xref: /openbmc/qemu/scripts/qapi/schema.py (revision 83ecdb18)
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 List, Optional
21
22from .common import (
23    POINTER_SUFFIX,
24    c_name,
25    cgen_ifcond,
26    docgen_ifcond,
27    gen_endif,
28    gen_if,
29)
30from .error import QAPIError, QAPISemError, QAPISourceError
31from .expr import check_exprs
32from .parser import QAPIExpression, QAPISchemaParser
33
34
35class QAPISchemaIfCond:
36    def __init__(self, ifcond=None):
37        self.ifcond = ifcond
38
39    def _cgen(self):
40        return cgen_ifcond(self.ifcond)
41
42    def gen_if(self):
43        return gen_if(self._cgen())
44
45    def gen_endif(self):
46        return gen_endif(self._cgen())
47
48    def docgen(self):
49        return docgen_ifcond(self.ifcond)
50
51    def is_present(self):
52        return bool(self.ifcond)
53
54
55class QAPISchemaEntity:
56    meta: Optional[str] = None
57
58    def __init__(self, name: str, info, doc, ifcond=None, features=None):
59        assert name is None or isinstance(name, str)
60        for f in features or []:
61            assert isinstance(f, QAPISchemaFeature)
62            f.set_defined_in(name)
63        self.name = name
64        self._module = None
65        # For explicitly defined entities, info points to the (explicit)
66        # definition.  For builtins (and their arrays), info is None.
67        # For implicitly defined entities, info points to a place that
68        # triggered the implicit definition (there may be more than one
69        # such place).
70        self.info = info
71        self.doc = doc
72        self._ifcond = ifcond or QAPISchemaIfCond()
73        self.features = features or []
74        self._checked = False
75
76    def c_name(self):
77        return c_name(self.name)
78
79    def check(self, schema):
80        assert not self._checked
81        seen = {}
82        for f in self.features:
83            f.check_clash(self.info, seen)
84        self._checked = True
85
86    def connect_doc(self, doc=None):
87        doc = doc or self.doc
88        if doc:
89            for f in self.features:
90                doc.connect_feature(f)
91
92    def check_doc(self):
93        if self.doc:
94            self.doc.check()
95
96    def _set_module(self, schema, info):
97        assert self._checked
98        fname = info.fname if info else QAPISchemaModule.BUILTIN_MODULE_NAME
99        self._module = schema.module_by_fname(fname)
100        self._module.add_entity(self)
101
102    def set_module(self, schema):
103        self._set_module(schema, self.info)
104
105    @property
106    def ifcond(self):
107        assert self._checked
108        return self._ifcond
109
110    def is_implicit(self):
111        return not self.info
112
113    def visit(self, visitor):
114        assert self._checked
115
116    def describe(self):
117        assert self.meta
118        return "%s '%s'" % (self.meta, self.name)
119
120
121class QAPISchemaVisitor:
122    def visit_begin(self, schema):
123        pass
124
125    def visit_end(self):
126        pass
127
128    def visit_module(self, name):
129        pass
130
131    def visit_needed(self, entity):
132        # Default to visiting everything
133        return True
134
135    def visit_include(self, name, info):
136        pass
137
138    def visit_builtin_type(self, name, info, json_type):
139        pass
140
141    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
142        pass
143
144    def visit_array_type(self, name, info, ifcond, element_type):
145        pass
146
147    def visit_object_type(self, name, info, ifcond, features,
148                          base, members, variants):
149        pass
150
151    def visit_object_type_flat(self, name, info, ifcond, features,
152                               members, variants):
153        pass
154
155    def visit_alternate_type(self, name, info, ifcond, features, variants):
156        pass
157
158    def visit_command(self, name, info, ifcond, features,
159                      arg_type, ret_type, gen, success_response, boxed,
160                      allow_oob, allow_preconfig, coroutine):
161        pass
162
163    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
164        pass
165
166
167class QAPISchemaModule:
168
169    BUILTIN_MODULE_NAME = './builtin'
170
171    def __init__(self, name):
172        self.name = name
173        self._entity_list = []
174
175    @staticmethod
176    def is_system_module(name: str) -> bool:
177        """
178        System modules are internally defined modules.
179
180        Their names start with the "./" prefix.
181        """
182        return name.startswith('./')
183
184    @classmethod
185    def is_user_module(cls, name: str) -> bool:
186        """
187        User modules are those defined by the user in qapi JSON files.
188
189        They do not start with the "./" prefix.
190        """
191        return not cls.is_system_module(name)
192
193    @classmethod
194    def is_builtin_module(cls, name: str) -> bool:
195        """
196        The built-in module is a single System module for the built-in types.
197
198        It is always "./builtin".
199        """
200        return name == cls.BUILTIN_MODULE_NAME
201
202    def add_entity(self, ent):
203        self._entity_list.append(ent)
204
205    def visit(self, visitor):
206        visitor.visit_module(self.name)
207        for entity in self._entity_list:
208            if visitor.visit_needed(entity):
209                entity.visit(visitor)
210
211
212class QAPISchemaInclude(QAPISchemaEntity):
213    def __init__(self, sub_module, info):
214        super().__init__(None, info, None)
215        self._sub_module = sub_module
216
217    def visit(self, visitor):
218        super().visit(visitor)
219        visitor.visit_include(self._sub_module.name, self.info)
220
221
222class QAPISchemaType(QAPISchemaEntity):
223    # Return the C type for common use.
