xref: /openbmc/qemu/scripts/qapi/schema.py (revision e2bbc4eaa7f0d8efb8f49705bae0fecd3356f417)
1# -*- coding: utf-8 -*-
2#
3# QAPI schema internal representation
4#
5# Copyright (c) 2015-2019 Red Hat Inc.
6#
7# Authors:
8#  Markus Armbruster <armbru@redhat.com>
9#  Eric Blake <eblake@redhat.com>
10#  Marc-André Lureau <marcandre.lureau@redhat.com>
11#
12# This work is licensed under the terms of the GNU GPL, version 2.
13# See the COPYING file in the top-level directory.
14
15# TODO catching name collisions in generated code would be nice
16
17from collections import OrderedDict
18import os
19import re
20from typing import Optional
21
22from .common import POINTER_SUFFIX, c_name
23from .error import QAPIError, QAPISemError
24from .expr import check_exprs
25from .parser import QAPISchemaParser
26
27
28class QAPISchemaEntity:
29    meta: Optional[str] = None
30
31    def __init__(self, name, info, doc, ifcond=None, features=None):
32        assert name is None or isinstance(name, str)
33        for f in features or []:
34            assert isinstance(f, QAPISchemaFeature)
35            f.set_defined_in(name)
36        self.name = name
37        self._module = None
38        # For explicitly defined entities, info points to the (explicit)
39        # definition.  For builtins (and their arrays), info is None.
40        # For implicitly defined entities, info points to a place that
41        # triggered the implicit definition (there may be more than one
42        # such place).
43        self.info = info
44        self.doc = doc
45        self._ifcond = ifcond or []
46        self.features = features or []
47        self._checked = False
48
49    def c_name(self):
50        return c_name(self.name)
51
52    def check(self, schema):
53        assert not self._checked
54        seen = {}
55        for f in self.features:
56            f.check_clash(self.info, seen)
57        self._checked = True
58
59    def connect_doc(self, doc=None):
60        doc = doc or self.doc
61        if doc:
62            for f in self.features:
63                doc.connect_feature(f)
64
65    def check_doc(self):
66        if self.doc:
67            self.doc.check()
68
69    def _set_module(self, schema, info):
70        assert self._checked
71        fname = info.fname if info else './builtin'
72        self._module = schema.module_by_fname(fname)
73        self._module.add_entity(self)
74
75    def set_module(self, schema):
76        self._set_module(schema, self.info)
77
78    @property
79    def ifcond(self):
80        assert self._checked
81        return self._ifcond
82
83    def is_implicit(self):
84        return not self.info
85
86    def visit(self, visitor):
87        assert self._checked
88
89    def describe(self):
90        assert self.meta
91        return "%s '%s'" % (self.meta, self.name)
92
93
94class QAPISchemaVisitor:
95    def visit_begin(self, schema):
96        pass
97
98    def visit_end(self):
99        pass
100
101    def visit_module(self, name):
102        pass
103
104    def visit_needed(self, entity):
105        # Default to visiting everything
106        return True
107
108    def visit_include(self, name, info):
109        pass
110
111    def visit_builtin_type(self, name, info, json_type):
112        pass
113
114    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
115        pass
116
117    def visit_array_type(self, name, info, ifcond, element_type):
118        pass
119
120    def visit_object_type(self, name, info, ifcond, features,
121                          base, members, variants):
122        pass
123
124    def visit_object_type_flat(self, name, info, ifcond, features,
125                               members, variants):
126        pass
127
128    def visit_alternate_type(self, name, info, ifcond, features, variants):
129        pass
130
131    def visit_command(self, name, info, ifcond, features,
132                      arg_type, ret_type, gen, success_response, boxed,
133                      allow_oob, allow_preconfig, coroutine):
134        pass
135
136    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
137        pass
138
139
140class QAPISchemaModule:
141    def __init__(self, name):
142        self.name = name
143        self._entity_list = []
144
145    @staticmethod
146    def is_system_module(name: str) -> bool:
147        """
148        System modules are internally defined modules.
149
150        Their names start with the "./" prefix.
151        """
152        return name.startswith('./')
153
154    @classmethod
155    def is_user_module(cls, name: str) -> bool:
156        """
157        User modules are those defined by the user in qapi JSON files.
158
159        They do not start with the "./" prefix.
160        """
161        return not cls.is_system_module(name)
162
163    @staticmethod
164    def is_builtin_module(name: str) -> bool:
165        """
166        The built-in module is a single System module for the built-in types.
167
168        It is always "./builtin".
169        """
170        return name == './builtin'
171
172    def add_entity(self, ent):
173        self._entity_list.append(ent)
174
175    def visit(self, visitor):
176        visitor.visit_module(self.name)
177        for entity in self._entity_list:
178            if visitor.visit_needed(entity):
179                entity.visit(visitor)
180
181
182class QAPISchemaInclude(QAPISchemaEntity):
183    def __init__(self, sub_module, info):
184        super().__init__(None, info, None)
185        self._sub_module = sub_module
186
187    def visit(self, visitor):
188        super().visit(visitor)
189        visitor.visit_include(self._sub_module.name, self.info)
190
191
192class QAPISchemaType(QAPISchemaEntity):
193    # Return the C type for common use.
