scripts/qapi/schema.py

   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 # pylint: disable=too-many-lines
  16
  17 # TODO catching name collisions in generated code would be nice
  18
  19 from __future__ import annotations
  20
  21 from abc import ABC, abstractmethod
  22 from collections import OrderedDict
  23 import os
  24 import re
  25 from typing import (
  26     Any,
  27     Callable,
  28     Dict,
  29     List,
  30     Optional,
  31     Union,
  32     cast,
  33 )
  34
  35 from .common import (
  36     POINTER_SUFFIX,
  37     c_name,
  38     cgen_ifcond,
  39     docgen_ifcond,
  40     gen_endif,
  41     gen_if,
  42 )
  43 from .error import QAPIError, QAPISemError, QAPISourceError
  44 from .expr import check_exprs
  45 from .parser import QAPIDoc, QAPIExpression, QAPISchemaParser
  46 from .source import QAPISourceInfo
  47
  48
  49 class QAPISchemaIfCond:
  50     def __init__(
  51         self,
  52         ifcond: Optional[Union[str, Dict[str, object]]] = None,
  53     ) -> None:
  54         self.ifcond = ifcond
  55
  56     def _cgen(self) -> str:
  57         return cgen_ifcond(self.ifcond)
  58
  59     def gen_if(self) -> str:
  60         return gen_if(self._cgen())
  61
  62     def gen_endif(self) -> str:
  63         return gen_endif(self._cgen())
  64
  65     def docgen(self) -> str:
  66         return docgen_ifcond(self.ifcond)
  67
  68     def is_present(self) -> bool:
  69         return bool(self.ifcond)
  70
  71
  72 class QAPISchemaEntity:
  73     """
  74     A schema entity.
  75
  76     This is either a directive, such as include, or a definition.
  77     The latter uses sub-class `QAPISchemaDefinition`.
  78     """
  79     def __init__(self, info: Optional[QAPISourceInfo]):
  80         self._module: Optional[QAPISchemaModule] = None
  81         # For explicitly defined entities, info points to the (explicit)
  82         # definition.  For builtins (and their arrays), info is None.
  83         # For implicitly defined entities, info points to a place that
  84         # triggered the implicit definition (there may be more than one
  85         # such place).
  86         self.info = info
  87         self._checked = False
  88
  89     def __repr__(self) -> str:
  90         return "<%s at 0x%x>" % (type(self).__name__, id(self))
  91
  92     def check(self, schema: QAPISchema) -> None:
  93         # pylint: disable=unused-argument
  94         self._checked = True
  95
  96     def connect_doc(self, doc: Optional[QAPIDoc] = None) -> None:
  97         pass
  98
  99     def _set_module(
 100         self, schema: QAPISchema, info: Optional[QAPISourceInfo]
 101     ) -> None:
 102         assert self._checked
 103         fname = info.fname if info else QAPISchemaModule.BUILTIN_MODULE_NAME
 104         self._module = schema.module_by_fname(fname)
 105         self._module.add_entity(self)
 106
 107     def set_module(self, schema: QAPISchema) -> None:
 108         self._set_module(schema, self.info)
 109
 110     def visit(self, visitor: QAPISchemaVisitor) -> None:
 111         # pylint: disable=unused-argument
 112         assert self._checked
 113
 114
 115 class QAPISchemaDefinition(QAPISchemaEntity):
 116     meta: str
 117
 118     def __init__(
 119         self,
 120         name: str,
 121         info: Optional[QAPISourceInfo],
 122         doc: Optional[QAPIDoc],
 123         ifcond: Optional[QAPISchemaIfCond] = None,
 124         features: Optional[List[QAPISchemaFeature]] = None,
 125     ):
 126         super().__init__(info)
 127         for f in features or []:
 128             f.set_defined_in(name)
 129         self.name = name
 130         self.doc = doc
 131         self._ifcond = ifcond or QAPISchemaIfCond()
 132         self.features = features or []
 133
 134     def __repr__(self) -> str:
 135         return "<%s:%s at 0x%x>" % (type(self).__name__, self.name,
 136                                     id(self))
 137
 138     def c_name(self) -> str:
 139         return c_name(self.name)
 140
 141     def check(self, schema: QAPISchema) -> None:
 142         assert not self._checked
 143         super().check(schema)
 144         seen: Dict[str, QAPISchemaMember] = {}
 145         for f in self.features:
 146             f.check_clash(self.info, seen)
 147
 148     def connect_doc(self, doc: Optional[QAPIDoc] = None) -> None:
 149         super().connect_doc(doc)
 150         doc = doc or self.doc
 151         if doc:
 152             for f in self.features:
 153                 doc.connect_feature(f)
 154
 155     @property
 156     def ifcond(self) -> QAPISchemaIfCond:
 157         assert self._checked
 158         return self._ifcond
 159
 160     def is_implicit(self) -> bool:
 161         return not self.info
 162
 163     def describe(self) -> str:
 164         return "%s '%s'" % (self.meta, self.name)
 165
 166
 167 class QAPISchemaVisitor:
 168     def visit_begin(self, schema: QAPISchema) -> None:
 169         pass
 170
 171     def visit_end(self) -> None:
 172         pass
 173
 174     def visit_module(self, name: str) -> None:
 175         pass
 176
 177     def visit_needed(self, entity: QAPISchemaEntity) -> bool:
 178         # pylint: disable=unused-argument
 179         # Default to visiting everything
 180         return True
 181
 182     def visit_include(self, name: str, info: Optional[QAPISourceInfo]) -> None:
 183         pass
 184
 185     def visit_builtin_type(
 186         self, name: str, info: Optional[QAPISourceInfo], json_type: str
 187     ) -> None:
 188         pass
 189
 190     def visit_enum_type(
 191         self,
 192         name: str,
 193         info: Optional[QAPISourceInfo],
 194         ifcond: QAPISchemaIfCond,
 195         features: List[QAPISchemaFeature],
 196         members: List[QAPISchemaEnumMember],
 197         prefix: Optional[str],
 198     ) -> None:
 199         pass
 200
 201     def visit_array_type(
 202         self,
 203         name: str,
 204         info: Optional[QAPISourceInfo],
 205         ifcond: QAPISchemaIfCond,
 206         element_type: QAPISchemaType,
 207     ) -> None:
 208         pass
 209
 210     def visit_object_type(
 211         self,
 212         name: str,
 213         info: Optional[QAPISourceInfo],
 214         ifcond: QAPISchemaIfCond,
 215         features: List[QAPISchemaFeature],
 216         base: Optional[QAPISchemaObjectType],
 217         members: List[QAPISchemaObjectTypeMember],
 218         branches: Optional[QAPISchemaBranches],
 219     ) -> None:
 220         pass
 221
 222     def visit_object_type_flat(
 223         self,
 224         name: str,
 225         info: Optional[QAPISourceInfo],
 226         ifcond: QAPISchemaIfCond,
 227         features: List[QAPISchemaFeature],
 228         members: List[QAPISchemaObjectTypeMember],
 229         branches: Optional[QAPISchemaBranches],
 230     ) -> None:
 231         pass
 232
 233     def visit_alternate_type(
 234         self,
 235         name: str,
 236         info: Optional[QAPISourceInfo],
 237         ifcond: QAPISchemaIfCond,
 238         features: List[QAPISchemaFeature],
 239         alternatives: QAPISchemaAlternatives,
 240     ) -> None:
 241         pass
 242
 243     def visit_command(
 244         self,
 245         name: str,
 246         info: Optional[QAPISourceInfo],
 247         ifcond: QAPISchemaIfCond,
 248         features: List[QAPISchemaFeature],
 249         arg_type: Optional[QAPISchemaObjectType],
 250         ret_type: Optional[QAPISchemaType],
 251         gen: bool,
 252         success_response: bool,
 253         boxed: bool,
 254         allow_oob: bool,
 255         allow_preconfig: bool,
 256         coroutine: bool,
 257     ) -> None:
 258         pass
 259
 260     def visit_event(
 261         self,
 262         name: str,
 263         info: Optional[QAPISourceInfo],
 264         ifcond: QAPISchemaIfCond,
 265         features: List[QAPISchemaFeature],
 266         arg_type: Optional[QAPISchemaObjectType],
 267         boxed: bool,
 268     ) -> None:
 269         pass
 270
 271
 272 class QAPISchemaModule:
 273
 274     BUILTIN_MODULE_NAME = './builtin'
 275
 276     def __init__(self, name: str):
 277         self.name = name
 278         self._entity_list: List[QAPISchemaEntity] = []
 279
 280     @staticmethod
 281     def is_system_module(name: str) -> bool:
 282         """
