xref: /openbmc/qemu/scripts/qapi/schema.py (revision 226b5be6d434a3f139436d19227121266d8729d2)
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        if doc:
256            for m in self.members:
257                doc.connect_member(m)
258
259    def is_implicit(self):
260        # See QAPISchema._make_implicit_enum_type() and ._def_predefineds()
261        return self.name.endswith('Kind') or self.name == 'QType'
262
263    def c_type(self):
264        return c_name(self.name)
265
266    def member_names(self):
267        return [m.name for m in self.members]
268
269    def json_type(self):
270        return 'string'
271
272    def visit(self, visitor):
273        super().visit(visitor)
274        visitor.visit_enum_type(
275            self.name, self.info, self.ifcond, self.features,
276            self.members, self.prefix)
277
278
279class QAPISchemaArrayType(QAPISchemaType):
280    meta = 'array'
281
282    def __init__(self, name, info, element_type):
283        super().__init__(name, info, None)
284        assert isinstance(element_type, str)
285        self._element_type_name = element_type
286        self.element_type = None
287
288    def check(self, schema):
289        super().check(schema)
290        self.element_type = schema.resolve_type(
291            self._element_type_name, self.info,
292            self.info and self.info.defn_meta)
293        assert not isinstance(self.element_type, QAPISchemaArrayType)
294
295    def set_module(self, schema):
296        self._set_module(schema, self.element_type.info)
297
298    @property
299    def ifcond(self):
300        assert self._checked
301        return self.element_type.ifcond
302
303    def is_implicit(self):
304        return True
305
306    def c_type(self):
307        return c_name(self.name) + pointer_suffix
308
309    def json_type(self):
310        return 'array'
311
312    def doc_type(self):
313        elt_doc_type = self.element_type.doc_type()
314        if not elt_doc_type:
315            return None
316        return 'array of ' + elt_doc_type
317
318    def visit(self, visitor):
319        super().visit(visitor)
320        visitor.visit_array_type(self.name, self.info, self.ifcond,
321                                 self.element_type)
322
323    def describe(self):
324        assert self.meta
325        return "%s type ['%s']" % (self.meta, self._element_type_name)
326
327
328class QAPISchemaObjectType(QAPISchemaType):
329    def __init__(self, name, info, doc, ifcond, features,
330                 base, local_members, variants):
331        # struct has local_members, optional base, and no variants
332        # flat union has base, variants, and no local_members
333        # simple union has local_members, variants, and no base
334        super().__init__(name, info, doc, ifcond, features)
335        self.meta = 'union' if variants else 'struct'
336        assert base is None or isinstance(base, str)
337        for m in local_members:
338            assert isinstance(m, QAPISchemaObjectTypeMember)
339            m.set_defined_in(name)
340        if variants is not None:
341            assert isinstance(variants, QAPISchemaObjectTypeVariants)
342            variants.set_defined_in(name)
343        self._base_name = base
344        self.base = None
345        self.local_members = local_members
346        self.variants = variants
347        self.members = None
348
349    def check(self, schema):
350        # This calls another type T's .check() exactly when the C
351        # struct emitted by gen_object() contains that T's C struct
352        # (pointers don't count).
