scripts/qapi-visit.py

   1 #
   2 # QAPI visitor generator
   3 #
   4 # Copyright IBM, Corp. 2011
   5 # Copyright (C) 2014-2016 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
  17
  18 def gen_visit_decl(name, scalar=False):
  19     c_type = c_name(name) + ' *'
  20     if not scalar:
  21         c_type += '*'
  22     return mcgen('''
  23 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
  24 ''',
  25                  c_name=c_name(name), c_type=c_type)
  26
  27
  28 def gen_visit_members_decl(name):
  29     return mcgen('''
  30
  31 void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
  32 ''',
  33                  c_name=c_name(name))
  34
  35
  36 def gen_visit_object_members(name, base, members, variants):
  37     ret = mcgen('''
  38
  39 void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
  40 {
  41     Error *err = NULL;
  42
  43 ''',
  44                 c_name=c_name(name))
  45
  46     if base:
  47         ret += mcgen('''
  48     visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, &err);
  49     if (err) {
  50         goto out;
  51     }
  52 ''',
  53                      c_type=base.c_name())
  54
  55     for memb in members:
  56         if memb.optional:
  57             ret += mcgen('''
  58     if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
  59 ''',
  60                          name=memb.name, c_name=c_name(memb.name))
  61             push_indent()
  62         ret += mcgen('''
  63     visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, &err);
  64     if (err) {
  65         goto out;
  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
  76     if variants:
  77         ret += mcgen('''
  78     switch (obj->%(c_name)s) {
  79 ''',
  80                      c_name=c_name(variants.tag_member.name))
  81
  82         for var in variants.variants:
  83             ret += mcgen('''
  84     case %(case)s:
  85         visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
  86         break;
  87 ''',
  88                          case=c_enum_const(variants.tag_member.type.name,
  89                                            var.name,
  90                                            variants.tag_member.type.prefix),
  91                          c_type=var.type.c_name(), c_name=c_name(var.name))
  92
  93         ret += mcgen('''
  94     default:
  95         abort();
  96     }
  97 ''')
  98
  99     # 'goto out' produced for base, for each member, and if variants were
 100     # present
 101     if base or members or variants:
 102         ret += mcgen('''
 103
 104 out:
 105 ''')
 106     ret += mcgen('''
 107     error_propagate(errp, err);
 108 }
 109 ''')
 110     return ret
 111
 112
 113 def gen_visit_list(name, element_type):
 114     return mcgen('''
 115
 116 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 117 {
 118     Error *err = NULL;
 119     %(c_name)s *tail;
 120     size_t size = sizeof(**obj);
 121
 122     visit_start_list(v, name, (GenericList **)obj, size, &err);
 123     if (err) {
 124         goto out;
 125     }
 126
 127     for (tail = *obj; tail;
 128          tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
 129         visit_type_%(c_elt_type)s(v, NULL, &tail->value, &err);
 130         if (err) {
 131             break;
 132         }
 133     }
 134
 135     if (!err) {
 136         visit_check_list(v, &err);
 137     }
 138     visit_end_list(v, (void **)obj);
 139     if (err && visit_is_input(v)) {
 140         qapi_free_%(c_name)s(*obj);
 141         *obj = NULL;
 142     }
 143 out:
 144     error_propagate(errp, err);
 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 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
 154 {
 155     int value = *obj;
 156     visit_type_enum(v, name, &value, %(c_name)s_lookup, errp);
 157     *obj = value;
 158 }
 159 ''',
 160                  c_name=c_name(name))
 161
 162
 163 def gen_visit_alternate(name, variants):
 164     ret = mcgen('''
 165
 166 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 167 {
 168     Error *err = NULL;
 169
 170     visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
 171                           &err);
 172     if (err) {
 173         goto out;
 174     }
 175     if (!*obj) {
 176         goto out_obj;
 177     }
 178     switch ((*obj)->type) {
 179 ''',
 180                  c_name=c_name(name))
 181
 182     for var in variants.variants:
 183         ret += mcgen('''
 184     case %(case)s:
 185 ''',
 186                      case=var.type.alternate_qtype())
 187         if isinstance(var.type, QAPISchemaObjectType):
 188             ret += mcgen('''
 189         visit_start_struct(v, name, NULL, 0, &err);
 190         if (err) {
 191             break;
 192         }
 193         visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
 194         if (!err) {
 195             visit_check_struct(v, &err);
 196         }
 197         visit_end_struct(v, NULL);
 198 ''',
 199                          c_type=var.type.c_name(),
 200                          c_name=c_name(var.name))
 201         else:
 202             ret += mcgen('''
 203         visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
 204 ''',
 205                          c_type=var.type.c_name(),
 206                          c_name=c_name(var.name))
 207         ret += mcgen('''
 208         break;
 209 ''')
 210
 211     ret += mcgen('''
 212     case QTYPE_NONE:
 213         abort();
 214     default:
 215         error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 216                    "%(name)s");
 217     }
 218 out_obj:
 219     visit_end_alternate(v, (void **)obj);
 220     if (err && visit_is_input(v)) {
 221         qapi_free_%(c_name)s(*obj);
 222         *obj = NULL;
 223     }
 224 out:
 225     error_propagate(errp, err);
 226 }
 227 ''',
 228                  name=name, c_name=c_name(name))
 229
 230     return ret
 231
 232
 233 def gen_visit_object(name, base, members, variants):
 234     return mcgen('''
 235
 236 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 237 {
 238     Error *err = NULL;
 239
 240     visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
 241     if (err) {
 242         goto out;
 243     }
 244     if (!*obj) {
 245         goto out_obj;
 246     }
 247     visit_type_%(c_name)s_members(v, *obj, &err);
 248     if (err) {
 249         goto out_obj;
 250     }
 251     visit_check_struct(v, &err);
 252 out_obj:
 253     visit_end_struct(v, (void **)obj);
 254     if (err && visit_is_input(v)) {
 255         qapi_free_%(c_name)s(*obj);
 256         *obj = NULL;
 257     }
 258 out:
 259     error_propagate(errp, err);
 260 }
 261 ''',
 262                  c_name=c_name(name))
 263
 264
 265 class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
 266     def __init__(self):
 267         self.decl = None
 268         self.defn = None
 269         self._btin = None
 270
 271     def visit_begin(self, schema):
 272         self.decl = ''
 273         self.defn = ''
 274         self._btin = guardstart('QAPI_VISIT_BUILTIN')
 275
 276     def visit_end(self):
 277         # To avoid header dependency hell, we always generate
 278         # declarations for built-in types in our header files and
 279         # simply guard them.  See also do_builtins (command line
 280         # option -b).