 283         System modules are internally defined modules.
 284
 285         Their names start with the "./" prefix.
 286         """
 287         return name.startswith('./')
 288
 289     @classmethod
 290     def is_user_module(cls, name: str) -> bool:
 291         """
 292         User modules are those defined by the user in qapi JSON files.
 293
 294         They do not start with the "./" prefix.
 295         """
 296         return not cls.is_system_module(name)
 297
 298     @classmethod
 299     def is_builtin_module(cls, name: str) -> bool:
 300         """
 301         The built-in module is a single System module for the built-in types.
 302
 303         It is always "./builtin".
 304         """
 305         return name == cls.BUILTIN_MODULE_NAME
 306
 307     def add_entity(self, ent: QAPISchemaEntity) -> None:
 308         self._entity_list.append(ent)
 309
 310     def visit(self, visitor: QAPISchemaVisitor) -> None:
 311         visitor.visit_module(self.name)
 312         for entity in self._entity_list:
 313             if visitor.visit_needed(entity):
 314                 entity.visit(visitor)
 315
 316
 317 class QAPISchemaInclude(QAPISchemaEntity):
 318     def __init__(self, sub_module: QAPISchemaModule, info: QAPISourceInfo):
 319         super().__init__(info)
 320         self._sub_module = sub_module
 321
 322     def visit(self, visitor: QAPISchemaVisitor) -> None:
 323         super().visit(visitor)
 324         visitor.visit_include(self._sub_module.name, self.info)
 325
 326
 327 class QAPISchemaType(QAPISchemaDefinition, ABC):
 328     # Return the C type for common use.
 329     # For the types we commonly box, this is a pointer type.
 330     @abstractmethod
 331     def c_type(self) -> str:
 332         pass
 333
 334     # Return the C type to be used in a parameter list.
 335     def c_param_type(self) -> str:
 336         return self.c_type()
 337
 338     # Return the C type to be used where we suppress boxing.
 339     def c_unboxed_type(self) -> str:
 340         return self.c_type()
 341
 342     @abstractmethod
 343     def json_type(self) -> str:
 344         pass
 345
 346     def alternate_qtype(self) -> Optional[str]:
 347         json2qtype = {
 348             'null':    'QTYPE_QNULL',
 349             'string':  'QTYPE_QSTRING',
 350             'number':  'QTYPE_QNUM',
 351             'int':     'QTYPE_QNUM',
 352             'boolean': 'QTYPE_QBOOL',
 353             'array':   'QTYPE_QLIST',
 354             'object':  'QTYPE_QDICT'
 355         }
 356         return json2qtype.get(self.json_type())
 357
 358     def doc_type(self) -> Optional[str]:
 359         if self.is_implicit():
 360             return None
 361         return self.name
 362
 363     def need_has_if_optional(self) -> bool:
 364         # When FOO is a pointer, has_FOO == !!FOO, i.e. has_FOO is redundant.
 365         # Except for arrays; see QAPISchemaArrayType.need_has_if_optional().
 366         return not self.c_type().endswith(POINTER_SUFFIX)
 367
 368     def check(self, schema: QAPISchema) -> None:
 369         super().check(schema)
 370         for feat in self.features:
 371             if feat.is_special():
 372                 raise QAPISemError(
 373                     self.info,
 374                     f"feature '{feat.name}' is not supported for types")
 375
 376     def describe(self) -> str:
 377         return "%s type '%s'" % (self.meta, self.name)
 378
 379
 380 class QAPISchemaBuiltinType(QAPISchemaType):
 381     meta = 'built-in'
 382
 383     def __init__(self, name: str, json_type: str, c_type: str):
 384         super().__init__(name, None, None)
 385         assert json_type in ('string', 'number', 'int', 'boolean', 'null',
 386                              'value')
 387         self._json_type_name = json_type
 388         self._c_type_name = c_type
 389
 390     def c_name(self) -> str:
 391         return self.name
 392
 393     def c_type(self) -> str:
 394         return self._c_type_name
 395
 396     def c_param_type(self) -> str:
 397         if self.name == 'str':
 398             return 'const ' + self._c_type_name
 399         return self._c_type_name
 400
 401     def json_type(self) -> str:
 402         return self._json_type_name
 403
 404     def doc_type(self) -> str:
 405         return self.json_type()
 406
 407     def visit(self, visitor: QAPISchemaVisitor) -> None:
 408         super().visit(visitor)
 409         visitor.visit_builtin_type(self.name, self.info, self.json_type())
 410
 411
 412 class QAPISchemaEnumType(QAPISchemaType):
 413     meta = 'enum'
 414
 415     def __init__(
 416         self,
 417         name: str,
 418         info: Optional[QAPISourceInfo],
 419         doc: Optional[QAPIDoc],
 420         ifcond: Optional[QAPISchemaIfCond],
 421         features: Optional[List[QAPISchemaFeature]],
 422         members: List[QAPISchemaEnumMember],
 423         prefix: Optional[str],
 424     ):
 425         super().__init__(name, info, doc, ifcond, features)
 426         for m in members:
 427             m.set_defined_in(name)
 428         self.members = members
 429         self.prefix = prefix
 430
 431     def check(self, schema: QAPISchema) -> None:
 432         super().check(schema)
 433         seen: Dict[str, QAPISchemaMember] = {}
 434         for m in self.members:
 435             m.check_clash(self.info, seen)
 436
 437     def connect_doc(self, doc: Optional[QAPIDoc] = None) -> None:
 438         super().connect_doc(doc)
 439         doc = doc or self.doc
 440         for m in self.members:
 441             m.connect_doc(doc)
 442
 443     def is_implicit(self) -> bool:
 444         # See QAPISchema._def_predefineds()
 445         return self.name == 'QType'
 446
 447     def c_type(self) -> str:
 448         return c_name(self.name)
 449
 450     def member_names(self) -> List[str]:
 451         return [m.name for m in self.members]
 452
 453     def json_type(self) -> str:
 454         return 'string'
 455
 456     def visit(self, visitor: QAPISchemaVisitor) -> None:
 457         super().visit(visitor)
 458         visitor.visit_enum_type(
 459             self.name, self.info, self.ifcond, self.features,
 460             self.members, self.prefix)
 461
 462
 463 class QAPISchemaArrayType(QAPISchemaType):
 464     meta = 'array'
 465
 466     def __init__(
 467         self, name: str, info: Optional[QAPISourceInfo], element_type: str
 468     ):
 469         super().__init__(name, info, None)
 470         self._element_type_name = element_type
 471         self.element_type: QAPISchemaType
 472
 473     def need_has_if_optional(self) -> bool:
 474         # When FOO is an array, we still need has_FOO to distinguish
 475         # absent (!has_FOO) from present and empty (has_FOO && !FOO).
