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, 'Error **errp')}
  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):
  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     Error *err = NULL;
  74     QMPEventFuncEmit emit;
  75 ''',
  76                 proto=build_event_send_proto(name, arg_type, boxed))
  77
  78     if arg_type and not arg_type.is_empty():
  79         ret += mcgen('''
  80     QObject *obj;
  81     Visitor *v;
  82 ''')
  83         if not boxed:
  84             ret += gen_param_var(arg_type)
  85     else:
  86         assert not boxed
  87
  88     ret += mcgen('''
  89
  90     emit = qmp_event_get_func_emit();
  91     if (!emit) {
  92         return;
  93     }
  94
  95     qmp = qmp_event_build_dict("%(name)s");
  96
  97 ''',
  98                  name=name)
  99
 100     if arg_type and not arg_type.is_empty():
 101         ret += mcgen('''
 102     v = qobject_output_visitor_new(&obj);
 103 ''')
 104         if not arg_type.is_implicit():
 105             ret += mcgen('''
 106     visit_type_%(c_name)s(v, "%(name)s", &arg, &err);
 107 ''',
 108                          name=name, c_name=arg_type.c_name())
 109         else:
 110             ret += mcgen('''
 111
 112     visit_start_struct(v, "%(name)s", NULL, 0, &err);
 113     if (err) {
 114         goto out;
 115     }
 116     visit_type_%(c_name)s_members(v, &param, &err);
 117     if (!err) {
 118         visit_check_struct(v, &err);
 119     }
 120     visit_end_struct(v, NULL);
 121 ''',
 122                          name=name, c_name=arg_type.c_name())
 123         ret += mcgen('''
 124     if (err) {
 125         goto out;
 126     }
 127
 128     visit_complete(v, &obj);
 129     qdict_put_obj(qmp, "data", obj);
 130 ''')
 131
 132     ret += mcgen('''
 133     emit(%(c_enum)s, qmp, &err);
 134
 135 ''',
 136                  c_enum=c_enum_const(event_enum_name, name))
 137
 138     if arg_type and not arg_type.is_empty():
 139         ret += mcgen('''
 140 out:
 141     visit_free(v);
 142 ''')
 143     ret += mcgen('''
 144     error_propagate(errp, err);
 145     qobject_unref(qmp);
 146 }
 147 ''')
 148     return ret
 149
 150
 151 class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
 152
 153     def __init__(self, prefix):
 154         QAPISchemaModularCVisitor.__init__(
 155             self, prefix, 'qapi-events',
 156             ' * Schema-defined QAPI/QMP events', __doc__)
 157         self._enum_name = c_name(prefix + 'QAPIEvent', protect=False)
 158         self._event_names = []
 159
 160     def _begin_module(self, name):
 161         types = self._module_basename('qapi-types', name)
 162         visit = self._module_basename('qapi-visit', name)
 163         self._genc.add(mcgen('''
 164 #include "qemu/osdep.h"
 165 #include "qemu-common.h"
 166 #include "%(prefix)sqapi-events.h"
 167 #include "%(visit)s.h"
 168 #include "qapi/error.h"
 169 #include "qapi/qmp/qdict.h"
 170 #include "qapi/qobject-output-visitor.h"
 171 #include "qapi/qmp-event.h"
 172
 173 ''',
 174                              visit=visit, prefix=self._prefix))
 175         self._genh.add(mcgen('''
 176 #include "qapi/util.h"
 177 #include "%(types)s.h"
 178
 179 ''',
 180                              types=types))
 181
 182     def visit_end(self):
 183         self._genh.add(gen_enum(self._enum_name, self._event_names))
 184         self._genc.add(gen_enum_lookup(self._enum_name, self._event_names))
 185
 186     def visit_event(self, name, info, arg_type, boxed):
 187         self._genh.add(gen_event_send_decl(name, arg_type, boxed))
 188         self._genc.add(gen_event_send(name, arg_type, boxed, self._enum_name))
 189         self._event_names.append(name)
 190
 191
 192 def gen_events(schema, output_dir, prefix):
 193     vis = QAPISchemaGenEventVisitor(prefix)
 194     schema.visit(vis)
 195     vis.write(output_dir)