scripts/qapi-visit.py

   1 #
   2 # QAPI visitor generator
   3 #
   4 # Copyright IBM, Corp. 2011
   5 # Copyright (C) 2014-2015 Red Hat, Inc.
   6 #
   7 # Authors:
   8 #  Anthony Liguori <aliguori@us.ibm.com>
   9 #  Michael Roth    <mdroth@linux.vnet.ibm.com>
  10 #  Markus Armbruster <armbru@redhat.com>
  11 #
  12 # This work is licensed under the terms of the GNU GPL, version 2.
  13 # See the COPYING file in the top-level directory.
  14
  15 from qapi import *
  16 import re
  17
  18 # visit_type_FOO_implicit() is emitted as needed; track if it has already
  19 # been output.
  20 implicit_structs_seen = set()
  21
  22 # visit_type_FOO_fields() is always emitted; track if a forward declaration
  23 # or implementation has already been output.
  24 struct_fields_seen = set()
  25
  26
  27 def gen_visit_decl(name, scalar=False):
  28     c_type = c_name(name) + ' *'
  29     if not scalar:
  30         c_type += '*'
  31     return mcgen('''
  32 void visit_type_%(c_name)s(Visitor *v, %(c_type)sobj, const char *name, Error **errp);
  33 ''',
  34                  c_name=c_name(name), c_type=c_type)
  35
  36
  37 def gen_visit_fields_decl(typ):
  38     ret = ''
  39     if typ.name not in struct_fields_seen:
  40         ret += mcgen('''
  41
  42 static void visit_type_%(c_type)s_fields(Visitor *v, %(c_type)s **obj, Error **errp);
  43 ''',
  44                      c_type=typ.c_name())
  45         struct_fields_seen.add(typ.name)
  46     return ret
  47
  48
  49 def gen_visit_implicit_struct(typ):
  50     if typ in implicit_structs_seen:
  51         return ''
  52     implicit_structs_seen.add(typ)
  53
  54     ret = gen_visit_fields_decl(typ)
  55
  56     ret += mcgen('''
  57
  58 static void visit_type_implicit_%(c_type)s(Visitor *v, %(c_type)s **obj, Error **errp)
  59 {
  60     Error *err = NULL;
  61
  62     visit_start_implicit_struct(v, (void **)obj, sizeof(%(c_type)s), &err);
  63     if (!err) {
  64         visit_type_%(c_type)s_fields(v, obj, errp);
  65         visit_end_implicit_struct(v, &err);
  66     }
  67     error_propagate(errp, err);
  68 }
  69 ''',
  70                  c_type=typ.c_name())
  71     return ret
  72
  73
  74 def gen_visit_struct_fields(name, base, members):
  75     ret = ''
  76
  77     if base:
  78         ret += gen_visit_fields_decl(base)
  79
  80     struct_fields_seen.add(name)
  81     ret += mcgen('''
  82
  83 static void visit_type_%(c_name)s_fields(Visitor *v, %(c_name)s **obj, Error **errp)
  84 {
  85     Error *err = NULL;
  86
  87 ''',
  88                  c_name=c_name(name))
  89
  90     if base:
  91         ret += mcgen('''
  92     visit_type_%(c_type)s_fields(v, (%(c_type)s **)obj, &err);
  93 ''',
  94                      c_type=base.c_name())
  95         ret += gen_err_check()
  96
  97     ret += gen_visit_fields(members, prefix='(*obj)->')
  98
  99     # 'goto out' produced for base, and by gen_visit_fields() for each member
 100     if base or members:
 101         ret += mcgen('''
 102
 103 out:
 104 ''')
 105     ret += mcgen('''
 106     error_propagate(errp, err);
 107 }
 108 ''')
 109     return ret
 110
 111
 112 def gen_visit_struct(name, base, members):
 113     ret = gen_visit_struct_fields(name, base, members)
 114
 115     # FIXME: if *obj is NULL on entry, and visit_start_struct() assigns to
 116     # *obj, but then visit_type_FOO_fields() fails, we should clean up *obj
 117     # rather than leaving it non-NULL. As currently written, the caller must
 118     # call qapi_free_FOO() to avoid a memory leak of the partial FOO.
 119     ret += mcgen('''
 120
 121 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 122 {
 123     Error *err = NULL;
 124
 125     visit_start_struct(v, (void **)obj, "%(name)s", name, sizeof(%(c_name)s), &err);
 126     if (!err) {
 127         if (*obj) {
 128             visit_type_%(c_name)s_fields(v, obj, errp);
 129         }
 130         visit_end_struct(v, &err);
 131     }
 132     error_propagate(errp, err);
 133 }
 134 ''',
 135                  name=name, c_name=c_name(name))
 136
 137     return ret
 138
 139
 140 def gen_visit_list(name, element_type):
 141     # FIXME: if *obj is NULL on entry, and the first visit_next_list()
 142     # assigns to *obj, while a later one fails, we should clean up *obj
 143     # rather than leaving it non-NULL. As currently written, the caller must
 144     # call qapi_free_FOOList() to avoid a memory leak of the partial FOOList.