 476         return True
 477
 478     def check(self, schema: QAPISchema) -> None:
 479         super().check(schema)
 480         self.element_type = schema.resolve_type(
 481             self._element_type_name, self.info,
 482             self.info.defn_meta if self.info else None)
 483         assert not isinstance(self.element_type, QAPISchemaArrayType)
 484
 485     def set_module(self, schema: QAPISchema) -> None:
 486         self._set_module(schema, self.element_type.info)
 487
 488     @property
 489     def ifcond(self) -> QAPISchemaIfCond:
 490         assert self._checked
 491         return self.element_type.ifcond
 492
 493     def is_implicit(self) -> bool:
 494         return True
 495
 496     def c_type(self) -> str:
 497         return c_name(self.name) + POINTER_SUFFIX
 498
 499     def json_type(self) -> str:
 500         return 'array'
 501
 502     def doc_type(self) -> Optional[str]:
 503         elt_doc_type = self.element_type.doc_type()
 504         if not elt_doc_type:
 505             return None
 506         return 'array of ' + elt_doc_type
 507
 508     def visit(self, visitor: QAPISchemaVisitor) -> None:
 509         super().visit(visitor)
 510         visitor.visit_array_type(self.name, self.info, self.ifcond,
 511                                  self.element_type)
 512
 513     def describe(self) -> str:
 514         return "%s type ['%s']" % (self.meta, self._element_type_name)
 515
 516
 517 class QAPISchemaObjectType(QAPISchemaType):
 518     def __init__(
 519         self,
 520         name: str,
 521         info: Optional[QAPISourceInfo],
 522         doc: Optional[QAPIDoc],
 523         ifcond: Optional[QAPISchemaIfCond],
 524         features: Optional[List[QAPISchemaFeature]],
 525         base: Optional[str],
 526         local_members: List[QAPISchemaObjectTypeMember],
 527         branches: Optional[QAPISchemaBranches],
 528     ):
 529         # struct has local_members, optional base, and no branches
 530         # union has base, branches, and no local_members
 531         super().__init__(name, info, doc, ifcond, features)
 532         self.meta = 'union' if branches else 'struct'
 533         for m in local_members:
 534             m.set_defined_in(name)
 535         if branches is not None:
 536             branches.set_defined_in(name)
 537         self._base_name = base
 538         self.base = None
 539         self.local_members = local_members
 540         self.branches = branches
 541         self.members: List[QAPISchemaObjectTypeMember]
 542         self._check_complete = False
 543
 544     def check(self, schema: QAPISchema) -> None:
 545         # This calls another type T's .check() exactly when the C
 546         # struct emitted by gen_object() contains that T's C struct
 547         # (pointers don't count).
 548         if self._check_complete:
 549             # A previous .check() completed: nothing to do
 550             return
 551         if self._checked:
 552             # Recursed: C struct contains itself
 553             raise QAPISemError(self.info,
 554                                "object %s contains itself" % self.name)
 555
 556         super().check(schema)
 557         assert self._checked and not self._check_complete
 558
 559         seen = OrderedDict()
 560         if self._base_name:
 561             self.base = schema.resolve_type(self._base_name, self.info,
 562                                             "'base'")
 563             if (not isinstance(self.base, QAPISchemaObjectType)
 564                     or self.base.branches):
 565                 raise QAPISemError(
 566                     self.info,
 567                     "'base' requires a struct type, %s isn't"
 568                     % self.base.describe())
 569             self.base.check(schema)
 570             self.base.check_clash(self.info, seen)
 571         for m in self.local_members:
 572             m.check(schema)
 573             m.check_clash(self.info, seen)
 574
 575         # self.check_clash() works in terms of the supertype, but
 576         # self.members is declared List[QAPISchemaObjectTypeMember].
 577         # Cast down to the subtype.
