xref: /openbmc/qemu/scripts/qapi/schema.py (revision 047f2ca1)
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 (
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 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        QAPISchemaEntity.check(self, 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        assert not self.variants       # not implemented
469        for m in self.members:
470            m.check_clash(info, seen)
471
472    def connect_doc(self, doc=None):
473        super().connect_doc(doc)
474        doc = doc or self.doc
475        if self.base and self.base.is_implicit():
476            self.base.connect_doc(doc)
477        for m in self.local_members:
478            m.connect_doc(doc)
479
480    def is_implicit(self):
481        # See QAPISchema._make_implicit_object_type(), as well as
482        # _def_predefineds()
483        return self.name.startswith('q_')
484
485    def is_empty(self):
486        assert self.members is not None
487        return not self.members and not self.variants
488
489    def c_name(self):
490        assert self.name != 'q_empty'
491        return super().c_name()
492
493    def c_type(self):
494        assert not self.is_implicit()
495        return c_name(self.name) + POINTER_SUFFIX
496
497    def c_unboxed_type(self):
498        return c_name(self.name)
499
500    def json_type(self):
501        return 'object'
502
503    def visit(self, visitor):
504        super().visit(visitor)
505        visitor.visit_object_type(
506            self.name, self.info, self.ifcond, self.features,
507            self.base, self.local_members, self.variants)
508        visitor.visit_object_type_flat(
509            self.name, self.info, self.ifcond, self.features,
510            self.members, self.variants)
511
512
513class QAPISchemaAlternateType(QAPISchemaType):
514    meta = 'alternate'
515
516    def __init__(self, name, info, doc, ifcond, features, variants):
517        super().__init__(name, info, doc, ifcond, features)
518        assert isinstance(variants, QAPISchemaVariants)
519        assert variants.tag_member
520        variants.set_defined_in(name)
521        variants.tag_member.set_defined_in(self.name)
522        self.variants = variants
523
524    def check(self, schema):
525        super().check(schema)
526        self.variants.tag_member.check(schema)
527        # Not calling self.variants.check_clash(), because there's nothing
528        # to clash with
529        self.variants.check(schema, {})
530        # Alternate branch names have no relation to the tag enum values;
531        # so we have to check for potential name collisions ourselves.
532        seen = {}
533        types_seen = {}
534        for v in self.variants.variants:
535            v.check_clash(self.info, seen)
536            qtype = v.type.alternate_qtype()
537            if not qtype:
538                raise QAPISemError(
539                    self.info,
540                    "%s cannot use %s"
541                    % (v.describe(self.info), v.type.describe()))
542            conflicting = set([qtype])
543            if qtype == 'QTYPE_QSTRING':
544                if isinstance(v.type, QAPISchemaEnumType):
545                    for m in v.type.members:
546                        if m.name in ['on', 'off']:
547                            conflicting.add('QTYPE_QBOOL')
548                        if re.match(r'[-+0-9.]', m.name):
549                            # lazy, could be tightened
550                            conflicting.add('QTYPE_QNUM')
551                else:
552                    conflicting.add('QTYPE_QNUM')
553                    conflicting.add('QTYPE_QBOOL')
554            for qt in conflicting:
555                if qt in types_seen:
556                    raise QAPISemError(
557                        self.info,
558                        "%s can't be distinguished from '%s'"
559                        % (v.describe(self.info), types_seen[qt]))
560                types_seen[qt] = v.name
561
562    def connect_doc(self, doc=None):
563        super().connect_doc(doc)
564        doc = doc or self.doc
565        for v in self.variants.variants:
566            v.connect_doc(doc)
567
568    def c_type(self):
569        return c_name(self.name) + POINTER_SUFFIX
570
571    def json_type(self):
572        return 'value'
573
574    def visit(self, visitor):
575        super().visit(visitor)
576        visitor.visit_alternate_type(
577            self.name, self.info, self.ifcond, self.features, self.variants)
578
579
580class QAPISchemaVariants:
581    def __init__(self, tag_name, info, tag_member, variants):
582        # Unions pass tag_name but not tag_member.