 145     return mcgen('''
 146
 147 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 148 {
 149     Error *err = NULL;
 150     GenericList *i, **prev;
 151
 152     visit_start_list(v, name, &err);
 153     if (err) {
 154         goto out;
 155     }
 156
 157     for (prev = (GenericList **)obj;
 158          !err && (i = visit_next_list(v, prev, &err)) != NULL;
 159          prev = &i) {
 160         %(c_name)s *native_i = (%(c_name)s *)i;
 161         visit_type_%(c_elt_type)s(v, &native_i->value, NULL, &err);
 162     }
 163
 164     error_propagate(errp, err);
 165     err = NULL;
 166     visit_end_list(v, &err);
 167 out:
 168     error_propagate(errp, err);
 169 }
 170 ''',
 171                  c_name=c_name(name), c_elt_type=element_type.c_name())
 172
 173
 174 def gen_visit_enum(name):
 175     # FIXME cast from enum *obj to int * invalidly assumes enum is int
 176     return mcgen('''
 177
 178 void visit_type_%(c_name)s(Visitor *v, %(c_name)s *obj, const char *name, Error **errp)
 179 {
 180     visit_type_enum(v, (int *)obj, %(c_name)s_lookup, "%(name)s", name, errp);
 181 }
 182 ''',
 183                  c_name=c_name(name), name=name)
 184
 185
 186 def gen_visit_alternate(name, variants):
 187     promote_int = 'true'
 188     for var in variants.variants:
 189         if var.type.alternate_qtype() == 'QTYPE_QINT':
 190             promote_int = 'false'
 191
 192     ret = mcgen('''
 193
 194 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 195 {
 196     Error *err = NULL;
 197
 198     visit_start_implicit_struct(v, (void**) obj, sizeof(%(c_name)s), &err);
 199     if (err) {
 200         goto out;
 201     }
 202     visit_get_next_type(v, &(*obj)->type, %(promote_int)s, name, &err);
 203     if (err) {
 204         goto out_obj;
 205     }
 206     switch ((*obj)->type) {
 207 ''',
 208                 c_name=c_name(name), promote_int=promote_int)
 209
 210     for var in variants.variants:
 211         ret += mcgen('''
 212     case %(case)s:
 213         visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, name, &err);
 214         break;
 215 ''',
 216                      case=var.type.alternate_qtype(),
 217                      c_type=var.type.c_name(),
 218                      c_name=c_name(var.name))
 219
 220     ret += mcgen('''
 221     default:
 222         error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 223                    "%(name)s");
 224     }
 225 out_obj:
 226     error_propagate(errp, err);
 227     err = NULL;
 228     visit_end_implicit_struct(v, &err);
 229 out:
 230     error_propagate(errp, err);
 231 }
 232 ''',
 233                  name=name)
 234
 235     return ret
 236
 237
 238 def gen_visit_union(name, base, variants):
 239     ret = ''
 240
 241     if base:
 242         ret += gen_visit_fields_decl(base)
 243
 244     for var in variants.variants:
 245         # Ugly special case for simple union TODO get rid of it
 246         if not var.simple_union_type():
 247             ret += gen_visit_implicit_struct(var.type)
 248
 249     ret += mcgen('''
 250
 251 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 252 {
 253     Error *err = NULL;
 254
 255     visit_start_struct(v, (void **)obj, "%(name)s", name, sizeof(%(c_name)s), &err);
 256     if (err) {
 257         goto out;
 258     }
 259     if (!*obj) {
 260         goto out_obj;
 261     }
 262 ''',
 263                  c_name=c_name(name), name=name)
 264
 265     if base:
 266         ret += mcgen('''
 267     visit_type_%(c_name)s_fields(v, (%(c_name)s **)obj, &err);
 268 ''',
 269                      c_name=base.c_name())
 270     else:
 271         ret += mcgen('''
 272     visit_type_%(c_type)s(v, &(*obj)->%(c_name)s, "%(name)s", &err);
 273 ''',
 274                      c_type=variants.tag_member.type.c_name(),
 275                      c_name=c_name(variants.tag_member.name),
 276                      name=variants.tag_member.name)
 277     ret += gen_err_check(label='out_obj')
 278     ret += mcgen('''
 279     if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) {
 280         goto out_obj;
 281     }
 282     switch ((*obj)->%(c_name)s) {
 283 ''',
 284                  c_name=c_name(variants.tag_member.name))
 285
 286     for var in variants.variants:
 287         # TODO ugly special case for simple union
 288         simple_union_type = var.simple_union_type()
 289         ret += mcgen('''
 290     case %(case)s:
 291 ''',
 292                      case=c_enum_const(variants.tag_member.type.name,
 293                                        var.name))
 294         if simple_union_type:
 295             ret += mcgen('''
 296         visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, "data", &err);
 297 ''',
 298                          c_type=simple_union_type.c_name(),
 299                          c_name=c_name(var.name))
 300         else:
 301             ret += mcgen('''
 302         visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err);
 303 ''',
 304                          c_type=var.type.c_name(),
 305                          c_name=c_name(var.name))
 306         ret += mcgen('''
 307         break;
 308 ''')
 309
 310     ret += mcgen('''
 311     default:
 312         abort();
 313     }
 314 out_obj:
 315     error_propagate(errp, err);
 316     err = NULL;
 317     if (*obj) {
 318         visit_end_union(v, !!(*obj)->u.data, &err);
 319     }
 320     error_propagate(errp, err);
 321     err = NULL;
 322     visit_end_struct(v, &err);
 323 out:
 324     error_propagate(errp, err);
 325 }
 326 ''')
 327
 328     return ret
 329
 330
 331 class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
 332     def __init__(self):
 333         self.decl = None
 334         self.defn = None
 335         self._btin = None
 336
 337     def visit_begin(self, schema):
 338         self.decl = ''
 339         self.defn = ''
 340         self._btin = guardstart('QAPI_VISIT_BUILTIN')
 341
 342     def visit_end(self):
 343         # To avoid header dependency hell, we always generate
 344         # declarations for built-in types in our header files and
 345         # simply guard them.  See also do_builtins (command line
 346         # option -b).
