xref: /openbmc/qemu/scripts/qapi/types.py (revision cd073c8fb0e86f135dbc573c2651863867183a75) 
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 typing import List, Optional
17
18from .common import (
19    c_enum_const,
20    c_name,
21    gen_endif,
22    gen_if,
23    mcgen,
24)
25from .gen import QAPISchemaModularCVisitor, ifcontext
26from .schema import (
27    QAPISchema,
28    QAPISchemaEnumMember,
29    QAPISchemaFeature,
30    QAPISchemaObjectType,
31    QAPISchemaObjectTypeMember,
32    QAPISchemaType,
33    QAPISchemaVariants,
34)
35from .source import QAPISourceInfo
36
37
38# variants must be emitted before their container; track what has already
39# been output
40objects_seen = set()
41
42
43def gen_enum_lookup(name: str,
44                    members: List[QAPISchemaEnumMember],
45                    prefix: Optional[str] = None) -> str:
46    ret = mcgen('''
47
48const QEnumLookup %(c_name)s_lookup = {
49    .array = (const char *const[]) {
50''',
51                c_name=c_name(name))
52    for m in members:
53        ret += gen_if(m.ifcond)
54        index = c_enum_const(name, m.name, prefix)
55        ret += mcgen('''
56        [%(index)s] = "%(name)s",
57''',
58                     index=index, name=m.name)
59        ret += gen_endif(m.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
70def 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
78typedef enum %(c_name)s {
79''',
80                c_name=c_name(name))
81
82    for m in enum_members:
83        ret += gen_if(m.ifcond)
84        ret += mcgen('''
85    %(c_enum)s,
86''',
87                     c_enum=c_enum_const(name, m.name, prefix))
88        ret += gen_endif(m.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
100extern const QEnumLookup %(c_name)s_lookup;
101''',
102                 c_name=c_name(name))
103    return ret
104
105
106def gen_fwd_object_or_array(name: str) -> str:
107    return mcgen('''
108
109typedef struct %(c_name)s %(c_name)s;
110''',
111                 c_name=c_name(name))
112
113
114def gen_array(name: str, element_type: QAPISchemaType) -> str:
115    return mcgen('''
116
117struct %(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
125def 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
142def gen_object(name: str, ifcond: List[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    if variants:
152        for v in variants.variants:
153            if isinstance(v.type, QAPISchemaObjectType):
154                ret += gen_object(v.type.name, v.type.ifcond, v.type.base,
155                                  v.type.local_members, v.type.variants)
156
157    ret += mcgen('''
158
159''')
160    ret += gen_if(ifcond)
161    ret += mcgen('''
162struct %(c_name)s {
163''',
164                 c_name=c_name(name))
165
166    if base:
167        if not base.is_implicit():
168            ret += mcgen('''
169    /* Members inherited from %(c_name)s: */
170''',
171                         c_name=base.c_name())
172        ret += gen_struct_members(base.members)
173        if not base.is_implicit():
174            ret += mcgen('''
175    /* Own members: */
176''')
177    ret += gen_struct_members(members)
178
179    if variants:
180        ret += gen_variants(variants)
181
182    # Make sure that all structs have at least one member; this avoids
183    # potential issues with attempting to malloc space for zero-length
184    # structs in C, and also incompatibility with C++ (where an empty
185    # struct is size 1).
186    if (not base or base.is_empty()) and not members and not variants:
187        ret += mcgen('''
188    char qapi_dummy_for_empty_struct;
189''')
190
191    ret += mcgen('''
192};
193''')
194    ret += gen_endif(ifcond)
195
196    return ret
197
198
199def gen_upcast(name: str, base: QAPISchemaObjectType) -> str:
200    # C makes const-correctness ugly.  We have to cast away const to let
201    # this function work for both const and non-const obj.
