator_char_pos + 1, third_separator_char_pos - second_separator_char_pos - 1));
            m_regex_cmd_ap->AddRegexCommand (regex.c_str(),
                                             subst.c_str());
        }
        return error;
    }
    
    void
    AddRegexCommandToInterpreter()
    {
        if (m_regex_cmd_ap.get())
        {
            if (m_regex_cmd_ap->HasRegexEntries())
            {
                CommandObjectSP cmd_sp (m_regex_cmd_ap.release());
                m_interpreter.AddCommand(cmd_sp->GetCommandName(), cmd_sp, true);
            }
        }
    }

private:
    std::unique_ptr<CommandObjectRegexCommand> m_regex_cmd_ap;

     class CommandOptions : public Options
     {
     public:
         
         CommandOptions (CommandInterpreter &interpreter) :
            Options (interpreter)
         {
         }
         
         virtual
         ~CommandOptions (){}
         
         virtual Error
         SetOptionValue (uint32_t option_idx, const char *option_arg)
         {
             Error error;
             const int short_option = m_getopt_table[option_idx].val;
             
             switch (short_option)
             {
                 case 'h':
                     m_help.assign (option_arg);
                     break;
                 case 's':
                     m_syntax.assign (option_arg);
                     break;

                 default:
                     error.SetErrorStringWithFormat ("unrecognized option '%c'", short_option);
                     break;
             }
             
             return error;
         }
         
         void
         OptionParsingStarting ()
         {
             m_help.clear();
             m_syntax.clear();
         }
         
         const OptionDefinition*
         GetDefinitions ()
         {
             return g_option_table;
         }
         
         // Options table: Required for subclasses of Options.
         
         static OptionDefinition g_option_table[];
         
         const char *
         GetHelp ()
         {
             if (m_help.empty())
                 return NULL;
             return m_help.c_str();
         }
         const char *
         GetSyntax ()
         {
             if (m_syntax.empty())
                 return NULL;
             return m_syntax.c_str();
         }
         // Instance variables to hold the values for command options.
     protected:
         std::string m_help;
         std::string m_syntax;
     };
          
     Options *
     GetOptions () override
     {
         return &m_options;
     }
     
     CommandOptions m_options;
};

OptionDefinition
CommandObjectCommandsAddRegex::CommandOptions::g_option_table[] =
{
{ LLDB_OPT_SET_1, false, "help"  , 'h', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeNone, "The help text to display for this command."},
{ LLDB_OPT_SET_1, false, "syntax", 's', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeNone, "A syntax string showing the typical usage syntax."},
{ 0             , false,  NULL   , 0  , 0                , NULL, NULL, 0, eArgTypeNone, NULL }
};


class CommandObjectPythonFunction : public CommandObjectRaw
{
private:
    std::string m_function_name;
    ScriptedCommandSynchronicity m_synchro;
    bool m_fetched_help_long;
    
public:
    
    CommandObjectPythonFunction (CommandInterpreter &interpreter,
                                 std::string name,
                                 std::string funct,
                                 std::string help,
                                 ScriptedCommandSynchronicity synch) :
        CommandObjectRaw (interpreter,
                          name.c_str(),
                          NULL,
                          NULL),
        m_function_name(funct),
        m_synchro(synch),
        m_fetched_help_long(false)
    {
        if (!help.empty())
            SetHelp(help.c_str());
        else
        {
            StreamString stream;
            stream.Printf("For more information run 'help %s'",name.c_str());
            SetHelp(stream.GetData());
        }
    }
    
    virtual
    ~CommandObjectPythonFunction ()
    {
    }
    
    virtual bool
    IsRemovable () const
    {
        return true;
    }

    const std::string&
    GetFunctionName ()
    {
        return m_function_name;
    }

