scripts/qapi-types.py

   1 #
   2 # QAPI types generator
   3 #
   4 # Copyright IBM, Corp. 2011
   5 # Copyright (c) 2013-2016 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 # variants must be emitted before their container; track what has already
  18 # been output
  19 objects_seen = set()
  20
  21
  22 def gen_fwd_object_or_array(name):
  23     return mcgen('''
  24
  25 typedef struct %(c_name)s %(c_name)s;
  26 ''',
  27                  c_name=c_name(name))
  28
  29
  30 def gen_array(name, element_type):
  31     return mcgen('''
  32
  33 struct %(c_name)s {
  34     %(c_name)s *next;
  35     %(c_type)s value;
  36 };
  37 ''',
  38                  c_name=c_name(name), c_type=element_type.c_type())
  39
  40
  41 def gen_struct_members(members):
  42     ret = ''
  43     for memb in members:
  44         if memb.optional:
  45             ret += mcgen('''
  46     bool has_%(c_name)s;
  47 ''',
  48                          c_name=c_name(memb.name))
  49         ret += mcgen('''
  50     %(c_type)s %(c_name)s;
  51 ''',
  52                      c_type=memb.type.c_type(), c_name=c_name(memb.name))
  53     return ret
  54
  55
  56 def gen_object(name, base, members, variants):
  57     if name in objects_seen:
  58         return ''
  59     objects_seen.add(name)
  60
  61     ret = ''
  62     if variants:
  63         for v in variants.variants:
  64             if isinstance(v.type, QAPISchemaObjectType):
  65                 ret += gen_object(v.type.name, v.type.base,
  66                                   v.type.local_members, v.type.variants)
  67
  68     ret += mcgen('''
  69
  70 struct %(c_name)s {
  71 ''',
  72                  c_name=c_name(name))
  73
  74     if base:
  75         if not base.is_implicit():
  76             ret += mcgen('''
  77     /* Members inherited from %(c_name)s: */
  78 ''',
  79                          c_name=base.c_name())
  80         ret += gen_struct_members(base.members)
  81         if not base.is_implicit():
  82             ret += mcgen('''
  83     /* Own members: */
  84 ''')
  85     ret += gen_struct_members(members)
  86
  87     if variants:
  88         ret += gen_variants(variants)
  89
  90     # Make sure that all structs have at least one member; this avoids
  91     # potential issues with attempting to malloc space for zero-length
  92     # structs in C, and also incompatibility with C++ (where an empty
  93     # struct is size 1).
  94     if not (base and base.members) and not members and not variants:
  95         ret += mcgen('''
  96     char qapi_dummy_for_empty_struct;
  97 ''')
  98
  99     ret += mcgen('''
 100 };
 101 ''')
 102
 103     return ret
 104
 105
 106 def gen_upcast(name, base):
 107     # C makes const-correctness ugly.  We have to cast away const to let
 108     # this function work for both const and non-const obj.
 109     return mcgen('''
 110
 111 static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
 112 {
 113     return (%(base)s *)obj;
 114 }
 115 ''',
 116                  c_name=c_name(name), base=base.c_name())
 117
 118
 119 def gen_variants(variants):
 120     ret = mcgen('''
 121     union { /* union tag is @%(c_name)s */
 122 ''',
 123                 c_name=c_name(variants.tag_member.name))
 124
 125     for var in variants.variants:
 126         ret += mcgen('''
 127         %(c_type)s %(c_name)s;
 128 ''',
 129                      c_type=var.type.c_unboxed_type(),
 130                      c_name=c_name(var.name))
 131
 132     ret += mcgen('''
 133     } u;
 134 ''')
 135
 136     return ret
 137
 138
 139 def gen_type_cleanup_decl(name):
 140     ret = mcgen('''
 141
 142 void qapi_free_%(c_name)s(%(c_name)s *obj);
 143 ''',
 144                 c_name=c_name(name))
 145     return ret
 146
 147
 148 def gen_type_cleanup(name):
 149     ret = mcgen('''
 150
 151 void qapi_free_%(c_name)s(%(c_name)s *obj)
 152 {
 153     Visitor *v;
 154
 155     if (!obj) {
 156         return;
 157     }
 158
 159     v = qapi_dealloc_visitor_new();
 160     visit_type_%(c_name)s(v, NULL, &obj, NULL);
 161     visit_free(v);
 162 }
 163 ''',
 164                 c_name=c_name(name))
 165     return ret
 166
 167
 168 class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
 169     def __init__(self):
 170         self.decl = None
 171         self.defn = None
 172         self._fwdecl = None
 173         self._btin = None
 174
 175     def visit_begin(self, schema):
 176         # gen_object() is recursive, ensure it doesn't visit the empty type
 177         objects_seen.add(schema.the_empty_object_type.name)
 178         self.decl = ''
 179         self.defn = ''
 180         self._fwdecl = ''
 181         self._btin = guardstart('QAPI_TYPES_BUILTIN')
 182
 183     def visit_end(self):
 184         self.decl = self._fwdecl + self.decl
 185         self._fwdecl = None
 186         # To avoid header dependency hell, we always generate
 187         # declarations for built-in types in our header files and
 188         # simply guard them.  See also do_builtins (command line
 189         # option -b).
