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