353        if self.members is not None:
354            # A previous .check() completed: nothing to do
355            return
356        if self._checked:
357            # Recursed: C struct contains itself
358            raise QAPISemError(self.info,
359                               "object %s contains itself" % self.name)
360
361        super().check(schema)
362        assert self._checked and self.members is None
363
364        seen = OrderedDict()
365        if self._base_name:
366            self.base = schema.resolve_type(self._base_name, self.info,
367                                            "'base'")
368            if (not isinstance(self.base, QAPISchemaObjectType)
369                    or self.base.variants):
370                raise QAPISemError(
371                    self.info,
372                    "'base' requires a struct type, %s isn't"
373                    % self.base.describe())
374            self.base.check(schema)
375            self.base.check_clash(self.info, seen)
376        for m in self.local_members:
377            m.check(schema)
378            m.check_clash(self.info, seen)
379        members = seen.values()
380
381        if self.variants:
382            self.variants.check(schema, seen)
383            self.variants.check_clash(self.info, seen)
384
385        self.members = members  # mark completed
386
387    # Check that the members of this type do not cause duplicate JSON members,
388    # and update seen to track the members seen so far. Report any errors
389    # on behalf of info, which is not necessarily self.info
390    def check_clash(self, info, seen):
391        assert self._checked
392        assert not self.variants       # not implemented
393        for m in self.members:
394            m.check_clash(info, seen)
395
396    def connect_doc(self, doc=None):
397        super().connect_doc(doc)
398        doc = doc or self.doc
399        if doc:
400            if self.base and self.base.is_implicit():
401                self.base.connect_doc(doc)
402            for m in self.local_members:
403                doc.connect_member(m)
404
405    @property
406    def ifcond(self):
407        assert self._checked
408        if isinstance(self._ifcond, QAPISchemaType):
409            # Simple union wrapper type inherits from wrapped type;
410            # see _make_implicit_object_type()
411            return self._ifcond.ifcond
412        return self._ifcond
413
414    def is_implicit(self):
415        # See QAPISchema._make_implicit_object_type(), as well as
416        # _def_predefineds()
417        return self.name.startswith('q_')
418
419    def is_empty(self):
420        assert self.members is not None
421        return not self.members and not self.variants
422
423    def c_name(self):
424        assert self.name != 'q_empty'
425        return super().c_name()
426
427    def c_type(self):
428        assert not self.is_implicit()
429        return c_name(self.name) + pointer_suffix
430
431    def c_unboxed_type(self):
432        return c_name(self.name)
433
434    def json_type(self):
435        return 'object'
436
437    def visit(self, visitor):
438        super().visit(visitor)
439        visitor.visit_object_type(
440            self.name, self.info, self.ifcond, self.features,
441            self.base, self.local_members, self.variants)
442        visitor.visit_object_type_flat(
443            self.name, self.info, self.ifcond, self.features,
444            self.members, self.variants)
445
446
447class QAPISchemaAlternateType(QAPISchemaType):
448    meta = 'alternate'
449
450    def __init__(self, name, info, doc, ifcond, features, variants):
451        super().__init__(name, info, doc, ifcond, features)
452        assert isinstance(variants, QAPISchemaObjectTypeVariants)
453        assert variants.tag_member
454        variants.set_defined_in(name)
455        variants.tag_member.set_defined_in(self.name)
456        self.variants = variants
457
458    def check(self, schema):
459        super().check(schema)
460        self.variants.tag_member.check(schema)
461        # Not calling self.variants.check_clash(), because there's nothing
462        # to clash with
463        self.variants.check(schema, {})
464        # Alternate branch names have no relation to the tag enum values;
465        # so we have to check for potential name collisions ourselves.
466        seen = {}
467        types_seen = {}
468        for v in self.variants.variants:
469            v.check_clash(self.info, seen)
470            qtype = v.type.alternate_qtype()
471            if not qtype:
472                raise QAPISemError(
473                    self.info,
474                    "%s cannot use %s"
475                    % (v.describe(self.info), v.type.describe()))
476            conflicting = set([qtype])
477            if qtype == 'QTYPE_QSTRING':
478                if isinstance(v.type, QAPISchemaEnumType):
479                    for m in v.type.members:
480                        if m.name in ['on', 'off']:
481                            conflicting.add('QTYPE_QBOOL')
482                        if re.match(r'[-+0-9.]', m.name):
483                            # lazy, could be tightened
484                            conflicting.add('QTYPE_QNUM')
485                else:
486                    conflicting.add('QTYPE_QNUM')
487                    conflicting.add('QTYPE_QBOOL')
488            for qt in conflicting:
489                if qt in types_seen:
490                    raise QAPISemError(
491                        self.info,
492                        "%s can't be distinguished from '%s'"
493                        % (v.describe(self.info), types_seen[qt]))
494                types_seen[qt] = v.name
495
496    def connect_doc(self, doc=None):
497        super().connect_doc(doc)
498        doc = doc or self.doc
499        if doc:
500            for v in self.variants.variants:
501                doc.connect_member(v)
502
503    def c_type(self):
504        return c_name(self.name) + pointer_suffix
505
506    def json_type(self):
507        return 'value'
508
509    def visit(self, visitor):
510        super().visit(visitor)
511        visitor.visit_alternate_type(
512            self.name, self.info, self.ifcond, self.features, self.variants)
513
514
515class QAPISchemaObjectTypeVariants:
516    def __init__(self, tag_name, info, tag_member, variants):
517        # Flat unions pass tag_name but not tag_member.
