xref: /qemu/scripts/qapi/types.py (revision 5af8263d40c698c47befd4c0bed3d6c452b56d82) 
1"""
2QAPI types generator
3
4Copyright IBM, Corp. 2011
5Copyright (c) 2013-2018 Red Hat Inc.
6
7Authors:
8 Anthony Liguori <aliguori@us.ibm.com>
9 Michael Roth <mdroth@linux.vnet.ibm.com>
10 Markus Armbruster <armbru@redhat.com>
11
12This work is licensed under the terms of the GNU GPL, version 2.
13# See the COPYING file in the top-level directory.
14"""
15
16from .common import (
17    c_enum_const,
18    c_name,
19    gen_endif,
20    gen_if,
21    mcgen,
22)
23from .gen import QAPISchemaModularCVisitor, ifcontext
24from .schema import QAPISchemaEnumMember, QAPISchemaObjectType
25
26
27# variants must be emitted before their container; track what has already
28# been output
29objects_seen = set()
30
31
32def gen_enum_lookup(name, members, prefix=None):
33    ret = mcgen('''
34
35const QEnumLookup %(c_name)s_lookup = {
36    .array = (const char *const[]) {
37''',
38                c_name=c_name(name))
39    for m in members:
40        ret += gen_if(m.ifcond)
41        index = c_enum_const(name, m.name, prefix)
42        ret += mcgen('''
43        [%(index)s] = "%(name)s",
44''',
45                     index=index, name=m.name)
46        ret += gen_endif(m.ifcond)
47
48    ret += mcgen('''
49    },
50    .size = %(max_index)s
51};
52''',
53                 max_index=c_enum_const(name, '_MAX', prefix))
54    return ret
55
56
57def gen_enum(name, members, prefix=None):
58    # append automatically generated _MAX value
59    enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
60
61    ret = mcgen('''
62
63typedef enum %(c_name)s {
64''',
65                c_name=c_name(name))
66
67    for m in enum_members:
68        ret += gen_if(m.ifcond)
69        ret += mcgen('''
70    %(c_enum)s,
71''',
72                     c_enum=c_enum_const(name, m.name, prefix))
73        ret += gen_endif(m.ifcond)
74
75    ret += mcgen('''
76} %(c_name)s;
77''',
78                 c_name=c_name(name))
79
80    ret += mcgen('''
81
82#define %(c_name)s_str(val) \\
83    qapi_enum_lookup(&%(c_name)s_lookup, (val))
84
85extern const QEnumLookup %(c_name)s_lookup;
86''',
87                 c_name=c_name(name))
88    return ret
89
90
91def gen_fwd_object_or_array(name):
92    return mcgen('''
93
94typedef struct %(c_name)s %(c_name)s;
95''',
96                 c_name=c_name(name))
97
98
99def gen_array(name, element_type):
100    return mcgen('''
101
102struct %(c_name)s {
103    %(c_name)s *next;
104    %(c_type)s value;
105};
106''',
107                 c_name=c_name(name), c_type=element_type.c_type())
108
109
110def gen_struct_members(members):
111    ret = ''
112    for memb in members:
113        ret += gen_if(memb.ifcond)
114        if memb.optional:
115            ret += mcgen('''
116    bool has_%(c_name)s;
117''',
118                         c_name=c_name(memb.name))
119        ret += mcgen('''
120    %(c_type)s %(c_name)s;
121''',
122                     c_type=memb.type.c_type(), c_name=c_name(memb.name))
123        ret += gen_endif(memb.ifcond)
124    return ret
125
126
127def gen_object(name, ifcond, base, members, variants):
128    if name in objects_seen:
129        return ''
130    objects_seen.add(name)
131
132    ret = ''
133    if variants:
134        for v in variants.variants:
135            if isinstance(v.type, QAPISchemaObjectType):
136                ret += gen_object(v.type.name, v.type.ifcond, v.type.base,
137                                  v.type.local_members, v.type.variants)
138
139    ret += mcgen('''
140
141''')
142    ret += gen_if(ifcond)
143    ret += mcgen('''
144struct %(c_name)s {
145''',
146                 c_name=c_name(name))
147
148    if base:
149        if not base.is_implicit():
150            ret += mcgen('''
151    /* Members inherited from %(c_name)s: */
152''',
153                         c_name=base.c_name())
154        ret += gen_struct_members(base.members)
155        if not base.is_implicit():
156            ret += mcgen('''
157    /* Own members: */
158''')
159    ret += gen_struct_members(members)
160
161    if variants:
162        ret += gen_variants(variants)
163
164    # Make sure that all structs have at least one member; this avoids
165    # potential issues with attempting to malloc space for zero-length
166    # structs in C, and also incompatibility with C++ (where an empty
167    # struct is size 1).
168    if (not base or base.is_empty()) and not members and not variants:
169        ret += mcgen('''
170    char qapi_dummy_for_empty_struct;
171''')
172
173    ret += mcgen('''
174};
175''')
176    ret += gen_endif(ifcond)
177
178    return ret
179
180
181def gen_upcast(name, base):
182    # C makes const-correctness ugly.  We have to cast away const to let
183    # this function work for both const and non-const obj.