    ScriptedCommandSynchronicity
    GetSynchronicity ()
    {
        return m_synchro;
    }
    
    virtual const char *
    GetHelpLong ()
    {
        if (!m_fetched_help_long)
        {
            ScriptInterpreter* scripter = m_interpreter.GetScriptInterpreter();
            if (scripter)
            {
                std::string docstring;
                m_fetched_help_long = scripter->GetDocumentationForItem(m_function_name.c_str(),docstring);
                if (!docstring.empty())
                    SetHelpLong(docstring);
            }
        }
        return CommandObjectRaw::GetHelpLong();
    }
    
protected:
    virtual bool
    DoExecute (const char *raw_command_line, CommandReturnObject &result)
    {
        ScriptInterpreter* scripter = m_interpreter.GetScriptInterpreter();
        
        Error error;
        
        result.SetStatus(eReturnStatusInvalid);
        
        if (!scripter || scripter->RunScriptBasedCommand(m_function_name.c_str(),
                                                         raw_command_line,
                                                         m_synchro,
                                                         result,
                                                         error,
                                                         m_exe_ctx) == false)
        {
            result.AppendError(error.AsCString());
            result.SetStatus(eReturnStatusFailed);
        }
        else
        {
            // Don't change the status if the command already set it...
            if (result.GetStatus() == eReturnStatusInvalid)
            {
                if (result.GetOutputData() == NULL || result.GetOutputData()[0] == '\0')
                    result.SetStatus(eReturnStatusSuccessFinishNoResult);
                else
                    result.SetStatus(eReturnStatusSuccessFinishResult);
            }
        }
        
        return result.Succeeded();
    }
    
};

class CommandObjectScriptingObject : public CommandObjectRaw
{
private:
    lldb::ScriptInterpreterObjectSP m_cmd_obj_sp;
    ScriptedCommandSynchronicity m_synchro;
    
public:
    
    CommandObjectScriptingObject (CommandInterpreter &interpreter,
                                  std::string name,
                                  lldb::ScriptInterpreterObjectSP cmd_obj_sp,
                                  ScriptedCommandSynchronicity synch) :
    CommandObjectRaw (interpreter,
                      name.c_str(),
                      NULL,
                      NULL),
    m_cmd_obj_sp(cmd_obj_sp),
    m_synchro(synch)
    {
        StreamString stream;
        stream.Printf("For more information run 'help %s'",name.c_str());
        SetHelp(stream.GetData());
    }
    
    virtual
    ~CommandObjectScriptingObject ()
    {
    }
    
    virtual bool
    IsRemovable () const
    {
        return true;
    }
    
    lldb::ScriptInterpreterObjectSP
    GetImplementingObject ()
    {
        return m_cmd_obj_sp;
    }
    
    ScriptedCommandSynchronicity
    GetSynchronicity ()
    {
        return m_synchro;
    }
    
    virtual const char *
    GetHelpLong ()
    {
        return CommandObjectRaw::GetHelpLong();
    }
    
protected:
    virtual bool
    DoExecute (const char *raw_command_line, CommandReturnObject &result)
    {
        ScriptInterpreter* scripter = m_interpreter.GetScriptInterpreter();
        
        Error error;
        
        result.SetStatus(eReturnStatusInvalid);
        
        if (!scripter || scripter->RunScriptBasedCommand(m_cmd_obj_sp,
                                                         raw_command_line,
                                                         m_synchro,
                                                         result,
                                                         error,
                                                         m_exe_ctx) == false)
        {
            result.AppendError(error.AsCString());
            result.SetStatus(eReturnStatusFailed);
        }
        else
        {
            // Don't change the status if the command already set it...
            if (result.GetStatus() == eReturnStatusInvalid)
            {
                if (result.GetOutputData() == NULL || result.GetOutputData()[0] == '\0')
                    result.SetStatus(eReturnStatusSuccessFinishNoResult);
                else
                    result.SetStatus(eReturnStatusSuccessFinishResult);
            }
        }
        
        return result.Succeeded();
    }
    
};

//-------------------------------------------------------------------------
// CommandObjectCommandsScriptImport
//-------------------------------------------------------------------------

class CommandObjectCommandsScriptImport : public CommandObjectParsed
{
public:
    CommandObjectCommandsScriptImport (CommandInterpreter &interpreter) :
        CommandObjectParsed (interpreter,
                             "command script import",
                             "Import a scripting module in LLDB.",
                             NULL),
        m_options(interpreter)
    {
        CommandArgumentEntry arg1;
        CommandArgumentData cmd_arg;
        