518        # Simple unions and alternates pass tag_member but not tag_name.
519        # After check(), tag_member is always set, and tag_name remains
520        # a reliable witness of being used by a flat union.
521        assert bool(tag_member) != bool(tag_name)
522        assert (isinstance(tag_name, str) or
523                isinstance(tag_member, QAPISchemaObjectTypeMember))
524        for v in variants:
525            assert isinstance(v, QAPISchemaObjectTypeVariant)
526        self._tag_name = tag_name
527        self.info = info
528        self.tag_member = tag_member
529        self.variants = variants
530
531    def set_defined_in(self, name):
532        for v in self.variants:
533            v.set_defined_in(name)
534
535    def check(self, schema, seen):
536        if not self.tag_member: # flat union
537            self.tag_member = seen.get(c_name(self._tag_name))
538            base = "'base'"
539            # Pointing to the base type when not implicit would be
540            # nice, but we don't know it here
541            if not self.tag_member or self._tag_name != self.tag_member.name:
542                raise QAPISemError(
543                    self.info,
544                    "discriminator '%s' is not a member of %s"
545                    % (self._tag_name, base))
546            # Here we do:
547            base_type = schema.lookup_type(self.tag_member.defined_in)
548            assert base_type
549            if not base_type.is_implicit():
550                base = "base type '%s'" % self.tag_member.defined_in
551            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
552                raise QAPISemError(
553                    self.info,
554                    "discriminator member '%s' of %s must be of enum type"
555                    % (self._tag_name, base))
556            if self.tag_member.optional:
557                raise QAPISemError(
558                    self.info,
559                    "discriminator member '%s' of %s must not be optional"
560                    % (self._tag_name, base))
561            if self.tag_member.ifcond:
562                raise QAPISemError(
563                    self.info,
564                    "discriminator member '%s' of %s must not be conditional"
565                    % (self._tag_name, base))
566        else:                   # simple union
567            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
568            assert not self.tag_member.optional
569            assert self.tag_member.ifcond == []
570        if self._tag_name:    # flat union
571            # branches that are not explicitly covered get an empty type
572            cases = {v.name for v in self.variants}
573            for m in self.tag_member.type.members:
574                if m.name not in cases:
575                    v = QAPISchemaObjectTypeVariant(m.name, self.info,
576                                                    'q_empty', m.ifcond)
577                    v.set_defined_in(self.tag_member.defined_in)
578                    self.variants.append(v)
579        if not self.variants:
580            raise QAPISemError(self.info, "union has no branches")
581        for v in self.variants:
582            v.check(schema)
583            # Union names must match enum values; alternate names are
584            # checked separately. Use 'seen' to tell the two apart.