224    # For the types we commonly box, this is a pointer type.
225    def c_type(self):
226        pass
227
228    # Return the C type to be used in a parameter list.
229    def c_param_type(self):
230        return self.c_type()
231
232    # Return the C type to be used where we suppress boxing.
233    def c_unboxed_type(self):
234        return self.c_type()
235
236    def json_type(self):
237        pass
238
239    def alternate_qtype(self):
240        json2qtype = {
241            'null':    'QTYPE_QNULL',
242            'string':  'QTYPE_QSTRING',
243            'number':  'QTYPE_QNUM',
244            'int':     'QTYPE_QNUM',
245            'boolean': 'QTYPE_QBOOL',
246            'array':   'QTYPE_QLIST',
247            'object':  'QTYPE_QDICT'
248        }
249        return json2qtype.get(self.json_type())
250
251    def doc_type(self):
252        if self.is_implicit():
253            return None
254        return self.name
255
256    def need_has_if_optional(self):
257        # When FOO is a pointer, has_FOO == !!FOO, i.e. has_FOO is redundant.
258        # Except for arrays; see QAPISchemaArrayType.need_has_if_optional().
259        return not self.c_type().endswith(POINTER_SUFFIX)
260
261    def check(self, schema):
262        super().check(schema)
263        for feat in self.features:
264            if feat.is_special():
265                raise QAPISemError(
266                    self.info,
267                    f"feature '{feat.name}' is not supported for types")
268
269    def describe(self):
270        assert self.meta
271        return "%s type '%s'" % (self.meta, self.name)
272
273
274class QAPISchemaBuiltinType(QAPISchemaType):
275    meta = 'built-in'
276
277    def __init__(self, name, json_type, c_type):
278        super().__init__(name, None, None)
279        assert not c_type or isinstance(c_type, str)
280        assert json_type in ('string', 'number', 'int', 'boolean', 'null',
281                             'value')
282        self._json_type_name = json_type
283        self._c_type_name = c_type
284
285    def c_name(self):
286        return self.name
287
288    def c_type(self):
289        return self._c_type_name
290
291    def c_param_type(self):
292        if self.name == 'str':
293            return 'const ' + self._c_type_name
294        return self._c_type_name
295
296    def json_type(self):
297        return self._json_type_name
298
299    def doc_type(self):
300        return self.json_type()
301
302    def visit(self, visitor):
303        super().visit(visitor)
304        visitor.visit_builtin_type(self.name, self.info, self.json_type())
305
306
307class QAPISchemaEnumType(QAPISchemaType):
308    meta = 'enum'
309
310    def __init__(self, name, info, doc, ifcond, features, members, prefix):
311        super().__init__(name, info, doc, ifcond, features)
312        for m in members:
313            assert isinstance(m, QAPISchemaEnumMember)
314            m.set_defined_in(name)
315        assert prefix is None or isinstance(prefix, str)
316        self.members = members
317        self.prefix = prefix
318
319    def check(self, schema):
320        super().check(schema)
321        seen = {}
322        for m in self.members:
323            m.check_clash(self.info, seen)
324
325    def connect_doc(self, doc=None):
326        super().connect_doc(doc)
327        doc = doc or self.doc
328        for m in self.members:
329            m.connect_doc(doc)
330
331    def is_implicit(self):
332        # See QAPISchema._def_predefineds()
333        return self.name == 'QType'
334
335    def c_type(self):
336        return c_name(self.name)
337
338    def member_names(self):
339        return [m.name for m in self.members]
340
341    def json_type(self):
342        return 'string'
343
344    def visit(self, visitor):
345        super().visit(visitor)
346        visitor.visit_enum_type(
347            self.name, self.info, self.ifcond, self.features,
348            self.members, self.prefix)
349
350
351class QAPISchemaArrayType(QAPISchemaType):
352    meta = 'array'
353
354    def __init__(self, name, info, element_type):
355        super().__init__(name, info, None)
356        assert isinstance(element_type, str)
357        self._element_type_name = element_type
358        self.element_type = None
359
360    def need_has_if_optional(self):
361        # When FOO is an array, we still need has_FOO to distinguish
362        # absent (!has_FOO) from present and empty (has_FOO && !FOO).
