summaryrefslogtreecommitdiff
path: root/test/ruby/test_optimization.rb
blob: d4a1fdbcea738907e2f34f94f081405606cc56a7 (plain)
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
# frozen_string_literal: false
require 'test/unit'
require 'objspace'

class TestRubyOptimization < Test::Unit::TestCase
  def assert_redefine_method(klass, method, code, msg = nil)
    assert_separately([], "#{<<-"begin;"}\n#{<<~"end;"}")
    begin;
      class #{klass}
        undef #{method}
        def #{method}(*args)
          args[0]
        end
      end
      #{code}
    end;
  end

  def disasm(name)
    RubyVM::InstructionSequence.of(method(name)).disasm
  end

  def test_fixnum_plus
    assert_equal 21, 10 + 11
    assert_redefine_method('Integer', '+', 'assert_equal 11, 10 + 11')
  end

  def test_fixnum_minus
    assert_equal 5, 8 - 3
    assert_redefine_method('Integer', '-', 'assert_equal 3, 8 - 3')
  end

  def test_fixnum_mul
    assert_equal 15, 3 * 5
    assert_redefine_method('Integer', '*', 'assert_equal 5, 3 * 5')
  end

  def test_fixnum_div
    assert_equal 3, 15 / 5
    assert_redefine_method('Integer', '/', 'assert_equal 5, 15 / 5')
  end

  def test_fixnum_mod
    assert_equal 1, 8 % 7
    assert_redefine_method('Integer', '%', 'assert_equal 7, 8 % 7')
  end

  def test_fixnum_lt
    assert_equal true, 1 < 2
    assert_redefine_method('Integer', '<', 'assert_equal 2, 1 < 2')
  end

  def test_fixnum_le
    assert_equal true, 1 <= 2
    assert_redefine_method('Integer', '<=', 'assert_equal 2, 1 <= 2')
  end

  def test_fixnum_gt
    assert_equal false, 1 > 2
    assert_redefine_method('Integer', '>', 'assert_equal 2, 1 > 2')
  end

  def test_fixnum_ge
    assert_equal false, 1 >= 2
    assert_redefine_method('Integer', '>=', 'assert_equal 2, 1 >= 2')
  end

  def test_float_plus
    assert_equal 4.0, 2.0 + 2.0
    assert_redefine_method('Float', '+', 'assert_equal 2.0, 2.0 + 2.0')
  end

  def test_float_minus
    assert_equal 4.0, 2.0 + 2.0
    assert_redefine_method('Float', '+', 'assert_equal 2.0, 2.0 + 2.0')
  end

  def test_float_mul
    assert_equal 29.25, 4.5 * 6.5
    assert_redefine_method('Float', '*', 'assert_equal 6.5, 4.5 * 6.5')
  end

  def test_float_div
    assert_in_delta 0.63063063063063063, 4.2 / 6.66
    assert_redefine_method('Float', '/', 'assert_equal 6.66, 4.2 / 6.66', "[Bug #9238]")
  end

  def test_float_lt
    assert_equal true, 1.1 < 2.2
    assert_redefine_method('Float', '<', 'assert_equal 2.2, 1.1 < 2.2')
  end

  def test_float_le
    assert_equal true, 1.1 <= 2.2
    assert_redefine_method('Float', '<=', 'assert_equal 2.2, 1.1 <= 2.2')
  end

  def test_float_gt
    assert_equal false, 1.1 > 2.2
    assert_redefine_method('Float', '>', 'assert_equal 2.2, 1.1 > 2.2')
  end

  def test_float_ge
    assert_equal false, 1.1 >= 2.2
    assert_redefine_method('Float', '>=', 'assert_equal 2.2, 1.1 >= 2.2')
  end

  def test_string_length
    assert_equal 6, "string".length
    assert_redefine_method('String', 'length', 'assert_nil "string".length')
  end

