xref: /openbmc/qemu/scripts/qapi/schema.py (revision 64547a3b)
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 check(self, schema):
197        QAPISchemaEntity.check(self, schema)
198        if 'deprecated' in [f.name for f in self.features]:
199            raise QAPISemError(
200                self.info, "feature 'deprecated' is not supported for types")
201
202    def describe(self):
203        assert self.meta
204        return "%s type '%s'" % (self.meta, self.name)
205
206
207class QAPISchemaBuiltinType(QAPISchemaType):
208    meta = 'built-in'
209
210    def __init__(self, name, json_type, c_type):
211        super().__init__(name, None, None)
212        assert not c_type or isinstance(c_type, str)
213        assert json_type in ('string', 'number', 'int', 'boolean', 'null',
214                             'value')
215        self._json_type_name = json_type
216        self._c_type_name = c_type
217
218    def c_name(self):
219        return self.name
220
221    def c_type(self):
222        return self._c_type_name
223
224    def c_param_type(self):
225        if self.name == 'str':
226            return 'const ' + self._c_type_name
227        return self._c_type_name
228
229    def json_type(self):
230        return self._json_type_name
231
232    def doc_type(self):
233        return self.json_type()
234
235    def visit(self, visitor):
236        super().visit(visitor)
237        visitor.visit_builtin_type(self.name, self.info, self.json_type())
238
239
240class QAPISchemaEnumType(QAPISchemaType):
241    meta = 'enum'
242
243    def __init__(self, name, info, doc, ifcond, features, members, prefix):
244        super().__init__(name, info, doc, ifcond, features)
245        for m in members:
246            assert isinstance(m, QAPISchemaEnumMember)
247            m.set_defined_in(name)
248        assert prefix is None or isinstance(prefix, str)
249        self.members = members
250        self.prefix = prefix
251
252    def check(self, schema):
253        super().check(schema)
254        seen = {}
255        for m in self.members:
256            m.check_clash(self.info, seen)
257
258    def connect_doc(self, doc=None):
259        super().connect_doc(doc)
260        doc = doc or self.doc
261        for m in self.members:
262            m.connect_doc(doc)
263
264    def is_implicit(self):
265        # See QAPISchema._make_implicit_enum_type() and ._def_predefineds()
266        return self.name.endswith('Kind') or self.name == 'QType'
267
268    def c_type(self):
269        return c_name(self.name)
270
271    def member_names(self):
272        return [m.name for m in self.members]
273
274    def json_type(self):
275        return 'string'
276
277    def visit(self, visitor):
278        super().visit(visitor)
279        visitor.visit_enum_type(
280            self.name, self.info, self.ifcond, self.features,
281            self.members, self.prefix)
282
283
284class QAPISchemaArrayType(QAPISchemaType):
285    meta = 'array'
286
287    def __init__(self, name, info, element_type):
288        super().__init__(name, info, None)
289        assert isinstance(element_type, str)
290        self._element_type_name = element_type
291        self.element_type = None
292
293    def check(self, schema):
294        super().check(schema)
295        self.element_type = schema.resolve_type(
296            self._element_type_name, self.info,
297            self.info and self.info.defn_meta)
298        assert not isinstance(self.element_type, QAPISchemaArrayType)
299
300    def set_module(self, schema):
301        self._set_module(schema, self.element_type.info)
302
303    @property
304    def ifcond(self):
305        assert self._checked
306        return self.element_type.ifcond
307
308    def is_implicit(self):
309        return True
310
311    def c_type(self):
312        return c_name(self.name) + pointer_suffix
313
314    def json_type(self):
315        return 'array'
316
317    def doc_type(self):
318        elt_doc_type = self.element_type.doc_type()
319        if not elt_doc_type:
320            return None
321        return 'array of ' + elt_doc_type
322
323    def visit(self, visitor):
324        super().visit(visitor)
325        visitor.visit_array_type(self.name, self.info, self.ifcond,
326                                 self.element_type)
327
328    def describe(self):
329        assert self.meta
330        return "%s type ['%s']" % (self.meta, self._element_type_name)
331
332
333class QAPISchemaObjectType(QAPISchemaType):
334    def __init__(self, name, info, doc, ifcond, features,
335                 base, local_members, variants):
336        # struct has local_members, optional base, and no variants
337        # flat union has base, variants, and no local_members
338        # simple union has local_members, variants, and no base
339        super().__init__(name, info, doc, ifcond, features)
340        self.meta = 'union' if variants else 'struct'
341        assert base is None or isinstance(base, str)
342        for m in local_members:
343            assert isinstance(m, QAPISchemaObjectTypeMember)
344            m.set_defined_in(name)
345        if variants is not None:
346            assert isinstance(variants, QAPISchemaVariants)
347            variants.set_defined_in(name)
348        self._base_name = base
349        self.base = None
350        self.local_members = local_members
351        self.variants = variants
352        self.members = None
353
354    def check(self, schema):
355        # This calls another type T's .check() exactly when the C
356        # struct emitted by gen_object() contains that T's C struct
357        # (pointers don't count).
