1""" 2QAPI introspection generator 3 4Copyright (C) 2015-2018 Red Hat, Inc. 5 6Authors: 7 Markus Armbruster <armbru@redhat.com> 8 9This work is licensed under the terms of the GNU GPL, version 2. 10See the COPYING file in the top-level directory. 11""" 12 13from typing import ( 14 Any, 15 Dict, 16 Generic, 17 Iterable, 18 List, 19 Optional, 20 Tuple, 21 TypeVar, 22 Union, 23) 24 25from .common import ( 26 c_name, 27 gen_endif, 28 gen_if, 29 mcgen, 30) 31from .gen import QAPISchemaMonolithicCVisitor 32from .schema import ( 33 QAPISchemaArrayType, 34 QAPISchemaBuiltinType, 35 QAPISchemaType, 36) 37 38 39# This module constructs a tree data structure that is used to 40# generate the introspection information for QEMU. It is shaped 41# like a JSON value. 42# 43# A complexity over JSON is that our values may or may not be annotated. 44# 45# Un-annotated values may be: 46# Scalar: str, bool, None. 47# Non-scalar: List, Dict 48# _value = Union[str, bool, None, Dict[str, JSONValue], List[JSONValue]] 49# 50# With optional annotations, the type of all values is: 51# JSONValue = Union[_Value, Annotated[_Value]] 52# 53# Sadly, mypy does not support recursive types; so the _Stub alias is used to 54# mark the imprecision in the type model where we'd otherwise use JSONValue. 55_Stub = Any 56_Scalar = Union[str, bool, None] 57_NonScalar = Union[Dict[str, _Stub], List[_Stub]] 58_Value = Union[_Scalar, _NonScalar] 59JSONValue = Union[_Value, 'Annotated[_Value]'] 60 61 62_ValueT = TypeVar('_ValueT', bound=_Value) 63 64 65class Annotated(Generic[_ValueT]): 66 """ 67 Annotated generally contains a SchemaInfo-like type (as a dict), 68 But it also used to wrap comments/ifconds around scalar leaf values, 69 for the benefit of features and enums. 70 """ 71 # TODO: Remove after Python 3.7 adds @dataclass: 72 # pylint: disable=too-few-public-methods 73 def __init__(self, value: _ValueT, ifcond: Iterable[str], 74 comment: Optional[str] = None): 75 self.value = value 76 self.comment: Optional[str] = comment 77 self.ifcond: Tuple[str, ...] = tuple(ifcond) 78 79 80def _tree_to_qlit(obj, level=0, dict_value=False): 81 82 def indent(level): 83 return level * 4 * ' ' 84 85 if isinstance(obj, Annotated): 86 # NB: _tree_to_qlit is called recursively on the values of a 87 # key:value pair; those values can't be decorated with 88 # comments or conditionals. 89 msg = "dict values cannot have attached comments or if-conditionals." 90 assert not dict_value, msg 91 92 ret = '' 93 if obj.comment: 94 ret += indent(level) + f"/* {obj.comment} */\n" 95 if obj.ifcond: 96 ret += gen_if(obj.ifcond) 97 ret += _tree_to_qlit(obj.value, level) 98 if obj.ifcond: 99 ret += '\n' + gen_endif(obj.ifcond) 100 return ret 101 102 ret = '' 103 if not dict_value: 104 ret += indent(level) 105 106 # Scalars: 107 if obj is None: 108 ret += 'QLIT_QNULL' 109 elif isinstance(obj, str): 110 ret += f"QLIT_QSTR({to_c_string(obj)})" 111 elif isinstance(obj, bool): 112 ret += f"QLIT_QBOOL({str(obj).lower()})" 113 114 # Non-scalars: 115 elif isinstance(obj, list): 116 ret += 'QLIT_QLIST(((QLitObject[]) {\n' 117 for value in obj: 118 ret += _tree_to_qlit(value, level + 1).strip('\n') + '\n' 119 ret += indent(level + 1) + '{}\n' 120 ret += indent(level) + '}))' 121 elif isinstance(obj, dict): 122 ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n' 123 for key, value in sorted(obj.items()): 124 ret += indent(level + 1) + "{{ {:s}, {:s} }},\n".format( 125 to_c_string(key), 126 _tree_to_qlit(value, level + 1, dict_value=True) 127 ) 128 ret += indent(level + 1) + '{}\n' 129 ret += indent(level) + '}))' 130 else: 131 raise NotImplementedError( 132 f"type '{type(obj).__name__}' not implemented" 133 ) 134 135 if level > 0: 136 ret += ',' 137 return ret 138 139 140def to_c_string(string): 141 return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"' 142 143 144class QAPISchemaGenIntrospectVisitor(QAPISchemaMonolithicCVisitor): 145 146 def __init__(self, prefix, unmask): 147 super().__init__( 148 prefix, 'qapi-introspect', 149 ' * QAPI/QMP schema introspection', __doc__) 150 self._unmask = unmask 151 self._schema = None 152 self._trees = [] 153 self._used_types = [] 154 self._name_map = {} 155 self._genc.add(mcgen(''' 156#include "qemu/osdep.h" 157#include "%(prefix)sqapi-introspect.h" 158 159''', 160 prefix=prefix)) 161 162 def visit_begin(self, schema): 163 self._schema = schema 164 165 def visit_end(self): 166 # visit the types that are actually used 167 for typ in self._used_types: 168 typ.visit(self) 169 # generate C 170 name = c_name(self._prefix, protect=False) + 'qmp_schema_qlit' 171 self._genh.add(mcgen(''' 172#include "qapi/qmp/qlit.h" 173 174extern const QLitObject %(c_name)s; 175''', 176 c_name=c_name(name))) 177 self._genc.add(mcgen(''' 178const QLitObject %(c_name)s = %(c_string)s; 179''', 180 c_name=c_name(name), 181 c_string=_tree_to_qlit(self._trees))) 182 self._schema = None 183 self._trees = [] 184 self._used_types = [] 185 self._name_map = {} 186 187 def visit_needed(self, entity): 188 # Ignore types on first pass; visit_end() will pick up used types 189 return not isinstance(entity, QAPISchemaType) 190 191 def _name(self, name): 192 if self._unmask: 193 return name 194 if name not in self._name_map: 195 self._name_map[name] = '%d' % len(self._name_map) 196 return self._name_map[name] 197 198 def _use_type(self, typ): 199 assert self._schema is not None 200 201 # Map the various integer types to plain int 202 if typ.json_type() == 'int': 203 typ = self._schema.lookup_type('int') 204 elif (isinstance(typ, QAPISchemaArrayType) and 205 typ.element_type.json_type() == 'int'): 206 typ = self._schema.lookup_type('intList') 207 # Add type to work queue if new 208 if typ not in self._used_types: 209 self._used_types.append(typ) 210 # Clients should examine commands and events, not types. Hide 211 # type names as integers to reduce the temptation. Also, it 212 # saves a few characters on the wire. 213 if isinstance(typ, QAPISchemaBuiltinType): 214 return typ.name 215 if isinstance(typ, QAPISchemaArrayType): 216 return '[' + self._use_type(typ.element_type) + ']' 217 return self._name(typ.name) 218 219 @staticmethod 220 def _gen_features(features): 221 return [Annotated(f.name, f.ifcond) for f in features] 222 223 def _gen_tree(self, name, mtype, obj, ifcond, features): 224 comment: Optional[str] = None 225 if mtype not in ('command', 'event', 'builtin', 'array'): 226 if not self._unmask: 227 # Output a comment to make it easy to map masked names 228 # back to the source when reading the generated output. 229 comment = f'"{self._name(name)}" = {name}' 230 name = self._name(name) 231 obj['name'] = name 232 obj['meta-type'] = mtype 233 if features: 234 obj['features'] = self._gen_features(features) 235 self._trees.append(Annotated(obj, ifcond, comment)) 236 237 def _gen_member(self, member): 238 obj = {'name': member.name, 'type': self._use_type(member.type)} 239 if member.optional: 240 obj['default'] = None 241 if member.features: 242 obj['features'] = self._gen_features(member.features) 243 return Annotated(obj, member.ifcond) 244 245 def _gen_variant(self, variant): 246 obj = {'case': variant.name, 'type': self._use_type(variant.type)} 247 return Annotated(obj, variant.ifcond) 248 249 def visit_builtin_type(self, name, info, json_type): 250 self._gen_tree(name, 'builtin', {'json-type': json_type}, [], None) 251 252 def visit_enum_type(self, name, info, ifcond, features, members, prefix): 253 self._gen_tree( 254 name, 'enum', 255 {'values': [Annotated(m.name, m.ifcond) for m in members]}, 256 ifcond, features 257 ) 258 259 def visit_array_type(self, name, info, ifcond, element_type): 260 element = self._use_type(element_type) 261 self._gen_tree('[' + element + ']', 'array', {'element-type': element}, 262 ifcond, None) 263 264 def visit_object_type_flat(self, name, info, ifcond, features, 265 members, variants): 266 obj = {'members': [self._gen_member(m) for m in members]} 267 if variants: 268 obj['tag'] = variants.tag_member.name 269 obj['variants'] = [self._gen_variant(v) for v in variants.variants] 270 self._gen_tree(name, 'object', obj, ifcond, features) 271 272 def visit_alternate_type(self, name, info, ifcond, features, variants): 273 self._gen_tree( 274 name, 'alternate', 275 {'members': [Annotated({'type': self._use_type(m.type)}, 276 m.ifcond) 277 for m in variants.variants]}, 278 ifcond, features 279 ) 280 281 def visit_command(self, name, info, ifcond, features, 282 arg_type, ret_type, gen, success_response, boxed, 283 allow_oob, allow_preconfig, coroutine): 284 assert self._schema is not None 285 286 arg_type = arg_type or self._schema.the_empty_object_type 287 ret_type = ret_type or self._schema.the_empty_object_type 288 obj = {'arg-type': self._use_type(arg_type), 289 'ret-type': self._use_type(ret_type)} 290 if allow_oob: 291 obj['allow-oob'] = allow_oob 292 self._gen_tree(name, 'command', obj, ifcond, features) 293 294 def visit_event(self, name, info, ifcond, features, arg_type, boxed): 295 assert self._schema is not None 296 arg_type = arg_type or self._schema.the_empty_object_type 297 self._gen_tree(name, 'event', {'arg-type': self._use_type(arg_type)}, 298 ifcond, features) 299 300 301def gen_introspect(schema, output_dir, prefix, opt_unmask): 302 vis = QAPISchemaGenIntrospectVisitor(prefix, opt_unmask) 303 schema.visit(vis) 304 vis.write(output_dir) 305