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     return mcgen('''
 176
 177 void visit_type_%(c_name)s(Visitor *v, %(c_name)s *obj, const char *name, Error **errp)
 178 {
 179     visit_type_enum(v, (int *)obj, %(c_name)s_lookup, "%(name)s", name, errp);
 180 }
 181 ''',
 182                  c_name=c_name(name), name=name)
 183
 184
 185 def gen_visit_alternate(name, variants):
 186     ret = mcgen('''
 187
 188 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 189 {
 190     Error *err = NULL;
 191
 192     visit_start_implicit_struct(v, (void**) obj, sizeof(%(c_name)s), &err);
 193     if (err) {
 194         goto out;
 195     }
 196     visit_get_next_type(v, (int*) &(*obj)->type, %(c_name)s_qtypes, name, &err);
 197     if (err) {
 198         goto out_obj;
 199     }
 200     switch ((*obj)->type) {
 201 ''',
 202                 c_name=c_name(name))
 203
 204     for var in variants.variants:
 205         ret += mcgen('''
 206     case %(case)s:
 207         visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, name, &err);
 208         break;
 209 ''',
 210                      case=c_enum_const(variants.tag_member.type.name,
 211                                        var.name),
 212                      c_type=var.type.c_name(),
 213                      c_name=c_name(var.name))
 214
 215     ret += mcgen('''
 216     default:
 217         abort();
 218     }
 219 out_obj:
 220     error_propagate(errp, err);
 221     err = NULL;
 222     visit_end_implicit_struct(v, &err);
 223 out:
 224     error_propagate(errp, err);
 225 }
 226 ''')
 227
 228     return ret
 229
 230
 231 def gen_visit_union(name, base, variants):
 232     ret = ''
 233
 234     if base:
 235         ret += gen_visit_fields_decl(base)
 236
 237     for var in variants.variants:
 238         # Ugly special case for simple union TODO get rid of it
 239         if not var.simple_union_type():
 240             ret += gen_visit_implicit_struct(var.type)
 241
 242     ret += mcgen('''
 243
 244 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
 245 {
 246     Error *err = NULL;
 247
 248     visit_start_struct(v, (void **)obj, "%(name)s", name, sizeof(%(c_name)s), &err);
 249     if (err) {
 250         goto out;
 251     }
 252     if (!*obj) {
 253         goto out_obj;
 254     }
 255 ''',
 256                  c_name=c_name(name), name=name)
 257
 258     if base:
 259         ret += mcgen('''
 260     visit_type_%(c_name)s_fields(v, (%(c_name)s **)obj, &err);
 261 ''',
 262                      c_name=base.c_name())
 263     else:
 264         ret += mcgen('''
 265     visit_type_%(c_type)s(v, &(*obj)->%(c_name)s, "%(name)s", &err);
 266 ''',
 267                      c_type=variants.tag_member.type.c_name(),
 268                      c_name=c_name(variants.tag_member.name),
 269                      name=variants.tag_member.name)
 270     ret += gen_err_check(label='out_obj')
 271     ret += mcgen('''
 272     if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) {
 273         goto out_obj;
 274     }
 275     switch ((*obj)->%(c_name)s) {
 276 ''',
 277                  c_name=c_name(variants.tag_member.name))
 278
 279     for var in variants.variants:
 280         # TODO ugly special case for simple union
 281         simple_union_type = var.simple_union_type()
 282         ret += mcgen('''
 283     case %(case)s:
 284 ''',
 285                      case=c_enum_const(variants.tag_member.type.name,
 286                                        var.name))
 287         if simple_union_type:
 288             ret += mcgen('''
 289         visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, "data", &err);
 290 ''',
 291                          c_type=simple_union_type.c_name(),
 292                          c_name=c_name(var.name))
 293         else:
 294             ret += mcgen('''
 295         visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err);
 296 ''',
 297                          c_type=var.type.c_name(),
 298                          c_name=c_name(var.name))
 299         ret += mcgen('''
 300         break;
 301 ''')
 302
 303     ret += mcgen('''
 304     default:
 305         abort();
 306     }
 307 out_obj:
 308     error_propagate(errp, err);
 309     err = NULL;
 310     if (*obj) {
 311         visit_end_union(v, !!(*obj)->u.data, &err);
 312     }
 313     error_propagate(errp, err);
 314     err = NULL;
 315     visit_end_struct(v, &err);
 316 out:
 317     error_propagate(errp, err);
 318 }
 319 ''')
 320
 321     return ret
 322
 323
 324 class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
 325     def __init__(self):
 326         self.decl = None
 327         self.defn = None
 328         self._btin = None
 329
 330     def visit_begin(self, schema):
 331         self.decl = ''
 332         self.defn = ''
 333         self._btin = guardstart('QAPI_VISIT_BUILTIN')
 334
 335     def visit_end(self):
 336         # To avoid header dependency hell, we always generate
 337         # declarations for built-in types in our header files and
 338         # simply guard them.  See also do_builtins (command line
 339         # option -b).
