scripts/qapi/visit.py

   1 """
   2 QAPI visitor generator
   3
   4 Copyright IBM, Corp. 2011
   5 Copyright (C) 2014-2018 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
  16 from typing import List, Optional, Sequence
  17
  18 from .common import (
  19     c_enum_const,
  20     c_name,
  21     gen_endif,
  22     gen_if,
  23     indent,
  24     mcgen,
  25 )
  26 from .gen import QAPISchemaModularCVisitor, ifcontext
  27 from .schema import (
  28     QAPISchema,
  29     QAPISchemaEnumMember,
  30     QAPISchemaEnumType,
  31     QAPISchemaFeature,
  32     QAPISchemaObjectType,
  33     QAPISchemaObjectTypeMember,
  34     QAPISchemaType,
  35     QAPISchemaVariants,
  36 )
  37 from .source import QAPISourceInfo
  38
  39
  40 def gen_visit_decl(name: str, scalar: bool = False) -> str:
  41     c_type = c_name(name) + ' *'
  42     if not scalar:
  43         c_type += '*'
  44     return mcgen('''
  45
  46 bool visit_type_%(c_name)s(Visitor *v, const char *name,
  47                  %(c_type)sobj, Error **errp);
  48 ''',
  49                  c_name=c_name(name), c_type=c_type)
  50
  51
  52 def gen_visit_members_decl(name: str) -> str:
  53     return mcgen('''
  54
  55 bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
  56 ''',
  57                  c_name=c_name(name))
  58
  59
  60 def gen_visit_object_members(name: str,
  61                              base: Optional[QAPISchemaObjectType],
  62                              members: List[QAPISchemaObjectTypeMember],
  63                              variants: Optional[QAPISchemaVariants]) -> str:
  64     ret = mcgen('''
  65
  66 bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
  67 {
  68 ''',
  69                 c_name=c_name(name))
  70
  71     if base:
  72         ret += mcgen('''
  73     if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) {
  74         return false;
  75     }
  76 ''',
  77                      c_type=base.c_name())
  78
  79     for memb in members:
  80         deprecated = 'deprecated' in [f.name for f in memb.features]
  81         ret += gen_if(memb.ifcond)
  82         if memb.optional:
  83             ret += mcgen('''
  84     if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
  85 ''',
  86                          name=memb.name, c_name=c_name(memb.name))
  87             indent.increase()
  88         if deprecated:
  89             ret += mcgen('''
  90     if (!visit_deprecated_accept(v, "%(name)s", errp)) {
  91         return false;
  92     }
  93     if (visit_deprecated(v, "%(name)s")) {
  94 ''',
  95                          name=memb.name)
  96             indent.increase()
  97         ret += mcgen('''
  98     if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) {
  99         return false;
 100     }
 101 ''',
 102                      c_type=memb.type.c_name(), name=memb.name,
 103                      c_name=c_name(memb.name))
 104         if deprecated:
 105             indent.decrease()
 106             ret += mcgen('''
 107     }
 108 ''')
 109         if memb.optional:
 110             indent.decrease()
 111             ret += mcgen('''
 112     }
 113 ''')
 114         ret += gen_endif(memb.ifcond)
 115
 116     if variants:
 117         tag_member = variants.tag_member
 118         assert isinstance(tag_member.type, QAPISchemaEnumType)
 119
 120         ret += mcgen('''
 121     switch (obj->%(c_name)s) {
 122 ''',
 123                      c_name=c_name(tag_member.name))
 124
 125         for var in variants.variants:
 126             case_str = c_enum_const(tag_member.type.name, var.name,
 127                                     tag_member.type.prefix)
 128             ret += gen_if(var.ifcond)
 129             if var.type.name == 'q_empty':
 130                 # valid variant and nothing to do
 131                 ret += mcgen('''
 132     case %(case)s:
 133         break;
 134 ''',
 135                              case=case_str)
 136             else:
 137                 ret += mcgen('''
 138     case %(case)s:
 139         return visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, errp);
 140 ''',
 141                              case=case_str,
 142                              c_type=var.type.c_name(), c_name=c_name(var.name))
 143
 144             ret += gen_endif(var.ifcond)
 145         ret += mcgen('''
 146     default:
 147         abort();
 148     }
 149 ''')
 150
 151     ret += mcgen('''
 152     return true;
 153 }
 154 ''')
 155     return ret
 156
 157
