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     # FIXME cast from enum *obj to int * invalidly assumes enum is int
 182     return mcgen('''
 183
 184 void visit_type_%(c_name)s(Visitor *v, %(c_name)s *obj, const char *name, Error **errp)
 185 {
 186     visit_type_enum(v, (int *)obj, %(c_name)s_lookup, "%(name)s", name, errp);
 187 }
 188 ''',
 189                  c_name=c_name(name), name=name)
 190
 191
 192 def gen_visit_alternate(name, variants):
 193     promote_int = 'true'
 194     for var in variants.variants:
 195         if var.type.alternate_qtype() == 'QTYPE_QINT':
 196             promote_int = 'false'
 197
 198     ret = mcgen('''
 199
 200 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 201 {
 202     Error *err = NULL;
 203
 204     visit_start_implicit_struct(v, (void**) obj, sizeof(%(c_name)s), &err);
 205     if (err) {
 206         goto out;
 207     }
 208     visit_get_next_type(v, &(*obj)->type, %(promote_int)s, name, &err);
 209     if (err) {
 210         goto out_obj;
 211     }
 212     switch ((*obj)->type) {
 213 ''',
 214                 c_name=c_name(name), promote_int=promote_int)
 215
 216     for var in variants.variants:
 217         ret += mcgen('''
 218     case %(case)s:
 219         visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, name, &err);
 220         break;
 221 ''',
 222                      case=var.type.alternate_qtype(),
 223                      c_type=var.type.c_name(),
 224                      c_name=c_name(var.name))
 225
 226     ret += mcgen('''
 227     default:
 228         error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 229                    "%(name)s");
 230     }
 231 out_obj:
 232     error_propagate(errp, err);
 233     err = NULL;
 234     visit_end_implicit_struct(v, &err);
 235 out:
 236     error_propagate(errp, err);
 237 }
 238 ''',
 239                  name=name)
 240
 241     return ret
 242
 243
 244 def gen_visit_union(name, base, variants):
 245     ret = ''
 246
 247     if base:
 248         ret += gen_visit_fields_decl(base)
 249
 250     for var in variants.variants:
 251         # Ugly special case for simple union TODO get rid of it
 252         if not var.simple_union_type():
 253             ret += gen_visit_implicit_struct(var.type)
 254
 255     ret += mcgen('''
 256
 257 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 258 {
 259     Error *err = NULL;
 260
 261     visit_start_struct(v, (void **)obj, "%(name)s", name, sizeof(%(c_name)s), &err);
 262     if (err) {
 263         goto out;
 264     }
 265     if (!*obj) {
 266         goto out_obj;
 267     }
 268 ''',
 269                  c_name=c_name(name), name=name)
 270
 271     if base:
 272         ret += mcgen('''
 273     visit_type_%(c_name)s_fields(v, (%(c_name)s **)obj, &err);
 274 ''',
 275                      c_name=base.c_name())
 276     else:
 277         ret += mcgen('''
 278     visit_type_%(c_type)s(v, &(*obj)->%(c_name)s, "%(name)s", &err);
 279 ''',
 280                      c_type=variants.tag_member.type.c_name(),
 281                      c_name=c_name(variants.tag_member.name),
 282                      name=variants.tag_member.name)
 283     ret += gen_err_check(label='out_obj')
 284     ret += mcgen('''
 285     if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) {
 286         goto out_obj;
 287     }
 288     switch ((*obj)->%(c_name)s) {
 289 ''',
 290                  c_name=c_name(variants.tag_member.name))
 291
 292     for var in variants.variants:
 293         # TODO ugly special case for simple union
 294         simple_union_type = var.simple_union_type()
 295         ret += mcgen('''
 296     case %(case)s:
 297 ''',
 298                      case=c_enum_const(variants.tag_member.type.name,
 299                                        var.name))
 300         if simple_union_type:
 301             ret += mcgen('''
 302         visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, "data", &err);
 303 ''',
 304                          c_type=simple_union_type.c_name(),
 305                          c_name=c_name(var.name))
 306         else:
 307             ret += mcgen('''
 308         visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err);
 309 ''',
 310                          c_type=var.type.c_name(),
 311                          c_name=c_name(var.name))
 312         ret += mcgen('''
 313         break;
 314 ''')
 315
 316     ret += mcgen('''
 317     default:
 318         abort();
 319     }
 320 out_obj:
 321     error_propagate(errp, err);
 322     err = NULL;
 323     if (*obj) {
 324         visit_end_union(v, !!(*obj)->u.data, &err);
 325     }
 326     error_propagate(errp, err);
 327     err = NULL;
 328     visit_end_struct(v, &err);
 329 out:
 330     error_propagate(errp, err);
 331 }
 332 ''')
 333
 334     return ret
 335
 336
 337 class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
 338     def __init__(self):
 339         self.decl = None
 340         self.defn = None
 341         self._btin = None
 342
 343     def visit_begin(self, schema):
 344         self.decl = ''
 345         self.defn = ''
 346         self._btin = guardstart('QAPI_VISIT_BUILTIN')
 347
 348     def visit_end(self):
 349         # To avoid header dependency hell, we always generate
 350         # declarations for built-in types in our header files and
 351         # simply guard them.  See also do_builtins (command line
 352         # option -b).
