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