 340         self._btin += guardend('QAPI_VISIT_BUILTIN')
 341         self.decl = self._btin + self.decl
 342         self._btin = None
 343
 344     def visit_needed(self, entity):
 345         # Visit everything except implicit objects
 346         return not (entity.is_implicit() and
 347                     isinstance(entity, QAPISchemaObjectType))
 348
 349     def visit_enum_type(self, name, info, values, prefix):
 350         self.decl += gen_visit_decl(name, scalar=True)
 351         self.defn += gen_visit_enum(name)
 352
 353     def visit_array_type(self, name, info, element_type):
 354         decl = gen_visit_decl(name)
 355         defn = gen_visit_list(name, element_type)
 356         if isinstance(element_type, QAPISchemaBuiltinType):
 357             self._btin += decl
 358             if do_builtins:
 359                 self.defn += defn
 360         else:
 361             self.decl += decl
 362             self.defn += defn
 363
 364     def visit_object_type(self, name, info, base, members, variants):
 365         self.decl += gen_visit_decl(name)
 366         if variants:
 367             assert not members      # not implemented
 368             self.defn += gen_visit_union(name, base, variants)
 369         else:
 370             self.defn += gen_visit_struct(name, base, members)
 371
 372     def visit_alternate_type(self, name, info, variants):
 373         self.decl += gen_visit_decl(name)
 374         self.defn += gen_visit_alternate(name, variants)
 375
 376 # If you link code generated from multiple schemata, you want only one
 377 # instance of the code for built-in types.  Generate it only when
 378 # do_builtins, enabled by command line option -b.  See also
 379 # QAPISchemaGenVisitVisitor.visit_end().
 380 do_builtins = False
 381
 382 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 383     parse_command_line("b", ["builtins"])
 384
 385 for o, a in opts:
 386     if o in ("-b", "--builtins"):
 387         do_builtins = True
 388
 389 c_comment = '''
 390 /*
 391  * schema-defined QAPI visitor functions
 392  *
 393  * Copyright IBM, Corp. 2011
 394  *
 395  * Authors:
 396  *  Anthony Liguori   <aliguori@us.ibm.com>
 397  *
 398  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 399  * See the COPYING.LIB file in the top-level directory.
 400  *
 401  */
 402 '''
 403 h_comment = '''
 404 /*
 405  * schema-defined QAPI visitor functions
 406  *
 407  * Copyright IBM, Corp. 2011
 408  *
 409  * Authors:
 410  *  Anthony Liguori   <aliguori@us.ibm.com>
 411  *
 412  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 413  * See the COPYING.LIB file in the top-level directory.
 414  *
 415  */
 416 '''
 417
 418 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 419                             'qapi-visit.c', 'qapi-visit.h',
 420                             c_comment, h_comment)
 421
 422 fdef.write(mcgen('''
 423 #include "qemu-common.h"
 424 #include "%(prefix)sqapi-visit.h"
 425 ''',
 426                  prefix=prefix))
 427
 428 fdecl.write(mcgen('''
 429 #include "qapi/visitor.h"
 430 #include "%(prefix)sqapi-types.h"
 431
 432 ''',
 433                   prefix=prefix))
 434
 435 schema = QAPISchema(input_file)
 436 gen = QAPISchemaGenVisitVisitor()
 437 schema.visit(gen)
 438 fdef.write(gen.defn)
 439 fdecl.write(gen.decl)
 440
 441 close_output(fdef, fdecl)