363        return True
364
365    def check(self, schema):
366        super().check(schema)
367        self.element_type = schema.resolve_type(
368            self._element_type_name, self.info,
369            self.info and self.info.defn_meta)
370        assert not isinstance(self.element_type, QAPISchemaArrayType)
371
372    def set_module(self, schema):
373        self._set_module(schema, self.element_type.info)
374
375    @property
376    def ifcond(self):
377        assert self._checked
378        return self.element_type.ifcond
379
380    def is_implicit(self):
381        return True
382
383    def c_type(self):
384        return c_name(self.name) + POINTER_SUFFIX
385
386    def json_type(self):
387        return 'array'
388
389    def doc_type(self):
390        elt_doc_type = self.element_type.doc_type()
391        if not elt_doc_type:
392            return None
393        return 'array of ' + elt_doc_type
394
395    def visit(self, visitor):
396        super().visit(visitor)
397        visitor.visit_array_type(self.name, self.info, self.ifcond,
398                                 self.element_type)
399
400    def describe(self):
401        assert self.meta
402        return "%s type ['%s']" % (self.meta, self._element_type_name)
403
404
405class QAPISchemaObjectType(QAPISchemaType):
406    def __init__(self, name, info, doc, ifcond, features,
407                 base, local_members, variants):
408        # struct has local_members, optional base, and no variants
409        # union has base, variants, and no local_members
410        super().__init__(name, info, doc, ifcond, features)
411        self.meta = 'union' if variants else 'struct'
412        assert base is None or isinstance(base, str)
413        for m in local_members:
414            assert isinstance(m, QAPISchemaObjectTypeMember)
415            m.set_defined_in(name)
416        if variants is not None:
417            assert isinstance(variants, QAPISchemaVariants)
418            variants.set_defined_in(name)
419        self._base_name = base
420        self.base = None
421        self.local_members = local_members
422        self.variants = variants
423        self.members = None
424
425    def check(self, schema):
426        # This calls another type T's .check() exactly when the C
427        # struct emitted by gen_object() contains that T's C struct
428        # (pointers don't count).
429        if self.members is not None:
430            # A previous .check() completed: nothing to do
431            return
432        if self._checked:
433            # Recursed: C struct contains itself
434            raise QAPISemError(self.info,
435                               "object %s contains itself" % self.name)
436
437        super().check(schema)
438        assert self._checked and self.members is None
439
440        seen = OrderedDict()
441        if self._base_name:
442            self.base = schema.resolve_type(self._base_name, self.info,
443                                            "'base'")
444            if (not isinstance(self.base, QAPISchemaObjectType)
445                    or self.base.variants):
446                raise QAPISemError(
447                    self.info,
448                    "'base' requires a struct type, %s isn't"
449                    % self.base.describe())
450            self.base.check(schema)
451            self.base.check_clash(self.info, seen)
452        for m in self.local_members:
453            m.check(schema)
454            m.check_clash(self.info, seen)
455        members = seen.values()
456
457        if self.variants:
458            self.variants.check(schema, seen)
459            self.variants.check_clash(self.info, seen)
460
461        self.members = members  # mark completed
462
463    # Check that the members of this type do not cause duplicate JSON members,
464    # and update seen to track the members seen so far. Report any errors
465    # on behalf of info, which is not necessarily self.info
466    def check_clash(self, info, seen):
467        assert self._checked
468        for m in self.members:
469            m.check_clash(info, seen)
470        if self.variants:
471            self.variants.check_clash(info, seen)
472
473    def connect_doc(self, doc=None):
474        super().connect_doc(doc)
475        doc = doc or self.doc
476        if self.base and self.base.is_implicit():
477            self.base.connect_doc(doc)
478        for m in self.local_members:
479            m.connect_doc(doc)
480
481    def is_implicit(self):
482        # See QAPISchema._make_implicit_object_type(), as well as
483        # _def_predefineds()
484        return self.name.startswith('q_')
485
486    def is_empty(self):
487        assert self.members is not None
488        return not self.members and not self.variants
489
490    def has_conditional_members(self):
491        assert self.members is not None
492        return any(m.ifcond.is_present() for m in self.members)
493
494    def c_name(self):
495        assert self.name != 'q_empty'
496        return super().c_name()
497
498    def c_type(self):
499        assert not self.is_implicit()
500        return c_name(self.name) + POINTER_SUFFIX
501
502    def c_unboxed_type(self):
503        return c_name(self.name)
504
505    def json_type(self):
506        return 'object'
507
508    def visit(self, visitor):
509        super().visit(visitor)
510        visitor.visit_object_type(
511            self.name, self.info, self.ifcond, self.features,
512            self.base, self.local_members, self.variants)
513        visitor.visit_object_type_flat(
514            self.name, self.info, self.ifcond, self.features,
515            self.members, self.variants)
516
517
518class QAPISchemaAlternateType(QAPISchemaType):
519    meta = 'alternate'
520
521    def __init__(self, name, info, doc, ifcond, features, variants):
522        super().__init__(name, info, doc, ifcond, features)
523        assert isinstance(variants, QAPISchemaVariants)
524        assert variants.tag_member
525        variants.set_defined_in(name)
526        variants.tag_member.set_defined_in(self.name)
527        self.variants = variants
528
529    def check(self, schema):
530        super().check(schema)
531        self.variants.tag_member.check(schema)
532        # Not calling self.variants.check_clash(), because there's nothing
533        # to clash with
534        self.variants.check(schema, {})
535        # Alternate branch names have no relation to the tag enum values;
536        # so we have to check for potential name collisions ourselves.
