xref: /openbmc/qemu/scripts/qapi/schema.py (revision 7200fb21)
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 __repr__(self):
77        if self.name is None:
78            return "<%s at 0x%x>" % (type(self).__name__, id(self))
79        return "<%s:%s at 0x%x>" % (type(self).__name__, self.name,
80                                    id(self))
81
82    def c_name(self):
83        return c_name(self.name)
84
85    def check(self, schema):
86        assert not self._checked
87        seen = {}
88        for f in self.features:
89            f.check_clash(self.info, seen)
90        self._checked = True
91
92    def connect_doc(self, doc=None):
93        doc = doc or self.doc
94        if doc:
95            for f in self.features:
96                doc.connect_feature(f)
97
98    def check_doc(self):
99        if self.doc:
100            self.doc.check()
101
102    def _set_module(self, schema, info):
103        assert self._checked
104        fname = info.fname if info else QAPISchemaModule.BUILTIN_MODULE_NAME
105        self._module = schema.module_by_fname(fname)
106        self._module.add_entity(self)
107
108    def set_module(self, schema):
109        self._set_module(schema, self.info)
110
111    @property
112    def ifcond(self):
113        assert self._checked
114        return self._ifcond
115
116    def is_implicit(self):
117        return not self.info
118
119    def visit(self, visitor):
120        assert self._checked
121
122    def describe(self):
123        assert self.meta
124        return "%s '%s'" % (self.meta, self.name)
125
126
127class QAPISchemaVisitor:
128    def visit_begin(self, schema):
129        pass
130
131    def visit_end(self):
132        pass
133
134    def visit_module(self, name):
135        pass
136
137    def visit_needed(self, entity):
138        # Default to visiting everything
139        return True
140
141    def visit_include(self, name, info):
142        pass
143
144    def visit_builtin_type(self, name, info, json_type):
145        pass
146
147    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
148        pass
149
150    def visit_array_type(self, name, info, ifcond, element_type):
151        pass
152
153    def visit_object_type(self, name, info, ifcond, features,
154                          base, members, variants):
155        pass
156
157    def visit_object_type_flat(self, name, info, ifcond, features,
158                               members, variants):
159        pass
160
161    def visit_alternate_type(self, name, info, ifcond, features, variants):
162        pass
163
164    def visit_command(self, name, info, ifcond, features,
165                      arg_type, ret_type, gen, success_response, boxed,
166                      allow_oob, allow_preconfig, coroutine):
167        pass
168
169    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
170        pass
171
172
173class QAPISchemaModule:
174
175    BUILTIN_MODULE_NAME = './builtin'
176
177    def __init__(self, name):
178        self.name = name
179        self._entity_list = []
180
181    @staticmethod
182    def is_system_module(name: str) -> bool:
183        """
184        System modules are internally defined modules.
185
186        Their names start with the "./" prefix.
187        """
188        return name.startswith('./')
189
190    @classmethod
191    def is_user_module(cls, name: str) -> bool:
192        """
193        User modules are those defined by the user in qapi JSON files.
194
195        They do not start with the "./" prefix.
196        """
197        return not cls.is_system_module(name)
198
199    @classmethod
200    def is_builtin_module(cls, name: str) -> bool:
201        """
202        The built-in module is a single System module for the built-in types.
203
204        It is always "./builtin".
205        """
206        return name == cls.BUILTIN_MODULE_NAME
207
208    def add_entity(self, ent):
209        self._entity_list.append(ent)
210
211    def visit(self, visitor):
212        visitor.visit_module(self.name)
213        for entity in self._entity_list:
214            if visitor.visit_needed(entity):
215                entity.visit(visitor)
216
217
218class QAPISchemaInclude(QAPISchemaEntity):
219    def __init__(self, sub_module, info):
220        super().__init__(None, info, None)
221        self._sub_module = sub_module
222
223    def visit(self, visitor):
224        super().visit(visitor)
225        visitor.visit_include(self._sub_module.name, self.info)
226
227
228class QAPISchemaType(QAPISchemaEntity):
229    # Return the C type for common use.
230    # For the types we commonly box, this is a pointer type.
231    def c_type(self):
232        pass
233
234    # Return the C type to be used in a parameter list.
235    def c_param_type(self):
236        return self.c_type()
237
238    # Return the C type to be used where we suppress boxing.
