xref: /llvm-project-15.0.7/lldb/source/Commands/CommandObjectBreakpointCommand.cpp (revision b9c1b51e)

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

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "CommandObjectBreakpointCommand.h"
#include "CommandObjectBreakpoint.h"
#include "lldb/Breakpoint/Breakpoint.h"
#include "lldb/Breakpoint/BreakpointIDList.h"
#include "lldb/Breakpoint/BreakpointLocation.h"
#include "lldb/Breakpoint/StoppointCallbackContext.h"
#include "lldb/Core/IOHandler.h"
#include "lldb/Core/State.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"

using namespace lldb;
using namespace lldb_private;

//-------------------------------------------------------------------------
// CommandObjectBreakpointCommandAdd
//-------------------------------------------------------------------------

class CommandObjectBreakpointCommandAdd : public CommandObjectParsed,
                                          public IOHandlerDelegateMultiline {
public:
  CommandObjectBreakpointCommandAdd(CommandInterpreter &interpreter)
      : CommandObjectParsed(interpreter, "add",
                            "Add LLDB commands to a breakpoint, to be executed "
                            "whenever the breakpoint is hit."
                            "  If no breakpoint is specified, adds the "
                            "commands to the last created breakpoint.",
                            nullptr),
        IOHandlerDelegateMultiline("DONE",
                                   IOHandlerDelegate::Completion::LLDBCommand),
        m_options() {
    SetHelpLong(
        R"(
General information about entering breakpoint commands
------------------------------------------------------

)"
        "This command will prompt for commands to be executed when the specified \
breakpoint is hit.  Each command is typed on its own line following the '> ' \
prompt until 'DONE' is entered."
        R"(

)"
        "Syntactic errors may not be detected when initially entered, and many \
malformed commands can silently fail when executed.  If your breakpoint commands \
do not appear to be executing, double-check the command syntax."
        R"(

)"
        "Note: You may enter any debugger command exactly as you would at the debugger \
prompt.  There is no limit to the number of commands supplied, but do NOT enter \
more than one command per line."
        R"(

Special information about PYTHON breakpoint commands
----------------------------------------------------

)"
        "You may enter either one or more lines of Python, including function \
definitions or calls to functions that will have been imported by the time \
the code executes.  Single line breakpoint commands will be interpreted 'as is' \
when the breakpoint is hit.  Multiple lines of Python will be wrapped in a \
generated function, and a call to the function will be attached to the breakpoint."
        R"(

This auto-generated function is passed in three arguments:

    frame:  an lldb.SBFrame object for the frame which hit breakpoint.

    bp_loc: an lldb.SBBreakpointLocation object that represents the breakpoint location that was hit.

    dict:   the python session dictionary hit.

)"
        "When specifying a python function with the --python-function option, you need \
to supply the function name prepended by the module name:"
        R"(

    --python-function myutils.breakpoint_callback

The function itself must have the following prototype:

def breakpoint_callback(frame, bp_loc, dict):
  # Your code goes here

)"
        "The arguments are the same as the arguments passed to generated functions as \
described above.  Note that the global variable 'lldb.frame' will NOT be updated when \
this function is called, so be sure to use the 'frame' argument. The 'frame' argument \
can get you to the thread via frame.GetThread(), the thread can get you to the \
process via thread.GetProcess(), and the process can get you back to the target \
via process.GetTarget()."
        R"(

)"
        "Important Note: As Python code gets collected into functions, access to global \
variables requires explicit scoping using the 'global' keyword.  Be sure to use correct \
Python syntax, including indentation, when entering Python breakpoint commands."
        R"(

Example Python one-line breakpoint command:

(lldb) breakpoint command add -s python 1
Enter your Python command(s). Type 'DONE' to end.
> print "Hit this breakpoint!"
> DONE

As a convenience, this also works for a short Python one-liner:

(lldb) breakpoint command add -s python 1 -o 'import time; print time.asctime()'
(lldb) run
Launching '.../a.out'  (x86_64)
(lldb) Fri Sep 10 12:17:45 2010
Process 21778 Stopped
* thread #1: tid = 0x2e03, 0x0000000100000de8 a.out`c + 7 at main.c:39, stop reason = breakpoint 1.1, queue = com.apple.main-thread
  36
  37   	int c(int val)
  38   	{
  39 ->	    return val + 3;
  40   	}
  41
  42   	int main (int argc, char const *argv[])

Example multiple line Python breakpoint command:

(lldb) breakpoint command add -s p 1
Enter your Python command(s). Type 'DONE' to end.
> global bp_count
> bp_count = bp_count + 1
> print "Hit this breakpoint " + repr(bp_count) + " times!"
> DONE

Example multiple line Python breakpoint command, using function definition:

(lldb) breakpoint command add -s python 1
Enter your Python command(s). Type 'DONE' to end.
> def breakpoint_output (bp_no):
>     out_string = "Hit breakpoint number " + repr (bp_no)
>     print out_string
>     return True
> breakpoint_output (1)
> DONE

)"
        "In this case, since there is a reference to a global variable, \
'bp_count', you will also need to make sure 'bp_count' exists and is \
initialized:"
        R"(

(lldb) script
>>> bp_count = 0
>>> quit()

)"
        "Your Python code, however organized, can optionally return a value.  \
If the returned value is False, that tells LLDB not to stop at the breakpoint \
to which the code is associated. Returning anything other than False, or even \
returning None, or even omitting a return statement entirely, will cause \
LLDB to stop."
        R"(

)"
        "Final Note: A warning that no breakpoint command was generated when there \
are no syntax errors may indicate that a function was declared but never called.");

    CommandArgumentEntry arg;
    CommandArgumentData bp_id_arg;

    // Define the first (and only) variant of this arg.
    bp_id_arg.arg_type = eArgTypeBreakpointID;
    bp_id_arg.arg_repetition = eArgRepeatOptional;

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

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

  ~CommandObjectBreakpointCommandAdd() override = default;

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

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

  void IOHandlerInputComplete(IOHandler &io_handler,
                              std::string &line) override {
    io_handler.SetIsDone(true);

    std::vector<BreakpointOptions *> *bp_options_vec =
        (std::vector<BreakpointOptions *> *)io_handler.GetUserData();
    for (BreakpointOptions *bp_options : *bp_options_vec) {
      if (!bp_options)
        continue;

      std::unique_ptr<BreakpointOptions::CommandData> data_ap(
          new BreakpointOptions::CommandData());
      if (data_ap) {
        data_ap->user_source.SplitIntoLines(line.c_str(), line.size());
        BatonSP baton_sp(
            new BreakpointOptions::CommandBaton(data_ap.release()));
        bp_options->SetCallback(BreakpointOptionsCallbackFunction, baton_sp);
      }
    }
  }

  void CollectDataForBreakpointCommandCallback(
      std::vector<BreakpointOptions *> &bp_options_vec,
      CommandReturnObject &result) {
    m_interpreter.GetLLDBCommandsFromIOHandler(
        "> ",             // Prompt
        *this,            // IOHandlerDelegate
        true,             // Run IOHandler in async mode
        &bp_options_vec); // Baton for the "io_handler" that will be passed back
                          // into our IOHandlerDelegate functions
  }

  /// Set a one-liner as the callback for the breakpoint.
  void
  SetBreakpointCommandCallback(std::vector<BreakpointOptions *> &bp_options_vec,
                               const char *oneliner) {
    for (auto bp_options : bp_options_vec) {
      std::unique_ptr<BreakpointOptions::CommandData> data_ap(
          new BreakpointOptions::CommandData());

      // It's necessary to set both user_source and script_source to the
      // oneliner.
      // The former is used to generate callback description (as in breakpoint
      // command list)
      // while the latter is used for Python to interpret during the actual
      // callback.
      data_ap->user_source.AppendString(oneliner);
      data_ap->script_source.assign(oneliner);
      data_ap->stop_on_error = m_options.m_stop_on_error;

      BatonSP baton_sp(new BreakpointOptions::CommandBaton(data_ap.release()));
      bp_options->SetCallback(BreakpointOptionsCallbackFunction, baton_sp);
    }
  }

  static bool BreakpointOptionsCallbackFunction(
      void *baton, StoppointCallbackContext *context, lldb::user_id_t break_id,
      lldb::user_id_t break_loc_id) {
    bool ret_value = true;
    if (baton == nullptr)
      return true;

    BreakpointOptions::CommandData *data =
        (BreakpointOptions::CommandData *)baton;
    StringList &commands = data->user_source;

    if (commands.GetSize() > 0) {
      ExecutionContext exe_ctx(context->exe_ctx_ref);
      Target *target = exe_ctx.GetTargetPtr();
      if (target) {
        CommandReturnObject result;
        Debugger &debugger = target->GetDebugger();
        // Rig up the results secondary output stream to the debugger's, so the
        // output will come out synchronously
        // if the debugger is set up that way.