194    # For the types we commonly box, this is a pointer type.
195    def c_type(self):
196        pass
197
198    # Return the C type to be used in a parameter list.
199    def c_param_type(self):
200        return self.c_type()
201
202    # Return the C type to be used where we suppress boxing.
203    def c_unboxed_type(self):
204        return self.c_type()
205
206    def json_type(self):
207        pass
208
209    def alternate_qtype(self):
210        json2qtype = {
211            'null':    'QTYPE_QNULL',
212            'string':  'QTYPE_QSTRING',
213            'number':  'QTYPE_QNUM',
214            'int':     'QTYPE_QNUM',
215            'boolean': 'QTYPE_QBOOL',
216            'object':  'QTYPE_QDICT'
217        }
218        return json2qtype.get(self.json_type())
219
220    def doc_type(self):
221        if self.is_implicit():
222            return None
223        return self.name
224
225    def check(self, schema):
226        QAPISchemaEntity.check(self, schema)
227        if 'deprecated' in [f.name for f in self.features]:
228            raise QAPISemError(
229                self.info, "feature 'deprecated' is not supported for types")
230
231    def describe(self):
232        assert self.meta
233        return "%s type '%s'" % (self.meta, self.name)
234
235
236class QAPISchemaBuiltinType(QAPISchemaType):
237    meta = 'built-in'
238
239    def __init__(self, name, json_type, c_type):
240        super().__init__(name, None, None)
241        assert not c_type or isinstance(c_type, str)
242        assert json_type in ('string', 'number', 'int', 'boolean', 'null',
243                             'value')
244        self._json_type_name = json_type
245        self._c_type_name = c_type
246
247    def c_name(self):
248        return self.name
249
250    def c_type(self):
251        return self._c_type_name
252
253    def c_param_type(self):
254        if self.name == 'str':
255            return 'const ' + self._c_type_name
256        return self._c_type_name
257
258    def json_type(self):
259        return self._json_type_name
260
261    def doc_type(self):
262        return self.json_type()
263
264    def visit(self, visitor):
265        super().visit(visitor)
266        visitor.visit_builtin_type(self.name, self.info, self.json_type())
267
268
269class QAPISchemaEnumType(QAPISchemaType):
270    meta = 'enum'
271
272    def __init__(self, name, info, doc, ifcond, features, members, prefix):
273        super().__init__(name, info, doc, ifcond, features)
274        for m in members:
275            assert isinstance(m, QAPISchemaEnumMember)
276            m.set_defined_in(name)
277        assert prefix is None or isinstance(prefix, str)
278        self.members = members
279        self.prefix = prefix
280
281    def check(self, schema):
282        super().check(schema)
283        seen = {}
284        for m in self.members:
285            m.check_clash(self.info, seen)
286
287    def connect_doc(self, doc=None):
288        super().connect_doc(doc)
289        doc = doc or self.doc
290        for m in self.members:
291            m.connect_doc(doc)
292
293    def is_implicit(self):
294        # See QAPISchema._make_implicit_enum_type() and ._def_predefineds()
295        return self.name.endswith('Kind') or self.name == 'QType'
296
297    def c_type(self):
298        return c_name(self.name)
299
300    def member_names(self):
301        return [m.name for m in self.members]
302
303    def json_type(self):
304        return 'string'
305
306    def visit(self, visitor):
307        super().visit(visitor)
308        visitor.visit_enum_type(
309            self.name, self.info, self.ifcond, self.features,
310            self.members, self.prefix)
311
312
313class QAPISchemaArrayType(QAPISchemaType):
314    meta = 'array'
315
316    def __init__(self, name, info, element_type):
317        super().__init__(name, info, None)
318        assert isinstance(element_type, str)
319        self._element_type_name = element_type
320        self.element_type = None
321
322    def check(self, schema):
323        super().check(schema)
324        self.element_type = schema.resolve_type(
325            self._element_type_name, self.info,
326            self.info and self.info.defn_meta)
327        assert not isinstance(self.element_type, QAPISchemaArrayType)
328
329    def set_module(self, schema):
330        self._set_module(schema, self.element_type.info)
331
332    @property
333    def ifcond(self):
334        assert self._checked
335        return self.element_type.ifcond
336
337    def is_implicit(self):
338        return True
339
340    def c_type(self):
341        return c_name(self.name) + POINTER_SUFFIX
342
343    def json_type(self):
344        return 'array'
345
346    def doc_type(self):
347        elt_doc_type = self.element_type.doc_type()
348        if not elt_doc_type:
349            return None
350        return 'array of ' + elt_doc_type
351
352    def visit(self, visitor):
353        super().visit(visitor)
354        visitor.visit_array_type(self.name, self.info, self.ifcond,
355                                 self.element_type)
356
357    def describe(self):
358        assert self.meta
359        return "%s type ['%s']" % (self.meta, self._element_type_name)
360
361
362class QAPISchemaObjectType(QAPISchemaType):
363    def __init__(self, name, info, doc, ifcond, features,
364                 base, local_members, variants):
365        # struct has local_members, optional base, and no variants
366        # flat union has base, variants, and no local_members
367        # simple union has local_members, variants, and no base
368        super().__init__(name, info, doc, ifcond, features)
369        self.meta = 'union' if variants else 'struct'
370        assert base is None or isinstance(base, str)
371        for m in local_members:
372            assert isinstance(m, QAPISchemaObjectTypeMember)
373            m.set_defined_in(name)
374        if variants is not None:
375            assert isinstance(variants, QAPISchemaVariants)
376            variants.set_defined_in(name)
377        self._base_name = base
378        self.base = None
379        self.local_members = local_members
380        self.variants = variants
381        self.members = None
382
383    def check(self, schema):
384        # This calls another type T's .check() exactly when the C
385        # struct emitted by gen_object() contains that T's C struct
386        # (pointers don't count).