583        # Alternates pass tag_member but not tag_name.
584        # After check(), tag_member is always set.
585        assert bool(tag_member) != bool(tag_name)
586        assert (isinstance(tag_name, str) or
587                isinstance(tag_member, QAPISchemaObjectTypeMember))
588        for v in variants:
589            assert isinstance(v, QAPISchemaVariant)
590        self._tag_name = tag_name
591        self.info = info
592        self.tag_member = tag_member
593        self.variants = variants
594
595    def set_defined_in(self, name):
596        for v in self.variants:
597            v.set_defined_in(name)
598
599    def check(self, schema, seen):
600        if self._tag_name:      # union
601            self.tag_member = seen.get(c_name(self._tag_name))
602            base = "'base'"
603            # Pointing to the base type when not implicit would be
604            # nice, but we don't know it here
605            if not self.tag_member or self._tag_name != self.tag_member.name:
606                raise QAPISemError(
607                    self.info,
608                    "discriminator '%s' is not a member of %s"
609                    % (self._tag_name, base))
610            # Here we do:
611            base_type = schema.lookup_type(self.tag_member.defined_in)
612            assert base_type
613            if not base_type.is_implicit():
614                base = "base type '%s'" % self.tag_member.defined_in
615            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
616                raise QAPISemError(
617                    self.info,
618                    "discriminator member '%s' of %s must be of enum type"
619                    % (self._tag_name, base))
620            if self.tag_member.optional:
621                raise QAPISemError(
622                    self.info,
623                    "discriminator member '%s' of %s must not be optional"
624                    % (self._tag_name, base))
625            if self.tag_member.ifcond.is_present():
626                raise QAPISemError(
627                    self.info,
628                    "discriminator member '%s' of %s must not be conditional"
629                    % (self._tag_name, base))
630        else:                   # alternate
631            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
632            assert not self.tag_member.optional
633            assert not self.tag_member.ifcond.is_present()
634        if self._tag_name:      # union
635            # branches that are not explicitly covered get an empty type
636            cases = {v.name for v in self.variants}
637            for m in self.tag_member.type.members:
638                if m.name not in cases:
639                    v = QAPISchemaVariant(m.name, self.info,
640                                          'q_empty', m.ifcond)
641                    v.set_defined_in(self.tag_member.defined_in)
642                    self.variants.append(v)
643        if not self.variants:
644            raise QAPISemError(self.info, "union has no branches")
645        for v in self.variants:
646            v.check(schema)
647            # Union names must match enum values; alternate names are
648            # checked separately. Use 'seen' to tell the two apart.
649            if seen:
650                if v.name not in self.tag_member.type.member_names():
651                    raise QAPISemError(
652                        self.info,
653                        "branch '%s' is not a value of %s"
654                        % (v.name, self.tag_member.type.describe()))
655                if (not isinstance(v.type, QAPISchemaObjectType)
656                        or v.type.variants):
657                    raise QAPISemError(
658                        self.info,
659                        "%s cannot use %s"
660                        % (v.describe(self.info), v.type.describe()))
661                v.type.check(schema)
662
663    def check_clash(self, info, seen):
664        for v in self.variants:
665            # Reset seen map for each variant, since qapi names from one
666            # branch do not affect another branch
667            v.type.check_clash(info, dict(seen))
668
669
670class QAPISchemaMember:
671    """ Represents object members, enum members and features """
672    role = 'member'
673
674    def __init__(self, name, info, ifcond=None):
675        assert isinstance(name, str)
676        self.name = name
677        self.info = info
678        self.ifcond = ifcond or QAPISchemaIfCond()
679        self.defined_in = None
680
681    def set_defined_in(self, name):
682        assert not self.defined_in
683        self.defined_in = name
684
685    def check_clash(self, info, seen):
686        cname = c_name(self.name)
687        if cname in seen:
688            raise QAPISemError(
689                info,
690                "%s collides with %s"
691                % (self.describe(info), seen[cname].describe(info)))
692        seen[cname] = self
693
694    def connect_doc(self, doc):
695        if doc:
696            doc.connect_member(self)
697
698    def describe(self, info):
699        role = self.role
700        defined_in = self.defined_in
701        assert defined_in
702
703        if defined_in.startswith('q_obj_'):
704            # See QAPISchema._make_implicit_object_type() - reverse the
705            # mapping there to create a nice human-readable description
706            defined_in = defined_in[6:]
707            if defined_in.endswith('-arg'):
708                # Implicit type created for a command's dict 'data'
709                assert role == 'member'
710                role = 'parameter'
711            elif defined_in.endswith('-base'):
712                # Implicit type created for a union's dict 'base'
713                role = 'base ' + role
714            else:
715                assert False
716        elif defined_in != info.defn_name:
717            return "%s '%s' of type '%s'" % (role, self.name, defined_in)
718        return "%s '%s'" % (role, self.name)
719
720
721class QAPISchemaEnumMember(QAPISchemaMember):
722    role = 'value'
723
724    def __init__(self, name, info, ifcond=None, features=None):
725        super().__init__(name, info, ifcond)
726        for f in features or []:
727            assert isinstance(f, QAPISchemaFeature)
728            f.set_defined_in(name)
729        self.features = features or []
730
731    def connect_doc(self, doc):
732        super().connect_doc(doc)
733        if doc:
734            for f in self.features:
735                doc.connect_feature(f)
736
737
738class QAPISchemaFeature(QAPISchemaMember):
739    role = 'feature'
740
741    def is_special(self):
742        return self.name in ('deprecated', 'unstable')
743
744
745class QAPISchemaObjectTypeMember(QAPISchemaMember):
746    def __init__(self, name, info, typ, optional, ifcond=None, features=None):
747        super().__init__(name, info, ifcond)
748        assert isinstance(typ, str)
749        assert isinstance(optional, bool)
750        for f in features or []:
751            assert isinstance(f, QAPISchemaFeature)
752            f.set_defined_in(name)
753        self._type_name = typ
754        self.type = None
755        self.optional = optional
756        self.features = features or []
757
758    def need_has(self):
759        assert self.type
760        # Temporary hack to support dropping the has_FOO in reviewable chunks
761        opt_out = [
762            'qapi/replay.json',
763            'qapi/rocker.json',
764            'qapi/run-state.json',
765            'qapi/stats.json',
766            'qapi/tpm.json',
767            'qapi/transaction.json',
768            'qapi/ui.json',
769            'qapi/virtio.json',
770            'qga/qapi-schema.json']
771        if self.info and any(self.info.fname.endswith(mod)
772                             for mod in opt_out):
773            return self.optional
774        # End of temporary hack
775        return self.optional and self.type.need_has_if_optional()
776
777    def check(self, schema):
778        assert self.defined_in
779        self.type = schema.resolve_type(self._type_name, self.info,
780                                        self.describe)
781        seen = {}
782        for f in self.features:
783            f.check_clash(self.info, seen)
784
785    def connect_doc(self, doc):
786        super().connect_doc(doc)
787        if doc:
788            for f in self.features:
789                doc.connect_feature(f)
790
791
792class QAPISchemaVariant(QAPISchemaObjectTypeMember):
793    role = 'branch'
794
795    def __init__(self, name, info, typ, ifcond=None):
796        super().__init__(name, info, typ, False, ifcond)
797
798
799class QAPISchemaCommand(QAPISchemaEntity):
800    meta = 'command'
801
802    def __init__(self, name, info, doc, ifcond, features,
803                 arg_type, ret_type,
804                 gen, success_response, boxed, allow_oob, allow_preconfig,
805                 coroutine):
806        super().__init__(name, info, doc, ifcond, features)
807        assert not arg_type or isinstance(arg_type, str)
808        assert not ret_type or isinstance(ret_type, str)
809        self._arg_type_name = arg_type
810        self.arg_type = None
811        self._ret_type_name = ret_type
812        self.ret_type = None
813        self.gen = gen
814        self.success_response = success_response
815        self.boxed = boxed
816        self.allow_oob = allow_oob
817        self.allow_preconfig = allow_preconfig
818        self.coroutine = coroutine
819
