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 typing import List, Optional, Sequence
  17
  18 from .common import (
  19     c_enum_const,
  20     c_name,
  21     gen_endif,
  22     gen_if,
  23     mcgen,
  24 )
  25 from .gen import QAPISchemaModularCVisitor, ifcontext
  26 from .schema import (
  27     QAPISchema,
  28     QAPISchemaEnumMember,
  29     QAPISchemaFeature,
  30     QAPISchemaObjectType,
  31     QAPISchemaObjectTypeMember,
  32     QAPISchemaType,
  33     QAPISchemaVariants,
  34 )
  35 from .source import QAPISourceInfo
  36
  37
  38 # variants must be emitted before their container; track what has already
  39 # been output
  40 objects_seen = set()
  41
  42
  43 def gen_enum_lookup(name: str,
  44                     members: List[QAPISchemaEnumMember],
  45                     prefix: Optional[str] = None) -> str:
  46     ret = mcgen('''
  47
  48 const QEnumLookup %(c_name)s_lookup = {
  49     .array = (const char *const[]) {
  50 ''',
  51                 c_name=c_name(name))
  52     for memb in members:
  53         ret += gen_if(memb.ifcond)
  54         index = c_enum_const(name, memb.name, prefix)
  55         ret += mcgen('''
  56         [%(index)s] = "%(name)s",
  57 ''',
  58                      index=index, name=memb.name)
  59         ret += gen_endif(memb.ifcond)
  60
  61     ret += mcgen('''
  62     },
  63     .size = %(max_index)s
  64 };
  65 ''',
  66                  max_index=c_enum_const(name, '_MAX', prefix))
  67     return ret
  68
  69
  70 def gen_enum(name: str,
  71              members: List[QAPISchemaEnumMember],
  72              prefix: Optional[str] = None) -> str:
  73     # append automatically generated _MAX value
  74     enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
  75
  76     ret = mcgen('''
  77
  78 typedef enum %(c_name)s {
  79 ''',
  80                 c_name=c_name(name))
  81
  82     for memb in enum_members:
  83         ret += gen_if(memb.ifcond)
  84         ret += mcgen('''
  85     %(c_enum)s,
  86 ''',
  87                      c_enum=c_enum_const(name, memb.name, prefix))
  88         ret += gen_endif(memb.ifcond)
  89
  90     ret += mcgen('''
  91 } %(c_name)s;
  92 ''',
  93                  c_name=c_name(name))
  94
  95     ret += mcgen('''
  96
  97 #define %(c_name)s_str(val) \\
  98     qapi_enum_lookup(&%(c_name)s_lookup, (val))
  99
 100 extern const QEnumLookup %(c_name)s_lookup;
 101 ''',
 102                  c_name=c_name(name))
 103     return ret
 104
 105
 106 def gen_fwd_object_or_array(name: str) -> str:
 107     return mcgen('''
 108
 109 typedef struct %(c_name)s %(c_name)s;
 110 ''',
 111                  c_name=c_name(name))
 112
 113
 114 def gen_array(name: str, element_type: QAPISchemaType) -> str:
 115     return mcgen('''
 116
 117 struct %(c_name)s {
 118     %(c_name)s *next;
 119     %(c_type)s value;
 120 };
 121 ''',
 122                  c_name=c_name(name), c_type=element_type.c_type())
 123
 124
 125 def gen_struct_members(members: List[QAPISchemaObjectTypeMember]) -> str:
 126     ret = ''
 127     for memb in members:
 128         ret += gen_if(memb.ifcond)
 129         if memb.optional:
 130             ret += mcgen('''
 131     bool has_%(c_name)s;
 132 ''',
 133                          c_name=c_name(memb.name))
 134         ret += mcgen('''
 135     %(c_type)s %(c_name)s;
 136 ''',
 137                      c_type=memb.type.c_type(), c_name=c_name(memb.name))
 138         ret += gen_endif(memb.ifcond)
 139     return ret
 140
 141
 142 def gen_object(name: str, ifcond: Sequence[str],
 143                base: Optional[QAPISchemaObjectType],
 144                members: List[QAPISchemaObjectTypeMember],
 145                variants: Optional[QAPISchemaVariants]) -> str:
 146     if name in objects_seen:
 147         return ''
 148     objects_seen.add(name)
 149
 150     ret = ''
 151     for var in variants.variants if variants else ():
 152         obj = var.type
 153         if not isinstance(obj, QAPISchemaObjectType):