  def test_string_size
    assert_equal 6, "string".size
    assert_redefine_method('String', 'size', 'assert_nil "string".size')
  end

  def test_string_empty?
    assert_equal true, "".empty?
    assert_equal false, "string".empty?
    assert_redefine_method('String', 'empty?', 'assert_nil "string".empty?')
  end

  def test_string_plus
    assert_equal "", "" + ""
    assert_equal "x", "x" + ""
    assert_equal "x", "" + "x"
    assert_equal "ab", "a" + "b"
    assert_redefine_method('String', '+', 'assert_equal "b", "a" + "b"')
  end

  def test_string_succ
    assert_equal 'b', 'a'.succ
    assert_equal 'B', 'A'.succ
  end

  def test_string_format
    assert_equal '2', '%d' % 2
    assert_redefine_method('String', '%', 'assert_equal 2, "%d" % 2')
  end

  def test_string_freeze
    assert_equal "foo", "foo".freeze
    assert_equal "foo".freeze.object_id, "foo".freeze.object_id
    assert_redefine_method('String', 'freeze', 'assert_nil "foo".freeze')
  end

  def test_string_uminus
    assert_same "foo".freeze, -"foo"
    assert_redefine_method('String', '-@', 'assert_nil(-"foo")')
  end

  def test_string_freeze_saves_memory
    n = 16384
    data = '.'.freeze
    r, w = IO.pipe
    w.write data

    s = r.readpartial(n, '')
    assert_operator ObjectSpace.memsize_of(s), :>=, n,
      'IO buffer NOT resized prematurely because will likely be reused'

    s.freeze
    assert_equal ObjectSpace.memsize_of(data), ObjectSpace.memsize_of(s),
      'buffer resized on freeze since it cannot be written to again'
  ensure
    r.close if r
    w.close if w
  end

  def test_string_eq_neq
    %w(== !=).each do |m|
      assert_redefine_method('String', m, <<-end)
        assert_equal :b, ("a" #{m} "b").to_sym
        b = 'b'
        assert_equal :b, ("a" #{m} b).to_sym
        assert_equal :b, (b #{m} "b").to_sym
      end
    end
  end

  def test_string_ltlt
    assert_equal "", "" << ""
    assert_equal "x", "x" << ""
    assert_equal "x", "" << "x"
    assert_equal "ab", "a" << "b"
    assert_redefine_method('String', '<<', 'assert_equal "b", "a" << "b"')
  end

  def test_array_plus
    assert_equal [1,2], [1]+[2]
    assert_redefine_method('Array', '+', 'assert_equal [2], [1]+[2]')
  end

  def test_array_minus
    assert_equal [2], [1,2] - [1]
    assert_redefine_method('Array', '-', 'assert_equal [1], [1,2]-[1]')
  end

  def test_array_length
    assert_equal 0, [].length
    assert_equal 3, [1,2,3].length
    assert_redefine_method('Array', 'length', 'assert_nil([].length); assert_nil([1,2,3].length)')
  end

  def test_array_empty?
    assert_equal true, [].empty?
    assert_equal false, [1,2,3].empty?
    assert_redefine_method('Array', 'empty?', 'assert_nil([].empty?); assert_nil([1,2,3].empty?)')
  end

  def test_hash_length
    assert_equal 0, {}.length
    assert_equal 1, {1=>1}.length
    assert_redefine_method('Hash', 'length', 'assert_nil({}.length); assert_nil({1=>1}.length)')
  end

  def test_hash_empty?
    assert_equal true, {}.empty?
    assert_equal false, {1=>1}.empty?
    assert_redefine_method('Hash', 'empty?', 'assert_nil({}.empty?); assert_nil({1=>1}.empty?)')
  end

  def test_hash_aref_with
    h = { "foo" => 1 }
    assert_equal 1, h["foo"]
    assert_redefine_method('Hash', '[]', "#{<<-"begin;"}\n#{<<~"end;"}")
    begin;
      h = { "foo" => 1 }
      assert_equal "foo", h["foo"]
    end;
  end

