This file is indexed.

/usr/lib/ruby/1.8/debug.rb is in libruby1.8 1.8.7.352-2ubuntu1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
# Copyright (C) 2000  Network Applied Communication Laboratory, Inc.
# Copyright (C) 2000  Information-technology Promotion Agency, Japan
# Copyright (C) 2000-2003  NAKAMURA, Hiroshi  <nahi@ruby-lang.org>

if $SAFE > 0
  STDERR.print "-r debug.rb is not available in safe mode\n"
  exit 1
end

require 'tracer'
require 'pp'

class Tracer
  def Tracer.trace_func(*vars)
    Single.trace_func(*vars)
  end
end

SCRIPT_LINES__ = {} unless defined? SCRIPT_LINES__

class DEBUGGER__
class Mutex
  def initialize
    @locker = nil
    @waiting = []
    @locked = false;
  end

  def locked?
    @locked
  end

  def lock
    return if Thread.critical
    return if @locker == Thread.current
    while (Thread.critical = true; @locked)
      @waiting.push Thread.current
      Thread.stop
    end
    @locked = true
    @locker = Thread.current
    Thread.critical = false
    self
  end

  def unlock
    return if Thread.critical
    return unless @locked
    unless @locker == Thread.current
      raise RuntimeError, "unlocked by other"
    end
    Thread.critical = true
    t = @waiting.shift
    @locked = false
    @locker = nil
    Thread.critical = false
    t.run if t
    self
  end
end
MUTEX = Mutex.new

class Context
  DEBUG_LAST_CMD = []

  begin
    require 'readline'
    def readline(prompt, hist)
      Readline::readline(prompt, hist)
    end
  rescue LoadError
    def readline(prompt, hist)
      STDOUT.print prompt
      STDOUT.flush
      line = STDIN.gets
      exit unless line
      line.chomp!
      line
    end
    USE_READLINE = false
  end

  def initialize
    if Thread.current == Thread.main
      @stop_next = 1
    else
      @stop_next = 0
    end
    @last_file = nil
    @file = nil
    @line = nil
    @no_step = nil
    @frames = []
    @finish_pos = 0
    @trace = false
    @catch = "StandardError"
    @suspend_next = false
  end

  def stop_next(n=1)
    @stop_next = n
  end

  def set_suspend
    @suspend_next = true
  end

  def clear_suspend
    @suspend_next = false
  end

  def suspend_all
    DEBUGGER__.suspend
  end

  def resume_all
    DEBUGGER__.resume
  end

  def check_suspend
    return if Thread.critical
    while (Thread.critical = true; @suspend_next)
      DEBUGGER__.waiting.push Thread.current
      @suspend_next = false
      Thread.stop
    end
    Thread.critical = false
  end

  def trace?
    @trace
  end

  def set_trace(arg)
    @trace = arg
  end

  def stdout
    DEBUGGER__.stdout
  end

  def break_points
    DEBUGGER__.break_points
  end

  def display
    DEBUGGER__.display
  end

  def context(th)
    DEBUGGER__.context(th)
  end

  def set_trace_all(arg)
    DEBUGGER__.set_trace(arg)
  end

  def set_last_thread(th)
    DEBUGGER__.set_last_thread(th)
  end

  def debug_eval(str, binding)
    begin
      val = eval(str, binding)
    rescue StandardError, ScriptError => e
      at = eval("caller(1)", binding)
      stdout.printf "%s:%s\n", at.shift, e.to_s.sub(/\(eval\):1:(in `.*?':)?/, '')
      for i in at
	stdout.printf "\tfrom %s\n", i
      end
      throw :debug_error
    end
  end

  def debug_silent_eval(str, binding)
    begin
      eval(str, binding)
    rescue StandardError, ScriptError
      nil
    end
  end

  def var_list(ary, binding)
    ary.sort!
    for v in ary
      stdout.printf "  %s => %s\n", v, eval(v, binding).inspect
    end
  end

  def debug_variable_info(input, binding)
    case input
    when /^\s*g(?:lobal)?\s*$/
      var_list(global_variables, binding)

