scripts/qapi-types.py

   1 #
   2 # QAPI types generator
   3 #
   4 # Copyright IBM, Corp. 2011
   5 # Copyright (c) 2013-2015 Red Hat Inc.
   6 #
   7 # Authors:
   8 #  Anthony Liguori <aliguori@us.ibm.com>
   9 #  Markus Armbruster <armbru@redhat.com>
  10 #
  11 # This work is licensed under the terms of the GNU GPL, version 2.
  12 # See the COPYING file in the top-level directory.
  13
  14 from qapi import *
  15
  16
  17 def gen_fwd_object_or_array(name):
  18     return mcgen('''
  19
  20 typedef struct %(c_name)s %(c_name)s;
  21 ''',
  22                  c_name=c_name(name))
  23
  24
  25 def gen_array(name, element_type):
  26     return mcgen('''
  27
  28 struct %(c_name)s {
  29     union {
  30         %(c_type)s value;
  31         uint64_t padding;
  32     };
  33     %(c_name)s *next;
  34 };
  35 ''',
  36                  c_name=c_name(name), c_type=element_type.c_type())
  37
  38
  39 def gen_struct_field(name, typ, optional):
  40     ret = ''
  41
  42     if optional:
  43         ret += mcgen('''
  44     bool has_%(c_name)s;
  45 ''',
  46                      c_name=c_name(name))
  47     ret += mcgen('''
  48     %(c_type)s %(c_name)s;
  49 ''',
  50                  c_type=typ.c_type(), c_name=c_name(name))
  51     return ret
  52
  53
  54 def gen_struct_fields(local_members, base=None):
  55     ret = ''
  56
  57     if base:
  58         ret += mcgen('''
  59     /* Members inherited from %(c_name)s: */
  60 ''',
  61                      c_name=base.c_name())
  62         for memb in base.members:
  63             ret += gen_struct_field(memb.name, memb.type, memb.optional)
  64         ret += mcgen('''
  65     /* Own members: */
  66 ''')
  67
  68     for memb in local_members:
  69         ret += gen_struct_field(memb.name, memb.type, memb.optional)
  70     return ret
  71
  72
  73 def gen_struct(name, base, members):
  74     ret = mcgen('''
  75
  76 struct %(c_name)s {
  77 ''',
  78                 c_name=c_name(name))
  79
  80     if base:
  81         ret += gen_struct_field('base', base, False)
  82
  83     ret += gen_struct_fields(members)
  84
  85     # Make sure that all structs have at least one field; this avoids
  86     # potential issues with attempting to malloc space for zero-length
  87     # structs in C, and also incompatibility with C++ (where an empty
  88     # struct is size 1).
  89     if not base and not members:
  90         ret += mcgen('''
  91     char qapi_dummy_field_for_empty_struct;
  92 ''')
  93
  94     ret += mcgen('''
  95 };
  96 ''')
  97
  98     return ret
  99
 100
 101 def gen_alternate_qtypes_decl(name):
 102     return mcgen('''
 103
 104 extern const int %(c_name)s_qtypes[];
 105 ''',
 106                  c_name=c_name(name))
 107
 108
 109 def gen_alternate_qtypes(name, variants):
 110     ret = mcgen('''
 111
 112 const int %(c_name)s_qtypes[QTYPE_MAX] = {
 113 ''',
 114                 c_name=c_name(name))
 115
 116     for var in variants.variants:
 117         qtype = var.type.alternate_qtype()
 118         assert qtype
 119
 120         ret += mcgen('''
 121     [%(qtype)s] = %(enum_const)s,
 122 ''',
 123                      qtype=qtype,
 124                      enum_const=c_enum_const(variants.tag_member.type.name,
 125                                              var.name))
 126
 127     ret += mcgen('''
 128 };
 129 ''')
 130     return ret
 131
 132
 133 def gen_union(name, base, variants):
 134     ret = mcgen('''
 135
 136 struct %(c_name)s {
 137 ''',
 138                 c_name=c_name(name))
 139     if base:
 140         ret += gen_struct_fields([], base)
 141     else:
 142         ret += mcgen('''
 143     %(c_type)s kind;
 144 ''',
 145                      c_type=c_name(variants.tag_member.type.name))
 146
 147     # FIXME: What purpose does data serve, besides preventing a union that
 148     # has a branch named 'data'? We use it in qapi-visit.py to decide
 149     # whether to bypass the switch statement if visiting the discriminator
 150     # failed; but since we 0-initialize structs, and cannot tell what
 151     # branch of the union is in use if the discriminator is invalid, there
 152     # should not be any data leaks even without a data pointer.  Or, if
 153     # 'data' is merely added to guarantee we don't have an empty union,
 154     # shouldn't we enforce that at .json parse time?