  def test_hash_aset_with
    h = {}
    assert_equal 1, h["foo"] = 1
    assert_redefine_method('Hash', '[]=', "#{<<-"begin;"}\n#{<<~"end;"}")
    begin;
      h = {}
      assert_equal 1, h["foo"] = 1, "assignment always returns value set"
      assert_nil h["foo"]
    end;
  end

  class MyObj
    def ==(other)
      true
    end
  end

  def test_eq
    assert_equal true, nil == nil
    assert_equal true, 1 == 1
    assert_equal true, 'string' == 'string'
    assert_equal true, 1 == MyObj.new
    assert_equal false, nil == MyObj.new
    assert_equal true, MyObj.new == 1
    assert_equal true, MyObj.new == nil
  end

  def self.tailcall(klass, src, file = nil, path = nil, line = nil, tailcall: true)
    unless file
      loc, = caller_locations(1, 1)
      file = loc.path
      line ||= loc.lineno
    end
    RubyVM::InstructionSequence.new("proc {|_|_.class_eval {#{src}}}",
                                    file, (path || file), line,
                                    tailcall_optimization: tailcall,
                                    trace_instruction: false)
      .eval[klass]
  end

  def tailcall(*args)
    self.class.tailcall(singleton_class, *args)
  end

  def test_tailcall
    bug4082 = '[ruby-core:33289]'

    tailcall("#{<<-"begin;"}\n#{<<~"end;"}")
    begin;
      def fact_helper(n, res)
        if n == 1
          res
        else
          fact_helper(n - 1, n * res)
        end
      end
      def fact(n)
        fact_helper(n, 1)
      end
    end;
    assert_equal(9131, fact(3000).to_s.size, message(bug4082) {disasm(:fact_helper)})
  end

  def test_tailcall_with_block
    bug6901 = '[ruby-dev:46065]'

    tailcall("#{<<-"begin;"}\n#{<<~"end;"}")
    begin;
      def identity(val)
        val
      end

      def delay
        -> {
          identity(yield)
        }
      end
    end;
    assert_equal(123, delay { 123 }.call, message(bug6901) {disasm(:delay)})
  end

  def just_yield
    yield
  end

  def test_tailcall_inhibited_by_block
    tailcall("#{<<-"begin;"}\n#{<<~"end;"}")
    begin;
      def yield_result
        just_yield {:ok}
      end
    end;
    assert_equal(:ok, yield_result, message {disasm(:yield_result)})
  end

  def do_raise
    raise "should be rescued"
  end

  def errinfo
    $!
  end

  def test_tailcall_inhibited_by_rescue
    bug12082 = '[ruby-core:73871] [Bug #12082]'

    tailcall("#{<<-"begin;"}\n#{<<~"end;"}")
    begin;
      def to_be_rescued
        return do_raise
        1 + 2
      rescue
        errinfo
      end
    end;
    result = assert_nothing_raised(RuntimeError, message(bug12082) {disasm(:to_be_rescued)}) {
      to_be_rescued
    }
    assert_instance_of(RuntimeError, result, bug12082)
    assert_equal("should be rescued", result.message, bug12082)
  end

  def test_tailcall_symbol_block_arg
    bug12565 = '[ruby-core:46065]'
    tailcall("#{<<-"begin;"}\n#{<<~"end;"}")
    begin;
      def apply_one_and_two(&block)
        yield(1, 2)
      end

      def add_one_and_two
        apply_one_and_two(&:+)
      end
    end;
    assert_equal(3, add_one_and_two,
                 message(bug12565) {disasm(:add_one_and_two)})
  end

  def test_tailcall_interrupted_by_sigint
    bug12576 = 'ruby-core:76327'
    script = "#{<<-"begin;"}\n#{<<~'end;'}"
    begin;
      RubyVM::InstructionSequence.compile_option = {
        :tailcall_optimization => true,
        :trace_instruction => false
      }