        // Define the first (and only) variant of this arg.
        cmd_arg.arg_type = eArgTypeFilename;
        cmd_arg.arg_repetition = eArgRepeatPlain;
        
        // There is only one variant this argument could be; put it into the argument entry.
        arg1.push_back (cmd_arg);
        
        // Push the data for the first argument into the m_arguments vector.
        m_arguments.push_back (arg1);
    }
    
    ~CommandObjectCommandsScriptImport ()
    {
    }
    
    virtual int
    HandleArgumentCompletion (Args &input,
                              int &cursor_index,
                              int &cursor_char_position,
                              OptionElementVector &opt_element_vector,
                              int match_start_point,
                              int max_return_elements,
                              bool &word_complete,
                              StringList &matches)
    {
        std::string completion_str (input.GetArgumentAtIndex(cursor_index));
        completion_str.erase (cursor_char_position);
        
        CommandCompletions::InvokeCommonCompletionCallbacks (m_interpreter, 
                                                             CommandCompletions::eDiskFileCompletion,
                                                             completion_str.c_str(),
                                                             match_start_point,
                                                             max_return_elements,
                                                             NULL,
                                                             word_complete,
                                                             matches);
        return matches.GetSize();
    }
    
    virtual Options *
    GetOptions ()
    {
        return &m_options;
    }

protected:
    
    class CommandOptions : public Options
    {
    public:
        
        CommandOptions (CommandInterpreter &interpreter) :
            Options (interpreter)
        {
        }
        
        virtual
        ~CommandOptions (){}
        
        virtual Error
        SetOptionValue (uint32_t option_idx, const char *option_arg)
        {
            Error error;
            const int short_option = m_getopt_table[option_idx].val;
            
            switch (short_option)
            {
                case 'r':
                    m_allow_reload = true;
                    break;
                default:
                    error.SetErrorStringWithFormat ("unrecognized option '%c'", short_option);
                    break;
            }
            
            return error;
        }
        
        void
        OptionParsingStarting ()
        {
            m_allow_reload = true;
        }
        
        const OptionDefinition*
        GetDefinitions ()
        {
            return g_option_table;
        }
        
        // Options table: Required for subclasses of Options.
        
        static OptionDefinition g_option_table[];
        
        // Instance variables to hold the values for command options.
        
        bool m_allow_reload;
    };

    bool
    DoExecute (Args& command, CommandReturnObject &result)
    {
        
        if (m_interpreter.GetDebugger().GetScriptLanguage() != lldb::eScriptLanguagePython)
        {
            result.AppendError ("only scripting language supported for module importing is currently Python");
            result.SetStatus (eReturnStatusFailed);
            return false;
        }
        
        size_t argc = command.GetArgumentCount();
        
        if (argc != 1)
        {
            result.AppendError ("'command script import' requires one argument");
            result.SetStatus (eReturnStatusFailed);
            return false;
        }
        
        std::string path = command.GetArgumentAtIndex(0);
        Error error;
        
        const bool init_session = true;
        // FIXME: this is necessary because CommandObject::CheckRequirements() assumes that
        // commands won't ever be recursively invoked, but it's actually possible to craft
        // a Python script that does other "command script imports" in __lldb_init_module
        // the real fix is to have recursive commands possible with a CommandInvocation object
        // separate from the CommandObject itself, so that recursive command invocations
        // won't stomp on each other (wrt to execution contents, options, and more)
        m_exe_ctx.Clear();
        if (m_interpreter.GetScriptInterpreter()->LoadScriptingModule(path.c_str(),
                                                                      m_options.m_allow_reload,
                                                                      init_session,
                                                                      error))
        {
            result.SetStatus (eReturnStatusSuccessFinishNoResult);
        }
        else
        {
            result.AppendErrorWithFormat("module importing failed: %s", error.AsCString());
            result.SetStatus (eReturnStatusFailed);
        }
        
        return result.Succeeded();
    }
    
    CommandOptions m_options;
};

