xref: /openbmc/qemu/scripts/qapi/schema.py (revision b91a0fa7)
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            'object':  'QTYPE_QDICT'
247        }
248        return json2qtype.get(self.json_type())
249
250    def doc_type(self):
251        if self.is_implicit():
252            return None
253        return self.name
254
255    def check(self, schema):
256        QAPISchemaEntity.check(self, schema)
257        for feat in self.features:
258            if feat.is_special():
259                raise QAPISemError(
260                    self.info,
261                    f"feature '{feat.name}' is not supported for types")
262
263    def describe(self):
264        assert self.meta
265        return "%s type '%s'" % (self.meta, self.name)
266
267
268class QAPISchemaBuiltinType(QAPISchemaType):
269    meta = 'built-in'
270
271    def __init__(self, name, json_type, c_type):
272        super().__init__(name, None, None)
273        assert not c_type or isinstance(c_type, str)
274        assert json_type in ('string', 'number', 'int', 'boolean', 'null',
275                             'value')
276        self._json_type_name = json_type
277        self._c_type_name = c_type
278
279    def c_name(self):
280        return self.name
281
282    def c_type(self):
283        return self._c_type_name
284
285    def c_param_type(self):
286        if self.name == 'str':
287            return 'const ' + self._c_type_name
288        return self._c_type_name
289
290    def json_type(self):
291        return self._json_type_name
292
293    def doc_type(self):
294        return self.json_type()
295
296    def visit(self, visitor):
297        super().visit(visitor)
298        visitor.visit_builtin_type(self.name, self.info, self.json_type())
299
300
301class QAPISchemaEnumType(QAPISchemaType):
302    meta = 'enum'
303
304    def __init__(self, name, info, doc, ifcond, features, members, prefix):
305        super().__init__(name, info, doc, ifcond, features)
306        for m in members:
307            assert isinstance(m, QAPISchemaEnumMember)
308            m.set_defined_in(name)
309        assert prefix is None or isinstance(prefix, str)
310        self.members = members
311        self.prefix = prefix
312
313    def check(self, schema):
314        super().check(schema)
315        seen = {}
316        for m in self.members:
317            m.check_clash(self.info, seen)
318
319    def connect_doc(self, doc=None):
320        super().connect_doc(doc)
321        doc = doc or self.doc
322        for m in self.members:
323            m.connect_doc(doc)
324
325    def is_implicit(self):
326        # See QAPISchema._def_predefineds()
327        return self.name == 'QType'
328
329    def c_type(self):
330        return c_name(self.name)
331
332    def member_names(self):
333        return [m.name for m in self.members]
334
335    def json_type(self):
336        return 'string'
337
338    def visit(self, visitor):
339        super().visit(visitor)
340        visitor.visit_enum_type(
341            self.name, self.info, self.ifcond, self.features,
342            self.members, self.prefix)
343
344
345class QAPISchemaArrayType(QAPISchemaType):
346    meta = 'array'
347
348    def __init__(self, name, info, element_type):
349        super().__init__(name, info, None)
350        assert isinstance(element_type, str)
351        self._element_type_name = element_type
352        self.element_type = None
353
354    def check(self, schema):
355        super().check(schema)
356        self.element_type = schema.resolve_type(
357            self._element_type_name, self.info,
358            self.info and self.info.defn_meta)
359        assert not isinstance(self.element_type, QAPISchemaArrayType)
360
361    def set_module(self, schema):
362        self._set_module(schema, self.element_type.info)
363
364    @property
365    def ifcond(self):
366        assert self._checked
367        return self.element_type.ifcond
368
369    def is_implicit(self):
370        return True
371
372    def c_type(self):
373        return c_name(self.name) + POINTER_SUFFIX
374
375    def json_type(self):
376        return 'array'
377
378    def doc_type(self):
379        elt_doc_type = self.element_type.doc_type()
380        if not elt_doc_type:
381            return None
382        return 'array of ' + elt_doc_type
383
384    def visit(self, visitor):
385        super().visit(visitor)
386        visitor.visit_array_type(self.name, self.info, self.ifcond,
387                                 self.element_type)
388
389    def describe(self):
390        assert self.meta
391        return "%s type ['%s']" % (self.meta, self._element_type_name)
392
393
394class QAPISchemaObjectType(QAPISchemaType):
395    def __init__(self, name, info, doc, ifcond, features,
396                 base, local_members, variants):
397        # struct has local_members, optional base, and no variants
398        # union has base, variants, and no local_members
399        super().__init__(name, info, doc, ifcond, features)
400        self.meta = 'union' if variants else 'struct'
401        assert base is None or isinstance(base, str)
402        for m in local_members:
403            assert isinstance(m, QAPISchemaObjectTypeMember)
404            m.set_defined_in(name)
405        if variants is not None:
406            assert isinstance(variants, QAPISchemaVariants)
407            variants.set_defined_in(name)
408        self._base_name = base
409        self.base = None
410        self.local_members = local_members
411        self.variants = variants
412        self.members = None
413
414    def check(self, schema):
415        # This calls another type T's .check() exactly when the C
416        # struct emitted by gen_object() contains that T's C struct
417        # (pointers don't count).