387        if self.members is not None:
388            # A previous .check() completed: nothing to do
389            return
390        if self._checked:
391            # Recursed: C struct contains itself
392            raise QAPISemError(self.info,
393                               "object %s contains itself" % self.name)
394
395        super().check(schema)
396        assert self._checked and self.members is None
397
398        seen = OrderedDict()
399        if self._base_name:
400            self.base = schema.resolve_type(self._base_name, self.info,
401                                            "'base'")
402            if (not isinstance(self.base, QAPISchemaObjectType)
403                    or self.base.variants):
404                raise QAPISemError(
405                    self.info,
406                    "'base' requires a struct type, %s isn't"
407                    % self.base.describe())
408            self.base.check(schema)
409            self.base.check_clash(self.info, seen)
410        for m in self.local_members:
411            m.check(schema)
412            m.check_clash(self.info, seen)
413        members = seen.values()
414
415        if self.variants:
416            self.variants.check(schema, seen)
417            self.variants.check_clash(self.info, seen)
418
419        self.members = members  # mark completed
420
421    # Check that the members of this type do not cause duplicate JSON members,
422    # and update seen to track the members seen so far. Report any errors
423    # on behalf of info, which is not necessarily self.info
424    def check_clash(self, info, seen):
425        assert self._checked
426        assert not self.variants       # not implemented
427        for m in self.members:
428            m.check_clash(info, seen)
429
430    def connect_doc(self, doc=None):
431        super().connect_doc(doc)
432        doc = doc or self.doc
433        if self.base and self.base.is_implicit():
434            self.base.connect_doc(doc)
435        for m in self.local_members:
436            m.connect_doc(doc)
437
438    @property
439    def ifcond(self):
440        assert self._checked
441        if isinstance(self._ifcond, QAPISchemaType):
442            # Simple union wrapper type inherits from wrapped type;
443            # see _make_implicit_object_type()
444            return self._ifcond.ifcond
445        return self._ifcond
446
447    def is_implicit(self):
448        # See QAPISchema._make_implicit_object_type(), as well as
449        # _def_predefineds()
450        return self.name.startswith('q_')
451
452    def is_empty(self):
453        assert self.members is not None
454        return not self.members and not self.variants
455
456    def c_name(self):
457        assert self.name != 'q_empty'
458        return super().c_name()
459
460    def c_type(self):
461        assert not self.is_implicit()
462        return c_name(self.name) + POINTER_SUFFIX
463
464    def c_unboxed_type(self):
465        return c_name(self.name)
466
467    def json_type(self):
468        return 'object'
469
470    def visit(self, visitor):
471        super().visit(visitor)
472        visitor.visit_object_type(
473            self.name, self.info, self.ifcond, self.features,
474            self.base, self.local_members, self.variants)
475        visitor.visit_object_type_flat(
476            self.name, self.info, self.ifcond, self.features,
477            self.members, self.variants)
478
479
480class QAPISchemaAlternateType(QAPISchemaType):
481    meta = 'alternate'
482
483    def __init__(self, name, info, doc, ifcond, features, variants):
484        super().__init__(name, info, doc, ifcond, features)
485        assert isinstance(variants, QAPISchemaVariants)
486        assert variants.tag_member
487        variants.set_defined_in(name)
488        variants.tag_member.set_defined_in(self.name)
489        self.variants = variants
490
491    def check(self, schema):
492        super().check(schema)
493        self.variants.tag_member.check(schema)
494        # Not calling self.variants.check_clash(), because there's nothing
495        # to clash with
496        self.variants.check(schema, {})
497        # Alternate branch names have no relation to the tag enum values;
498        # so we have to check for potential name collisions ourselves.