358        if self.members is not None:
359            # A previous .check() completed: nothing to do
360            return
361        if self._checked:
362            # Recursed: C struct contains itself
363            raise QAPISemError(self.info,
364                               "object %s contains itself" % self.name)
365
366        super().check(schema)
367        assert self._checked and self.members is None
368
369        seen = OrderedDict()
370        if self._base_name:
371            self.base = schema.resolve_type(self._base_name, self.info,
372                                            "'base'")
373            if (not isinstance(self.base, QAPISchemaObjectType)
374                    or self.base.variants):
375                raise QAPISemError(
376                    self.info,
377                    "'base' requires a struct type, %s isn't"
378                    % self.base.describe())
379            self.base.check(schema)
380            self.base.check_clash(self.info, seen)
381        for m in self.local_members:
382            m.check(schema)
383            m.check_clash(self.info, seen)
384        members = seen.values()
385
386        if self.variants:
387            self.variants.check(schema, seen)
388            self.variants.check_clash(self.info, seen)
389
390        self.members = members  # mark completed
391
392    # Check that the members of this type do not cause duplicate JSON members,
393    # and update seen to track the members seen so far. Report any errors
394    # on behalf of info, which is not necessarily self.info
395    def check_clash(self, info, seen):
396        assert self._checked
397        assert not self.variants       # not implemented
398        for m in self.members:
399            m.check_clash(info, seen)
400
401    def connect_doc(self, doc=None):
402        super().connect_doc(doc)
403        doc = doc or self.doc
404        if self.base and self.base.is_implicit():
405            self.base.connect_doc(doc)
406        for m in self.local_members:
407            m.connect_doc(doc)
408
409    @property
410    def ifcond(self):
411        assert self._checked
412        if isinstance(self._ifcond, QAPISchemaType):
413            # Simple union wrapper type inherits from wrapped type;
414            # see _make_implicit_object_type()
415            return self._ifcond.ifcond
416        return self._ifcond
417
418    def is_implicit(self):
419        # See QAPISchema._make_implicit_object_type(), as well as
420        # _def_predefineds()
421        return self.name.startswith('q_')
422
423    def is_empty(self):
424        assert self.members is not None
425        return not self.members and not self.variants
426
427    def c_name(self):
428        assert self.name != 'q_empty'
429        return super().c_name()
430
431    def c_type(self):
432        assert not self.is_implicit()
433        return c_name(self.name) + pointer_suffix
434
435    def c_unboxed_type(self):
436        return c_name(self.name)
437
438    def json_type(self):
439        return 'object'
440
441    def visit(self, visitor):
442        super().visit(visitor)
443        visitor.visit_object_type(
444            self.name, self.info, self.ifcond, self.features,
445            self.base, self.local_members, self.variants)
446        visitor.visit_object_type_flat(
447            self.name, self.info, self.ifcond, self.features,
448            self.members, self.variants)
449
450
451class QAPISchemaAlternateType(QAPISchemaType):
452    meta = 'alternate'
453
454    def __init__(self, name, info, doc, ifcond, features, variants):
455        super().__init__(name, info, doc, ifcond, features)
456        assert isinstance(variants, QAPISchemaVariants)
457        assert variants.tag_member
458        variants.set_defined_in(name)
459        variants.tag_member.set_defined_in(self.name)
460        self.variants = variants
461
462    def check(self, schema):
463        super().check(schema)
464        self.variants.tag_member.check(schema)
465        # Not calling self.variants.check_clash(), because there's nothing
466        # to clash with
467        self.variants.check(schema, {})
468        # Alternate branch names have no relation to the tag enum values;
469        # so we have to check for potential name collisions ourselves.