        StreamSP output_stream(debugger.GetAsyncOutputStream());
        StreamSP error_stream(debugger.GetAsyncErrorStream());
        result.SetImmediateOutputStream(output_stream);
        result.SetImmediateErrorStream(error_stream);

        CommandInterpreterRunOptions options;
        options.SetStopOnContinue(true);
        options.SetStopOnError(data->stop_on_error);
        options.SetEchoCommands(true);
        options.SetPrintResults(true);
        options.SetAddToHistory(false);

        debugger.GetCommandInterpreter().HandleCommands(commands, &exe_ctx,
                                                        options, result);
        result.GetImmediateOutputStream()->Flush();
        result.GetImmediateErrorStream()->Flush();
      }
    }
    return ret_value;
  }

  class CommandOptions : public Options {
  public:
    CommandOptions()
        : Options(), m_use_commands(false), m_use_script_language(false),
          m_script_language(eScriptLanguageNone), m_use_one_liner(false),
          m_one_liner(), m_function_name() {}

    ~CommandOptions() override = default;

    Error SetOptionValue(uint32_t option_idx, const char *option_arg,
                         ExecutionContext *execution_context) override {
      Error error;
      const int short_option = m_getopt_table[option_idx].val;

      switch (short_option) {
      case 'o':
        m_use_one_liner = true;
        m_one_liner = option_arg;
        break;

      case 's':
        m_script_language = (lldb::ScriptLanguage)Args::StringToOptionEnum(
            option_arg, g_option_table[option_idx].enum_values,
            eScriptLanguageNone, error);

        if (m_script_language == eScriptLanguagePython ||
            m_script_language == eScriptLanguageDefault) {
          m_use_script_language = true;
        } else {
          m_use_script_language = false;
        }
        break;

      case 'e': {
        bool success = false;
        m_stop_on_error = Args::StringToBoolean(option_arg, false, &success);
        if (!success)
          error.SetErrorStringWithFormat(
              "invalid value for stop-on-error: \"%s\"", option_arg);
      } break;

      case 'F':
        m_use_one_liner = false;
        m_use_script_language = true;
        m_function_name.assign(option_arg);
        break;

      case 'D':
        m_use_dummy = true;
        break;

      default:
        break;
      }
      return error;
    }

    void OptionParsingStarting(ExecutionContext *execution_context) override {
      m_use_commands = true;
      m_use_script_language = false;
      m_script_language = eScriptLanguageNone;

      m_use_one_liner = false;
      m_stop_on_error = true;
      m_one_liner.clear();
      m_function_name.clear();
      m_use_dummy = false;
    }

    const OptionDefinition *GetDefinitions() override { 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_use_commands;
    bool m_use_script_language;
    lldb::ScriptLanguage m_script_language;

    // Instance variables to hold the values for one_liner options.
    bool m_use_one_liner;
    std::string m_one_liner;
    bool m_stop_on_error;
    std::string m_function_name;
    bool m_use_dummy;
  };

protected:
  bool DoExecute(Args &command, CommandReturnObject &result) override {
    Target *target = GetSelectedOrDummyTarget(m_options.m_use_dummy);

    if (target == nullptr) {
      result.AppendError("There is not a current executable; there are no "
                         "breakpoints to which to add commands");
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    const BreakpointList &breakpoints = target->GetBreakpointList();
    size_t num_breakpoints = breakpoints.GetSize();

    if (num_breakpoints == 0) {
      result.AppendError("No breakpoints exist to have commands added");
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    if (!m_options.m_use_script_language &&
        !m_options.m_function_name.empty()) {
      result.AppendError("need to enable scripting to have a function run as a "
                         "breakpoint command");
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    BreakpointIDList valid_bp_ids;
    CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
        command, target, result, &valid_bp_ids);

    m_bp_options_vec.clear();

    if (result.Succeeded()) {
      const size_t count = valid_bp_ids.GetSize();

      for (size_t i = 0; i < count; ++i) {
        BreakpointID cur_bp_id = valid_bp_ids.GetBreakpointIDAtIndex(i);
        if (cur_bp_id.GetBreakpointID() != LLDB_INVALID_BREAK_ID) {
          Breakpoint *bp =
              target->GetBreakpointByID(cur_bp_id.GetBreakpointID()).get();
          BreakpointOptions *bp_options = nullptr;
          if (cur_bp_id.GetLocationID() == LLDB_INVALID_BREAK_ID) {
            // This breakpoint does not have an associated location.
            bp_options = bp->GetOptions();
          } else {
            BreakpointLocationSP bp_loc_sp(
                bp->FindLocationByID(cur_bp_id.GetLocationID()));
            // This breakpoint does have an associated location.
            // Get its breakpoint options.
            if (bp_loc_sp)
              bp_options = bp_loc_sp->GetLocationOptions();
          }
          if (bp_options)
            m_bp_options_vec.push_back(bp_options);
        }
      }