418        if self.members is not None:
419            # A previous .check() completed: nothing to do
420            return
421        if self._checked:
422            # Recursed: C struct contains itself
423            raise QAPISemError(self.info,
424                               "object %s contains itself" % self.name)
425
426        super().check(schema)
427        assert self._checked and self.members is None
428
429        seen = OrderedDict()
430        if self._base_name:
431            self.base = schema.resolve_type(self._base_name, self.info,
432                                            "'base'")
433            if (not isinstance(self.base, QAPISchemaObjectType)
434                    or self.base.variants):
435                raise QAPISemError(
436                    self.info,
437                    "'base' requires a struct type, %s isn't"
438                    % self.base.describe())
439            self.base.check(schema)
440            self.base.check_clash(self.info, seen)
441        for m in self.local_members:
442            m.check(schema)
443            m.check_clash(self.info, seen)
444        members = seen.values()
445
446        if self.variants:
447            self.variants.check(schema, seen)
448            self.variants.check_clash(self.info, seen)
449
450        self.members = members  # mark completed
451
452    # Check that the members of this type do not cause duplicate JSON members,
453    # and update seen to track the members seen so far. Report any errors
454    # on behalf of info, which is not necessarily self.info
455    def check_clash(self, info, seen):
456        assert self._checked
457        assert not self.variants       # not implemented
458        for m in self.members:
459            m.check_clash(info, seen)
460
461    def connect_doc(self, doc=None):
462        super().connect_doc(doc)
463        doc = doc or self.doc
464        if self.base and self.base.is_implicit():
465            self.base.connect_doc(doc)
466        for m in self.local_members:
467            m.connect_doc(doc)
468
469    def is_implicit(self):
470        # See QAPISchema._make_implicit_object_type(), as well as
471        # _def_predefineds()
472        return self.name.startswith('q_')
473
474    def is_empty(self):
475        assert self.members is not None
476        return not self.members and not self.variants
477
478    def c_name(self):
479        assert self.name != 'q_empty'
480        return super().c_name()
481
482    def c_type(self):
483        assert not self.is_implicit()
484        return c_name(self.name) + POINTER_SUFFIX
485
486    def c_unboxed_type(self):
487        return c_name(self.name)
488
489    def json_type(self):
490        return 'object'
491
492    def visit(self, visitor):
493        super().visit(visitor)
494        visitor.visit_object_type(
495            self.name, self.info, self.ifcond, self.features,
496            self.base, self.local_members, self.variants)
497        visitor.visit_object_type_flat(
498            self.name, self.info, self.ifcond, self.features,
499            self.members, self.variants)
500
501
502class QAPISchemaAlternateType(QAPISchemaType):
503    meta = 'alternate'
504
505    def __init__(self, name, info, doc, ifcond, features, variants):
506        super().__init__(name, info, doc, ifcond, features)
507        assert isinstance(variants, QAPISchemaVariants)
508        assert variants.tag_member
509        variants.set_defined_in(name)
510        variants.tag_member.set_defined_in(self.name)
511        self.variants = variants
512
513    def check(self, schema):
514        super().check(schema)
515        self.variants.tag_member.check(schema)
516        # Not calling self.variants.check_clash(), because there's nothing
517        # to clash with
518        self.variants.check(schema, {})
519        # Alternate branch names have no relation to the tag enum values;
520        # so we have to check for potential name collisions ourselves.