239    def c_unboxed_type(self):
240        return self.c_type()
241
242    def json_type(self):
243        pass
244
245    def alternate_qtype(self):
246        json2qtype = {
247            'null':    'QTYPE_QNULL',
248            'string':  'QTYPE_QSTRING',
249            'number':  'QTYPE_QNUM',
250            'int':     'QTYPE_QNUM',
251            'boolean': 'QTYPE_QBOOL',
252            'array':   'QTYPE_QLIST',
253            'object':  'QTYPE_QDICT'
254        }
255        return json2qtype.get(self.json_type())
256
257    def doc_type(self):
258        if self.is_implicit():
259            return None
260        return self.name
261
262    def need_has_if_optional(self):
263        # When FOO is a pointer, has_FOO == !!FOO, i.e. has_FOO is redundant.
264        # Except for arrays; see QAPISchemaArrayType.need_has_if_optional().
265        return not self.c_type().endswith(POINTER_SUFFIX)
266
267    def check(self, schema):
268        super().check(schema)
269        for feat in self.features:
270            if feat.is_special():
271                raise QAPISemError(
272                    self.info,
273                    f"feature '{feat.name}' is not supported for types")
274
275    def describe(self):
276        assert self.meta
277        return "%s type '%s'" % (self.meta, self.name)
278
279
280class QAPISchemaBuiltinType(QAPISchemaType):
281    meta = 'built-in'
282
283    def __init__(self, name, json_type, c_type):
284        super().__init__(name, None, None)
285        assert not c_type or isinstance(c_type, str)
286        assert json_type in ('string', 'number', 'int', 'boolean', 'null',
287                             'value')
288        self._json_type_name = json_type
289        self._c_type_name = c_type
290
291    def c_name(self):
292        return self.name
293
294    def c_type(self):
295        return self._c_type_name
296
297    def c_param_type(self):
298        if self.name == 'str':
299            return 'const ' + self._c_type_name
300        return self._c_type_name
301
302    def json_type(self):
303        return self._json_type_name
304
305    def doc_type(self):
306        return self.json_type()
307
308    def visit(self, visitor):
309        super().visit(visitor)
310        visitor.visit_builtin_type(self.name, self.info, self.json_type())
311
312
313class QAPISchemaEnumType(QAPISchemaType):
314    meta = 'enum'
315
316    def __init__(self, name, info, doc, ifcond, features, members, prefix):
317        super().__init__(name, info, doc, ifcond, features)
318        for m in members:
319            assert isinstance(m, QAPISchemaEnumMember)
320            m.set_defined_in(name)
321        assert prefix is None or isinstance(prefix, str)
322        self.members = members
323        self.prefix = prefix
324
325    def check(self, schema):
326        super().check(schema)
327        seen = {}
328        for m in self.members:
329            m.check_clash(self.info, seen)
330
331    def connect_doc(self, doc=None):
332        super().connect_doc(doc)
333        doc = doc or self.doc
334        for m in self.members:
335            m.connect_doc(doc)
336
337    def is_implicit(self):
338        # See QAPISchema._def_predefineds()
339        return self.name == 'QType'
340
341    def c_type(self):
342        return c_name(self.name)
343
344    def member_names(self):
345        return [m.name for m in self.members]
346
347    def json_type(self):
348        return 'string'
349
350    def visit(self, visitor):
351        super().visit(visitor)
352        visitor.visit_enum_type(
353            self.name, self.info, self.ifcond, self.features,
354            self.members, self.prefix)
355
356
357class QAPISchemaArrayType(QAPISchemaType):
358    meta = 'array'
359
360    def __init__(self, name, info, element_type):
361        super().__init__(name, info, None)
362        assert isinstance(element_type, str)
363        self._element_type_name = element_type
364        self.element_type = None
365
366    def need_has_if_optional(self):
367        # When FOO is an array, we still need has_FOO to distinguish
368        # absent (!has_FOO) from present and empty (has_FOO && !FOO).
369        return True
370
371    def check(self, schema):
372        super().check(schema)
373        self.element_type = schema.resolve_type(
374            self._element_type_name, self.info,
375            self.info and self.info.defn_meta)
376        assert not isinstance(self.element_type, QAPISchemaArrayType)
377
378    def set_module(self, schema):
379        self._set_module(schema, self.element_type.info)
380
381    @property
382    def ifcond(self):
383        assert self._checked
384        return self.element_type.ifcond
385
386    def is_implicit(self):
387        return True
388
389    def c_type(self):
390        return c_name(self.name) + POINTER_SUFFIX
391
392    def json_type(self):
393        return 'array'
394
395    def doc_type(self):
396        elt_doc_type = self.element_type.doc_type()
397        if not elt_doc_type:
398            return None
399        return 'array of ' + elt_doc_type
400
401    def visit(self, visitor):
402        super().visit(visitor)
403        visitor.visit_array_type(self.name, self.info, self.ifcond,
404                                 self.element_type)
405
406    def describe(self):
407        assert self.meta
408        return "%s type ['%s']" % (self.meta, self._element_type_name)
409
410
411class QAPISchemaObjectType(QAPISchemaType):
412    def __init__(self, name, info, doc, ifcond, features,
413                 base, local_members, variants):
414        # struct has local_members, optional base, and no variants
415        # union has base, variants, and no local_members
416        super().__init__(name, info, doc, ifcond, features)
417        self.meta = 'union' if variants else 'struct'
418        assert base is None or isinstance(base, str)
419        for m in local_members:
420            assert isinstance(m, QAPISchemaObjectTypeMember)
421            m.set_defined_in(name)
422        if variants is not None:
423            assert isinstance(variants, QAPISchemaVariants)
424            variants.set_defined_in(name)
425        self._base_name = base
426        self.base = None
427        self.local_members = local_members
428        self.variants = variants
429        self.members = None
430
431    def check(self, schema):
432        # This calls another type T's .check() exactly when the C
433        # struct emitted by gen_object() contains that T's C struct
434        # (pointers don't count).