470        seen = {}
471        types_seen = {}
472        for v in self.variants.variants:
473            v.check_clash(self.info, seen)
474            qtype = v.type.alternate_qtype()
475            if not qtype:
476                raise QAPISemError(
477                    self.info,
478                    "%s cannot use %s"
479                    % (v.describe(self.info), v.type.describe()))
480            conflicting = set([qtype])
481            if qtype == 'QTYPE_QSTRING':
482                if isinstance(v.type, QAPISchemaEnumType):
483                    for m in v.type.members:
484                        if m.name in ['on', 'off']:
485                            conflicting.add('QTYPE_QBOOL')
486                        if re.match(r'[-+0-9.]', m.name):
487                            # lazy, could be tightened
488                            conflicting.add('QTYPE_QNUM')
489                else:
490                    conflicting.add('QTYPE_QNUM')
491                    conflicting.add('QTYPE_QBOOL')
492            for qt in conflicting:
493                if qt in types_seen:
494                    raise QAPISemError(
495                        self.info,
496                        "%s can't be distinguished from '%s'"
497                        % (v.describe(self.info), types_seen[qt]))
498                types_seen[qt] = v.name
499
500    def connect_doc(self, doc=None):
501        super().connect_doc(doc)
502        doc = doc or self.doc
503        for v in self.variants.variants:
504            v.connect_doc(doc)
505
506    def c_type(self):
507        return c_name(self.name) + pointer_suffix
508
509    def json_type(self):
510        return 'value'
511
512    def visit(self, visitor):
513        super().visit(visitor)
514        visitor.visit_alternate_type(
515            self.name, self.info, self.ifcond, self.features, self.variants)
516
517
518class QAPISchemaVariants:
519    def __init__(self, tag_name, info, tag_member, variants):
520        # Flat unions pass tag_name but not tag_member.
521        # Simple unions and alternates pass tag_member but not tag_name.
522        # After check(), tag_member is always set, and tag_name remains
523        # a reliable witness of being used by a flat union.
524        assert bool(tag_member) != bool(tag_name)
525        assert (isinstance(tag_name, str) or
526                isinstance(tag_member, QAPISchemaObjectTypeMember))
527        for v in variants:
528            assert isinstance(v, QAPISchemaVariant)
529        self._tag_name = tag_name
530        self.info = info
531        self.tag_member = tag_member
532        self.variants = variants
533
534    def set_defined_in(self, name):
535        for v in self.variants:
536            v.set_defined_in(name)
537
538    def check(self, schema, seen):
539        if not self.tag_member: # flat union
540            self.tag_member = seen.get(c_name(self._tag_name))
541            base = "'base'"
542            # Pointing to the base type when not implicit would be
543            # nice, but we don't know it here
544            if not self.tag_member or self._tag_name != self.tag_member.name:
545                raise QAPISemError(
546                    self.info,
547                    "discriminator '%s' is not a member of %s"
548                    % (self._tag_name, base))
549            # Here we do:
550            base_type = schema.lookup_type(self.tag_member.defined_in)
551            assert base_type
552            if not base_type.is_implicit():
553                base = "base type '%s'" % self.tag_member.defined_in
554            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
555                raise QAPISemError(
556                    self.info,
557                    "discriminator member '%s' of %s must be of enum type"
558                    % (self._tag_name, base))
559            if self.tag_member.optional:
560                raise QAPISemError(
561                    self.info,
562                    "discriminator member '%s' of %s must not be optional"
563                    % (self._tag_name, base))
564            if self.tag_member.ifcond:
565                raise QAPISemError(
566                    self.info,
567                    "discriminator member '%s' of %s must not be conditional"
568                    % (self._tag_name, base))
569        else:                   # simple union
570            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
571            assert not self.tag_member.optional
572            assert self.tag_member.ifcond == []
573        if self._tag_name:    # flat union
574            # branches that are not explicitly covered get an empty type
575            cases = {v.name for v in self.variants}
576            for m in self.tag_member.type.members:
577                if m.name not in cases:
578                    v = QAPISchemaVariant(m.name, self.info,
579                                          'q_empty', m.ifcond)
580                    v.set_defined_in(self.tag_member.defined_in)
581                    self.variants.append(v)
582        if not self.variants:
583            raise QAPISemError(self.info, "union has no branches")
584        for v in self.variants:
585            v.check(schema)
586            # Union names must match enum values; alternate names are
587            # checked separately. Use 'seen' to tell the two apart.
