xref: /openbmc/qemu/scripts/qapi/schema.py (revision 84ab00868798a65e19d76d3cb5f1552c6b25ceb4)
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
17import os
18import re
19from collections import OrderedDict
20
21from qapi.common import c_name, pointer_suffix
22from qapi.error import QAPIError, QAPISemError
23from qapi.expr import check_exprs
24from qapi.parser import QAPISchemaParser
25
26
27class QAPISchemaEntity:
28    meta = None
29
30    def __init__(self, name, info, doc, ifcond=None, features=None):
31        assert name is None or isinstance(name, str)
32        for f in features or []:
33            assert isinstance(f, QAPISchemaFeature)
34            f.set_defined_in(name)
35        self.name = name
36        self._module = None
37        # For explicitly defined entities, info points to the (explicit)
38        # definition.  For builtins (and their arrays), info is None.
39        # For implicitly defined entities, info points to a place that
40        # triggered the implicit definition (there may be more than one
41        # such place).
42        self.info = info
43        self.doc = doc
44        self._ifcond = ifcond or []
45        self.features = features or []
46        self._checked = False
47
48    def c_name(self):
49        return c_name(self.name)
50
51    def check(self, schema):
52        assert not self._checked
53        seen = {}
54        for f in self.features:
55            f.check_clash(self.info, seen)
56        self._checked = True
57
58    def connect_doc(self, doc=None):
59        doc = doc or self.doc
60        if doc:
61            for f in self.features:
62                doc.connect_feature(f)
63
64    def check_doc(self):
65        if self.doc:
66            self.doc.check()
67
68    def _set_module(self, schema, info):
69        assert self._checked
70        self._module = schema.module_by_fname(info and info.fname)
71        self._module.add_entity(self)
72
73    def set_module(self, schema):
74        self._set_module(schema, self.info)
75
76    @property
77    def ifcond(self):
78        assert self._checked
79        return self._ifcond
80
81    def is_implicit(self):
82        return not self.info
83
84    def visit(self, visitor):
85        assert self._checked
86
87    def describe(self):
88        assert self.meta
89        return "%s '%s'" % (self.meta, self.name)
90
91
92class QAPISchemaVisitor:
93    def visit_begin(self, schema):
94        pass
95
96    def visit_end(self):
97        pass
98
99    def visit_module(self, name):
100        pass
101
102    def visit_needed(self, entity):
103        # Default to visiting everything
104        return True
105
106    def visit_include(self, name, info):
107        pass
108
109    def visit_builtin_type(self, name, info, json_type):
110        pass
111
112    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
113        pass
114
115    def visit_array_type(self, name, info, ifcond, element_type):
116        pass
117
118    def visit_object_type(self, name, info, ifcond, features,
119                          base, members, variants):
120        pass
121
122    def visit_object_type_flat(self, name, info, ifcond, features,
123                               members, variants):
124        pass
125
126    def visit_alternate_type(self, name, info, ifcond, features, variants):
127        pass
128
129    def visit_command(self, name, info, ifcond, features,
130                      arg_type, ret_type, gen, success_response, boxed,
131                      allow_oob, allow_preconfig):
132        pass
133
134    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
135        pass
136
137
138class QAPISchemaModule:
139    def __init__(self, name):
140        self.name = name
141        self._entity_list = []
142
143    def add_entity(self, ent):
144        self._entity_list.append(ent)
145
146    def visit(self, visitor):
147        visitor.visit_module(self.name)
148        for entity in self._entity_list:
149            if visitor.visit_needed(entity):
150                entity.visit(visitor)
151
152
153class QAPISchemaInclude(QAPISchemaEntity):
154    def __init__(self, sub_module, info):
155        super().__init__(None, info, None)
156        self._sub_module = sub_module
157
158    def visit(self, visitor):
159        super().visit(visitor)
160        visitor.visit_include(self._sub_module.name, self.info)
161
162
163class QAPISchemaType(QAPISchemaEntity):
164    # Return the C type for common use.
165    # For the types we commonly box, this is a pointer type.
166    def c_type(self):
167        pass
168
169    # Return the C type to be used in a parameter list.
170    def c_param_type(self):
171        return self.c_type()
172
173    # Return the C type to be used where we suppress boxing.