 578         members = cast(List[QAPISchemaObjectTypeMember], list(seen.values()))
 579
 580         if self.branches:
 581             self.branches.check(schema, seen)
 582             self.branches.check_clash(self.info, seen)
 583
 584         self.members = members
 585         self._check_complete = True  # mark completed
 586
 587     # Check that the members of this type do not cause duplicate JSON members,
 588     # and update seen to track the members seen so far. Report any errors
 589     # on behalf of info, which is not necessarily self.info
 590     def check_clash(
 591         self,
 592         info: Optional[QAPISourceInfo],
 593         seen: Dict[str, QAPISchemaMember],
 594     ) -> None:
 595         assert self._checked
 596         for m in self.members:
 597             m.check_clash(info, seen)
 598         if self.branches:
 599             self.branches.check_clash(info, seen)
 600
 601     def connect_doc(self, doc: Optional[QAPIDoc] = None) -> None:
 602         super().connect_doc(doc)
 603         doc = doc or self.doc
 604         if self.base and self.base.is_implicit():
 605             self.base.connect_doc(doc)
 606         for m in self.local_members:
 607             m.connect_doc(doc)
 608
 609     def is_implicit(self) -> bool:
 610         # See QAPISchema._make_implicit_object_type(), as well as
 611         # _def_predefineds()
 612         return self.name.startswith('q_')
 613
 614     def is_empty(self) -> bool:
 615         return not self.members and not self.branches
 616
 617     def has_conditional_members(self) -> bool:
 618         return any(m.ifcond.is_present() for m in self.members)
 619
 620     def c_name(self) -> str:
 621         assert self.name != 'q_empty'
 622         return super().c_name()
 623
 624     def c_type(self) -> str:
 625         assert not self.is_implicit()
 626         return c_name(self.name) + POINTER_SUFFIX
 627
 628     def c_unboxed_type(self) -> str:
 629         return c_name(self.name)
 630
 631     def json_type(self) -> str:
 632         return 'object'
 633
 634     def visit(self, visitor: QAPISchemaVisitor) -> None:
 635         super().visit(visitor)
 636         visitor.visit_object_type(
 637             self.name, self.info, self.ifcond, self.features,
 638             self.base, self.local_members, self.branches)
 639         visitor.visit_object_type_flat(
 640             self.name, self.info, self.ifcond, self.features,
 641             self.members, self.branches)
 642
 643
 644 class QAPISchemaAlternateType(QAPISchemaType):
 645     meta = 'alternate'
 646
 647     def __init__(
 648         self,
 649         name: str,
 650         info: QAPISourceInfo,
 651         doc: Optional[QAPIDoc],
 652         ifcond: Optional[QAPISchemaIfCond],
 653         features: List[QAPISchemaFeature],
 654         alternatives: QAPISchemaAlternatives,
 655     ):
 656         super().__init__(name, info, doc, ifcond, features)
 657         assert alternatives.tag_member
 658         alternatives.set_defined_in(name)
 659         alternatives.tag_member.set_defined_in(self.name)
 660         self.alternatives = alternatives
 661
 662     def check(self, schema: QAPISchema) -> None:
 663         super().check(schema)
 664         self.alternatives.tag_member.check(schema)
 665         # Not calling self.alternatives.check_clash(), because there's
 666         # nothing to clash with
 667         self.alternatives.check(schema, {})
 668         # Alternate branch names have no relation to the tag enum values;
 669         # so we have to check for potential name collisions ourselves.
 670         seen: Dict[str, QAPISchemaMember] = {}
 671         types_seen: Dict[str, str] = {}
 672         for v in self.alternatives.variants:
 673             v.check_clash(self.info, seen)
 674             qtype = v.type.alternate_qtype()
 675             if not qtype:
 676                 raise QAPISemError(
 677                     self.info,
 678                     "%s cannot use %s"
 679                     % (v.describe(self.info), v.type.describe()))
 680             conflicting = set([qtype])
 681             if qtype == 'QTYPE_QSTRING':
 682                 if isinstance(v.type, QAPISchemaEnumType):
 683                     for m in v.type.members:
 684                         if m.name in ['on', 'off']:
 685                             conflicting.add('QTYPE_QBOOL')
 686                         if re.match(r'[-+0-9.]', m.name):
 687                             # lazy, could be tightened
 688                             conflicting.add('QTYPE_QNUM')
 689                 else:
 690                     conflicting.add('QTYPE_QNUM')
 691                     conflicting.add('QTYPE_QBOOL')
 692             for qt in conflicting:
 693                 if qt in types_seen:
 694                     raise QAPISemError(
 695                         self.info,
 696                         "%s can't be distinguished from '%s'"
 697                         % (v.describe(self.info), types_seen[qt]))
 698                 types_seen[qt] = v.name
 699
 700     def connect_doc(self, doc: Optional[QAPIDoc] = None) -> None:
 701         super().connect_doc(doc)
 702         doc = doc or self.doc
 703         for v in self.alternatives.variants:
 704             v.connect_doc(doc)
 705
 706     def c_type(self) -> str:
 707         return c_name(self.name) + POINTER_SUFFIX
 708
 709     def json_type(self) -> str:
 710         return 'value'
 711
 712     def visit(self, visitor: QAPISchemaVisitor) -> None:
 713         super().visit(visitor)
 714         visitor.visit_alternate_type(
 715             self.name, self.info, self.ifcond, self.features,
 716             self.alternatives)
 717
 718
 719 class QAPISchemaVariants:
 720     def __init__(
 721         self,
 722         info: QAPISourceInfo,
 723         variants: List[QAPISchemaVariant],
 724     ):
 725         self.info = info
 726         self.tag_member: QAPISchemaObjectTypeMember
 727         self.variants = variants
 728
 729     def set_defined_in(self, name: str) -> None:
 730         for v in self.variants:
 731             v.set_defined_in(name)
 732
 733     # pylint: disable=unused-argument
 734     def check(
 735             self, schema: QAPISchema, seen: Dict[str, QAPISchemaMember]
 736     ) -> None:
 737         for v in self.variants:
 738             v.check(schema)
 739
 740
 741 class QAPISchemaBranches(QAPISchemaVariants):
 742     def __init__(self,
 743                  info: QAPISourceInfo,
 744                  variants: List[QAPISchemaVariant],
 745                  tag_name: str):
 746         super().__init__(info, variants)
 747         self._tag_name = tag_name
 748
 749     def check(
 750             self, schema: QAPISchema, seen: Dict[str, QAPISchemaMember]
 751     ) -> None:
 752         # We need to narrow the member type:
 753         tag_member = seen.get(c_name(self._tag_name))
 754         assert (tag_member is None
 755                 or isinstance(tag_member, QAPISchemaObjectTypeMember))
 756
 757         base = "'base'"
 758         # Pointing to the base type when not implicit would be
 759         # nice, but we don't know it here
 760         if not tag_member or self._tag_name != tag_member.name:
 761             raise QAPISemError(
 762                 self.info,
 763                 "discriminator '%s' is not a member of %s"
 764                 % (self._tag_name, base))
 765         self.tag_member = tag_member
 766         # Here we do:
 767         assert tag_member.defined_in
 768         base_type = schema.lookup_type(tag_member.defined_in)
 769         assert base_type
 770         if not base_type.is_implicit():
 771             base = "base type '%s'" % tag_member.defined_in
 772         if not isinstance(tag_member.type, QAPISchemaEnumType):
 773             raise QAPISemError(
 774                 self.info,
 775                 "discriminator member '%s' of %s must be of enum type"
 776                 % (self._tag_name, base))
 777         if tag_member.optional:
 778             raise QAPISemError(
 779                 self.info,
 780                 "discriminator member '%s' of %s must not be optional"
 781                 % (self._tag_name, base))
 782         if tag_member.ifcond.is_present():
 783             raise QAPISemError(
 784                 self.info,
 785                 "discriminator member '%s' of %s must not be conditional"
 786                 % (self._tag_name, base))
 787         # branches that are not explicitly covered get an empty type
 788         assert tag_member.defined_in
 789         cases = {v.name for v in self.variants}
 790         for m in tag_member.type.members:
 791             if m.name not in cases:
 792                 v = QAPISchemaVariant(m.name, self.info,
 793                                       'q_empty', m.ifcond)
 794                 v.set_defined_in(tag_member.defined_in)
 795                 self.variants.append(v)
 796         if not self.variants:
 797             raise QAPISemError(self.info, "union has no branches")
 798         for v in self.variants:
 799             v.check(schema)
 800             # Union names must match enum values; alternate names are
 801             # checked separately. Use 'seen' to tell the two apart.