435        if self.members is not None:
436            # A previous .check() completed: nothing to do
437            return
438        if self._checked:
439            # Recursed: C struct contains itself
440            raise QAPISemError(self.info,
441                               "object %s contains itself" % self.name)
442
443        super().check(schema)
444        assert self._checked and self.members is None
445
446        seen = OrderedDict()
447        if self._base_name:
448            self.base = schema.resolve_type(self._base_name, self.info,
449                                            "'base'")
450            if (not isinstance(self.base, QAPISchemaObjectType)
451                    or self.base.variants):
452                raise QAPISemError(
453                    self.info,
454                    "'base' requires a struct type, %s isn't"
455                    % self.base.describe())
456            self.base.check(schema)
457            self.base.check_clash(self.info, seen)
458        for m in self.local_members:
459            m.check(schema)
460            m.check_clash(self.info, seen)
461        members = seen.values()
462
463        if self.variants:
464            self.variants.check(schema, seen)
465            self.variants.check_clash(self.info, seen)
466
467        self.members = members  # mark completed
468
469    # Check that the members of this type do not cause duplicate JSON members,
470    # and update seen to track the members seen so far. Report any errors
471    # on behalf of info, which is not necessarily self.info
472    def check_clash(self, info, seen):
473        assert self._checked
474        for m in self.members:
475            m.check_clash(info, seen)
476        if self.variants:
477            self.variants.check_clash(info, seen)
478
479    def connect_doc(self, doc=None):
480        super().connect_doc(doc)
481        doc = doc or self.doc
482        if self.base and self.base.is_implicit():
483            self.base.connect_doc(doc)
484        for m in self.local_members:
485            m.connect_doc(doc)
486
487    def is_implicit(self):
488        # See QAPISchema._make_implicit_object_type(), as well as
489        # _def_predefineds()
490        return self.name.startswith('q_')
491
492    def is_empty(self):
493        assert self.members is not None
494        return not self.members and not self.variants
495
496    def has_conditional_members(self):
497        assert self.members is not None
498        return any(m.ifcond.is_present() for m in self.members)
499
500    def c_name(self):
501        assert self.name != 'q_empty'
502        return super().c_name()
503
504    def c_type(self):
505        assert not self.is_implicit()
506        return c_name(self.name) + POINTER_SUFFIX
507
508    def c_unboxed_type(self):
509        return c_name(self.name)
510
511    def json_type(self):
512        return 'object'
513
514    def visit(self, visitor):
515        super().visit(visitor)
516        visitor.visit_object_type(
517            self.name, self.info, self.ifcond, self.features,
518            self.base, self.local_members, self.variants)
519        visitor.visit_object_type_flat(
520            self.name, self.info, self.ifcond, self.features,
521            self.members, self.variants)
522
523
524class QAPISchemaAlternateType(QAPISchemaType):
525    meta = 'alternate'
526
527    def __init__(self, name, info, doc, ifcond, features, variants):
528        super().__init__(name, info, doc, ifcond, features)
529        assert isinstance(variants, QAPISchemaVariants)
530        assert variants.tag_member
531        variants.set_defined_in(name)
532        variants.tag_member.set_defined_in(self.name)
533        self.variants = variants
534
535    def check(self, schema):
536        super().check(schema)
537        self.variants.tag_member.check(schema)
538        # Not calling self.variants.check_clash(), because there's nothing
539        # to clash with
540        self.variants.check(schema, {})
541        # Alternate branch names have no relation to the tag enum values;
542        # so we have to check for potential name collisions ourselves.