537        seen = {}
538        types_seen = {}
539        for v in self.variants.variants:
540            v.check_clash(self.info, seen)
541            qtype = v.type.alternate_qtype()
542            if not qtype:
543                raise QAPISemError(
544                    self.info,
545                    "%s cannot use %s"
546                    % (v.describe(self.info), v.type.describe()))
547            conflicting = set([qtype])
548            if qtype == 'QTYPE_QSTRING':
549                if isinstance(v.type, QAPISchemaEnumType):
550                    for m in v.type.members:
551                        if m.name in ['on', 'off']:
552                            conflicting.add('QTYPE_QBOOL')
553                        if re.match(r'[-+0-9.]', m.name):
554                            # lazy, could be tightened
555                            conflicting.add('QTYPE_QNUM')
556                else:
557                    conflicting.add('QTYPE_QNUM')
558                    conflicting.add('QTYPE_QBOOL')
559            for qt in conflicting:
560                if qt in types_seen:
561                    raise QAPISemError(
562                        self.info,
563                        "%s can't be distinguished from '%s'"
564                        % (v.describe(self.info), types_seen[qt]))
565                types_seen[qt] = v.name
566
567    def connect_doc(self, doc=None):
568        super().connect_doc(doc)
569        doc = doc or self.doc
570        for v in self.variants.variants:
571            v.connect_doc(doc)
572
573    def c_type(self):
574        return c_name(self.name) + POINTER_SUFFIX
575
576    def json_type(self):
577        return 'value'
578
579    def visit(self, visitor):
580        super().visit(visitor)
581        visitor.visit_alternate_type(
582            self.name, self.info, self.ifcond, self.features, self.variants)
583
584
585class QAPISchemaVariants:
586    def __init__(self, tag_name, info, tag_member, variants):
587        # Unions pass tag_name but not tag_member.
588        # Alternates pass tag_member but not tag_name.
589        # After check(), tag_member is always set.
590        assert bool(tag_member) != bool(tag_name)
591        assert (isinstance(tag_name, str) or
592                isinstance(tag_member, QAPISchemaObjectTypeMember))
593        for v in variants:
594            assert isinstance(v, QAPISchemaVariant)
595        self._tag_name = tag_name
596        self.info = info
597        self.tag_member = tag_member
598        self.variants = variants
599
600    def set_defined_in(self, name):
601        for v in self.variants:
602            v.set_defined_in(name)
603
604    def check(self, schema, seen):
605        if self._tag_name:      # union
606            self.tag_member = seen.get(c_name(self._tag_name))
607            base = "'base'"
608            # Pointing to the base type when not implicit would be
609            # nice, but we don't know it here
610            if not self.tag_member or self._tag_name != self.tag_member.name:
611                raise QAPISemError(
612                    self.info,
613                    "discriminator '%s' is not a member of %s"
614                    % (self._tag_name, base))
615            # Here we do:
616            base_type = schema.lookup_type(self.tag_member.defined_in)
617            assert base_type
618            if not base_type.is_implicit():
619                base = "base type '%s'" % self.tag_member.defined_in
620            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
621                raise QAPISemError(
622                    self.info,
623                    "discriminator member '%s' of %s must be of enum type"
624                    % (self._tag_name, base))
625            if self.tag_member.optional:
626                raise QAPISemError(
627                    self.info,
628                    "discriminator member '%s' of %s must not be optional"
629                    % (self._tag_name, base))
630            if self.tag_member.ifcond.is_present():
631                raise QAPISemError(
632                    self.info,
633                    "discriminator member '%s' of %s must not be conditional"
634                    % (self._tag_name, base))
635        else:                   # alternate
636            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
637            assert not self.tag_member.optional
638            assert not self.tag_member.ifcond.is_present()
639        if self._tag_name:      # union
640            # branches that are not explicitly covered get an empty type
641            cases = {v.name for v in self.variants}
642            for m in self.tag_member.type.members:
643                if m.name not in cases:
644                    v = QAPISchemaVariant(m.name, self.info,
645                                          'q_empty', m.ifcond)
646                    v.set_defined_in(self.tag_member.defined_in)
647                    self.variants.append(v)
648        if not self.variants:
649            raise QAPISemError(self.info, "union has no branches")
650        for v in self.variants:
651            v.check(schema)
652            # Union names must match enum values; alternate names are
653            # checked separately. Use 'seen' to tell the two apart.