174    def c_unboxed_type(self):
175        return self.c_type()
176
177    def json_type(self):
178        pass
179
180    def alternate_qtype(self):
181        json2qtype = {
182            'null':    'QTYPE_QNULL',
183            'string':  'QTYPE_QSTRING',
184            'number':  'QTYPE_QNUM',
185            'int':     'QTYPE_QNUM',
186            'boolean': 'QTYPE_QBOOL',
187            'object':  'QTYPE_QDICT'
188        }
189        return json2qtype.get(self.json_type())
190
191    def doc_type(self):
192        if self.is_implicit():
193            return None
194        return self.name
195
196    def describe(self):
197        assert self.meta
198        return "%s type '%s'" % (self.meta, self.name)
199
200
201class QAPISchemaBuiltinType(QAPISchemaType):
202    meta = 'built-in'
203
204    def __init__(self, name, json_type, c_type):
205        super().__init__(name, None, None)
206        assert not c_type or isinstance(c_type, str)
207        assert json_type in ('string', 'number', 'int', 'boolean', 'null',
208                             'value')
209        self._json_type_name = json_type
210        self._c_type_name = c_type
211
212    def c_name(self):
213        return self.name
214
215    def c_type(self):
216        return self._c_type_name
217
218    def c_param_type(self):
219        if self.name == 'str':
220            return 'const ' + self._c_type_name
221        return self._c_type_name
222
223    def json_type(self):
224        return self._json_type_name
225
226    def doc_type(self):
227        return self.json_type()
228
229    def visit(self, visitor):
230        super().visit(visitor)
231        visitor.visit_builtin_type(self.name, self.info, self.json_type())
232
233
234class QAPISchemaEnumType(QAPISchemaType):
235    meta = 'enum'
236
237    def __init__(self, name, info, doc, ifcond, features, members, prefix):
238        super().__init__(name, info, doc, ifcond, features)
239        for m in members:
240            assert isinstance(m, QAPISchemaEnumMember)
241            m.set_defined_in(name)
242        assert prefix is None or isinstance(prefix, str)
243        self.members = members
244        self.prefix = prefix
245
246    def check(self, schema):
247        super().check(schema)
248        seen = {}
249        for m in self.members:
250            m.check_clash(self.info, seen)
251
252    def connect_doc(self, doc=None):
253        super().connect_doc(doc)
254        doc = doc or self.doc
255        for m in self.members:
256            m.connect_doc(doc)
257
258    def is_implicit(self):
259        # See QAPISchema._make_implicit_enum_type() and ._def_predefineds()
260        return self.name.endswith('Kind') or self.name == 'QType'
261
262    def c_type(self):
263        return c_name(self.name)
264
265    def member_names(self):
266        return [m.name for m in self.members]
267
268    def json_type(self):
269        return 'string'
270
271    def visit(self, visitor):
272        super().visit(visitor)
273        visitor.visit_enum_type(
274            self.name, self.info, self.ifcond, self.features,
275            self.members, self.prefix)
276
277
278class QAPISchemaArrayType(QAPISchemaType):
279    meta = 'array'
280
281    def __init__(self, name, info, element_type):
282        super().__init__(name, info, None)
283        assert isinstance(element_type, str)
284        self._element_type_name = element_type
285        self.element_type = None
286
287    def check(self, schema):
288        super().check(schema)
289        self.element_type = schema.resolve_type(
290            self._element_type_name, self.info,
291            self.info and self.info.defn_meta)
292        assert not isinstance(self.element_type, QAPISchemaArrayType)
293
294    def set_module(self, schema):
295        self._set_module(schema, self.element_type.info)
296
297    @property
298    def ifcond(self):
299        assert self._checked
300        return self.element_type.ifcond
301
302    def is_implicit(self):
303        return True
304
305    def c_type(self):
306        return c_name(self.name) + pointer_suffix
307
308    def json_type(self):
309        return 'array'
310
311    def doc_type(self):
312        elt_doc_type = self.element_type.doc_type()
313        if not elt_doc_type:
314            return None
315        return 'array of ' + elt_doc_type
316
317    def visit(self, visitor):
318        super().visit(visitor)
319        visitor.visit_array_type(self.name, self.info, self.ifcond,
320                                 self.element_type)
321
322    def describe(self):
323        assert self.meta
324        return "%s type ['%s']" % (self.meta, self._element_type_name)
325
326
327class QAPISchemaObjectType(QAPISchemaType):
328    def __init__(self, name, info, doc, ifcond, features,
329                 base, local_members, variants):
330        # struct has local_members, optional base, and no variants
331        # flat union has base, variants, and no local_members
332        # simple union has local_members, variants, and no base
333        super().__init__(name, info, doc, ifcond, features)
334        self.meta = 'union' if variants else 'struct'
335        assert base is None or isinstance(base, str)
336        for m in local_members:
337            assert isinstance(m, QAPISchemaObjectTypeMember)
338            m.set_defined_in(name)
339        if variants is not None:
340            assert isinstance(variants, QAPISchemaVariants)
341            variants.set_defined_in(name)
342        self._base_name = base
343        self.base = None
344        self.local_members = local_members
345        self.variants = variants
346        self.members = None
347
348    def check(self, schema):
349        # This calls another type T's .check() exactly when the C
350        # struct emitted by gen_object() contains that T's C struct
351        # (pointers don't count).