    when /^\s*l(?:ocal)?\s*$/
      var_list(eval("local_variables", binding), binding)

    when /^\s*i(?:nstance)?\s+/
      obj = debug_eval($', binding)
      var_list(obj.instance_variables, obj.instance_eval{binding()})

    when /^\s*c(?:onst(?:ant)?)?\s+/
      obj = debug_eval($', binding)
      unless obj.kind_of? Module
	stdout.print "Should be Class/Module: ", $', "\n"
      else
	var_list(obj.constants, obj.module_eval{binding()})
      end
    end
  end

  def debug_method_info(input, binding)
    case input
    when /^i(:?nstance)?\s+/
      obj = debug_eval($', binding)

      len = 0
      for v in obj.methods.sort
	len += v.size + 1
	if len > 70
	  len = v.size + 1
	  stdout.print "\n"
	end
	stdout.print v, " "
      end
      stdout.print "\n"

    else
      obj = debug_eval(input, binding)
      unless obj.kind_of? Module
	stdout.print "Should be Class/Module: ", input, "\n"
      else
	len = 0
	for v in obj.instance_methods(false).sort
	  len += v.size + 1
	  if len > 70
	    len = v.size + 1
	    stdout.print "\n"
	  end
	  stdout.print v, " "
	end
	stdout.print "\n"
      end
    end
  end

  def thnum
    num = DEBUGGER__.instance_eval{@thread_list[Thread.current]}
    unless num
      DEBUGGER__.make_thread_list
      num = DEBUGGER__.instance_eval{@thread_list[Thread.current]}
    end
    num
  end

  def debug_command(file, line, id, binding)
    MUTEX.lock
    unless defined?($debugger_restart) and $debugger_restart
      callcc{|c| $debugger_restart = c} 
    end
    set_last_thread(Thread.current)
    frame_pos = 0
    binding_file = file
    binding_line = line
    previous_line = nil
    if ENV['EMACS']
      stdout.printf "\032\032%s:%d:\n", binding_file, binding_line
    else
      stdout.printf "%s:%d:%s", binding_file, binding_line,
	line_at(binding_file, binding_line)
    end
    @frames[0] = [binding, file, line, id]
    display_expressions(binding)
    prompt = true
    while prompt and input = readline("(rdb:%d) "%thnum(), true)
      catch(:debug_error) do
	if input == ""
          next unless DEBUG_LAST_CMD[0]
	  input = DEBUG_LAST_CMD[0]
	  stdout.print input, "\n"
	else
	  DEBUG_LAST_CMD[0] = input
	end

	case input
	when /^\s*tr(?:ace)?(?:\s+(on|off))?(?:\s+(all))?$/
          if defined?( $2 )
            if $1 == 'on'
              set_trace_all true
            else
              set_trace_all false
            end
          elsif defined?( $1 )
            if $1 == 'on'
              set_trace true
            else
              set_trace false
            end
          end
          if trace?
            stdout.print "Trace on.\n"
          else
            stdout.print "Trace off.\n"
          end

	when /^\s*b(?:reak)?\s+(?:(.+):)?([^.:]+)$/
	  pos = $2
          if $1
            klass = debug_silent_eval($1, binding)
            file = $1
          end
	  if pos =~ /^\d+$/
	    pname = pos
	    pos = pos.to_i
	  else
	    pname = pos = pos.intern.id2name
	  end
	  break_points.push [true, 0, klass || file, pos]
	  stdout.printf "Set breakpoint %d at %s:%s\n", break_points.size, klass || file, pname

	when /^\s*b(?:reak)?\s+(.+)[#.]([^.:]+)$/
	  pos = $2.intern.id2name
	  klass = debug_eval($1, binding)
	  break_points.push [true, 0, klass, pos]
	  stdout.printf "Set breakpoint %d at %s.%s\n", break_points.size, klass, pos

	when /^\s*wat(?:ch)?\s+(.+)$/
	  exp = $1
	  break_points.push [true, 1, exp]
	  stdout.printf "Set watchpoint %d:%s\n", break_points.size, exp