521        seen = {}
522        types_seen = {}
523        for v in self.variants.variants:
524            v.check_clash(self.info, seen)
525            qtype = v.type.alternate_qtype()
526            if not qtype:
527                raise QAPISemError(
528                    self.info,
529                    "%s cannot use %s"
530                    % (v.describe(self.info), v.type.describe()))
531            conflicting = set([qtype])
532            if qtype == 'QTYPE_QSTRING':
533                if isinstance(v.type, QAPISchemaEnumType):
534                    for m in v.type.members:
535                        if m.name in ['on', 'off']:
536                            conflicting.add('QTYPE_QBOOL')
537                        if re.match(r'[-+0-9.]', m.name):
538                            # lazy, could be tightened
539                            conflicting.add('QTYPE_QNUM')
540                else:
541                    conflicting.add('QTYPE_QNUM')
542                    conflicting.add('QTYPE_QBOOL')
543            for qt in conflicting:
544                if qt in types_seen:
545                    raise QAPISemError(
546                        self.info,
547                        "%s can't be distinguished from '%s'"
548                        % (v.describe(self.info), types_seen[qt]))
549                types_seen[qt] = v.name
550
551    def connect_doc(self, doc=None):
552        super().connect_doc(doc)
553        doc = doc or self.doc
554        for v in self.variants.variants:
555            v.connect_doc(doc)
556
557    def c_type(self):
558        return c_name(self.name) + POINTER_SUFFIX
559
560    def json_type(self):
561        return 'value'
562
563    def visit(self, visitor):
564        super().visit(visitor)
565        visitor.visit_alternate_type(
566            self.name, self.info, self.ifcond, self.features, self.variants)
567
568
569class QAPISchemaVariants:
570    def __init__(self, tag_name, info, tag_member, variants):
571        # Unions pass tag_name but not tag_member.
572        # Alternates pass tag_member but not tag_name.
573        # After check(), tag_member is always set.
574        assert bool(tag_member) != bool(tag_name)
575        assert (isinstance(tag_name, str) or
576                isinstance(tag_member, QAPISchemaObjectTypeMember))
577        for v in variants:
578            assert isinstance(v, QAPISchemaVariant)
579        self._tag_name = tag_name
580        self.info = info
581        self.tag_member = tag_member
582        self.variants = variants
583
584    def set_defined_in(self, name):
585        for v in self.variants:
586            v.set_defined_in(name)
587
588    def check(self, schema, seen):
589        if self._tag_name:      # union
590            self.tag_member = seen.get(c_name(self._tag_name))
591            base = "'base'"
592            # Pointing to the base type when not implicit would be
593            # nice, but we don't know it here
594            if not self.tag_member or self._tag_name != self.tag_member.name:
595                raise QAPISemError(
596                    self.info,
597                    "discriminator '%s' is not a member of %s"
598                    % (self._tag_name, base))
599            # Here we do:
600            base_type = schema.lookup_type(self.tag_member.defined_in)
601            assert base_type
602            if not base_type.is_implicit():
603                base = "base type '%s'" % self.tag_member.defined_in
604            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
605                raise QAPISemError(
606                    self.info,
607                    "discriminator member '%s' of %s must be of enum type"
608                    % (self._tag_name, base))
609            if self.tag_member.optional:
610                raise QAPISemError(
611                    self.info,
612                    "discriminator member '%s' of %s must not be optional"
613                    % (self._tag_name, base))
614            if self.tag_member.ifcond.is_present():
615                raise QAPISemError(
616                    self.info,
617                    "discriminator member '%s' of %s must not be conditional"
618                    % (self._tag_name, base))
619        else:                   # alternate
620            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
621            assert not self.tag_member.optional
622            assert not self.tag_member.ifcond.is_present()
623        if self._tag_name:      # union
624            # branches that are not explicitly covered get an empty type
625            cases = {v.name for v in self.variants}
626            for m in self.tag_member.type.members:
627                if m.name not in cases:
628                    v = QAPISchemaVariant(m.name, self.info,
629                                          'q_empty', m.ifcond)
630                    v.set_defined_in(self.tag_member.defined_in)
631                    self.variants.append(v)
632        if not self.variants:
633            raise QAPISemError(self.info, "union has no branches")
634        for v in self.variants:
635            v.check(schema)
636            # Union names must match enum values; alternate names are
637            # checked separately. Use 'seen' to tell the two apart.