352        if self.members is not None:
353            # A previous .check() completed: nothing to do
354            return
355        if self._checked:
356            # Recursed: C struct contains itself
357            raise QAPISemError(self.info,
358                               "object %s contains itself" % self.name)
359
360        super().check(schema)
361        assert self._checked and self.members is None
362
363        seen = OrderedDict()
364        if self._base_name:
365            self.base = schema.resolve_type(self._base_name, self.info,
366                                            "'base'")
367            if (not isinstance(self.base, QAPISchemaObjectType)
368                    or self.base.variants):
369                raise QAPISemError(
370                    self.info,
371                    "'base' requires a struct type, %s isn't"
372                    % self.base.describe())
373            self.base.check(schema)
374            self.base.check_clash(self.info, seen)
375        for m in self.local_members:
376            m.check(schema)
377            m.check_clash(self.info, seen)
378        members = seen.values()
379
380        if self.variants:
381            self.variants.check(schema, seen)
382            self.variants.check_clash(self.info, seen)
383
384        self.members = members  # mark completed
385
386    # Check that the members of this type do not cause duplicate JSON members,
387    # and update seen to track the members seen so far. Report any errors
388    # on behalf of info, which is not necessarily self.info
389    def check_clash(self, info, seen):
390        assert self._checked
391        assert not self.variants       # not implemented
392        for m in self.members:
393            m.check_clash(info, seen)
394
395    def connect_doc(self, doc=None):
396        super().connect_doc(doc)
397        doc = doc or self.doc
398        if self.base and self.base.is_implicit():
399            self.base.connect_doc(doc)
400        for m in self.local_members:
401            m.connect_doc(doc)
402
403    @property
404    def ifcond(self):
405        assert self._checked
406        if isinstance(self._ifcond, QAPISchemaType):
407            # Simple union wrapper type inherits from wrapped type;
408            # see _make_implicit_object_type()
409            return self._ifcond.ifcond
410        return self._ifcond
411
412    def is_implicit(self):
413        # See QAPISchema._make_implicit_object_type(), as well as
414        # _def_predefineds()
415        return self.name.startswith('q_')
416
417    def is_empty(self):
418        assert self.members is not None
419        return not self.members and not self.variants
420
421    def c_name(self):
422        assert self.name != 'q_empty'
423        return super().c_name()
424
425    def c_type(self):
426        assert not self.is_implicit()
427        return c_name(self.name) + pointer_suffix
428
429    def c_unboxed_type(self):
430        return c_name(self.name)
431
432    def json_type(self):
433        return 'object'
434
435    def visit(self, visitor):
436        super().visit(visitor)
437        visitor.visit_object_type(
438            self.name, self.info, self.ifcond, self.features,
439            self.base, self.local_members, self.variants)
440        visitor.visit_object_type_flat(
441            self.name, self.info, self.ifcond, self.features,
442            self.members, self.variants)
443
444
445class QAPISchemaAlternateType(QAPISchemaType):
446    meta = 'alternate'
447
448    def __init__(self, name, info, doc, ifcond, features, variants):
449        super().__init__(name, info, doc, ifcond, features)
450        assert isinstance(variants, QAPISchemaVariants)
451        assert variants.tag_member
452        variants.set_defined_in(name)
453        variants.tag_member.set_defined_in(self.name)
454        self.variants = variants
455
456    def check(self, schema):
457        super().check(schema)
458        self.variants.tag_member.check(schema)
459        # Not calling self.variants.check_clash(), because there's nothing
460        # to clash with
461        self.variants.check(schema, {})
462        # Alternate branch names have no relation to the tag enum values;
463        # so we have to check for potential name collisions ourselves.
464        seen = {}
465        types_seen = {}
466        for v in self.variants.variants:
467            v.check_clash(self.info, seen)
468            qtype = v.type.alternate_qtype()
469            if not qtype:
470                raise QAPISemError(
471                    self.info,
472                    "%s cannot use %s"
473                    % (v.describe(self.info), v.type.describe()))
474            conflicting = set([qtype])
475            if qtype == 'QTYPE_QSTRING':
476                if isinstance(v.type, QAPISchemaEnumType):
477                    for m in v.type.members:
478                        if m.name in ['on', 'off']:
479                            conflicting.add('QTYPE_QBOOL')
480                        if re.match(r'[-+0-9.]', m.name):
481                            # lazy, could be tightened
482                            conflicting.add('QTYPE_QNUM')
483                else:
484                    conflicting.add('QTYPE_QNUM')
485                    conflicting.add('QTYPE_QBOOL')
486            for qt in conflicting:
487                if qt in types_seen:
488                    raise QAPISemError(
489                        self.info,
490                        "%s can't be distinguished from '%s'"
491                        % (v.describe(self.info), types_seen[qt]))
492                types_seen[qt] = v.name
493
494    def connect_doc(self, doc=None):
495        super().connect_doc(doc)
496        doc = doc or self.doc
497        for v in self.variants.variants:
498            v.connect_doc(doc)
499
500    def c_type(self):
501        return c_name(self.name) + pointer_suffix
502
503    def json_type(self):
504        return 'value'
505
506    def visit(self, visitor):
507        super().visit(visitor)
508        visitor.visit_alternate_type(
509            self.name, self.info, self.ifcond, self.features, self.variants)
510
511
512class QAPISchemaVariants:
513    def __init__(self, tag_name, info, tag_member, variants):
514        # Flat unions pass tag_name but not tag_member.