654            if seen:
655                if v.name not in self.tag_member.type.member_names():
656                    raise QAPISemError(
657                        self.info,
658                        "branch '%s' is not a value of %s"
659                        % (v.name, self.tag_member.type.describe()))
660                if not isinstance(v.type, QAPISchemaObjectType):
661                    raise QAPISemError(
662                        self.info,
663                        "%s cannot use %s"
664                        % (v.describe(self.info), v.type.describe()))
665                v.type.check(schema)
666
667    def check_clash(self, info, seen):
668        for v in self.variants:
669            # Reset seen map for each variant, since qapi names from one
670            # branch do not affect another branch
671            v.type.check_clash(info, dict(seen))
672
673
674class QAPISchemaMember:
675    """ Represents object members, enum members and features """
676    role = 'member'
677
678    def __init__(self, name, info, ifcond=None):
679        assert isinstance(name, str)
680        self.name = name
681        self.info = info
682        self.ifcond = ifcond or QAPISchemaIfCond()
683        self.defined_in = None
684
685    def set_defined_in(self, name):
686        assert not self.defined_in
687        self.defined_in = name
688
689    def check_clash(self, info, seen):
690        cname = c_name(self.name)
691        if cname in seen:
692            raise QAPISemError(
693                info,
694                "%s collides with %s"
695                % (self.describe(info), seen[cname].describe(info)))
696        seen[cname] = self
697
698    def connect_doc(self, doc):
699        if doc:
700            doc.connect_member(self)
701
702    def describe(self, info):
703        role = self.role
704        meta = 'type'
705        defined_in = self.defined_in
706        assert defined_in
707
708        if defined_in.startswith('q_obj_'):
709            # See QAPISchema._make_implicit_object_type() - reverse the
710            # mapping there to create a nice human-readable description
711            defined_in = defined_in[6:]
712            if defined_in.endswith('-arg'):
713                # Implicit type created for a command's dict 'data'
714                assert role == 'member'
715                role = 'parameter'
716                meta = 'command'
717                defined_in = defined_in[:-4]
718            elif defined_in.endswith('-base'):
719                # Implicit type created for a union's dict 'base'
720                role = 'base ' + role
721                defined_in = defined_in[:-5]
722            else:
723                assert False
724
725        if defined_in != info.defn_name:
726            return "%s '%s' of %s '%s'" % (role, self.name, meta, defined_in)
727        return "%s '%s'" % (role, self.name)
728
729
730class QAPISchemaEnumMember(QAPISchemaMember):
731    role = 'value'
732
733    def __init__(self, name, info, ifcond=None, features=None):
734        super().__init__(name, info, ifcond)
735        for f in features or []:
736            assert isinstance(f, QAPISchemaFeature)
737            f.set_defined_in(name)
738        self.features = features or []
739
740    def connect_doc(self, doc):
741        super().connect_doc(doc)
742        if doc:
743            for f in self.features:
744                doc.connect_feature(f)
745
746
747class QAPISchemaFeature(QAPISchemaMember):
748    role = 'feature'
749
750    def is_special(self):
751        return self.name in ('deprecated', 'unstable')
752
753
754class QAPISchemaObjectTypeMember(QAPISchemaMember):
755    def __init__(self, name, info, typ, optional, ifcond=None, features=None):
756        super().__init__(name, info, ifcond)
757        assert isinstance(typ, str)
758        assert isinstance(optional, bool)
759        for f in features or []:
760            assert isinstance(f, QAPISchemaFeature)
761            f.set_defined_in(name)
762        self._type_name = typ
763        self.type = None
764        self.optional = optional
765        self.features = features or []
766
767    def need_has(self):
768        assert self.type
769        return self.optional and self.type.need_has_if_optional()
770
771    def check(self, schema):
772        assert self.defined_in
773        self.type = schema.resolve_type(self._type_name, self.info,
774                                        self.describe)
775        seen = {}
776        for f in self.features:
777            f.check_clash(self.info, seen)
778
779    def connect_doc(self, doc):
780        super().connect_doc(doc)
781        if doc:
782            for f in self.features:
783                doc.connect_feature(f)
784
785
786class QAPISchemaVariant(QAPISchemaObjectTypeMember):
787    role = 'branch'
788
789    def __init__(self, name, info, typ, ifcond=None):
790        super().__init__(name, info, typ, False, ifcond)
791
792
793class QAPISchemaCommand(QAPISchemaEntity):
794    meta = 'command'
795
796    def __init__(self, name, info, doc, ifcond, features,
797                 arg_type, ret_type,
798                 gen, success_response, boxed, allow_oob, allow_preconfig,
799                 coroutine):
800        super().__init__(name, info, doc, ifcond, features)
801        assert not arg_type or isinstance(arg_type, str)
802        assert not ret_type or isinstance(ret_type, str)
803        self._arg_type_name = arg_type
804        self.arg_type = None
805        self._ret_type_name = ret_type
806        self.ret_type = None
807        self.gen = gen
808        self.success_response = success_response
809        self.boxed = boxed
810        self.allow_oob = allow_oob
811        self.allow_preconfig = allow_preconfig
812        self.coroutine = coroutine
813
814    def check(self, schema):
815        super().check(schema)
816        if self._arg_type_name:
817            self.arg_type = schema.resolve_type(
818                self._arg_type_name, self.info, "command's 'data'")
819            if not isinstance(self.arg_type, QAPISchemaObjectType):
820                raise QAPISemError(
821                    self.info,
822                    "command's 'data' cannot take %s"
823                    % self.arg_type.describe())
824            if self.arg_type.variants and not self.boxed:
825                raise QAPISemError(
826                    self.info,
827                    "command's 'data' can take %s only with 'boxed': true"
828                    % self.arg_type.describe())
829            self.arg_type.check(schema)
830            if self.arg_type.has_conditional_members() and not self.boxed:
831                raise QAPISemError(
