megenginelite-sys 1.8.2

A safe megenginelite wrapper in Rust
Documentation
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
#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import argparse
import collections
import textwrap
import os
import hashlib
import struct

class member_defs:
    """contain classes to define members of an opr param"""

    Dtype = collections.namedtuple('Dtype', ['cname', 'pycvt', 'pyfmt',
                                             'cppjson', 'cname_attr'])
    Dtype.__new__.__defaults__ = ('', )
    uint32 = Dtype('uint32_t', 'int', 'I', 'NumberInt')
    uint64 = Dtype('uint64_t', 'int', 'Q', 'NumberInt',
                   'alignas(sizeof(uint64_t)) ')
    int32 = Dtype('int32_t', 'int', 'i', 'NumberInt')
    float32 = Dtype('float', 'float', 'f', 'Number')
    float64 = Dtype('double', 'float', 'd', 'Number')
    dtype = Dtype('DTypeEnum', '_as_dtype_num', 'I', 'Number')
    bool = Dtype('bool', 'bool', '?', 'Bool')

    class Base:
        pass


    class Doc:
        """wrap an identifier to associate document

        note: if the doc starts with a linebreak, it would not be reforamtted.
        """
        __slots__ = ['id', 'doc']

        def __init__(self, id_, doc):
            assert isinstance(id_, str) and isinstance(doc, str), (id_, doc)
            self.id = id_
            self.doc = doc

        @property
        def no_reformat(self):
            """whether reformat is disallowed for this doc string"""
            return self.doc.startswith('\n')

        @property
        def raw_lines(self):
            """the doc lines when ``no_format`` is true"""
            ret = self.doc.split('\n')
            assert not ret[0]
            return ret[1:]

        @classmethod
        def make(cls, v):
            """make doc object from str or doc"""
            if isinstance(v, cls):
                return v
            assert isinstance(v, str)
            return cls(v, '')

        def __str__(self):
            return self.id

        def __eq__(self, rhs):
            if isinstance(rhs, str):
                return self.id == rhs
            return (isinstance(rhs, Doc) and
                    (self.id, self.doc) == (rhs.id, rhs.doc))


    class Enum(Base):
        """define an enum; the result would contain both an enum class def and its
        corresponding data field

        :param default:
            for normal enum class: index of default member value
            for bit combined class: tuple of index of default member value

            For example, following representations of the default value for bit
            combined class are all equivalent:
                Enum(members=('a', 'b', 'c'), default=('a', 'b'), ...)
                Enum(members=('a', 'b', 'c'), default=(0, 1), ...)
                Enum(members=('a', 'b', 'c'), default=(1 << 0) | (1 << 1), ...)

        :attr name_field: name of the data field of this enum in the param
            struct
        :attr member_alias:
            for normal enum class: list of (member, alias) pairs
            for bit combined class: list of (tuple of members, alias) paris
        """
        __slots__ = ['name', 'name_field', 'members', 'default',
                     'member_alias', 'combined']

        all_enums = {}
        """(param_name, name) => enum"""

        def __init__(self, param_name, name, name_field, members, default,
                member_alias, combined = False):
            name = member_defs.Doc.make(name)
            assert name.id[0].isupper()
            members = tuple(map(member_defs.Doc.make, members))
            self.name = name
            self.combined = combined
            self.name_field = self.get_name_field(name.id, name_field)
            self.members = members
            self.default = self.normalize_enum_value(default)

            self.all_enums[(param_name, name.id)] = self

            assert isinstance(member_alias, list)
            self.member_alias = member_alias

        @classmethod
        def get_name_field(cls, name, name_field):
            if name_field is None:
                name_field = name[0].lower() + name[1:]
            assert isinstance(name_field, str)
            return name_field

        def normalize_enum_value(self, value):
            def normalize(v):
                if isinstance(v, str):
                    for idx, m in enumerate(self.members):
                        m = str(m).split(' ')[0].split('=')[0]
                        if v == m :
                            return idx
                    raise ValueError(
                        "enum member '{}' does not exist.".format(v))
                assert isinstance(v, int)
                return v
            if self.combined:
                if isinstance(value, int):
                    value = self.decompose_combined_enum(value)
                assert isinstance(value, tuple)
                value = tuple(normalize(i) for i in value)
                return value
            else:
                return normalize(value)

