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 import re
  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 ''',
  51                      c_type=base.c_name())
  52         ret += gen_err_check()
  53
  54     for memb in members:
  55         if memb.optional:
  56             ret += mcgen('''
  57     if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
  58 ''',
  59                          name=memb.name, c_name=c_name(memb.name))
  60             push_indent()
  61         ret += mcgen('''
  62     visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, &err);
  63 ''',
  64                      c_type=memb.type.c_name(), name=memb.name,
  65                      c_name=c_name(memb.name))
  66         ret += gen_err_check()
  67         if memb.optional:
  68             pop_indent()
  69             ret += mcgen('''
  70     }
  71 ''')
  72
  73     if variants:
  74         ret += mcgen('''
  75     switch (obj->%(c_name)s) {
  76 ''',
  77                      c_name=c_name(variants.tag_member.name))
  78
  79         for var in variants.variants:
  80             ret += mcgen('''
  81     case %(case)s:
  82         visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
  83         break;
  84 ''',
  85                          case=c_enum_const(variants.tag_member.type.name,
  86                                            var.name,
  87                                            variants.tag_member.type.prefix),
  88                          c_type=var.type.c_name(), c_name=c_name(var.name))
  89
  90         ret += mcgen('''
  91     default:
  92         abort();
  93     }
  94 ''')
  95
  96     # 'goto out' produced for base, for each member, and if variants were
  97     # present
  98     if base or members or variants:
  99         ret += mcgen('''
 100
 101 out:
 102 ''')
 103     ret += mcgen('''
 104     error_propagate(errp, err);
 105 }
 106 ''')
 107     return ret
 108
 109
 110 def gen_visit_list(name, element_type):
 111     # FIXME: if *obj is NULL on entry, and the first visit_next_list()
 112     # assigns to *obj, while a later one fails, we should clean up *obj
 113     # rather than leaving it non-NULL. As currently written, the caller must
 114     # call qapi_free_FOOList() to avoid a memory leak of the partial FOOList.
 115     return mcgen('''
 116
 117 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 118 {
 119     Error *err = NULL;
 120     GenericList *i, **prev;
 121
 122     visit_start_list(v, name, &err);
 123     if (err) {
 124         goto out;
 125     }
 126
 127     for (prev = (GenericList **)obj;
 128          !err && (i = visit_next_list(v, prev, sizeof(**obj))) != NULL;
 129          prev = &i) {
 130         %(c_name)s *native_i = (%(c_name)s *)i;
 131         visit_type_%(c_elt_type)s(v, NULL, &native_i->value, &err);
 132     }
 133
 134     visit_end_list(v);
 135 out:
 136     error_propagate(errp, err);
 137 }
 138 ''',
 139                  c_name=c_name(name), c_elt_type=element_type.c_name())
 140
 141
 142 def gen_visit_enum(name):
 143     return mcgen('''
 144
 145 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
 146 {
 147     int value = *obj;
 148     visit_type_enum(v, name, &value, %(c_name)s_lookup, errp);
 149     *obj = value;
 150 }
 151 ''',
 152                  c_name=c_name(name))
 153
 154
 155 def gen_visit_alternate(name, variants):
 156     promote_int = 'true'
 157     ret = ''
 158     for var in variants.variants:
 159         if var.type.alternate_qtype() == 'QTYPE_QINT':
 160             promote_int = 'false'
 161
 162     ret += mcgen('''
 163
 164 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 165 {
 166     Error *err = NULL;
 167
 168     visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
 169                           %(promote_int)s, &err);
 170     if (err) {
 171         goto out;
 172     }
 173     switch ((*obj)->type) {
 174 ''',
 175                  c_name=c_name(name), promote_int=promote_int)
 176
 177     for var in variants.variants:
 178         ret += mcgen('''
 179     case %(case)s:
 180 ''',
 181                      case=var.type.alternate_qtype())
 182         if isinstance(var.type, QAPISchemaObjectType):
 183             ret += mcgen('''
 184         visit_start_struct(v, name, NULL, 0, &err);
 185         if (err) {
 186             break;
 187         }
 188         visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
 189         error_propagate(errp, err);
 190         err = NULL;
 191         visit_end_struct(v, &err);
 192 ''',
 193                          c_type=var.type.c_name(),
 194                          c_name=c_name(var.name))
 195         else:
 196             ret += mcgen('''
 197         visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
 198 ''',
 199                          c_type=var.type.c_name(),
 200                          c_name=c_name(var.name))
 201         ret += mcgen('''
 202         break;
 203 ''')
 204
 205     ret += mcgen('''
 206     default:
 207         error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 208                    "%(name)s");
 209     }
 210     visit_end_alternate(v);
 211 out:
 212     error_propagate(errp, err);
 213 }
 214 ''',
 215                  name=name)
 216
 217     return ret
 218
 219
 220 def gen_visit_object(name, base, members, variants):
 221     # FIXME: if *obj is NULL on entry, and visit_start_struct() assigns to
 222     # *obj, but then visit_type_FOO_members() fails, we should clean up *obj
 223     # rather than leaving it non-NULL. As currently written, the caller must
 224     # call qapi_free_FOO() to avoid a memory leak of the partial FOO.
