scripts/qapi/types.py

   1 """
   2 QAPI types generator
   3
   4 Copyright IBM, Corp. 2011
   5 Copyright (c) 2013-2018 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
  16 from qapi.common import *
  17 from qapi.gen import QAPISchemaModularCVisitor, ifcontext
  18 from qapi.schema import QAPISchemaEnumMember, QAPISchemaObjectType
  19
  20
  21 # variants must be emitted before their container; track what has already
  22 # been output
  23 objects_seen = set()
  24
  25
  26 def gen_enum_lookup(name, members, prefix=None):
  27     ret = mcgen('''
  28
  29 const QEnumLookup %(c_name)s_lookup = {
  30     .array = (const char *const[]) {
  31 ''',
  32                 c_name=c_name(name))
  33     for m in members:
  34         ret += gen_if(m.ifcond)
  35         index = c_enum_const(name, m.name, prefix)
  36         ret += mcgen('''
  37         [%(index)s] = "%(name)s",
  38 ''',
  39                      index=index, name=m.name)
  40         ret += gen_endif(m.ifcond)
  41
  42     ret += mcgen('''
  43     },
  44     .size = %(max_index)s
  45 };
  46 ''',
  47                  max_index=c_enum_const(name, '_MAX', prefix))
  48     return ret
  49
  50
  51 def gen_enum(name, members, prefix=None):
  52     # append automatically generated _MAX value
  53     enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
  54
  55     ret = mcgen('''
  56
  57 typedef enum %(c_name)s {
  58 ''',
  59                 c_name=c_name(name))
  60
  61     for m in enum_members:
  62         ret += gen_if(m.ifcond)
  63         ret += mcgen('''
  64     %(c_enum)s,
  65 ''',
  66                      c_enum=c_enum_const(name, m.name, prefix))
  67         ret += gen_endif(m.ifcond)
  68
  69     ret += mcgen('''
  70 } %(c_name)s;
  71 ''',
  72                  c_name=c_name(name))
  73
  74     ret += mcgen('''
  75
  76 #define %(c_name)s_str(val) \\
  77     qapi_enum_lookup(&%(c_name)s_lookup, (val))
  78
  79 extern const QEnumLookup %(c_name)s_lookup;
  80 ''',
  81                  c_name=c_name(name))
  82     return ret
  83
  84
  85 def gen_fwd_object_or_array(name):
  86     return mcgen('''
  87
  88 typedef struct %(c_name)s %(c_name)s;
  89 ''',
  90                  c_name=c_name(name))
  91
  92
  93 def gen_array(name, element_type):
  94     return mcgen('''
  95
  96 struct %(c_name)s {
  97     %(c_name)s *next;
  98     %(c_type)s value;
  99 };
 100 ''',
 101                  c_name=c_name(name), c_type=element_type.c_type())
 102
 103
 104 def gen_struct_members(members):
 105     ret = ''
 106     for memb in members:
 107         ret += gen_if(memb.ifcond)
 108         if memb.optional:
 109             ret += mcgen('''
 110     bool has_%(c_name)s;
 111 ''',
 112                          c_name=c_name(memb.name))
 113         ret += mcgen('''
 114     %(c_type)s %(c_name)s;
 115 ''',
 116                      c_type=memb.type.c_type(), c_name=c_name(memb.name))
 117         ret += gen_endif(memb.ifcond)
 118     return ret
 119
 120
 121 def gen_object(name, ifcond, base, members, variants):
 122     if name in objects_seen:
 123         return ''
 124     objects_seen.add(name)
 125
 126     ret = ''
 127     if variants:
 128         for v in variants.variants:
 129             if isinstance(v.type, QAPISchemaObjectType):
 130                 ret += gen_object(v.type.name, v.type.ifcond, v.type.base,
 131                                   v.type.local_members, v.type.variants)
 132
 133     ret += mcgen('''
 134
 135 ''')
 136     ret += gen_if(ifcond)
 137     ret += mcgen('''
 138 struct %(c_name)s {
 139 ''',
 140                  c_name=c_name(name))
 141
 142     if base:
 143         if not base.is_implicit():
 144             ret += mcgen('''
 145     /* Members inherited from %(c_name)s: */
 146 ''',
 147                          c_name=base.c_name())
 148         ret += gen_struct_members(base.members)
 149         if not base.is_implicit():
 150             ret += mcgen('''
 151     /* Own members: */
 152 ''')
 153     ret += gen_struct_members(members)
 154
 155     if variants:
 156         ret += gen_variants(variants)
 157
 158     # Make sure that all structs have at least one member; this avoids
 159     # potential issues with attempting to malloc space for zero-length
 160     # structs in C, and also incompatibility with C++ (where an empty
 161     # struct is size 1).
 162     if (not base or base.is_empty()) and not members and not variants:
 163         ret += mcgen('''
 164     char qapi_dummy_for_empty_struct;
 165 ''')
 166
 167     ret += mcgen('''
 168 };
 169 ''')
 170     ret += gen_endif(ifcond)
 171
 172     return ret
 173
 174
 175 def gen_upcast(name, base):
 176     # C makes const-correctness ugly.  We have to cast away const to let
 177     # this function work for both const and non-const obj.
