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, const char *name, %(c_type)sobj, 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);
  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, const char *name, %(c_name)s **obj, Error **errp)
 122 {
 123     Error *err = NULL;
 124
 125     visit_start_struct(v, name, (void **)obj, 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                  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, const char *name, %(c_name)s **obj, 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)) != NULL;
 165          prev = &i) {
 166         %(c_name)s *native_i = (%(c_name)s *)i;
 167         visit_type_%(c_elt_type)s(v, NULL, &native_i->value, &err);
 168     }
 169
 170     visit_end_list(v);
 171 out:
 172     error_propagate(errp, err);
 173 }
 174 ''',
 175                  c_name=c_name(name), c_elt_type=element_type.c_name())
 176
 177
 178 def gen_visit_enum(name):
 179     return mcgen('''
 180
 181 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
 182 {
 183     int value = *obj;
 184     visit_type_enum(v, name, &value, %(c_name)s_lookup, errp);
 185     *obj = value;
 186 }
 187 ''',
 188                  c_name=c_name(name))
 189
 190
 191 def gen_visit_alternate(name, variants):
 192     promote_int = 'true'
 193     for var in variants.variants:
 194         if var.type.alternate_qtype() == 'QTYPE_QINT':
 195             promote_int = 'false'
 196
 197     ret = mcgen('''
 198
 199 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 200 {
 201     Error *err = NULL;
 202
 203     visit_start_implicit_struct(v, (void**) obj, sizeof(%(c_name)s), &err);
 204     if (err) {
 205         goto out;
 206     }
 207     visit_get_next_type(v, name, &(*obj)->type, %(promote_int)s, &err);
 208     if (err) {
 209         goto out_obj;
 210     }
 211     switch ((*obj)->type) {
 212 ''',
 213                 c_name=c_name(name), promote_int=promote_int)
 214
 215     for var in variants.variants:
 216         ret += mcgen('''
 217     case %(case)s:
 218         visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
 219         break;
 220 ''',
 221                      case=var.type.alternate_qtype(),
 222                      c_type=var.type.c_name(),
 223                      c_name=c_name(var.name))
 224
 225     ret += mcgen('''
 226     default:
 227         error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 228                    "%(name)s");
 229     }
 230 out_obj:
 231     visit_end_implicit_struct(v);
 232 out:
 233     error_propagate(errp, err);
 234 }
 235 ''',
 236                  name=name)
 237
 238     return ret
 239
 240
 241 def gen_visit_union(name, base, members, variants):
 242     ret = gen_visit_struct_fields(name, base, members)
 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, const char *name, %(c_name)s **obj, Error **errp)
 252 {
 253     Error *err = NULL;
 254
 255     visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
 256     if (err) {
 257         goto out;
 258     }
 259     if (!*obj) {
 260         goto out_obj;
 261     }
 262     visit_type_%(c_name)s_fields(v, obj, &err);
 263 ''',
 264                  c_name=c_name(name))
 265     ret += gen_err_check(label='out_obj')
 266     ret += mcgen('''
 267     if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) {
 268         goto out_obj;
 269     }
 270     switch ((*obj)->%(c_name)s) {
 271 ''',
 272                  c_name=c_name(variants.tag_member.name))
 273
 274     for var in variants.variants:
 275         # TODO ugly special case for simple union
 276         simple_union_type = var.simple_union_type()
 277         ret += mcgen('''
 278     case %(case)s:
 279 ''',
 280                      case=c_enum_const(variants.tag_member.type.name,
 281                                        var.name,
 282                                        variants.tag_member.type.prefix))
 283         if simple_union_type:
 284             ret += mcgen('''
 285         visit_type_%(c_type)s(v, "data", &(*obj)->u.%(c_name)s, &err);
 286 ''',
 287                          c_type=simple_union_type.c_name(),
 288                          c_name=c_name(var.name))
 289         else:
 290             ret += mcgen('''
 291         visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err);
 292 ''',
 293                          c_type=var.type.c_name(),
 294                          c_name=c_name(var.name))
 295         ret += mcgen('''
 296         break;
 297 ''')
 298
 299     ret += mcgen('''
 300     default:
 301         abort();
 302     }
 303 out_obj:
 304     error_propagate(errp, err);
 305     err = NULL;
 306     visit_end_struct(v, &err);
 307 out:
 308     error_propagate(errp, err);
 309 }
 310 ''')
 311
 312     return ret
 313
 314
 315 class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
 316     def __init__(self):
 317         self.decl = None
 318         self.defn = None
 319         self._btin = None
 320
 321     def visit_begin(self, schema):
 322         self.decl = ''
 323         self.defn = ''
 324         self._btin = guardstart('QAPI_VISIT_BUILTIN')
 325
 326     def visit_end(self):
 327         # To avoid header dependency hell, we always generate
 328         # declarations for built-in types in our header files and
 329         # simply guard them.  See also do_builtins (command line
 330         # option -b).
