xref: /openbmc/qemu/scripts/qapi/schema.py (revision 1192a4862b02b01c77415c3c04b5931e2b0b42bf)
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, QAPIParseError, QAPISemError
23from qapi.expr import check_exprs
24from qapi.parser import QAPISchemaParser
25
26
27class QAPISchemaEntity(object):
28    meta = None
29
30    def __init__(self, name, info, doc, ifcond=None):
31        assert name is None or isinstance(name, str)
32        self.name = name
33        self._module = None
34        # For explicitly defined entities, info points to the (explicit)
35        # definition.  For builtins (and their arrays), info is None.
36        # For implicitly defined entities, info points to a place that
37        # triggered the implicit definition (there may be more than one
38        # such place).
39        self.info = info
40        self.doc = doc
41        self._ifcond = ifcond or []
42        self._checked = False
43
44    def c_name(self):
45        return c_name(self.name)
46
47    def check(self, schema):
48        assert not self._checked
49        if self.info:
50            self._module = os.path.relpath(self.info.fname,
51                                           os.path.dirname(schema.fname))
52        self._checked = True
53
54    def connect_doc(self, doc=None):
55        pass
56
57    def check_doc(self):
58        if self.doc:
59            self.doc.check()
60
61    @property
62    def ifcond(self):
63        assert self._checked
64        return self._ifcond
65
66    @property
67    def module(self):
68        assert self._checked
69        return self._module
70
71    def is_implicit(self):
72        return not self.info
73
74    def visit(self, visitor):
75        assert self._checked
76
77    def describe(self):
78        assert self.meta
79        return "%s '%s'" % (self.meta, self.name)
80
81
82class QAPISchemaVisitor(object):
83    def visit_begin(self, schema):
84        pass
85
86    def visit_end(self):
87        pass
88
89    def visit_module(self, fname):
90        pass
91
92    def visit_needed(self, entity):
93        # Default to visiting everything
94        return True
95
96    def visit_include(self, fname, info):
97        pass
98
99    def visit_builtin_type(self, name, info, json_type):
100        pass
101
102    def visit_enum_type(self, name, info, ifcond, members, prefix):
103        pass
104
105    def visit_array_type(self, name, info, ifcond, element_type):
106        pass
107
108    def visit_object_type(self, name, info, ifcond, base, members, variants,
109                          features):
110        pass
111
112    def visit_object_type_flat(self, name, info, ifcond, members, variants,
113                               features):
114        pass
115
116    def visit_alternate_type(self, name, info, ifcond, variants):
117        pass
118
119    def visit_command(self, name, info, ifcond, arg_type, ret_type, gen,
120                      success_response, boxed, allow_oob, allow_preconfig,
121                      features):
122        pass
123
124    def visit_event(self, name, info, ifcond, arg_type, boxed):
125        pass
126
127
128class QAPISchemaInclude(QAPISchemaEntity):
129
130    def __init__(self, fname, info):
131        QAPISchemaEntity.__init__(self, None, info, None)
132        self.fname = fname
133
134    def visit(self, visitor):
135        QAPISchemaEntity.visit(self, visitor)
136        visitor.visit_include(self.fname, self.info)
137
138
139class QAPISchemaType(QAPISchemaEntity):
140    # Return the C type for common use.
141    # For the types we commonly box, this is a pointer type.
142    def c_type(self):
143        pass
144
145    # Return the C type to be used in a parameter list.
146    def c_param_type(self):
147        return self.c_type()
148
149    # Return the C type to be used where we suppress boxing.