	when /^\s*b(?:reak)?$/
	  if break_points.find{|b| b[1] == 0}
	    n = 1
	    stdout.print "Breakpoints:\n"
	    for b in break_points
	      if b[0] and b[1] == 0
		stdout.printf "  %d %s:%s\n", n, b[2], b[3] 
	      end
	      n += 1
	    end
	  end
	  if break_points.find{|b| b[1] == 1}
	    n = 1
	    stdout.print "\n"
	    stdout.print "Watchpoints:\n"
	    for b in break_points
	      if b[0] and b[1] == 1
		stdout.printf "  %d %s\n", n, b[2]
	      end
	      n += 1
	    end
	  end
	  if break_points.size == 0
	    stdout.print "No breakpoints\n"
	  else
	    stdout.print "\n"
	  end

	when /^\s*del(?:ete)?(?:\s+(\d+))?$/
	  pos = $1
	  unless pos
	    input = readline("Clear all breakpoints? (y/n) ", false)
	    if input == "y"
	      for b in break_points
		b[0] = false
	      end
	    end
	  else
	    pos = pos.to_i
	    if break_points[pos-1]
	      break_points[pos-1][0] = false
	    else
	      stdout.printf "Breakpoint %d is not defined\n", pos
	    end
	  end

	when /^\s*disp(?:lay)?\s+(.+)$/
	  exp = $1
	  display.push [true, exp]
	  stdout.printf "%d: ", display.size
	  display_expression(exp, binding)

	when /^\s*disp(?:lay)?$/
	  display_expressions(binding)

	when /^\s*undisp(?:lay)?(?:\s+(\d+))?$/
	  pos = $1
	  unless pos
	    input = readline("Clear all expressions? (y/n) ", false)
	    if input == "y"
	      for d in display
		d[0] = false
	      end
	    end
	  else
	    pos = pos.to_i
	    if display[pos-1]
	      display[pos-1][0] = false
	    else
	      stdout.printf "Display expression %d is not defined\n", pos
	    end
	  end

	when /^\s*c(?:ont)?$/
	  prompt = false

	when /^\s*s(?:tep)?(?:\s+(\d+))?$/
	  if $1
	    lev = $1.to_i
	  else
	    lev = 1
	  end
	  @stop_next = lev
	  prompt = false

	when /^\s*n(?:ext)?(?:\s+(\d+))?$/
	  if $1
	    lev = $1.to_i
	  else
	    lev = 1
	  end
	  @stop_next = lev
	  @no_step = @frames.size - frame_pos
	  prompt = false

	when /^\s*w(?:here)?$/, /^\s*f(?:rame)?$/
	  display_frames(frame_pos)

	when /^\s*l(?:ist)?(?:\s+(.+))?$/
	  if not $1
	    b = previous_line ? previous_line + 10 : binding_line - 5
	    e = b + 9
	  elsif $1 == '-'
	    b = previous_line ? previous_line - 10 : binding_line - 5
	    e = b + 9
	  else
	    b, e = $1.split(/[-,]/)
	    if e
	      b = b.to_i
	      e = e.to_i
	    else
	      b = b.to_i - 5
	      e = b + 9
	    end
	  end
	  previous_line = b
	  display_list(b, e, binding_file, binding_line)

	when /^\s*up(?:\s+(\d+))?$/
	  previous_line = nil
	  if $1
	    lev = $1.to_i
	  else
	    lev = 1
	  end
	  frame_pos += lev
	  if frame_pos >= @frames.size
	    frame_pos = @frames.size - 1
	    stdout.print "At toplevel\n"
	  end
	  binding, binding_file, binding_line = @frames[frame_pos]
	  stdout.print format_frame(frame_pos)

	when /^\s*down(?:\s+(\d+))?$/
	  previous_line = nil
	  if $1
	    lev = $1.to_i
	  else
	    lev = 1
	  end
	  frame_pos -= lev
	  if frame_pos < 0
	    frame_pos = 0
	    stdout.print "At stack bottom\n"
	  end
	  binding, binding_file, binding_line = @frames[frame_pos]
	  stdout.print format_frame(frame_pos)