820    def check(self, schema):
821        super().check(schema)
822        if self._arg_type_name:
823            self.arg_type = schema.resolve_type(
824                self._arg_type_name, self.info, "command's 'data'")
825            if not isinstance(self.arg_type, QAPISchemaObjectType):
826                raise QAPISemError(
827                    self.info,
828                    "command's 'data' cannot take %s"
829                    % self.arg_type.describe())
830            if self.arg_type.variants and not self.boxed:
831                raise QAPISemError(
832                    self.info,
833                    "command's 'data' can take %s only with 'boxed': true"
834                    % self.arg_type.describe())
835        if self._ret_type_name:
836            self.ret_type = schema.resolve_type(
837                self._ret_type_name, self.info, "command's 'returns'")
838            if self.name not in self.info.pragma.command_returns_exceptions:
839                typ = self.ret_type
840                if isinstance(typ, QAPISchemaArrayType):
841                    typ = self.ret_type.element_type
842                    assert typ
843                if not isinstance(typ, QAPISchemaObjectType):
844                    raise QAPISemError(
845                        self.info,
846                        "command's 'returns' cannot take %s"
847                        % self.ret_type.describe())
848
849    def connect_doc(self, doc=None):
850        super().connect_doc(doc)
851        doc = doc or self.doc
852        if doc:
853            if self.arg_type and self.arg_type.is_implicit():
854                self.arg_type.connect_doc(doc)
855
856    def visit(self, visitor):
857        super().visit(visitor)
858        visitor.visit_command(
859            self.name, self.info, self.ifcond, self.features,
860            self.arg_type, self.ret_type, self.gen, self.success_response,
861            self.boxed, self.allow_oob, self.allow_preconfig,
862            self.coroutine)
863
864
865class QAPISchemaEvent(QAPISchemaEntity):
866    meta = 'event'
867
868    def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
869        super().__init__(name, info, doc, ifcond, features)
870        assert not arg_type or isinstance(arg_type, str)
871        self._arg_type_name = arg_type
872        self.arg_type = None
873        self.boxed = boxed
874
875    def check(self, schema):
876        super().check(schema)
877        if self._arg_type_name:
878            self.arg_type = schema.resolve_type(
879                self._arg_type_name, self.info, "event's 'data'")
880            if not isinstance(self.arg_type, QAPISchemaObjectType):
881                raise QAPISemError(
882                    self.info,
883                    "event's 'data' cannot take %s"
884                    % self.arg_type.describe())
885            if self.arg_type.variants and not self.boxed:
886                raise QAPISemError(
887                    self.info,
888                    "event's 'data' can take %s only with 'boxed': true"
889                    % self.arg_type.describe())
890
891    def connect_doc(self, doc=None):
892        super().connect_doc(doc)
893        doc = doc or self.doc
894        if doc:
895            if self.arg_type and self.arg_type.is_implicit():
896                self.arg_type.connect_doc(doc)
897
898    def visit(self, visitor):
899        super().visit(visitor)
900        visitor.visit_event(
901            self.name, self.info, self.ifcond, self.features,
902            self.arg_type, self.boxed)
903
904
905class QAPISchema:
906    def __init__(self, fname):
907        self.fname = fname
908
909        try:
910            parser = QAPISchemaParser(fname)
911        except OSError as err:
912            raise QAPIError(
913                f"can't read schema file '{fname}': {err.strerror}"
914            ) from err
915
916        exprs = check_exprs(parser.exprs)
917        self.docs = parser.docs
918        self._entity_list = []
919        self._entity_dict = {}
920        self._module_dict = OrderedDict()
921        self._schema_dir = os.path.dirname(fname)
922        self._make_module(QAPISchemaModule.BUILTIN_MODULE_NAME)
923        self._make_module(fname)
924        self._predefining = True
925        self._def_predefineds()
926        self._predefining = False
927        self._def_exprs(exprs)
928        self.check()
929
930    def _def_entity(self, ent):
931        # Only the predefined types are allowed to not have info
932        assert ent.info or self._predefining
933        self._entity_list.append(ent)
934        if ent.name is None:
935            return
936        # TODO reject names that differ only in '_' vs. '.'  vs. '-',
937        # because they're liable to clash in generated C.