499        seen = {}
500        types_seen = {}
501        for v in self.variants.variants:
502            v.check_clash(self.info, seen)
503            qtype = v.type.alternate_qtype()
504            if not qtype:
505                raise QAPISemError(
506                    self.info,
507                    "%s cannot use %s"
508                    % (v.describe(self.info), v.type.describe()))
509            conflicting = set([qtype])
510            if qtype == 'QTYPE_QSTRING':
511                if isinstance(v.type, QAPISchemaEnumType):
512                    for m in v.type.members:
513                        if m.name in ['on', 'off']:
514                            conflicting.add('QTYPE_QBOOL')
515                        if re.match(r'[-+0-9.]', m.name):
516                            # lazy, could be tightened
517                            conflicting.add('QTYPE_QNUM')
518                else:
519                    conflicting.add('QTYPE_QNUM')
520                    conflicting.add('QTYPE_QBOOL')
521            for qt in conflicting:
522                if qt in types_seen:
523                    raise QAPISemError(
524                        self.info,
525                        "%s can't be distinguished from '%s'"
526                        % (v.describe(self.info), types_seen[qt]))
527                types_seen[qt] = v.name
528
529    def connect_doc(self, doc=None):
530        super().connect_doc(doc)
531        doc = doc or self.doc
532        for v in self.variants.variants:
533            v.connect_doc(doc)
534
535    def c_type(self):
536        return c_name(self.name) + POINTER_SUFFIX
537
538    def json_type(self):
539        return 'value'
540
541    def visit(self, visitor):
542        super().visit(visitor)
543        visitor.visit_alternate_type(
544            self.name, self.info, self.ifcond, self.features, self.variants)
545
546
547class QAPISchemaVariants:
548    def __init__(self, tag_name, info, tag_member, variants):
549        # Flat unions pass tag_name but not tag_member.
550        # Simple unions and alternates pass tag_member but not tag_name.
551        # After check(), tag_member is always set, and tag_name remains
552        # a reliable witness of being used by a flat union.
553        assert bool(tag_member) != bool(tag_name)
554        assert (isinstance(tag_name, str) or
555                isinstance(tag_member, QAPISchemaObjectTypeMember))
556        for v in variants:
557            assert isinstance(v, QAPISchemaVariant)
558        self._tag_name = tag_name
559        self.info = info
560        self.tag_member = tag_member
561        self.variants = variants
562
563    def set_defined_in(self, name):
564        for v in self.variants:
565            v.set_defined_in(name)
566
567    def check(self, schema, seen):
568        if not self.tag_member:  # flat union
569            self.tag_member = seen.get(c_name(self._tag_name))
570            base = "'base'"
571            # Pointing to the base type when not implicit would be
572            # nice, but we don't know it here
573            if not self.tag_member or self._tag_name != self.tag_member.name:
574                raise QAPISemError(
575                    self.info,
576                    "discriminator '%s' is not a member of %s"
577                    % (self._tag_name, base))
578            # Here we do:
579            base_type = schema.lookup_type(self.tag_member.defined_in)
580            assert base_type
581            if not base_type.is_implicit():
582                base = "base type '%s'" % self.tag_member.defined_in
583            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
584                raise QAPISemError(
585                    self.info,
586                    "discriminator member '%s' of %s must be of enum type"
587                    % (self._tag_name, base))
588            if self.tag_member.optional:
589                raise QAPISemError(
590                    self.info,
591                    "discriminator member '%s' of %s must not be optional"
592                    % (self._tag_name, base))
593            if self.tag_member.ifcond:
594                raise QAPISemError(
595                    self.info,
596                    "discriminator member '%s' of %s must not be conditional"
597                    % (self._tag_name, base))
598        else:                   # simple union
599            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
600            assert not self.tag_member.optional
601            assert self.tag_member.ifcond == []
602        if self._tag_name:    # flat union
603            # branches that are not explicitly covered get an empty type
604            cases = {v.name for v in self.variants}
605            for m in self.tag_member.type.members:
606                if m.name not in cases:
607                    v = QAPISchemaVariant(m.name, self.info,
608                                          'q_empty', m.ifcond)
609                    v.set_defined_in(self.tag_member.defined_in)
610                    self.variants.append(v)
611        if not self.variants:
612            raise QAPISemError(self.info, "union has no branches")
613        for v in self.variants:
614            v.check(schema)
615            # Union names must match enum values; alternate names are
616            # checked separately. Use 'seen' to tell the two apart.