 802             if seen:
 803                 if v.name not in tag_member.type.member_names():
 804                     raise QAPISemError(
 805                         self.info,
 806                         "branch '%s' is not a value of %s"
 807                         % (v.name, tag_member.type.describe()))
 808                 if not isinstance(v.type, QAPISchemaObjectType):
 809                     raise QAPISemError(
 810                         self.info,
 811                         "%s cannot use %s"
 812                         % (v.describe(self.info), v.type.describe()))
 813                 v.type.check(schema)
 814
 815     def check_clash(
 816         self,
 817         info: Optional[QAPISourceInfo],
 818         seen: Dict[str, QAPISchemaMember],
 819     ) -> None:
 820         for v in self.variants:
 821             # Reset seen map for each variant, since qapi names from one
 822             # branch do not affect another branch.
 823             #
 824             # v.type's typing is enforced in check() above.
 825             assert isinstance(v.type, QAPISchemaObjectType)
 826             v.type.check_clash(info, dict(seen))
 827
 828
 829 class QAPISchemaAlternatives(QAPISchemaVariants):
 830     def __init__(self,
 831                  info: QAPISourceInfo,
 832                  variants: List[QAPISchemaVariant],
 833                  tag_member: QAPISchemaObjectTypeMember):
 834         super().__init__(info, variants)
 835         self.tag_member = tag_member
 836
 837     def check(
 838             self, schema: QAPISchema, seen: Dict[str, QAPISchemaMember]
 839     ) -> None:
 840         super().check(schema, seen)
 841         assert isinstance(self.tag_member.type, QAPISchemaEnumType)
 842         assert not self.tag_member.optional
 843         assert not self.tag_member.ifcond.is_present()
 844
 845
 846 class QAPISchemaMember:
 847     """ Represents object members, enum members and features """
 848     role = 'member'
 849
 850     def __init__(
 851         self,
 852         name: str,
 853         info: Optional[QAPISourceInfo],
 854         ifcond: Optional[QAPISchemaIfCond] = None,
 855     ):
 856         self.name = name
 857         self.info = info
 858         self.ifcond = ifcond or QAPISchemaIfCond()
 859         self.defined_in: Optional[str] = None
 860
 861     def set_defined_in(self, name: str) -> None:
 862         assert not self.defined_in
 863         self.defined_in = name
 864
 865     def check_clash(
 866         self,
 867         info: Optional[QAPISourceInfo],
 868         seen: Dict[str, QAPISchemaMember],
 869     ) -> None:
 870         cname = c_name(self.name)
 871         if cname in seen:
 872             raise QAPISemError(
 873                 info,
 874                 "%s collides with %s"
 875                 % (self.describe(info), seen[cname].describe(info)))
 876         seen[cname] = self
 877
 878     def connect_doc(self, doc: Optional[QAPIDoc]) -> None:
 879         if doc:
 880             doc.connect_member(self)
 881
 882     def describe(self, info: Optional[QAPISourceInfo]) -> str:
 883         role = self.role
 884         meta = 'type'
 885         defined_in = self.defined_in
 886         assert defined_in
 887
 888         if defined_in.startswith('q_obj_'):
 889             # See QAPISchema._make_implicit_object_type() - reverse the
 890             # mapping there to create a nice human-readable description
 891             defined_in = defined_in[6:]
 892             if defined_in.endswith('-arg'):
 893                 # Implicit type created for a command's dict 'data'
 894                 assert role == 'member'
 895                 role = 'parameter'
 896                 meta = 'command'
 897                 defined_in = defined_in[:-4]
 898             elif defined_in.endswith('-base'):
 899                 # Implicit type created for a union's dict 'base'
 900                 role = 'base ' + role
 901                 defined_in = defined_in[:-5]
 902             else:
 903                 assert False
 904
 905         assert info is not None
 906         if defined_in != info.defn_name:
 907             return "%s '%s' of %s '%s'" % (role, self.name, meta, defined_in)
 908         return "%s '%s'" % (role, self.name)
 909
 910
 911 class QAPISchemaEnumMember(QAPISchemaMember):
 912     role = 'value'
 913
 914     def __init__(
 915         self,
 916         name: str,
 917         info: Optional[QAPISourceInfo],
 918         ifcond: Optional[QAPISchemaIfCond] = None,
 919         features: Optional[List[QAPISchemaFeature]] = None,
 920     ):
 921         super().__init__(name, info, ifcond)
 922         for f in features or []:
 923             f.set_defined_in(name)
 924         self.features = features or []
 925
 926     def connect_doc(self, doc: Optional[QAPIDoc]) -> None:
 927         super().connect_doc(doc)
 928         if doc:
 929             for f in self.features:
 930                 doc.connect_feature(f)
 931
 932
 933 class QAPISchemaFeature(QAPISchemaMember):
 934     role = 'feature'
 935
 936     def is_special(self) -> bool:
 937         return self.name in ('deprecated', 'unstable')
 938
 939
 940 class QAPISchemaObjectTypeMember(QAPISchemaMember):
 941     def __init__(
 942         self,
 943         name: str,
 944         info: QAPISourceInfo,
 945         typ: str,
 946         optional: bool,
 947         ifcond: Optional[QAPISchemaIfCond] = None,
 948         features: Optional[List[QAPISchemaFeature]] = None,
 949     ):
 950         super().__init__(name, info, ifcond)
 951         for f in features or []:
 952             f.set_defined_in(name)
 953         self._type_name = typ
 954         self.type: QAPISchemaType  # set during check()
 955         self.optional = optional
 956         self.features = features or []
 957
 958     def need_has(self) -> bool:
 959         return self.optional and self.type.need_has_if_optional()
 960
 961     def check(self, schema: QAPISchema) -> None:
 962         assert self.defined_in
 963         self.type = schema.resolve_type(self._type_name, self.info,
 964                                         self.describe)
 965         seen: Dict[str, QAPISchemaMember] = {}
 966         for f in self.features:
 967             f.check_clash(self.info, seen)
 968
 969     def connect_doc(self, doc: Optional[QAPIDoc]) -> None:
 970         super().connect_doc(doc)
 971         if doc:
 972             for f in self.features:
 973                 doc.connect_feature(f)
 974
 975
 976 class QAPISchemaVariant(QAPISchemaObjectTypeMember):
 977     role = 'branch'
 978
 979     def __init__(
 980         self,
 981         name: str,
 982         info: QAPISourceInfo,
 983         typ: str,
 984         ifcond: QAPISchemaIfCond,
 985     ):
 986         super().__init__(name, info, typ, False, ifcond)
 987
 988
 989 class QAPISchemaCommand(QAPISchemaDefinition):
 990     meta = 'command'
 991
 992     def __init__(
 993         self,
 994         name: str,
 995         info: QAPISourceInfo,