        @staticmethod
        def decompose_combined_enum(v):
            """Integer => tuple of the indexes of the enum members"""
            assert isinstance(v, int)
            idx = 0
            members = []
            while v > 0:
                if v & 1:
                    members.append(idx)
                idx += 1
                v >>= 1
            return tuple(members)

        def compose_combined_enum(self, v):
            """tuple of members => Integer"""
            assert self.combined and isinstance(v, tuple)
            norm_v = self.normalize_enum_value(v)
            return sum(1 << i for i in norm_v)

    class Field(Base):
        """define a normal data field"""
        __slots__ = ['name', 'dtype', 'default']

        def __init__(self, name, dtype, default):
            assert isinstance(dtype, member_defs.Dtype)
            self.name = member_defs.Doc.make(name)
            self.dtype = dtype
            self.default = default

    class Const(Base):
        """define a const data field"""
        __slots__ = ['name', 'dtype', 'default']

        def __init__(self, name, dtype, default):
            assert isinstance(dtype, member_defs.Dtype)
            self.name = member_defs.Doc.make(name)
            self.dtype = dtype
            self.default = default

    class EnumAlias(Base):
        """alias of enum type from another param"""
        __slots__ = ['name', 'name_field', 'src_class', 'src_name', 'default']

        def __init__(self, name, name_field, src_class, src_name, default):
            self.name = name
            self.name_field = member_defs.Enum.get_name_field(name, name_field)
            self.src_class = src_class
            if src_name is None:
                src_name = name
            self.src_name = src_name
            self.default = default
            # TODO: remove this assertion if needed; adding mock param_defs in
            # current testing framework is too complicated, and currently we
            # only allow aliasing of normal enum
            assert not self.src_enum.combined

        @property
        def src_enum(self):
            """source Enum class"""
            return member_defs.Enum.all_enums[(self.src_class, self.src_name)]

        def get_default(self):
            """get default index; fallback to src index if default is not
            set"""
            if self.default is None:
                return self.src_enum.default
            return self.src_enum.normalize_enum_value(self.default)


class ParamDef:
    """"""
    __all_tags = set()
    all_param_defs = []

    __slots__ = ['name', 'members', 'tag', 'is_legacy']

    def __init__(self, name, doc='', *, version=0, is_legacy=False):
        self.members = []
        self.all_param_defs.append(self)
        h = hashlib.sha256(name.encode('utf-8'))
        if version:
            h.update(struct.pack('<I', version))
        if is_legacy:
            name += 'V{}'.format(version)
        self.name = member_defs.Doc(name, doc)
        self.tag = int(h.hexdigest()[:8], 16)
        self.is_legacy = is_legacy
        if self.tag < 1024:
            self.tag += 1024
        assert self.tag not in self.__all_tags, (
            'tag hash confliction: name={} tag={}'.format(name, self.tag))
        self.__all_tags.add(self.tag)

    def add_fields(self, dtype, *names_defaults):
        assert isinstance(dtype, str)
        dtype = getattr(member_defs, dtype)
        assert len(names_defaults) % 2 == 0
        for i, j in zip(names_defaults[::2], names_defaults[1::2]):
            self.members.append(member_defs.Field(i, dtype, j))
        return self

    def add_enum(self, name, *members, default=0, name_field=None,
                 member_alias=[]):
        self.members.append(member_defs.Enum(
            self.name.id, name, name_field, members, default, member_alias))
        return self

    def add_bit_combination_enum(self, name, *members, default=tuple(),
                 name_field=None, member_alias=[]):
        self.members.append(member_defs.Enum(
            self.name.id, name, name_field, members, default, member_alias, True))
        return self

    def add_enum_alias(self, name, src_class, src_name=None, name_field=None,
                       default=None):
        self.members.append(member_defs.EnumAlias(
            name, name_field, src_class, src_name, default))
        return self

    def add_const(self, dtype, *names_defaults):
        assert isinstance(dtype, str)
        dtype = getattr(member_defs, dtype)
        assert len(names_defaults) % 2 == 0
        for i, j in zip(names_defaults[::2], names_defaults[1::2]):
            self.members.append(member_defs.Const(i, dtype, j))
        return self


class WriterBase:
    """base class for output file writer"""