 347         self._btin += guardend('QAPI_VISIT_BUILTIN')
 348         self.decl = self._btin + self.decl
 349         self._btin = None
 350
 351     def visit_needed(self, entity):
 352         # Visit everything except implicit objects
 353         return not (entity.is_implicit() and
 354                     isinstance(entity, QAPISchemaObjectType))
 355
 356     def visit_enum_type(self, name, info, values, prefix):
 357         # Special case for our lone builtin enum type
 358         # TODO use something cleaner than existence of info
 359         if not info:
 360             self._btin += gen_visit_decl(name, scalar=True)
 361             if do_builtins:
 362                 self.defn += gen_visit_enum(name)
 363         else:
 364             self.decl += gen_visit_decl(name, scalar=True)
 365             self.defn += gen_visit_enum(name)
 366
 367     def visit_array_type(self, name, info, element_type):
 368         decl = gen_visit_decl(name)
 369         defn = gen_visit_list(name, element_type)
 370         if isinstance(element_type, QAPISchemaBuiltinType):
 371             self._btin += decl
 372             if do_builtins:
 373                 self.defn += defn
 374         else:
 375             self.decl += decl
 376             self.defn += defn
 377
 378     def visit_object_type(self, name, info, base, members, variants):
 379         self.decl += gen_visit_decl(name)
 380         if variants:
 381             if members:
 382                 # Members other than variants.tag_member not implemented
 383                 assert len(members) == 1
 384                 assert members[0] == variants.tag_member
 385             self.defn += gen_visit_union(name, base, variants)
 386         else:
 387             self.defn += gen_visit_struct(name, base, members)
 388
 389     def visit_alternate_type(self, name, info, variants):
 390         self.decl += gen_visit_decl(name)
 391         self.defn += gen_visit_alternate(name, variants)
 392
 393 # If you link code generated from multiple schemata, you want only one
 394 # instance of the code for built-in types.  Generate it only when
 395 # do_builtins, enabled by command line option -b.  See also
 396 # QAPISchemaGenVisitVisitor.visit_end().
 397 do_builtins = False
 398
 399 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 400     parse_command_line("b", ["builtins"])
 401
 402 for o, a in opts:
 403     if o in ("-b", "--builtins"):
 404         do_builtins = True
 405
 406 c_comment = '''
 407 /*
 408  * schema-defined QAPI visitor functions
 409  *
 410  * Copyright IBM, Corp. 2011
 411  *
 412  * Authors:
 413  *  Anthony Liguori   <aliguori@us.ibm.com>
 414  *
 415  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 416  * See the COPYING.LIB file in the top-level directory.
 417  *
 418  */
 419 '''
 420 h_comment = '''
 421 /*
 422  * schema-defined QAPI visitor functions
 423  *
 424  * Copyright IBM, Corp. 2011
 425  *
 426  * Authors:
 427  *  Anthony Liguori   <aliguori@us.ibm.com>
 428  *
 429  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 430  * See the COPYING.LIB file in the top-level directory.
 431  *
 432  */
 433 '''
 434
 435 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 436                             'qapi-visit.c', 'qapi-visit.h',
 437                             c_comment, h_comment)
 438
 439 fdef.write(mcgen('''
 440 #include "qemu-common.h"
 441 #include "%(prefix)sqapi-visit.h"
 442 ''',
 443                  prefix=prefix))
 444
 445 fdecl.write(mcgen('''
 446 #include "qapi/visitor.h"
 447 #include "qapi/qmp/qerror.h"
 448 #include "%(prefix)sqapi-types.h"
 449
 450 ''',
 451                   prefix=prefix))
 452
 453 schema = QAPISchema(input_file)
 454 gen = QAPISchemaGenVisitVisitor()
 455 schema.visit(gen)
 456 fdef.write(gen.defn)
 457 fdecl.write(gen.decl)
 458
 459 close_output(fdef, fdecl)