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