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