585            if seen:
586                if v.name not in self.tag_member.type.member_names():
587                    raise QAPISemError(
588                        self.info,
589                        "branch '%s' is not a value of %s"
590                        % (v.name, self.tag_member.type.describe()))
591                if (not isinstance(v.type, QAPISchemaObjectType)
592                        or v.type.variants):
593                    raise QAPISemError(
594                        self.info,
595                        "%s cannot use %s"
596                        % (v.describe(self.info), v.type.describe()))
597                v.type.check(schema)
598
599    def check_clash(self, info, seen):
600        for v in self.variants:
601            # Reset seen map for each variant, since qapi names from one
602            # branch do not affect another branch
603            v.type.check_clash(info, dict(seen))
604
605
606class QAPISchemaMember:
607    """ Represents object members, enum members and features """
608    role = 'member'
609
610    def __init__(self, name, info, ifcond=None):
611        assert isinstance(name, str)
612        self.name = name
613        self.info = info
614        self.ifcond = ifcond or []
615        self.defined_in = None
616
617    def set_defined_in(self, name):
618        assert not self.defined_in
619        self.defined_in = name
620
621    def check_clash(self, info, seen):
622        cname = c_name(self.name)
623        if cname in seen:
624            raise QAPISemError(
625                info,
626                "%s collides with %s"
627                % (self.describe(info), seen[cname].describe(info)))
628        seen[cname] = self
629
630    def describe(self, info):
631        role = self.role
632        defined_in = self.defined_in
633        assert defined_in
634
635        if defined_in.startswith('q_obj_'):
636            # See QAPISchema._make_implicit_object_type() - reverse the
637            # mapping there to create a nice human-readable description
638            defined_in = defined_in[6:]
639            if defined_in.endswith('-arg'):
640                # Implicit type created for a command's dict 'data'
641                assert role == 'member'
642                role = 'parameter'
643            elif defined_in.endswith('-base'):
644                # Implicit type created for a flat union's dict 'base'
645                role = 'base ' + role
646            else:
647                # Implicit type created for a simple union's branch
648                assert defined_in.endswith('-wrapper')
649                # Unreachable and not implemented
650                assert False
651        elif defined_in.endswith('Kind'):
652            # See QAPISchema._make_implicit_enum_type()
653            # Implicit enum created for simple union's branches
654            assert role == 'value'
655            role = 'branch'
656        elif defined_in != info.defn_name:
657            return "%s '%s' of type '%s'" % (role, self.name, defined_in)
658        return "%s '%s'" % (role, self.name)
659
660
661class QAPISchemaEnumMember(QAPISchemaMember):
662    role = 'value'
663
664
665class QAPISchemaFeature(QAPISchemaMember):
666    role = 'feature'
667
668
669class QAPISchemaObjectTypeMember(QAPISchemaMember):
670    def __init__(self, name, info, typ, optional, ifcond=None):
671        super().__init__(name, info, ifcond)
672        assert isinstance(typ, str)
673        assert isinstance(optional, bool)
674        self._type_name = typ
675        self.type = None
676        self.optional = optional
677
678    def check(self, schema):
679        assert self.defined_in
680        self.type = schema.resolve_type(self._type_name, self.info,
681                                        self.describe)
682
683
684class QAPISchemaObjectTypeVariant(QAPISchemaObjectTypeMember):
685    role = 'branch'
686
687    def __init__(self, name, info, typ, ifcond=None):
688        super().__init__(name, info, typ, False, ifcond)
689
690
691class QAPISchemaCommand(QAPISchemaEntity):
692    meta = 'command'
693
694    def __init__(self, name, info, doc, ifcond, features,
695                 arg_type, ret_type,
696                 gen, success_response, boxed, allow_oob, allow_preconfig):
697        super().__init__(name, info, doc, ifcond, features)
698        assert not arg_type or isinstance(arg_type, str)
699        assert not ret_type or isinstance(ret_type, str)
700        self._arg_type_name = arg_type
701        self.arg_type = None
702        self._ret_type_name = ret_type
703        self.ret_type = None
704        self.gen = gen
705        self.success_response = success_response
