xref: /qemu/scripts/qapi/visit.py (revision 727385c4) 
1"""
2QAPI visitor generator
3
4Copyright IBM, Corp. 2011
5Copyright (C) 2014-2018 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.
13See 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    indent,
22    mcgen,
23)
24from .gen import QAPISchemaModularCVisitor, gen_special_features, ifcontext
25from .schema import (
26    QAPISchema,
27    QAPISchemaEnumMember,
28    QAPISchemaEnumType,
29    QAPISchemaFeature,
30    QAPISchemaIfCond,
31    QAPISchemaObjectType,
32    QAPISchemaObjectTypeMember,
33    QAPISchemaType,
34    QAPISchemaVariants,
35)
36from .source import QAPISourceInfo
37
38
39def gen_visit_decl(name: str, scalar: bool = False) -> str:
40    c_type = c_name(name) + ' *'
41    if not scalar:
42        c_type += '*'
43    return mcgen('''
44
45bool visit_type_%(c_name)s(Visitor *v, const char *name,
46                 %(c_type)sobj, Error **errp);
47''',
48                 c_name=c_name(name), c_type=c_type)
49
50
51def gen_visit_members_decl(name: str) -> str:
52    return mcgen('''
53
54bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
55''',
56                 c_name=c_name(name))
57
58
59def gen_visit_object_members(name: str,
60                             base: Optional[QAPISchemaObjectType],
61                             members: List[QAPISchemaObjectTypeMember],
62                             variants: Optional[QAPISchemaVariants]) -> str:
63    ret = mcgen('''
64
65bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
66{
67''',
68                c_name=c_name(name))
69
70    if base:
71        ret += mcgen('''
72    if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) {
73        return false;
74    }
75''',
76                     c_type=base.c_name())
77
78    for memb in members:
79        ret += memb.ifcond.gen_if()
80        if memb.optional:
81            ret += mcgen('''
82    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
83''',
84                         name=memb.name, c_name=c_name(memb.name))
85            indent.increase()
86        special_features = gen_special_features(memb.features)
87        if special_features != '0':
88            ret += mcgen('''
89    if (visit_policy_reject(v, "%(name)s", %(special_features)s, errp)) {
90        return false;
91    }
92    if (!visit_policy_skip(v, "%(name)s", %(special_features)s)) {
93''',
94                         name=memb.name, special_features=special_features)
95            indent.increase()
96        ret += mcgen('''
97    if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) {
98        return false;
99    }
100''',
101                     c_type=memb.type.c_name(), name=memb.name,
102                     c_name=c_name(memb.name))
103        if special_features != '0':
104            indent.decrease()
105            ret += mcgen('''
106    }
107''')
108        if memb.optional:
109            indent.decrease()
110            ret += mcgen('''
111    }
112''')
113        ret += memb.ifcond.gen_endif()
114
115    if variants:
116        tag_member = variants.tag_member
117        assert isinstance(tag_member.type, QAPISchemaEnumType)
118
119        ret += mcgen('''
120    switch (obj->%(c_name)s) {
121''',
122                     c_name=c_name(tag_member.name))
123
124        for var in variants.variants:
125            case_str = c_enum_const(tag_member.type.name, var.name,
126                                    tag_member.type.prefix)
127            ret += var.ifcond.gen_if()
128            if var.type.name == 'q_empty':
129                # valid variant and nothing to do
130                ret += mcgen('''
131    case %(case)s:
132        break;
133''',
134                             case=case_str)
135            else:
136                ret += mcgen('''
137    case %(case)s:
138        return visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, errp);
139''',
140                             case=case_str,
141                             c_type=var.type.c_name(), c_name=c_name(var.name))
142
143            ret += var.ifcond.gen_endif()
144        ret += mcgen('''
145    default:
146        abort();
147    }
148''')
149
150    ret += mcgen('''
151    return true;
152}
153''')
154    return ret
155
156
157def gen_visit_list(name: str, element_type: QAPISchemaType) -> str:
158    return mcgen('''
159
160bool visit_type_%(c_name)s(Visitor *v, const char *name,
161                 %(c_name)s **obj, Error **errp)
162{
163    bool ok = false;
164    %(c_name)s *tail;
165    size_t size = sizeof(**obj);
166
167    if (!visit_start_list(v, name, (GenericList **)obj, size, errp)) {
168        return false;
169    }
170
171    for (tail = *obj; tail;
172         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
173        if (!visit_type_%(c_elt_type)s(v, NULL, &tail->value, errp)) {
174            goto out_obj;
175        }
176    }
177
178    ok = visit_check_list(v, errp);
179out_obj:
180    visit_end_list(v, (void **)obj);
181    if (!ok && visit_is_input(v)) {
182        qapi_free_%(c_name)s(*obj);
183        *obj = NULL;
184    }
185    return ok;
186}
187''',
188                 c_name=c_name(name), c_elt_type=element_type.c_name())
189
190
191def gen_visit_enum(name: str) -> str:
192    return mcgen('''
193
194bool visit_type_%(c_name)s(Visitor *v, const char *name,
195                 %(c_name)s *obj, Error **errp)
196{
197    int value = *obj;
198    bool ok = visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
199    *obj = value;
200    return ok;
201}
202''',
203                 c_name=c_name(name))
204
205
206def gen_visit_alternate(name: str, variants: QAPISchemaVariants) -> str:
207    ret = mcgen('''
208
209bool visit_type_%(c_name)s(Visitor *v, const char *name,
210                 %(c_name)s **obj, Error **errp)
211{
212    bool ok = false;
213
214    if (!visit_start_alternate(v, name, (GenericAlternate **)obj,
215                               sizeof(**obj), errp)) {
216        return false;
217    }
218    if (!*obj) {
219        /* incomplete */
220        assert(visit_is_dealloc(v));
221        ok = true;
222        goto out_obj;
223    }
224    switch ((*obj)->type) {
225''',
226                c_name=c_name(name))
227
228    for var in variants.variants:
229        ret += var.ifcond.gen_if()
230        ret += mcgen('''
231    case %(case)s:
232''',
233                     case=var.type.alternate_qtype())
234        if isinstance(var.type, QAPISchemaObjectType):
235            ret += mcgen('''
236        if (!visit_start_struct(v, name, NULL, 0, errp)) {
237            break;
238        }
239        if (visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, errp)) {
240            ok = visit_check_struct(v, errp);
241        }
242        visit_end_struct(v, NULL);
243''',
244                         c_type=var.type.c_name(),
245                         c_name=c_name(var.name))
246        else:
247            ret += mcgen('''
248        ok = visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, errp);
249''',
250                         c_type=var.type.c_name(),
251                         c_name=c_name(var.name))
252        ret += mcgen('''
253        break;
254''')
255        ret += var.ifcond.gen_endif()
256
257    ret += mcgen('''
258    case QTYPE_NONE:
259        abort();
260    default:
261        assert(visit_is_input(v));
262        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
263                   "%(name)s");
264        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
265        g_free(*obj);
266        *obj = NULL;
267    }
268out_obj:
269    visit_end_alternate(v, (void **)obj);
270    if (!ok && visit_is_input(v)) {
271        qapi_free_%(c_name)s(*obj);
272        *obj = NULL;
273    }
274    return ok;
275}
276''',
277                 name=name, c_name=c_name(name))
278
279    return ret
280
281
282def gen_visit_object(name: str) -> str:
283    return mcgen('''
284
285bool visit_type_%(c_name)s(Visitor *v, const char *name,
286                 %(c_name)s **obj, Error **errp)
287{
288    bool ok = false;
289
290    if (!visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), errp)) {
291        return false;
292    }
293    if (!*obj) {
294        /* incomplete */
295        assert(visit_is_dealloc(v));
296        ok = true;
297        goto out_obj;
298    }
299    if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
300        goto out_obj;
301    }
302    ok = visit_check_struct(v, errp);
303out_obj:
304    visit_end_struct(v, (void **)obj);
305    if (!ok && visit_is_input(v)) {
