xref: /qemu/scripts/qapi/visit.py (revision a81df1b6) 
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 qapi.common import *
17from qapi.gen import QAPISchemaModularCVisitor, ifcontext
18from qapi.schema import QAPISchemaObjectType
19
20
21def gen_visit_decl(name, scalar=False):
22    c_type = c_name(name) + ' *'
23    if not scalar:
24        c_type += '*'
25    return mcgen('''
26bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
27''',
28                 c_name=c_name(name), c_type=c_type)
29
30
31def gen_visit_members_decl(name):
32    return mcgen('''
33
34bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
35''',
36                 c_name=c_name(name))
37
38
39def gen_visit_object_members(name, base, members, variants):
40    ret = mcgen('''
41
42bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
43{
44''',
45                c_name=c_name(name))
46
47    if base:
48        ret += mcgen('''
49    if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) {
50        return false;
51    }
52''',
53                     c_type=base.c_name())
54
55    for memb in members:
56        ret += gen_if(memb.ifcond)
57        if memb.optional:
58            ret += mcgen('''
59    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
60''',
61                         name=memb.name, c_name=c_name(memb.name))
62            push_indent()
63        ret += mcgen('''
64    if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) {
65        return false;
66    }
67''',
68                     c_type=memb.type.c_name(), name=memb.name,
69                     c_name=c_name(memb.name))
70        if memb.optional:
71            pop_indent()
72            ret += mcgen('''
73    }
74''')
75        ret += gen_endif(memb.ifcond)
76
77    if variants:
78        ret += mcgen('''
79    switch (obj->%(c_name)s) {
80''',
81                     c_name=c_name(variants.tag_member.name))
82
83        for var in variants.variants:
84            case_str = c_enum_const(variants.tag_member.type.name,
85                                    var.name,
86                                    variants.tag_member.type.prefix)
87            ret += gen_if(var.ifcond)
88            if var.type.name == 'q_empty':
89                # valid variant and nothing to do
90                ret += mcgen('''
91    case %(case)s:
92        break;
93''',
94                             case=case_str)
95            else:
96                ret += mcgen('''
97    case %(case)s:
98        return visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, errp);
99''',
100                             case=case_str,
101                             c_type=var.type.c_name(), c_name=c_name(var.name))
102
103            ret += gen_endif(var.ifcond)
104        ret += mcgen('''
105    default:
106        abort();
107    }
108''')
109
110    ret += mcgen('''
111    return true;
112}
113''')
114    return ret
115
116
117def gen_visit_list(name, element_type):
118    return mcgen('''
119
120bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
121{
122    bool ok = false;
123    %(c_name)s *tail;
124    size_t size = sizeof(**obj);
125
126    if (!visit_start_list(v, name, (GenericList **)obj, size, errp)) {
127        return false;
128    }
129
130    for (tail = *obj; tail;
131         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
132        if (!visit_type_%(c_elt_type)s(v, NULL, &tail->value, errp)) {
133            goto out_obj;
134        }
135    }
136
137    ok = visit_check_list(v, errp);
138out_obj:
139    visit_end_list(v, (void **)obj);
140    if (!ok && visit_is_input(v)) {
141        qapi_free_%(c_name)s(*obj);
142        *obj = NULL;
143    }
144    return ok;
145}
146''',
147                 c_name=c_name(name), c_elt_type=element_type.c_name())
148
149
150def gen_visit_enum(name):
151    return mcgen('''
152
153bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
154{
155    int value = *obj;
156    bool ok = visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
157    *obj = value;
158    return ok;
159}
160''',
161                 c_name=c_name(name))
162
163
164def gen_visit_alternate(name, variants):
165    ret = mcgen('''
166
167bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
168{
169    bool ok = false;
170
171    if (!visit_start_alternate(v, name, (GenericAlternate **)obj,
172                               sizeof(**obj), errp)) {
173        return false;
174    }
175    if (!*obj) {
176        /* incomplete */
177        assert(visit_is_dealloc(v));
178        ok = true;
179        goto out_obj;
180    }
181    switch ((*obj)->type) {
182''',
183                c_name=c_name(name))
184
185    for var in variants.variants:
186        ret += gen_if(var.ifcond)
187        ret += mcgen('''
188    case %(case)s:
189''',
190                     case=var.type.alternate_qtype())
191        if isinstance(var.type, QAPISchemaObjectType):
192            ret += mcgen('''
193        if (!visit_start_struct(v, name, NULL, 0, errp)) {
194            break;
195        }