OptionDefinition
CommandObjectCommandsScriptImport::CommandOptions::g_option_table[] =
{
    { LLDB_OPT_SET_1, false, "allow-reload", 'r', OptionParser::eNoArgument, NULL, NULL, 0, eArgTypeNone,        "Allow the script to be loaded even if it was already loaded before. This argument exists for backwards compatibility, but reloading is always allowed, whether you specify it or not."},
    { 0, false, NULL, 0, 0, NULL, NULL, 0, eArgTypeNone, NULL }
};


//-------------------------------------------------------------------------
// CommandObjectCommandsScriptAdd
//-------------------------------------------------------------------------

class CommandObjectCommandsScriptAdd :
    public CommandObjectParsed,
    public IOHandlerDelegateMultiline
{
public:
    CommandObjectCommandsScriptAdd(CommandInterpreter &interpreter) :
        CommandObjectParsed (interpreter,
                             "command script add",
                             "Add a scripted function as an LLDB command.",
                             NULL),
        IOHandlerDelegateMultiline ("DONE"),
        m_options (interpreter)
    {
        CommandArgumentEntry arg1;
        CommandArgumentData cmd_arg;
        
        // Define the first (and only) variant of this arg.
        cmd_arg.arg_type = eArgTypeCommandName;
        cmd_arg.arg_repetition = eArgRepeatPlain;
        
        // There is only one variant this argument could be; put it into the argument entry.
        arg1.push_back (cmd_arg);
        
        // Push the data for the first argument into the m_arguments vector.
        m_arguments.push_back (arg1);
    }
    
    ~CommandObjectCommandsScriptAdd ()
    {
    }
    
    virtual Options *
    GetOptions ()
    {
        return &m_options;
    }
    
protected:
    
    class CommandOptions : public Options
    {
    public:
        
        CommandOptions (CommandInterpreter &interpreter) :
            Options (interpreter),
            m_class_name(),
            m_funct_name(),
            m_short_help(),
            m_synchronicity(eScriptedCommandSynchronicitySynchronous)
        {
        }
        
        virtual
        ~CommandOptions (){}
        
        virtual Error
        SetOptionValue (uint32_t option_idx, const char *option_arg)
        {
            Error error;
            const int short_option = m_getopt_table[option_idx].val;
            
            switch (short_option)
            {
                case 'f':
                    if (option_arg)
                        m_funct_name.assign(option_arg);
                    break;
                case 'c':
                    if (option_arg)
                        m_class_name.assign(option_arg);
                    break;
                case 'h':
                    if (option_arg)
                        m_short_help.assign(option_arg);
                    break;
                case 's':
                    m_synchronicity = (ScriptedCommandSynchronicity) Args::StringToOptionEnum(option_arg, g_option_table[option_idx].enum_values, 0, error);
                    if (!error.Success())
                        error.SetErrorStringWithFormat ("unrecognized value for synchronicity '%s'", option_arg);
                    break;
                default:
                    error.SetErrorStringWithFormat ("unrecognized option '%c'", short_option);
                    break;
            }
            
            return error;
        }
        
        void
        OptionParsingStarting ()
        {
            m_class_name.clear();
            m_funct_name.clear();
            m_short_help.clear();
            m_synchronicity = eScriptedCommandSynchronicitySynchronous;
        }
        
        const OptionDefinition*
        GetDefinitions ()
        {
            return g_option_table;
        }
        
        // Options table: Required for subclasses of Options.
        
        static OptionDefinition g_option_table[];
        
        // Instance variables to hold the values for command options.
        
        std::string m_class_name;
        std::string m_funct_name;
        std::string m_short_help;
        ScriptedCommandSynchronicity m_synchronicity;
    };

    virtual void
    IOHandlerActivated (IOHandler &io_handler)
    {
        StreamFileSP output_sp(io_handler.GetOutputStreamFile());
        if (output_sp)
        {
            output_sp->PutCString(g_python_command_instructions);
            output_sp->Flush();
        }
    }
    

    virtual void
    IOHandlerInputComplete (IOHandler &io_handler, std::string &data)
    {
        StreamFileSP error_sp = io_handler.GetErrorStreamFile();
        