617            if seen:
618                if v.name not in self.tag_member.type.member_names():
619                    raise QAPISemError(
620                        self.info,
621                        "branch '%s' is not a value of %s"
622                        % (v.name, self.tag_member.type.describe()))
623                if (not isinstance(v.type, QAPISchemaObjectType)
624                        or v.type.variants):
625                    raise QAPISemError(
626                        self.info,
627                        "%s cannot use %s"
628                        % (v.describe(self.info), v.type.describe()))
629                v.type.check(schema)
630
631    def check_clash(self, info, seen):
632        for v in self.variants:
633            # Reset seen map for each variant, since qapi names from one
634            # branch do not affect another branch
635            v.type.check_clash(info, dict(seen))
636
637
638class QAPISchemaMember:
639    """ Represents object members, enum members and features """
640    role = 'member'
641
642    def __init__(self, name, info, ifcond=None):
643        assert isinstance(name, str)
644        self.name = name
645        self.info = info
646        self.ifcond = ifcond or []
647        self.defined_in = None
648
649    def set_defined_in(self, name):
650        assert not self.defined_in
651        self.defined_in = name
652
653    def check_clash(self, info, seen):
654        cname = c_name(self.name)
655        if cname in seen:
656            raise QAPISemError(
657                info,
658                "%s collides with %s"
659                % (self.describe(info), seen[cname].describe(info)))
660        seen[cname] = self
661
662    def connect_doc(self, doc):
663        if doc:
664            doc.connect_member(self)
665
666    def describe(self, info):
667        role = self.role
668        defined_in = self.defined_in
669        assert defined_in
670
671        if defined_in.startswith('q_obj_'):
672            # See QAPISchema._make_implicit_object_type() - reverse the
673            # mapping there to create a nice human-readable description
674            defined_in = defined_in[6:]
675            if defined_in.endswith('-arg'):
676                # Implicit type created for a command's dict 'data'
677                assert role == 'member'
678                role = 'parameter'
679            elif defined_in.endswith('-base'):
680                # Implicit type created for a flat union's dict 'base'
681                role = 'base ' + role
682            else:
683                # Implicit type created for a simple union's branch
684                assert defined_in.endswith('-wrapper')
685                # Unreachable and not implemented
686                assert False
687        elif defined_in.endswith('Kind'):
688            # See QAPISchema._make_implicit_enum_type()
689            # Implicit enum created for simple union's branches
690            assert role == 'value'
691            role = 'branch'
692        elif defined_in != info.defn_name:
693            return "%s '%s' of type '%s'" % (role, self.name, defined_in)
694        return "%s '%s'" % (role, self.name)
695
696
697class QAPISchemaEnumMember(QAPISchemaMember):
698    role = 'value'
699
700
701class QAPISchemaFeature(QAPISchemaMember):
702    role = 'feature'
703
704
705class QAPISchemaObjectTypeMember(QAPISchemaMember):
706    def __init__(self, name, info, typ, optional, ifcond=None, features=None):
707        super().__init__(name, info, ifcond)
708        assert isinstance(typ, str)
709        assert isinstance(optional, bool)
710        for f in features or []:
711            assert isinstance(f, QAPISchemaFeature)
712            f.set_defined_in(name)
713        self._type_name = typ
714        self.type = None
715        self.optional = optional
716        self.features = features or []
717
718    def check(self, schema):
719        assert self.defined_in
720        self.type = schema.resolve_type(self._type_name, self.info,
721                                        self.describe)
722        seen = {}
723        for f in self.features:
724            f.check_clash(self.info, seen)
725
726    def connect_doc(self, doc):
727        super().connect_doc(doc)
728        if doc:
729            for f in self.features:
730                doc.connect_feature(f)
731
732
733class QAPISchemaVariant(QAPISchemaObjectTypeMember):
734    role = 'branch'
735
736    def __init__(self, name, info, typ, ifcond=None):
737        super().__init__(name, info, typ, False, ifcond)
738
739
740class QAPISchemaCommand(QAPISchemaEntity):
741    meta = 'command'
742
743    def __init__(self, name, info, doc, ifcond, features,
744                 arg_type, ret_type,
745                 gen, success_response, boxed, allow_oob, allow_preconfig,
746                 coroutine):
747        super().__init__(name, info, doc, ifcond, features)
748        assert not arg_type or isinstance(arg_type, str)
749        assert not ret_type or isinstance(ret_type, str)
750        self._arg_type_name = arg_type
751        self.arg_type = None
752        self._ret_type_name = ret_type
753        self.ret_type = None
754        self.gen = gen
755        self.success_response = success_response
756        self.boxed = boxed
757        self.allow_oob = allow_oob
758        self.allow_preconfig = allow_preconfig
759        self.coroutine = coroutine
760
761    def check(self, schema):
762        super().check(schema)
763        if self._arg_type_name:
764            self.arg_type = schema.resolve_type(
765                self._arg_type_name, self.info, "command's 'data'")
766            if not isinstance(self.arg_type, QAPISchemaObjectType):
767                raise QAPISemError(
768                    self.info,
769                    "command's 'data' cannot take %s"
770                    % self.arg_type.describe())
771            if self.arg_type.variants and not self.boxed:
772                raise QAPISemError(
773                    self.info,
774                    "command's 'data' can take %s only with 'boxed': true"