938        other_ent = self._entity_dict.get(ent.name)
939        if other_ent:
940            if other_ent.info:
941                where = QAPISourceError(other_ent.info, "previous definition")
942                raise QAPISemError(
943                    ent.info,
944                    "'%s' is already defined\n%s" % (ent.name, where))
945            raise QAPISemError(
946                ent.info, "%s is already defined" % other_ent.describe())
947        self._entity_dict[ent.name] = ent
948
949    def lookup_entity(self, name, typ=None):
950        ent = self._entity_dict.get(name)
951        if typ and not isinstance(ent, typ):
952            return None
953        return ent
954
955    def lookup_type(self, name):
956        return self.lookup_entity(name, QAPISchemaType)
957
958    def resolve_type(self, name, info, what):
959        typ = self.lookup_type(name)
960        if not typ:
961            if callable(what):
962                what = what(info)
963            raise QAPISemError(
964                info, "%s uses unknown type '%s'" % (what, name))
965        return typ
966
967    def _module_name(self, fname: str) -> str:
968        if QAPISchemaModule.is_system_module(fname):
969            return fname
970        return os.path.relpath(fname, self._schema_dir)
971
972    def _make_module(self, fname):
973        name = self._module_name(fname)
974        if name not in self._module_dict:
975            self._module_dict[name] = QAPISchemaModule(name)
976        return self._module_dict[name]
977
978    def module_by_fname(self, fname):
979        name = self._module_name(fname)
980        return self._module_dict[name]
981
982    def _def_include(self, expr, info, doc):
983        include = expr['include']
984        assert doc is None
985        self._def_entity(QAPISchemaInclude(self._make_module(include), info))
986
987    def _def_builtin_type(self, name, json_type, c_type):
988        self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
989        # Instantiating only the arrays that are actually used would
990        # be nice, but we can't as long as their generated code
991        # (qapi-builtin-types.[ch]) may be shared by some other
992        # schema.
993        self._make_array_type(name, None)
994
995    def _def_predefineds(self):
996        for t in [('str',    'string',  'char' + POINTER_SUFFIX),
997                  ('number', 'number',  'double'),
998                  ('int',    'int',     'int64_t'),
999                  ('int8',   'int',     'int8_t'),
1000                  ('int16',  'int',     'int16_t'),
1001                  ('int32',  'int',     'int32_t'),
1002                  ('int64',  'int',     'int64_t'),
1003                  ('uint8',  'int',     'uint8_t'),
1004                  ('uint16', 'int',     'uint16_t'),
1005                  ('uint32', 'int',     'uint32_t'),
1006                  ('uint64', 'int',     'uint64_t'),
1007                  ('size',   'int',     'uint64_t'),
1008                  ('bool',   'boolean', 'bool'),
1009                  ('any',    'value',   'QObject' + POINTER_SUFFIX),
1010                  ('null',   'null',    'QNull' + POINTER_SUFFIX)]:
1011            self._def_builtin_type(*t)
1012        self.the_empty_object_type = QAPISchemaObjectType(
1013            'q_empty', None, None, None, None, None, [], None)
1014        self._def_entity(self.the_empty_object_type)
1015
1016        qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
1017                  'qbool']
1018        qtype_values = self._make_enum_members(
1019            [{'name': n} for n in qtypes], None)
1020
1021        self._def_entity(QAPISchemaEnumType('QType', None, None, None, None,
1022                                            qtype_values, 'QTYPE'))
1023
1024    def _make_features(self, features, info):
1025        if features is None:
1026            return []
1027        return [QAPISchemaFeature(f['name'], info,
1028                                  QAPISchemaIfCond(f.get('if')))
1029                for f in features]
1030
1031    def _make_enum_member(self, name, ifcond, features, info):
1032        return QAPISchemaEnumMember(name, info,
1033                                    QAPISchemaIfCond(ifcond),