515        # Simple unions and alternates pass tag_member but not tag_name.
516        # After check(), tag_member is always set, and tag_name remains
517        # a reliable witness of being used by a flat union.
518        assert bool(tag_member) != bool(tag_name)
519        assert (isinstance(tag_name, str) or
520                isinstance(tag_member, QAPISchemaObjectTypeMember))
521        for v in variants:
522            assert isinstance(v, QAPISchemaVariant)
523        self._tag_name = tag_name
524        self.info = info
525        self.tag_member = tag_member
526        self.variants = variants
527
528    def set_defined_in(self, name):
529        for v in self.variants:
530            v.set_defined_in(name)
531
532    def check(self, schema, seen):
533        if not self.tag_member: # flat union
534            self.tag_member = seen.get(c_name(self._tag_name))
535            base = "'base'"
536            # Pointing to the base type when not implicit would be
537            # nice, but we don't know it here
538            if not self.tag_member or self._tag_name != self.tag_member.name:
539                raise QAPISemError(
540                    self.info,
541                    "discriminator '%s' is not a member of %s"
542                    % (self._tag_name, base))
543            # Here we do:
544            base_type = schema.lookup_type(self.tag_member.defined_in)
545            assert base_type
546            if not base_type.is_implicit():
547                base = "base type '%s'" % self.tag_member.defined_in
548            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
549                raise QAPISemError(
550                    self.info,
551                    "discriminator member '%s' of %s must be of enum type"
552                    % (self._tag_name, base))
553            if self.tag_member.optional:
554                raise QAPISemError(
555                    self.info,
556                    "discriminator member '%s' of %s must not be optional"
557                    % (self._tag_name, base))
558            if self.tag_member.ifcond:
559                raise QAPISemError(
560                    self.info,
561                    "discriminator member '%s' of %s must not be conditional"
562                    % (self._tag_name, base))
563        else:                   # simple union
564            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
565            assert not self.tag_member.optional
566            assert self.tag_member.ifcond == []
567        if self._tag_name:    # flat union
568            # branches that are not explicitly covered get an empty type
569            cases = {v.name for v in self.variants}
570            for m in self.tag_member.type.members:
571                if m.name not in cases:
572                    v = QAPISchemaVariant(m.name, self.info,
573                                          'q_empty', m.ifcond)
574                    v.set_defined_in(self.tag_member.defined_in)
575                    self.variants.append(v)
576        if not self.variants:
577            raise QAPISemError(self.info, "union has no branches")
578        for v in self.variants:
579            v.check(schema)
580            # Union names must match enum values; alternate names are
581            # checked separately. Use 'seen' to tell the two apart.