      eval "#{<<~"begin;"}\n#{<<~'end;1'}"
      begin;
        def foo
          foo
        end
        puts("start")
        STDOUT.flush
        foo
      end;1
    end;
    status, _err = EnvUtil.invoke_ruby([], "", true, true, {}) {
      |in_p, out_p, err_p, pid|
      in_p.write(script)
      in_p.close
      out_p.gets
      sig = :INT
      begin
        Process.kill(sig, pid)
        Timeout.timeout(1) do
          *, stat = Process.wait2(pid)
          [stat, err_p.read]
        end
      rescue Timeout::Error
        if sig == :INT
          sig = :KILL
          retry
        else
          raise
        end
      end
    }
    assert_not_equal("SEGV", Signal.signame(status.termsig || 0), bug12576)
  end unless /mswin|mingw/ =~ RUBY_PLATFORM

  def test_tailcall_condition_block
    bug = '[ruby-core:78015] [Bug #12905]'

    src = "#{<<-"begin;"}\n#{<<~"end;"}"
    begin;
      def run(current, final)
        if current < final
          run(current+1, final)
        else
          nil
        end
      end
    end;

    obj = Object.new
    self.class.tailcall(obj.singleton_class, src, tailcall: false)
    e = assert_raise(SystemStackError) {
      obj.run(1, Float::INFINITY)
    }
    level = e.backtrace_locations.size
    obj = Object.new
    self.class.tailcall(obj.singleton_class, src, tailcall: true)
    level *= 2
    mesg = message {"#{bug}: #{$!.backtrace_locations.size} / #{level} stack levels"}
    assert_nothing_raised(SystemStackError, mesg) {
      obj.run(1, level)
    }
  end

  class Bug10557
    def [](_)
      block_given?
    end

    def []=(_, _)
      block_given?
    end
  end

  def test_block_given_aset_aref
    bug10557 = '[ruby-core:66595]'
    assert_equal(true, Bug10557.new.[](nil){}, bug10557)
    assert_equal(true, Bug10557.new.[](0){}, bug10557)
    assert_equal(true, Bug10557.new.[](false){}, bug10557)
    assert_equal(true, Bug10557.new.[](''){}, bug10557)
    assert_equal(true, Bug10557.new.[]=(nil, 1){}, bug10557)
    assert_equal(true, Bug10557.new.[]=(0, 1){}, bug10557)
    assert_equal(true, Bug10557.new.[]=(false, 1){}, bug10557)
    assert_equal(true, Bug10557.new.[]=('', 1){}, bug10557)
  end

  def test_string_freeze_block
    assert_separately([], "#{<<-"begin;"}\n#{<<~"end;"}")
    begin;
      class String
        undef freeze
        def freeze
          block_given?
        end
      end
      assert_equal(true, "block".freeze {})
      assert_equal(false, "block".freeze)
    end;
  end

  def test_opt_case_dispatch
    code = "#{<<-"begin;"}\n#{<<~"end;"}"
    begin;
      case foo
      when "foo" then :foo
      when true then true
      when false then false
      when :sym then :sym
      when 6 then :fix
      when nil then nil
      when 0.1 then :float
      when 0xffffffffffffffff then :big
      else
        :nomatch
      end
    end;
    check = {
      'foo' => :foo,
      true => true,
      false => false,
      :sym => :sym,
      6 => :fix,
      nil => nil,
      0.1 => :float,
      0xffffffffffffffff => :big,
    }
    iseq = RubyVM::InstructionSequence.compile(code)
    assert_match %r{\bopt_case_dispatch\b}, iseq.disasm
    check.each do |foo, expect|
      assert_equal expect, eval("foo = #{foo.inspect}\n#{code}")
    end
    assert_equal :nomatch, eval("foo = :blah\n#{code}")
    check.each do |foo, _|
      klass = foo.class.to_s
      assert_separately([], "#{<<~"begin;"}\n#{<<~"end;"}")
      begin;
        class #{klass}
          undef ===
          def ===(*args)
            false
          end
        end
        foo = #{foo.inspect}
        ret = #{code}
        assert_equal :nomatch, ret, foo.inspect
      end;
    end
  end

