events.py (7572B)
1 """ 2 QAPI event generator 3 4 Copyright (c) 2014 Wenchao Xia 5 Copyright (c) 2015-2018 Red Hat Inc. 6 7 Authors: 8 Wenchao Xia <wenchaoqemu@gmail.com> 9 Markus Armbruster <armbru@redhat.com> 10 11 This work is licensed under the terms of the GNU GPL, version 2. 12 See the COPYING file in the top-level directory. 13 """ 14 15 from typing import List, Optional 16 17 from .common import c_enum_const, c_name, mcgen 18 from .gen import QAPISchemaModularCVisitor, build_params, ifcontext 19 from .schema import ( 20 QAPISchema, 21 QAPISchemaEnumMember, 22 QAPISchemaFeature, 23 QAPISchemaIfCond, 24 QAPISchemaObjectType, 25 ) 26 from .source import QAPISourceInfo 27 from .types import gen_enum, gen_enum_lookup 28 29 30 def build_event_send_proto(name: str, 31 arg_type: Optional[QAPISchemaObjectType], 32 boxed: bool) -> str: 33 return 'void qapi_event_send_%(c_name)s(%(param)s)' % { 34 'c_name': c_name(name.lower()), 35 'param': build_params(arg_type, boxed)} 36 37 38 def gen_event_send_decl(name: str, 39 arg_type: Optional[QAPISchemaObjectType], 40 boxed: bool) -> str: 41 return mcgen(''' 42 43 %(proto)s; 44 ''', 45 proto=build_event_send_proto(name, arg_type, boxed)) 46 47 48 def gen_param_var(typ: QAPISchemaObjectType) -> str: 49 """ 50 Generate a struct variable holding the event parameters. 51 52 Initialize it with the function arguments defined in `gen_event_send`. 53 """ 54 assert not typ.variants 55 ret = mcgen(''' 56 %(c_name)s param = { 57 ''', 58 c_name=typ.c_name()) 59 sep = ' ' 60 for memb in typ.members: 61 ret += sep 62 sep = ', ' 63 if memb.optional: 64 ret += 'has_' + c_name(memb.name) + sep 65 if memb.type.name == 'str': 66 # Cast away const added in build_params() 67 ret += '(char *)' 68 ret += c_name(memb.name) 69 ret += mcgen(''' 70 71 }; 72 ''') 73 if not typ.is_implicit(): 74 ret += mcgen(''' 75 %(c_name)s *arg = ¶m; 76 ''', 77 c_name=typ.c_name()) 78 return ret 79 80 81 def gen_event_send(name: str, 82 arg_type: Optional[QAPISchemaObjectType], 83 features: List[QAPISchemaFeature], 84 boxed: bool, 85 event_enum_name: str, 86 event_emit: str) -> str: 87 # FIXME: Our declaration of local variables (and of 'errp' in the 88 # parameter list) can collide with exploded members of the event's 89 # data type passed in as parameters. If this collision ever hits in 90 # practice, we can rename our local variables with a leading _ prefix, 91 # or split the code into a wrapper function that creates a boxed 92 # 'param' object then calls another to do the real work. 93 have_args = boxed or (arg_type and not arg_type.is_empty()) 94 95 ret = mcgen(''' 96 97 %(proto)s 98 { 99 QDict *qmp; 100 ''', 101 proto=build_event_send_proto(name, arg_type, boxed)) 102 103 if have_args: 104 assert arg_type is not None 105 ret += mcgen(''' 106 QObject *obj; 107 Visitor *v; 108 ''') 109 if not boxed: 110 ret += gen_param_var(arg_type) 111 112 for f in features: 113 if f.is_special(): 114 ret += mcgen(''' 115 116 if (compat_policy.