832                    self.info,
833                    "conditional command arguments require 'boxed': true")
834        if self._ret_type_name:
835            self.ret_type = schema.resolve_type(
836                self._ret_type_name, self.info, "command's 'returns'")
837            if self.name not in self.info.pragma.command_returns_exceptions:
838                typ = self.ret_type
839                if isinstance(typ, QAPISchemaArrayType):
840                    typ = self.ret_type.element_type
841                    assert typ
842                if not isinstance(typ, QAPISchemaObjectType):
843                    raise QAPISemError(
844                        self.info,
845                        "command's 'returns' cannot take %s"
846                        % self.ret_type.describe())
847
848    def connect_doc(self, doc=None):
849        super().connect_doc(doc)
850        doc = doc or self.doc
851        if doc:
852            if self.arg_type and self.arg_type.is_implicit():
853                self.arg_type.connect_doc(doc)
854
855    def visit(self, visitor):
856        super().visit(visitor)
857        visitor.visit_command(
858            self.name, self.info, self.ifcond, self.features,
859            self.arg_type, self.ret_type, self.gen, self.success_response,
860            self.boxed, self.allow_oob, self.allow_preconfig,
861            self.coroutine)
862
863
864class QAPISchemaEvent(QAPISchemaEntity):
865    meta = 'event'
866
867    def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
868        super().__init__(name, info, doc, ifcond, features)
869        assert not arg_type or isinstance(arg_type, str)
870        self._arg_type_name = arg_type
871        self.arg_type = None
872        self.boxed = boxed
873
874    def check(self, schema):
875        super().check(schema)
876        if self._arg_type_name:
877            self.arg_type = schema.resolve_type(
878                self._arg_type_name, self.info, "event's 'data'")
879            if not isinstance(self.arg_type, QAPISchemaObjectType):
880                raise QAPISemError(
881                    self.info,
882                    "event's 'data' cannot take %s"
883                    % self.arg_type.describe())
884            if self.arg_type.variants and not self.boxed:
885                raise QAPISemError(
886                    self.info,
887                    "event's 'data' can take %s only with 'boxed': true"
888                    % self.arg_type.describe())
889            self.arg_type.check(schema)
890            if self.arg_type.has_conditional_members() and not self.boxed:
891                raise QAPISemError(
892                    self.info,
893                    "conditional event arguments require 'boxed': true")
894
895    def connect_doc(self, doc=None):
896        super().connect_doc(doc)
897        doc = doc or self.doc
898        if doc:
899            if self.arg_type and self.arg_type.is_implicit():
900                self.arg_type.connect_doc(doc)
901
902    def visit(self, visitor):
903        super().visit(visitor)
904        visitor.visit_event(
905            self.name, self.info, self.ifcond, self.features,
906            self.arg_type, self.boxed)
907
908
909class QAPISchema:
910    def __init__(self, fname):
911        self.fname = fname
912
913        try:
914            parser = QAPISchemaParser(fname)
915        except OSError as err:
916            raise QAPIError(
917                f"can't read schema file '{fname}': {err.strerror}"
918            ) from err
919
920        exprs = check_exprs(parser.exprs)
921        self.docs = parser.docs
922        self._entity_list = []
923        self._entity_dict = {}
924        self._module_dict = OrderedDict()
925        self._schema_dir = os.path.dirname(fname)
926        self._make_module(QAPISchemaModule.BUILTIN_MODULE_NAME)
927        self._make_module(fname)
928        self._predefining = True
929        self._def_predefineds()
930        self._predefining = False
931        self._def_exprs(exprs)
932        self.check()
933
934    def _def_entity(self, ent):
935        # Only the predefined types are allowed to not have info
936        assert ent.info or self._predefining
937        self._entity_list.append(ent)
938        if ent.name is None:
939            return
940        # TODO reject names that differ only in '_' vs. '.'  vs. '-',
941        # because they're liable to clash in generated C.
942        other_ent = self._entity_dict.get(ent.name)
943        if other_ent:
944            if other_ent.info:
945                where = QAPISourceError(other_ent.info, "previous definition")
946                raise QAPISemError(
947                    ent.info,
948                    "'%s' is already defined\n%s" % (ent.name, where))
949            raise QAPISemError(
950                ent.info, "%s is already defined" % other_ent.describe())
951        self._entity_dict[ent.name] = ent
952
953    def lookup_entity(self, name, typ=None):
954        ent = self._entity_dict.get(name)
955        if typ and not isinstance(ent, typ):
956            return None
957        return ent
958
959    def lookup_type(self, name):
960        return self.lookup_entity(name, QAPISchemaType)
961
962    def resolve_type(self, name, info, what):
963        typ = self.lookup_type(name)
964        if not typ:
965            if callable(what):
966                what = what(info)
967            raise QAPISemError(
968                info, "%s uses unknown type '%s'" % (what, name))
969        return typ
970
971    def _module_name(self, fname: str) -> str:
972        if QAPISchemaModule.is_system_module(fname):
973            return fname
974        return os.path.relpath(fname, self._schema_dir)
975
976    def _make_module(self, fname):
977        name = self._module_name(fname)
978        if name not in self._module_dict:
979            self._module_dict[name] = QAPISchemaModule(name)
980        return self._module_dict[name]
981
982    def module_by_fname(self, fname):
983        name = self._module_name(fname)
984        return self._module_dict[name]
985
986    def _def_include(self, expr: QAPIExpression):
987        include = expr['include']
988        assert expr.doc is None
989        self._def_entity(
990            QAPISchemaInclude(self._make_module(include), expr.info))
991
992    def _def_builtin_type(self, name, json_type, c_type):
993        self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
994        # Instantiating only the arrays that are actually used would
995        # be nice, but we can't as long as their generated code
996        # (qapi-builtin-types.[ch]) may be shared by some other
997        # schema.