    _fout = None
    _input_hash = None

    def __call__(self, fout):
        self._fout = fout

    def set_input_hash(self, h):
        self._input_hash = h
        return self

    def _get_header(self):
        return 'generated by {} for {}'.format(
            os.path.basename(__file__),
            self._input_hash
        )

    def _process(self, defs):
        dispatch = {
            member_defs.Enum: self._on_member_enum,
            member_defs.EnumAlias: self._on_member_enum_alias,
            member_defs.Field: self._on_member_field,
            member_defs.Const: self._on_const_field
        }
        for i in defs:
            assert isinstance(i, ParamDef)
            self._on_param_begin(i)
            for j in i.members:
                dispatch[type(j)](j)
            self._on_param_end(i)

    def _on_param_begin(self, p):
        """:type p: :class:`.ParamDef`"""

    def _on_param_end(self, p):
        """:type p: :class:`.ParamDef`"""

    def _on_member_enum(self, e):
        """:type p: :class:`.Enum`"""

    def _on_member_enum_alias(self, e):
        """:type p: :class:`.EnumAlias`"""

    def _on_member_field(self, f):
        """:type p: :class:`.Field`"""

    def _on_const_field(self, f):
        """:type p: :class:`.Const`"""


class IndentWriterBase(WriterBase):
    _cur_indent = ''

    def _indent(self):
        self._cur_indent += ' ' * 4

    def _unindent(self):
        self._cur_indent = self._cur_indent[:-4]

    def _write(self, content, *fmt, indent=0):
        if indent < 0:
            self._unindent()

        self._fout.write(self._cur_indent)
        if fmt:
            content = content % fmt
        self._fout.write(content)
        self._fout.write('\n')

        if indent > 0:
            self._indent()


class PyWriter(IndentWriterBase):
    FieldDef = collections.namedtuple(
        'FieldDef', ['name', 'cvt', 'fmt', 'default', 'type', 'doc'])
    # see _on_param_end() for the use of those fields

    _cur_param_name = None
    _cur_fields = None
    _cur_struct_fmt = None

    _enum_member2num = None

    def __init__(self, for_imperative=False):
        self._imperative = for_imperative

    def __call__(self, fout, defs):
        super().__call__(fout)
        self._enum_member2num = []
        self._write('# %s', self._get_header())
        self._write('import struct')
        self._write('from . import enum36 as enum')
        self._write(
            'class _ParamDefBase:\n'
            '   def serialize(self):\n'
            '       tag = struct.pack("I", type(self).TAG)\n'
            '       pdata = [getattr(self, i) for i in self.__slots__]\n'
            '       for idx, v in enumerate(pdata):\n'
            '           if isinstance(v, _EnumBase):\n'
            '               pdata[idx] = _enum_member2num[id(v)]\n'
            '           elif isinstance(v, _BitCombinedEnumBase):\n'
            '               pdata[idx] = v._value_\n'
            '       return tag + self._packer.pack(*pdata)\n'
            '\n'
        )
        # it's hard to mix custom implemention into enum, just do copy-paste instead
        classbody = (
            '   @classmethod\n'
            '   def __normalize(cls, val):\n'
            '       if isinstance(val, str):\n'
            '           if not hasattr(cls, "__member_upper_dict__"):\n'
            '               cls.__member_upper_dict__ = {k.upper(): v\n'
            '                   for k, v in cls.__members__.items()}\n'
            '           val = cls.__member_upper_dict__.get(val.upper(),val)\n'
            '       return val\n'
            '   @classmethod\n'
            '   def convert(cls, val):\n'
            '       val = cls.__normalize(val)\n'
            '       if isinstance(val, cls):\n'
            '           return val\n'
            '       return cls(val)\n'
            '   @classmethod\n'
            '   def _missing_(cls, value):\n'
            '       vnorm = cls.__normalize(value)\n'
            '       if vnorm is not value:\n'
            '           return cls(vnorm)\n'
            '       return super()._missing_(value)\n'
            '\n'
        )
        self._write(
            'class _EnumBase(enum.Enum):\n' + classbody
        )
        self._write(
            'class _BitCombinedEnumBase(enum.Flag):\n' + classbody
        )
        if not self._imperative:
            self._write(
                'def _as_dtype_num(dtype):\n'
                '    import megbrain.mgb as m\n'
                '    return m._get_dtype_num(dtype)\n'
                '\n'
            )

            self._write(
                'def _as_serialized_dtype(dtype):\n'
                '    import megbrain.mgb as m\n'
                '    return m._get_serialized_dtype(dtype)\n'
                '\n'
            )
        else:
            self._write(
                'def _as_dtype_num(dtype):\n'
                '    import megengine.core._imperative_rt.utils as m\n'
                '    return m._get_dtype_num(dtype)\n'
                '\n'
            )