 155     ret += mcgen('''
 156     union { /* union tag is @%(c_name)s */
 157         void *data;
 158 ''',
 159                  # TODO ugly special case for simple union
 160                  # Use same tag name in C as on the wire to get rid of
 161                  # it, then: c_name=c_name(variants.tag_member.name)
 162                  c_name=c_name(variants.tag_name or 'kind'))
 163
 164     for var in variants.variants:
 165         # Ugly special case for simple union TODO get rid of it
 166         typ = var.simple_union_type() or var.type
 167         ret += mcgen('''
 168         %(c_type)s %(c_name)s;
 169 ''',
 170                      c_type=typ.c_type(),
 171                      c_name=c_name(var.name))
 172
 173     ret += mcgen('''
 174     };
 175 };
 176 ''')
 177
 178     return ret
 179
 180
 181 def gen_type_cleanup_decl(name):
 182     ret = mcgen('''
 183
 184 void qapi_free_%(c_name)s(%(c_name)s *obj);
 185 ''',
 186                 c_name=c_name(name))
 187     return ret
 188
 189
 190 def gen_type_cleanup(name):
 191     ret = mcgen('''
 192
 193 void qapi_free_%(c_name)s(%(c_name)s *obj)
 194 {
 195     QapiDeallocVisitor *qdv;
 196     Visitor *v;
 197
 198     if (!obj) {
 199         return;
 200     }
 201
 202     qdv = qapi_dealloc_visitor_new();
 203     v = qapi_dealloc_get_visitor(qdv);
 204     visit_type_%(c_name)s(v, &obj, NULL, NULL);
 205     qapi_dealloc_visitor_cleanup(qdv);
 206 }
 207 ''',
 208                 c_name=c_name(name))
 209     return ret
 210
 211
 212 class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
 213     def __init__(self):
 214         self.decl = None
 215         self.defn = None
 216         self._fwdecl = None
 217         self._fwdefn = None
 218         self._btin = None
 219
 220     def visit_begin(self, schema):
 221         self.decl = ''
 222         self.defn = ''
 223         self._fwdecl = ''
 224         self._fwdefn = ''
 225         self._btin = guardstart('QAPI_TYPES_BUILTIN')
 226
 227     def visit_end(self):
 228         self.decl = self._fwdecl + self.decl
 229         self._fwdecl = None
 230         self.defn = self._fwdefn + self.defn
 231         self._fwdefn = None
 232         # To avoid header dependency hell, we always generate
 233         # declarations for built-in types in our header files and
 234         # simply guard them.  See also do_builtins (command line
 235         # option -b).
 236         self._btin += guardend('QAPI_TYPES_BUILTIN')
 237         self.decl = self._btin + self.decl
 238         self._btin = None
 239
 240     def visit_needed(self, entity):
 241         # Visit everything except implicit objects
 242         return not (entity.is_implicit() and
 243                     isinstance(entity, QAPISchemaObjectType))
 244
 245     def _gen_type_cleanup(self, name):
 246         self.decl += gen_type_cleanup_decl(name)
 247         self.defn += gen_type_cleanup(name)
 248
 249     def visit_enum_type(self, name, info, values, prefix):
 250         self._fwdecl += gen_enum(name, values, prefix)
 251         self._fwdefn += gen_enum_lookup(name, values, prefix)
 252
 253     def visit_array_type(self, name, info, element_type):
 254         if isinstance(element_type, QAPISchemaBuiltinType):
 255             self._btin += gen_fwd_object_or_array(name)
 256             self._btin += gen_array(name, element_type)
 257             self._btin += gen_type_cleanup_decl(name)
 258             if do_builtins:
 259                 self.defn += gen_type_cleanup(name)
 260         else:
 261             self._fwdecl += gen_fwd_object_or_array(name)
 262             self.decl += gen_array(name, element_type)
 263             self._gen_type_cleanup(name)
 264
 265     def visit_object_type(self, name, info, base, members, variants):
 266         self._fwdecl += gen_fwd_object_or_array(name)
 267         if variants:
 268             assert not members      # not implemented
 269             self.decl += gen_union(name, base, variants)
 270         else:
 271             self.decl += gen_struct(name, base, members)
 272         self._gen_type_cleanup(name)
 273
 274     def visit_alternate_type(self, name, info, variants):
 275         self._fwdecl += gen_fwd_object_or_array(name)
 276         self._fwdefn += gen_alternate_qtypes(name, variants)
 277         self.decl += gen_union(name, None, variants)
 278         self.decl += gen_alternate_qtypes_decl(name)
 279         self._gen_type_cleanup(name)
 280
 281 # If you link code generated from multiple schemata, you want only one
 282 # instance of the code for built-in types.  Generate it only when
 283 # do_builtins, enabled by command line option -b.  See also
 284 # QAPISchemaGenTypeVisitor.visit_end().
 285 do_builtins = False
 286
 287 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 288     parse_command_line("b", ["builtins"])
 289
 290 for o, a in opts:
 291     if o in ("-b", "--builtins"):
 292         do_builtins = True
 293
 294 c_comment = '''
 295 /*
 296  * deallocation functions for schema-defined QAPI types
 297  *
 298  * Copyright IBM, Corp. 2011
 299  *
 300  * Authors:
 301  *  Anthony Liguori   <aliguori@us.ibm.com>
 302  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
 303  *
 304  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 305  * See the COPYING.LIB file in the top-level directory.
 306  *
 307  */
 308 '''
 309 h_comment = '''
 310 /*
 311  * schema-defined QAPI types
 312  *
 313  * Copyright IBM, Corp. 2011
 314  *
 315  * Authors:
 316  *  Anthony Liguori   <aliguori@us.ibm.com>
 317  *
 318  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 319  * See the COPYING.LIB file in the top-level directory.
 320  *
 321  */
 322 '''
 323
 324 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 325                             'qapi-types.c', 'qapi-types.h',
 326                             c_comment, h_comment)
 327
 328 fdef.write(mcgen('''
 329 #include "qapi/dealloc-visitor.h"
 330 #include "%(prefix)sqapi-types.h"
 331 #include "%(prefix)sqapi-visit.h"
 332 ''',
 333                  prefix=prefix))
 334
 335 fdecl.write(mcgen('''
 336 #include <stdbool.h>
 337 #include <stdint.h>
 338 #include "qapi/qmp/qobject.h"
 339 '''))
 340
 341 schema = QAPISchema(input_file)
 342 gen = QAPISchemaGenTypeVisitor()
 343 schema.visit(gen)
 344 fdef.write(gen.defn)
 345 fdecl.write(gen.decl)
 346
 347 close_output(fdef, fdecl)