 996         doc: Optional[QAPIDoc],
 997         ifcond: QAPISchemaIfCond,
 998         features: List[QAPISchemaFeature],
 999         arg_type: Optional[str],
1000         ret_type: Optional[str],
1001         gen: bool,
1002         success_response: bool,
1003         boxed: bool,
1004         allow_oob: bool,
1005         allow_preconfig: bool,
1006         coroutine: bool,
1007     ):
1008         super().__init__(name, info, doc, ifcond, features)
1009         self._arg_type_name = arg_type
1010         self.arg_type: Optional[QAPISchemaObjectType] = None
1011         self._ret_type_name = ret_type
1012         self.ret_type: Optional[QAPISchemaType] = None
1013         self.gen = gen
1014         self.success_response = success_response
1015         self.boxed = boxed
1016         self.allow_oob = allow_oob
1017         self.allow_preconfig = allow_preconfig
1018         self.coroutine = coroutine
1019
1020     def check(self, schema: QAPISchema) -> None:
1021         assert self.info is not None
1022         super().check(schema)
1023         if self._arg_type_name:
1024             arg_type = schema.resolve_type(
1025                 self._arg_type_name, self.info, "command's 'data'")
1026             if not isinstance(arg_type, QAPISchemaObjectType):
1027                 raise QAPISemError(
1028                     self.info,
1029                     "command's 'data' cannot take %s"
1030                     % arg_type.describe())
1031             self.arg_type = arg_type
1032             if self.arg_type.branches and not self.boxed:
1033                 raise QAPISemError(
1034                     self.info,
1035                     "command's 'data' can take %s only with 'boxed': true"
1036                     % self.arg_type.describe())
1037             self.arg_type.check(schema)
1038             if self.arg_type.has_conditional_members() and not self.boxed:
1039                 raise QAPISemError(
1040                     self.info,
1041                     "conditional command arguments require 'boxed': true")
1042         if self._ret_type_name:
1043             self.ret_type = schema.resolve_type(
1044                 self._ret_type_name, self.info, "command's 'returns'")
1045             if self.name not in self.info.pragma.command_returns_exceptions:
1046                 typ = self.ret_type
1047                 if isinstance(typ, QAPISchemaArrayType):
1048                     typ = typ.element_type
1049                 if not isinstance(typ, QAPISchemaObjectType):
1050                     raise QAPISemError(
1051                         self.info,
1052                         "command's 'returns' cannot take %s"
1053                         % self.ret_type.describe())
1054
1055     def connect_doc(self, doc: Optional[QAPIDoc] = None) -> None:
1056         super().connect_doc(doc)
1057         doc = doc or self.doc
1058         if doc:
1059             if self.arg_type and self.arg_type.is_implicit():
1060                 self.arg_type.connect_doc(doc)
1061
1062     def visit(self, visitor: QAPISchemaVisitor) -> None:
1063         super().visit(visitor)
1064         visitor.visit_command(
1065             self.name, self.info, self.ifcond, self.features,
1066             self.arg_type, self.ret_type, self.gen, self.success_response,
1067             self.boxed, self.allow_oob, self.allow_preconfig,
1068             self.coroutine)
1069
1070
1071 class QAPISchemaEvent(QAPISchemaDefinition):
1072     meta = 'event'
1073
1074     def __init__(
1075         self,
1076         name: str,
1077         info: QAPISourceInfo,
1078         doc: Optional[QAPIDoc],
1079         ifcond: QAPISchemaIfCond,
1080         features: List[QAPISchemaFeature],
1081         arg_type: Optional[str],
1082         boxed: bool,
1083     ):
1084         super().__init__(name, info, doc, ifcond, features)
1085         self._arg_type_name = arg_type
1086         self.arg_type: Optional[QAPISchemaObjectType] = None
1087         self.boxed = boxed
1088
1089     def check(self, schema: QAPISchema) -> None:
1090         super().check(schema)
1091         if self._arg_type_name:
1092             typ = schema.resolve_type(
1093                 self._arg_type_name, self.info, "event's 'data'")
1094             if not isinstance(typ, QAPISchemaObjectType):
1095                 raise QAPISemError(
1096                     self.info,
1097                     "event's 'data' cannot take %s"
1098                     % typ.describe())
1099             self.arg_type = typ
1100             if self.arg_type.branches and not self.boxed:
1101                 raise QAPISemError(
1102                     self.info,
1103                     "event's 'data' can take %s only with 'boxed': true"
1104                     % self.arg_type.describe())
1105             self.arg_type.check(schema)
1106             if self.arg_type.has_conditional_members() and not self.boxed:
1107                 raise QAPISemError(
1108                     self.info,
1109                     "conditional event arguments require 'boxed': true")
1110
1111     def connect_doc(self, doc: Optional[QAPIDoc] = None) -> None:
1112         super().connect_doc(doc)
1113         doc = doc or self.doc
1114         if doc:
1115             if self.arg_type and self.arg_type.is_implicit():
1116                 self.arg_type.connect_doc(doc)
1117
1118     def visit(self, visitor: QAPISchemaVisitor) -> None:
1119         super().visit(visitor)
1120         visitor.visit_event(
1121             self.name, self.info, self.ifcond, self.features,
1122             self.arg_type, self.boxed)
1123
1124
1125 class QAPISchema:
1126     def __init__(self, fname: str):
1127         self.fname = fname
1128
1129         try:
1130             parser = QAPISchemaParser(fname)
1131         except OSError as err:
1132             raise QAPIError(
1133                 f"can't read schema file '{fname}': {err.strerror}"
1134             ) from err
1135
1136         exprs = check_exprs(parser.exprs)
1137         self.docs = parser.docs
1138         self._entity_list: List[QAPISchemaEntity] = []
1139         self._entity_dict: Dict[str, QAPISchemaDefinition] = {}
1140         self._module_dict: Dict[str, QAPISchemaModule] = OrderedDict()
1141         self._schema_dir = os.path.dirname(fname)
1142         self._make_module(QAPISchemaModule.BUILTIN_MODULE_NAME)
1143         self._make_module(fname)
1144         self._predefining = True
1145         self._def_predefineds()
1146         self._predefining = False
1147         self._def_exprs(exprs)
1148         self.check()
1149
1150     def _def_entity(self, ent: QAPISchemaEntity) -> None:
1151         self._entity_list.append(ent)
1152
1153     def _def_definition(self, defn: QAPISchemaDefinition) -> None:
1154         # Only the predefined types are allowed to not have info
1155         assert defn.info or self._predefining
1156         self._def_entity(defn)
1157         # TODO reject names that differ only in '_' vs. '.'  vs. '-',
1158         # because they're liable to clash in generated C.