	when /^\s*fin(?:ish)?$/
	  if frame_pos == @frames.size
	    stdout.print "\"finish\" not meaningful in the outermost frame.\n"
	  else
	    @finish_pos = @frames.size - frame_pos
	    frame_pos = 0
	    prompt = false
	  end

	when /^\s*cat(?:ch)?(?:\s+(.+))?$/
	  if $1
	    excn = $1
	    if excn == 'off'
	      @catch = nil
	      stdout.print "Clear catchpoint.\n"
	    else
	      @catch = excn
	      stdout.printf "Set catchpoint %s.\n", @catch
	    end
	  else
	    if @catch
	      stdout.printf "Catchpoint %s.\n", @catch
	    else
	      stdout.print "No catchpoint.\n"
	    end
	  end

	when /^\s*q(?:uit)?$/
	  input = readline("Really quit? (y/n) ", false)
	  if input == "y"
	    exit!	# exit -> exit!: No graceful way to stop threads...
	  end

	when /^\s*v(?:ar)?\s+/
	  debug_variable_info($', binding)

	when /^\s*m(?:ethod)?\s+/
	  debug_method_info($', binding)

	when /^\s*th(?:read)?\s+/
	  if DEBUGGER__.debug_thread_info($', binding) == :cont
	    prompt = false
	  end

	when /^\s*pp\s+/
	  PP.pp(debug_eval($', binding), stdout)

	when /^\s*p\s+/
	  stdout.printf "%s\n", debug_eval($', binding).inspect

	when /^\s*r(?:estart)?$/
          $debugger_restart.call

	when /^\s*h(?:elp)?$/
	  debug_print_help()

	else
	  v = debug_eval(input, binding)
	  stdout.printf "%s\n", v.inspect
	end
      end
    end
    MUTEX.unlock
    resume_all
  end

  def debug_print_help
    stdout.print <<EOHELP
Debugger help v.-0.002b
Commands
  b[reak] [file:|class:]<line|method>
  b[reak] [class.]<line|method>
                             set breakpoint to some position
  wat[ch] <expression>       set watchpoint to some expression
  cat[ch] (<exception>|off)  set catchpoint to an exception
  b[reak]                    list breakpoints
  cat[ch]                    show catchpoint
  del[ete][ nnn]             delete some or all breakpoints
  disp[lay] <expression>     add expression into display expression list
  undisp[lay][ nnn]          delete one particular or all display expressions
  c[ont]                     run until program ends or hit breakpoint
  s[tep][ nnn]               step (into methods) one line or till line nnn
  n[ext][ nnn]               go over one line or till line nnn
  w[here]                    display frames
  f[rame]                    alias for where
  l[ist][ (-|nn-mm)]         list program, - lists backwards
                             nn-mm lists given lines
  up[ nn]                    move to higher frame
  down[ nn]                  move to lower frame
  fin[ish]                   return to outer frame
  tr[ace] (on|off)           set trace mode of current thread
  tr[ace] (on|off) all       set trace mode of all threads
  q[uit]                     exit from debugger
  v[ar] g[lobal]             show global variables
  v[ar] l[ocal]              show local variables
  v[ar] i[nstance] <object>  show instance variables of object
  v[ar] c[onst] <object>     show constants of object
  m[ethod] i[nstance] <obj>  show methods of object
  m[ethod] <class|module>    show instance methods of class or module
  th[read] l[ist]            list all threads
  th[read] c[ur[rent]]       show current thread
  th[read] [sw[itch]] <nnn>  switch thread context to nnn
  th[read] stop <nnn>        stop thread nnn
  th[read] resume <nnn>      resume thread nnn
  p expression               evaluate expression and print its value
  h[elp]                     print this help
  <everything else>          evaluate
EOHELP
  end

  def display_expressions(binding)
    n = 1
    for d in display
      if d[0]
	stdout.printf "%d: ", n
	display_expression(d[1], binding)
      end
      n += 1
    end
  end