582            if seen:
583                if v.name not in self.tag_member.type.member_names():
584                    raise QAPISemError(
585                        self.info,
586                        "branch '%s' is not a value of %s"
587                        % (v.name, self.tag_member.type.describe()))
588                if (not isinstance(v.type, QAPISchemaObjectType)
589                        or v.type.variants):
590                    raise QAPISemError(
591                        self.info,
592                        "%s cannot use %s"
593                        % (v.describe(self.info), v.type.describe()))
594                v.type.check(schema)
595
596    def check_clash(self, info, seen):
597        for v in self.variants:
598            # Reset seen map for each variant, since qapi names from one
599            # branch do not affect another branch
600            v.type.check_clash(info, dict(seen))
601
602
603class QAPISchemaMember:
604    """ Represents object members, enum members and features """
605    role = 'member'
606
607    def __init__(self, name, info, ifcond=None):
608        assert isinstance(name, str)
609        self.name = name
610        self.info = info
611        self.ifcond = ifcond or []
612        self.defined_in = None
613
614    def set_defined_in(self, name):
615        assert not self.defined_in
616        self.defined_in = name
617
618    def check_clash(self, info, seen):
619        cname = c_name(self.name)
620        if cname in seen:
621            raise QAPISemError(
622                info,
623                "%s collides with %s"
624                % (self.describe(info), seen[cname].describe(info)))
625        seen[cname] = self
626
627    def connect_doc(self, doc):
628        if doc:
629            doc.connect_member(self)
630
631    def describe(self, info):
632        role = self.role
633        defined_in = self.defined_in
634        assert defined_in
635
636        if defined_in.startswith('q_obj_'):
637            # See QAPISchema._make_implicit_object_type() - reverse the
638            # mapping there to create a nice human-readable description
639            defined_in = defined_in[6:]
640            if defined_in.endswith('-arg'):
641                # Implicit type created for a command's dict 'data'
642                assert role == 'member'
643                role = 'parameter'
644            elif defined_in.endswith('-base'):
645                # Implicit type created for a flat union's dict 'base'
646                role = 'base ' + role
647            else:
648                # Implicit type created for a simple union's branch
649                assert defined_in.endswith('-wrapper')
650                # Unreachable and not implemented
651                assert False
652        elif defined_in.endswith('Kind'):
653            # See QAPISchema._make_implicit_enum_type()
654            # Implicit enum created for simple union's branches
655            assert role == 'value'
656            role = 'branch'
657        elif defined_in != info.defn_name:
658            return "%s '%s' of type '%s'" % (role, self.name, defined_in)
659        return "%s '%s'" % (role, self.name)
660
661
662class QAPISchemaEnumMember(QAPISchemaMember):
663    role = 'value'
664
665
666class QAPISchemaFeature(QAPISchemaMember):
667    role = 'feature'
668
669
670class QAPISchemaObjectTypeMember(QAPISchemaMember):
671    def __init__(self, name, info, typ, optional, ifcond=None, features=None):
672        super().__init__(name, info, ifcond)
673        assert isinstance(typ, str)
674        assert isinstance(optional, bool)
675        for f in features or []:
676            assert isinstance(f, QAPISchemaFeature)
677            f.set_defined_in(name)
678        self._type_name = typ
679        self.type = None
680        self.optional = optional
681        self.features = features or []
682
683    def check(self, schema):
684        assert self.defined_in
685        self.type = schema.resolve_type(self._type_name, self.info,
686                                        self.describe)
687        seen = {}
688        for f in self.features:
689            f.check_clash(self.info, seen)
690
691    def connect_doc(self, doc):
692        super().connect_doc(doc)
693        if doc:
694            for f in self.features:
695                doc.connect_feature(f)
696
697
698class QAPISchemaVariant(QAPISchemaObjectTypeMember):
699    role = 'branch'
700
701    def __init__(self, name, info, typ, ifcond=None):
702        super().__init__(name, info, typ, False, ifcond)
703
704
705class QAPISchemaCommand(QAPISchemaEntity):
706    meta = 'command'
707
708    def __init__(self, name, info, doc, ifcond, features,
709                 arg_type, ret_type,
710                 gen, success_response, boxed, allow_oob, allow_preconfig):
711        super().__init__(name, info, doc, ifcond, features)
712        assert not arg_type or isinstance(arg_type, str)
713        assert not ret_type or isinstance(ret_type, str)
714        self._arg_type_name = arg_type
715        self.arg_type = None
716        self._ret_type_name = ret_type
717        self.ret_type = None
718        self.gen = gen
719        self.success_response = success_response
720        self.boxed = boxed
721        self.allow_oob = allow_oob
722        self.allow_preconfig = allow_preconfig
723
724    def check(self, schema):
725        super().check(schema)
726        if self._arg_type_name:
727            self.arg_type = schema.resolve_type(
728                self._arg_type_name, self.info, "command's 'data'")
729            if not isinstance(self.arg_type, QAPISchemaObjectType):
730                raise QAPISemError(
731                    self.info,
732                    "command's 'data' cannot take %s"
733                    % self.arg_type.describe())
734            if self.arg_type.variants and not self.boxed:
735                raise QAPISemError(
736                    self.info,
737                    "command's 'data' can take %s only with 'boxed': true"