150    def c_unboxed_type(self):
151        return self.c_type()
152
153    def json_type(self):
154        pass
155
156    def alternate_qtype(self):
157        json2qtype = {
158            'null':    'QTYPE_QNULL',
159            'string':  'QTYPE_QSTRING',
160            'number':  'QTYPE_QNUM',
161            'int':     'QTYPE_QNUM',
162            'boolean': 'QTYPE_QBOOL',
163            'object':  'QTYPE_QDICT'
164        }
165        return json2qtype.get(self.json_type())
166
167    def doc_type(self):
168        if self.is_implicit():
169            return None
170        return self.name
171
172    def describe(self):
173        assert self.meta
174        return "%s type '%s'" % (self.meta, self.name)
175
176
177class QAPISchemaBuiltinType(QAPISchemaType):
178    meta = 'built-in'
179
180    def __init__(self, name, json_type, c_type):
181        QAPISchemaType.__init__(self, name, None, None)
182        assert not c_type or isinstance(c_type, str)
183        assert json_type in ('string', 'number', 'int', 'boolean', 'null',
184                             'value')
185        self._json_type_name = json_type
186        self._c_type_name = c_type
187
188    def c_name(self):
189        return self.name
190
191    def c_type(self):
192        return self._c_type_name
193
194    def c_param_type(self):
195        if self.name == 'str':
196            return 'const ' + self._c_type_name
197        return self._c_type_name
198
199    def json_type(self):
200        return self._json_type_name
201
202    def doc_type(self):
203        return self.json_type()
204
205    def visit(self, visitor):
206        QAPISchemaType.visit(self, visitor)
207        visitor.visit_builtin_type(self.name, self.info, self.json_type())
208
209
210class QAPISchemaEnumType(QAPISchemaType):
211    meta = 'enum'
212
213    def __init__(self, name, info, doc, ifcond, members, prefix):
214        QAPISchemaType.__init__(self, name, info, doc, ifcond)
215        for m in members:
216            assert isinstance(m, QAPISchemaEnumMember)
217            m.set_defined_in(name)
218        assert prefix is None or isinstance(prefix, str)
219        self.members = members
220        self.prefix = prefix
221
222    def check(self, schema):
223        QAPISchemaType.check(self, schema)
224        seen = {}
225        for m in self.members:
226            m.check_clash(self.info, seen)
227
228    def connect_doc(self, doc=None):
229        doc = doc or self.doc
230        if doc:
231            for m in self.members:
232                doc.connect_member(m)
233
234    def is_implicit(self):
235        # See QAPISchema._make_implicit_enum_type() and ._def_predefineds()
236        return self.name.endswith('Kind') or self.name == 'QType'
237
238    def c_type(self):
239        return c_name(self.name)
240
241    def member_names(self):
242        return [m.name for m in self.members]
243
244    def json_type(self):
245        return 'string'
246
247    def visit(self, visitor):
248        QAPISchemaType.visit(self, visitor)
249        visitor.visit_enum_type(self.name, self.info, self.ifcond,
250                                self.members, self.prefix)
251
252
253class QAPISchemaArrayType(QAPISchemaType):
254    meta = 'array'
255
256    def __init__(self, name, info, element_type):
257        QAPISchemaType.__init__(self, name, info, None, None)
258        assert isinstance(element_type, str)
259        self._element_type_name = element_type
260        self.element_type = None
261
262    def check(self, schema):
263        QAPISchemaType.check(self, schema)
264        self.element_type = schema.resolve_type(
265            self._element_type_name, self.info,
266            self.info and self.info.defn_meta)
267        assert not isinstance(self.element_type, QAPISchemaArrayType)
268
269    @property
270    def ifcond(self):
271        assert self._checked
272        return self.element_type.ifcond
273
274    @property
275    def module(self):
276        assert self._checked
277        return self.element_type.module
278
279    def is_implicit(self):
280        return True
281
282    def c_type(self):
283        return c_name(self.name) + pointer_suffix
284
285    def json_type(self):
286        return 'array'
287
288    def doc_type(self):
289        elt_doc_type = self.element_type.doc_type()
290        if not elt_doc_type:
291            return None
292        return 'array of ' + elt_doc_type
293
294    def visit(self, visitor):
295        QAPISchemaType.visit(self, visitor)
296        visitor.visit_array_type(self.name, self.info, self.ifcond,
297                                 self.element_type)
298
299    def describe(self):
300        assert self.meta
301        return "%s type ['%s']" % (self.meta, self._element_type_name)
302
303
304class QAPISchemaObjectType(QAPISchemaType):
305    def __init__(self, name, info, doc, ifcond,
306                 base, local_members, variants, features):
307        # struct has local_members, optional base, and no variants
308        # flat union has base, variants, and no local_members
309        # simple union has local_members, variants, and no base
310        QAPISchemaType.__init__(self, name, info, doc, ifcond)
311        self.meta = 'union' if variants else 'struct'
312        assert base is None or isinstance(base, str)
313        for m in local_members:
314            assert isinstance(m, QAPISchemaObjectTypeMember)
315            m.set_defined_in(name)
316        if variants is not None:
317            assert isinstance(variants, QAPISchemaObjectTypeVariants)
318            variants.set_defined_in(name)
319        for f in features:
320            assert isinstance(f, QAPISchemaFeature)
321            f.set_defined_in(name)
322        self._base_name = base
323        self.base = None
324        self.local_members = local_members
325        self.variants = variants
326        self.members = None
327        self.features = features
328
329    def check(self, schema):
330        # This calls another type T's .check() exactly when the C
331        # struct emitted by gen_object() contains that T's C struct
332        # (pointers don't count).