 281         self._btin += guardend('QAPI_VISIT_BUILTIN')
 282         self.decl = self._btin + self.decl
 283         self._btin = None
 284
 285     def visit_enum_type(self, name, info, values, prefix):
 286         # Special case for our lone builtin enum type
 287         # TODO use something cleaner than existence of info
 288         if not info:
 289             self._btin += gen_visit_decl(name, scalar=True)
 290             if do_builtins:
 291                 self.defn += gen_visit_enum(name)
 292         else:
 293             self.decl += gen_visit_decl(name, scalar=True)
 294             self.defn += gen_visit_enum(name)
 295
 296     def visit_array_type(self, name, info, element_type):
 297         decl = gen_visit_decl(name)
 298         defn = gen_visit_list(name, element_type)
 299         if isinstance(element_type, QAPISchemaBuiltinType):
 300             self._btin += decl
 301             if do_builtins:
 302                 self.defn += defn
 303         else:
 304             self.decl += decl
 305             self.defn += defn
 306
 307     def visit_object_type(self, name, info, base, members, variants):
 308         # Nothing to do for the special empty builtin
 309         if name == 'q_empty':
 310             return
 311         self.decl += gen_visit_members_decl(name)
 312         self.defn += gen_visit_object_members(name, base, members, variants)
 313         # TODO Worth changing the visitor signature, so we could
 314         # directly use rather than repeat type.is_implicit()?
 315         if not name.startswith('q_'):
 316             # only explicit types need an allocating visit
 317             self.decl += gen_visit_decl(name)
 318             self.defn += gen_visit_object(name, base, members, variants)
 319
 320     def visit_alternate_type(self, name, info, variants):
 321         self.decl += gen_visit_decl(name)
 322         self.defn += gen_visit_alternate(name, variants)
 323
 324 # If you link code generated from multiple schemata, you want only one
 325 # instance of the code for built-in types.  Generate it only when
 326 # do_builtins, enabled by command line option -b.  See also
 327 # QAPISchemaGenVisitVisitor.visit_end().
 328 do_builtins = False
 329
 330 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 331     parse_command_line('b', ['builtins'])
 332
 333 for o, a in opts:
 334     if o in ('-b', '--builtins'):
 335         do_builtins = True
 336
 337 c_comment = '''
 338 /*
 339  * schema-defined QAPI visitor functions
 340  *
 341  * Copyright IBM, Corp. 2011
 342  *
 343  * Authors:
 344  *  Anthony Liguori   <aliguori@us.ibm.com>
 345  *
 346  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 347  * See the COPYING.LIB file in the top-level directory.
 348  *
 349  */
 350 '''
 351 h_comment = '''
 352 /*
 353  * schema-defined QAPI visitor functions
 354  *
 355  * Copyright IBM, Corp. 2011
 356  *
 357  * Authors:
 358  *  Anthony Liguori   <aliguori@us.ibm.com>
 359  *
 360  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 361  * See the COPYING.LIB file in the top-level directory.
 362  *
 363  */
 364 '''
 365
 366 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 367                             'qapi-visit.c', 'qapi-visit.h',
 368                             c_comment, h_comment)
 369
 370 fdef.write(mcgen('''
 371 #include "qemu/osdep.h"
 372 #include "qemu-common.h"
 373 #include "qapi/error.h"
 374 #include "%(prefix)sqapi-visit.h"
 375 ''',
 376                  prefix=prefix))
 377
 378 fdecl.write(mcgen('''
 379 #include "qapi/visitor.h"
 380 #include "qapi/qmp/qerror.h"
 381 #include "%(prefix)sqapi-types.h"
 382
 383 ''',
 384                   prefix=prefix))
 385
 386 schema = QAPISchema(input_file)
 387 gen = QAPISchemaGenVisitVisitor()
 388 schema.visit(gen)
 389 fdef.write(gen.defn)
 390 fdecl.write(gen.decl)
 391
 392 close_output(fdef, fdecl)