306        qapi_free_%(c_name)s(*obj);
307        *obj = NULL;
308    }
309    return ok;
310}
311''',
312                 c_name=c_name(name))
313
314
315class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
316
317    def __init__(self, prefix: str):
318        super().__init__(
319            prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
320            ' * Built-in QAPI visitors', __doc__)
321
322    def _begin_builtin_module(self) -> None:
323        self._genc.preamble_add(mcgen('''
324#include "qemu/osdep.h"
325#include "qapi/error.h"
326#include "qapi/qapi-builtin-visit.h"
327'''))
328        self._genh.preamble_add(mcgen('''
329#include "qapi/visitor.h"
330#include "qapi/qapi-builtin-types.h"
331
332'''))
333
334    def _begin_user_module(self, name: str) -> None:
335        types = self._module_basename('qapi-types', name)
336        visit = self._module_basename('qapi-visit', name)
337        self._genc.preamble_add(mcgen('''
338#include "qemu/osdep.h"
339#include "qapi/error.h"
340#include "qapi/qmp/qerror.h"
341#include "%(visit)s.h"
342''',
343                                      visit=visit))
344        self._genh.preamble_add(mcgen('''
345#include "qapi/qapi-builtin-visit.h"
346#include "%(types)s.h"
347
348''',
349                                      types=types))
350
351    def visit_enum_type(self,
352                        name: str,
353                        info: Optional[QAPISourceInfo],
354                        ifcond: QAPISchemaIfCond,
355                        features: List[QAPISchemaFeature],
356                        members: List[QAPISchemaEnumMember],
357                        prefix: Optional[str]) -> None:
358        with ifcontext(ifcond, self._genh, self._genc):
359            self._genh.add(gen_visit_decl(name, scalar=True))
360            self._genc.add(gen_visit_enum(name))
361
362    def visit_array_type(self,
363                         name: str,
364                         info: Optional[QAPISourceInfo],
365                         ifcond: QAPISchemaIfCond,
366                         element_type: QAPISchemaType) -> None:
367        with ifcontext(ifcond, self._genh, self._genc):
368            self._genh.add(gen_visit_decl(name))
369            self._genc.add(gen_visit_list(name, element_type))
370
371    def visit_object_type(self,
372                          name: str,
373                          info: Optional[QAPISourceInfo],
374                          ifcond: QAPISchemaIfCond,
375                          features: List[QAPISchemaFeature],
376                          base: Optional[QAPISchemaObjectType],
377                          members: List[QAPISchemaObjectTypeMember],
378                          variants: Optional[QAPISchemaVariants]) -> None:
379        # Nothing to do for the special empty builtin
380        if name == 'q_empty':
381            return
382        with ifcontext(ifcond, self._genh, self._genc):
383            self._genh.add(gen_visit_members_decl(name))
384            self._genc.add(gen_visit_object_members(name, base,
385                                                    members, variants))
386            # TODO Worth changing the visitor signature, so we could
387            # directly use rather than repeat type.is_implicit()?
388            if not name.startswith('q_'):
389                # only explicit types need an allocating visit
390                self._genh.add(gen_visit_decl(name))
391                self._genc.add(gen_visit_object(name))
392
393    def visit_alternate_type(self,
394                             name: str,
395                             info: Optional[QAPISourceInfo],
396                             ifcond: QAPISchemaIfCond,
397                             features: List[QAPISchemaFeature],
398                             variants: QAPISchemaVariants) -> None:
399        with ifcontext(ifcond, self._genh, self._genc):
400            self._genh.add(gen_visit_decl(name))
401            self._genc.add(gen_visit_alternate(name, variants))
402
403
404def gen_visit(schema: QAPISchema,
405              output_dir: str,
406              prefix: str,
407              opt_builtins: bool) -> None:
408    vis = QAPISchemaGenVisitVisitor(prefix)
409    schema.visit(vis)
410    vis.write(output_dir, opt_builtins)
411