 178     return mcgen('''
 179
 180 static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
 181 {
 182     return (%(base)s *)obj;
 183 }
 184 ''',
 185                  c_name=c_name(name), base=base.c_name())
 186
 187
 188 def gen_variants(variants):
 189     ret = mcgen('''
 190     union { /* union tag is @%(c_name)s */
 191 ''',
 192                 c_name=c_name(variants.tag_member.name))
 193
 194     for var in variants.variants:
 195         if var.type.name == 'q_empty':
 196             continue
 197         ret += gen_if(var.ifcond)
 198         ret += mcgen('''
 199         %(c_type)s %(c_name)s;
 200 ''',
 201                      c_type=var.type.c_unboxed_type(),
 202                      c_name=c_name(var.name))
 203         ret += gen_endif(var.ifcond)
 204
 205     ret += mcgen('''
 206     } u;
 207 ''')
 208
 209     return ret
 210
 211
 212 def gen_type_cleanup_decl(name):
 213     ret = mcgen('''
 214
 215 void qapi_free_%(c_name)s(%(c_name)s *obj);
 216 ''',
 217                 c_name=c_name(name))
 218     return ret
 219
 220
 221 def gen_type_cleanup(name):
 222     ret = mcgen('''
 223
 224 void qapi_free_%(c_name)s(%(c_name)s *obj)
 225 {
 226     Visitor *v;
 227
 228     if (!obj) {
 229         return;
 230     }
 231
 232     v = qapi_dealloc_visitor_new();
 233     visit_type_%(c_name)s(v, NULL, &obj, NULL);
 234     visit_free(v);
 235 }
 236 ''',
 237                 c_name=c_name(name))
 238     return ret
 239
 240
 241 class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
 242
 243     def __init__(self, prefix):
 244         super().__init__(
 245             prefix, 'qapi-types', ' * Schema-defined QAPI types',
 246             ' * Built-in QAPI types', __doc__)
 247
 248     def _begin_system_module(self, name):
 249         self._genc.preamble_add(mcgen('''
 250 #include "qemu/osdep.h"
 251 #include "qapi/dealloc-visitor.h"
 252 #include "qapi/qapi-builtin-types.h"
 253 #include "qapi/qapi-builtin-visit.h"
 254 '''))
 255         self._genh.preamble_add(mcgen('''
 256 #include "qapi/util.h"
 257 '''))
 258
 259     def _begin_user_module(self, name):
 260         types = self._module_basename('qapi-types', name)
 261         visit = self._module_basename('qapi-visit', name)
 262         self._genc.preamble_add(mcgen('''
 263 #include "qemu/osdep.h"
 264 #include "qapi/dealloc-visitor.h"
 265 #include "%(types)s.h"
 266 #include "%(visit)s.h"
 267 ''',
 268                                       types=types, visit=visit))
 269         self._genh.preamble_add(mcgen('''
 270 #include "qapi/qapi-builtin-types.h"
 271 '''))
 272
 273     def visit_begin(self, schema):
 274         # gen_object() is recursive, ensure it doesn't visit the empty type
 275         objects_seen.add(schema.the_empty_object_type.name)
 276
 277     def _gen_type_cleanup(self, name):
 278         self._genh.add(gen_type_cleanup_decl(name))
 279         self._genc.add(gen_type_cleanup(name))
 280
 281     def visit_enum_type(self, name, info, ifcond, features, members, prefix):
 282         with ifcontext(ifcond, self._genh, self._genc):
 283             self._genh.preamble_add(gen_enum(name, members, prefix))
 284             self._genc.add(gen_enum_lookup(name, members, prefix))
 285
 286     def visit_array_type(self, name, info, ifcond, element_type):
 287         with ifcontext(ifcond, self._genh, self._genc):
 288             self._genh.preamble_add(gen_fwd_object_or_array(name))
 289             self._genh.add(gen_array(name, element_type))
 290             self._gen_type_cleanup(name)
 291
 292     def visit_object_type(self, name, info, ifcond, features,
 293                           base, members, variants):
 294         # Nothing to do for the special empty builtin
 295         if name == 'q_empty':
 296             return
 297         with ifcontext(ifcond, self._genh):
 298             self._genh.preamble_add(gen_fwd_object_or_array(name))
 299         self._genh.add(gen_object(name, ifcond, base, members, variants))
 300         with ifcontext(ifcond, self._genh, self._genc):
 301             if base and not base.is_implicit():
 302                 self._genh.add(gen_upcast(name, base))
 303             # TODO Worth changing the visitor signature, so we could
 304             # directly use rather than repeat type.is_implicit()?
 305             if not name.startswith('q_'):
 306                 # implicit types won't be directly allocated/freed
 307                 self._gen_type_cleanup(name)
 308
 309     def visit_alternate_type(self, name, info, ifcond, features, variants):
 310         with ifcontext(ifcond, self._genh):
 311             self._genh.preamble_add(gen_fwd_object_or_array(name))
 312         self._genh.add(gen_object(name, ifcond, None,
 313                                   [variants.tag_member], variants))
 314         with ifcontext(ifcond, self._genh, self._genc):
 315             self._gen_type_cleanup(name)
 316
 317
 318 def gen_types(schema, output_dir, prefix, opt_builtins):
 319     vis = QAPISchemaGenTypeVisitor(prefix)
 320     schema.visit(vis)
 321     vis.write(output_dir, opt_builtins)