      // If we are using script language, get the script interpreter
      // in order to set or collect command callback.  Otherwise, call
      // the methods associated with this object.
      if (m_options.m_use_script_language) {
        ScriptInterpreter *script_interp = m_interpreter.GetScriptInterpreter();
        // Special handling for one-liner specified inline.
        if (m_options.m_use_one_liner) {
          script_interp->SetBreakpointCommandCallback(
              m_bp_options_vec, m_options.m_one_liner.c_str());
        } else if (!m_options.m_function_name.empty()) {
          script_interp->SetBreakpointCommandCallbackFunction(
              m_bp_options_vec, m_options.m_function_name.c_str());
        } else {
          script_interp->CollectDataForBreakpointCommandCallback(
              m_bp_options_vec, result);
        }
      } else {
        // Special handling for one-liner specified inline.
        if (m_options.m_use_one_liner)
          SetBreakpointCommandCallback(m_bp_options_vec,
                                       m_options.m_one_liner.c_str());
        else
          CollectDataForBreakpointCommandCallback(m_bp_options_vec, result);
      }
    }

    return result.Succeeded();
  }

private:
  CommandOptions m_options;
  std::vector<BreakpointOptions *> m_bp_options_vec; // This stores the
                                                     // breakpoint options that
                                                     // we are currently
  // collecting commands for.  In the CollectData... calls we need
  // to hand this off to the IOHandler, which may run asynchronously.
  // So we have to have some way to keep it alive, and not leak it.
  // Making it an ivar of the command object, which never goes away
  // achieves this.  Note that if we were able to run
  // the same command concurrently in one interpreter we'd have to
  // make this "per invocation".  But there are many more reasons
  // why it is not in general safe to do that in lldb at present,
  // so it isn't worthwhile to come up with a more complex mechanism
  // to address this particular weakness right now.
  static const char *g_reader_instructions;
};

const char *CommandObjectBreakpointCommandAdd::g_reader_instructions =
    "Enter your debugger command(s).  Type 'DONE' to end.\n";

// FIXME: "script-type" needs to have its contents determined dynamically, so
// somebody can add a new scripting
// language to lldb and have it pickable here without having to change this
// enumeration by hand and rebuild lldb proper.

static OptionEnumValueElement g_script_option_enumeration[4] = {
    {eScriptLanguageNone, "command",
     "Commands are in the lldb command interpreter language"},
    {eScriptLanguagePython, "python", "Commands are in the Python language."},
    {eSortOrderByName, "default-script",
     "Commands are in the default scripting language."},
    {0, nullptr, nullptr}};

OptionDefinition
    CommandObjectBreakpointCommandAdd::CommandOptions::g_option_table[] = {
        // clang-format off
  {LLDB_OPT_SET_1,   false, "one-liner",         'o', OptionParser::eRequiredArgument, nullptr, nullptr,                     0, eArgTypeOneLiner,       "Specify a one-line breakpoint command inline. Be sure to surround it with quotes." },
  {LLDB_OPT_SET_ALL, false, "stop-on-error",     'e', OptionParser::eRequiredArgument, nullptr, nullptr,                     0, eArgTypeBoolean,        "Specify whether breakpoint command execution should terminate on error." },
  {LLDB_OPT_SET_ALL, false, "script-type",       's', OptionParser::eRequiredArgument, nullptr, g_script_option_enumeration, 0, eArgTypeNone,           "Specify the language for the commands - if none is specified, the lldb command interpreter will be used."},
  {LLDB_OPT_SET_2,   false, "python-function",   'F', OptionParser::eRequiredArgument, nullptr, nullptr,                     0, eArgTypePythonFunction, "Give the name of a Python function to run as command for this breakpoint. Be sure to give a module name if appropriate."},
  {LLDB_OPT_SET_ALL, false, "dummy-breakpoints", 'D', OptionParser::eNoArgument,       nullptr, nullptr,                     0, eArgTypeNone,           "Sets Dummy breakpoints - i.e. breakpoints set before a file is provided, which prime new targets."},
  {0, false, nullptr, 0, 0, nullptr, nullptr, 0, eArgTypeNone, nullptr}
        // clang-format on
};

