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