202    return mcgen('''
203
204static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
205{
206    return (%(base)s *)obj;
207}
208''',
209                 c_name=c_name(name), base=base.c_name())
210
211
212def gen_variants(variants: QAPISchemaVariants) -> str:
213    ret = mcgen('''
214    union { /* union tag is @%(c_name)s */
215''',
216                c_name=c_name(variants.tag_member.name))
217
218    for var in variants.variants:
219        if var.type.name == 'q_empty':
220            continue
221        ret += gen_if(var.ifcond)
222        ret += mcgen('''
223        %(c_type)s %(c_name)s;
224''',
225                     c_type=var.type.c_unboxed_type(),
226                     c_name=c_name(var.name))
227        ret += gen_endif(var.ifcond)
228
229    ret += mcgen('''
230    } u;
231''')
232
233    return ret
234
235
236def gen_type_cleanup_decl(name: str) -> str:
237    ret = mcgen('''
238
239void qapi_free_%(c_name)s(%(c_name)s *obj);
240G_DEFINE_AUTOPTR_CLEANUP_FUNC(%(c_name)s, qapi_free_%(c_name)s)
241''',
242                c_name=c_name(name))
243    return ret
244
245
246def gen_type_cleanup(name: str) -> str:
247    ret = mcgen('''
248
249void qapi_free_%(c_name)s(%(c_name)s *obj)
250{
251    Visitor *v;
252
253    if (!obj) {
254        return;
255    }
256
257    v = qapi_dealloc_visitor_new();
258    visit_type_%(c_name)s(v, NULL, &obj, NULL);
259    visit_free(v);
260}
261''',
262                c_name=c_name(name))
263    return ret
264
265
266class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
267
268    def __init__(self, prefix: str):
269        super().__init__(
270            prefix, 'qapi-types', ' * Schema-defined QAPI types',
271            ' * Built-in QAPI types', __doc__)
272
273    def _begin_system_module(self, name: None) -> None:
274        self._genc.preamble_add(mcgen('''
275#include "qemu/osdep.h"
276#include "qapi/dealloc-visitor.h"
277#include "qapi/qapi-builtin-types.h"
278#include "qapi/qapi-builtin-visit.h"
279'''))
280        self._genh.preamble_add(mcgen('''
281#include "qapi/util.h"
282'''))
283
284    def _begin_user_module(self, name: str) -> None:
285        types = self._module_basename('qapi-types', name)
286        visit = self._module_basename('qapi-visit', name)
287        self._genc.preamble_add(mcgen('''
288#include "qemu/osdep.h"
289#include "qapi/dealloc-visitor.h"
290#include "%(types)s.h"
291#include "%(visit)s.h"
292''',
293                                      types=types, visit=visit))
294        self._genh.preamble_add(mcgen('''
295#include "qapi/qapi-builtin-types.h"
296'''))
297
298    def visit_begin(self, schema: QAPISchema) -> None:
299        # gen_object() is recursive, ensure it doesn't visit the empty type
300        objects_seen.add(schema.the_empty_object_type.name)
301
302    def _gen_type_cleanup(self, name: str) -> None:
303        self._genh.add(gen_type_cleanup_decl(name))
304        self._genc.add(gen_type_cleanup(name))
305
306    def visit_enum_type(self,
307                        name: str,
308                        info: Optional[QAPISourceInfo],
309                        ifcond: List[str],
310                        features: List[QAPISchemaFeature],
311                        members: List[QAPISchemaEnumMember],
312                        prefix: Optional[str]) -> None:
313        with ifcontext(ifcond, self._genh, self._genc):
314            self._genh.preamble_add(gen_enum(name, members, prefix))
315            self._genc.add(gen_enum_lookup(name, members, prefix))
316
317    def visit_array_type(self,
318                         name: str,
319                         info: Optional[QAPISourceInfo],
320                         ifcond: List[str],
321                         element_type: QAPISchemaType) -> None:
322        with ifcontext(ifcond, self._genh, self._genc):
323            self._genh.preamble_add(gen_fwd_object_or_array(name))
324            self._genh.add(gen_array(name, element_type))
325            self._gen_type_cleanup(name)
326
327    def visit_object_type(self,
328                          name: str,
329                          info: Optional[QAPISourceInfo],
330                          ifcond: List[str],
331                          features: List[QAPISchemaFeature],
332                          base: Optional[QAPISchemaObjectType],
333                          members: List[QAPISchemaObjectTypeMember],
334                          variants: Optional[QAPISchemaVariants]) -> None:
335        # Nothing to do for the special empty builtin
336        if name == 'q_empty':
337            return
338        with ifcontext(ifcond, self._genh):
339            self._genh.preamble_add(gen_fwd_object_or_array(name))
340        self._genh.add(gen_object(name, ifcond, base, members, variants))
341        with ifcontext(ifcond, self._genh, self._genc):
342            if base and not base.is_implicit():
343                self._genh.add(gen_upcast(name, base))
344            # TODO Worth changing the visitor signature, so we could
345            # directly use rather than repeat type.is_implicit()?
346            if not name.startswith('q_'):
347                # implicit types won't be directly allocated/freed
348                self._gen_type_cleanup(name)
349
350    def visit_alternate_type(self,
351                             name: str,
352                             info: QAPISourceInfo,
353                             ifcond: List[str],
354                             features: List[QAPISchemaFeature],
355                             variants: QAPISchemaVariants) -> None:
356        with ifcontext(ifcond, self._genh):
357            self._genh.preamble_add(gen_fwd_object_or_array(name))
358        self._genh.add(gen_object(name, ifcond, None,
359                                  [variants.tag_member], variants))
360        with ifcontext(ifcond, self._genh, self._genc):
361            self._gen_type_cleanup(name)
362
363
364def gen_types(schema: QAPISchema,
365              output_dir: str,
366              prefix: str,
367              opt_builtins: bool) -> None:
368    vis = QAPISchemaGenTypeVisitor(prefix)
369    schema.visit(vis)
370    vis.write(output_dir, opt_builtins)
371