998        self._make_array_type(name, None)
999
1000    def _def_predefineds(self):
1001        for t in [('str',    'string',  'char' + POINTER_SUFFIX),
1002                  ('number', 'number',  'double'),
1003                  ('int',    'int',     'int64_t'),
1004                  ('int8',   'int',     'int8_t'),
1005                  ('int16',  'int',     'int16_t'),
1006                  ('int32',  'int',     'int32_t'),
1007                  ('int64',  'int',     'int64_t'),
1008                  ('uint8',  'int',     'uint8_t'),
1009                  ('uint16', 'int',     'uint16_t'),
1010                  ('uint32', 'int',     'uint32_t'),
1011                  ('uint64', 'int',     'uint64_t'),
1012                  ('size',   'int',     'uint64_t'),
1013                  ('bool',   'boolean', 'bool'),
1014                  ('any',    'value',   'QObject' + POINTER_SUFFIX),
1015                  ('null',   'null',    'QNull' + POINTER_SUFFIX)]:
1016            self._def_builtin_type(*t)
1017        self.the_empty_object_type = QAPISchemaObjectType(
1018            'q_empty', None, None, None, None, None, [], None)
1019        self._def_entity(self.the_empty_object_type)
1020
1021        qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
1022                  'qbool']
1023        qtype_values = self._make_enum_members(
1024            [{'name': n} for n in qtypes], None)
1025
1026        self._def_entity(QAPISchemaEnumType('QType', None, None, None, None,
1027                                            qtype_values, 'QTYPE'))
1028
1029    def _make_features(self, features, info):
1030        if features is None:
1031            return []
1032        return [QAPISchemaFeature(f['name'], info,
1033                                  QAPISchemaIfCond(f.get('if')))
1034                for f in features]
1035
1036    def _make_enum_member(self, name, ifcond, features, info):
1037        return QAPISchemaEnumMember(name, info,
1038                                    QAPISchemaIfCond(ifcond),
1039                                    self._make_features(features, info))
1040
1041    def _make_enum_members(self, values, info):
1042        return [self._make_enum_member(v['name'], v.get('if'),
1043                                       v.get('features'), info)
1044                for v in values]
1045
1046    def _make_array_type(self, element_type, info):
1047        name = element_type + 'List'    # reserved by check_defn_name_str()
1048        if not self.lookup_type(name):
1049            self._def_entity(QAPISchemaArrayType(name, info, element_type))
1050        return name
1051
1052    def _make_implicit_object_type(self, name, info, ifcond, role, members):
1053        if not members:
1054            return None
1055        # See also QAPISchemaObjectTypeMember.describe()
1056        name = 'q_obj_%s-%s' % (name, role)
1057        typ = self.lookup_entity(name, QAPISchemaObjectType)
1058        if typ:
1059            # The implicit object type has multiple users.  This can
1060            # only be a duplicate definition, which will be flagged
1061            # later.