        ScriptInterpreter *interpreter = m_interpreter.GetScriptInterpreter();
        if (interpreter)
        {
        
            StringList lines;
            lines.SplitIntoLines(data);
            if (lines.GetSize() > 0)
            {
                std::string funct_name_str;
                if (interpreter->GenerateScriptAliasFunction (lines, funct_name_str))
                {
                    if (funct_name_str.empty())
                    {
                        error_sp->Printf ("error: unable to obtain a function name, didn't add python command.\n");
                        error_sp->Flush();
                    }
                    else
                    {
                        // everything should be fine now, let's add this alias
                        
                        CommandObjectSP command_obj_sp(new CommandObjectPythonFunction (m_interpreter,
                                                                                        m_cmd_name,
                                                                                        funct_name_str.c_str(),
                                                                                        m_short_help,
                                                                                        m_synchronicity));
                        
                        if (!m_interpreter.AddUserCommand(m_cmd_name, command_obj_sp, true))
                        {
                            error_sp->Printf ("error: unable to add selected command, didn't add python command.\n");
                            error_sp->Flush();
                        }
                    }
                }
                else
                {
                    error_sp->Printf ("error: unable to create function, didn't add python command.\n");
                    error_sp->Flush();
                }
            }
            else
            {
                error_sp->Printf ("error: empty function, didn't add python command.\n");
                error_sp->Flush();
            }
        }
        else
        {
            error_sp->Printf ("error: script interpreter missing, didn't add python command.\n");
            error_sp->Flush();
        }

        io_handler.SetIsDone(true);
        
        
    }

protected:
    bool
    DoExecute (Args& command, CommandReturnObject &result)
    {
        
        if (m_interpreter.GetDebugger().GetScriptLanguage() != lldb::eScriptLanguagePython)
        {
            result.AppendError ("only scripting language supported for scripted commands is currently Python");
            result.SetStatus (eReturnStatusFailed);
            return false;
        }
        
        size_t argc = command.GetArgumentCount();
        
        if (argc != 1)
        {
            result.AppendError ("'command script add' requires one argument");
            result.SetStatus (eReturnStatusFailed);
            return false;
        }
        
        // Store the options in case we get multi-line input
        m_cmd_name = command.GetArgumentAtIndex(0);
        m_short_help.assign(m_options.m_short_help);
        m_synchronicity = m_options.m_synchronicity;
        
        if (m_options.m_class_name.empty())
        {
            if (m_options.m_funct_name.empty())
            {
                m_interpreter.GetPythonCommandsFromIOHandler ("     ",  // Prompt
                                                              *this,    // IOHandlerDelegate
                                                              true,     // Run IOHandler in async mode
                                                              NULL);    // Baton for the "io_handler" that will be passed back into our IOHandlerDelegate functions
            }
            else
            {
                CommandObjectSP new_cmd(new CommandObjectPythonFunction(m_interpreter,
                                                                        m_cmd_name,
                                                                        m_options.m_funct_name,
                                                                        m_options.m_short_help,
                                                                        m_synchronicity));
                if (m_interpreter.AddUserCommand(m_cmd_name, new_cmd, true))
                {
                    result.SetStatus (eReturnStatusSuccessFinishNoResult);
                }
                else
                {
                    result.AppendError("cannot add command");
                    result.SetStatus (eReturnStatusFailed);
                }
            }
        }
        else
        {
            ScriptInterpreter *interpreter = GetCommandInterpreter().GetScriptInterpreter();
            if (!interpreter)
            {
                result.AppendError("cannot find ScriptInterpreter");
                result.SetStatus(eReturnStatusFailed);
                return false;
            }
            
            auto cmd_obj_sp = interpreter->CreateScriptCommandObject(m_options.m_class_name.c_str());
            if (!cmd_obj_sp)
            {
                result.AppendError("cannot create helper object");
                result.SetStatus(eReturnStatusFailed);
                return false;
            }
            