738                    % self.arg_type.describe())
739        if self._ret_type_name:
740            self.ret_type = schema.resolve_type(
741                self._ret_type_name, self.info, "command's 'returns'")
742            if self.name not in self.info.pragma.returns_whitelist:
743                typ = self.ret_type
744                if isinstance(typ, QAPISchemaArrayType):
745                    typ = self.ret_type.element_type
746                    assert typ
747                if not isinstance(typ, QAPISchemaObjectType):
748                    raise QAPISemError(
749                        self.info,
750                        "command's 'returns' cannot take %s"
751                        % self.ret_type.describe())
752
753    def connect_doc(self, doc=None):
754        super().connect_doc(doc)
755        doc = doc or self.doc
756        if doc:
757            if self.arg_type and self.arg_type.is_implicit():
758                self.arg_type.connect_doc(doc)
759
760    def visit(self, visitor):
761        super().visit(visitor)
762        visitor.visit_command(
763            self.name, self.info, self.ifcond, self.features,
764            self.arg_type, self.ret_type, self.gen, self.success_response,
765            self.boxed, self.allow_oob, self.allow_preconfig)
766
767
768class QAPISchemaEvent(QAPISchemaEntity):
769    meta = 'event'
770
771    def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
772        super().__init__(name, info, doc, ifcond, features)
773        assert not arg_type or isinstance(arg_type, str)
774        self._arg_type_name = arg_type
775        self.arg_type = None
776        self.boxed = boxed
777
778    def check(self, schema):
779        super().check(schema)
780        if self._arg_type_name:
781            self.arg_type = schema.resolve_type(
782                self._arg_type_name, self.info, "event's 'data'")
783            if not isinstance(self.arg_type, QAPISchemaObjectType):
784                raise QAPISemError(
785                    self.info,
786                    "event's 'data' cannot take %s"
787                    % self.arg_type.describe())
788            if self.arg_type.variants and not self.boxed:
789                raise QAPISemError(
790                    self.info,
791                    "event's 'data' can take %s only with 'boxed': true"
792                    % self.arg_type.describe())
793
794    def connect_doc(self, doc=None):
795        super().connect_doc(doc)
796        doc = doc or self.doc
797        if doc:
798            if self.arg_type and self.arg_type.is_implicit():
799                self.arg_type.connect_doc(doc)
800
801    def visit(self, visitor):
802        super().visit(visitor)
803        visitor.visit_event(
804            self.name, self.info, self.ifcond, self.features,
805            self.arg_type, self.boxed)
806
807
808class QAPISchema:
809    def __init__(self, fname):
810        self.fname = fname
811        parser = QAPISchemaParser(fname)
812        exprs = check_exprs(parser.exprs)
813        self.docs = parser.docs
814        self._entity_list = []
815        self._entity_dict = {}
816        self._module_dict = OrderedDict()
817        self._schema_dir = os.path.dirname(fname)
818        self._make_module(None) # built-ins
819        self._make_module(fname)
820        self._predefining = True
821        self._def_predefineds()
822        self._predefining = False
823        self._def_exprs(exprs)
824        self.check()
825
826    def _def_entity(self, ent):
827        # Only the predefined types are allowed to not have info
828        assert ent.info or self._predefining
829        self._entity_list.append(ent)
830        if ent.name is None:
831            return
832        # TODO reject names that differ only in '_' vs. '.'  vs. '-',
833        # because they're liable to clash in generated C.
834        other_ent = self._entity_dict.get(ent.name)
835        if other_ent:
836            if other_ent.info:
837                where = QAPIError(other_ent.info, None, "previous definition")
838                raise QAPISemError(
839                    ent.info,
840                    "'%s' is already defined\n%s" % (ent.name, where))
841            raise QAPISemError(
842                ent.info, "%s is already defined" % other_ent.describe())
843        self._entity_dict[ent.name] = ent
844
845    def lookup_entity(self, name, typ=None):
846        ent = self._entity_dict.get(name)
847        if typ and not isinstance(ent, typ):
848            return None
849        return ent
850
851    def lookup_type(self, name):
852        return self.lookup_entity(name, QAPISchemaType)
853
854    def resolve_type(self, name, info, what):
855        typ = self.lookup_type(name)
856        if not typ:
857            if callable(what):
858                what = what(info)
859            raise QAPISemError(
860                info, "%s uses unknown type '%s'" % (what, name))
861        return typ
862
863    def _module_name(self, fname):
864        if fname is None:
865            return None
866        return os.path.relpath(fname, self._schema_dir)
867
868    def _make_module(self, fname):
869        name = self._module_name(fname)
870        if name not in self._module_dict:
871            self._module_dict[name] = QAPISchemaModule(name)
872        return self._module_dict[name]
873
874    def module_by_fname(self, fname):
875        name = self._module_name(fname)
876        assert name in self._module_dict
877        return self._module_dict[name]
878
879    def _def_include(self, expr, info, doc):
880        include = expr['include']
881        assert doc is None
882        self._def_entity(QAPISchemaInclude(self._make_module(include), info))
883
884    def _def_builtin_type(self, name, json_type, c_type):
885        self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
886        # Instantiating only the arrays that are actually used would
887        # be nice, but we can't as long as their generated code
888        # (qapi-builtin-types.[ch]) may be shared by some other
889        # schema.