 190         self._btin += guardend('QAPI_TYPES_BUILTIN')
 191         self.decl = self._btin + self.decl
 192         self._btin = None
 193
 194     def _gen_type_cleanup(self, name):
 195         self.decl += gen_type_cleanup_decl(name)
 196         self.defn += gen_type_cleanup(name)
 197
 198     def visit_enum_type(self, name, info, values, prefix):
 199         # Special case for our lone builtin enum type
 200         # TODO use something cleaner than existence of info
 201         if not info:
 202             self._btin += gen_enum(name, values, prefix)
 203             if do_builtins:
 204                 self.defn += gen_enum_lookup(name, values, prefix)
 205         else:
 206             self._fwdecl += gen_enum(name, values, prefix)
 207             self.defn += gen_enum_lookup(name, values, prefix)
 208
 209     def visit_array_type(self, name, info, element_type):
 210         if isinstance(element_type, QAPISchemaBuiltinType):
 211             self._btin += gen_fwd_object_or_array(name)
 212             self._btin += gen_array(name, element_type)
 213             self._btin += gen_type_cleanup_decl(name)
 214             if do_builtins:
 215                 self.defn += gen_type_cleanup(name)
 216         else:
 217             self._fwdecl += gen_fwd_object_or_array(name)
 218             self.decl += gen_array(name, element_type)
 219             self._gen_type_cleanup(name)
 220
 221     def visit_object_type(self, name, info, base, members, variants):
 222         # Nothing to do for the special empty builtin
 223         if name == 'q_empty':
 224             return
 225         self._fwdecl += gen_fwd_object_or_array(name)
 226         self.decl += gen_object(name, base, members, variants)
 227         if base and not base.is_implicit():
 228             self.decl += gen_upcast(name, base)
 229         # TODO Worth changing the visitor signature, so we could
 230         # directly use rather than repeat type.is_implicit()?
 231         if not name.startswith('q_'):
 232             # implicit types won't be directly allocated/freed
 233             self._gen_type_cleanup(name)
 234
 235     def visit_alternate_type(self, name, info, variants):
 236         self._fwdecl += gen_fwd_object_or_array(name)
 237         self.decl += gen_object(name, None, [variants.tag_member], variants)
 238         self._gen_type_cleanup(name)
 239
 240 # If you link code generated from multiple schemata, you want only one
 241 # instance of the code for built-in types.  Generate it only when
 242 # do_builtins, enabled by command line option -b.  See also
 243 # QAPISchemaGenTypeVisitor.visit_end().
 244 do_builtins = False
 245
 246 (input_file, output_dir, do_c, do_h, prefix, opts) = \
 247     parse_command_line("b", ["builtins"])
 248
 249 for o, a in opts:
 250     if o in ("-b", "--builtins"):
 251         do_builtins = True
 252
 253 c_comment = '''
 254 /*
 255  * deallocation functions for schema-defined QAPI types
 256  *
 257  * Copyright IBM, Corp. 2011
 258  *
 259  * Authors:
 260  *  Anthony Liguori   <aliguori@us.ibm.com>
 261  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
 262  *
 263  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 264  * See the COPYING.LIB file in the top-level directory.
 265  *
 266  */
 267 '''
 268 h_comment = '''
 269 /*
 270  * schema-defined QAPI types
 271  *
 272  * Copyright IBM, Corp. 2011
 273  *
 274  * Authors:
 275  *  Anthony Liguori   <aliguori@us.ibm.com>
 276  *
 277  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 278  * See the COPYING.LIB file in the top-level directory.
 279  *
 280  */
 281 '''
 282
 283 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
 284                             'qapi-types.c', 'qapi-types.h',
 285                             c_comment, h_comment)
 286
 287 fdef.write(mcgen('''
 288 #include "qemu/osdep.h"
 289 #include "qapi/dealloc-visitor.h"
 290 #include "%(prefix)sqapi-types.h"
 291 #include "%(prefix)sqapi-visit.h"
 292 ''',
 293                  prefix=prefix))
 294
 295 schema = QAPISchema(input_file)
 296 gen = QAPISchemaGenTypeVisitor()
 297 schema.visit(gen)
 298 fdef.write(gen.defn)
 299 fdecl.write(gen.decl)
 300
 301 close_output(fdef, fdecl)