1159         other_defn = self._entity_dict.get(defn.name)
1160         if other_defn:
1161             if other_defn.info:
1162                 where = QAPISourceError(other_defn.info, "previous definition")
1163                 raise QAPISemError(
1164                     defn.info,
1165                     "'%s' is already defined\n%s" % (defn.name, where))
1166             raise QAPISemError(
1167                 defn.info, "%s is already defined" % other_defn.describe())
1168         self._entity_dict[defn.name] = defn
1169
1170     def lookup_entity(self, name: str) -> Optional[QAPISchemaEntity]:
1171         return self._entity_dict.get(name)
1172
1173     def lookup_type(self, name: str) -> Optional[QAPISchemaType]:
1174         typ = self.lookup_entity(name)
1175         if isinstance(typ, QAPISchemaType):
1176             return typ
1177         return None
1178
1179     def resolve_type(
1180         self,
1181         name: str,
1182         info: Optional[QAPISourceInfo],
1183         what: Union[None, str, Callable[[QAPISourceInfo], str]],
1184     ) -> QAPISchemaType:
1185         typ = self.lookup_type(name)
1186         if not typ:
1187             assert info and what  # built-in types must not fail lookup
1188             if callable(what):
1189                 what = what(info)
1190             raise QAPISemError(
1191                 info, "%s uses unknown type '%s'" % (what, name))
1192         return typ
1193
1194     def _module_name(self, fname: str) -> str:
1195         if QAPISchemaModule.is_system_module(fname):
1196             return fname
1197         return os.path.relpath(fname, self._schema_dir)
1198
1199     def _make_module(self, fname: str) -> QAPISchemaModule:
1200         name = self._module_name(fname)
1201         if name not in self._module_dict:
1202             self._module_dict[name] = QAPISchemaModule(name)
1203         return self._module_dict[name]
1204
1205     def module_by_fname(self, fname: str) -> QAPISchemaModule:
1206         name = self._module_name(fname)
1207         return self._module_dict[name]
1208
1209     def _def_include(self, expr: QAPIExpression) -> None:
1210         include = expr['include']
1211         assert expr.doc is None
1212         self._def_entity(
1213             QAPISchemaInclude(self._make_module(include), expr.info))
1214
1215     def _def_builtin_type(
1216         self, name: str, json_type: str, c_type: str
1217     ) -> None:
1218         self._def_definition(QAPISchemaBuiltinType(name, json_type, c_type))
1219         # Instantiating only the arrays that are actually used would
1220         # be nice, but we can't as long as their generated code
1221         # (qapi-builtin-types.[ch]) may be shared by some other
1222         # schema.
1223         self._make_array_type(name, None)
1224
1225     def _def_predefineds(self) -> None:
1226         for t in [('str',    'string',  'char' + POINTER_SUFFIX),
1227                   ('number', 'number',  'double'),
1228                   ('int',    'int',     'int64_t'),
1229                   ('int8',   'int',     'int8_t'),
1230                   ('int16',  'int',     'int16_t'),
1231                   ('int32',  'int',     'int32_t'),
1232                   ('int64',  'int',     'int64_t'),
1233                   ('uint8',  'int',     'uint8_t'),
1234                   ('uint16', 'int',     'uint16_t'),
1235                   ('uint32', 'int',     'uint32_t'),
1236                   ('uint64', 'int',     'uint64_t'),
1237                   ('size',   'int',     'uint64_t'),
1238                   ('bool',   'boolean', 'bool'),
1239                   ('any',    'value',   'QObject' + POINTER_SUFFIX),
1240                   ('null',   'null',    'QNull' + POINTER_SUFFIX)]:
1241             self._def_builtin_type(*t)
1242         self.the_empty_object_type = QAPISchemaObjectType(
1243             'q_empty', None, None, None, None, None, [], None)
1244         self._def_definition(self.the_empty_object_type)
1245
1246         qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
1247                   'qbool']
1248         qtype_values = self._make_enum_members(
1249             [{'name': n} for n in qtypes], None)
1250
1251         self._def_definition(QAPISchemaEnumType(
1252             'QType', None, None, None, None, qtype_values, 'QTYPE'))
1253
1254     def _make_features(
1255         self,
1256         features: Optional[List[Dict[str, Any]]],
1257         info: Optional[QAPISourceInfo],
1258     ) -> List[QAPISchemaFeature]:
1259         if features is None:
1260             return []
1261         return [QAPISchemaFeature(f['name'], info,
1262                                   QAPISchemaIfCond(f.get('if')))
1263                 for f in features]
1264
1265     def _make_enum_member(
1266         self,
1267         name: str,
1268         ifcond: Optional[Union[str, Dict[str, Any]]],
1269         features: Optional[List[Dict[str, Any]]],
1270         info: Optional[QAPISourceInfo],
1271     ) -> QAPISchemaEnumMember:
1272         return QAPISchemaEnumMember(name, info,
1273                                     QAPISchemaIfCond(ifcond),
1274                                     self._make_features(features, info))
1275
1276     def _make_enum_members(
1277         self, values: List[Dict[str, Any]], info: Optional[QAPISourceInfo]
1278     ) -> List[QAPISchemaEnumMember]:
1279         return [self._make_enum_member(v['name'], v.get('if'),
1280                                        v.get('features'), info)
1281                 for v in values]
1282
1283     def _make_array_type(
1284         self, element_type: str, info: Optional[QAPISourceInfo]
1285     ) -> str:
1286         name = element_type + 'List'    # reserved by check_defn_name_str()
1287         if not self.lookup_type(name):
1288             self._def_definition(QAPISchemaArrayType(
1289                 name, info, element_type))
1290         return name
1291
1292     def _make_implicit_object_type(
1293         self,
1294         name: str,
1295         info: QAPISourceInfo,
1296         ifcond: QAPISchemaIfCond,
1297         role: str,
1298         members: List[QAPISchemaObjectTypeMember],
1299     ) -> Optional[str]:
1300         if not members:
1301             return None
1302         # See also QAPISchemaObjectTypeMember.describe()
1303         name = 'q_obj_%s-%s' % (name, role)
1304         typ = self.lookup_entity(name)
1305         if typ:
1306             assert isinstance(typ, QAPISchemaObjectType)
1307             # The implicit object type has multiple users.  This can
1308             # only be a duplicate definition, which will be flagged
1309             # later.