706        self.boxed = boxed
707        self.allow_oob = allow_oob
708        self.allow_preconfig = allow_preconfig
709
710    def check(self, schema):
711        super().check(schema)
712        if self._arg_type_name:
713            self.arg_type = schema.resolve_type(
714                self._arg_type_name, self.info, "command's 'data'")
715            if not isinstance(self.arg_type, QAPISchemaObjectType):
716                raise QAPISemError(
717                    self.info,
718                    "command's 'data' cannot take %s"
719                    % self.arg_type.describe())
720            if self.arg_type.variants and not self.boxed:
721                raise QAPISemError(
722                    self.info,
723                    "command's 'data' can take %s only with 'boxed': true"
724                    % self.arg_type.describe())
725        if self._ret_type_name:
726            self.ret_type = schema.resolve_type(
727                self._ret_type_name, self.info, "command's 'returns'")
728            if self.name not in self.info.pragma.returns_whitelist:
729                typ = self.ret_type
730                if isinstance(typ, QAPISchemaArrayType):
731                    typ = self.ret_type.element_type
732                    assert typ
733                if not isinstance(typ, QAPISchemaObjectType):
734                    raise QAPISemError(
735                        self.info,
736                        "command's 'returns' cannot take %s"
737                        % self.ret_type.describe())
738
739    def connect_doc(self, doc=None):
740        super().connect_doc(doc)
741        doc = doc or self.doc
742        if doc:
743            if self.arg_type and self.arg_type.is_implicit():
744                self.arg_type.connect_doc(doc)
745
746    def visit(self, visitor):
747        super().visit(visitor)
748        visitor.visit_command(
749            self.name, self.info, self.ifcond, self.features,
750            self.arg_type, self.ret_type, self.gen, self.success_response,
751            self.boxed, self.allow_oob, self.allow_preconfig)
752
753
754class QAPISchemaEvent(QAPISchemaEntity):
755    meta = 'event'
756
757    def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
758        super().__init__(name, info, doc, ifcond, features)
759        assert not arg_type or isinstance(arg_type, str)
760        self._arg_type_name = arg_type
761        self.arg_type = None
762        self.boxed = boxed
763
764    def check(self, schema):
765        super().check(schema)
766        if self._arg_type_name:
767            self.arg_type = schema.resolve_type(
768                self._arg_type_name, self.info, "event's 'data'")
769            if not isinstance(self.arg_type, QAPISchemaObjectType):
770                raise QAPISemError(
771                    self.info,
772                    "event's 'data' cannot take %s"
773                    % self.arg_type.describe())
774            if self.arg_type.variants and not self.boxed:
775                raise QAPISemError(
776                    self.info,
777                    "event's 'data' can take %s only with 'boxed': true"
778                    % self.arg_type.describe())
779
780    def connect_doc(self, doc=None):
781        super().connect_doc(doc)
782        doc = doc or self.doc
783        if doc:
784            if self.arg_type and self.arg_type.is_implicit():
785                self.arg_type.connect_doc(doc)
786
787    def visit(self, visitor):
788        super().visit(visitor)
789        visitor.visit_event(
790            self.name, self.info, self.ifcond, self.features,
791            self.arg_type, self.boxed)
792
793
794class QAPISchema:
795    def __init__(self, fname):
796        self.fname = fname
797        parser = QAPISchemaParser(fname)
798        exprs = check_exprs(parser.exprs)
799        self.docs = parser.docs
800        self._entity_list = []
801        self._entity_dict = {}
802        self._module_dict = OrderedDict()
803        self._schema_dir = os.path.dirname(fname)
804        self._make_module(None) # built-ins
805        self._make_module(fname)
806        self._predefining = True
807        self._def_predefineds()
808        self._predefining = False
809        self._def_exprs(exprs)
810        self.check()
811
812    def _def_entity(self, ent):
813        # Only the predefined types are allowed to not have info
814        assert ent.info or self._predefining
815        self._entity_list.append(ent)
816        if ent.name is None:
817            return
818        # TODO reject names that differ only in '_' vs. '.'  vs. '-',
819        # because they're liable to clash in generated C.