638            if seen:
639                if v.name not in self.tag_member.type.member_names():
640                    raise QAPISemError(
641                        self.info,
642                        "branch '%s' is not a value of %s"
643                        % (v.name, self.tag_member.type.describe()))
644                if (not isinstance(v.type, QAPISchemaObjectType)
645                        or v.type.variants):
646                    raise QAPISemError(
647                        self.info,
648                        "%s cannot use %s"
649                        % (v.describe(self.info), v.type.describe()))
650                v.type.check(schema)
651
652    def check_clash(self, info, seen):
653        for v in self.variants:
654            # Reset seen map for each variant, since qapi names from one
655            # branch do not affect another branch
656            v.type.check_clash(info, dict(seen))
657
658
659class QAPISchemaMember:
660    """ Represents object members, enum members and features """
661    role = 'member'
662
663    def __init__(self, name, info, ifcond=None):
664        assert isinstance(name, str)
665        self.name = name
666        self.info = info
667        self.ifcond = ifcond or QAPISchemaIfCond()
668        self.defined_in = None
669
670    def set_defined_in(self, name):
671        assert not self.defined_in
672        self.defined_in = name
673
674    def check_clash(self, info, seen):
675        cname = c_name(self.name)
676        if cname in seen:
677            raise QAPISemError(
678                info,
679                "%s collides with %s"
680                % (self.describe(info), seen[cname].describe(info)))
681        seen[cname] = self
682
683    def connect_doc(self, doc):
684        if doc:
685            doc.connect_member(self)
686
687    def describe(self, info):
688        role = self.role
689        defined_in = self.defined_in
690        assert defined_in
691
692        if defined_in.startswith('q_obj_'):
693            # See QAPISchema._make_implicit_object_type() - reverse the
694            # mapping there to create a nice human-readable description
695            defined_in = defined_in[6:]
696            if defined_in.endswith('-arg'):
697                # Implicit type created for a command's dict 'data'
698                assert role == 'member'
699                role = 'parameter'
700            elif defined_in.endswith('-base'):
701                # Implicit type created for a union's dict 'base'
702                role = 'base ' + role
703            else:
704                assert False
705        elif defined_in != info.defn_name:
706            return "%s '%s' of type '%s'" % (role, self.name, defined_in)
707        return "%s '%s'" % (role, self.name)
708
709
710class QAPISchemaEnumMember(QAPISchemaMember):
711    role = 'value'
712
713    def __init__(self, name, info, ifcond=None, features=None):
714        super().__init__(name, info, ifcond)
715        for f in features or []:
716            assert isinstance(f, QAPISchemaFeature)
717            f.set_defined_in(name)
718        self.features = features or []
719
720    def connect_doc(self, doc):
721        super().connect_doc(doc)
722        if doc:
723            for f in self.features:
724                doc.connect_feature(f)
725
726
727class QAPISchemaFeature(QAPISchemaMember):
728    role = 'feature'
729
730    def is_special(self):
731        return self.name in ('deprecated', 'unstable')
732
733
734class QAPISchemaObjectTypeMember(QAPISchemaMember):
735    def __init__(self, name, info, typ, optional, ifcond=None, features=None):
736        super().__init__(name, info, ifcond)
737        assert isinstance(typ, str)
738        assert isinstance(optional, bool)
739        for f in features or []:
740            assert isinstance(f, QAPISchemaFeature)
741            f.set_defined_in(name)
742        self._type_name = typ
743        self.type = None
744        self.optional = optional
745        self.features = features or []
746
747    def check(self, schema):
748        assert self.defined_in
749        self.type = schema.resolve_type(self._type_name, self.info,