333        if self.members is not None:
334            # A previous .check() completed: nothing to do
335            return
336        if self._checked:
337            # Recursed: C struct contains itself
338            raise QAPISemError(self.info,
339                               "object %s contains itself" % self.name)
340
341        QAPISchemaType.check(self, schema)
342        assert self._checked and self.members is None
343
344        seen = OrderedDict()
345        if self._base_name:
346            self.base = schema.resolve_type(self._base_name, self.info,
347                                            "'base'")
348            if (not isinstance(self.base, QAPISchemaObjectType)
349                    or self.base.variants):
350                raise QAPISemError(
351                    self.info,
352                    "'base' requires a struct type, %s isn't"
353                    % self.base.describe())
354            self.base.check(schema)
355            self.base.check_clash(self.info, seen)
356        for m in self.local_members:
357            m.check(schema)
358            m.check_clash(self.info, seen)
359        members = seen.values()
360
361        if self.variants:
362            self.variants.check(schema, seen)
363            self.variants.check_clash(self.info, seen)
364
365        # Features are in a name space separate from members
366        seen = {}
367        for f in self.features:
368            f.check_clash(self.info, seen)
369
370        self.members = members  # mark completed
371
372    # Check that the members of this type do not cause duplicate JSON members,
373    # and update seen to track the members seen so far. Report any errors
374    # on behalf of info, which is not necessarily self.info
375    def check_clash(self, info, seen):
376        assert self._checked
377        assert not self.variants       # not implemented
378        for m in self.members:
379            m.check_clash(info, seen)
380
381    def connect_doc(self, doc=None):
382        doc = doc or self.doc
383        if doc:
384            if self.base and self.base.is_implicit():
385                self.base.connect_doc(doc)
386            for m in self.local_members:
387                doc.connect_member(m)
388
389    @property
390    def ifcond(self):
391        assert self._checked
392        if isinstance(self._ifcond, QAPISchemaType):
393            # Simple union wrapper type inherits from wrapped type;
394            # see _make_implicit_object_type()
395            return self._ifcond.ifcond
396        return self._ifcond
397
398    def is_implicit(self):
399        # See QAPISchema._make_implicit_object_type(), as well as
400        # _def_predefineds()
401        return self.name.startswith('q_')
402
403    def is_empty(self):
404        assert self.members is not None
405        return not self.members and not self.variants
406
407    def c_name(self):
408        assert self.name != 'q_empty'
409        return QAPISchemaType.c_name(self)
410
411    def c_type(self):
412        assert not self.is_implicit()
413        return c_name(self.name) + pointer_suffix
414
415    def c_unboxed_type(self):
416        return c_name(self.name)
417
418    def json_type(self):
419        return 'object'
420
421    def visit(self, visitor):
422        QAPISchemaType.visit(self, visitor)
423        visitor.visit_object_type(self.name, self.info, self.ifcond,
424                                  self.base, self.local_members, self.variants,
425                                  self.features)
426        visitor.visit_object_type_flat(self.name, self.info, self.ifcond,
427                                       self.members, self.variants,
428                                       self.features)
429
430
431class QAPISchemaMember(object):
432    """ Represents object members, enum members and features """
433    role = 'member'
434
435    def __init__(self, name, info, ifcond=None):
436        assert isinstance(name, str)
437        self.name = name
438        self.info = info
439        self.ifcond = ifcond or []
440        self.defined_in = None
441
442    def set_defined_in(self, name):
443        assert not self.defined_in
444        self.defined_in = name
445
446    def check_clash(self, info, seen):
447        cname = c_name(self.name)
448        if cname in seen:
449            raise QAPISemError(
450                info,
451                "%s collides with %s"
452                % (self.describe(info), seen[cname].describe(info)))
453        seen[cname] = self
454
455    def describe(self, info):
456        role = self.role
457        defined_in = self.defined_in
458        assert defined_in
459
460        if defined_in.startswith('q_obj_'):
461            # See QAPISchema._make_implicit_object_type() - reverse the
462            # mapping there to create a nice human-readable description
463            defined_in = defined_in[6:]
464            if defined_in.endswith('-arg'):
465                # Implicit type created for a command's dict 'data'
466                assert role == 'member'
467                role = 'parameter'
468            elif defined_in.endswith('-base'):
469                # Implicit type created for a flat union's dict 'base'
470                role = 'base ' + role
471            else:
472                # Implicit type created for a simple union's branch
473                assert defined_in.endswith('-wrapper')
474                # Unreachable and not implemented
475                assert False
476        elif defined_in.endswith('Kind'):
477            # See QAPISchema._make_implicit_enum_type()
478            # Implicit enum created for simple union's branches
479            assert role == 'value'
480            role = 'branch'
481        elif defined_in != info.defn_name:
482            return "%s '%s' of type '%s'" % (role, self.name, defined_in)
483        return "%s '%s'" % (role, self.name)
484
485
486class QAPISchemaEnumMember(QAPISchemaMember):
487    role = 'value'
488
489
490class QAPISchemaFeature(QAPISchemaMember):
491    role = 'feature'
492
493
494class QAPISchemaObjectTypeMember(QAPISchemaMember):
495    def __init__(self, name, info, typ, optional, ifcond=None):
496        QAPISchemaMember.__init__(self, name, info, ifcond)
497        assert isinstance(typ, str)
498        assert isinstance(optional, bool)
499        self._type_name = typ
500        self.type = None
501        self.optional = optional
502
503    def check(self, schema):
504        assert self.defined_in
505        self.type = schema.resolve_type(self._type_name, self.info,
506                                        self.describe)
507
508
509class QAPISchemaObjectTypeVariants(object):
510    def __init__(self, tag_name, info, tag_member, variants):
511        # Flat unions pass tag_name but not tag_member.