775                    % self.arg_type.describe())
776        if self._ret_type_name:
777            self.ret_type = schema.resolve_type(
778                self._ret_type_name, self.info, "command's 'returns'")
779            if self.name not in self.info.pragma.returns_whitelist:
780                typ = self.ret_type
781                if isinstance(typ, QAPISchemaArrayType):
782                    typ = self.ret_type.element_type
783                    assert typ
784                if not isinstance(typ, QAPISchemaObjectType):
785                    raise QAPISemError(
786                        self.info,
787                        "command's 'returns' cannot take %s"
788                        % self.ret_type.describe())
789
790    def connect_doc(self, doc=None):
791        super().connect_doc(doc)
792        doc = doc or self.doc
793        if doc:
794            if self.arg_type and self.arg_type.is_implicit():
795                self.arg_type.connect_doc(doc)
796
797    def visit(self, visitor):
798        super().visit(visitor)
799        visitor.visit_command(
800            self.name, self.info, self.ifcond, self.features,
801            self.arg_type, self.ret_type, self.gen, self.success_response,
802            self.boxed, self.allow_oob, self.allow_preconfig,
803            self.coroutine)
804
805
806class QAPISchemaEvent(QAPISchemaEntity):
807    meta = 'event'
808
809    def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
810        super().__init__(name, info, doc, ifcond, features)
811        assert not arg_type or isinstance(arg_type, str)
812        self._arg_type_name = arg_type
813        self.arg_type = None
814        self.boxed = boxed
815
816    def check(self, schema):
817        super().check(schema)
818        if self._arg_type_name:
819            self.arg_type = schema.resolve_type(
820                self._arg_type_name, self.info, "event's 'data'")
821            if not isinstance(self.arg_type, QAPISchemaObjectType):
822                raise QAPISemError(
823                    self.info,
824                    "event's 'data' cannot take %s"
825                    % self.arg_type.describe())
826            if self.arg_type.variants and not self.boxed:
827                raise QAPISemError(
828                    self.info,
829                    "event's 'data' can take %s only with 'boxed': true"
830                    % self.arg_type.describe())
831
832    def connect_doc(self, doc=None):
833        super().connect_doc(doc)
834        doc = doc or self.doc
835        if doc:
836            if self.arg_type and self.arg_type.is_implicit():
837                self.arg_type.connect_doc(doc)
838
839    def visit(self, visitor):
840        super().visit(visitor)
841        visitor.visit_event(
842            self.name, self.info, self.ifcond, self.features,
843            self.arg_type, self.boxed)
844
845
846class QAPISchema:
847    def __init__(self, fname):
848        self.fname = fname
849        parser = QAPISchemaParser(fname)
850        exprs = check_exprs(parser.exprs)
851        self.docs = parser.docs
852        self._entity_list = []
853        self._entity_dict = {}
854        self._module_dict = OrderedDict()
855        self._schema_dir = os.path.dirname(fname)
856        self._make_module('./builtin')
857        self._make_module(fname)
858        self._predefining = True
859        self._def_predefineds()
860        self._predefining = False
861        self._def_exprs(exprs)
862        self.check()
863
864    def _def_entity(self, ent):
865        # Only the predefined types are allowed to not have info
866        assert ent.info or self._predefining
867        self._entity_list.append(ent)
868        if ent.name is None:
869            return
870        # TODO reject names that differ only in '_' vs. '.'  vs. '-',
871        # because they're liable to clash in generated C.
872        other_ent = self._entity_dict.get(ent.name)
873        if other_ent:
874            if other_ent.info:
875                where = QAPIError(other_ent.info, None, "previous definition")
876                raise QAPISemError(
877                    ent.info,
878                    "'%s' is already defined\n%s" % (ent.name, where))
879            raise QAPISemError(
880                ent.info, "%s is already defined" % other_ent.describe())
881        self._entity_dict[ent.name] = ent
882
883    def lookup_entity(self, name, typ=None):
884        ent = self._entity_dict.get(name)
885        if typ and not isinstance(ent, typ):
886            return None
887        return ent
888
889    def lookup_type(self, name):
890        return self.lookup_entity(name, QAPISchemaType)
891
892    def resolve_type(self, name, info, what):
893        typ = self.lookup_type(name)
894        if not typ:
895            if callable(what):
896                what = what(info)
897            raise QAPISemError(
898                info, "%s uses unknown type '%s'" % (what, name))
899        return typ
900
901    def _module_name(self, fname: str) -> str:
902        if QAPISchemaModule.is_system_module(fname):
903            return fname
904        return os.path.relpath(fname, self._schema_dir)
905
906    def _make_module(self, fname):
907        name = self._module_name(fname)
908        if name not in self._module_dict:
909            self._module_dict[name] = QAPISchemaModule(name)
910        return self._module_dict[name]
911
912    def module_by_fname(self, fname):
913        name = self._module_name(fname)
914        return self._module_dict[name]
915
916    def _def_include(self, expr, info, doc):
917        include = expr['include']
918        assert doc is None
919        self._def_entity(QAPISchemaInclude(self._make_module(include), info))
920
921    def _def_builtin_type(self, name, json_type, c_type):
922        self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
923        # Instantiating only the arrays that are actually used would
924        # be nice, but we can't as long as their generated code
925        # (qapi-builtin-types.[ch]) may be shared by some other
926        # schema.