588            if seen:
589                if v.name not in self.tag_member.type.member_names():
590                    raise QAPISemError(
591                        self.info,
592                        "branch '%s' is not a value of %s"
593                        % (v.name, self.tag_member.type.describe()))
594                if (not isinstance(v.type, QAPISchemaObjectType)
595                        or v.type.variants):
596                    raise QAPISemError(
597                        self.info,
598                        "%s cannot use %s"
599                        % (v.describe(self.info), v.type.describe()))
600                v.type.check(schema)
601
602    def check_clash(self, info, seen):
603        for v in self.variants:
604            # Reset seen map for each variant, since qapi names from one
605            # branch do not affect another branch
606            v.type.check_clash(info, dict(seen))
607
608
609class QAPISchemaMember:
610    """ Represents object members, enum members and features """
611    role = 'member'
612
613    def __init__(self, name, info, ifcond=None):
614        assert isinstance(name, str)
615        self.name = name
616        self.info = info
617        self.ifcond = ifcond or []
618        self.defined_in = None
619
620    def set_defined_in(self, name):
621        assert not self.defined_in
622        self.defined_in = name
623
624    def check_clash(self, info, seen):
625        cname = c_name(self.name)
626        if cname in seen:
627            raise QAPISemError(
628                info,
629                "%s collides with %s"
630                % (self.describe(info), seen[cname].describe(info)))
631        seen[cname] = self
632
633    def connect_doc(self, doc):
634        if doc:
635            doc.connect_member(self)
636
637    def describe(self, info):
638        role = self.role
639        defined_in = self.defined_in
640        assert defined_in
641
642        if defined_in.startswith('q_obj_'):
643            # See QAPISchema._make_implicit_object_type() - reverse the
644            # mapping there to create a nice human-readable description
645            defined_in = defined_in[6:]
646            if defined_in.endswith('-arg'):
647                # Implicit type created for a command's dict 'data'
648                assert role == 'member'
649                role = 'parameter'
650            elif defined_in.endswith('-base'):
651                # Implicit type created for a flat union's dict 'base'
652                role = 'base ' + role
653            else:
654                # Implicit type created for a simple union's branch
655                assert defined_in.endswith('-wrapper')
656                # Unreachable and not implemented
657                assert False
658        elif defined_in.endswith('Kind'):
659            # See QAPISchema._make_implicit_enum_type()
660            # Implicit enum created for simple union's branches
661            assert role == 'value'
662            role = 'branch'
663        elif defined_in != info.defn_name:
664            return "%s '%s' of type '%s'" % (role, self.name, defined_in)
665        return "%s '%s'" % (role, self.name)
666
667
668class QAPISchemaEnumMember(QAPISchemaMember):
669    role = 'value'
670
671
672class QAPISchemaFeature(QAPISchemaMember):
673    role = 'feature'
674
675
676class QAPISchemaObjectTypeMember(QAPISchemaMember):
677    def __init__(self, name, info, typ, optional, ifcond=None, features=None):
678        super().__init__(name, info, ifcond)
679        assert isinstance(typ, str)
680        assert isinstance(optional, bool)
681        for f in features or []:
682            assert isinstance(f, QAPISchemaFeature)
683            f.set_defined_in(name)
684        self._type_name = typ
685        self.type = None
686        self.optional = optional
687        self.features = features or []
688
689    def check(self, schema):
690        assert self.defined_in
691        self.type = schema.resolve_type(self._type_name, self.info,
692                                        self.describe)
693        seen = {}
694        for f in self.features:
695            f.check_clash(self.info, seen)
696
697    def connect_doc(self, doc):
698        super().connect_doc(doc)
699        if doc:
700            for f in self.features:
701                doc.connect_feature(f)
702
703
704class QAPISchemaVariant(QAPISchemaObjectTypeMember):
705    role = 'branch'
706
707    def __init__(self, name, info, typ, ifcond=None):
708        super().__init__(name, info, typ, False, ifcond)
709
710
711class QAPISchemaCommand(QAPISchemaEntity):
712    meta = 'command'
713
714    def __init__(self, name, info, doc, ifcond, features,
715                 arg_type, ret_type,
716                 gen, success_response, boxed, allow_oob, allow_preconfig):
717        super().__init__(name, info, doc, ifcond, features)
718        assert not arg_type or isinstance(arg_type, str)