512        # Simple unions and alternates pass tag_member but not tag_name.
513        # After check(), tag_member is always set, and tag_name remains
514        # a reliable witness of being used by a flat union.
515        assert bool(tag_member) != bool(tag_name)
516        assert (isinstance(tag_name, str) or
517                isinstance(tag_member, QAPISchemaObjectTypeMember))
518        for v in variants:
519            assert isinstance(v, QAPISchemaObjectTypeVariant)
520        self._tag_name = tag_name
521        self.info = info
522        self.tag_member = tag_member
523        self.variants = variants
524
525    def set_defined_in(self, name):
526        for v in self.variants:
527            v.set_defined_in(name)
528
529    def check(self, schema, seen):
530        if not self.tag_member: # flat union
531            self.tag_member = seen.get(c_name(self._tag_name))
532            base = "'base'"
533            # Pointing to the base type when not implicit would be
534            # nice, but we don't know it here
535            if not self.tag_member or self._tag_name != self.tag_member.name:
536                raise QAPISemError(
537                    self.info,
538                    "discriminator '%s' is not a member of %s"
539                    % (self._tag_name, base))
540            # Here we do:
541            base_type = schema.lookup_type(self.tag_member.defined_in)
542            assert base_type
543            if not base_type.is_implicit():
544                base = "base type '%s'" % self.tag_member.defined_in
545            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
546                raise QAPISemError(
547                    self.info,
548                    "discriminator member '%s' of %s must be of enum type"
549                    % (self._tag_name, base))
550            if self.tag_member.optional:
551                raise QAPISemError(
552                    self.info,
553                    "discriminator member '%s' of %s must not be optional"
554                    % (self._tag_name, base))
555            if self.tag_member.ifcond:
556                raise QAPISemError(
557                    self.info,
558                    "discriminator member '%s' of %s must not be conditional"
559                    % (self._tag_name, base))
560        else:                   # simple union
561            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
562            assert not self.tag_member.optional
563            assert self.tag_member.ifcond == []
564        if self._tag_name:    # flat union
565            # branches that are not explicitly covered get an empty type
566            cases = set([v.name for v in self.variants])
567            for m in self.tag_member.type.members:
568                if m.name not in cases:
569                    v = QAPISchemaObjectTypeVariant(m.name, self.info,
570                                                    'q_empty', m.ifcond)
571                    v.set_defined_in(self.tag_member.defined_in)
572                    self.variants.append(v)
573        if not self.variants:
574            raise QAPISemError(self.info, "union has no branches")
575        for v in self.variants:
576            v.check(schema)
577            # Union names must match enum values; alternate names are
578            # checked separately. Use 'seen' to tell the two apart.
579            if seen:
580                if v.name not in self.tag_member.type.member_names():
581                    raise QAPISemError(
582                        self.info,
583                        "branch '%s' is not a value of %s"
584                        % (v.name, self.tag_member.type.describe()))
585                if (not isinstance(v.type, QAPISchemaObjectType)
586                        or v.type.variants):
587                    raise QAPISemError(
588                        self.info,
589                        "%s cannot use %s"
590                        % (v.describe(self.info), v.type.describe()))
591                v.type.check(schema)
592
593    def check_clash(self, info, seen):
594        for v in self.variants:
595            # Reset seen map for each variant, since qapi names from one
596            # branch do not affect another branch
597            v.type.check_clash(info, dict(seen))
598
599
600class QAPISchemaObjectTypeVariant(QAPISchemaObjectTypeMember):
601    role = 'branch'
602
603    def __init__(self, name, info, typ, ifcond=None):
604        QAPISchemaObjectTypeMember.__init__(self, name, info, typ,
605                                            False, ifcond)
606
607
608class QAPISchemaAlternateType(QAPISchemaType):
609    meta = 'alternate'
610
611    def __init__(self, name, info, doc, ifcond, variants):
612        QAPISchemaType.__init__(self, name, info, doc, ifcond)
613        assert isinstance(variants, QAPISchemaObjectTypeVariants)
614        assert variants.tag_member
615        variants.set_defined_in(name)
616        variants.tag_member.set_defined_in(self.name)
617        self.variants = variants
618
619    def check(self, schema):
620        QAPISchemaType.check(self, schema)
621        self.variants.tag_member.check(schema)
622        # Not calling self.variants.check_clash(), because there's nothing
623        # to clash with
624        self.variants.check(schema, {})
625        # Alternate branch names have no relation to the tag enum values;
626        # so we have to check for potential name collisions ourselves.