 154             continue
 155         ret += gen_object(obj.name, obj.ifcond, obj.base,
 156                           obj.local_members, obj.variants)
 157
 158     ret += mcgen('''
 159
 160 ''')
 161     ret += gen_if(ifcond)
 162     ret += mcgen('''
 163 struct %(c_name)s {
 164 ''',
 165                  c_name=c_name(name))
 166
 167     if base:
 168         if not base.is_implicit():
 169             ret += mcgen('''
 170     /* Members inherited from %(c_name)s: */
 171 ''',
 172                          c_name=base.c_name())
 173         ret += gen_struct_members(base.members)
 174         if not base.is_implicit():
 175             ret += mcgen('''
 176     /* Own members: */
 177 ''')
 178     ret += gen_struct_members(members)
 179
 180     if variants:
 181         ret += gen_variants(variants)
 182
 183     # Make sure that all structs have at least one member; this avoids
 184     # potential issues with attempting to malloc space for zero-length
 185     # structs in C, and also incompatibility with C++ (where an empty
 186     # struct is size 1).
 187     if (not base or base.is_empty()) and not members and not variants:
 188         ret += mcgen('''
 189     char qapi_dummy_for_empty_struct;
 190 ''')
 191
 192     ret += mcgen('''
 193 };
 194 ''')
 195     ret += gen_endif(ifcond)
 196
 197     return ret
 198
 199
 200 def gen_upcast(name: str, base: QAPISchemaObjectType) -> str:
 201     # C makes const-correctness ugly.  We have to cast away const to let
 202     # this function work for both const and non-const obj.
 203     return mcgen('''
 204
 205 static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
 206 {
 207     return (%(base)s *)obj;
 208 }
 209 ''',
 210                  c_name=c_name(name), base=base.c_name())
 211
 212
 213 def gen_variants(variants: QAPISchemaVariants) -> str:
 214     ret = mcgen('''
 215     union { /* union tag is @%(c_name)s */
 216 ''',
 217                 c_name=c_name(variants.tag_member.name))
 218
 219     for var in variants.variants:
 220         if var.type.name == 'q_empty':
 221             continue
 222         ret += gen_if(var.ifcond)
 223         ret += mcgen('''
 224         %(c_type)s %(c_name)s;
 225 ''',
 226                      c_type=var.type.c_unboxed_type(),
 227                      c_name=c_name(var.name))
 228         ret += gen_endif(var.ifcond)
 229
 230     ret += mcgen('''
 231     } u;
 232 ''')
 233
 234     return ret
 235
 236
 237 def gen_type_cleanup_decl(name: str) -> str:
 238     ret = mcgen('''
 239
 240 void qapi_free_%(c_name)s(%(c_name)s *obj);
 241 G_DEFINE_AUTOPTR_CLEANUP_FUNC(%(c_name)s, qapi_free_%(c_name)s)
 242 ''',
 243                 c_name=c_name(name))
 244     return ret
 245
 246
 247 def gen_type_cleanup(name: str) -> str:
 248     ret = mcgen('''
 249
 250 void qapi_free_%(c_name)s(%(c_name)s *obj)
 251 {
 252     Visitor *v;
 253
 254     if (!obj) {
 255         return;
 256     }
 257
 258     v = qapi_dealloc_visitor_new();
 259     visit_type_%(c_name)s(v, NULL, &obj, NULL);
 260     visit_free(v);
 261 }
 262 ''',
 263                 c_name=c_name(name))
 264     return ret
 265
 266
 267 class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
 268
 269     def __init__(self, prefix: str):
 270         super().__init__(
 271             prefix, 'qapi-types', ' * Schema-defined QAPI types',
 272             ' * Built-in QAPI types', __doc__)
 273
 274     def _begin_builtin_module(self) -> None:
 275         self._genc.preamble_add(mcgen('''
 276 #include "qemu/osdep.h"
 277 #include "qapi/dealloc-visitor.h"
 278 #include "qapi/qapi-builtin-types.h"
 279 #include "qapi/qapi-builtin-visit.h"
 280 '''))
 281         self._genh.preamble_add(mcgen('''
 282 #include "qapi/util.h"
 283 '''))
 284
 285     def _begin_user_module(self, name: str) -> None:
 286         types = self._module_basename('qapi-types', name)
 287         visit = self._module_basename('qapi-visit', name)
 288         self._genc.preamble_add(mcgen('''
 289 #include "qemu/osdep.h"