719        assert not ret_type or isinstance(ret_type, str)
720        self._arg_type_name = arg_type
721        self.arg_type = None
722        self._ret_type_name = ret_type
723        self.ret_type = None
724        self.gen = gen
725        self.success_response = success_response
726        self.boxed = boxed
727        self.allow_oob = allow_oob
728        self.allow_preconfig = allow_preconfig
729
730    def check(self, schema):
731        super().check(schema)
732        if self._arg_type_name:
733            self.arg_type = schema.resolve_type(
734                self._arg_type_name, self.info, "command's 'data'")
735            if not isinstance(self.arg_type, QAPISchemaObjectType):
736                raise QAPISemError(
737                    self.info,
738                    "command's 'data' cannot take %s"
739                    % self.arg_type.describe())
740            if self.arg_type.variants and not self.boxed:
741                raise QAPISemError(
742                    self.info,
743                    "command's 'data' can take %s only with 'boxed': true"
744                    % self.arg_type.describe())
745        if self._ret_type_name:
746            self.ret_type = schema.resolve_type(
747                self._ret_type_name, self.info, "command's 'returns'")
748            if self.name not in self.info.pragma.returns_whitelist:
749                typ = self.ret_type
750                if isinstance(typ, QAPISchemaArrayType):
751                    typ = self.ret_type.element_type
752                    assert typ
753                if not isinstance(typ, QAPISchemaObjectType):
754                    raise QAPISemError(
755                        self.info,
756                        "command's 'returns' cannot take %s"
757                        % self.ret_type.describe())
758
759    def connect_doc(self, doc=None):
760        super().connect_doc(doc)
761        doc = doc or self.doc
762        if doc:
763            if self.arg_type and self.arg_type.is_implicit():
764                self.arg_type.connect_doc(doc)
765
766    def visit(self, visitor):
767        super().visit(visitor)
768        visitor.visit_command(
769            self.name, self.info, self.ifcond, self.features,
770            self.arg_type, self.ret_type, self.gen, self.success_response,
771            self.boxed, self.allow_oob, self.allow_preconfig)
772
773
774class QAPISchemaEvent(QAPISchemaEntity):
775    meta = 'event'
776
777    def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
778        super().__init__(name, info, doc, ifcond, features)
779        assert not arg_type or isinstance(arg_type, str)
780        self._arg_type_name = arg_type
781        self.arg_type = None
782        self.boxed = boxed
783
784    def check(self, schema):
785        super().check(schema)
786        if self._arg_type_name:
787            self.arg_type = schema.resolve_type(
788                self._arg_type_name, self.info, "event's 'data'")
789            if not isinstance(self.arg_type, QAPISchemaObjectType):
790                raise QAPISemError(
791                    self.info,
792                    "event's 'data' cannot take %s"
793                    % self.arg_type.describe())
794            if self.arg_type.variants and not self.boxed:
795                raise QAPISemError(
796                    self.info,
797                    "event's 'data' can take %s only with 'boxed': true"
798                    % self.arg_type.describe())
799
800    def connect_doc(self, doc=None):
801        super().connect_doc(doc)
802        doc = doc or self.doc
803        if doc:
804            if self.arg_type and self.arg_type.is_implicit():
805                self.arg_type.connect_doc(doc)
806
807    def visit(self, visitor):
808        super().visit(visitor)
809        visitor.visit_event(
810            self.name, self.info, self.ifcond, self.features,
811            self.arg_type, self.boxed)
812
813
814class QAPISchema:
815    def __init__(self, fname):
816        self.fname = fname
817        parser = QAPISchemaParser(fname)
818        exprs = check_exprs(parser.exprs)
819        self.docs = parser.docs
820        self._entity_list = []
821        self._entity_dict = {}
822        self._module_dict = OrderedDict()
823        self._schema_dir = os.path.dirname(fname)
824        self._make_module(None) # built-ins
825        self._make_module(fname)
826        self._predefining = True
827        self._def_predefineds()
828        self._predefining = False
829        self._def_exprs(exprs)
830        self.check()
831
832    def _def_entity(self, ent):
833        # Only the predefined types are allowed to not have info
834        assert ent.info or self._predefining
835        self._entity_list.append(ent)
836        if ent.name is None:
837            return
838        # TODO reject names that differ only in '_' vs. '.'  vs. '-',
839        # because they're liable to clash in generated C.