890        self._make_array_type(name, None)
891
892    def _def_predefineds(self):
893        for t in [('str',    'string',  'char' + pointer_suffix),
894                  ('number', 'number',  'double'),
895                  ('int',    'int',     'int64_t'),
896                  ('int8',   'int',     'int8_t'),
897                  ('int16',  'int',     'int16_t'),
898                  ('int32',  'int',     'int32_t'),
899                  ('int64',  'int',     'int64_t'),
900                  ('uint8',  'int',     'uint8_t'),
901                  ('uint16', 'int',     'uint16_t'),
902                  ('uint32', 'int',     'uint32_t'),
903                  ('uint64', 'int',     'uint64_t'),
904                  ('size',   'int',     'uint64_t'),
905                  ('bool',   'boolean', 'bool'),
906                  ('any',    'value',   'QObject' + pointer_suffix),
907                  ('null',   'null',    'QNull' + pointer_suffix)]:
908            self._def_builtin_type(*t)
909        self.the_empty_object_type = QAPISchemaObjectType(
910            'q_empty', None, None, None, None, None, [], None)
911        self._def_entity(self.the_empty_object_type)
912
913        qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
914                  'qbool']
915        qtype_values = self._make_enum_members(
916            [{'name': n} for n in qtypes], None)
917
918        self._def_entity(QAPISchemaEnumType('QType', None, None, None, None,
919                                            qtype_values, 'QTYPE'))
920
921    def _make_features(self, features, info):
922        if features is None:
923            return []
924        return [QAPISchemaFeature(f['name'], info, f.get('if'))
925                for f in features]
926
927    def _make_enum_members(self, values, info):
928        return [QAPISchemaEnumMember(v['name'], info, v.get('if'))
929                for v in values]
930
931    def _make_implicit_enum_type(self, name, info, ifcond, values):
932        # See also QAPISchemaObjectTypeMember.describe()
933        name = name + 'Kind'    # reserved by check_defn_name_str()
934        self._def_entity(QAPISchemaEnumType(
935            name, info, None, ifcond, None,
936            self._make_enum_members(values, info),
937            None))
938        return name
939
940    def _make_array_type(self, element_type, info):
941        name = element_type + 'List'    # reserved by check_defn_name_str()
942        if not self.lookup_type(name):
943            self._def_entity(QAPISchemaArrayType(name, info, element_type))
944        return name
945
946    def _make_implicit_object_type(self, name, info, ifcond, role, members):
947        if not members:
948            return None
949        # See also QAPISchemaObjectTypeMember.describe()
950        name = 'q_obj_%s-%s' % (name, role)
951        typ = self.lookup_entity(name, QAPISchemaObjectType)
952        if typ:
953            # The implicit object type has multiple users.  This can
954            # happen only for simple unions' implicit wrapper types.
955            # Its ifcond should be the disjunction of its user's
956            # ifconds.  Not implemented.  Instead, we always pass the
957            # wrapped type's ifcond, which is trivially the same for all
958            # users.  It's also necessary for the wrapper to compile.
959            # But it's not tight: the disjunction need not imply it.  We
960            # may end up compiling useless wrapper types.
961            # TODO kill simple unions or implement the disjunction
962            assert (ifcond or []) == typ._ifcond # pylint: disable=protected-access
963        else:
964            self._def_entity(QAPISchemaObjectType(
965                name, info, None, ifcond, None, None, members, None))
966        return name
967
968    def _def_enum_type(self, expr, info, doc):
969        name = expr['enum']
970        data = expr['data']
971        prefix = expr.get('prefix')
972        ifcond = expr.get('if')
973        features = self._make_features(expr.get('features'), info)
974        self._def_entity(QAPISchemaEnumType(
975            name, info, doc, ifcond, features,
976            self._make_enum_members(data, info), prefix))
977
978    def _make_member(self, name, typ, ifcond, features, info):
979        optional = False
980        if name.startswith('*'):
981            name = name[1:]
982            optional = True
983        if isinstance(typ, list):
984            assert len(typ) == 1
985            typ = self._make_array_type(typ[0], info)
986        return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond,
987                                          self._make_features(features, info))
988
989    def _make_members(self, data, info):
990        return [self._make_member(key, value['type'], value.get('if'),
991                                  value.get('features'), info)
992                for (key, value) in data.items()]
993
994    def _def_struct_type(self, expr, info, doc):
995        name = expr['struct']
996        base = expr.get('base')
997        data = expr['data']
998        ifcond = expr.get('if')
999        features = self._make_features(expr.get('features'), info)
1000        self._def_entity(QAPISchemaObjectType(
1001            name, info, doc, ifcond, features, base,
1002            self._make_members(data, info),
1003            None))
1004
1005    def _make_variant(self, case, typ, ifcond, info):
1006        return QAPISchemaVariant(case, info, typ, ifcond)
1007
1008    def _make_simple_variant(self, case, typ, ifcond, info):
1009        if isinstance(typ, list):
1010            assert len(typ) == 1
1011            typ = self._make_array_type(typ[0], info)