1062            pass
1063        else:
1064            self._def_entity(QAPISchemaObjectType(
1065                name, info, None, ifcond, None, None, members, None))
1066        return name
1067
1068    def _def_enum_type(self, expr: QAPIExpression):
1069        name = expr['enum']
1070        data = expr['data']
1071        prefix = expr.get('prefix')
1072        ifcond = QAPISchemaIfCond(expr.get('if'))
1073        info = expr.info
1074        features = self._make_features(expr.get('features'), info)
1075        self._def_entity(QAPISchemaEnumType(
1076            name, info, expr.doc, ifcond, features,
1077            self._make_enum_members(data, info), prefix))
1078
1079    def _make_member(self, name, typ, ifcond, features, info):
1080        optional = False
1081        if name.startswith('*'):
1082            name = name[1:]
1083            optional = True
1084        if isinstance(typ, list):
1085            assert len(typ) == 1
1086            typ = self._make_array_type(typ[0], info)
1087        return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond,
1088                                          self._make_features(features, info))
1089
1090    def _make_members(self, data, info):
1091        return [self._make_member(key, value['type'],
1092                                  QAPISchemaIfCond(value.get('if')),
1093                                  value.get('features'), info)
1094                for (key, value) in data.items()]
1095
1096    def _def_struct_type(self, expr: QAPIExpression):
1097        name = expr['struct']
1098        base = expr.get('base')
1099        data = expr['data']
1100        info = expr.info
1101        ifcond = QAPISchemaIfCond(expr.get('if'))
1102        features = self._make_features(expr.get('features'), info)
1103        self._def_entity(QAPISchemaObjectType(
1104            name, info, expr.doc, ifcond, features, base,
1105            self._make_members(data, info),
1106            None))
1107
1108    def _make_variant(self, case, typ, ifcond, info):
1109        if isinstance(typ, list):
1110            assert len(typ) == 1
1111            typ = self._make_array_type(typ[0], info)
1112        return QAPISchemaVariant(case, info, typ, ifcond)
1113
1114    def _def_union_type(self, expr: QAPIExpression):
1115        name = expr['union']
1116        base = expr['base']
1117        tag_name = expr['discriminator']
1118        data = expr['data']
1119        assert isinstance(data, dict)
1120        info = expr.info
1121        ifcond = QAPISchemaIfCond(expr.get('if'))
1122        features = self._make_features(expr.get('features'), info)
1123        if isinstance(base, dict):
1124            base = self._make_implicit_object_type(
1125                name, info, ifcond,
1126                'base', self._make_members(base, info))
1127        variants = [
1128            self._make_variant(key, value['type'],
1129                               QAPISchemaIfCond(value.get('if')),
1130                               info)
1131            for (key, value) in data.items()]
1132        members: List[QAPISchemaObjectTypeMember] = []
1133        self._def_entity(
1134            QAPISchemaObjectType(name, info, expr.doc, ifcond, features,
1135                                 base, members,
1136                                 QAPISchemaVariants(
1137                                     tag_name, info, None, variants)))
1138
1139    def _def_alternate_type(self, expr: QAPIExpression):
1140        name = expr['alternate']
1141        data = expr['data']
1142        assert isinstance(data, dict)
1143        ifcond = QAPISchemaIfCond(expr.get('if'))
1144        info = expr.info
1145        features = self._make_features(expr.get('features'), info)
1146        variants = [
1147            self._make_variant(key, value['type'],
1148                               QAPISchemaIfCond(value.get('if')),
1149                               info)
1150            for (key, value) in data.items()]
1151        tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1152        self._def_entity(
1153            QAPISchemaAlternateType(
1154                name, info, expr.doc, ifcond, features,
1155                QAPISchemaVariants(None, info, tag_member, variants)))
1156
1157    def _def_command(self, expr: QAPIExpression):
1158        name = expr['command']
1159        data = expr.get('data')
1160        rets = expr.get('returns')
1161        gen = expr.get('gen', True)
1162        success_response = expr.get('success-response', True)
1163        boxed = expr.get('boxed', False)
1164        allow_oob = expr.get('allow-oob', False)
1165        allow_preconfig = expr.get('allow-preconfig', False)
1166        coroutine = expr.get('coroutine', False)
1167        ifcond = QAPISchemaIfCond(expr.get('if'))
1168        info = expr.info
1169        features = self._make_features(expr.get('features'), info)
1170        if isinstance(data, OrderedDict):
1171            data = self._make_implicit_object_type(
1172                name, info, ifcond,
1173                'arg', self._make_members(data, info))
1174        if isinstance(rets, list):
1175            assert len(rets) == 1
1176            rets = self._make_array_type(rets[0], info)
1177        self._def_entity(QAPISchemaCommand(name, info, expr.doc, ifcond,
1178                                           features, data, rets,
1179                                           gen, success_response,
1180                                           boxed, allow_oob, allow_preconfig,
1181                                           coroutine))
1182
1183    def _def_event(self, expr: QAPIExpression):
1184        name = expr['event']
1185        data = expr.get('data')
1186        boxed = expr.get('boxed', False)
1187        ifcond = QAPISchemaIfCond(expr.get('if'))
1188        info = expr.info
1189        features = self._make_features(expr.get('features'), info)
1190        if isinstance(data, OrderedDict):
1191            data = self._make_implicit_object_type(
1192                name, info, ifcond,
1193                'arg', self._make_members(data, info))
1194        self._def_entity(QAPISchemaEvent(name, info, expr.doc, ifcond,
1195                                         features, data, boxed))
1196
1197    def _def_exprs(self, exprs):
1198        for expr in exprs:
1199            if 'enum' in expr:
1200                self._def_enum_type(expr)
1201            elif 'struct' in expr:
1202                self._def_struct_type(expr)
1203            elif 'union' in expr:
1204                self._def_union_type(expr)
1205            elif 'alternate' in expr:
1206                self._def_alternate_type(expr)
1207            elif 'command' in expr:
1208                self._def_command(expr)
1209            elif 'event' in expr:
1210                self._def_event(expr)
1211            elif 'include' in expr:
1212                self._def_include(expr)
1213            else:
1214                assert False
1215
1216    def check(self):
1217        for ent in self._entity_list:
1218            ent.check(self)
1219            ent.connect_doc()
1220            ent.check_doc()
1221        for ent in self._entity_list:
1222            ent.set_module(self)
1223
1224    def visit(self, visitor):
1225        visitor.visit_begin(self)
1226        for mod in self._module_dict.values():
1227            mod.visit(visitor)
1228        visitor.visit_end()
1229