820        other_ent = self._entity_dict.get(ent.name)
821        if other_ent:
822            if other_ent.info:
823                where = QAPIError(other_ent.info, None, "previous definition")
824                raise QAPISemError(
825                    ent.info,
826                    "'%s' is already defined\n%s" % (ent.name, where))
827            raise QAPISemError(
828                ent.info, "%s is already defined" % other_ent.describe())
829        self._entity_dict[ent.name] = ent
830
831    def lookup_entity(self, name, typ=None):
832        ent = self._entity_dict.get(name)
833        if typ and not isinstance(ent, typ):
834            return None
835        return ent
836
837    def lookup_type(self, name):
838        return self.lookup_entity(name, QAPISchemaType)
839
840    def resolve_type(self, name, info, what):
841        typ = self.lookup_type(name)
842        if not typ:
843            if callable(what):
844                what = what(info)
845            raise QAPISemError(
846                info, "%s uses unknown type '%s'" % (what, name))
847        return typ
848
849    def _module_name(self, fname):
850        if fname is None:
851            return None
852        return os.path.relpath(fname, self._schema_dir)
853
854    def _make_module(self, fname):
855        name = self._module_name(fname)
856        if name not in self._module_dict:
857            self._module_dict[name] = QAPISchemaModule(name)
858        return self._module_dict[name]
859
860    def module_by_fname(self, fname):
861        name = self._module_name(fname)
862        assert name in self._module_dict
863        return self._module_dict[name]
864
865    def _def_include(self, expr, info, doc):
866        include = expr['include']
867        assert doc is None
868        self._def_entity(QAPISchemaInclude(self._make_module(include), info))
869
870    def _def_builtin_type(self, name, json_type, c_type):
871        self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
872        # Instantiating only the arrays that are actually used would
873        # be nice, but we can't as long as their generated code
874        # (qapi-builtin-types.[ch]) may be shared by some other
875        # schema.
876        self._make_array_type(name, None)
877
878    def _def_predefineds(self):
879        for t in [('str',    'string',  'char' + pointer_suffix),
880                  ('number', 'number',  'double'),
881                  ('int',    'int',     'int64_t'),
882                  ('int8',   'int',     'int8_t'),
883                  ('int16',  'int',     'int16_t'),
884                  ('int32',  'int',     'int32_t'),
885                  ('int64',  'int',     'int64_t'),
886                  ('uint8',  'int',     'uint8_t'),
887                  ('uint16', 'int',     'uint16_t'),
888                  ('uint32', 'int',     'uint32_t'),
889                  ('uint64', 'int',     'uint64_t'),
890                  ('size',   'int',     'uint64_t'),
891                  ('bool',   'boolean', 'bool'),
892                  ('any',    'value',   'QObject' + pointer_suffix),
893                  ('null',   'null',    'QNull' + pointer_suffix)]:
894            self._def_builtin_type(*t)
895        self.the_empty_object_type = QAPISchemaObjectType(
896            'q_empty', None, None, None, None, None, [], None)
897        self._def_entity(self.the_empty_object_type)
898
899        qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
900                  'qbool']
901        qtype_values = self._make_enum_members(
902            [{'name': n} for n in qtypes], None)
903
904        self._def_entity(QAPISchemaEnumType('QType', None, None, None, None,
905                                            qtype_values, 'QTYPE'))
906
907    def _make_features(self, features, info):
908        if features is None:
909            return []
910        return [QAPISchemaFeature(f['name'], info, f.get('if'))
911                for f in features]
912
913    def _make_enum_members(self, values, info):
914        return [QAPISchemaEnumMember(v['name'], info, v.get('if'))
915                for v in values]
916
917    def _make_implicit_enum_type(self, name, info, ifcond, values):
918        # See also QAPISchemaObjectTypeMember.describe()
919        name = name + 'Kind'    # reserved by check_defn_name_str()
920        self._def_entity(QAPISchemaEnumType(
921            name, info, None, ifcond, None,
922            self._make_enum_members(values, info),
923            None))
924        return name
925
926    def _make_array_type(self, element_type, info):
927        name = element_type + 'List'    # reserved by check_defn_name_str()
928        if not self.lookup_type(name):
929            self._def_entity(QAPISchemaArrayType(name, info, element_type))
930        return name
931
932    def _make_implicit_object_type(self, name, info, ifcond, role, members):
933        if not members:
934            return None
935        # See also QAPISchemaObjectTypeMember.describe()
936        name = 'q_obj_%s-%s' % (name, role)
937        typ = self.lookup_entity(name, QAPISchemaObjectType)
938        if typ:
939            # The implicit object type has multiple users.  This can
940            # happen only for simple unions' implicit wrapper types.
