scripts/qapi-visit.py

   1 #
   2 # QAPI visitor generator
   3 #
   4 # Copyright IBM, Corp. 2011
   5 # Copyright (C) 2014-2016 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         goto out;
 128     }
 129     if (!*obj) {
 130         goto out_obj;
 131     }
 132     visit_type_%(c_name)s_fields(v, obj, &err);
 133     error_propagate(errp, err);
 134     err = NULL;
 135 out_obj:
 136     visit_end_struct(v, &err);
 137 out:
 138     error_propagate(errp, err);
 139 }
 140 ''',
 141                  name=name, c_name=c_name(name))
 142
 143     return ret
 144
 145
 146 def gen_visit_list(name, element_type):
 147     # FIXME: if *obj is NULL on entry, and the first visit_next_list()
 148     # assigns to *obj, while a later one fails, we should clean up *obj
 149     # rather than leaving it non-NULL. As currently written, the caller must
 150     # call qapi_free_FOOList() to avoid a memory leak of the partial FOOList.
 151     return mcgen('''
 152
 153 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 154 {
 155     Error *err = NULL;
 156     GenericList *i, **prev;
 157
 158     visit_start_list(v, name, &err);
 159     if (err) {
 160         goto out;
 161     }
 162
 163     for (prev = (GenericList **)obj;
 164          !err && (i = visit_next_list(v, prev, &err)) != NULL;
 165          prev = &i) {
 166         %(c_name)s *native_i = (%(c_name)s *)i;
 167         visit_type_%(c_elt_type)s(v, &native_i->value, NULL, &err);
 168     }
 169
 170     error_propagate(errp, err);
 171     err = NULL;
 172     visit_end_list(v, &err);
 173 out:
 174     error_propagate(errp, err);
 175 }
 176 ''',
 177                  c_name=c_name(name), c_elt_type=element_type.c_name())
 178
 179
 180 def gen_visit_enum(name):
 181     return mcgen('''
 182
 183 void visit_type_%(c_name)s(Visitor *v, %(c_name)s *obj, const char *name, Error **errp)
 184 {
 185     int value = *obj;
 186     visit_type_enum(v, &value, %(c_name)s_lookup, "%(name)s", name, errp);
 187     *obj = value;
 188 }
 189 ''',
 190                  c_name=c_name(name), name=name)
 191
 192
 193 def gen_visit_alternate(name, variants):
 194     promote_int = 'true'
 195     for var in variants.variants:
 196         if var.type.alternate_qtype() == 'QTYPE_QINT':
 197             promote_int = 'false'
 198
 199     ret = mcgen('''
 200
 201 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 202 {
 203     Error *err = NULL;
 204
 205     visit_start_implicit_struct(v, (void**) obj, sizeof(%(c_name)s), &err);
 206     if (err) {
 207         goto out;
 208     }
 209     visit_get_next_type(v, &(*obj)->type, %(promote_int)s, name, &err);
 210     if (err) {
 211         goto out_obj;
 212     }
 213     switch ((*obj)->type) {
 214 ''',
 215                 c_name=c_name(name), promote_int=promote_int)
 216
 217     for var in variants.variants:
 218         ret += mcgen('''
 219     case %(case)s:
 220         visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, name, &err);
 221         break;
 222 ''',
 223                      case=var.type.alternate_qtype(),
 224                      c_type=var.type.c_name(),
 225                      c_name=c_name(var.name))
 226
 227     ret += mcgen('''
 228     default:
 229         error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 230                    "%(name)s");
 231     }
 232 out_obj:
 233     error_propagate(errp, err);
 234     err = NULL;
 235     visit_end_implicit_struct(v, &err);
 236 out:
 237     error_propagate(errp, err);
 238 }
 239 ''',
 240                  name=name)
 241
 242     return ret
 243
 244
 245 def gen_visit_union(name, base, variants):
 246     ret = ''
 247
 248     if base:
 249         ret += gen_visit_fields_decl(base)
 250
 251     for var in variants.variants:
 252         # Ugly special case for simple union TODO get rid of it
 253         if not var.simple_union_type():
 254             ret += gen_visit_implicit_struct(var.type)
 255
 256     ret += mcgen('''
 257
 258 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 259 {
 260     Error *err = NULL;
 261
 262     visit_start_struct(v, (void **)obj, "%(name)s", name, sizeof(%(c_name)s), &err);
 263     if (err) {
 264         goto out;
 265     }
 266     if (!*obj) {
 267         goto out_obj;
 268     }
 269 ''',
 270                  c_name=c_name(name), name=name)
 271
 272     if base:
 273         ret += mcgen('''
 274     visit_type_%(c_name)s_fields(v, (%(c_name)s **)obj, &err);
 275 ''',
 276                      c_name=base.c_name())
 277     else:
 278         ret += mcgen('''
 279     visit_type_%(c_type)s(v, &(*obj)->%(c_name)s, "%(name)s", &err);
 280 ''',
 281                      c_type=variants.tag_member.type.c_name(),
 282                      c_name=c_name(variants.tag_member.name),
 283                      name=variants.tag_member.name)
 284     ret += gen_err_check(label='out_obj')
 285     ret += mcgen('''
 286     if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) {
 287         goto out_obj;
 288     }
 289     switch ((*obj)->%(c_name)s) {
 290 ''',
 291                  c_name=c_name(variants.tag_member.name))
 292
 293     for var in variants.variants:
 294         # TODO ugly special case for simple union
 295         simple_union_type = var.simple_union_type()
 296         ret += mcgen('''
 297     case %(case)s:
 298 ''',
 299                      case=c_enum_const(variants.tag_member.type.name,
 300                                        var.name))
 301         if simple_union_type:
 302             ret += mcgen('''
 303         visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, "data", &err);
 304 ''',
 305                          c_type=simple_union_type.c_name(),
 306                          c_name=c_name(var.name))
 307         else:
 308             ret += mcgen('''
 309         visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err);
 310 ''',
 311                          c_type=var.type.c_name(),
 312                          c_name=c_name(var.name))
 313         ret += mcgen('''
 314         break;
 315 ''')
 316
 317     ret += mcgen('''
 318     default:
 319         abort();
 320     }
 321 out_obj:
 322     error_propagate(errp, err);
 323     err = NULL;
 324     visit_end_struct(v, &err);
 325 out:
 326     error_propagate(errp, err);
 327 }
 328 ''')
 329
 330     return ret
 331
 332
 333 class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
 334     def __init__(self):
 335         self.decl = None
 336         self.defn = None
 337         self._btin = None
 338
 339     def visit_begin(self, schema):
 340         self.decl = ''
 341         self.defn = ''
 342         self._btin = guardstart('QAPI_VISIT_BUILTIN')
 343
 344     def visit_end(self):
 345         # To avoid header dependency hell, we always generate
 346         # declarations for built-in types in our header files and
 347         # simply guard them.  See also do_builtins (command line
 348         # option -b).
