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
  17
  18 def build_event_send_proto(name, arg_type, boxed):
  19     return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
  20         'c_name': c_name(name.lower()),
  21         'param': build_params(arg_type, boxed)}
  22
  23
  24 def gen_event_send_decl(name, arg_type, boxed):
  25     return mcgen('''
  26
  27 %(proto)s;
  28 ''',
  29                  proto=build_event_send_proto(name, arg_type, boxed))
  30
  31
  32 # Declare and initialize an object 'qapi' using parameters from build_params()
  33 def gen_param_var(typ):
  34     assert not typ.variants
  35     ret = mcgen('''
  36     %(c_name)s param = {
  37 ''',
  38                 c_name=typ.c_name())
  39     sep = '        '
  40     for memb in typ.members:
  41         ret += sep
  42         sep = ', '
  43         if memb.optional:
  44             ret += 'has_' + c_name(memb.name) + sep
  45         if memb.type.name == 'str':
  46             # Cast away const added in build_params()
  47             ret += '(char *)'
  48         ret += c_name(memb.name)
  49     ret += mcgen('''
  50
  51     };
  52 ''')
  53     if not typ.is_implicit():
  54         ret += mcgen('''
  55     %(c_name)s *arg = &param;
  56 ''',
  57                      c_name=typ.c_name())
  58     return ret
  59
  60
  61 def gen_event_send(name, arg_type, boxed, event_enum_name, event_emit):
  62     # FIXME: Our declaration of local variables (and of 'errp' in the
  63     # parameter list) can collide with exploded members of the event's
  64     # data type passed in as parameters.  If this collision ever hits in
  65     # practice, we can rename our local variables with a leading _ prefix,
  66     # or split the code into a wrapper function that creates a boxed
  67     # 'param' object then calls another to do the real work.
  68     ret = mcgen('''
  69
  70 %(proto)s
  71 {
  72     QDict *qmp;
  73 ''',
  74                 proto=build_event_send_proto(name, arg_type, boxed))
  75
  76     if arg_type and not arg_type.is_empty():
  77         ret += mcgen('''
  78     QObject *obj;
  79     Visitor *v;
  80 ''')
  81         if not boxed:
  82             ret += gen_param_var(arg_type)
  83     else:
  84         assert not boxed
  85
  86     ret += mcgen('''
  87
  88     qmp = qmp_event_build_dict("%(name)s");
  89
  90 ''',
  91                  name=name)
  92
  93     if arg_type and not arg_type.is_empty():
  94         ret += mcgen('''
  95     v = qobject_output_visitor_new(&obj);
  96 ''')
  97         if not arg_type.is_implicit():
  98             ret += mcgen('''
  99     visit_type_%(c_name)s(v, "%(name)s", &arg, &error_abort);
 100 ''',
 101                          name=name, c_name=arg_type.c_name())
 102         else:
 103             ret += mcgen('''
 104
 105     visit_start_struct(v, "%(name)s", NULL, 0, &error_abort);
 106     visit_type_%(c_name)s_members(v, &param, &error_abort);
 107     visit_check_struct(v, &error_abort);
 108     visit_end_struct(v, NULL);
 109 ''',
 110                          name=name, c_name=arg_type.c_name())
 111         ret += mcgen('''
 112
 113     visit_complete(v, &obj);
 114     qdict_put_obj(qmp, "data", obj);
 115 ''')
 116
 117     ret += mcgen('''
 118     %(event_emit)s(%(c_enum)s, qmp);
 119
 120 ''',
 121                  event_emit=event_emit,
 122                  c_enum=c_enum_const(event_enum_name, name))
 123
 124     if arg_type and not arg_type.is_empty():
 125         ret += mcgen('''
 126     visit_free(v);
 127 ''')
 128     ret += mcgen('''
 129     qobject_unref(qmp);
 130 }
 131 ''')
 132     return ret
 133
 134
 135 class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
 136
 137     def __init__(self, prefix):
 138         QAPISchemaModularCVisitor.__init__(
 139             self, prefix, 'qapi-events',
 140             ' * Schema-defined QAPI/QMP events', __doc__)
 141         self._event_enum_name = c_name(prefix + 'QAPIEvent', protect=False)
 142         self._event_enum_members = []
 143         self._event_emit_name = c_name(prefix + 'qapi_event_emit')
 144
 145     def _begin_module(self, name):
 146         types = self._module_basename('qapi-types', name)
 147         visit = self._module_basename('qapi-visit', name)
 148         self._genc.add(mcgen('''
 149 #include "qemu/osdep.h"
 150 #include "qemu-common.h"
 151 #include "%(prefix)sqapi-events.h"
 152 #include "%(visit)s.h"
 153 #include "qapi/error.h"
 154 #include "qapi/qmp/qdict.h"
 155 #include "qapi/qobject-output-visitor.h"
 156 #include "qapi/qmp-event.h"
 157
 158 ''',
 159                              visit=visit, prefix=self._prefix))
 160         self._genh.add(mcgen('''
 161 #include "qapi/util.h"
 162 #include "%(types)s.h"
 163
 164 ''',
 165                              types=types))
 166
 167     def visit_end(self):
 168         (genc, genh) = self._module[self._main_module]
 169         genh.add(gen_enum(self._event_enum_name,
 170                           self._event_enum_members))
 171         genc.add(gen_enum_lookup(self._event_enum_name,
 172                                  self._event_enum_members))
 173         genh.add(mcgen('''
 174
 175 void %(event_emit)s(%(event_enum)s event, QDict *qdict);
 176 ''',
 177                        event_emit=self._event_emit_name,
 178                        event_enum=self._event_enum_name))
 179
 180     def visit_event(self, name, info, ifcond, arg_type, boxed):
 181         with ifcontext(ifcond, self._genh, self._genc):
 182             self._genh.add(gen_event_send_decl(name, arg_type, boxed))
 183             self._genc.add(gen_event_send(name, arg_type, boxed,
 184                                           self._event_enum_name,
 185                                           self._event_emit_name))
 186         self._event_enum_members.append(QAPISchemaMember(name, ifcond))
 187
 188
 189 def gen_events(schema, output_dir, prefix):
 190     vis = QAPISchemaGenEventVisitor(prefix)
 191     schema.visit(vis)
 192     vis.write(output_dir)