941            # Its ifcond should be the disjunction of its user's
942            # ifconds.  Not implemented.  Instead, we always pass the
943            # wrapped type's ifcond, which is trivially the same for all
944            # users.  It's also necessary for the wrapper to compile.
945            # But it's not tight: the disjunction need not imply it.  We
946            # may end up compiling useless wrapper types.
947            # TODO kill simple unions or implement the disjunction
948            assert (ifcond or []) == typ._ifcond # pylint: disable=protected-access
949        else:
950            self._def_entity(QAPISchemaObjectType(
951                name, info, None, ifcond, None, None, members, None))
952        return name
953
954    def _def_enum_type(self, expr, info, doc):
955        name = expr['enum']
956        data = expr['data']
957        prefix = expr.get('prefix')
958        ifcond = expr.get('if')
959        features = self._make_features(expr.get('features'), info)
960        self._def_entity(QAPISchemaEnumType(
961            name, info, doc, ifcond, features,
962            self._make_enum_members(data, info), prefix))
963
964    def _make_member(self, name, typ, ifcond, info):
965        optional = False
966        if name.startswith('*'):
967            name = name[1:]
968            optional = True
969        if isinstance(typ, list):
970            assert len(typ) == 1
971            typ = self._make_array_type(typ[0], info)
972        return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond)
973
974    def _make_members(self, data, info):
975        return [self._make_member(key, value['type'], value.get('if'), info)
976                for (key, value) in data.items()]
977
978    def _def_struct_type(self, expr, info, doc):
979        name = expr['struct']
980        base = expr.get('base')
981        data = expr['data']
982        ifcond = expr.get('if')
983        features = self._make_features(expr.get('features'), info)
984        self._def_entity(QAPISchemaObjectType(
985            name, info, doc, ifcond, features, base,
986            self._make_members(data, info),
987            None))
988
989    def _make_variant(self, case, typ, ifcond, info):
990        return QAPISchemaObjectTypeVariant(case, info, typ, ifcond)
991
992    def _make_simple_variant(self, case, typ, ifcond, info):
993        if isinstance(typ, list):
994            assert len(typ) == 1
995            typ = self._make_array_type(typ[0], info)
996        typ = self._make_implicit_object_type(
997            typ, info, self.lookup_type(typ),
998            'wrapper', [self._make_member('data', typ, None, info)])
999        return QAPISchemaObjectTypeVariant(case, info, typ, ifcond)
1000
1001    def _def_union_type(self, expr, info, doc):
1002        name = expr['union']
1003        data = expr['data']
1004        base = expr.get('base')
1005        ifcond = expr.get('if')
1006        features = self._make_features(expr.get('features'), info)
1007        tag_name = expr.get('discriminator')
1008        tag_member = None
1009        if isinstance(base, dict):
1010            base = self._make_implicit_object_type(
1011                name, info, ifcond,
1012                'base', self._make_members(base, info))
1013        if tag_name:
1014            variants = [self._make_variant(key, value['type'],
1015                                           value.get('if'), info)
1016                        for (key, value) in data.items()]
1017            members = []
1018        else:
1019            variants = [self._make_simple_variant(key, value['type'],
1020                                                  value.get('if'), info)
1021                        for (key, value) in data.items()]
1022            enum = [{'name': v.name, 'if': v.ifcond} for v in variants]
1023            typ = self._make_implicit_enum_type(name, info, ifcond, enum)
1024            tag_member = QAPISchemaObjectTypeMember('type', info, typ, False)
1025            members = [tag_member]
1026        self._def_entity(
1027            QAPISchemaObjectType(name, info, doc, ifcond, features,