 158 def gen_visit_list(name: str, element_type: QAPISchemaType) -> str:
 159     return mcgen('''
 160
 161 bool visit_type_%(c_name)s(Visitor *v, const char *name,
 162                  %(c_name)s **obj, Error **errp)
 163 {
 164     bool ok = false;
 165     %(c_name)s *tail;
 166     size_t size = sizeof(**obj);
 167
 168     if (!visit_start_list(v, name, (GenericList **)obj, size, errp)) {
 169         return false;
 170     }
 171
 172     for (tail = *obj; tail;
 173          tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
 174         if (!visit_type_%(c_elt_type)s(v, NULL, &tail->value, errp)) {
 175             goto out_obj;
 176         }
 177     }
 178
 179     ok = visit_check_list(v, errp);
 180 out_obj:
 181     visit_end_list(v, (void **)obj);
 182     if (!ok && visit_is_input(v)) {
 183         qapi_free_%(c_name)s(*obj);
 184         *obj = NULL;
 185     }
 186     return ok;
 187 }
 188 ''',
 189                  c_name=c_name(name), c_elt_type=element_type.c_name())
 190
 191
 192 def gen_visit_enum(name: str) -> str:
 193     return mcgen('''
 194
 195 bool visit_type_%(c_name)s(Visitor *v, const char *name,
 196                  %(c_name)s *obj, Error **errp)
 197 {
 198     int value = *obj;
 199     bool ok = visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
 200     *obj = value;
 201     return ok;
 202 }
 203 ''',
 204                  c_name=c_name(name))
 205
 206
 207 def gen_visit_alternate(name: str, variants: QAPISchemaVariants) -> str:
 208     ret = mcgen('''
 209
 210 bool visit_type_%(c_name)s(Visitor *v, const char *name,
 211                  %(c_name)s **obj, Error **errp)
 212 {
 213     bool ok = false;
 214
 215     if (!visit_start_alternate(v, name, (GenericAlternate **)obj,
 216                                sizeof(**obj), errp)) {
 217         return false;
 218     }
 219     if (!*obj) {
 220         /* incomplete */
 221         assert(visit_is_dealloc(v));
 222         ok = true;
 223         goto out_obj;
 224     }
 225     switch ((*obj)->type) {
 226 ''',
 227                 c_name=c_name(name))
 228
 229     for var in variants.variants:
 230         ret += gen_if(var.ifcond)
 231         ret += mcgen('''
 232     case %(case)s:
 233 ''',
 234                      case=var.type.alternate_qtype())
 235         if isinstance(var.type, QAPISchemaObjectType):
 236             ret += mcgen('''
 237         if (!visit_start_struct(v, name, NULL, 0, errp)) {
 238             break;
 239         }
 240         if (visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, errp)) {
 241             ok = visit_check_struct(v, errp);
 242         }
 243         visit_end_struct(v, NULL);
 244 ''',
 245                          c_type=var.type.c_name(),
 246                          c_name=c_name(var.name))
 247         else:
 248             ret += mcgen('''
 249         ok = visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, errp);
 250 ''',
 251                          c_type=var.type.c_name(),
 252                          c_name=c_name(var.name))
 253         ret += mcgen('''
 254         break;
 255 ''')
 256         ret += gen_endif(var.ifcond)
 257
 258     ret += mcgen('''
 259     case QTYPE_NONE:
 260         abort();
 261     default:
 262         assert(visit_is_input(v));
 263         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 264                    "%(name)s");
 265         /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
 266         g_free(*obj);
 267         *obj = NULL;
 268     }
 269 out_obj:
 270     visit_end_alternate(v, (void **)obj);
 271     if (!ok && visit_is_input(v)) {
 272         qapi_free_%(c_name)s(*obj);
 273         *obj = NULL;
 274     }
 275     return ok;
 276 }
 277 ''',
 278                  name=name, c_name=c_name(name))
 279
 280     return ret
 281
 282
 283 def gen_visit_object(name: str) -> str:
 284     return mcgen('''
 285
 286 bool visit_type_%(c_name)s(Visitor *v, const char *name,
 287                  %(c_name)s **obj, Error **errp)
 288 {
 289     bool ok = false;
 290
 291     if (!visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), errp)) {
 292         return false;
 293     }
 294     if (!*obj) {
 295         /* incomplete */
 296         assert(visit_is_dealloc(v));
 297         ok = true;
 298         goto out_obj;
 299     }
 300     if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
 301         goto out_obj;
 302     }
 303     ok = visit_check_struct(v, errp);
 304 out_obj:
 305     visit_end_struct(v, (void **)obj);
