scripts/qapi-event.py

   1 #
   2 # QAPI event generator
   3 #
   4 # Copyright (c) 2014 Wenchao Xia
   5 #
   6 # Authors:
   7 #  Wenchao Xia <wenchaoqemu@gmail.com>
   8 #
   9 # This work is licensed under the terms of the GNU GPL, version 2.
  10 # See the COPYING file in the top-level directory.
  11
  12 from ordereddict import OrderedDict
  13 from qapi import *
  14
  15 def _generate_event_api_name(event_name, params):
  16     api_name = "void qapi_event_send_%s(" % c_name(event_name).lower();
  17     l = len(api_name)
  18
  19     if params:
  20         for argname, argentry, optional in parse_args(params):
  21             if optional:
  22                 api_name += "bool has_%s,\n" % c_name(argname)
  23                 api_name += "".ljust(l)
  24
  25             api_name += "%s %s,\n" % (c_type(argentry, is_param=True),
  26                                       c_name(argname))
  27             api_name += "".ljust(l)
  28
  29     api_name += "Error **errp)"
  30     return api_name;
  31
  32
  33 # Following are the core functions that generate C APIs to emit event.
  34
  35 def generate_event_declaration(api_name):
  36     return mcgen('''
  37
  38 %(api_name)s;
  39 ''',
  40                  api_name = api_name)
  41
  42 def generate_event_implement(api_name, event_name, params):
  43     # step 1: declare any variables
  44     ret = mcgen("""
  45
  46 %(api_name)s
  47 {
  48     QDict *qmp;
  49     Error *local_err = NULL;
  50     QMPEventFuncEmit emit;
  51 """,
  52                 api_name = api_name)
  53
  54     if params:
  55         ret += mcgen("""
  56     QmpOutputVisitor *qov;
  57     Visitor *v;
  58     QObject *obj;
  59
  60 """)
  61
  62     # step 2: check emit function, create a dict
  63     ret += mcgen("""
  64     emit = qmp_event_get_func_emit();
  65     if (!emit) {
  66         return;
  67     }
  68
  69     qmp = qmp_event_build_dict("%(event_name)s");
  70
  71 """,
  72                  event_name = event_name)
  73
  74     # step 3: visit the params if params != None
  75     if params:
  76         ret += mcgen("""
  77     qov = qmp_output_visitor_new();
  78     g_assert(qov);
  79
  80     v = qmp_output_get_visitor(qov);
  81     g_assert(v);
  82
  83     /* Fake visit, as if all members are under a structure */
  84     visit_start_struct(v, NULL, "", "%(event_name)s", 0, &local_err);
  85     if (local_err) {
  86         goto clean;
  87     }
  88
  89 """,
  90                 event_name = event_name)
  91
  92         for argname, argentry, optional in parse_args(params):
  93             if optional:
  94                 ret += mcgen("""
  95     if (has_%(var)s) {
  96 """,
  97                              var = c_name(argname))
  98                 push_indent()
  99
 100             if argentry == "str":
 101                 var_type = "(char **)"
 102             else:
 103                 var_type = ""
 104
 105             ret += mcgen("""
 106     visit_type_%(type)s(v, %(var_type)s&%(var)s, "%(name)s", &local_err);
 107     if (local_err) {
 108         goto clean;
 109     }
 110 """,
 111                          var_type = var_type,
 112                          var = c_name(argname),
 113                          type = type_name(argentry),
 114                          name = argname)
 115
 116             if optional:
 117                 pop_indent()
 118                 ret += mcgen("""
 119     }
 120 """)
 121
 122         ret += mcgen("""
 123
 124     visit_end_struct(v, &local_err);
 125     if (local_err) {
 126         goto clean;
 127     }
 128
 129     obj = qmp_output_get_qobject(qov);
 130     g_assert(obj != NULL);
 131
 132     qdict_put_obj(qmp, "data", obj);
 133 """)
 134
 135     # step 4: call qmp event api
 136     ret += mcgen("""
 137     emit(%(event_enum_value)s, qmp, &local_err);
 138
 139 """,
 140                  event_enum_value = event_enum_value)
 141
 142     # step 5: clean up
 143     if params:
 144         ret += mcgen("""
 145  clean:
 146     qmp_output_visitor_cleanup(qov);
 147 """)
 148     ret += mcgen("""
 149     error_propagate(errp, local_err);
 150     QDECREF(qmp);
 151 }
 152 """)
 153
 154     return ret
 155
 156
 157 # Following are the functions that generate an enum type for all defined
 158 # events, similar to qapi-types.py. Here we already have enum name and
 159 # values which were generated before and recorded in event_enum_*. It also
 160 # works around the issue that "import qapi-types" can't work.
