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