xref: /openbmc/qemu/scripts/qapi/types.py (revision 4b9fa0b4) 
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 qapi.common import *
17from qapi.gen import QAPISchemaModularCVisitor, ifcontext
18from qapi.schema import QAPISchemaEnumMember, QAPISchemaObjectType
19
20
21# variants must be emitted before their container; track what has already
22# been output
23objects_seen = set()
24
25
26def gen_enum_lookup(name, members, prefix=None):
27    ret = mcgen('''
28
29const 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
51def gen_enum(name, members, prefix=None):
52    # append automatically generated _MAX value
53    enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
54
55    ret = mcgen('''
56
57typedef 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
79extern const QEnumLookup %(c_name)s_lookup;
80''',
81                 c_name=c_name(name))
82    return ret
83
84
85def gen_fwd_object_or_array(name):
86    return mcgen('''
87
88typedef struct %(c_name)s %(c_name)s;
89''',
90                 c_name=c_name(name))
91
92
93def gen_array(name, element_type):
94    return mcgen('''
95
96struct %(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
104def 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
121def 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('''
138struct %(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
175def 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
180static 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
188def 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
212def gen_type_cleanup_decl(name):
213    ret = mcgen('''
214
215void qapi_free_%(c_name)s(%(c_name)s *obj);
216''',
217                c_name=c_name(name))
218    return ret
219
220
221def gen_type_cleanup(name):
222    ret = mcgen('''
223
224void 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
241class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
242
243    def __init__(self, prefix):
244        QAPISchemaModularCVisitor.__init__(
245            self, prefix, 'qapi-types', ' * Schema-defined QAPI types',
246            __doc__)
247        self._add_system_module(None, ' * Built-in QAPI types')
248        self._genc.preamble_add(mcgen('''
249#include "qemu/osdep.h"
250#include "qapi/dealloc-visitor.h"
251#include "qapi/qapi-builtin-types.h"
252#include "qapi/qapi-builtin-visit.h"
253'''))
254        self._genh.preamble_add(mcgen('''
255#include "qapi/util.h"
256'''))
257
258    def _begin_user_module(self, name):
259        types = self._module_basename('qapi-types', name)
260        visit = self._module_basename('qapi-visit', name)
261        self._genc.preamble_add(mcgen('''
262#include "qemu/osdep.h"
263#include "qapi/dealloc-visitor.h"
264#include "%(types)s.h"
265#include "%(visit)s.h"
266''',
267                                      types=types, visit=visit))
268        self._genh.preamble_add(mcgen('''
269#include "qapi/qapi-builtin-types.h"
270'''))
271
272    def visit_begin(self, schema):
273        # gen_object() is recursive, ensure it doesn't visit the empty type
274        objects_seen.add(schema.the_empty_object_type.name)
275
276    def _gen_type_cleanup(self, name):
277        self._genh.add(gen_type_cleanup_decl(name))
278        self._genc.add(gen_type_cleanup(name))
279
280    def visit_enum_type(self, name, info, ifcond, members, prefix):
281        with ifcontext(ifcond, self._genh, self._genc):
282            self._genh.preamble_add(gen_enum(name, members, prefix))
283            self._genc.add(gen_enum_lookup(name, members, prefix))
284
285    def visit_array_type(self, name, info, ifcond, element_type):
286        with ifcontext(ifcond, self._genh, self._genc):
287            self._genh.preamble_add(gen_fwd_object_or_array(name))
288            self._genh.add(gen_array(name, element_type))
289            self._gen_type_cleanup(name)
290
291    def visit_object_type(self, name, info, ifcond, base, members, variants,
292                          features):
293        # Nothing to do for the special empty builtin
294        if name == 'q_empty':
295            return
296        with ifcontext(ifcond, self._genh):
297            self._genh.preamble_add(gen_fwd_object_or_array(name))
298        self._genh.add(gen_object(name, ifcond, base, members, variants))
299        with ifcontext(ifcond, self._genh, self._genc):
300            if base and not base.is_implicit():
301                self._genh.add(gen_upcast(name, base))
302            # TODO Worth changing the visitor signature, so we could
303            # directly use rather than repeat type.is_implicit()?
304            if not name.startswith('q_'):
305                # implicit types won't be directly allocated/freed
306                self._gen_type_cleanup(name)
307
308    def visit_alternate_type(self, name, info, ifcond, variants):
309        with ifcontext(ifcond, self._genh):
310            self._genh.preamble_add(gen_fwd_object_or_array(name))
311        self._genh.add(gen_object(name, ifcond, None,
312                                  [variants.tag_member], variants))
313        with ifcontext(ifcond, self._genh, self._genc):
314            self._gen_type_cleanup(name)
315
316
317def gen_types(schema, output_dir, prefix, opt_builtins):
318    vis = QAPISchemaGenTypeVisitor(prefix)
319    schema.visit(vis)
320    vis.write(output_dir, opt_builtins)
321