            CommandObjectSP new_cmd(new CommandObjectScriptingObject(m_interpreter,
                                                                     m_cmd_name,
                                                                     cmd_obj_sp,
                                                                     m_synchronicity));
            if (m_interpreter.AddUserCommand(m_cmd_name, new_cmd, true))
            {
                result.SetStatus (eReturnStatusSuccessFinishNoResult);
            }
            else
            {
                result.AppendError("cannot add command");
                result.SetStatus (eReturnStatusFailed);
            }
        }

        return result.Succeeded();
        
    }
    
    CommandOptions m_options;
    std::string m_cmd_name;
    std::string m_short_help;
    ScriptedCommandSynchronicity m_synchronicity;
};

static OptionEnumValueElement g_script_synchro_type[] =
{
    { eScriptedCommandSynchronicitySynchronous,      "synchronous",       "Run synchronous"},
    { eScriptedCommandSynchronicityAsynchronous,     "asynchronous",      "Run asynchronous"},
    { eScriptedCommandSynchronicityCurrentValue,     "current",           "Do not alter current setting"},
    { 0, NULL, NULL }
};

OptionDefinition
CommandObjectCommandsScriptAdd::CommandOptions::g_option_table[] =
{
    { LLDB_OPT_SET_1, false, "function", 'f', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypePythonFunction,        "Name of the Python function to bind to this command name."},
    { LLDB_OPT_SET_2, false, "class", 'c', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypePythonClass,        "Name of the Python class to bind to this command name."},
    { LLDB_OPT_SET_ALL, false, "help"  , 'h', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeHelpText, "The help text to display for this command."},
    { LLDB_OPT_SET_ALL, false, "synchronicity", 's', OptionParser::eRequiredArgument, NULL, g_script_synchro_type, 0, eArgTypeScriptedCommandSynchronicity,        "Set the synchronicity of this command's executions with regard to LLDB event system."},
    { 0, false, NULL, 0, 0, NULL, NULL, 0, eArgTypeNone, NULL }
};

//-------------------------------------------------------------------------
// CommandObjectCommandsScriptList
//-------------------------------------------------------------------------

class CommandObjectCommandsScriptList : public CommandObjectParsed
{
private:

public:
    CommandObjectCommandsScriptList(CommandInterpreter &interpreter) :
    CommandObjectParsed (interpreter,
                   "command script list",
                   "List defined scripted commands.",
                   NULL)
    {
    }
    
    ~CommandObjectCommandsScriptList ()
    {
    }
    
    bool
    DoExecute (Args& command, CommandReturnObject &result)
    {
        
        m_interpreter.GetHelp(result,
                              CommandInterpreter::eCommandTypesUserDef);
        
        result.SetStatus (eReturnStatusSuccessFinishResult);
        
        return true;
        
        
    }
};

//-------------------------------------------------------------------------
// CommandObjectCommandsScriptClear
//-------------------------------------------------------------------------

class CommandObjectCommandsScriptClear : public CommandObjectParsed
{
private:
    
public:
    CommandObjectCommandsScriptClear(CommandInterpreter &interpreter) :
        CommandObjectParsed (interpreter,
                             "command script clear",
                             "Delete all scripted commands.",
                             NULL)
    {
    }
    
    ~CommandObjectCommandsScriptClear ()
    {
    }
    
protected:
    bool
    DoExecute (Args& command, CommandReturnObject &result)
    {
        
        m_interpreter.RemoveAllUser();
        
        result.SetStatus (eReturnStatusSuccessFinishResult);
        
        return true;
    }
};

//-------------------------------------------------------------------------
// CommandObjectCommandsScriptDelete
//-------------------------------------------------------------------------

class CommandObjectCommandsScriptDelete : public CommandObjectParsed
{
public:
    CommandObjectCommandsScriptDelete(CommandInterpreter &interpreter) :
        CommandObjectParsed (interpreter,
                             "command script delete",
                             "Delete a scripted command.",
                             NULL)
    {
        CommandArgumentEntry arg1;
        CommandArgumentData cmd_arg;
        