 331         self._btin += guardend('QAPI_VISIT_BUILTIN')
 332         self.decl = self._btin + self.decl
 333         self._btin = None
 334
 335     def visit_needed(self, entity):
 336         # Visit everything except implicit objects
 337         return not (entity.is_implicit() and
 338                     isinstance(entity, QAPISchemaObjectType))
 339
 340     def visit_enum_type(self, name, info, values, prefix):
 341         # Special case for our lone builtin enum type
 342         # TODO use something cleaner than existence of info
 343         if not info:
 344             self._btin += gen_visit_decl(name, scalar=True)
 345             if do_builtins:
 346                 self.defn += gen_visit_enum(name)
 347         else:
 348             self.decl += gen_visit_decl(name, scalar=True)
 349             self.defn += gen_visit_enum(name)
 350
 351     def visit_array_type(self, name, info, element_type):
 352         decl = gen_visit_decl(name)
 353         defn = gen_visit_list(name, element_type)
 354         if isinstance(element_type, QAPISchemaBuiltinType):
 355             self._btin += decl
 356             if do_builtins:
 357                 self.defn += defn
 358         else:
 359             self.decl += decl
 360             self.defn += defn
 361
 362     def visit_object_type(self, name, info, base, members, variants):
 363         self.decl += gen_visit_decl(name)
 364         if variants:
 365             self.defn += gen_visit_union(name, base, members, variants)
 366         else:
 367             self.defn += gen_visit_struct(name, base, members)
 368
 369     def visit_alternate_type(self, name, info, variants):
 370         self.decl += gen_visit_decl(name)
 371         self.defn += gen_visit_alternate(name, variants)
 372
 373 # If you link code generated from multiple schemata, you want only one
 374 # instance of the code for built-in types.  Generate it only when
 375 # do_builtins, enabled by command line option -b.  See also
 376 # QAPISchemaGenVisitVisitor.visit_end().
 377 do_builtins = False
 378
 379 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 380     parse_command_line("b", ["builtins"])
 381
 382 for o, a in opts:
 383     if o in ("-b", "--builtins"):
 384         do_builtins = True
 385
 386 c_comment = '''
 387 /*
 388  * schema-defined QAPI visitor functions
 389  *
 390  * Copyright IBM, Corp. 2011
 391  *
 392  * Authors:
 393  *  Anthony Liguori   <aliguori@us.ibm.com>
 394  *
 395  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 396  * See the COPYING.LIB file in the top-level directory.
 397  *
 398  */
 399 '''
 400 h_comment = '''
 401 /*
 402  * schema-defined QAPI visitor functions
 403  *
 404  * Copyright IBM, Corp. 2011
 405  *
 406  * Authors:
 407  *  Anthony Liguori   <aliguori@us.ibm.com>
 408  *
 409  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 410  * See the COPYING.LIB file in the top-level directory.
 411  *
 412  */
 413 '''
 414
 415 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 416                             'qapi-visit.c', 'qapi-visit.h',
 417                             c_comment, h_comment)
 418
 419 fdef.write(mcgen('''
 420 #include "qemu/osdep.h"
 421 #include "qemu-common.h"
 422 #include "%(prefix)sqapi-visit.h"
 423 ''',
 424                  prefix=prefix))
 425
 426 fdecl.write(mcgen('''
 427 #include "qapi/visitor.h"
 428 #include "qapi/qmp/qerror.h"
 429 #include "%(prefix)sqapi-types.h"
 430
 431 ''',
 432                   prefix=prefix))
 433
 434 schema = QAPISchema(input_file)
 435 gen = QAPISchemaGenVisitVisitor()
 436 schema.visit(gen)
 437 fdef.write(gen.defn)
 438 fdecl.write(gen.decl)
 439
 440 close_output(fdef, fdecl)