184    return mcgen('''
185
186static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
187{
188    return (%(base)s *)obj;
189}
190''',
191                 c_name=c_name(name), base=base.c_name())
192
193
194def gen_variants(variants):
195    ret = mcgen('''
196    union { /* union tag is @%(c_name)s */
197''',
198                c_name=c_name(variants.tag_member.name))
199
200    for var in variants.variants:
201        if var.type.name == 'q_empty':
202            continue
203        ret += gen_if(var.ifcond)
204        ret += mcgen('''
205        %(c_type)s %(c_name)s;
206''',
207                     c_type=var.type.c_unboxed_type(),
208                     c_name=c_name(var.name))
209        ret += gen_endif(var.ifcond)
210
211    ret += mcgen('''
212    } u;
213''')
214
215    return ret
216
217
218def gen_type_cleanup_decl(name):
219    ret = mcgen('''
220
221void qapi_free_%(c_name)s(%(c_name)s *obj);
222G_DEFINE_AUTOPTR_CLEANUP_FUNC(%(c_name)s, qapi_free_%(c_name)s)
223''',
224                c_name=c_name(name))
225    return ret
226
227
228def gen_type_cleanup(name):
229    ret = mcgen('''
230
231void qapi_free_%(c_name)s(%(c_name)s *obj)
232{
233    Visitor *v;
234
235    if (!obj) {
236        return;
237    }
238
239    v = qapi_dealloc_visitor_new();
240    visit_type_%(c_name)s(v, NULL, &obj, NULL);
241    visit_free(v);
242}
243''',
244                c_name=c_name(name))
245    return ret
246
247
248class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
249
250    def __init__(self, prefix):
251        super().__init__(
252            prefix, 'qapi-types', ' * Schema-defined QAPI types',
253            ' * Built-in QAPI types', __doc__)
254
255    def _begin_system_module(self, name):
256        self._genc.preamble_add(mcgen('''
257#include "qemu/osdep.h"
258#include "qapi/dealloc-visitor.h"
259#include "qapi/qapi-builtin-types.h"
260#include "qapi/qapi-builtin-visit.h"
261'''))
262        self._genh.preamble_add(mcgen('''
263#include "qapi/util.h"
264'''))
265
266    def _begin_user_module(self, name):
267        types = self._module_basename('qapi-types', name)
268        visit = self._module_basename('qapi-visit', name)
269        self._genc.preamble_add(mcgen('''
270#include "qemu/osdep.h"
271#include "qapi/dealloc-visitor.h"
272#include "%(types)s.h"
273#include "%(visit)s.h"
274''',
275                                      types=types, visit=visit))
276        self._genh.preamble_add(mcgen('''
277#include "qapi/qapi-builtin-types.h"
278'''))
279
280    def visit_begin(self, schema):
281        # gen_object() is recursive, ensure it doesn't visit the empty type
282        objects_seen.add(schema.the_empty_object_type.name)
283
284    def _gen_type_cleanup(self, name):
285        self._genh.add(gen_type_cleanup_decl(name))
286        self._genc.add(gen_type_cleanup(name))
287
288    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
289        with ifcontext(ifcond, self._genh, self._genc):
290            self._genh.preamble_add(gen_enum(name, members, prefix))
291            self._genc.add(gen_enum_lookup(name, members, prefix))
292
293    def visit_array_type(self, name, info, ifcond, element_type):
294        with ifcontext(ifcond, self._genh, self._genc):
295            self._genh.preamble_add(gen_fwd_object_or_array(name))
296            self._genh.add(gen_array(name, element_type))
297            self._gen_type_cleanup(name)
298
299    def visit_object_type(self, name, info, ifcond, features,
300                          base, members, variants):
301        # Nothing to do for the special empty builtin
302        if name == 'q_empty':
303            return
304        with ifcontext(ifcond, self._genh):
305            self._genh.preamble_add(gen_fwd_object_or_array(name))
306        self._genh.add(gen_object(name, ifcond, base, members, variants))
307        with ifcontext(ifcond, self._genh, self._genc):
308            if base and not base.is_implicit():
309                self._genh.add(gen_upcast(name, base))
310            # TODO Worth changing the visitor signature, so we could
311            # directly use rather than repeat type.is_implicit()?
312            if not name.startswith('q_'):
313                # implicit types won't be directly allocated/freed
314                self._gen_type_cleanup(name)
315
316    def visit_alternate_type(self, name, info, ifcond, features, variants):
317        with ifcontext(ifcond, self._genh):
318            self._genh.preamble_add(gen_fwd_object_or_array(name))
319        self._genh.add(gen_object(name, ifcond, None,
320                                  [variants.tag_member], variants))
321        with ifcontext(ifcond, self._genh, self._genc):
322            self._gen_type_cleanup(name)
323
324
325def gen_types(schema, output_dir, prefix, opt_builtins):
326    vis = QAPISchemaGenTypeVisitor(prefix)
327    schema.visit(vis)
328    vis.write(output_dir, opt_builtins)
329