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