750                                        self.describe)
751        seen = {}
752        for f in self.features:
753            f.check_clash(self.info, seen)
754
755    def connect_doc(self, doc):
756        super().connect_doc(doc)
757        if doc:
758            for f in self.features:
759                doc.connect_feature(f)
760
761
762class QAPISchemaVariant(QAPISchemaObjectTypeMember):
763    role = 'branch'
764
765    def __init__(self, name, info, typ, ifcond=None):
766        super().__init__(name, info, typ, False, ifcond)
767
768
769class QAPISchemaCommand(QAPISchemaEntity):
770    meta = 'command'
771
772    def __init__(self, name, info, doc, ifcond, features,
773                 arg_type, ret_type,
774                 gen, success_response, boxed, allow_oob, allow_preconfig,
775                 coroutine):
776        super().__init__(name, info, doc, ifcond, features)
777        assert not arg_type or isinstance(arg_type, str)
778        assert not ret_type or isinstance(ret_type, str)
779        self._arg_type_name = arg_type
780        self.arg_type = None
781        self._ret_type_name = ret_type
782        self.ret_type = None
783        self.gen = gen
784        self.success_response = success_response
785        self.boxed = boxed
786        self.allow_oob = allow_oob
787        self.allow_preconfig = allow_preconfig
788        self.coroutine = coroutine
789
790    def check(self, schema):
791        super().check(schema)
792        if self._arg_type_name:
793            self.arg_type = schema.resolve_type(
794                self._arg_type_name, self.info, "command's 'data'")
795            if not isinstance(self.arg_type, QAPISchemaObjectType):
796                raise QAPISemError(
797                    self.info,
798                    "command's 'data' cannot take %s"
799                    % self.arg_type.describe())
800            if self.arg_type.variants and not self.boxed:
801                raise QAPISemError(
802                    self.info,
803                    "command's 'data' can take %s only with 'boxed': true"
804                    % self.arg_type.describe())
805        if self._ret_type_name:
806            self.ret_type = schema.resolve_type(
807                self._ret_type_name, self.info, "command's 'returns'")
808            if self.name not in self.info.pragma.command_returns_exceptions:
809                typ = self.ret_type
810                if isinstance(typ, QAPISchemaArrayType):
811                    typ = self.ret_type.element_type
812                    assert typ
813                if not isinstance(typ, QAPISchemaObjectType):
814                    raise QAPISemError(
815                        self.info,
816                        "command's 'returns' cannot take %s"
817                        % self.ret_type.describe())
818
819    def connect_doc(self, doc=None):
820        super().connect_doc(doc)
821        doc = doc or self.doc
822        if doc:
823            if self.arg_type and self.arg_type.is_implicit():
824                self.arg_type.connect_doc(doc)
825
826    def visit(self, visitor):
827        super().visit(visitor)
828        visitor.visit_command(
829            self.name, self.info, self.ifcond, self.features,
830            self.arg_type, self.ret_type, self.gen, self.success_response,
831            self.boxed, self.allow_oob, self.allow_preconfig,
832            self.coroutine)
833
834
835class QAPISchemaEvent(QAPISchemaEntity):
836    meta = 'event'
837
838    def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
839        super().__init__(name, info, doc, ifcond, features)
840        assert not arg_type or isinstance(arg_type, str)
841        self._arg_type_name = arg_type
842        self.arg_type = None
843        self.boxed = boxed
844
845    def check(self, schema):
846        super().check(schema)
847        if self._arg_type_name:
848            self.arg_type = schema.resolve_type(
849                self._arg_type_name, self.info, "event's 'data'")
850            if not isinstance(self.arg_type, QAPISchemaObjectType):
851                raise QAPISemError(
852                    self.info,
853                    "event's 'data' cannot take %s"