  def display_expression(exp, binding)
    stdout.printf "%s = %s\n", exp, debug_silent_eval(exp, binding).to_s
  end

  def frame_set_pos(file, line)
    if @frames[0]
      @frames[0][1] = file
      @frames[0][2] = line
    end
  end

  def display_frames(pos)
    0.upto(@frames.size - 1) do |n|
      if n == pos
	stdout.print "--> "
      else
	stdout.print "    "
      end
      stdout.print format_frame(n)
    end
  end

  def format_frame(pos)
    bind, file, line, id = @frames[pos]
    sprintf "#%d %s:%s%s\n", pos + 1, file, line,
      (id ? ":in `#{id.id2name}'" : "")
  end

  def display_list(b, e, file, line)
    stdout.printf "[%d, %d] in %s\n", b, e, file
    if lines = SCRIPT_LINES__[file] and lines != true
      n = 0
      b.upto(e) do |n|
	if n > 0 && lines[n-1]
	  if n == line
	    stdout.printf "=> %d  %s\n", n, lines[n-1].chomp
	  else
	    stdout.printf "   %d  %s\n", n, lines[n-1].chomp
	  end
	end
      end
    else
      stdout.printf "No sourcefile available for %s\n", file
    end
  end

  def line_at(file, line)
    lines = SCRIPT_LINES__[file]
    if lines
      return "\n" if lines == true
      line = lines[line-1]
      return "\n" unless line
      return line
    end
    return "\n"
  end

  def debug_funcname(id)
    if id.nil?
      "toplevel"
    else
      id.id2name
    end
  end

  def check_break_points(file, klass, pos, binding, id)
    return false if break_points.empty?
    n = 1
    for b in break_points
      if b[0]		# valid
	if b[1] == 0	# breakpoint
	  if (b[2] == file and b[3] == pos) or
	      (klass and b[2] == klass and b[3] == pos)
	    stdout.printf "Breakpoint %d, %s at %s:%s\n", n, debug_funcname(id), file, pos
	    return true
	  end
	elsif b[1] == 1	# watchpoint
	  if debug_silent_eval(b[2], binding)
	    stdout.printf "Watchpoint %d, %s at %s:%s\n", n, debug_funcname(id), file, pos
	    return true
	  end
	end
      end
      n += 1
    end
    return false
  end

  def excn_handle(file, line, id, binding)
    if $!.class <= SystemExit
      set_trace_func nil
      exit
    end

    if @catch and ($!.class.ancestors.find { |e| e.to_s == @catch })
      stdout.printf "%s:%d: `%s' (%s)\n", file, line, $!, $!.class
      fs = @frames.size
      tb = caller(0)[-fs..-1]
      if tb
	for i in tb
	  stdout.printf "\tfrom %s\n", i
	end
      end
      suspend_all
      debug_command(file, line, id, binding)
    end
  end

  def trace_func(event, file, line, id, binding, klass)
    Tracer.trace_func(event, file, line, id, binding, klass) if trace?
    context(Thread.current).check_suspend
    @file = file
    @line = line
    case event
    when 'line'
      frame_set_pos(file, line)
      if !@no_step or @frames.size == @no_step
	@stop_next -= 1
	@stop_next = -1 if @stop_next < 0
      elsif @frames.size < @no_step
	@stop_next = 0		# break here before leaving...
      else
	# nothing to do. skipped.
      end
      if @stop_next == 0 or check_break_points(file, nil, line, binding, id)
	@no_step = nil
	suspend_all
	debug_command(file, line, id, binding)
      end

    when 'call'
      @frames.unshift [binding, file, line, id]
      if check_break_points(file, klass, id.id2name, binding, id)
	suspend_all
	debug_command(file, line, id, binding)
      end

    when 'c-call'
      frame_set_pos(file, line)

    when 'class'
      @frames.unshift [binding, file, line, id]

    when 'return', 'end'
      if @frames.size == @finish_pos
	@stop_next = 1
	@finish_pos = 0
      end
      @frames.shift

    when 'end'
      @frames.shift

    when 'raise' 
      excn_handle(file, line, id, binding)