 353         self._btin += guardend('QAPI_VISIT_BUILTIN')
 354         self.decl = self._btin + self.decl
 355         self._btin = None
 356
 357     def visit_needed(self, entity):
 358         # Visit everything except implicit objects
 359         return not (entity.is_implicit() and
 360                     isinstance(entity, QAPISchemaObjectType))
 361
 362     def visit_enum_type(self, name, info, values, prefix):
 363         # Special case for our lone builtin enum type
 364         # TODO use something cleaner than existence of info
 365         if not info:
 366             self._btin += gen_visit_decl(name, scalar=True)
 367             if do_builtins:
 368                 self.defn += gen_visit_enum(name)
 369         else:
 370             self.decl += gen_visit_decl(name, scalar=True)
 371             self.defn += gen_visit_enum(name)
 372
 373     def visit_array_type(self, name, info, element_type):
 374         decl = gen_visit_decl(name)
 375         defn = gen_visit_list(name, element_type)
 376         if isinstance(element_type, QAPISchemaBuiltinType):
 377             self._btin += decl
 378             if do_builtins:
 379                 self.defn += defn
 380         else:
 381             self.decl += decl
 382             self.defn += defn
 383
 384     def visit_object_type(self, name, info, base, members, variants):
 385         self.decl += gen_visit_decl(name)
 386         if variants:
 387             if members:
 388                 # Members other than variants.tag_member not implemented
 389                 assert len(members) == 1
 390                 assert members[0] == variants.tag_member
 391             self.defn += gen_visit_union(name, base, variants)
 392         else:
 393             self.defn += gen_visit_struct(name, base, members)
 394
 395     def visit_alternate_type(self, name, info, variants):
 396         self.decl += gen_visit_decl(name)
 397         self.defn += gen_visit_alternate(name, variants)
 398
 399 # If you link code generated from multiple schemata, you want only one
 400 # instance of the code for built-in types.  Generate it only when
 401 # do_builtins, enabled by command line option -b.  See also
 402 # QAPISchemaGenVisitVisitor.visit_end().
 403 do_builtins = False
 404
 405 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 406     parse_command_line("b", ["builtins"])
 407
 408 for o, a in opts:
 409     if o in ("-b", "--builtins"):
 410         do_builtins = True
 411
 412 c_comment = '''
 413 /*
 414  * schema-defined QAPI visitor functions
 415  *
 416  * Copyright IBM, Corp. 2011
 417  *
 418  * Authors:
 419  *  Anthony Liguori   <aliguori@us.ibm.com>
 420  *
 421  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 422  * See the COPYING.LIB file in the top-level directory.
 423  *
 424  */
 425 '''
 426 h_comment = '''
 427 /*
 428  * schema-defined QAPI visitor functions
 429  *
 430  * Copyright IBM, Corp. 2011
 431  *
 432  * Authors:
 433  *  Anthony Liguori   <aliguori@us.ibm.com>
 434  *
 435  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 436  * See the COPYING.LIB file in the top-level directory.
 437  *
 438  */
 439 '''
 440
 441 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 442                             'qapi-visit.c', 'qapi-visit.h',
 443                             c_comment, h_comment)
 444
 445 fdef.write(mcgen('''
 446 #include "qemu-common.h"
 447 #include "%(prefix)sqapi-visit.h"
 448 ''',
 449                  prefix=prefix))
 450
 451 fdecl.write(mcgen('''
 452 #include "qapi/visitor.h"
 453 #include "qapi/qmp/qerror.h"
 454 #include "%(prefix)sqapi-types.h"
 455
 456 ''',
 457                   prefix=prefix))
 458
 459 schema = QAPISchema(input_file)
 460 gen = QAPISchemaGenVisitVisitor()
 461 schema.visit(gen)
 462 fdef.write(gen.defn)
 463 fdecl.write(gen.decl)
 464
 465 close_output(fdef, fdecl)