543        seen = {}
544        types_seen = {}
545        for v in self.variants.variants:
546            v.check_clash(self.info, seen)
547            qtype = v.type.alternate_qtype()
548            if not qtype:
549                raise QAPISemError(
550                    self.info,
551                    "%s cannot use %s"
552                    % (v.describe(self.info), v.type.describe()))
553            conflicting = set([qtype])
554            if qtype == 'QTYPE_QSTRING':
555                if isinstance(v.type, QAPISchemaEnumType):
556                    for m in v.type.members:
557                        if m.name in ['on', 'off']:
558                            conflicting.add('QTYPE_QBOOL')
559                        if re.match(r'[-+0-9.]', m.name):
560                            # lazy, could be tightened
561                            conflicting.add('QTYPE_QNUM')
562                else:
563                    conflicting.add('QTYPE_QNUM')
564                    conflicting.add('QTYPE_QBOOL')
565            for qt in conflicting:
566                if qt in types_seen:
567                    raise QAPISemError(
568                        self.info,
569                        "%s can't be distinguished from '%s'"
570                        % (v.describe(self.info), types_seen[qt]))
571                types_seen[qt] = v.name
572
573    def connect_doc(self, doc=None):
574        super().connect_doc(doc)
575        doc = doc or self.doc
576        for v in self.variants.variants:
577            v.connect_doc(doc)
578
579    def c_type(self):
580        return c_name(self.name) + POINTER_SUFFIX
581
582    def json_type(self):
583        return 'value'
584
585    def visit(self, visitor):
586        super().visit(visitor)
587        visitor.visit_alternate_type(
588            self.name, self.info, self.ifcond, self.features, self.variants)
589
590
591class QAPISchemaVariants:
592    def __init__(self, tag_name, info, tag_member, variants):
593        # Unions pass tag_name but not tag_member.
594        # Alternates pass tag_member but not tag_name.
595        # After check(), tag_member is always set.
596        assert bool(tag_member) != bool(tag_name)
597        assert (isinstance(tag_name, str) or
598                isinstance(tag_member, QAPISchemaObjectTypeMember))
599        for v in variants:
600            assert isinstance(v, QAPISchemaVariant)
601        self._tag_name = tag_name
602        self.info = info
603        self.tag_member = tag_member
604        self.variants = variants
605
606    def set_defined_in(self, name):
607        for v in self.variants:
608            v.set_defined_in(name)
609
610    def check(self, schema, seen):
611        if self._tag_name:      # union
612            self.tag_member = seen.get(c_name(self._tag_name))
613            base = "'base'"
614            # Pointing to the base type when not implicit would be
615            # nice, but we don't know it here
616            if not self.tag_member or self._tag_name != self.tag_member.name:
617                raise QAPISemError(
618                    self.info,
619                    "discriminator '%s' is not a member of %s"
620                    % (self._tag_name, base))
621            # Here we do:
622            base_type = schema.lookup_type(self.tag_member.defined_in)
623            assert base_type
624            if not base_type.is_implicit():
625                base = "base type '%s'" % self.tag_member.defined_in
626            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
627                raise QAPISemError(
628                    self.info,
629                    "discriminator member '%s' of %s must be of enum type"
630                    % (self._tag_name, base))
631            if self.tag_member.optional:
632                raise QAPISemError(
633                    self.info,
634                    "discriminator member '%s' of %s must not be optional"
635                    % (self._tag_name, base))
636            if self.tag_member.ifcond.is_present():
637                raise QAPISemError(
638                    self.info,
639                    "discriminator member '%s' of %s must not be conditional"
640                    % (self._tag_name, base))
641        else:                   # alternate
642            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
643            assert not self.tag_member.optional
644            assert not self.tag_member.ifcond.is_present()
645        if self._tag_name:      # union
646            # branches that are not explicitly covered get an empty type
647            cases = {v.name for v in self.variants}
648            for m in self.tag_member.type.members:
649                if m.name not in cases:
650                    v = QAPISchemaVariant(m.name, self.info,
651                                          'q_empty', m.ifcond)
652                    v.set_defined_in(self.tag_member.defined_in)
653                    self.variants.append(v)
654        if not self.variants:
655            raise QAPISemError(self.info, "union has no branches")
656        for v in self.variants:
657            v.check(schema)
658            # Union names must match enum values; alternate names are
659            # checked separately. Use 'seen' to tell the two apart.