627        seen = {}
628        types_seen = {}
629        for v in self.variants.variants:
630            v.check_clash(self.info, seen)
631            qtype = v.type.alternate_qtype()
632            if not qtype:
633                raise QAPISemError(
634                    self.info,
635                    "%s cannot use %s"
636                    % (v.describe(self.info), v.type.describe()))
637            conflicting = set([qtype])
638            if qtype == 'QTYPE_QSTRING':
639                if isinstance(v.type, QAPISchemaEnumType):
640                    for m in v.type.members:
641                        if m.name in ['on', 'off']:
642                            conflicting.add('QTYPE_QBOOL')
643                        if re.match(r'[-+0-9.]', m.name):
644                            # lazy, could be tightened
645                            conflicting.add('QTYPE_QNUM')
646                else:
647                    conflicting.add('QTYPE_QNUM')
648                    conflicting.add('QTYPE_QBOOL')
649            for qt in conflicting:
650                if qt in types_seen:
651                    raise QAPISemError(
652                        self.info,
653                        "%s can't be distinguished from '%s'"
654                        % (v.describe(self.info), types_seen[qt]))
655                types_seen[qt] = v.name
656
657    def connect_doc(self, doc=None):
658        doc = doc or self.doc
659        if doc:
660            for v in self.variants.variants:
661                doc.connect_member(v)
662
663    def c_type(self):
664        return c_name(self.name) + pointer_suffix
665
666    def json_type(self):
667        return 'value'
668
669    def visit(self, visitor):
670        QAPISchemaType.visit(self, visitor)
671        visitor.visit_alternate_type(self.name, self.info, self.ifcond,
672                                     self.variants)
673
674
675class QAPISchemaCommand(QAPISchemaEntity):
676    meta = 'command'
677
678    def __init__(self, name, info, doc, ifcond, arg_type, ret_type,
679                 gen, success_response, boxed, allow_oob, allow_preconfig,
680                 features):
681        QAPISchemaEntity.__init__(self, name, info, doc, ifcond)
682        assert not arg_type or isinstance(arg_type, str)
683        assert not ret_type or isinstance(ret_type, str)
684        for f in features:
685            assert isinstance(f, QAPISchemaFeature)
686            f.set_defined_in(name)
687        self._arg_type_name = arg_type
688        self.arg_type = None
689        self._ret_type_name = ret_type
690        self.ret_type = None
691        self.gen = gen
692        self.success_response = success_response
693        self.boxed = boxed
694        self.allow_oob = allow_oob
695        self.allow_preconfig = allow_preconfig
696        self.features = features
697
698    def check(self, schema):
699        QAPISchemaEntity.check(self, schema)
700        if self._arg_type_name:
701            self.arg_type = schema.resolve_type(
702                self._arg_type_name, self.info, "command's 'data'")
703            if not isinstance(self.arg_type, QAPISchemaObjectType):
704                raise QAPISemError(
705                    self.info,
706                    "command's 'data' cannot take %s"
707                    % self.arg_type.describe())
708            if self.arg_type.variants and not self.boxed:
709                raise QAPISemError(
710                    self.info,
711                    "command's 'data' can take %s only with 'boxed': true"
712                    % self.arg_type.describe())
713        if self._ret_type_name:
714            self.ret_type = schema.resolve_type(
715                self._ret_type_name, self.info, "command's 'returns'")
716            if self.name not in self.info.pragma.returns_whitelist:
717                if not (isinstance(self.ret_type, QAPISchemaObjectType)
718                        or (isinstance(self.ret_type, QAPISchemaArrayType)
719                            and isinstance(self.ret_type.element_type,
720                                           QAPISchemaObjectType))):
721                    raise QAPISemError(
722                        self.info,
723                        "command's 'returns' cannot take %s"
724                        % self.ret_type.describe())
725
726        # Features are in a name space separate from members
727        seen = {}
728        for f in self.features:
729            f.check_clash(self.info, seen)
730
731    def connect_doc(self, doc=None):
732        doc = doc or self.doc
733        if doc:
734            if self.arg_type and self.arg_type.is_implicit():