 306     if (!ok && visit_is_input(v)) {
 307         qapi_free_%(c_name)s(*obj);
 308         *obj = NULL;
 309     }
 310     return ok;
 311 }
 312 ''',
 313                  c_name=c_name(name))
 314
 315
 316 class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
 317
 318     def __init__(self, prefix: str):
 319         super().__init__(
 320             prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
 321             ' * Built-in QAPI visitors', __doc__)
 322
 323     def _begin_builtin_module(self) -> None:
 324         self._genc.preamble_add(mcgen('''
 325 #include "qemu/osdep.h"
 326 #include "qapi/error.h"
 327 #include "qapi/qapi-builtin-visit.h"
 328 '''))
 329         self._genh.preamble_add(mcgen('''
 330 #include "qapi/visitor.h"
 331 #include "qapi/qapi-builtin-types.h"
 332
 333 '''))
 334
 335     def _begin_user_module(self, name: str) -> None:
 336         types = self._module_basename('qapi-types', name)
 337         visit = self._module_basename('qapi-visit', name)
 338         self._genc.preamble_add(mcgen('''
 339 #include "qemu/osdep.h"
 340 #include "qapi/error.h"
 341 #include "qapi/qmp/qerror.h"
 342 #include "%(visit)s.h"
 343 ''',
 344                                       visit=visit))
 345         self._genh.preamble_add(mcgen('''
 346 #include "qapi/qapi-builtin-visit.h"
 347 #include "%(types)s.h"
 348
 349 ''',
 350                                       types=types))
 351
 352     def visit_enum_type(self,
 353                         name: str,
 354                         info: Optional[QAPISourceInfo],
 355                         ifcond: Sequence[str],
 356                         features: List[QAPISchemaFeature],
 357                         members: List[QAPISchemaEnumMember],
 358                         prefix: Optional[str]) -> None:
 359         with ifcontext(ifcond, self._genh, self._genc):
 360             self._genh.add(gen_visit_decl(name, scalar=True))
 361             self._genc.add(gen_visit_enum(name))
 362
 363     def visit_array_type(self,
 364                          name: str,
 365                          info: Optional[QAPISourceInfo],
 366                          ifcond: Sequence[str],
 367                          element_type: QAPISchemaType) -> None:
 368         with ifcontext(ifcond, self._genh, self._genc):
 369             self._genh.add(gen_visit_decl(name))
 370             self._genc.add(gen_visit_list(name, element_type))
 371
 372     def visit_object_type(self,
 373                           name: str,
 374                           info: Optional[QAPISourceInfo],
 375                           ifcond: Sequence[str],
 376                           features: List[QAPISchemaFeature],
 377                           base: Optional[QAPISchemaObjectType],
 378                           members: List[QAPISchemaObjectTypeMember],
 379                           variants: Optional[QAPISchemaVariants]) -> None:
 380         # Nothing to do for the special empty builtin
 381         if name == 'q_empty':
 382             return
 383         with ifcontext(ifcond, self._genh, self._genc):
 384             self._genh.add(gen_visit_members_decl(name))
 385             self._genc.add(gen_visit_object_members(name, base,
 386                                                     members, variants))
 387             # TODO Worth changing the visitor signature, so we could
 388             # directly use rather than repeat type.is_implicit()?
 389             if not name.startswith('q_'):
 390                 # only explicit types need an allocating visit
 391                 self._genh.add(gen_visit_decl(name))
 392                 self._genc.add(gen_visit_object(name))
 393
 394     def visit_alternate_type(self,
 395                              name: str,
 396                              info: Optional[QAPISourceInfo],
 397                              ifcond: Sequence[str],
 398                              features: List[QAPISchemaFeature],
 399                              variants: QAPISchemaVariants) -> None:
 400         with ifcontext(ifcond, self._genh, self._genc):
 401             self._genh.add(gen_visit_decl(name))
 402             self._genc.add(gen_visit_alternate(name, variants))
 403
 404
 405 def gen_visit(schema: QAPISchema,
 406               output_dir: str,
 407               prefix: str,
 408               opt_builtins: bool) -> None:
 409     vis = QAPISchemaGenVisitVisitor(prefix)
 410     schema.visit(vis)
 411     vis.write(output_dir, opt_builtins)