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