735                self.arg_type.connect_doc(doc)
736
737    def visit(self, visitor):
738        QAPISchemaEntity.visit(self, visitor)
739        visitor.visit_command(self.name, self.info, self.ifcond,
740                              self.arg_type, self.ret_type,
741                              self.gen, self.success_response,
742                              self.boxed, self.allow_oob,
743                              self.allow_preconfig,
744                              self.features)
745
746
747class QAPISchemaEvent(QAPISchemaEntity):
748    meta = 'event'
749
750    def __init__(self, name, info, doc, ifcond, arg_type, boxed):
751        QAPISchemaEntity.__init__(self, name, info, doc, ifcond)
752        assert not arg_type or isinstance(arg_type, str)
753        self._arg_type_name = arg_type
754        self.arg_type = None
755        self.boxed = boxed
756
757    def check(self, schema):
758        QAPISchemaEntity.check(self, schema)
759        if self._arg_type_name:
760            self.arg_type = schema.resolve_type(
761                self._arg_type_name, self.info, "event's 'data'")
762            if not isinstance(self.arg_type, QAPISchemaObjectType):
763                raise QAPISemError(
764                    self.info,
765                    "event's 'data' cannot take %s"
766                    % self.arg_type.describe())
767            if self.arg_type.variants and not self.boxed:
768                raise QAPISemError(
769                    self.info,
770                    "event's 'data' can take %s only with 'boxed': true"
771                    % self.arg_type.describe())
772
773    def connect_doc(self, doc=None):
774        doc = doc or self.doc
775        if doc:
776            if self.arg_type and self.arg_type.is_implicit():
777                self.arg_type.connect_doc(doc)
778
779    def visit(self, visitor):
780        QAPISchemaEntity.visit(self, visitor)
781        visitor.visit_event(self.name, self.info, self.ifcond,
782                            self.arg_type, self.boxed)
783
784
785class QAPISchema(object):
786    def __init__(self, fname):
787        self.fname = fname
788        parser = QAPISchemaParser(fname)
789        exprs = check_exprs(parser.exprs)
790        self.docs = parser.docs
791        self._entity_list = []
792        self._entity_dict = {}
793        self._predefining = True
794        self._def_predefineds()
795        self._predefining = False
796        self._def_exprs(exprs)
797        self.check()
798
799    def _def_entity(self, ent):
800        # Only the predefined types are allowed to not have info
801        assert ent.info or self._predefining
802        self._entity_list.append(ent)
803        if ent.name is None:
804            return
805        # TODO reject names that differ only in '_' vs. '.'  vs. '-',
806        # because they're liable to clash in generated C.
807        other_ent = self._entity_dict.get(ent.name)
808        if other_ent:
809            if other_ent.info:
810                where = QAPIError(other_ent.info, None, "previous definition")
811                raise QAPISemError(
812                    ent.info,
813                    "'%s' is already defined\n%s" % (ent.name, where))
814            raise QAPISemError(
815                ent.info, "%s is already defined" % other_ent.describe())
816        self._entity_dict[ent.name] = ent
817
818    def lookup_entity(self, name, typ=None):
819        ent = self._entity_dict.get(name)
820        if typ and not isinstance(ent, typ):
821            return None
822        return ent
823
824    def lookup_type(self, name):
825        return self.lookup_entity(name, QAPISchemaType)
826
827    def resolve_type(self, name, info, what):
828        typ = self.lookup_type(name)
829        if not typ:
830            if callable(what):
831                what = what(info)
832            raise QAPISemError(
833                info, "%s uses unknown type '%s'" % (what, name))
834        return typ
835
836    def _def_include(self, expr, info, doc):
837        include = expr['include']
838        assert doc is None
839        main_info = info
840        while main_info.parent:
841            main_info = main_info.parent
842        fname = os.path.relpath(include, os.path.dirname(main_info.fname))
843        self._def_entity(QAPISchemaInclude(fname, info))
844
845    def _def_builtin_type(self, name, json_type, c_type):
846        self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
847        # Instantiating only the arrays that are actually used would
848        # be nice, but we can't as long as their generated code
849        # (qapi-builtin-types.[ch]) may be shared by some other
850        # schema.