//-------------------------------------------------------------------------
// CommandObjectBreakpointCommandDelete
//-------------------------------------------------------------------------

class CommandObjectBreakpointCommandDelete : public CommandObjectParsed {
public:
  CommandObjectBreakpointCommandDelete(CommandInterpreter &interpreter)
      : CommandObjectParsed(interpreter, "delete",
                            "Delete the set of commands from a breakpoint.",
                            nullptr),
        m_options() {
    CommandArgumentEntry arg;
    CommandArgumentData bp_id_arg;

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

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

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

  ~CommandObjectBreakpointCommandDelete() override = default;

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

  class CommandOptions : public Options {
  public:
    CommandOptions() : Options(), m_use_dummy(false) {}

    ~CommandOptions() override = default;

    Error SetOptionValue(uint32_t option_idx, const char *option_arg,
                         ExecutionContext *execution_context) override {
      Error error;
      const int short_option = m_getopt_table[option_idx].val;

      switch (short_option) {
      case 'D':
        m_use_dummy = true;
        break;

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

      return error;
    }

    void OptionParsingStarting(ExecutionContext *execution_context) override {
      m_use_dummy = false;
    }

    const OptionDefinition *GetDefinitions() override { 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_use_dummy;
  };

protected:
  bool DoExecute(Args &command, CommandReturnObject &result) override {
    Target *target = GetSelectedOrDummyTarget(m_options.m_use_dummy);

    if (target == nullptr) {
      result.AppendError("There is not a current executable; there are no "
                         "breakpoints from which to delete commands");
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    const BreakpointList &breakpoints = target->GetBreakpointList();
    size_t num_breakpoints = breakpoints.GetSize();

    if (num_breakpoints == 0) {
      result.AppendError("No breakpoints exist to have commands deleted");
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    if (command.GetArgumentCount() == 0) {
      result.AppendError(
          "No breakpoint specified from which to delete the commands");
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    BreakpointIDList valid_bp_ids;
    CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
        command, target, result, &valid_bp_ids);

    if (result.Succeeded()) {
      const size_t count = valid_bp_ids.GetSize();
      for (size_t i = 0; i < count; ++i) {
        BreakpointID cur_bp_id = valid_bp_ids.GetBreakpointIDAtIndex(i);
        if (cur_bp_id.GetBreakpointID() != LLDB_INVALID_BREAK_ID) {
          Breakpoint *bp =
              target->GetBreakpointByID(cur_bp_id.GetBreakpointID()).get();
          if (cur_bp_id.GetLocationID() != LLDB_INVALID_BREAK_ID) {
            BreakpointLocationSP bp_loc_sp(
                bp->FindLocationByID(cur_bp_id.GetLocationID()));
            if (bp_loc_sp)
              bp_loc_sp->ClearCallback();
            else {
              result.AppendErrorWithFormat("Invalid breakpoint ID: %u.%u.\n",
                                           cur_bp_id.GetBreakpointID(),
                                           cur_bp_id.GetLocationID());
              result.SetStatus(eReturnStatusFailed);
              return false;
            }
          } else {
            bp->ClearCallback();
          }
        }
      }
    }
    return result.Succeeded();
  }

private:
  CommandOptions m_options;
};

OptionDefinition
    CommandObjectBreakpointCommandDelete::CommandOptions::g_option_table[] = {
        // clang-format off
  {LLDB_OPT_SET_1, false, "dummy-breakpoints", 'D', OptionParser::eNoArgument, nullptr, nullptr, 0, eArgTypeNone, "Delete commands from Dummy breakpoints - i.e. breakpoints set before a file is provided, which prime new targets."},
  {0, false, nullptr, 0, 0, nullptr, nullptr, 0, eArgTypeNone, nullptr}
        // clang-format on
};

//-------------------------------------------------------------------------
// CommandObjectBreakpointCommandList
//-------------------------------------------------------------------------

class CommandObjectBreakpointCommandList : public CommandObjectParsed {
public:
  CommandObjectBreakpointCommandList(CommandInterpreter &interpreter)
      : CommandObjectParsed(interpreter, "list", "List the script or set of "
                                                 "commands to be executed when "
                                                 "the breakpoint is hit.",
                            nullptr) {
    CommandArgumentEntry arg;
    CommandArgumentData bp_id_arg;