            self._write(
                'def _as_serialized_dtype(dtype):\n'
                '    import megengine.core._imperative_rt.utils as m\n'
                '    return m._get_serialized_dtype(dtype)\n'
                '\n'
            )

        self._process(defs)
        self._write(
            '''
class SerializedDType(_ParamDefBase):
    TAG = FakeSerializedDType.TAG
    __slots__ = ['dtype']
    class IdentityPacker:
        def pack(self, *args):
            assert all([isinstance(x, bytes) for x in args])
            return b''.join(args)
    _packer = IdentityPacker()
    def __init__(self, dtype):
        """
        :type dtype: :class:`np.dtype` compatible
        """
        self.dtype = _as_serialized_dtype(dtype)
'''
        )
        self._write('_enum_member2num = {\n  %s}',
                    ',\n  '.join(self._enum_member2num))

    def _write_doc(self, doc):
        assert isinstance(doc, member_defs.Doc)
        if not doc.doc:
            return
        if doc.no_reformat:
            self._write('"""')
            for i in doc.raw_lines:
                self._write(i)
            self._write('"""')
            return

        doc = doc.doc.replace('\n', ' ')
        textwidth = 80 - len(self._cur_indent)
        self._write('"""')
        for i in textwrap.wrap(doc, textwidth):
            self._write(i)
        self._write('"""')


    def _on_param_begin(self, p):
        self._cur_param_name = str(p.name)
        self._cur_fields = []
        self._cur_enum_names = []
        self._write('class %s(_ParamDefBase):', p.name, indent=1)
        self._write_doc(p.name)
        self._write('TAG = %d', p.tag)

    def _on_param_end(self, p):
        # gen slots and packer
        self._write('__slots__ = [%s]', ', '.join(
            map('"{.name}"'.format, self._cur_fields)))
        struct_fmt = ''.join(i.fmt for i in self._cur_fields)
        if not struct_fmt:
            struct_fmt = 'x'
        else:
            # add padding at end
            max_t = max(struct_fmt, key=struct.calcsize)
            struct_fmt += '0{}'.format(max_t)
        self._write('_packer = struct.Struct("%s")', struct_fmt)

        # gen __init__ signature
        self._write('def __init__(%s):',
                    ', '.join(['self'] +
                              list('{}={}'.format(i.name, i.default)
                                   for i in self._cur_fields)),
                    indent=1)
        # gen __init__ doc
        self._write('"""')
        for i in self._cur_fields:
            self._write(':type {}: :class:`.{}`'.format(i.name, i.type))
            if i.doc:
                self._write(':param {}: {}'.format(i.name, i.doc))
        self._write('"""')

        # gen cvt in __init__
        for i in self._cur_fields:
            self._write('self.%s = %s', i.name, i.cvt)

        self._unindent()
        self._unindent()
        self._write('')

    def _on_member_enum(self, e):
        qualname = '{}.{}'.format(self._cur_param_name, e.name)

        if e.combined:
            self._write('class %s(_BitCombinedEnumBase):', e.name, indent=1)
        else:
            self._write('class %s(_EnumBase):', e.name, indent=1)

        self._write_doc(e.name)

        for emem in e.members:
            if e.combined:
                self._write('%s', emem)
                self._write_doc(emem)
            else:
                v = str(emem).split(' ')[0].split('=')[0]
                n = int(str(emem).split('=')[1])
                self._write('%s = "%s"', v, v)
                self._write_doc(emem)
                self._enum_member2num.append('id({}.{}):{}'.format(
                    qualname, v, n))

        for emem, emem_alias in e.member_alias:
            em_a = emem_alias.split(' ')[0].split('=')[0]
            if e.combined:
                self._write('%s = %s', em_a, e.compose_combined_enum(emem))
            else:
                em = str(emem).split(' ')[0].split('=')[0]
                self._write('%s = %s', em_a, em)

        self._unindent()
        self._write('')

        if e.combined:
            default = e.compose_combined_enum(e.default)
        else:
            default = "'{}'".format(str(e.members[e.default]).split(' ')[0].split('=')[0])

        self._cur_fields.append(self.FieldDef(
            name=e.name_field,
            cvt='{}.convert({})'.format(qualname, e.name_field),
            fmt='I',
            default=default,
            type=qualname,
            doc=None))