840        other_ent = self._entity_dict.get(ent.name)
841        if other_ent:
842            if other_ent.info:
843                where = QAPIError(other_ent.info, None, "previous definition")
844                raise QAPISemError(
845                    ent.info,
846                    "'%s' is already defined\n%s" % (ent.name, where))
847            raise QAPISemError(
848                ent.info, "%s is already defined" % other_ent.describe())
849        self._entity_dict[ent.name] = ent
850
851    def lookup_entity(self, name, typ=None):
852        ent = self._entity_dict.get(name)
853        if typ and not isinstance(ent, typ):
854            return None
855        return ent
856
857    def lookup_type(self, name):
858        return self.lookup_entity(name, QAPISchemaType)
859
860    def resolve_type(self, name, info, what):
861        typ = self.lookup_type(name)
862        if not typ:
863            if callable(what):
864                what = what(info)
865            raise QAPISemError(
866                info, "%s uses unknown type '%s'" % (what, name))
867        return typ
868
869    def _module_name(self, fname):
870        if fname is None:
871            return None
872        return os.path.relpath(fname, self._schema_dir)
873
874    def _make_module(self, fname):
875        name = self._module_name(fname)
876        if name not in self._module_dict:
877            self._module_dict[name] = QAPISchemaModule(name)
878        return self._module_dict[name]
879
880    def module_by_fname(self, fname):
881        name = self._module_name(fname)
882        assert name in self._module_dict
883        return self._module_dict[name]
884
885    def _def_include(self, expr, info, doc):
886        include = expr['include']
887        assert doc is None
888        self._def_entity(QAPISchemaInclude(self._make_module(include), info))
889
890    def _def_builtin_type(self, name, json_type, c_type):
891        self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
892        # Instantiating only the arrays that are actually used would
893        # be nice, but we can't as long as their generated code
894        # (qapi-builtin-types.[ch]) may be shared by some other
895        # schema.
896        self._make_array_type(name, None)
897
898    def _def_predefineds(self):
899        for t in [('str',    'string',  'char' + pointer_suffix),
900                  ('number', 'number',  'double'),
901                  ('int',    'int',     'int64_t'),
902                  ('int8',   'int',     'int8_t'),
903                  ('int16',  'int',     'int16_t'),
904                  ('int32',  'int',     'int32_t'),
905                  ('int64',  'int',     'int64_t'),
906                  ('uint8',  'int',     'uint8_t'),
907                  ('uint16', 'int',     'uint16_t'),
908                  ('uint32', 'int',     'uint32_t'),
909                  ('uint64', 'int',     'uint64_t'),
910                  ('size',   'int',     'uint64_t'),
911                  ('bool',   'boolean', 'bool'),
912                  ('any',    'value',   'QObject' + pointer_suffix),
913                  ('null',   'null',    'QNull' + pointer_suffix)]:
914            self._def_builtin_type(*t)
915        self.the_empty_object_type = QAPISchemaObjectType(
916            'q_empty', None, None, None, None, None, [], None)
917        self._def_entity(self.the_empty_object_type)
918
919        qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
920                  'qbool']
921        qtype_values = self._make_enum_members(
922            [{'name': n} for n in qtypes], None)
923
924        self._def_entity(QAPISchemaEnumType('QType', None, None, None, None,
925                                            qtype_values, 'QTYPE'))
926
927    def _make_features(self, features, info):
928        if features is None:
929            return []
930        return [QAPISchemaFeature(f['name'], info, f.get('if'))
931                for f in features]
932
933    def _make_enum_members(self, values, info):
934        return [QAPISchemaEnumMember(v['name'], info, v.get('if'))
935                for v in values]
936
937    def _make_implicit_enum_type(self, name, info, ifcond, values):
938        # See also QAPISchemaObjectTypeMember.describe()
939        name = name + 'Kind'    # reserved by check_defn_name_str()
940        self._def_entity(QAPISchemaEnumType(
941            name, info, None, ifcond, None,
942            self._make_enum_members(values, info),
943            None))
944        return name
945