 349         self._btin += guardend('QAPI_VISIT_BUILTIN')
 350         self.decl = self._btin + self.decl
 351         self._btin = None
 352
 353     def visit_needed(self, entity):
 354         # Visit everything except implicit objects
 355         return not (entity.is_implicit() and
 356                     isinstance(entity, QAPISchemaObjectType))
 357
 358     def visit_enum_type(self, name, info, values, prefix):
 359         # Special case for our lone builtin enum type
 360         # TODO use something cleaner than existence of info
 361         if not info:
 362             self._btin += gen_visit_decl(name, scalar=True)
 363             if do_builtins:
 364                 self.defn += gen_visit_enum(name)
 365         else:
 366             self.decl += gen_visit_decl(name, scalar=True)
 367             self.defn += gen_visit_enum(name)
 368
 369     def visit_array_type(self, name, info, element_type):
 370         decl = gen_visit_decl(name)
 371         defn = gen_visit_list(name, element_type)
 372         if isinstance(element_type, QAPISchemaBuiltinType):
 373             self._btin += decl
 374             if do_builtins:
 375                 self.defn += defn
 376         else:
 377             self.decl += decl
 378             self.defn += defn
 379
 380     def visit_object_type(self, name, info, base, members, variants):
 381         self.decl += gen_visit_decl(name)
 382         if variants:
 383             if members:
 384                 # Members other than variants.tag_member not implemented
 385                 assert len(members) == 1
 386                 assert members[0] == variants.tag_member
 387             self.defn += gen_visit_union(name, base, variants)
 388         else:
 389             self.defn += gen_visit_struct(name, base, members)
 390
 391     def visit_alternate_type(self, name, info, variants):
 392         self.decl += gen_visit_decl(name)
 393         self.defn += gen_visit_alternate(name, variants)
 394
 395 # If you link code generated from multiple schemata, you want only one
 396 # instance of the code for built-in types.  Generate it only when
 397 # do_builtins, enabled by command line option -b.  See also
 398 # QAPISchemaGenVisitVisitor.visit_end().
 399 do_builtins = False
 400
 401 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 402     parse_command_line("b", ["builtins"])
 403
 404 for o, a in opts:
 405     if o in ("-b", "--builtins"):
 406         do_builtins = True
 407
 408 c_comment = '''
 409 /*
 410  * schema-defined QAPI visitor functions
 411  *
 412  * Copyright IBM, Corp. 2011
 413  *
 414  * Authors:
 415  *  Anthony Liguori   <aliguori@us.ibm.com>
 416  *
 417  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 418  * See the COPYING.LIB file in the top-level directory.
 419  *
 420  */
 421 '''
 422 h_comment = '''
 423 /*
 424  * schema-defined QAPI visitor functions
 425  *
 426  * Copyright IBM, Corp. 2011
 427  *
 428  * Authors:
 429  *  Anthony Liguori   <aliguori@us.ibm.com>
 430  *
 431  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 432  * See the COPYING.LIB file in the top-level directory.
 433  *
 434  */
 435 '''
 436
 437 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 438                             'qapi-visit.c', 'qapi-visit.h',
 439                             c_comment, h_comment)
 440
 441 fdef.write(mcgen('''
 442 #include "qemu-common.h"
 443 #include "%(prefix)sqapi-visit.h"
 444 ''',
 445                  prefix=prefix))
 446
 447 fdecl.write(mcgen('''
 448 #include "qapi/visitor.h"
 449 #include "qapi/qmp/qerror.h"
 450 #include "%(prefix)sqapi-types.h"
 451
 452 ''',
 453                   prefix=prefix))
 454
 455 schema = QAPISchema(input_file)
 456 gen = QAPISchemaGenVisitVisitor()
 457 schema.visit(gen)
 458 fdef.write(gen.defn)
 459 fdecl.write(gen.decl)
 460
 461 close_output(fdef, fdecl)