    def _on_member_enum_alias(self, e):
        self._write('%s = %s.%s', e.name, e.src_class, e.src_name)
        s = e.src_enum
        qualname = '{}.{}'.format(e.src_class, e.src_name)

        if s.combined:
            default = s.compose_combined_enum(e.get_default())
        else:
            default = "'{}'".format(str(s.members[e.get_default()]).split(' ')[0].split('=')[0])
        self._cur_fields.append(self.FieldDef(
            name=e.name_field,
            cvt='{}.convert({})'.format(qualname, e.name_field),
            fmt='I',
            default=default,
            type=qualname,
            doc=None))

    def _get_py_default(self, cppdefault):
        if not isinstance(cppdefault, str):
            return cppdefault

        d = cppdefault
        if d.endswith('f'): # 1.f
            return d[:-1]
        if d.endswith('ull'):
            return d[:-3]
        if d == 'false':
            return 'False'
        if d == 'true':
            return 'True'
        if d.startswith('DTypeEnum::'):
            return '"{}"'.format(d.split(':')[2].lower())
        return d

    def _on_member_field(self, f):
        d = self._get_py_default(f.default)

        self._cur_fields.append(self.FieldDef(
            name=f.name,
            cvt='{}({})'.format(f.dtype.pycvt, f.name),
            fmt=f.dtype.pyfmt,
            default=d,
            type=f.dtype.pycvt,
            doc=f.name.doc
        ))

    def _on_const_field(self, f):
        d = self._get_py_default(f.default)
        self._write_doc(f.name)
        self._write('%s = %s', f.name, d)



class CPPWriter(IndentWriterBase):
    _param_namespace = 'param'

    _ctor_args = None
    """list of (text in func param, var name); func param name must be var name
    appended by an underscore"""
    _non_static_members = None

    def __call__(self, fout, defs):
        super().__call__(fout)
        self._write('// %s', self._get_header())
        self._write('#pragma once')
        self._write('#include "megdnn/dtype.h"')
        self._write('#include <stdint.h>')
        if self._param_namespace == 'param':
            self._write('#include <string.h>')
        self._write('namespace megdnn {')
        self._write('namespace %s {', self._param_namespace)
        self._process(defs)
        self._write('} // namespace megdnn')
        self._write('} // namespace %s', self._param_namespace)
        self._write('// vim: syntax=cpp.doxygen')

    def _write_doc(self, doc):
        assert isinstance(doc, member_defs.Doc)
        if not doc.doc:
            return

        if doc.no_reformat:
            self._write('/*')
            for i in doc.raw_lines:
                self._write('* ' + i)
            self._write('*/')
            return

        doc = doc.doc.replace('\n', ' ')
        textwidth = 80 - len(self._cur_indent) - 4
        if len(doc) <= textwidth:
            self._write('//! ' + doc)
            return

        self._write('/*!')
        for i in textwrap.wrap(doc, textwidth):
            self._write(' * ' + i)
        self._write(' */')

    def _on_param_begin(self, p):
        self._write_doc(p.name)
        self._write('struct %s {', p.name, indent=1)
        self._write('static MEGDNN_CONSTEXPR uint32_t TAG = %du;', p.tag)
        self._ctor_args = []
        self._non_static_members = []

    def _add_ctor_args(self, typename, default, varname):
        self._ctor_args.append((
            '{} {}_={}'.format(typename, varname, default),
            varname))

    def _on_param_end(self, p):
        '''
        MegDNN param structures are not packed and we need to initialize the structure
        paddings to zero or it would break MegBrain hash system. We do memset(0) in default
        ctor and use a trick, wrapping non-static members in a anonymous union which would
        copy the object representation in its default copy/move ctor, for copy/move ctor.
        > The implicitly-defined copy/move constructor for a non-union class X performs
        > a memberwise copy/move of its bases and members. [class.copy.ctor 14]
        > The implicitly-defined copy/move constructor for a union X copies the object
        > representation (6.9) of X. [class.copy.ctor 15]
        '''
        if self._non_static_members:
            self._write('union { struct {')
            for i in self._non_static_members:
                if isinstance(i, member_defs.Field):
                    self._write_doc(i.name)
                    self._write('%s%s %s;', i.dtype.cname_attr, i.dtype.cname, i.name)
                else:
                    assert isinstance(i, (member_defs.Enum, member_defs.EnumAlias))
                    self._write('%s %s;', i.name, i.name_field)
            self._write('}; };')
        if self._ctor_args:
            pdefs, varnames = zip(*self._ctor_args)
            self._write('%s(%s) {', p.name, ', '.join(pdefs), indent=1)
            self._write('memset(this, 0, sizeof(*this));')
            for var in varnames:
                self._write('this->%s = %s_;', var, var)
            self._write('}', indent=-1)
        self._write('};\n', indent=-1)