  def test_eqq
    [ nil, true, false, 0.1, :sym, 'str', 0xffffffffffffffff ].each do |v|
      k = v.class.to_s
      assert_redefine_method(k, '===', "assert_equal(#{v.inspect} === 0, 0)")
    end
  end

  def test_opt_case_dispatch_inf
    inf = 1.0/0.0
    result = case inf
             when 1 then 1
             when 0 then 0
             else
               inf.to_i rescue nil
             end
    assert_nil result, '[ruby-dev:49423] [Bug #11804]'
  end

  def test_nil_safe_conditional_assign
    bug11816 = '[ruby-core:74993] [Bug #11816]'
    assert_ruby_status([], 'nil&.foo &&= false', bug11816)
  end

  def test_peephole_string_literal_range
    code = "#{<<~"begin;"}\n#{<<~"end;"}"
    begin;
      case ver
      when "2.0.0".."2.3.2" then :foo
      when "1.8.0"..."1.8.8" then :bar
      end
    end;
    [ true, false ].each do |opt|
      iseq = RubyVM::InstructionSequence.compile(code,
                                                 frozen_string_literal: opt)
      insn = iseq.disasm
      assert_match %r{putobject\s+#{Regexp.quote('"1.8.0"..."1.8.8"')}}, insn
      assert_match %r{putobject\s+#{Regexp.quote('"2.0.0".."2.3.2"')}}, insn
      assert_no_match(/putstring/, insn)
      assert_no_match(/newrange/, insn)
    end
  end

  def test_peephole_dstr
    code = "#{<<~'begin;'}\n#{<<~'end;'}"
    begin;
      exp = -'a'
      z = 'a'
      [exp, -"#{z}"]
    end;
    [ false, true ].each do |fsl|
      iseq = RubyVM::InstructionSequence.compile(code,
                                                 frozen_string_literal: fsl)
      assert_same(*iseq.eval,
                  "[ruby-core:85542] [Bug #14475] fsl: #{fsl}")
    end
  end

  def test_branch_condition_backquote
    bug = '[ruby-core:80740] [Bug #13444] redefined backquote should be called'
    class << self
      def `(s)
        @q = s
        @r
      end
    end

    @q = nil
    @r = nil
    assert_equal("bar", ("bar" unless `foo`), bug)
    assert_equal("foo", @q, bug)

    @q = nil
    @r = true
    assert_equal("bar", ("bar" if `foo`), bug)
    assert_equal("foo", @q, bug)

    @q = nil
    @r = "z"
    assert_equal("bar", ("bar" if `foo#{@r}`))
    assert_equal("fooz", @q, bug)
  end

  def test_branch_condition_def
    bug = '[ruby-core:80740] [Bug #13444] method should be defined'
    c = Class.new do
      raise "bug" unless def t;:ok;end
    end
    assert_nothing_raised(NoMethodError, bug) do
      assert_equal(:ok, c.new.t)
    end
  end

  def test_branch_condition_defs
    bug = '[ruby-core:80740] [Bug #13444] singleton method should be defined'
    raise "bug" unless def self.t;:ok;end
    assert_nothing_raised(NameError, bug) do
      assert_equal(:ok, t)
    end
  end

  def test_retry_label_in_unreachable_chunk
    bug = '[ruby-core:81272] [Bug #13578]'
    assert_valid_syntax("#{<<-"begin;"}\n#{<<-"end;"}", bug)
    begin;
      def t; if false; case 42; when s {}; end; end; end
    end;
  end