1012        typ = self._make_implicit_object_type(
1013            typ, info, self.lookup_type(typ),
1014            'wrapper', [self._make_member('data', typ, None, None, info)])
1015        return QAPISchemaVariant(case, info, typ, ifcond)
1016
1017    def _def_union_type(self, expr, info, doc):
1018        name = expr['union']
1019        data = expr['data']
1020        base = expr.get('base')
1021        ifcond = expr.get('if')
1022        features = self._make_features(expr.get('features'), info)
1023        tag_name = expr.get('discriminator')
1024        tag_member = None
1025        if isinstance(base, dict):
1026            base = self._make_implicit_object_type(
1027                name, info, ifcond,
1028                'base', self._make_members(base, info))
1029        if tag_name:
1030            variants = [self._make_variant(key, value['type'],
1031                                           value.get('if'), info)
1032                        for (key, value) in data.items()]
1033            members = []
1034        else:
1035            variants = [self._make_simple_variant(key, value['type'],
1036                                                  value.get('if'), info)
1037                        for (key, value) in data.items()]
1038            enum = [{'name': v.name, 'if': v.ifcond} for v in variants]
1039            typ = self._make_implicit_enum_type(name, info, ifcond, enum)
1040            tag_member = QAPISchemaObjectTypeMember('type', info, typ, False)
1041            members = [tag_member]
1042        self._def_entity(
1043            QAPISchemaObjectType(name, info, doc, ifcond, features,
1044                                 base, members,
1045                                 QAPISchemaVariants(
1046                                     tag_name, info, tag_member, variants)))
1047
1048    def _def_alternate_type(self, expr, info, doc):
1049        name = expr['alternate']
1050        data = expr['data']
1051        ifcond = expr.get('if')
1052        features = self._make_features(expr.get('features'), info)
1053        variants = [self._make_variant(key, value['type'], value.get('if'),
1054                                       info)
1055                    for (key, value) in data.items()]
1056        tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1057        self._def_entity(
1058            QAPISchemaAlternateType(name, info, doc, ifcond, features,
1059                                    QAPISchemaVariants(
1060                                        None, info, tag_member, variants)))
1061
1062    def _def_command(self, expr, info, doc):
1063        name = expr['command']
1064        data = expr.get('data')
1065        rets = expr.get('returns')
1066        gen = expr.get('gen', True)
1067        success_response = expr.get('success-response', True)
1068        boxed = expr.get('boxed', False)
1069        allow_oob = expr.get('allow-oob', False)
1070        allow_preconfig = expr.get('allow-preconfig', False)
1071        ifcond = expr.get('if')
1072        features = self._make_features(expr.get('features'), info)
1073        if isinstance(data, OrderedDict):
1074            data = self._make_implicit_object_type(
1075                name, info, ifcond,
1076                'arg', self._make_members(data, info))
1077        if isinstance(rets, list):
1078            assert len(rets) == 1
1079            rets = self._make_array_type(rets[0], info)
1080        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, features,
1081                                           data, rets,
1082                                           gen, success_response,
1083                                           boxed, allow_oob, allow_preconfig))
1084
1085    def _def_event(self, expr, info, doc):
1086        name = expr['event']
1087        data = expr.get('data')
1088        boxed = expr.get('boxed', False)
1089        ifcond = expr.get('if')
1090        features = self._make_features(expr.get('features'), info)
1091        if isinstance(data, OrderedDict):
1092            data = self._make_implicit_object_type(
1093                name, info, ifcond,
1094                'arg', self._make_members(data, info))
1095        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, features,
1096                                         data, boxed))
1097
1098    def _def_exprs(self, exprs):
1099        for expr_elem in exprs:
1100            expr = expr_elem['expr']
1101            info = expr_elem['info']
1102            doc = expr_elem.get('doc')
1103            if 'enum' in expr:
1104                self._def_enum_type(expr, info, doc)
1105            elif 'struct' in expr:
1106                self._def_struct_type(expr, info, doc)
1107            elif 'union' in expr:
1108                self._def_union_type(expr, info, doc)
1109            elif 'alternate' in expr:
1110                self._def_alternate_type(expr, info, doc)
1111            elif 'command' in expr:
1112                self._def_command(expr, info, doc)
1113            elif 'event' in expr:
1114                self._def_event(expr, info, doc)
1115            elif 'include' in expr:
1116                self._def_include(expr, info, doc)
1117            else:
1118                assert False
1119
1120    def check(self):
1121        for ent in self._entity_list:
1122            ent.check(self)
1123            ent.connect_doc()
1124            ent.check_doc()
1125        for ent in self._entity_list:
1126            ent.set_module(self)
1127
1128    def visit(self, visitor):
1129        visitor.visit_begin(self)
1130        for mod in self._module_dict.values():
1131            mod.visit(visitor)
1132        visitor.visit_end()
1133