927        self._make_array_type(name, None)
928
929    def _def_predefineds(self):
930        for t in [('str',    'string',  'char' + POINTER_SUFFIX),
931                  ('number', 'number',  'double'),
932                  ('int',    'int',     'int64_t'),
933                  ('int8',   'int',     'int8_t'),
934                  ('int16',  'int',     'int16_t'),
935                  ('int32',  'int',     'int32_t'),
936                  ('int64',  'int',     'int64_t'),
937                  ('uint8',  'int',     'uint8_t'),
938                  ('uint16', 'int',     'uint16_t'),
939                  ('uint32', 'int',     'uint32_t'),
940                  ('uint64', 'int',     'uint64_t'),
941                  ('size',   'int',     'uint64_t'),
942                  ('bool',   'boolean', 'bool'),
943                  ('any',    'value',   'QObject' + POINTER_SUFFIX),
944                  ('null',   'null',    'QNull' + POINTER_SUFFIX)]:
945            self._def_builtin_type(*t)
946        self.the_empty_object_type = QAPISchemaObjectType(
947            'q_empty', None, None, None, None, None, [], None)
948        self._def_entity(self.the_empty_object_type)
949
950        qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
951                  'qbool']
952        qtype_values = self._make_enum_members(
953            [{'name': n} for n in qtypes], None)
954
955        self._def_entity(QAPISchemaEnumType('QType', None, None, None, None,
956                                            qtype_values, 'QTYPE'))
957
958    def _make_features(self, features, info):
959        if features is None:
960            return []
961        return [QAPISchemaFeature(f['name'], info, f.get('if'))
962                for f in features]
963
964    def _make_enum_members(self, values, info):
965        return [QAPISchemaEnumMember(v['name'], info, v.get('if'))
966                for v in values]
967
968    def _make_implicit_enum_type(self, name, info, ifcond, values):
969        # See also QAPISchemaObjectTypeMember.describe()
970        name = name + 'Kind'    # reserved by check_defn_name_str()
971        self._def_entity(QAPISchemaEnumType(
972            name, info, None, ifcond, None,
973            self._make_enum_members(values, info),
974            None))
975        return name
976
977    def _make_array_type(self, element_type, info):
978        name = element_type + 'List'    # reserved by check_defn_name_str()
979        if not self.lookup_type(name):
980            self._def_entity(QAPISchemaArrayType(name, info, element_type))
981        return name
982
983    def _make_implicit_object_type(self, name, info, ifcond, role, members):
984        if not members:
985            return None
986        # See also QAPISchemaObjectTypeMember.describe()
987        name = 'q_obj_%s-%s' % (name, role)
988        typ = self.lookup_entity(name, QAPISchemaObjectType)
989        if typ:
990            # The implicit object type has multiple users.  This can
991            # happen only for simple unions' implicit wrapper types.
992            # Its ifcond should be the disjunction of its user's
993            # ifconds.  Not implemented.  Instead, we always pass the
994            # wrapped type's ifcond, which is trivially the same for all
995            # users.  It's also necessary for the wrapper to compile.
996            # But it's not tight: the disjunction need not imply it.  We
997            # may end up compiling useless wrapper types.
998            # TODO kill simple unions or implement the disjunction
999
1000            # pylint: disable=protected-access
1001            assert (ifcond or []) == typ._ifcond
1002        else:
1003            self._def_entity(QAPISchemaObjectType(
1004                name, info, None, ifcond, None, None, members, None))
1005        return name
1006
1007    def _def_enum_type(self, expr, info, doc):
1008        name = expr['enum']
1009        data = expr['data']
1010        prefix = expr.get('prefix')
1011        ifcond = expr.get('if')
1012        features = self._make_features(expr.get('features'), info)
1013        self._def_entity(QAPISchemaEnumType(
1014            name, info, doc, ifcond, features,
1015            self._make_enum_members(data, info), prefix))
1016
1017    def _make_member(self, name, typ, ifcond, features, info):
1018        optional = False
1019        if name.startswith('*'):
1020            name = name[1:]
1021            optional = True
1022        if isinstance(typ, list):
1023            assert len(typ) == 1
1024            typ = self._make_array_type(typ[0], info)
1025        return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond,
1026                                          self._make_features(features, info))
1027
1028    def _make_members(self, data, info):
1029        return [self._make_member(key, value['type'], value.get('if'),
1030                                  value.get('features'), info)
1031                for (key, value) in data.items()]
1032
1033    def _def_struct_type(self, expr, info, doc):
1034        name = expr['struct']
1035        base = expr.get('base')
1036        data = expr['data']
1037        ifcond = expr.get('if')
1038        features = self._make_features(expr.get('features'), info)
1039        self._def_entity(QAPISchemaObjectType(
1040            name, info, doc, ifcond, features, base,
1041            self._make_members(data, info),
1042            None))
1043
1044    def _make_variant(self, case, typ, ifcond, info):
1045        return QAPISchemaVariant(case, info, typ, ifcond)
1046
1047    def _make_simple_variant(self, case, typ, ifcond, info):
1048        if isinstance(typ, list):
1049            assert len(typ) == 1
1050            typ = self._make_array_type(typ[0], info)