1034                                    self._make_features(features, info))
1035
1036    def _make_enum_members(self, values, info):
1037        return [self._make_enum_member(v['name'], v.get('if'),
1038                                       v.get('features'), info)
1039                for v in values]
1040
1041    def _make_array_type(self, element_type, info):
1042        name = element_type + 'List'    # reserved by check_defn_name_str()
1043        if not self.lookup_type(name):
1044            self._def_entity(QAPISchemaArrayType(name, info, element_type))
1045        return name
1046
1047    def _make_implicit_object_type(self, name, info, ifcond, role, members):
1048        if not members:
1049            return None
1050        # See also QAPISchemaObjectTypeMember.describe()
1051        name = 'q_obj_%s-%s' % (name, role)
1052        typ = self.lookup_entity(name, QAPISchemaObjectType)
1053        if typ:
1054            # The implicit object type has multiple users.  This can
1055            # only be a duplicate definition, which will be flagged
1056            # later.
1057            pass
1058        else:
1059            self._def_entity(QAPISchemaObjectType(
1060                name, info, None, ifcond, None, None, members, None))
1061        return name
1062
1063    def _def_enum_type(self, expr, info, doc):
1064        name = expr['enum']
1065        data = expr['data']
1066        prefix = expr.get('prefix')
1067        ifcond = QAPISchemaIfCond(expr.get('if'))
1068        features = self._make_features(expr.get('features'), info)
1069        self._def_entity(QAPISchemaEnumType(
1070            name, info, doc, ifcond, features,
1071            self._make_enum_members(data, info), prefix))
1072
1073    def _make_member(self, name, typ, ifcond, features, info):
1074        optional = False
1075        if name.startswith('*'):
1076            name = name[1:]
1077            optional = True
1078        if isinstance(typ, list):
1079            assert len(typ) == 1
1080            typ = self._make_array_type(typ[0], info)
1081        return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond,
1082                                          self._make_features(features, info))
1083
1084    def _make_members(self, data, info):
1085        return [self._make_member(key, value['type'],
1086                                  QAPISchemaIfCond(value.get('if')),
1087                                  value.get('features'), info)
1088                for (key, value) in data.items()]
1089
1090    def _def_struct_type(self, expr, info, doc):
1091        name = expr['struct']
1092        base = expr.get('base')
1093        data = expr['data']
1094        ifcond = QAPISchemaIfCond(expr.get('if'))
1095        features = self._make_features(expr.get('features'), info)
1096        self._def_entity(QAPISchemaObjectType(
1097            name, info, doc, ifcond, features, base,
1098            self._make_members(data, info),
1099            None))
1100
1101    def _make_variant(self, case, typ, ifcond, info):
1102        if isinstance(typ, list):
1103            assert len(typ) == 1
1104            typ = self._make_array_type(typ[0], info)
1105        return QAPISchemaVariant(case, info, typ, ifcond)
1106
1107    def _def_union_type(self, expr, info, doc):
1108        name = expr['union']
1109        base = expr['base']
1110        tag_name = expr['discriminator']
1111        data = expr['data']
1112        ifcond = QAPISchemaIfCond(expr.get('if'))
1113        features = self._make_features(expr.get('features'), info)
1114        if isinstance(base, dict):
1115            base = self._make_implicit_object_type(
1116                name, info, ifcond,
1117                'base', self._make_members(base, info))
1118        variants = [
1119            self._make_variant(key, value['type'],
1120                               QAPISchemaIfCond(value.get('if')),
1121                               info)
1122            for (key, value) in data.items()]
1123        members = []
1124        self._def_entity(
1125            QAPISchemaObjectType(name, info, doc, ifcond, features,
1126                                 base, members,