%(feat)s_output == COMPAT_POLICY_OUTPUT_HIDE) { 117 return; 118 } 119 ''', 120 feat=f.name) 121 122 ret += mcgen(''' 123 124 qmp = qmp_event_build_dict("%(name)s"); 125 126 ''', 127 name=name) 128 129 if have_args: 130 assert arg_type is not None 131 ret += mcgen(''' 132 v = qobject_output_visitor_new_qmp(&obj); 133 ''') 134 if not arg_type.is_implicit(): 135 ret += mcgen(''' 136 visit_type_%(c_name)s(v, "%(name)s", &arg, &error_abort); 137 ''', 138 name=name, c_name=arg_type.c_name()) 139 else: 140 ret += mcgen(''' 141 142 visit_start_struct(v, "%(name)s", NULL, 0, &error_abort); 143 visit_type_%(c_name)s_members(v, ¶m, &error_abort); 144 visit_check_struct(v, &error_abort); 145 visit_end_struct(v, NULL); 146 ''', 147 name=name, c_name=arg_type.c_name()) 148 ret += mcgen(''' 149 150 visit_complete(v, &obj); 151 if (qdict_size(qobject_to(QDict, obj))) { 152 qdict_put_obj(qmp, "data", obj); 153 } else { 154 qobject_unref(obj); 155 } 156 ''') 157 158 ret += mcgen(''' 159 %(event_emit)s(%(c_enum)s, qmp); 160 161 ''', 162 event_emit=event_emit, 163 c_enum=c_enum_const(event_enum_name, name)) 164 165 if have_args: 166 ret += mcgen(''' 167 visit_free(v); 168 ''') 169 ret += mcgen(''' 170 qobject_unref(qmp); 171 } 172 ''') 173 return ret 174 175 176 class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor): 177 178 def __init__(self, prefix: str): 179 super().__init__( 180 prefix, 'qapi-events', 181 ' * Schema-defined QAPI/QMP events', None, __doc__) 182 self._event_enum_name = c_name(prefix + 'QAPIEvent', protect=False) 183 self._event_enum_members: List[QAPISchemaEnumMember] = [] 184 self._event_emit_name = c_name(prefix + 'qapi_event_emit') 185 186 def _begin_user_module(self, name: str) -> None: 187 events = self._module_basename('qapi-events', name) 188 types = self._module_basename('qapi-types', name) 189 visit = self._module_basename('qapi-visit', name) 190 self._genc.add(mcgen(''' 191 #include "qemu/osdep.h" 192 #include "%(prefix)sqapi-emit-events.h" 193 #include "%(events)s.h" 194 #include "%(visit)s.h" 195 #include "qapi/compat-policy.h" 196 #include "qapi/error.h" 197 #include "qapi/qmp/qdict.h" 198 #include "qapi/qmp-event.h" 199 200 ''', 201 events=events, visit=visit, 202 prefix=self._prefix)) 203 self._genh.add(mcgen(''' 204 #include "qapi/util.h" 205 #include "%(types)s.h" 206 ''', 207 types=types)) 208 209 def visit_end(self) -> None: 210 self._add_module('./emit', ' * QAPI Events emission') 211 self._genc.preamble_add(mcgen(''' 212 #include "qemu/osdep.h" 213 #include "%(prefix)sqapi-emit-events.h" 214 ''', 215 prefix=self._prefix)) 216 self._genh.preamble_add(mcgen(''' 217 #include "qapi/util.h" 218 ''')) 219 self._genh.add(gen_enum(self._event_enum_name, 220 self._event_enum_members)) 221 self._genc.add(gen_enum_lookup(self._event_enum_name, 222 self._event_enum_members)) 223 self._genh.add(mcgen(''' 224 225 void %(event_emit)s(%(event_enum)s event, QDict *qdict); 226 ''', 227 event_emit=self._event_emit_name, 228 event_enum=self._event_enum_name)) 229 230 def visit_event(self, 231 name: str, 232 info: Optional[QAPISourceInfo], 233 ifcond: QAPISchemaIfCond, 234 features: List[QAPISchemaFeature], 235 arg_type: Optional[QAPISchemaObjectType], 236 boxed: bool) -> None: 237 with ifcontext(ifcond, self._genh, self._genc): 238 self._genh.add(gen_event_send_decl(name, arg_type, boxed)) 239 self._genc.add(gen_event_send(name, arg_type, features, boxed, 240 self._event_enum_name, 241 self._event_emit_name)) 242 # Note: we generate the enum member regardless of @ifcond, to 243 # keep the enumeration usable in target-independent code. 244 self._event_enum_members.append(QAPISchemaEnumMember(name, None)) 245 246 247 def gen_events(schema: QAPISchema, 248 output_dir: str, 249 prefix: str) -> None: 250 vis = QAPISchemaGenEventVisitor(prefix) 251 schema.visit(vis) 252 vis.write(output_dir)