1051        typ = self._make_implicit_object_type(
1052            typ, info, self.lookup_type(typ),
1053            'wrapper', [self._make_member('data', typ, None, None, info)])
1054        return QAPISchemaVariant(case, info, typ, ifcond)
1055
1056    def _def_union_type(self, expr, info, doc):
1057        name = expr['union']
1058        data = expr['data']
1059        base = expr.get('base')
1060        ifcond = expr.get('if')
1061        features = self._make_features(expr.get('features'), info)
1062        tag_name = expr.get('discriminator')
1063        tag_member = None
1064        if isinstance(base, dict):
1065            base = self._make_implicit_object_type(
1066                name, info, ifcond,
1067                'base', self._make_members(base, info))
1068        if tag_name:
1069            variants = [self._make_variant(key, value['type'],
1070                                           value.get('if'), info)
1071                        for (key, value) in data.items()]
1072            members = []
1073        else:
1074            variants = [self._make_simple_variant(key, value['type'],
1075                                                  value.get('if'), info)
1076                        for (key, value) in data.items()]
1077            enum = [{'name': v.name, 'if': v.ifcond} for v in variants]
1078            typ = self._make_implicit_enum_type(name, info, ifcond, enum)
1079            tag_member = QAPISchemaObjectTypeMember('type', info, typ, False)
1080            members = [tag_member]
1081        self._def_entity(
1082            QAPISchemaObjectType(name, info, doc, ifcond, features,
1083                                 base, members,
1084                                 QAPISchemaVariants(
1085                                     tag_name, info, tag_member, variants)))
1086
1087    def _def_alternate_type(self, expr, info, doc):
1088        name = expr['alternate']
1089        data = expr['data']
1090        ifcond = expr.get('if')
1091        features = self._make_features(expr.get('features'), info)
1092        variants = [self._make_variant(key, value['type'], value.get('if'),
1093                                       info)
1094                    for (key, value) in data.items()]
1095        tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1096        self._def_entity(
1097            QAPISchemaAlternateType(name, info, doc, ifcond, features,
1098                                    QAPISchemaVariants(
1099                                        None, info, tag_member, variants)))
1100
1101    def _def_command(self, expr, info, doc):
1102        name = expr['command']
1103        data = expr.get('data')
1104        rets = expr.get('returns')
1105        gen = expr.get('gen', True)
1106        success_response = expr.get('success-response', True)
1107        boxed = expr.get('boxed', False)
1108        allow_oob = expr.get('allow-oob', False)
1109        allow_preconfig = expr.get('allow-preconfig', False)
1110        coroutine = expr.get('coroutine', False)
1111        ifcond = expr.get('if')
1112        features = self._make_features(expr.get('features'), info)
1113        if isinstance(data, OrderedDict):
1114            data = self._make_implicit_object_type(
1115                name, info, ifcond,
1116                'arg', self._make_members(data, info))
1117        if isinstance(rets, list):
1118            assert len(rets) == 1
1119            rets = self._make_array_type(rets[0], info)
1120        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, features,
1121                                           data, rets,
1122                                           gen, success_response,
1123                                           boxed, allow_oob, allow_preconfig,
1124                                           coroutine))
1125
1126    def _def_event(self, expr, info, doc):
1127        name = expr['event']
1128        data = expr.get('data')
1129        boxed = expr.get('boxed', False)
1130        ifcond = expr.get('if')
1131        features = self._make_features(expr.get('features'), info)
1132        if isinstance(data, OrderedDict):
1133            data = self._make_implicit_object_type(
1134                name, info, ifcond,
1135                'arg', self._make_members(data, info))
1136        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, features,
1137                                         data, boxed))
1138
1139    def _def_exprs(self, exprs):
1140        for expr_elem in exprs:
1141            expr = expr_elem['expr']
1142            info = expr_elem['info']
1143            doc = expr_elem.get('doc')
1144            if 'enum' in expr:
1145                self._def_enum_type(expr, info, doc)
1146            elif 'struct' in expr:
1147                self._def_struct_type(expr, info, doc)
1148            elif 'union' in expr:
1149                self._def_union_type(expr, info, doc)
1150            elif 'alternate' in expr:
1151                self._def_alternate_type(expr, info, doc)
1152            elif 'command' in expr:
1153                self._def_command(expr, info, doc)
1154            elif 'event' in expr:
1155                self._def_event(expr, info, doc)
1156            elif 'include' in expr:
1157                self._def_include(expr, info, doc)
1158            else:
1159                assert False
1160
1161    def check(self):
1162        for ent in self._entity_list:
1163            ent.check(self)
1164            ent.connect_doc()
1165            ent.check_doc()
1166        for ent in self._entity_list:
1167            ent.set_module(self)
1168
1169    def visit(self, visitor):
1170        visitor.visit_begin(self)
1171        for mod in self._module_dict.values():
1172            mod.visit(visitor)
1173        visitor.visit_end()
1174