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

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

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

  ~CommandObjectBreakpointCommandList() override = default;

protected:
  bool DoExecute(Args &command, CommandReturnObject &result) override {
    Target *target = m_interpreter.GetDebugger().GetSelectedTarget().get();

    if (target == nullptr) {
      result.AppendError("There is not a current executable; there are no "
                         "breakpoints for which to list commands");
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    const BreakpointList &breakpoints = target->GetBreakpointList();
    size_t num_breakpoints = breakpoints.GetSize();

    if (num_breakpoints == 0) {
      result.AppendError("No breakpoints exist for which to list commands");
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    if (command.GetArgumentCount() == 0) {
      result.AppendError(
          "No breakpoint specified for which to list the commands");
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    BreakpointIDList valid_bp_ids;
    CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
        command, target, result, &valid_bp_ids);

    if (result.Succeeded()) {
      const size_t count = valid_bp_ids.GetSize();
      for (size_t i = 0; i < count; ++i) {
        BreakpointID cur_bp_id = valid_bp_ids.GetBreakpointIDAtIndex(i);
        if (cur_bp_id.GetBreakpointID() != LLDB_INVALID_BREAK_ID) {
          Breakpoint *bp =
              target->GetBreakpointByID(cur_bp_id.GetBreakpointID()).get();

          if (bp) {
            const BreakpointOptions *bp_options = nullptr;
            if (cur_bp_id.GetLocationID() != LLDB_INVALID_BREAK_ID) {
              BreakpointLocationSP bp_loc_sp(
                  bp->FindLocationByID(cur_bp_id.GetLocationID()));
              if (bp_loc_sp)
                bp_options = bp_loc_sp->GetOptionsNoCreate();
              else {
                result.AppendErrorWithFormat("Invalid breakpoint ID: %u.%u.\n",
                                             cur_bp_id.GetBreakpointID(),
                                             cur_bp_id.GetLocationID());
                result.SetStatus(eReturnStatusFailed);
                return false;
              }
            } else {
              bp_options = bp->GetOptions();
            }

            if (bp_options) {
              StreamString id_str;
              BreakpointID::GetCanonicalReference(&id_str,
                                                  cur_bp_id.GetBreakpointID(),
                                                  cur_bp_id.GetLocationID());
              const Baton *baton = bp_options->GetBaton();
              if (baton) {
                result.GetOutputStream().Printf("Breakpoint %s:\n",
                                                id_str.GetData());
                result.GetOutputStream().IndentMore();
                baton->GetDescription(&result.GetOutputStream(),
                                      eDescriptionLevelFull);
                result.GetOutputStream().IndentLess();
              } else {
                result.AppendMessageWithFormat(
                    "Breakpoint %s does not have an associated command.\n",
                    id_str.GetData());
              }
            }
            result.SetStatus(eReturnStatusSuccessFinishResult);
          } else {
            result.AppendErrorWithFormat("Invalid breakpoint ID: %u.\n",
                                         cur_bp_id.GetBreakpointID());
            result.SetStatus(eReturnStatusFailed);
          }
        }
      }
    }

    return result.Succeeded();
  }
};

//-------------------------------------------------------------------------
// CommandObjectBreakpointCommand
//-------------------------------------------------------------------------

CommandObjectBreakpointCommand::CommandObjectBreakpointCommand(
    CommandInterpreter &interpreter)
    : CommandObjectMultiword(
          interpreter, "command", "Commands for adding, removing and listing "
                                  "LLDB commands executed when a breakpoint is "
                                  "hit.",
          "command <sub-command> [<sub-command-options>] <breakpoint-id>") {
  CommandObjectSP add_command_object(
      new CommandObjectBreakpointCommandAdd(interpreter));
  CommandObjectSP delete_command_object(
      new CommandObjectBreakpointCommandDelete(interpreter));
  CommandObjectSP list_command_object(
      new CommandObjectBreakpointCommandList(interpreter));

  add_command_object->SetCommandName("breakpoint command add");
  delete_command_object->SetCommandName("breakpoint command delete");
  list_command_object->SetCommandName("breakpoint command list");

  LoadSubCommand("add", add_command_object);
  LoadSubCommand("delete", delete_command_object);
  LoadSubCommand("list", list_command_object);
}

CommandObjectBreakpointCommand::~CommandObjectBreakpointCommand() = default;