1127                                 QAPISchemaVariants(
1128                                     tag_name, info, None, variants)))
1129
1130    def _def_alternate_type(self, expr, info, doc):
1131        name = expr['alternate']
1132        data = expr['data']
1133        ifcond = QAPISchemaIfCond(expr.get('if'))
1134        features = self._make_features(expr.get('features'), info)
1135        variants = [
1136            self._make_variant(key, value['type'],
1137                               QAPISchemaIfCond(value.get('if')),
1138                               info)
1139            for (key, value) in data.items()]
1140        tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1141        self._def_entity(
1142            QAPISchemaAlternateType(name, info, doc, ifcond, features,
1143                                    QAPISchemaVariants(
1144                                        None, info, tag_member, variants)))
1145
1146    def _def_command(self, expr, info, doc):
1147        name = expr['command']
1148        data = expr.get('data')
1149        rets = expr.get('returns')
1150        gen = expr.get('gen', True)
1151        success_response = expr.get('success-response', True)
1152        boxed = expr.get('boxed', False)
1153        allow_oob = expr.get('allow-oob', False)
1154        allow_preconfig = expr.get('allow-preconfig', False)
1155        coroutine = expr.get('coroutine', False)
1156        ifcond = QAPISchemaIfCond(expr.get('if'))
1157        features = self._make_features(expr.get('features'), info)
1158        if isinstance(data, OrderedDict):
1159            data = self._make_implicit_object_type(
1160                name, info, ifcond,
1161                'arg', self._make_members(data, info))
1162        if isinstance(rets, list):
1163            assert len(rets) == 1
1164            rets = self._make_array_type(rets[0], info)
1165        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, features,
1166                                           data, rets,
1167                                           gen, success_response,
1168                                           boxed, allow_oob, allow_preconfig,
1169                                           coroutine))
1170
1171    def _def_event(self, expr, info, doc):
1172        name = expr['event']
1173        data = expr.get('data')
1174        boxed = expr.get('boxed', False)
1175        ifcond = QAPISchemaIfCond(expr.get('if'))
1176        features = self._make_features(expr.get('features'), info)
1177        if isinstance(data, OrderedDict):
1178            data = self._make_implicit_object_type(
1179                name, info, ifcond,
1180                'arg', self._make_members(data, info))
1181        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, features,
1182                                         data, boxed))
1183
1184    def _def_exprs(self, exprs):
1185        for expr_elem in exprs:
1186            expr = expr_elem['expr']
1187            info = expr_elem['info']
1188            doc = expr_elem.get('doc')
1189            if 'enum' in expr:
1190                self._def_enum_type(expr, info, doc)
1191            elif 'struct' in expr:
1192                self._def_struct_type(expr, info, doc)
1193            elif 'union' in expr:
1194                self._def_union_type(expr, info, doc)
1195            elif 'alternate' in expr:
1196                self._def_alternate_type(expr, info, doc)
1197            elif 'command' in expr:
1198                self._def_command(expr, info, doc)
1199            elif 'event' in expr:
1200                self._def_event(expr, info, doc)
1201            elif 'include' in expr:
1202                self._def_include(expr, info, doc)
1203            else:
1204                assert False
1205
1206    def check(self):
1207        for ent in self._entity_list:
1208            ent.check(self)
1209            ent.connect_doc()
1210            ent.check_doc()
1211        for ent in self._entity_list:
1212            ent.set_module(self)
1213
1214    def visit(self, visitor):
1215        visitor.visit_begin(self)
1216        for mod in self._module_dict.values():
1217            mod.visit(visitor)
1218        visitor.visit_end()
1219