 290 #include "qapi/dealloc-visitor.h"
 291 #include "%(types)s.h"
 292 #include "%(visit)s.h"
 293 ''',
 294                                       types=types, visit=visit))
 295         self._genh.preamble_add(mcgen('''
 296 #include "qapi/qapi-builtin-types.h"
 297 '''))
 298
 299     def visit_begin(self, schema: QAPISchema) -> None:
 300         # gen_object() is recursive, ensure it doesn't visit the empty type
 301         objects_seen.add(schema.the_empty_object_type.name)
 302
 303     def _gen_type_cleanup(self, name: str) -> None:
 304         self._genh.add(gen_type_cleanup_decl(name))
 305         self._genc.add(gen_type_cleanup(name))
 306
 307     def visit_enum_type(self,
 308                         name: str,
 309                         info: Optional[QAPISourceInfo],
 310                         ifcond: Sequence[str],
 311                         features: List[QAPISchemaFeature],
 312                         members: List[QAPISchemaEnumMember],
 313                         prefix: Optional[str]) -> None:
 314         with ifcontext(ifcond, self._genh, self._genc):
 315             self._genh.preamble_add(gen_enum(name, members, prefix))
 316             self._genc.add(gen_enum_lookup(name, members, prefix))
 317
 318     def visit_array_type(self,
 319                          name: str,
 320                          info: Optional[QAPISourceInfo],
 321                          ifcond: Sequence[str],
 322                          element_type: QAPISchemaType) -> None:
 323         with ifcontext(ifcond, self._genh, self._genc):
 324             self._genh.preamble_add(gen_fwd_object_or_array(name))
 325             self._genh.add(gen_array(name, element_type))
 326             self._gen_type_cleanup(name)
 327
 328     def visit_object_type(self,
 329                           name: str,
 330                           info: Optional[QAPISourceInfo],
 331                           ifcond: Sequence[str],
 332                           features: List[QAPISchemaFeature],
 333                           base: Optional[QAPISchemaObjectType],
 334                           members: List[QAPISchemaObjectTypeMember],
 335                           variants: Optional[QAPISchemaVariants]) -> None:
 336         # Nothing to do for the special empty builtin
 337         if name == 'q_empty':
 338             return
 339         with ifcontext(ifcond, self._genh):
 340             self._genh.preamble_add(gen_fwd_object_or_array(name))
 341         self._genh.add(gen_object(name, ifcond, base, members, variants))
 342         with ifcontext(ifcond, self._genh, self._genc):
 343             if base and not base.is_implicit():
 344                 self._genh.add(gen_upcast(name, base))
 345             # TODO Worth changing the visitor signature, so we could
 346             # directly use rather than repeat type.is_implicit()?
 347             if not name.startswith('q_'):
 348                 # implicit types won't be directly allocated/freed
 349                 self._gen_type_cleanup(name)
 350
 351     def visit_alternate_type(self,
 352                              name: str,
 353                              info: Optional[QAPISourceInfo],
 354                              ifcond: Sequence[str],
 355                              features: List[QAPISchemaFeature],
 356                              variants: QAPISchemaVariants) -> None:
 357         with ifcontext(ifcond, self._genh):
 358             self._genh.preamble_add(gen_fwd_object_or_array(name))
 359         self._genh.add(gen_object(name, ifcond, None,
 360                                   [variants.tag_member], variants))
 361         with ifcontext(ifcond, self._genh, self._genc):
 362             self._gen_type_cleanup(name)
 363
 364
 365 def gen_types(schema: QAPISchema,
 366               output_dir: str,
 367               prefix: str,
 368               opt_builtins: bool) -> None:
 369     vis = QAPISchemaGenTypeVisitor(prefix)
 370     schema.visit(vis)
 371     vis.write(output_dir, opt_builtins)