854                    % self.arg_type.describe())
855            if self.arg_type.variants and not self.boxed:
856                raise QAPISemError(
857                    self.info,
858                    "event's 'data' can take %s only with 'boxed': true"
859                    % self.arg_type.describe())
860
861    def connect_doc(self, doc=None):
862        super().connect_doc(doc)
863        doc = doc or self.doc
864        if doc:
865            if self.arg_type and self.arg_type.is_implicit():
866                self.arg_type.connect_doc(doc)
867
868    def visit(self, visitor):
869        super().visit(visitor)
870        visitor.visit_event(
871            self.name, self.info, self.ifcond, self.features,
872            self.arg_type, self.boxed)
873
874
875class QAPISchema:
876    def __init__(self, fname):
877        self.fname = fname
878
879        try:
880            parser = QAPISchemaParser(fname)
881        except OSError as err:
882            raise QAPIError(
883                f"can't read schema file '{fname}': {err.strerror}"
884            ) from err
885
886        exprs = check_exprs(parser.exprs)
887        self.docs = parser.docs
888        self._entity_list = []
889        self._entity_dict = {}
890        self._module_dict = OrderedDict()
891        self._schema_dir = os.path.dirname(fname)
892        self._make_module(QAPISchemaModule.BUILTIN_MODULE_NAME)
893        self._make_module(fname)
894        self._predefining = True
895        self._def_predefineds()
896        self._predefining = False
897        self._def_exprs(exprs)
898        self.check()
899
900    def _def_entity(self, ent):
901        # Only the predefined types are allowed to not have info
902        assert ent.info or self._predefining
903        self._entity_list.append(ent)
904        if ent.name is None:
905            return
906        # TODO reject names that differ only in '_' vs. '.'  vs. '-',
907        # because they're liable to clash in generated C.
908        other_ent = self._entity_dict.get(ent.name)
909        if other_ent:
910            if other_ent.info:
911                where = QAPISourceError(other_ent.info, "previous definition")
912                raise QAPISemError(
913                    ent.info,
914                    "'%s' is already defined\n%s" % (ent.name, where))
915            raise QAPISemError(
916                ent.info, "%s is already defined" % other_ent.describe())
917        self._entity_dict[ent.name] = ent
918
919    def lookup_entity(self, name, typ=None):
920        ent = self._entity_dict.get(name)
921        if typ and not isinstance(ent, typ):
922            return None
923        return ent
924
925    def lookup_type(self, name):
926        return self.lookup_entity(name, QAPISchemaType)
927
928    def resolve_type(self, name, info, what):
929        typ = self.lookup_type(name)
930        if not typ:
931            if callable(what):
932                what = what(info)
933            raise QAPISemError(
934                info, "%s uses unknown type '%s'" % (what, name))
935        return typ
936
937    def _module_name(self, fname: str) -> str:
938        if QAPISchemaModule.is_system_module(fname):
939            return fname
940        return os.path.relpath(fname, self._schema_dir)
941
942    def _make_module(self, fname):
943        name = self._module_name(fname)
944        if name not in self._module_dict:
945            self._module_dict[name] = QAPISchemaModule(name)
946        return self._module_dict[name]
947
948    def module_by_fname(self, fname):
949        name = self._module_name(fname)
950        return self._module_dict[name]
951
952    def _def_include(self, expr, info, doc):
953        include = expr['include']
954        assert doc is None
955        self._def_entity(QAPISchemaInclude(self._make_module(include), info))
956
957    def _def_builtin_type(self, name, json_type, c_type):
958        self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
959        # Instantiating only the arrays that are actually used would
960        # be nice, but we can't as long as their generated code
961        # (qapi-builtin-types.[ch]) may be shared by some other
962        # schema.