 161
 162 def generate_event_enum_decl(event_enum_name, event_enum_values):
 163     lookup_decl = mcgen('''
 164
 165 extern const char *%(event_enum_name)s_lookup[];
 166 ''',
 167                         event_enum_name = event_enum_name)
 168
 169     enum_decl = mcgen('''
 170 typedef enum %(event_enum_name)s
 171 {
 172 ''',
 173                       event_enum_name = event_enum_name)
 174
 175     # append automatically generated _MAX value
 176     enum_max_value = c_enum_const(event_enum_name, "MAX")
 177     enum_values = event_enum_values + [ enum_max_value ]
 178
 179     i = 0
 180     for value in enum_values:
 181         enum_decl += mcgen('''
 182     %(value)s = %(i)d,
 183 ''',
 184                      value = value,
 185                      i = i)
 186         i += 1
 187
 188     enum_decl += mcgen('''
 189 } %(event_enum_name)s;
 190 ''',
 191                        event_enum_name = event_enum_name)
 192
 193     return lookup_decl + enum_decl
 194
 195 def generate_event_enum_lookup(event_enum_name, event_enum_strings):
 196     ret = mcgen('''
 197
 198 const char *%(event_enum_name)s_lookup[] = {
 199 ''',
 200                 event_enum_name = event_enum_name)
 201
 202     i = 0
 203     for string in event_enum_strings:
 204         ret += mcgen('''
 205     "%(string)s",
 206 ''',
 207                      string = string)
 208
 209     ret += mcgen('''
 210     NULL,
 211 };
 212 ''')
 213     return ret
 214
 215 (input_file, output_dir, do_c, do_h, prefix, dummy) = parse_command_line()
 216
 217 c_comment = '''
 218 /*
 219  * schema-defined QAPI event functions
 220  *
 221  * Copyright (c) 2014 Wenchao Xia
 222  *
 223  * Authors:
 224  *  Wenchao Xia   <wenchaoqemu@gmail.com>
 225  *
 226  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 227  * See the COPYING.LIB file in the top-level directory.
 228  *
 229  */
 230 '''
 231 h_comment = '''
 232 /*
 233  * schema-defined QAPI event functions
 234  *
 235  * Copyright (c) 2014 Wenchao Xia
 236  *
 237  * Authors:
 238  *  Wenchao Xia  <wenchaoqemu@gmail.com>
 239  *
 240  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 241  * See the COPYING.LIB file in the top-level directory.
 242  *
 243  */
 244 '''
 245
 246 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 247                             'qapi-event.c', 'qapi-event.h',
 248                             c_comment, h_comment)
 249
 250 fdef.write(mcgen('''
 251 #include "qemu-common.h"
 252 #include "%(prefix)sqapi-event.h"
 253 #include "%(prefix)sqapi-visit.h"
 254 #include "qapi/qmp-output-visitor.h"
 255 #include "qapi/qmp-event.h"
 256
 257 ''',
 258                  prefix=prefix))
 259
 260 fdecl.write(mcgen('''
 261 #include "qapi/error.h"
 262 #include "qapi/qmp/qdict.h"
 263 #include "%(prefix)sqapi-types.h"
 264
 265 ''',
 266                   prefix=prefix))
 267
 268 exprs = parse_schema(input_file)
 269
 270 event_enum_name = prefix.upper().replace('-', '_') + "QAPIEvent"
 271 event_enum_values = []
 272 event_enum_strings = []
 273
 274 for expr in exprs:
 275     if expr.has_key('event'):
 276         event_name = expr['event']
 277         params = expr.get('data')
 278         if params and len(params) == 0:
 279             params = None
 280
 281         api_name = _generate_event_api_name(event_name, params)
 282         ret = generate_event_declaration(api_name)
 283         fdecl.write(ret)
 284
 285         # We need an enum value per event
 286         event_enum_value = c_enum_const(event_enum_name, event_name)
 287         ret = generate_event_implement(api_name, event_name, params)
 288         fdef.write(ret)
 289
 290         # Record it, and generate enum later
 291         event_enum_values.append(event_enum_value)
 292         event_enum_strings.append(event_name)
 293
 294 ret = generate_event_enum_decl(event_enum_name, event_enum_values)
 295 fdecl.write(ret)
 296 ret = generate_event_enum_lookup(event_enum_name, event_enum_strings)
 297 fdef.write(ret)
 298
 299 close_output(fdef, fdecl)