1310         else:
1311             self._def_definition(QAPISchemaObjectType(
1312                 name, info, None, ifcond, None, None, members, None))
1313         return name
1314
1315     def _def_enum_type(self, expr: QAPIExpression) -> None:
1316         name = expr['enum']
1317         data = expr['data']
1318         prefix = expr.get('prefix')
1319         ifcond = QAPISchemaIfCond(expr.get('if'))
1320         info = expr.info
1321         features = self._make_features(expr.get('features'), info)
1322         self._def_definition(QAPISchemaEnumType(
1323             name, info, expr.doc, ifcond, features,
1324             self._make_enum_members(data, info), prefix))
1325
1326     def _make_member(
1327         self,
1328         name: str,
1329         typ: Union[List[str], str],
1330         ifcond: QAPISchemaIfCond,
1331         features: Optional[List[Dict[str, Any]]],
1332         info: QAPISourceInfo,
1333     ) -> QAPISchemaObjectTypeMember:
1334         optional = False
1335         if name.startswith('*'):
1336             name = name[1:]
1337             optional = True
1338         if isinstance(typ, list):
1339             assert len(typ) == 1
1340             typ = self._make_array_type(typ[0], info)
1341         return QAPISchemaObjectTypeMember(name, info, typ, optional, ifcond,
1342                                           self._make_features(features, info))
1343
1344     def _make_members(
1345         self,
1346         data: Dict[str, Any],
1347         info: QAPISourceInfo,
1348     ) -> List[QAPISchemaObjectTypeMember]:
1349         return [self._make_member(key, value['type'],
1350                                   QAPISchemaIfCond(value.get('if')),
1351                                   value.get('features'), info)
1352                 for (key, value) in data.items()]
1353
1354     def _def_struct_type(self, expr: QAPIExpression) -> None:
1355         name = expr['struct']
1356         base = expr.get('base')
1357         data = expr['data']
1358         info = expr.info
1359         ifcond = QAPISchemaIfCond(expr.get('if'))
1360         features = self._make_features(expr.get('features'), info)
1361         self._def_definition(QAPISchemaObjectType(
1362             name, info, expr.doc, ifcond, features, base,
1363             self._make_members(data, info),
1364             None))
1365
1366     def _make_variant(
1367         self,
1368         case: str,
1369         typ: str,
1370         ifcond: QAPISchemaIfCond,
1371         info: QAPISourceInfo,
1372     ) -> QAPISchemaVariant:
1373         if isinstance(typ, list):
1374             assert len(typ) == 1
1375             typ = self._make_array_type(typ[0], info)
1376         return QAPISchemaVariant(case, info, typ, ifcond)
1377
1378     def _def_union_type(self, expr: QAPIExpression) -> None:
1379         name = expr['union']
1380         base = expr['base']
1381         tag_name = expr['discriminator']
1382         data = expr['data']
1383         assert isinstance(data, dict)
1384         info = expr.info
1385         ifcond = QAPISchemaIfCond(expr.get('if'))
1386         features = self._make_features(expr.get('features'), info)
1387         if isinstance(base, dict):
1388             base = self._make_implicit_object_type(
1389                 name, info, ifcond,
1390                 'base', self._make_members(base, info))
1391         variants = [
1392             self._make_variant(key, value['type'],
1393                                QAPISchemaIfCond(value.get('if')),
1394                                info)
1395             for (key, value) in data.items()]
1396         members: List[QAPISchemaObjectTypeMember] = []
1397         self._def_definition(
1398             QAPISchemaObjectType(name, info, expr.doc, ifcond, features,
1399                                  base, members,
1400                                  QAPISchemaBranches(
1401                                      info, variants, tag_name)))
1402
1403     def _def_alternate_type(self, expr: QAPIExpression) -> None:
1404         name = expr['alternate']
1405         data = expr['data']
1406         assert isinstance(data, dict)
1407         ifcond = QAPISchemaIfCond(expr.get('if'))
1408         info = expr.info
1409         features = self._make_features(expr.get('features'), info)
1410         variants = [
1411             self._make_variant(key, value['type'],
1412                                QAPISchemaIfCond(value.get('if')),
1413                                info)
1414             for (key, value) in data.items()]
1415         tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
1416         self._def_definition(
1417             QAPISchemaAlternateType(
1418                 name, info, expr.doc, ifcond, features,
1419                 QAPISchemaAlternatives(info, variants, tag_member)))
1420
1421     def _def_command(self, expr: QAPIExpression) -> None:
1422         name = expr['command']
1423         data = expr.get('data')
1424         rets = expr.get('returns')
1425         gen = expr.get('gen', True)
1426         success_response = expr.get('success-response', True)
1427         boxed = expr.get('boxed', False)
1428         allow_oob = expr.get('allow-oob', False)
1429         allow_preconfig = expr.get('allow-preconfig', False)
1430         coroutine = expr.get('coroutine', False)
1431         ifcond = QAPISchemaIfCond(expr.get('if'))
1432         info = expr.info
1433         features = self._make_features(expr.get('features'), info)
1434         if isinstance(data, OrderedDict):
1435             data = self._make_implicit_object_type(
1436                 name, info, ifcond,
1437                 'arg', self._make_members(data, info))
1438         if isinstance(rets, list):
1439             assert len(rets) == 1
1440             rets = self._make_array_type(rets[0], info)
1441         self._def_definition(
1442             QAPISchemaCommand(name, info, expr.doc, ifcond, features, data,
1443                               rets, gen, success_response, boxed, allow_oob,
1444                               allow_preconfig, coroutine))
1445
1446     def _def_event(self, expr: QAPIExpression) -> None:
1447         name = expr['event']
1448         data = expr.get('data')
1449         boxed = expr.get('boxed', False)
1450         ifcond = QAPISchemaIfCond(expr.get('if'))
1451         info = expr.info
1452         features = self._make_features(expr.get('features'), info)
1453         if isinstance(data, OrderedDict):
1454             data = self._make_implicit_object_type(
1455                 name, info, ifcond,
1456                 'arg', self._make_members(data, info))
1457         self._def_definition(QAPISchemaEvent(name, info, expr.doc, ifcond,
1458                                              features, data, boxed))
1459
1460     def _def_exprs(self, exprs: List[QAPIExpression]) -> None:
1461         for expr in exprs:
1462             if 'enum' in expr:
1463                 self._def_enum_type(expr)
1464             elif 'struct' in expr:
1465                 self._def_struct_type(expr)
1466             elif 'union' in expr:
1467                 self._def_union_type(expr)
1468             elif 'alternate' in expr:
1469                 self._def_alternate_type(expr)
1470             elif 'command' in expr:
1471                 self._def_command(expr)
1472             elif 'event' in expr:
1473                 self._def_event(expr)
1474             elif 'include' in expr:
1475                 self._def_include(expr)
1476             else:
1477                 assert False
1478
1479     def check(self) -> None:
1480         for ent in self._entity_list:
1481             ent.check(self)
1482             ent.connect_doc()
1483         for ent in self._entity_list:
1484             ent.set_module(self)
1485         for doc in self.docs:
1486             doc.check()
1487
1488     def visit(self, visitor: QAPISchemaVisitor) -> None:
1489         visitor.visit_begin(self)
1490         for mod in self._module_dict.values():
1491             mod.visit(visitor)
1492         visitor.visit_end()