963        self._make_array_type(name, None)
964
965    def _def_predefineds(self):
966        for t in [('str',    'string',  'char' + POINTER_SUFFIX),
967                  ('number', 'number',  'double'),
968                  ('int',    'int',     'int64_t'),
969                  ('int8',   'int',     'int8_t'),
970                  ('int16',  'int',     'int16_t'),
971                  ('int32',  'int',     'int32_t'),
972                  ('int64',  'int',     'int64_t'),
973                  ('uint8',  'int',     'uint8_t'),
974                  ('uint16', 'int',     'uint16_t'),
975                  ('uint32', 'int',     'uint32_t'),
976                  ('uint64', 'int',     'uint64_t'),
977                  ('size',   'int',     'uint64_t'),
978                  ('bool',   'boolean', 'bool'),
979                  ('any',    'value',   'QObject' + POINTER_SUFFIX),
980                  ('null',   'null',    'QNull' + POINTER_SUFFIX)]:
981            self._def_builtin_type(*t)
982        self.the_empty_object_type = QAPISchemaObjectType(
983            'q_empty', None, None, None, None, None, [], None)
984        self._def_entity(self.the_empty_object_type)
985
986        qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
987                  'qbool']
988        qtype_values = self._make_enum_members(
989            [{'name': n} for n in qtypes], None)
990
991        self._def_entity(QAPISchemaEnumType('QType', None, None, None, None,
992                                            qtype_values, 'QTYPE'))
993
994    def _make_features(self, features, info):
995        if features is None:
996            return []
997        return [QAPISchemaFeature(f['name'], info,
998                                  QAPISchemaIfCond(f.get('if')))
999                for f in features]
1000
1001    def _make_enum_member(self, name, ifcond, features, info):
1002        return QAPISchemaEnumMember(name, info,
1003                                    QAPISchemaIfCond(ifcond),
1004                                    self._make_features(features, info))
1005
1006    def _make_enum_members(self, values, info):
1007        return [self._make_enum_member(v['name'], v.get('if'),
1008                                       v.get('features'), info)
1009                for v in values]
1010
1011    def _make_array_type(self, element_type, info):
1012        name = element_type + 'List'    # reserved by check_defn_name_str()
1013        if not self.lookup_type(name):
1014            self._def_entity(QAPISchemaArrayType(name, info, element_type))
1015        return name
1016
1017    def _make_implicit_object_type(self, name, info, ifcond, role, members):
1018        if not members:
1019            return None
1020        # See also QAPISchemaObjectTypeMember.describe()
1021        name = 'q_obj_%s-%s' % (name, role)
1022        typ = self.lookup_entity(name, QAPISchemaObjectType)
1023        if typ:
1024            # The implicit object type has multiple users.  This can
1025            # only be a duplicate definition, which will be flagged
1026            # later.
1027            pass
1028        else:
1029            self._def_entity(QAPISchemaObjectType(
1030                name, info, None, ifcond, None, None, members, None))
1031        return name
1032
1033    def _def_enum_type(self, expr, info, doc):
1034        name = expr['enum']
1035        data = expr['data']
1036        prefix = expr.get('prefix')
1037        ifcond = QAPISchemaIfCond(expr.get('if'))
1038        features = self._make_features(expr.get('features'), info)
1039        self._def_entity(QAPISchemaEnumType(
1040            name, info, doc, ifcond, features,
1041            self._make_enum_members(data, info), prefix))
1042
1043    def _make_member(self, name, typ, ifcond, features, info):
1044        optional = False
1045        if name.startswith('*'):
1046            name = name[1:]
1047            optional = True
1048        if isinstance(typ, list):
1049            assert len(typ) == 1
1050            typ = self._make_array_type(typ[0], info)
1051        return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond,
1052                                          self._make_features(features, info))
1053
1054    def _make_members(self, data, info):
1055        return [self._make_member(key, value['type'],
1056                                  QAPISchemaIfCond(value.get('if')),
1057                                  value.get('features'), info)
1058                for (key, value) in data.items()]
1059
1060    def _def_struct_type(self, expr, info, doc):
1061        name = expr['struct']
1062        base = expr.get('base')
1063        data = expr['data']
1064        ifcond = QAPISchemaIfCond(expr.get('if'))
1065        features = self._make_features(expr.get('features'), info)
1066        self._def_entity(QAPISchemaObjectType(
1067            name, info, doc, ifcond, features, base,
1068            self._make_members(data, info),
1069            None))
1070
1071    def _make_variant(self, case, typ, ifcond, info):
1072        return QAPISchemaVariant(case, info, typ, ifcond)
1073
