scripts/qapi/events.py

   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 qapi.common import *
  16 from qapi.gen import QAPISchemaModularCVisitor, ifcontext
  17 from qapi.schema import QAPISchemaEnumMember
  18 from qapi.types import gen_enum, gen_enum_lookup
  19
  20
  21 def build_event_send_proto(name, arg_type, boxed):
  22     return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
  23         'c_name': c_name(name.lower()),
  24         'param': build_params(arg_type, boxed)}
  25
  26
  27 def gen_event_send_decl(name, arg_type, boxed):
  28     return mcgen('''
  29
  30 %(proto)s;
  31 ''',
  32                  proto=build_event_send_proto(name, arg_type, boxed))
  33
  34
  35 # Declare and initialize an object 'qapi' using parameters from build_params()
  36 def gen_param_var(typ):
  37     assert not typ.variants
  38     ret = mcgen('''
  39     %(c_name)s param = {
  40 ''',
  41                 c_name=typ.c_name())
  42     sep = '        '
  43     for memb in typ.members:
  44         ret += sep
  45         sep = ', '
  46         if memb.optional:
  47             ret += 'has_' + c_name(memb.name) + sep
  48         if memb.type.name == 'str':
  49             # Cast away const added in build_params()
  50             ret += '(char *)'
  51         ret += c_name(memb.name)
  52     ret += mcgen('''
  53
  54     };
  55 ''')
  56     if not typ.is_implicit():
  57         ret += mcgen('''
  58     %(c_name)s *arg = &param;
  59 ''',
  60                      c_name=typ.c_name())
  61     return ret
  62
  63
  64 def gen_event_send(name, arg_type, boxed, event_enum_name, event_emit):
  65     # FIXME: Our declaration of local variables (and of 'errp' in the
  66     # parameter list) can collide with exploded members of the event's
  67     # data type passed in as parameters.  If this collision ever hits in
  68     # practice, we can rename our local variables with a leading _ prefix,
  69     # or split the code into a wrapper function that creates a boxed
  70     # 'param' object then calls another to do the real work.
  71     have_args = boxed or (arg_type and not arg_type.is_empty())
  72
  73     ret = mcgen('''
  74
  75 %(proto)s
  76 {
  77     QDict *qmp;
  78 ''',
  79                 proto=build_event_send_proto(name, arg_type, boxed))
  80
  81     if have_args:
  82         ret += mcgen('''
  83     QObject *obj;
  84     Visitor *v;
  85 ''')
  86         if not boxed:
  87             ret += gen_param_var(arg_type)
  88
  89     ret += mcgen('''
  90
  91     qmp = qmp_event_build_dict("%(name)s");
  92
  93 ''',
  94                  name=name)
  95
  96     if have_args:
  97         ret += mcgen('''
  98     v = qobject_output_visitor_new(&obj);
  99 ''')
 100         if not arg_type.is_implicit():
 101             ret += mcgen('''
 102     visit_type_%(c_name)s(v, "%(name)s", &arg, &error_abort);
 103 ''',
 104                          name=name, c_name=arg_type.c_name())
 105         else:
 106             ret += mcgen('''
 107
 108     visit_start_struct(v, "%(name)s", NULL, 0, &error_abort);
 109     visit_type_%(c_name)s_members(v, &param, &error_abort);
 110     visit_check_struct(v, &error_abort);
 111     visit_end_struct(v, NULL);
 112 ''',
 113                          name=name, c_name=arg_type.c_name())
 114         ret += mcgen('''
 115
 116     visit_complete(v, &obj);
 117     qdict_put_obj(qmp, "data", obj);
 118 ''')
 119
 120     ret += mcgen('''
 121     %(event_emit)s(%(c_enum)s, qmp);
 122
 123 ''',
 124                  event_emit=event_emit,
 125                  c_enum=c_enum_const(event_enum_name, name))
 126
 127     if have_args:
 128         ret += mcgen('''
 129     visit_free(v);
 130 ''')
 131     ret += mcgen('''
 132     qobject_unref(qmp);
 133 }
 134 ''')
 135     return ret
 136
 137
 138 class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
 139
 140     def __init__(self, prefix):
 141         QAPISchemaModularCVisitor.__init__(
 142             self, prefix, 'qapi-events',
 143             ' * Schema-defined QAPI/QMP events', __doc__)
 144         self._event_enum_name = c_name(prefix + 'QAPIEvent', protect=False)
 145         self._event_enum_members = []
 146         self._event_emit_name = c_name(prefix + 'qapi_event_emit')
 147
 148     def _begin_user_module(self, name):
 149         events = self._module_basename('qapi-events', name)
 150         types = self._module_basename('qapi-types', name)
 151         visit = self._module_basename('qapi-visit', name)
 152         self._genc.add(mcgen('''
 153 #include "qemu/osdep.h"
 154 #include "%(prefix)sqapi-emit-events.h"
 155 #include "%(events)s.h"
 156 #include "%(visit)s.h"
 157 #include "qapi/error.h"
 158 #include "qapi/qmp/qdict.h"
 159 #include "qapi/qobject-output-visitor.h"
 160 #include "qapi/qmp-event.h"
 161
 162 ''',
 163                              events=events, visit=visit,
 164                              prefix=self._prefix))
 165         self._genh.add(mcgen('''
 166 #include "qapi/util.h"
 167 #include "%(types)s.h"
 168 ''',
 169                              types=types))
 170
 171     def visit_end(self):
 172         self._add_system_module('emit', ' * QAPI Events emission')
 173         self._genc.preamble_add(mcgen('''
 174 #include "qemu/osdep.h"
 175 #include "%(prefix)sqapi-emit-events.h"
 176 ''',
 177                                       prefix=self._prefix))
 178         self._genh.preamble_add(mcgen('''
 179 #include "qapi/util.h"
 180 '''))
 181         self._genh.add(gen_enum(self._event_enum_name,
 182                                 self._event_enum_members))
 183         self._genc.add(gen_enum_lookup(self._event_enum_name,
 184                                        self._event_enum_members))
 185         self._genh.add(mcgen('''
 186
 187 void %(event_emit)s(%(event_enum)s event, QDict *qdict);
 188 ''',
 189                              event_emit=self._event_emit_name,
 190                              event_enum=self._event_enum_name))
 191
 192     def visit_event(self, name, info, ifcond, arg_type, boxed):
 193         with ifcontext(ifcond, self._genh, self._genc):
 194             self._genh.add(gen_event_send_decl(name, arg_type, boxed))
 195             self._genc.add(gen_event_send(name, arg_type, boxed,
 196                                           self._event_enum_name,
 197                                           self._event_emit_name))
 198         # Note: we generate the enum member regardless of @ifcond, to
 199         # keep the enumeration usable in target-independent code.
 200         self._event_enum_members.append(QAPISchemaEnumMember(name, None))
 201
 202
 203 def gen_events(schema, output_dir, prefix):
 204     vis = QAPISchemaGenEventVisitor(prefix)
 205     schema.visit(vis)
 206     vis.write(output_dir)