    def _on_member_enum(self, e):
        self._write_doc(e.name)
        self._write('enum class %s: uint32_t {', e.name, indent=1)
        for i in e.members:
            self._write_doc(i)
            v = str(i)
            if i is not e.members[-1] or e.member_alias:
                v += ','
            self._write(v)
        for mem, alias in e.member_alias:
            if e.combined:
                self._write('%s = %s,', alias, e.compose_combined_enum(mem))
            else:
                self._write('%s = %s,', str(alias).split(' ')[0].split('=')[0], str(mem).split(' ')[0].split('=')[0])
        self._write('};', indent=-1)
        self._non_static_members.append(e)
        self._write('static MEGDNN_CONSTEXPR uint32_t %s_NR_MEMBER = %d;',
                    str(e.name).upper(), len(e.members))
        if e.combined:
            default = 'static_cast<{}>({})'.format(e.name, e.compose_combined_enum(e.default))
        else:
            value = str(e.members[e.default])
            value = value.split(' ')[0].split('=')[0]
            default = '{}::{}'.format(e.name, value)
        self._add_ctor_args(e.name, default, e.name_field)

    def _on_member_enum_alias(self, e):
        s = e.src_enum
        self._write('using %s = %s::%s;', e.name, e.src_class, e.src_name)
        self._non_static_members.append(e)
        self._write('static MEGDNN_CONSTEXPR uint32_t %s_NR_MEMBER = %d;',
                    str(e.name).upper(), len(s.members))
        if s.combined:
            default = 'static_cast<{}>({})'.format(e.name, s.compose_combined_enum(e.default))
        else:
            value = str(s.members[e.get_default()])
            value = value.split(' ')[0].split('=')[0]
            default = '{}::{}'.format(e.name, value)
        self._add_ctor_args(e.name, default, e.name_field)

    def _on_member_field(self, f):
        self._non_static_members.append(f)
        self._add_ctor_args(f.dtype.cname, f.default, f.name)

    def _on_const_field(self, f):
        self._write_doc(f.name)
        if 'int' in f.dtype.cname:
            self._write('static constexpr %s%s %s = %s;', f.dtype.cname_attr, f.dtype.cname, f.name, f.default)
        else:
            self._write('static const %s%s %s = %s;', f.dtype.cname_attr, f.dtype.cname, f.name, f.default)



class CPPEnumValueWriter(CPPWriter):
    _param_namespace = 'param_enumv'

    def _on_member_enum(self, e):
        self._write_doc(e.name)
        self._write('struct %s {', e.name, indent=1)
        for val in e.members:
            self._write_doc(val)
            v = str(val)
            self._write('static const uint32_t %s;', v)
        for mem, alias in e.member_alias:
            self._write('static const uint32_t %s = %s;', str(alias).split(' ')[0].split('=')[0], str(mem).split(' ')[0].split('=')[0])
        self._write('};', indent=-1)

    def _on_member_enum_alias(self, e):
        s = e.src_enum
        self._write('typedef %s::%s %s;', e.src_class, e.src_name, e.name)

    def _on_member_field(self, f):
        pass

    def _on_const_field(self, f):
        pass


class CPPEnumItemWriter(WriterBase):
    _class_name = None
    _enum_name = None
    _enable = False

    def __init__(self, enum_def):
        self._class_name, self._enum_name = enum_def.split(':')

    def __call__(self, fout, defs):
        super().__call__(fout)
        self._process(defs)

    def _on_param_begin(self, p):
        self._enable = p.name == self._class_name

    def _on_member_enum(self, e):
        if self._enable and e.name == self._enum_name:
            for i in e.members:
                self._fout.write('{}\n'.format(i))

class CPPParamJsonFuncWriter(IndentWriterBase):
    _param_namespace = 'param'
    _param_name = None
    _items = None
    def _write_json_item(self, json_cls, field):
        cls2ctype = {
            'NumberInt': 'int64_t',
            'Number': 'double',
            'Bool': 'bool',
        }
        self._items.append('{"%s", json::%s::make(static_cast<%s>(p.%s))},' % (
            field, json_cls, cls2ctype[json_cls], field))