        // Define the first (and only) variant of this arg.
        cmd_arg.arg_type = eArgTypeCommandName;
        cmd_arg.arg_repetition = eArgRepeatPlain;
        
        // There is only one variant this argument could be; put it into the argument entry.
        arg1.push_back (cmd_arg);
        
        // Push the data for the first argument into the m_arguments vector.
        m_arguments.push_back (arg1);
    }
    
    ~CommandObjectCommandsScriptDelete ()
    {
    }
    
protected:
    bool
    DoExecute (Args& command, CommandReturnObject &result)
    {
        
        size_t argc = command.GetArgumentCount();
        
        if (argc != 1)
        {
            result.AppendError ("'command script delete' requires one argument");
            result.SetStatus (eReturnStatusFailed);
            return false;
        }
        
        const char* cmd_name = command.GetArgumentAtIndex(0);
        
        if (cmd_name && *cmd_name && m_interpreter.HasUserCommands() && m_interpreter.UserCommandExists(cmd_name))
        {
            m_interpreter.RemoveUser(cmd_name);
            result.SetStatus (eReturnStatusSuccessFinishResult);
        }
        else
        {
            result.AppendErrorWithFormat ("command %s not found", cmd_name);
            result.SetStatus (eReturnStatusFailed);
        }
        
        return result.Succeeded();
        
    }
};

#pragma mark CommandObjectMultiwordCommandsScript

//-------------------------------------------------------------------------
// CommandObjectMultiwordCommandsScript
//-------------------------------------------------------------------------

class CommandObjectMultiwordCommandsScript : public CommandObjectMultiword
{
public:
    CommandObjectMultiwordCommandsScript (CommandInterpreter &interpreter) :
    CommandObjectMultiword (interpreter,
                            "command script",
                            "A set of commands for managing or customizing script commands.",
                            "command script <subcommand> [<subcommand-options>]")
    {
        LoadSubCommand ("add",    CommandObjectSP (new CommandObjectCommandsScriptAdd (interpreter)));
        LoadSubCommand ("delete", CommandObjectSP (new CommandObjectCommandsScriptDelete (interpreter)));
        LoadSubCommand ("clear",  CommandObjectSP (new CommandObjectCommandsScriptClear (interpreter)));
        LoadSubCommand ("list",   CommandObjectSP (new CommandObjectCommandsScriptList (interpreter)));
        LoadSubCommand ("import", CommandObjectSP (new CommandObjectCommandsScriptImport (interpreter)));
    }

    ~CommandObjectMultiwordCommandsScript ()
    {
    }
    
};


#pragma mark CommandObjectMultiwordCommands

//-------------------------------------------------------------------------
// CommandObjectMultiwordCommands
//-------------------------------------------------------------------------

CommandObjectMultiwordCommands::CommandObjectMultiwordCommands (CommandInterpreter &interpreter) :
    CommandObjectMultiword (interpreter,
                            "command",
                            "A set of commands for managing or customizing the debugger commands.",
                            "command <subcommand> [<subcommand-options>]")
{
    LoadSubCommand ("source",  CommandObjectSP (new CommandObjectCommandsSource (interpreter)));
    LoadSubCommand ("alias",   CommandObjectSP (new CommandObjectCommandsAlias (interpreter)));
    LoadSubCommand ("unalias", CommandObjectSP (new CommandObjectCommandsUnalias (interpreter)));
    LoadSubCommand ("delete",  CommandObjectSP (new CommandObjectCommandsDelete (interpreter)));
    LoadSubCommand ("regex",   CommandObjectSP (new CommandObjectCommandsAddRegex (interpreter)));
    LoadSubCommand ("history", CommandObjectSP (new CommandObjectCommandsHistory (interpreter)));
    LoadSubCommand ("script",  CommandObjectSP (new CommandObjectMultiwordCommandsScript (interpreter)));
}

CommandObjectMultiwordCommands::~CommandObjectMultiwordCommands ()
{
}