    end
    @last_file = file
  end
end

trap("INT") { DEBUGGER__.interrupt }
@last_thread = Thread::main
@max_thread = 1
@thread_list = {Thread::main => 1}
@break_points = []
@display = []
@waiting = []
@stdout = STDOUT

class << DEBUGGER__
  def stdout
    @stdout
  end

  def stdout=(s)
    @stdout = s
  end

  def display
    @display
  end

  def break_points
    @break_points
  end

  def waiting
    @waiting
  end

  def set_trace( arg )
    saved_crit = Thread.critical
    Thread.critical = true
    make_thread_list
    for th, in @thread_list
      context(th).set_trace arg
    end
    Thread.critical = saved_crit
    arg
  end

  def set_last_thread(th)
    @last_thread = th
  end

  def suspend
    saved_crit = Thread.critical
    Thread.critical = true
    make_thread_list
    for th, in @thread_list
      next if th == Thread.current
      context(th).set_suspend
    end
    Thread.critical = saved_crit
    # Schedule other threads to suspend as soon as possible.
    Thread.pass unless Thread.critical
  end

  def resume
    saved_crit = Thread.critical
    Thread.critical = true
    make_thread_list
    for th, in @thread_list
      next if th == Thread.current
      context(th).clear_suspend
    end
    waiting.each do |th|
      th.run
    end
    waiting.clear
    Thread.critical = saved_crit
    # Schedule other threads to restart as soon as possible.
    Thread.pass
  end

  def context(thread=Thread.current)
    c = thread[:__debugger_data__]
    unless c
      thread[:__debugger_data__] = c = Context.new
    end
    c
  end

  def interrupt
    context(@last_thread).stop_next
  end

  def get_thread(num)
    th = @thread_list.index(num)
    unless th
      @stdout.print "No thread ##{num}\n"
      throw :debug_error
    end
    th
  end

  def thread_list(num)
    th = get_thread(num)
    if th == Thread.current
      @stdout.print "+"
    else
      @stdout.print " "
    end
    @stdout.printf "%d ", num
    @stdout.print th.inspect, "\t"
    file = context(th).instance_eval{@file}
    if file
      @stdout.print file,":",context(th).instance_eval{@line}
    end
    @stdout.print "\n"
  end

  def thread_list_all
    for th in @thread_list.values.sort
      thread_list(th)
    end
  end

  def make_thread_list
    hash = {}
    for th in Thread::list
      if @thread_list.key? th
	hash[th] = @thread_list[th]
      else
	@max_thread += 1
	hash[th] = @max_thread
      end
    end
    @thread_list = hash
  end

  def debug_thread_info(input, binding)
    case input
    when /^l(?:ist)?/
      make_thread_list
      thread_list_all

    when /^c(?:ur(?:rent)?)?$/
      make_thread_list
      thread_list(@thread_list[Thread.current])

    when /^(?:sw(?:itch)?\s+)?(\d+)/
      make_thread_list
      th = get_thread($1.to_i)
      if th == Thread.current
	@stdout.print "It's the current thread.\n"
      else
	thread_list(@thread_list[th])
	context(th).stop_next
	th.run
	return :cont
      end

    when /^stop\s+(\d+)/
      make_thread_list
      th = get_thread($1.to_i)
      if th == Thread.current
	@stdout.print "It's the current thread.\n"
      elsif th.stop?
	@stdout.print "Already stopped.\n"
      else
	thread_list(@thread_list[th])
	context(th).suspend 
      end

    when /^resume\s+(\d+)/
      make_thread_list
      th = get_thread($1.to_i)
      if th == Thread.current
	@stdout.print "It's the current thread.\n"
      elsif !th.stop?
	@stdout.print "Already running."
      else
	thread_list(@thread_list[th])
	th.run
      end
    end
  end
end

stdout.printf "Debug.rb\n"
stdout.printf "Emacs support available.\n\n"
set_trace_func proc { |event, file, line, id, binding, klass, *rest|
  DEBUGGER__.context.trace_func event, file, line, id, binding, klass
}
end