 225     return mcgen('''
 226
 227 void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 228 {
 229     Error *err = NULL;
 230
 231     visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
 232     if (err) {
 233         goto out;
 234     }
 235     if (!*obj) {
 236         goto out_obj;
 237     }
 238     visit_type_%(c_name)s_members(v, *obj, &err);
 239     error_propagate(errp, err);
 240     err = NULL;
 241 out_obj:
 242     visit_end_struct(v, &err);
 243 out:
 244     error_propagate(errp, err);
 245 }
 246 ''',
 247                  c_name=c_name(name))
 248
 249
 250 class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
 251     def __init__(self):
 252         self.decl = None
 253         self.defn = None
 254         self._btin = None
 255
 256     def visit_begin(self, schema):
 257         self.decl = ''
 258         self.defn = ''
 259         self._btin = guardstart('QAPI_VISIT_BUILTIN')
 260
 261     def visit_end(self):
 262         # To avoid header dependency hell, we always generate
 263         # declarations for built-in types in our header files and
 264         # simply guard them.  See also do_builtins (command line
 265         # option -b).
 266         self._btin += guardend('QAPI_VISIT_BUILTIN')
 267         self.decl = self._btin + self.decl
 268         self._btin = None
 269
 270     def visit_enum_type(self, name, info, values, prefix):
 271         # Special case for our lone builtin enum type
 272         # TODO use something cleaner than existence of info
 273         if not info:
 274             self._btin += gen_visit_decl(name, scalar=True)
 275             if do_builtins:
 276                 self.defn += gen_visit_enum(name)
 277         else:
 278             self.decl += gen_visit_decl(name, scalar=True)
 279             self.defn += gen_visit_enum(name)
 280
 281     def visit_array_type(self, name, info, element_type):
 282         decl = gen_visit_decl(name)
 283         defn = gen_visit_list(name, element_type)
 284         if isinstance(element_type, QAPISchemaBuiltinType):
 285             self._btin += decl
 286             if do_builtins:
 287                 self.defn += defn
 288         else:
 289             self.decl += decl
 290             self.defn += defn
 291
 292     def visit_object_type(self, name, info, base, members, variants):
 293         # Nothing to do for the special empty builtin
 294         if name == 'q_empty':
 295             return
 296         self.decl += gen_visit_members_decl(name)
 297         self.defn += gen_visit_object_members(name, base, members, variants)
 298         # TODO Worth changing the visitor signature, so we could
 299         # directly use rather than repeat type.is_implicit()?
 300         if not name.startswith('q_'):
 301             # only explicit types need an allocating visit
 302             self.decl += gen_visit_decl(name)
 303             self.defn += gen_visit_object(name, base, members, variants)
 304
 305     def visit_alternate_type(self, name, info, variants):
 306         self.decl += gen_visit_decl(name)
 307         self.defn += gen_visit_alternate(name, variants)
 308
 309 # If you link code generated from multiple schemata, you want only one
 310 # instance of the code for built-in types.  Generate it only when
 311 # do_builtins, enabled by command line option -b.  See also
 312 # QAPISchemaGenVisitVisitor.visit_end().
 313 do_builtins = False
 314
 315 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 316     parse_command_line("b", ["builtins"])
 317
 318 for o, a in opts:
 319     if o in ("-b", "--builtins"):
 320         do_builtins = True
 321
 322 c_comment = '''
 323 /*
 324  * schema-defined QAPI visitor functions
 325  *
 326  * Copyright IBM, Corp. 2011
 327  *
 328  * Authors:
 329  *  Anthony Liguori   <aliguori@us.ibm.com>
 330  *
 331  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 332  * See the COPYING.LIB file in the top-level directory.
 333  *
 334  */
 335 '''
 336 h_comment = '''
 337 /*
 338  * schema-defined QAPI visitor functions
 339  *
 340  * Copyright IBM, Corp. 2011
 341  *
 342  * Authors:
 343  *  Anthony Liguori   <aliguori@us.ibm.com>
 344  *
 345  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 346  * See the COPYING.LIB file in the top-level directory.
 347  *
 348  */
 349 '''
 350
 351 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 352                             'qapi-visit.c', 'qapi-visit.h',
 353                             c_comment, h_comment)
 354
 355 fdef.write(mcgen('''
 356 #include "qemu/osdep.h"
 357 #include "qemu-common.h"
 358 #include "%(prefix)sqapi-visit.h"
 359 ''',
 360                  prefix=prefix))
 361
 362 fdecl.write(mcgen('''
 363 #include "qapi/visitor.h"
 364 #include "qapi/qmp/qerror.h"
 365 #include "%(prefix)sqapi-types.h"
 366
 367 ''',
 368                   prefix=prefix))
 369
 370 schema = QAPISchema(input_file)
 371 gen = QAPISchemaGenVisitVisitor()
 372 schema.visit(gen)
 373 fdef.write(gen.defn)
 374 fdecl.write(gen.decl)
 375
 376 close_output(fdef, fdecl)