1028                                 base, members,
1029                                 QAPISchemaObjectTypeVariants(
1030                                     tag_name, info, tag_member, variants)))
1031
1032    def _def_alternate_type(self, expr, info, doc):
1033        name = expr['alternate']
1034        data = expr['data']
1035        ifcond = expr.get('if')
1036        features = self._make_features(expr.get('features'), info)
1037        variants = [self._make_variant(key, value['type'], value.get('if'),
1038                                       info)
1039                    for (key, value) in data.items()]
1040        tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1041        self._def_entity(
1042            QAPISchemaAlternateType(name, info, doc, ifcond, features,
1043                                    QAPISchemaObjectTypeVariants(
1044                                        None, info, tag_member, variants)))
1045
1046    def _def_command(self, expr, info, doc):
1047        name = expr['command']
1048        data = expr.get('data')
1049        rets = expr.get('returns')
1050        gen = expr.get('gen', True)
1051        success_response = expr.get('success-response', True)
1052        boxed = expr.get('boxed', False)
1053        allow_oob = expr.get('allow-oob', False)
1054        allow_preconfig = expr.get('allow-preconfig', False)
1055        ifcond = expr.get('if')
1056        features = self._make_features(expr.get('features'), info)
1057        if isinstance(data, OrderedDict):
1058            data = self._make_implicit_object_type(
1059                name, info, ifcond,
1060                'arg', self._make_members(data, info))
1061        if isinstance(rets, list):
1062            assert len(rets) == 1
1063            rets = self._make_array_type(rets[0], info)
1064        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, features,
1065                                           data, rets,
1066                                           gen, success_response,
1067                                           boxed, allow_oob, allow_preconfig))
1068
1069    def _def_event(self, expr, info, doc):
1070        name = expr['event']
1071        data = expr.get('data')
1072        boxed = expr.get('boxed', False)
1073        ifcond = expr.get('if')
1074        features = self._make_features(expr.get('features'), info)
1075        if isinstance(data, OrderedDict):
1076            data = self._make_implicit_object_type(
1077                name, info, ifcond,
1078                'arg', self._make_members(data, info))
1079        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, features,
1080                                         data, boxed))
1081
1082    def _def_exprs(self, exprs):
1083        for expr_elem in exprs:
1084            expr = expr_elem['expr']
1085            info = expr_elem['info']
1086            doc = expr_elem.get('doc')
1087            if 'enum' in expr:
1088                self._def_enum_type(expr, info, doc)
1089            elif 'struct' in expr:
1090                self._def_struct_type(expr, info, doc)
1091            elif 'union' in expr:
1092                self._def_union_type(expr, info, doc)
1093            elif 'alternate' in expr:
1094                self._def_alternate_type(expr, info, doc)
1095            elif 'command' in expr:
1096                self._def_command(expr, info, doc)
1097            elif 'event' in expr:
1098                self._def_event(expr, info, doc)
1099            elif 'include' in expr:
1100                self._def_include(expr, info, doc)
1101            else:
1102                assert False
1103
1104    def check(self):
1105        for ent in self._entity_list:
1106            ent.check(self)
1107            ent.connect_doc()
1108            ent.check_doc()
1109        for ent in self._entity_list:
1110            ent.set_module(self)
1111
1112    def visit(self, visitor):
1113        visitor.visit_begin(self)
1114        for mod in self._module_dict.values():
1115            mod.visit(visitor)
1116        visitor.visit_end()
1117