851        self._make_array_type(name, None)
852
853    def _def_predefineds(self):
854        for t in [('str',    'string',  'char' + pointer_suffix),
855                  ('number', 'number',  'double'),
856                  ('int',    'int',     'int64_t'),
857                  ('int8',   'int',     'int8_t'),
858                  ('int16',  'int',     'int16_t'),
859                  ('int32',  'int',     'int32_t'),
860                  ('int64',  'int',     'int64_t'),
861                  ('uint8',  'int',     'uint8_t'),
862                  ('uint16', 'int',     'uint16_t'),
863                  ('uint32', 'int',     'uint32_t'),
864                  ('uint64', 'int',     'uint64_t'),
865                  ('size',   'int',     'uint64_t'),
866                  ('bool',   'boolean', 'bool'),
867                  ('any',    'value',   'QObject' + pointer_suffix),
868                  ('null',   'null',    'QNull' + pointer_suffix)]:
869            self._def_builtin_type(*t)
870        self.the_empty_object_type = QAPISchemaObjectType(
871            'q_empty', None, None, None, None, [], None, [])
872        self._def_entity(self.the_empty_object_type)
873
874        qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
875                  'qbool']
876        qtype_values = self._make_enum_members(
877            [{'name': n} for n in qtypes], None)
878
879        self._def_entity(QAPISchemaEnumType('QType', None, None, None,
880                                            qtype_values, 'QTYPE'))
881
882    def _make_features(self, features, info):
883        return [QAPISchemaFeature(f['name'], info, f.get('if'))
884                for f in features]
885
886    def _make_enum_members(self, values, info):
887        return [QAPISchemaEnumMember(v['name'], info, v.get('if'))
888                for v in values]
889
890    def _make_implicit_enum_type(self, name, info, ifcond, values):
891        # See also QAPISchemaObjectTypeMember.describe()
892        name = name + 'Kind'    # reserved by check_defn_name_str()
893        self._def_entity(QAPISchemaEnumType(
894            name, info, None, ifcond, self._make_enum_members(values, info),
895            None))
896        return name
897
898    def _make_array_type(self, element_type, info):
899        name = element_type + 'List'    # reserved by check_defn_name_str()
900        if not self.lookup_type(name):
901            self._def_entity(QAPISchemaArrayType(name, info, element_type))
902        return name
903
904    def _make_implicit_object_type(self, name, info, ifcond, role, members):
905        if not members:
906            return None
907        # See also QAPISchemaObjectTypeMember.describe()
908        name = 'q_obj_%s-%s' % (name, role)
909        typ = self.lookup_entity(name, QAPISchemaObjectType)
910        if typ:
911            # The implicit object type has multiple users.  This can
912            # happen only for simple unions' implicit wrapper types.
913            # Its ifcond should be the disjunction of its user's
914            # ifconds.  Not implemented.  Instead, we always pass the
915            # wrapped type's ifcond, which is trivially the same for all
916            # users.  It's also necessary for the wrapper to compile.
917            # But it's not tight: the disjunction need not imply it.  We
918            # may end up compiling useless wrapper types.
919            # TODO kill simple unions or implement the disjunction
920            assert (ifcond or []) == typ._ifcond # pylint: disable=protected-access
921        else:
922            self._def_entity(QAPISchemaObjectType(name, info, None, ifcond,
923                                                  None, members, None, []))
924        return name
925
926    def _def_enum_type(self, expr, info, doc):
927        name = expr['enum']
928        data = expr['data']
929        prefix = expr.get('prefix')
930        ifcond = expr.get('if')
931        self._def_entity(QAPISchemaEnumType(
932            name, info, doc, ifcond,
933            self._make_enum_members(data, info), prefix))
934
935    def _make_member(self, name, typ, ifcond, info):
936        optional = False
937        if name.startswith('*'):
938            name = name[1:]
939            optional = True
940        if isinstance(typ, list):
941            assert len(typ) == 1
942            typ = self._make_array_type(typ[0], info)
943        return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond)
944
945    def _make_members(self, data, info):
946        return [self._make_member(key, value['type'], value.get('if'), info)
947                for (key, value) in data.items()]
948
949    def _def_struct_type(self, expr, info, doc):
950        name = expr['struct']
951        base = expr.get('base')
952        data = expr['data']
953        ifcond = expr.get('if')
954        features = expr.get('features', [])
955        self._def_entity(QAPISchemaObjectType(
956            name, info, doc, ifcond, base,
957            self._make_members(data, info),
958            None,
959            self._make_features(features, info)))
960
961    def _make_variant(self, case, typ, ifcond, info):
962        return QAPISchemaObjectTypeVariant(case, info, typ, ifcond)
963
964    def _make_simple_variant(self, case, typ, ifcond, info):
965        if isinstance(typ, list):
966            assert len(typ) == 1
967            typ = self._make_array_type(typ[0], info)
968        typ = self._make_implicit_object_type(