660            if seen:
661                if v.name not in self.tag_member.type.member_names():
662                    raise QAPISemError(
663                        self.info,
664                        "branch '%s' is not a value of %s"
665                        % (v.name, self.tag_member.type.describe()))
666                if not isinstance(v.type, QAPISchemaObjectType):
667                    raise QAPISemError(
668                        self.info,
669                        "%s cannot use %s"
670                        % (v.describe(self.info), v.type.describe()))
671                v.type.check(schema)
672
673    def check_clash(self, info, seen):
674        for v in self.variants:
675            # Reset seen map for each variant, since qapi names from one
676            # branch do not affect another branch
677            v.type.check_clash(info, dict(seen))
678
679
680class QAPISchemaMember:
681    """ Represents object members, enum members and features """
682    role = 'member'
683
684    def __init__(self, name, info, ifcond=None):
685        assert isinstance(name, str)
686        self.name = name
687        self.info = info
688        self.ifcond = ifcond or QAPISchemaIfCond()
689        self.defined_in = None
690
691    def set_defined_in(self, name):
692        assert not self.defined_in
693        self.defined_in = name
694
695    def check_clash(self, info, seen):
696        cname = c_name(self.name)
697        if cname in seen:
698            raise QAPISemError(
699                info,
700                "%s collides with %s"
701                % (self.describe(info), seen[cname].describe(info)))
702        seen[cname] = self
703
704    def connect_doc(self, doc):
705        if doc:
706            doc.connect_member(self)
707
708    def describe(self, info):
709        role = self.role
710        meta = 'type'
711        defined_in = self.defined_in
712        assert defined_in
713
714        if defined_in.startswith('q_obj_'):
715            # See QAPISchema._make_implicit_object_type() - reverse the
716            # mapping there to create a nice human-readable description
717            defined_in = defined_in[6:]
718            if defined_in.endswith('-arg'):
719                # Implicit type created for a command's dict 'data'
720                assert role == 'member'
721                role = 'parameter'
722                meta = 'command'
723                defined_in = defined_in[:-4]
724            elif defined_in.endswith('-base'):
725                # Implicit type created for a union's dict 'base'
726                role = 'base ' + role
727                defined_in = defined_in[:-5]
728            else:
729                assert False
730
731        if defined_in != info.defn_name:
732            return "%s '%s' of %s '%s'" % (role, self.name, meta, defined_in)
733        return "%s '%s'" % (role, self.name)
734
735
736class QAPISchemaEnumMember(QAPISchemaMember):
737    role = 'value'
738
739    def __init__(self, name, info, ifcond=None, features=None):
740        super().__init__(name, info, ifcond)
741        for f in features or []:
742            assert isinstance(f, QAPISchemaFeature)
743            f.set_defined_in(name)
744        self.features = features or []
745
746    def connect_doc(self, doc):
747        super().connect_doc(doc)
748        if doc:
749            for f in self.features:
750                doc.connect_feature(f)
751
752
753class QAPISchemaFeature(QAPISchemaMember):
754    role = 'feature'
755
756    def is_special(self):
757        return self.name in ('deprecated', 'unstable')
758
759
760class QAPISchemaObjectTypeMember(QAPISchemaMember):
761    def __init__(self, name, info, typ, optional, ifcond=None, features=None):
762        super().__init__(name, info, ifcond)
763        assert isinstance(typ, str)
764        assert isinstance(optional, bool)
765        for f in features or []:
766            assert isinstance(f, QAPISchemaFeature)
767            f.set_defined_in(name)
768        self._type_name = typ
769        self.type = None
770        self.optional = optional
771        self.features = features or []
772
773    def need_has(self):
774        assert self.type
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            self.arg_type.check(schema)
836            if self.arg_type.has_conditional_members() and not self.boxed:
837                raise QAPISemError(
838                    self.info,
839                    "conditional command arguments require 'boxed': true")
840        if self._ret_type_name:
841            self.ret_type = schema.resolve_type(
842                self._ret_type_name, self.info, "command's 'returns'")
843            if self.name not in self.info.pragma.command_returns_exceptions:
844                typ = self.ret_type
845                if isinstance(typ, QAPISchemaArrayType):
846                    typ = self.ret_type.element_type
847                    assert typ
848                if not isinstance(typ, QAPISchemaObjectType):
849                    raise QAPISemError(
850                        self.info,
851                        "command's 'returns' cannot take %s"
852                        % self.ret_type.describe())
853
854    def connect_doc(self, doc=None):
855        super().connect_doc(doc)
856        doc = doc or self.doc
857        if doc:
858            if self.arg_type and self.arg_type.is_implicit():
859                self.arg_type.connect_doc(doc)
860
861    def visit(self, visitor):
862        super().visit(visitor)
863        visitor.visit_command(
