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     ret += gen_struct_fields(members, base)
  81
  82     # Make sure that all structs have at least one field; this avoids
  83     # potential issues with attempting to malloc space for zero-length
  84     # structs in C, and also incompatibility with C++ (where an empty
  85     # struct is size 1).
  86     if not (base and base.members) and not members:
  87         ret += mcgen('''
  88     char qapi_dummy_field_for_empty_struct;
  89 ''')
  90
  91     ret += mcgen('''
  92 };
  93 ''')
  94
  95     return ret
  96
  97
  98 def gen_upcast(name, base):
  99     # C makes const-correctness ugly.  We have to cast away const to let
 100     # this function work for both const and non-const obj.
 101     return mcgen('''
 102
 103 static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
 104 {
 105     return (%(base)s *)obj;
 106 }
 107 ''',
 108                  c_name=c_name(name), base=base.c_name())
 109
 110
 111 def gen_alternate_qtypes_decl(name):
 112     return mcgen('''
 113
 114 extern const int %(c_name)s_qtypes[];
 115 ''',
 116                  c_name=c_name(name))
 117
 118
 119 def gen_alternate_qtypes(name, variants):
 120     ret = mcgen('''
 121
 122 const int %(c_name)s_qtypes[QTYPE_MAX] = {
 123 ''',
 124                 c_name=c_name(name))
 125
 126     for var in variants.variants:
 127         qtype = var.type.alternate_qtype()
 128         assert qtype
 129
 130         ret += mcgen('''
 131     [%(qtype)s] = %(enum_const)s,
 132 ''',
 133                      qtype=qtype,
 134                      enum_const=c_enum_const(variants.tag_member.type.name,
 135                                              var.name))
 136
 137     ret += mcgen('''
 138 };
 139 ''')
 140     return ret
 141
 142
 143 def gen_union(name, base, variants):
 144     ret = mcgen('''
 145
 146 struct %(c_name)s {
 147 ''',
 148                 c_name=c_name(name))
 149     if base:
 150         ret += gen_struct_fields([], base)
 151     else:
 152         ret += gen_struct_field(variants.tag_member.name,
 153                                 variants.tag_member.type,
 154                                 False)
 155
 156     # FIXME: What purpose does data serve, besides preventing a union that
 157     # has a branch named 'data'? We use it in qapi-visit.py to decide
 158     # whether to bypass the switch statement if visiting the discriminator
 159     # failed; but since we 0-initialize structs, and cannot tell what
 160     # branch of the union is in use if the discriminator is invalid, there
 161     # should not be any data leaks even without a data pointer.  Or, if
 162     # 'data' is merely added to guarantee we don't have an empty union,
 163     # shouldn't we enforce that at .json parse time?
 164     ret += mcgen('''
 165     union { /* union tag is @%(c_name)s */
 166         void *data;
 167 ''',
 168                  c_name=c_name(variants.tag_member.name))
 169
 170     for var in variants.variants:
 171         # Ugly special case for simple union TODO get rid of it
 172         typ = var.simple_union_type() or var.type
 173         ret += mcgen('''
 174         %(c_type)s %(c_name)s;
 175 ''',
 176                      c_type=typ.c_type(),
 177                      c_name=c_name(var.name))
 178
 179     ret += mcgen('''
 180     } u;
 181 };
 182 ''')
 183
 184     return ret
 185
 186
 187 def gen_type_cleanup_decl(name):
 188     ret = mcgen('''
 189
 190 void qapi_free_%(c_name)s(%(c_name)s *obj);
 191 ''',
 192                 c_name=c_name(name))
 193     return ret
 194
 195
 196 def gen_type_cleanup(name):
 197     ret = mcgen('''
 198
 199 void qapi_free_%(c_name)s(%(c_name)s *obj)
 200 {
 201     QapiDeallocVisitor *qdv;
 202     Visitor *v;
 203
 204     if (!obj) {
 205         return;
 206     }
 207
 208     qdv = qapi_dealloc_visitor_new();
 209     v = qapi_dealloc_get_visitor(qdv);
 210     visit_type_%(c_name)s(v, &obj, NULL, NULL);
 211     qapi_dealloc_visitor_cleanup(qdv);
 212 }
 213 ''',
 214                 c_name=c_name(name))
 215     return ret
 216
 217
 218 class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
 219     def __init__(self):
 220         self.decl = None
 221         self.defn = None
 222         self._fwdecl = None
 223         self._fwdefn = None
 224         self._btin = None
 225
 226     def visit_begin(self, schema):
 227         self.decl = ''
 228         self.defn = ''
 229         self._fwdecl = ''
 230         self._fwdefn = ''
 231         self._btin = guardstart('QAPI_TYPES_BUILTIN')
 232
 233     def visit_end(self):
 234         self.decl = self._fwdecl + self.decl
 235         self._fwdecl = None
 236         self.defn = self._fwdefn + self.defn
 237         self._fwdefn = None
 238         # To avoid header dependency hell, we always generate
 239         # declarations for built-in types in our header files and
 240         # simply guard them.  See also do_builtins (command line
 241         # option -b).