946    def _make_array_type(self, element_type, info):
947        name = element_type + 'List'    # reserved by check_defn_name_str()
948        if not self.lookup_type(name):
949            self._def_entity(QAPISchemaArrayType(name, info, element_type))
950        return name
951
952    def _make_implicit_object_type(self, name, info, ifcond, role, members):
953        if not members:
954            return None
955        # See also QAPISchemaObjectTypeMember.describe()
956        name = 'q_obj_%s-%s' % (name, role)
957        typ = self.lookup_entity(name, QAPISchemaObjectType)
958        if typ:
959            # The implicit object type has multiple users.  This can
960            # happen only for simple unions' implicit wrapper types.
961            # Its ifcond should be the disjunction of its user's
962            # ifconds.  Not implemented.  Instead, we always pass the
963            # wrapped type's ifcond, which is trivially the same for all
964            # users.  It's also necessary for the wrapper to compile.
965            # But it's not tight: the disjunction need not imply it.  We
966            # may end up compiling useless wrapper types.
967            # TODO kill simple unions or implement the disjunction
968            assert (ifcond or []) == typ._ifcond # pylint: disable=protected-access
969        else:
970            self._def_entity(QAPISchemaObjectType(
971                name, info, None, ifcond, None, None, members, None))
972        return name
973
974    def _def_enum_type(self, expr, info, doc):
975        name = expr['enum']
976        data = expr['data']
977        prefix = expr.get('prefix')
978        ifcond = expr.get('if')
979        features = self._make_features(expr.get('features'), info)
980        self._def_entity(QAPISchemaEnumType(
981            name, info, doc, ifcond, features,
982            self._make_enum_members(data, info), prefix))
983
984    def _make_member(self, name, typ, ifcond, features, info):
985        optional = False
986        if name.startswith('*'):
987            name = name[1:]
988            optional = True
989        if isinstance(typ, list):
990            assert len(typ) == 1
991            typ = self._make_array_type(typ[0], info)
992        return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond,
993                                          self._make_features(features, info))
994
995    def _make_members(self, data, info):
996        return [self._make_member(key, value['type'], value.get('if'),
997                                  value.get('features'), info)
998                for (key, value) in data.items()]
999
1000    def _def_struct_type(self, expr, info, doc):
1001        name = expr['struct']
1002        base = expr.get('base')
1003        data = expr['data']
1004        ifcond = expr.get('if')
1005        features = self._make_features(expr.get('features'), info)
1006        self._def_entity(QAPISchemaObjectType(
1007            name, info, doc, ifcond, features, base,
1008            self._make_members(data, info),
1009            None))
1010
1011    def _make_variant(self, case, typ, ifcond, info):
1012        return QAPISchemaVariant(case, info, typ, ifcond)
1013
1014    def _make_simple_variant(self, case, typ, ifcond, info):
1015        if isinstance(typ, list):
1016            assert len(typ) == 1
1017            typ = self._make_array_type(typ[0], info)
1018        typ = self._make_implicit_object_type(
1019            typ, info, self.lookup_type(typ),
1020            'wrapper', [self._make_member('data', typ, None, None, info)])
1021        return QAPISchemaVariant(case, info, typ, ifcond)
1022
1023    def _def_union_type(self, expr, info, doc):
1024        name = expr['union']
1025        data = expr['data']
1026        base = expr.get('base')
1027        ifcond = expr.get('if')
1028        features = self._make_features(expr.get('features'), info)
1029        tag_name = expr.get('discriminator')
1030        tag_member = None
1031        if isinstance(base, dict):
1032            base = self._make_implicit_object_type(
1033                name, info, ifcond,
1034                'base', self._make_members(base, info))
1035        if tag_name:
1036            variants = [self._make_variant(key, value['type'],
1037                                           value.get('if'), info)
1038                        for (key, value) in data.items()]
1039            members = []
1040        else:
1041            variants = [self._make_simple_variant(key, value['type'],