864            self.name, self.info, self.ifcond, self.features,
865            self.arg_type, self.ret_type, self.gen, self.success_response,
866            self.boxed, self.allow_oob, self.allow_preconfig,
867            self.coroutine)
868
869
870class QAPISchemaEvent(QAPISchemaEntity):
871    meta = 'event'
872
873    def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
874        super().__init__(name, info, doc, ifcond, features)
875        assert not arg_type or isinstance(arg_type, str)
876        self._arg_type_name = arg_type
877        self.arg_type = None
878        self.boxed = boxed
879
880    def check(self, schema):
881        super().check(schema)
882        if self._arg_type_name:
883            self.arg_type = schema.resolve_type(
884                self._arg_type_name, self.info, "event's 'data'")
885            if not isinstance(self.arg_type, QAPISchemaObjectType):
886                raise QAPISemError(
887                    self.info,
888                    "event's 'data' cannot take %s"
889                    % self.arg_type.describe())
890            if self.arg_type.variants and not self.boxed:
891                raise QAPISemError(
892                    self.info,
893                    "event's 'data' can take %s only with 'boxed': true"
894                    % self.arg_type.describe())
895            self.arg_type.check(schema)
896            if self.arg_type.has_conditional_members() and not self.boxed:
897                raise QAPISemError(
898                    self.info,
899                    "conditional event arguments require 'boxed': true")
900
901    def connect_doc(self, doc=None):
902        super().connect_doc(doc)
903        doc = doc or self.doc
904        if doc:
905            if self.arg_type and self.arg_type.is_implicit():
906                self.arg_type.connect_doc(doc)
907
908    def visit(self, visitor):
909        super().visit(visitor)
910        visitor.visit_event(
911            self.name, self.info, self.ifcond, self.features,
912            self.arg_type, self.boxed)
913
914
915class QAPISchema:
916    def __init__(self, fname):
917        self.fname = fname
918
919        try:
920            parser = QAPISchemaParser(fname)
921        except OSError as err:
922            raise QAPIError(
923                f"can't read schema file '{fname}': {err.strerror}"
924            ) from err
925
926        exprs = check_exprs(parser.exprs)
927        self.docs = parser.docs
928        self._entity_list = []
929        self._entity_dict = {}
930        self._module_dict = OrderedDict()
931        self._schema_dir = os.path.dirname(fname)
932        self._make_module(QAPISchemaModule.BUILTIN_MODULE_NAME)
933        self._make_module(fname)
934        self._predefining = True
935        self._def_predefineds()
936        self._predefining = False
937        self._def_exprs(exprs)
938        self.check()
939
940    def _def_entity(self, ent):
941        # Only the predefined types are allowed to not have info
942        assert ent.info or self._predefining
943        self._entity_list.append(ent)
944        if ent.name is None:
945            return
946        # TODO reject names that differ only in '_' vs. '.'  vs. '-',
947        # because they're liable to clash in generated C.
948        other_ent = self._entity_dict.get(ent.name)
949        if other_ent:
950            if other_ent.info:
951                where = QAPISourceError(other_ent.info, "previous definition")
952                raise QAPISemError(
953                    ent.info,
954                    "'%s' is already defined\n%s" % (ent.name, where))
955            raise QAPISemError(
956                ent.info, "%s is already defined" % other_ent.describe())
957        self._entity_dict[ent.name] = ent
958
959    def lookup_entity(self, name, typ=None):
960        ent = self._entity_dict.get(name)
961        if typ and not isinstance(ent, typ):
962            return None
963        return ent
964
965    def lookup_type(self, name):
966        return self.lookup_entity(name, QAPISchemaType)
967
968    def resolve_type(self, name, info, what):
969        typ = self.lookup_type(name)
970        if not typ:
971            if callable(what):
972                what = what(info)
973            raise QAPISemError(
974                info, "%s uses unknown type '%s'" % (what, name))
975        return typ
976
977    def _module_name(self, fname: str) -> str:
978        if QAPISchemaModule.is_system_module(fname):
979            return fname
980        return os.path.relpath(fname, self._schema_dir)
981
982    def _make_module(self, fname):
983        name = self._module_name(fname)
984        if name not in self._module_dict:
985            self._module_dict[name] = QAPISchemaModule(name)
986        return self._module_dict[name]
987
988    def module_by_fname(self, fname):
989        name = self._module_name(fname)
990        return self._module_dict[name]
991
992    def _def_include(self, expr: QAPIExpression):
993        include = expr['include']
994        assert expr.doc is None
995        self._def_entity(
996            QAPISchemaInclude(self._make_module(include), expr.info))
997
998    def _def_builtin_type(self, name, json_type, c_type):
999        self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
1000        # Instantiating only the arrays that are actually used would
1001        # be nice, but we can't as long as their generated code
1002        # (qapi-builtin-types.[ch]) may be shared by some other
1003        # schema.
