module Byebug

Summary¶ ↑

This is a singleton class allows controlling byebug. Use it to start/stop byebug, set/remove breakpoints, etc.

Main Container for all of Byebug's code

Namespace for all of byebug's code

Constants

INIT_FILE: Configuration file used for startup commands. Default value is .byebugrc
PORT: Port number used for remote debugging
RESTART_FILE: Default file where commands are saved
VERSION

Attributes

actual_control_port[R]

actual_port[RW]

The actual port that the server is started at

wait_connection[RW]

If in remote mode, wait for the remote connection

handler[RW]

Main debugger's processor

mode[RW]

Running mode of the debugger. Can be either:

:attached => Attached to a running program through the `byebug` method.
:standalone => Started through `bin/byebug` script.

printer[RW]

Main debugger's printer

Public Class Methods

add_catchpoint(exception) → exception click to toggle source

Adds a new exception to the catchpoints array.

static VALUE
Add_catchpoint(VALUE self, VALUE value)
{
  UNUSED(self);

  if (TYPE(value) != T_STRING)
    rb_raise(rb_eTypeError, "value of a catchpoint must be String");

  rb_hash_aset(catchpoints, rb_str_dup(value), INT2FIX(0));
  return value;
}

attach() click to toggle source

Enters byebug right before (or right after if before is false) return events occur. Before entering byebug the init script is read.

# File lib/byebug/attacher.rb, line 9
def self.attach
  unless started?
    self.mode = :attached

    start
    run_init_script
  end

  current_context.step_out(2, true)
end

breakpoints → array click to toggle source

Returns an array of breakpoints.

static VALUE
Breakpoints(VALUE self)
{
  UNUSED(self);

  if (NIL_P(breakpoints))
    breakpoints = rb_ary_new();

  return breakpoints;
}

catchpoints → array click to toggle source

Returns an array of catchpoints.

static VALUE
Catchpoints(VALUE self)
{
  UNUSED(self);

  return catchpoints;
}

contexts → array click to toggle source

Returns an array of all contexts.

static VALUE
Contexts(VALUE self)
{
  volatile VALUE list;
  volatile VALUE new_list;
  VALUE context;
  threads_table_t *t_tbl;
  debug_context_t *dc;
  int i;

  UNUSED(self);

  check_started();

  new_list = rb_ary_new();
  list = rb_funcall(rb_cThread, rb_intern("list"), 0);

  for (i = 0; i < RARRAY_LENINT(list); i++)
  {
    VALUE thread = rb_ary_entry(list, i);

    thread_context_lookup(thread, &context);
    rb_ary_push(new_list, context);
  }

  Data_Get_Struct(threads, threads_table_t, t_tbl);
  st_clear(t_tbl->tbl);

  for (i = 0; i < RARRAY_LENINT(new_list); i++)
  {
    context = rb_ary_entry(new_list, i);
    Data_Get_Struct(context, debug_context_t, dc);
    st_insert(t_tbl->tbl, dc->thread, context);
  }

  return new_list;
}

current_context → context click to toggle source

Returns the current context.

<i>Note:</i> Byebug.current_context.thread == Thread.current

static VALUE
Current_context(VALUE self)
{
  VALUE context;

  UNUSED(self);

  check_started();

  thread_context_lookup(rb_thread_current(), &context);

  return context;
}

debug_load(file, stop = false) → nil click to toggle source

Same as Kernel#load but resets current context's frames. stop parameter forces byebug to stop at the first line of code in file

static VALUE
Debug_load(int argc, VALUE * argv, VALUE self)
{
  VALUE file, stop, context;
  debug_context_t *dc;
  VALUE status = Qnil;
  int state = 0;

  UNUSED(self);

  if (rb_scan_args(argc, argv, "11", &file, &stop) == 1)
    stop = Qfalse;

  Start(self);

  context = Current_context(self);
  Data_Get_Struct(context, debug_context_t, dc);

  dc->calced_stack_size = 1;

  if (RTEST(stop))
    dc->steps = 1;

  rb_load_protect(file, 0, &state);
  if (0 != state)
  {
    status = rb_errinfo();
    reset_stepping_stop_points(dc);
  }

  return status;
}

handle_post_mortem() click to toggle source

Saves information about the unhandled exception and gives a byebug prompt back to the user before program termination.

# File lib/byebug/settings/post_mortem.rb, line 30
def self.handle_post_mortem
  return unless Byebug.raised_exception

  context = Byebug.raised_exception.__bb_context
  file = Byebug.raised_exception.__bb_file
  line = Byebug.raised_exception.__bb_line

  Byebug.handler.at_line(context, file, line)
end

interrupt() click to toggle source

Interrupts the current thread

# File lib/byebug/remote.rb, line 18
def interrupt
  current_context.interrupt
end

parse_host_and_port(host_port_spec) click to toggle source

# File lib/byebug/remote.rb, line 91
def parse_host_and_port(host_port_spec)
  location = host_port_spec.split(':')
  location[1] ? [location[0], location[1].to_i] : ['localhost', location[0]]
end

post_mortem = bool click to toggle source

Sets post-moterm flag.

static VALUE
Set_post_mortem(VALUE self, VALUE value)
{
  UNUSED(self);

  post_mortem = RTEST(value) ? Qtrue : Qfalse;
  return value;
}

post_mortem? → bool click to toggle source

Returns true if post-mortem debugging is enabled.