1042                                                  value.get('if'), info)
1043                        for (key, value) in data.items()]
1044            enum = [{'name': v.name, 'if': v.ifcond} for v in variants]
1045            typ = self._make_implicit_enum_type(name, info, ifcond, enum)
1046            tag_member = QAPISchemaObjectTypeMember('type', info, typ, False)
1047            members = [tag_member]
1048        self._def_entity(
1049            QAPISchemaObjectType(name, info, doc, ifcond, features,
1050                                 base, members,
1051                                 QAPISchemaVariants(
1052                                     tag_name, info, tag_member, variants)))
1053
1054    def _def_alternate_type(self, expr, info, doc):
1055        name = expr['alternate']
1056        data = expr['data']
1057        ifcond = expr.get('if')
1058        features = self._make_features(expr.get('features'), info)
1059        variants = [self._make_variant(key, value['type'], value.get('if'),
1060                                       info)
1061                    for (key, value) in data.items()]
1062        tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1063        self._def_entity(
1064            QAPISchemaAlternateType(name, info, doc, ifcond, features,
1065                                    QAPISchemaVariants(
1066                                        None, info, tag_member, variants)))
1067
1068    def _def_command(self, expr, info, doc):
1069        name = expr['command']
1070        data = expr.get('data')
1071        rets = expr.get('returns')
1072        gen = expr.get('gen', True)
1073        success_response = expr.get('success-response', True)
1074        boxed = expr.get('boxed', False)
1075        allow_oob = expr.get('allow-oob', False)
1076        allow_preconfig = expr.get('allow-preconfig', False)
1077        ifcond = expr.get('if')
1078        features = self._make_features(expr.get('features'), info)
1079        if isinstance(data, OrderedDict):
1080            data = self._make_implicit_object_type(
1081                name, info, ifcond,
1082                'arg', self._make_members(data, info))
1083        if isinstance(rets, list):
1084            assert len(rets) == 1
1085            rets = self._make_array_type(rets[0], info)
1086        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, features,
1087                                           data, rets,
1088                                           gen, success_response,
1089                                           boxed, allow_oob, allow_preconfig))
1090
1091    def _def_event(self, expr, info, doc):
1092        name = expr['event']
1093        data = expr.get('data')
1094        boxed = expr.get('boxed', False)
1095        ifcond = expr.get('if')
1096        features = self._make_features(expr.get('features'), info)
1097        if isinstance(data, OrderedDict):
1098            data = self._make_implicit_object_type(
1099                name, info, ifcond,
1100                'arg', self._make_members(data, info))
1101        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, features,
1102                                         data, boxed))
1103
1104    def _def_exprs(self, exprs):
1105        for expr_elem in exprs:
1106            expr = expr_elem['expr']
1107            info = expr_elem['info']
1108            doc = expr_elem.get('doc')
1109            if 'enum' in expr:
1110                self._def_enum_type(expr, info, doc)
1111            elif 'struct' in expr:
1112                self._def_struct_type(expr, info, doc)
1113            elif 'union' in expr:
1114                self._def_union_type(expr, info, doc)
1115            elif 'alternate' in expr:
1116                self._def_alternate_type(expr, info, doc)
1117            elif 'command' in expr:
1118                self._def_command(expr, info, doc)
1119            elif 'event' in expr:
1120                self._def_event(expr, info, doc)
1121            elif 'include' in expr:
1122                self._def_include(expr, info, doc)
1123            else:
1124                assert False
1125
1126    def check(self):
1127        for ent in self._entity_list:
1128            ent.check(self)
1129            ent.connect_doc()
1130            ent.check_doc()
1131        for ent in self._entity_list:
1132            ent.set_module(self)
1133
1134    def visit(self, visitor):
1135        visitor.visit_begin(self)
1136        for mod in self._module_dict.values():
1137            mod.visit(visitor)
1138        visitor.visit_end()
1139