 242         self._btin += guardend('QAPI_TYPES_BUILTIN')
 243         self.decl = self._btin + self.decl
 244         self._btin = None
 245
 246     def visit_needed(self, entity):
 247         # Visit everything except implicit objects
 248         return not (entity.is_implicit() and
 249                     isinstance(entity, QAPISchemaObjectType))
 250
 251     def _gen_type_cleanup(self, name):
 252         self.decl += gen_type_cleanup_decl(name)
 253         self.defn += gen_type_cleanup(name)
 254
 255     def visit_enum_type(self, name, info, values, prefix):
 256         self._fwdecl += gen_enum(name, values, prefix)
 257         self._fwdefn += gen_enum_lookup(name, values, prefix)
 258
 259     def visit_array_type(self, name, info, element_type):
 260         if isinstance(element_type, QAPISchemaBuiltinType):
 261             self._btin += gen_fwd_object_or_array(name)
 262             self._btin += gen_array(name, element_type)
 263             self._btin += gen_type_cleanup_decl(name)
 264             if do_builtins:
 265                 self.defn += gen_type_cleanup(name)
 266         else:
 267             self._fwdecl += gen_fwd_object_or_array(name)
 268             self.decl += gen_array(name, element_type)
 269             self._gen_type_cleanup(name)
 270
 271     def visit_object_type(self, name, info, base, members, variants):
 272         self._fwdecl += gen_fwd_object_or_array(name)
 273         if variants:
 274             assert not members      # not implemented
 275             self.decl += gen_union(name, base, variants)
 276         else:
 277             self.decl += gen_struct(name, base, members)
 278         if base:
 279             self.decl += gen_upcast(name, base)
 280         self._gen_type_cleanup(name)
 281
 282     def visit_alternate_type(self, name, info, variants):
 283         self._fwdecl += gen_fwd_object_or_array(name)
 284         self._fwdefn += gen_alternate_qtypes(name, variants)
 285         self.decl += gen_union(name, None, variants)
 286         self.decl += gen_alternate_qtypes_decl(name)
 287         self._gen_type_cleanup(name)
 288
 289 # If you link code generated from multiple schemata, you want only one
 290 # instance of the code for built-in types.  Generate it only when
 291 # do_builtins, enabled by command line option -b.  See also
 292 # QAPISchemaGenTypeVisitor.visit_end().
 293 do_builtins = False
 294
 295 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 296     parse_command_line("b", ["builtins"])
 297
 298 for o, a in opts:
 299     if o in ("-b", "--builtins"):
 300         do_builtins = True
 301
 302 c_comment = '''
 303 /*
 304  * deallocation functions for schema-defined QAPI types
 305  *
 306  * Copyright IBM, Corp. 2011
 307  *
 308  * Authors:
 309  *  Anthony Liguori   <aliguori@us.ibm.com>
 310  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
 311  *
 312  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 313  * See the COPYING.LIB file in the top-level directory.
 314  *
 315  */
 316 '''
 317 h_comment = '''
 318 /*
 319  * schema-defined QAPI types
 320  *
 321  * Copyright IBM, Corp. 2011
 322  *
 323  * Authors:
 324  *  Anthony Liguori   <aliguori@us.ibm.com>
 325  *
 326  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 327  * See the COPYING.LIB file in the top-level directory.
 328  *
 329  */
 330 '''
 331
 332 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 333                             'qapi-types.c', 'qapi-types.h',
 334                             c_comment, h_comment)
 335
 336 fdef.write(mcgen('''
 337 #include "qapi/dealloc-visitor.h"
 338 #include "%(prefix)sqapi-types.h"
 339 #include "%(prefix)sqapi-visit.h"
 340 ''',
 341                  prefix=prefix))
 342
 343 fdecl.write(mcgen('''
 344 #include <stdbool.h>
 345 #include <stdint.h>
 346 #include "qapi/qmp/qobject.h"
 347 '''))
 348
 349 schema = QAPISchema(input_file)
 350 gen = QAPISchemaGenTypeVisitor()
 351 schema.visit(gen)
 352 fdef.write(gen.defn)
 353 fdecl.write(gen.decl)
 354
 355 close_output(fdef, fdecl)