  def bptest_yield &b
    yield
  end

  def bptest_yield_pass &b
    bptest_yield(&b)
  end

  def bptest_bp_value &b
    b
  end

  def bptest_bp_pass_bp_value &b
    bptest_bp_value(&b)
  end

  def bptest_binding &b
    binding
  end

  def bptest_set &b
    b = Proc.new{2}
  end

  def test_block_parameter
    assert_equal(1, bptest_yield{1})
    assert_equal(1, bptest_yield_pass{1})
    assert_equal(1, send(:bptest_yield){1})

    assert_equal(Proc, bptest_bp_value{}.class)
    assert_equal nil, bptest_bp_value
    assert_equal(Proc, bptest_bp_pass_bp_value{}.class)
    assert_equal nil, bptest_bp_pass_bp_value

    assert_equal Proc, bptest_binding{}.local_variable_get(:b).class

    assert_equal 2, bptest_set{1}.call
  end

  def test_block_parameter_should_not_create_objects
    assert_separately [], <<-END
      #
      def foo &b
      end
      h1 = {}; h2 = {}
      ObjectSpace.count_objects(h1) # reharsal
      ObjectSpace.count_objects(h1)
      foo{}
      ObjectSpace.count_objects(h2)

      assert_equal 0, h2[:TOTAL] - h1[:TOTAL]
    END
  end

  def test_block_parameter_should_restore_safe_level
    assert_separately [], <<-END
      #
      def foo &b
        $SAFE = 1
        b.call
      end
      assert_equal 1, foo{$SAFE}
    END
  end

  def test_peephole_optimization_without_trace
    assert_separately [], <<-END
      RubyVM::InstructionSequence.compile_option = {trace_instruction: false}
      eval "def foo; 1.times{|(a), &b| nil && a}; end"
    END
  end

  def test_clear_unreachable_keyword_args
    assert_separately [], <<-END, timeout: 30
      script =  <<-EOS
        if true
        else
          foo(k1:1)
        end
      EOS
      GC.stress = true
      30.times{
        RubyVM::InstructionSequence.compile(script)
      }
    END
  end

  def test_callinfo_unreachable_path
    assert_separately([], "#{<<~"begin;"}\n#{<<~'end;'}")
    begin;
      iseq = RubyVM::InstructionSequence.compile("if false; foo(bar: :baz); else :ok end")
      bin = iseq.to_binary
      iseq = RubyVM::InstructionSequence.load_from_binary(bin)
      assert_instance_of(RubyVM::InstructionSequence, iseq)
      assert_equal(:ok, iseq.eval)
    end;
  end

  def test_side_effect_in_popped_splat
    bug = '[ruby-core:84340] [Bug #14201]'
    eval("{**(bug = nil; {})};42")
    assert_nil(bug)

    bug = '[ruby-core:85486] [Bug #14459]'
    h = {}
    assert_equal(bug, eval('{ok: 42, **h}; bug'))
    assert_equal(:ok, eval('{ok: bug = :ok, **h}; bug'))
  end

  def test_overwritten_blockparam
    obj = Object.new
    def obj.a(&block)
      block = 1
      return :ok if block
      :ng
    end
    assert_equal(:ok, obj.a())
  end

  def test_blockparam_in_rescue
    obj = Object.new
    def obj.foo(&b)
      raise
    rescue
      b.call
    end
    result = nil
    assert_equal(42, obj.foo {result = 42})
    assert_equal(42, result)
  end

  def test_unconditional_branch_to_leave_block
    assert_valid_syntax("#{<<~"begin;"}\n#{<<~'end;'}")
    begin;
      tap {true || tap {}}
    end;
  end

  def test_jump_elimination_with_optimized_out_block
    x = Object.new
    def x.bug(obj)
      if obj || obj
        obj = obj
      else
        raise "[ruby-core:87830] [Bug #14897]"
      end
      obj
    end
    assert_equal(:ok, x.bug(:ok))
  end
end