1004        self._make_array_type(name, None)
1005
1006    def _def_predefineds(self):
1007        for t in [('str',    'string',  'char' + POINTER_SUFFIX),
1008                  ('number', 'number',  'double'),
1009                  ('int',    'int',     'int64_t'),
1010                  ('int8',   'int',     'int8_t'),
1011                  ('int16',  'int',     'int16_t'),
1012                  ('int32',  'int',     'int32_t'),
1013                  ('int64',  'int',     'int64_t'),
1014                  ('uint8',  'int',     'uint8_t'),
1015                  ('uint16', 'int',     'uint16_t'),
1016                  ('uint32', 'int',     'uint32_t'),
1017                  ('uint64', 'int',     'uint64_t'),
1018                  ('size',   'int',     'uint64_t'),
1019                  ('bool',   'boolean', 'bool'),
1020                  ('any',    'value',   'QObject' + POINTER_SUFFIX),
1021                  ('null',   'null',    'QNull' + POINTER_SUFFIX)]:
1022            self._def_builtin_type(*t)
1023        self.the_empty_object_type = QAPISchemaObjectType(
1024            'q_empty', None, None, None, None, None, [], None)
1025        self._def_entity(self.the_empty_object_type)
1026
1027        qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
1028                  'qbool']
1029        qtype_values = self._make_enum_members(
1030            [{'name': n} for n in qtypes], None)
1031
1032        self._def_entity(QAPISchemaEnumType('QType', None, None, None, None,
1033                                            qtype_values, 'QTYPE'))
1034
1035    def _make_features(self, features, info):
1036        if features is None:
1037            return []
1038        return [QAPISchemaFeature(f['name'], info,
1039                                  QAPISchemaIfCond(f.get('if')))
1040                for f in features]
1041
1042    def _make_enum_member(self, name, ifcond, features, info):
1043        return QAPISchemaEnumMember(name, info,
1044                                    QAPISchemaIfCond(ifcond),
1045                                    self._make_features(features, info))
1046
1047    def _make_enum_members(self, values, info):
1048        return [self._make_enum_member(v['name'], v.get('if'),
1049                                       v.get('features'), info)
1050                for v in values]
1051
1052    def _make_array_type(self, element_type, info):
1053        name = element_type + 'List'    # reserved by check_defn_name_str()
1054        if not self.lookup_type(name):
1055            self._def_entity(QAPISchemaArrayType(name, info, element_type))
1056        return name
1057
1058    def _make_implicit_object_type(self, name, info, ifcond, role, members):
1059        if not members:
1060            return None
1061        # See also QAPISchemaObjectTypeMember.describe()
1062        name = 'q_obj_%s-%s' % (name, role)
1063        typ = self.lookup_entity(name, QAPISchemaObjectType)
1064        if typ:
1065            # The implicit object type has multiple users.  This can
1066            # only be a duplicate definition, which will be flagged
1067            # later.
1068            pass
1069        else:
1070            self._def_entity(QAPISchemaObjectType(
1071                name, info, None, ifcond, None, None, members, None))
1072        return name
1073
1074    def _def_enum_type(self, expr: QAPIExpression):
1075        name = expr['enum']
1076        data = expr['data']
1077        prefix = expr.get('prefix')
1078        ifcond = QAPISchemaIfCond(expr.get('if'))
1079        info = expr.info
1080        features = self._make_features(expr.get('features'), info)
1081        self._def_entity(QAPISchemaEnumType(
1082            name, info, expr.doc, ifcond, features,
1083            self._make_enum_members(data, info), prefix))
1084
1085    def _make_member(self, name, typ, ifcond, features, info):
1086        optional = False
1087        if name.startswith('*'):
1088            name = name[1:]
1089            optional = True
1090        if isinstance(typ, list):
1091            assert len(typ) == 1
1092            typ = self._make_array_type(typ[0], info)
1093        return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond,
1094                                          self._make_features(features, info))
1095
1096    def _make_members(self, data, info):
1097        return [self._make_member(key, value['type'],
1098                                  QAPISchemaIfCond(value.get('if')),
1099                                  value.get('features'), info)
1100                for (key, value) in data.items()]
1101
1102    def _def_struct_type(self, expr: QAPIExpression):
1103        name = expr['struct']
1104        base = expr.get('base')
1105        data = expr['data']
1106        info = expr.info
1107        ifcond = QAPISchemaIfCond(expr.get('if'))
1108        features = self._make_features(expr.get('features'), info)
1109        self._def_entity(QAPISchemaObjectType(
1110            name, info, expr.doc, ifcond, features, base,
1111            self._make_members(data, info),
1112            None))
1113
1114    def _make_variant(self, case, typ, ifcond, info):
1115        if isinstance(typ, list):
1116            assert len(typ) == 1
1117            typ = self._make_array_type(typ[0], info)