    def __call__(self, fout, defs):
        super().__call__(fout)
        self._write('// %s', self._get_header())
        self._write('// this file can only be included in '
                    'megbrain/src/plugin/impl/opr_footprint.cpp\n'
                    '// please do not include it directly')
        self._write('#include "megdnn/opr_param_defs.h"')
        self._write('#pragma once')
        self._write('using namespace megdnn;')
        self._write('namespace mgb {')
        self._write('namespace opr {')
        self._write('template<class OprParam>')
        self._write('std::shared_ptr<mgb::json::Value> opr_param_to_json(const OprParam &param);')
        self._process(defs)
        self._write('} // namespace opr')
        self._write('} // namespace mgb')
        self._write('\n// vim: syntax=cpp.doxygen')

    def _on_param_begin(self, p):
        self._write('template<>', indent=0)
        self._write(
            'std::shared_ptr<mgb::json::Value> opr_param_to_json(const param::%s &p) {',
            p.name, indent=1)
        self._param_name = 'param::{}'.format(p.name)
        self._items = []

    def _on_param_end(self, p):
        self._write('return json::Object::make({', indent=1)
        for i in self._items:
            self._write(i, indent=0)
        self._write('});', indent=-1)
        self._write('}', indent=-1)

    def _on_member_enum(self, e):
        self._write('auto %s2str = [](const %s::%s arg) -> std::string {',
                    e.name, self._param_name, e.name, indent=1)
        self._write('switch (arg) {', indent=1)
        enum2str = []
        if isinstance(e, member_defs.EnumAlias):
            members = e.src_enum.members
        else:
            members = e.members
        for i in members:
            v = str(i)
            v = v.split(' ')[0].split('=')[0]
            self._write('case %s::%s::%s: return "%s";',
                        self._param_name, e.name, v, v, indent=0)
        self._write('default: mgb_throw(MegBrainError, "Invalid %s::%s:%%d", static_cast<int>(arg));',
                    self._param_name, e.name, indent=0)
        self._write('}', indent=-1)
        self._write('};', indent=-1)
        self._items.append('{"%s", json::String::make(%s2str(p.%s))},' % (
            e.name_field, e.name, e.name_field))

    def _on_member_enum_alias(self, e):
        self._on_member_enum(e)

    def _on_member_field(self, f):
        self._write_json_item(f.dtype.cppjson, f.name)

    def _on_const_field(self, f):
        pass


def main():
    parser = argparse.ArgumentParser(
        'generate opr param defs from description file')
    parser.add_argument('--enumv', action='store_true',
                        help='generate c++03 compatible code which only '
                        'contains enum values')
    parser.add_argument('-t', '--type', choices=['c++', 'py'], default='c++',
                        help='output type')
    parser.add_argument('--write-enum-items',
                        help='write enum item names to output file; argument '
                        'should be given in the CLASS:ENUM format')
    parser.add_argument('--write-cppjson',
                        help='generate megbrain json serialization implemention'
                        'cpp file')
    parser.add_argument('input')
    parser.add_argument('output')
    parser.add_argument('--imperative', action='store_true',
                        help='generate files for imperatvie ')
    args = parser.parse_args()

    for_imperative = args.imperative

    with open(args.input) as fin:
        inputs = fin.read()
        exec(inputs, {'pdef': ParamDef, 'Doc': member_defs.Doc})
        input_hash = hashlib.sha256()
        input_hash.update(inputs.encode(encoding='UTF-8'))
        input_hash = input_hash.hexdigest()

    if args.type == 'py':
        writer = PyWriter(for_imperative=for_imperative)
    else:
        assert args.type == 'c++'
        if args.enumv:
            writer = CPPEnumValueWriter()
        elif args.write_enum_items:
            writer = CPPEnumItemWriter(args.write_enum_items)
        else:
            writer = CPPWriter()
    with open(args.output, 'w') as fout:
        writer.set_input_hash(input_hash)(fout, ParamDef.all_param_defs)

    if args.write_cppjson:
        writer = CPPParamJsonFuncWriter()
        with open(args.write_cppjson, 'w') as fout:
            writer.set_input_hash(input_hash)(fout, ParamDef.all_param_defs)

if __name__ == '__main__':
    main()