static VALUE
Post_mortem(VALUE self)
{
  UNUSED(self);

  return post_mortem;
}

raised_exception → exception click to toggle source

Returns raised exception when in post_mortem mode.

static VALUE
Raised_exception(VALUE self)
{
  UNUSED(self);

  return raised_exception;
}

start → bool click to toggle source

The return value is the value of !Byebug.started? before issuing the start; That is, true is returned, unless byebug was previously started.

static VALUE
Start(VALUE self)
{
  if (IS_STARTED)
    return Qfalse;

  catchpoints = rb_hash_new();

  threads = create_threads_table();

  register_tracepoints(self);

  return Qtrue;
}

start_client(host = 'localhost', port = PORT) click to toggle source

Connects to the remote byebug

# File lib/byebug/remote.rb, line 66
def start_client(host = 'localhost', port = PORT)
  handler.interface = LocalInterface.new
  puts 'Connecting to byebug server...'
  socket = TCPSocket.new(host, port)
  puts 'Connected.'

  catch(:exit) do
    while (line = socket.gets)
      case line
      when /^PROMPT (.*)$/
        input = handler.interface.read_command(Regexp.last_match[1])
        throw :exit unless input
        socket.puts input
      when /^CONFIRM (.*)$/
        input = handler.interface.confirm(Regexp.last_match[1])
        throw :exit unless input
        socket.puts input
      else
        puts line
      end
    end
  end
  socket.close
end

start_control(host = nil, ctrl_port = PORT + 1) click to toggle source

# File lib/byebug/remote.rb, line 50
def start_control(host = nil, ctrl_port = PORT + 1)
  return @actual_control_port if @control_thread
  server = TCPServer.new(host, ctrl_port)
  @actual_control_port = server.addr[1]
  @control_thread = DebugThread.new do
    while (session = server.accept)
      handler.interface = RemoteInterface.new(session)
      ControlCommandProcessor.new(handler.interface).process_commands
    end
  end
  @actual_control_port
end

start_server(host = nil, port = PORT) { || ... } click to toggle source

Starts a remote byebug

# File lib/byebug/remote.rb, line 25
def start_server(host = nil, port = PORT)
  return if @thread

  handler.interface = nil
  start

  start_control(host, port == 0 ? 0 : port + 1)

  yield if block_given?

  mutex = Mutex.new
  proceed = ConditionVariable.new

  server = TCPServer.new(host, port)
  self.actual_port = server.addr[1]
  @thread = DebugThread.new do
    while (session = server.accept)
      handler.interface = RemoteInterface.new(session)
      mutex.synchronize { proceed.signal } if wait_connection
    end
  end

  mutex.synchronize { proceed.wait(mutex) } if wait_connection
end

started? → bool click to toggle source

Returns true byebug is started.

static VALUE
Started(VALUE self)
{
  UNUSED(self);

  return IS_STARTED;
}

stop → bool click to toggle source

This method disables byebug. It returns true if byebug was already disabled, otherwise it returns false.

static VALUE
Stop(VALUE self)
{
  UNUSED(self);

  if (IS_STARTED)
  {
    clear_tracepoints(self);

    breakpoints = Qnil;
    catchpoints = Qnil;
    threads = Qnil;

    return Qfalse;
  }

  return Qtrue;
}

thread_context(thread) → context click to toggle source

Returns context of the thread passed as an argument.

static VALUE
Thread_context(VALUE self, VALUE thread)
{
  VALUE context;

  UNUSED(self);

  check_started();

  thread_context_lookup(thread, &context);

  return context;
}

tracing = bool click to toggle source

Sets the global tracing flag.

static VALUE
Set_tracing(VALUE self, VALUE value)
{
  UNUSED(self);

  tracing = RTEST(value) ? Qtrue : Qfalse;
  return value;
}

tracing? → bool click to toggle source

Returns true if global tracing is enabled.

static VALUE
Tracing(VALUE self)
{
  UNUSED(self);

  return tracing;
}

verbose = bool click to toggle source

Enable verbose output of every TracePoint API events, useful for debugging byebug.

static VALUE
Set_verbose(VALUE self, VALUE value)
{
  UNUSED(self);

  verbose = RTEST(value) ? Qtrue : Qfalse;
  return value;
}

verbose? → bool click to toggle source

Returns true if verbose output of TracePoint API events is enabled.

static VALUE
Verbose(VALUE self)
{
  UNUSED(self);

  return verbose;
}

Public Instance Methods

run_init_script() click to toggle source

Runs normal byebug initialization scripts.

Reads and executes the commands from init file (if any) in the current working directory. This is only done if the current directory is different from your home directory. Thus, you can have more than one init file, one generic in your home directory, and another, specific to the program you are debugging, in the directory where you invoke byebug.

# File lib/byebug/core.rb, line 50
def run_init_script
  home_rc = File.expand_path(File.join(ENV['HOME'].to_s, INIT_FILE))
  run_script(home_rc) if File.exist?(home_rc)

  cwd_rc = File.expand_path(File.join('.', INIT_FILE))
  run_script(cwd_rc) if File.exist?(cwd_rc) && cwd_rc != home_rc
end

Private Instance Methods

run_script(file, verbose = false) click to toggle source

Runs a script file

# File lib/byebug/core.rb, line 63
def run_script(file, verbose = false)
  interface = ScriptInterface.new(file, verbose)
  processor = ControlCommandProcessor.new(interface)
  processor.process_commands
end