1118        return QAPISchemaVariant(case, info, typ, ifcond)
1119
1120    def _def_union_type(self, expr: QAPIExpression):
1121        name = expr['union']
1122        base = expr['base']
1123        tag_name = expr['discriminator']
1124        data = expr['data']
1125        assert isinstance(data, dict)
1126        info = expr.info
1127        ifcond = QAPISchemaIfCond(expr.get('if'))
1128        features = self._make_features(expr.get('features'), info)
1129        if isinstance(base, dict):
1130            base = self._make_implicit_object_type(
1131                name, info, ifcond,
1132                'base', self._make_members(base, info))
1133        variants = [
1134            self._make_variant(key, value['type'],
1135                               QAPISchemaIfCond(value.get('if')),
1136                               info)
1137            for (key, value) in data.items()]
1138        members: List[QAPISchemaObjectTypeMember] = []
1139        self._def_entity(
1140            QAPISchemaObjectType(name, info, expr.doc, ifcond, features,
1141                                 base, members,
1142                                 QAPISchemaVariants(
1143                                     tag_name, info, None, variants)))
1144
1145    def _def_alternate_type(self, expr: QAPIExpression):
1146        name = expr['alternate']
1147        data = expr['data']
1148        assert isinstance(data, dict)
1149        ifcond = QAPISchemaIfCond(expr.get('if'))
1150        info = expr.info
1151        features = self._make_features(expr.get('features'), info)
1152        variants = [
1153            self._make_variant(key, value['type'],
1154                               QAPISchemaIfCond(value.get('if')),
1155                               info)
1156            for (key, value) in data.items()]
1157        tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1158        self._def_entity(
1159            QAPISchemaAlternateType(
1160                name, info, expr.doc, ifcond, features,
1161                QAPISchemaVariants(None, info, tag_member, variants)))
1162
1163    def _def_command(self, expr: QAPIExpression):
1164        name = expr['command']
1165        data = expr.get('data')
1166        rets = expr.get('returns')
1167        gen = expr.get('gen', True)
1168        success_response = expr.get('success-response', True)
1169        boxed = expr.get('boxed', False)
1170        allow_oob = expr.get('allow-oob', False)
1171        allow_preconfig = expr.get('allow-preconfig', False)
1172        coroutine = expr.get('coroutine', False)
1173        ifcond = QAPISchemaIfCond(expr.get('if'))
1174        info = expr.info
1175        features = self._make_features(expr.get('features'), info)
1176        if isinstance(data, OrderedDict):
1177            data = self._make_implicit_object_type(
1178                name, info, ifcond,
1179                'arg', self._make_members(data, info))
1180        if isinstance(rets, list):
1181            assert len(rets) == 1
1182            rets = self._make_array_type(rets[0], info)
1183        self._def_entity(QAPISchemaCommand(name, info, expr.doc, ifcond,
1184                                           features, data, rets,
1185                                           gen, success_response,
1186                                           boxed, allow_oob, allow_preconfig,
1187                                           coroutine))
1188
1189    def _def_event(self, expr: QAPIExpression):
1190        name = expr['event']
1191        data = expr.get('data')
1192        boxed = expr.get('boxed', False)
1193        ifcond = QAPISchemaIfCond(expr.get('if'))
1194        info = expr.info
1195        features = self._make_features(expr.get('features'), info)
1196        if isinstance(data, OrderedDict):
1197            data = self._make_implicit_object_type(
1198                name, info, ifcond,
1199                'arg', self._make_members(data, info))
1200        self._def_entity(QAPISchemaEvent(name, info, expr.doc, ifcond,
1201                                         features, data, boxed))
1202
1203    def _def_exprs(self, exprs):
1204        for expr in exprs:
1205            if 'enum' in expr:
1206                self._def_enum_type(expr)
1207            elif 'struct' in expr:
1208                self._def_struct_type(expr)
1209            elif 'union' in expr:
1210                self._def_union_type(expr)
1211            elif 'alternate' in expr:
1212                self._def_alternate_type(expr)
1213            elif 'command' in expr:
1214                self._def_command(expr)
1215            elif 'event' in expr:
1216                self._def_event(expr)
1217            elif 'include' in expr:
1218                self._def_include(expr)
1219            else:
1220                assert False
1221
1222    def check(self):
1223        for ent in self._entity_list:
1224            ent.check(self)
1225            ent.connect_doc()
1226            ent.check_doc()
1227        for ent in self._entity_list:
1228            ent.set_module(self)
1229
1230    def visit(self, visitor):
1231        visitor.visit_begin(self)
1232        for mod in self._module_dict.values():
1233            mod.visit(visitor)
1234        visitor.visit_end()
1235