1074    def _def_union_type(self, expr, info, doc):
1075        name = expr['union']
1076        base = expr['base']
1077        tag_name = expr['discriminator']
1078        data = expr['data']
1079        ifcond = QAPISchemaIfCond(expr.get('if'))
1080        features = self._make_features(expr.get('features'), info)
1081        if isinstance(base, dict):
1082            base = self._make_implicit_object_type(
1083                name, info, ifcond,
1084                'base', self._make_members(base, info))
1085        variants = [
1086            self._make_variant(key, value['type'],
1087                               QAPISchemaIfCond(value.get('if')),
1088                               info)
1089            for (key, value) in data.items()]
1090        members = []
1091        self._def_entity(
1092            QAPISchemaObjectType(name, info, doc, ifcond, features,
1093                                 base, members,
1094                                 QAPISchemaVariants(
1095                                     tag_name, info, None, variants)))
1096
1097    def _def_alternate_type(self, expr, info, doc):
1098        name = expr['alternate']
1099        data = expr['data']
1100        ifcond = QAPISchemaIfCond(expr.get('if'))
1101        features = self._make_features(expr.get('features'), info)
1102        variants = [
1103            self._make_variant(key, value['type'],
1104                               QAPISchemaIfCond(value.get('if')),
1105                               info)
1106            for (key, value) in data.items()]
1107        tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1108        self._def_entity(
1109            QAPISchemaAlternateType(name, info, doc, ifcond, features,
1110                                    QAPISchemaVariants(
1111                                        None, info, tag_member, variants)))
1112
1113    def _def_command(self, expr, info, doc):
1114        name = expr['command']
1115        data = expr.get('data')
1116        rets = expr.get('returns')
1117        gen = expr.get('gen', True)
1118        success_response = expr.get('success-response', True)
1119        boxed = expr.get('boxed', False)
1120        allow_oob = expr.get('allow-oob', False)
1121        allow_preconfig = expr.get('allow-preconfig', False)
1122        coroutine = expr.get('coroutine', False)
1123        ifcond = QAPISchemaIfCond(expr.get('if'))
1124        features = self._make_features(expr.get('features'), info)
1125        if isinstance(data, OrderedDict):
1126            data = self._make_implicit_object_type(
1127                name, info, ifcond,
1128                'arg', self._make_members(data, info))
1129        if isinstance(rets, list):
1130            assert len(rets) == 1
1131            rets = self._make_array_type(rets[0], info)
1132        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, features,
1133                                           data, rets,
1134                                           gen, success_response,
1135                                           boxed, allow_oob, allow_preconfig,
1136                                           coroutine))
1137
1138    def _def_event(self, expr, info, doc):
1139        name = expr['event']
1140        data = expr.get('data')
1141        boxed = expr.get('boxed', False)
1142        ifcond = QAPISchemaIfCond(expr.get('if'))
1143        features = self._make_features(expr.get('features'), info)
1144        if isinstance(data, OrderedDict):
1145            data = self._make_implicit_object_type(
1146                name, info, ifcond,
1147                'arg', self._make_members(data, info))
1148        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, features,
1149                                         data, boxed))
1150
1151    def _def_exprs(self, exprs):
1152        for expr_elem in exprs:
1153            expr = expr_elem['expr']
1154            info = expr_elem['info']
1155            doc = expr_elem.get('doc')
1156            if 'enum' in expr:
1157                self._def_enum_type(expr, info, doc)
1158            elif 'struct' in expr:
1159                self._def_struct_type(expr, info, doc)
1160            elif 'union' in expr:
1161                self._def_union_type(expr, info, doc)
1162            elif 'alternate' in expr:
1163                self._def_alternate_type(expr, info, doc)
1164            elif 'command' in expr:
1165                self._def_command(expr, info, doc)
1166            elif 'event' in expr:
1167                self._def_event(expr, info, doc)
1168            elif 'include' in expr:
1169                self._def_include(expr, info, doc)
1170            else:
1171                assert False
1172
1173    def check(self):
1174        for ent in self._entity_list:
1175            ent.check(self)
1176            ent.connect_doc()
1177            ent.check_doc()
1178        for ent in self._entity_list:
1179            ent.set_module(self)
1180
1181    def visit(self, visitor):
1182        visitor.visit_begin(self)
1183        for mod in self._module_dict.values():
1184            mod.visit(visitor)
1185        visitor.visit_end()
1186