969            typ, info, self.lookup_type(typ),
970            'wrapper', [self._make_member('data', typ, None, info)])
971        return QAPISchemaObjectTypeVariant(case, info, typ, ifcond)
972
973    def _def_union_type(self, expr, info, doc):
974        name = expr['union']
975        data = expr['data']
976        base = expr.get('base')
977        ifcond = expr.get('if')
978        tag_name = expr.get('discriminator')
979        tag_member = None
980        if isinstance(base, dict):
981            base = self._make_implicit_object_type(
982                name, info, ifcond,
983                'base', self._make_members(base, info))
984        if tag_name:
985            variants = [self._make_variant(key, value['type'],
986                                           value.get('if'), info)
987                        for (key, value) in data.items()]
988            members = []
989        else:
990            variants = [self._make_simple_variant(key, value['type'],
991                                                  value.get('if'), info)
992                        for (key, value) in data.items()]
993            enum = [{'name': v.name, 'if': v.ifcond} for v in variants]
994            typ = self._make_implicit_enum_type(name, info, ifcond, enum)
995            tag_member = QAPISchemaObjectTypeMember('type', info, typ, False)
996            members = [tag_member]
997        self._def_entity(
998            QAPISchemaObjectType(name, info, doc, ifcond, base, members,
999                                 QAPISchemaObjectTypeVariants(
1000                                     tag_name, info, tag_member, variants),
1001                                 []))
1002
1003    def _def_alternate_type(self, expr, info, doc):
1004        name = expr['alternate']
1005        data = expr['data']
1006        ifcond = expr.get('if')
1007        variants = [self._make_variant(key, value['type'], value.get('if'),
1008                                       info)
1009                    for (key, value) in data.items()]
1010        tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1011        self._def_entity(
1012            QAPISchemaAlternateType(name, info, doc, ifcond,
1013                                    QAPISchemaObjectTypeVariants(
1014                                        None, info, tag_member, variants)))
1015
1016    def _def_command(self, expr, info, doc):
1017        name = expr['command']
1018        data = expr.get('data')
1019        rets = expr.get('returns')
1020        gen = expr.get('gen', True)
1021        success_response = expr.get('success-response', True)
1022        boxed = expr.get('boxed', False)
1023        allow_oob = expr.get('allow-oob', False)
1024        allow_preconfig = expr.get('allow-preconfig', False)
1025        ifcond = expr.get('if')
1026        features = expr.get('features', [])
1027        if isinstance(data, OrderedDict):
1028            data = self._make_implicit_object_type(
1029                name, info, ifcond, 'arg', self._make_members(data, info))
1030        if isinstance(rets, list):
1031            assert len(rets) == 1
1032            rets = self._make_array_type(rets[0], info)
1033        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, data, rets,
1034                                           gen, success_response,
1035                                           boxed, allow_oob, allow_preconfig,
1036                                           self._make_features(features, info)))
1037
1038    def _def_event(self, expr, info, doc):
1039        name = expr['event']
1040        data = expr.get('data')
1041        boxed = expr.get('boxed', False)
1042        ifcond = expr.get('if')
1043        if isinstance(data, OrderedDict):
1044            data = self._make_implicit_object_type(
1045                name, info, ifcond, 'arg', self._make_members(data, info))
1046        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, data, boxed))
1047
1048    def _def_exprs(self, exprs):
1049        for expr_elem in exprs:
1050            expr = expr_elem['expr']
1051            info = expr_elem['info']
1052            doc = expr_elem.get('doc')
1053            if 'enum' in expr:
1054                self._def_enum_type(expr, info, doc)
1055            elif 'struct' in expr:
1056                self._def_struct_type(expr, info, doc)
1057            elif 'union' in expr:
1058                self._def_union_type(expr, info, doc)
1059            elif 'alternate' in expr:
1060                self._def_alternate_type(expr, info, doc)
1061            elif 'command' in expr:
1062                self._def_command(expr, info, doc)
1063            elif 'event' in expr:
1064                self._def_event(expr, info, doc)
1065            elif 'include' in expr:
1066                self._def_include(expr, info, doc)
1067            else:
1068                assert False
1069
1070    def check(self):
1071        for ent in self._entity_list:
1072            ent.check(self)
1073            ent.connect_doc()
1074            ent.check_doc()
1075
1076    def visit(self, visitor):
1077        visitor.visit_begin(self)
1078        module = None
1079        visitor.visit_module(module)
1080        for entity in self._entity_list:
1081            if visitor.visit_needed(entity):
1082                if entity.module != module:
1083                    module = entity.module
1084                    visitor.visit_module(module)
1085                entity.visit(visitor)
1086        visitor.visit_end()
1087