196        if (visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, errp)) {
197            ok = visit_check_struct(v, errp);
198        }
199        visit_end_struct(v, NULL);
200''',
201                         c_type=var.type.c_name(),
202                         c_name=c_name(var.name))
203        else:
204            ret += mcgen('''
205        ok = visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, errp);
206''',
207                         c_type=var.type.c_name(),
208                         c_name=c_name(var.name))
209        ret += mcgen('''
210        break;
211''')
212        ret += gen_endif(var.ifcond)
213
214    ret += mcgen('''
215    case QTYPE_NONE:
216        abort();
217    default:
218        assert(visit_is_input(v));
219        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
220                   "%(name)s");
221        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
222        g_free(*obj);
223        *obj = NULL;
224    }
225out_obj:
226    visit_end_alternate(v, (void **)obj);
227    if (!ok && visit_is_input(v)) {
228        qapi_free_%(c_name)s(*obj);
229        *obj = NULL;
230    }
231    return ok;
232}
233''',
234                 name=name, c_name=c_name(name))
235
236    return ret
237
238
239def gen_visit_object(name, base, members, variants):
240    return mcgen('''
241
242bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
243{
244    bool ok = false;
245
246    if (!visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), errp)) {
247        return false;
248    }
249    if (!*obj) {
250        /* incomplete */
251        assert(visit_is_dealloc(v));
252        ok = true;
253        goto out_obj;
254    }
255    if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
256        goto out_obj;
257    }
258    ok = visit_check_struct(v, errp);
259out_obj:
260    visit_end_struct(v, (void **)obj);
261    if (!ok && visit_is_input(v)) {
262        qapi_free_%(c_name)s(*obj);
263        *obj = NULL;
264    }
265    return ok;
266}
267''',
268                 c_name=c_name(name))
269
270
271class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
272
273    def __init__(self, prefix):
274        super().__init__(
275            prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
276            ' * Built-in QAPI visitors', __doc__)
277
278    def _begin_system_module(self, name):
279        self._genc.preamble_add(mcgen('''
280#include "qemu/osdep.h"
281#include "qapi/error.h"
282#include "qapi/qapi-builtin-visit.h"
283'''))
284        self._genh.preamble_add(mcgen('''
285#include "qapi/visitor.h"
286#include "qapi/qapi-builtin-types.h"
287
288'''))
289
290    def _begin_user_module(self, name):
291        types = self._module_basename('qapi-types', name)
292        visit = self._module_basename('qapi-visit', name)
293        self._genc.preamble_add(mcgen('''
294#include "qemu/osdep.h"
295#include "qapi/error.h"
296#include "qapi/qmp/qerror.h"
297#include "%(visit)s.h"
298''',
299                                      visit=visit))
300        self._genh.preamble_add(mcgen('''
301#include "qapi/qapi-builtin-visit.h"
302#include "%(types)s.h"
303
304''',
305                                      types=types))
306
307    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
308        with ifcontext(ifcond, self._genh, self._genc):
309            self._genh.add(gen_visit_decl(name, scalar=True))
310            self._genc.add(gen_visit_enum(name))
311
312    def visit_array_type(self, name, info, ifcond, element_type):
313        with ifcontext(ifcond, self._genh, self._genc):
314            self._genh.add(gen_visit_decl(name))
315            self._genc.add(gen_visit_list(name, element_type))
316
317    def visit_object_type(self, name, info, ifcond, features,
318                          base, members, variants):
319        # Nothing to do for the special empty builtin
320        if name == 'q_empty':
321            return
322        with ifcontext(ifcond, self._genh, self._genc):
323            self._genh.add(gen_visit_members_decl(name))
324            self._genc.add(gen_visit_object_members(name, base,
325                                                    members, variants))
326            # TODO Worth changing the visitor signature, so we could
327            # directly use rather than repeat type.is_implicit()?
328            if not name.startswith('q_'):
329                # only explicit types need an allocating visit
330                self._genh.add(gen_visit_decl(name))
331                self._genc.add(gen_visit_object(name, base, members, variants))
332
333    def visit_alternate_type(self, name, info, ifcond, features, variants):
334        with ifcontext(ifcond, self._genh, self._genc):
335            self._genh.add(gen_visit_decl(name))
336            self._genc.add(gen_visit_alternate(name, variants))
337
338
339def gen_visit(schema, output_dir, prefix, opt_builtins):
340    vis = QAPISchemaGenVisitVisitor(prefix)
341    schema.visit(vis)
342    vis.write(output_dir, opt_builtins)
343