xref: /qemu/scripts/qapi/visit.py (revision 37677d7d) 
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 *
17
18
19def gen_visit_decl(name, scalar=False):
20    c_type = c_name(name) + ' *'
21    if not scalar:
22        c_type += '*'
23    return mcgen('''
24void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
25''',
26                 c_name=c_name(name), c_type=c_type)
27
28
29def gen_visit_members_decl(name):
30    return mcgen('''
31
32void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
33''',
34                 c_name=c_name(name))
35
36
37def gen_visit_object_members(name, base, members, variants):
38    ret = mcgen('''
39
40void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
41{
42    Error *err = NULL;
43
44''',
45                c_name=c_name(name))
46
47    if base:
48        ret += mcgen('''
49    visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, &err);
50    if (err) {
51        goto out;
52    }
53''',
54                     c_type=base.c_name())
55
56    for memb in members:
57        ret += gen_if(memb.ifcond)
58        if memb.optional:
59            ret += mcgen('''
60    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
61''',
62                         name=memb.name, c_name=c_name(memb.name))
63            push_indent()
64        ret += mcgen('''
65    visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, &err);
66    if (err) {
67        goto out;
68    }
69''',
70                     c_type=memb.type.c_name(), name=memb.name,
71                     c_name=c_name(memb.name))
72        if memb.optional:
73            pop_indent()
74            ret += mcgen('''
75    }
76''')
77        ret += gen_endif(memb.ifcond)
78
79    if variants:
80        ret += mcgen('''
81    switch (obj->%(c_name)s) {
82''',
83                     c_name=c_name(variants.tag_member.name))
84
85        for var in variants.variants:
86            case_str = c_enum_const(variants.tag_member.type.name,
87                                    var.name,
88                                    variants.tag_member.type.prefix)
89            ret += gen_if(var.ifcond)
90            if var.type.name == 'q_empty':
91                # valid variant and nothing to do
92                ret += mcgen('''
93    case %(case)s:
94        break;
95''',
96                             case=case_str)
97            else:
98                ret += mcgen('''
99    case %(case)s:
100        visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
101        break;
102''',
103                             case=case_str,
104                             c_type=var.type.c_name(), c_name=c_name(var.name))
105
106            ret += gen_endif(var.ifcond)
107        ret += mcgen('''
108    default:
109        abort();
110    }
111''')
112
113    # 'goto out' produced for base, for each member, and if variants were
114    # present
115    if base or members or variants:
116        ret += mcgen('''
117
118out:
119''')
120    ret += mcgen('''
121    error_propagate(errp, err);
122}
123''')
124    return ret
125
126
127def gen_visit_list(name, element_type):
128    return mcgen('''
129
130void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
131{
132    Error *err = NULL;
133    %(c_name)s *tail;
134    size_t size = sizeof(**obj);
135
136    visit_start_list(v, name, (GenericList **)obj, size, &err);
137    if (err) {
138        goto out;
139    }
140
141    for (tail = *obj; tail;
142         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
143        visit_type_%(c_elt_type)s(v, NULL, &tail->value, &err);
144        if (err) {
145            break;
146        }
147    }
148
149    if (!err) {
150        visit_check_list(v, &err);
151    }
152    visit_end_list(v, (void **)obj);
153    if (err && visit_is_input(v)) {
154        qapi_free_%(c_name)s(*obj);
155        *obj = NULL;
156    }
157out:
158    error_propagate(errp, err);
159}
160''',
161                 c_name=c_name(name), c_elt_type=element_type.c_name())
162
163
164def gen_visit_enum(name):
165    return mcgen('''
166
167void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
168{
169    int value = *obj;
170    visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
171    *obj = value;
172}
173''',
174                 c_name=c_name(name))
175
176
177def gen_visit_alternate(name, variants):
178    ret = mcgen('''
179
180void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
181{
182    Error *err = NULL;
183
184    visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
185                          &err);
186    if (err) {
187        goto out;
188    }
189    if (!*obj) {
190        goto out_obj;
191    }
192    switch ((*obj)->type) {
193''',
194                c_name=c_name(name))
195
196    for var in variants.variants:
197        ret += gen_if(var.ifcond)
198        ret += mcgen('''
199    case %(case)s:
200''',
201                     case=var.type.alternate_qtype())
202        if isinstance(var.type, QAPISchemaObjectType):
203            ret += mcgen('''
204        visit_start_struct(v, name, NULL, 0, &err);
205        if (err) {
206            break;
207        }
208        visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
209        if (!err) {
210            visit_check_struct(v, &err);
211        }
212        visit_end_struct(v, NULL);
213''',
214                         c_type=var.type.c_name(),
215                         c_name=c_name(var.name))
216        else:
217            ret += mcgen('''
218        visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
219''',
220                         c_type=var.type.c_name(),
221                         c_name=c_name(var.name))
222        ret += mcgen('''
223        break;
224''')
225        ret += gen_endif(var.ifcond)
226
227    ret += mcgen('''
228    case QTYPE_NONE:
229        abort();
230    default:
231        error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
232                   "%(name)s");
233    }
234out_obj:
235    visit_end_alternate(v, (void **)obj);
236    if (err && visit_is_input(v)) {
237        qapi_free_%(c_name)s(*obj);
238        *obj = NULL;
239    }
240out:
241    error_propagate(errp, err);
242}
243''',
244                 name=name, c_name=c_name(name))
245
246    return ret
247
248
249def gen_visit_object(name, base, members, variants):
250    return mcgen('''
251
252void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
253{
254    Error *err = NULL;
255
256    visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
257    if (err) {
258        goto out;
259    }
260    if (!*obj) {
261        goto out_obj;
262    }
263    visit_type_%(c_name)s_members(v, *obj, &err);
264    if (err) {
265        goto out_obj;
266    }
267    visit_check_struct(v, &err);
268out_obj:
269    visit_end_struct(v, (void **)obj);
270    if (err && visit_is_input(v)) {
271        qapi_free_%(c_name)s(*obj);
272        *obj = NULL;
273    }
274out:
275    error_propagate(errp, err);
276}
277''',
278                 c_name=c_name(name))
279
280
281class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
282
283    def __init__(self, prefix):
284        QAPISchemaModularCVisitor.__init__(
285            self, prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
286            __doc__)
287        self._add_system_module(None, ' * Built-in QAPI visitors')
288        self._genc.preamble_add(mcgen('''
289#include "qemu/osdep.h"
290#include "qapi/error.h"
291#include "qapi/qapi-builtin-visit.h"
292'''))
293        self._genh.preamble_add(mcgen('''
294#include "qapi/visitor.h"
295#include "qapi/qapi-builtin-types.h"
296
297''',
298                                      prefix=prefix))
299
300    def _begin_user_module(self, name):
301        types = self._module_basename('qapi-types', name)
302        visit = self._module_basename('qapi-visit', name)
303        self._genc.preamble_add(mcgen('''
304#include "qemu/osdep.h"
305#include "qapi/error.h"
306#include "qapi/qmp/qerror.h"
307#include "%(visit)s.h"
308''',
309                                      visit=visit))
310        self._genh.preamble_add(mcgen('''
311#include "qapi/qapi-builtin-visit.h"
312#include "%(types)s.h"
313
314''',
315                                      types=types))
316
317    def visit_enum_type(self, name, info, ifcond, members, prefix):
318        with ifcontext(ifcond, self._genh, self._genc):
319            self._genh.add(gen_visit_decl(name, scalar=True))
320            self._genc.add(gen_visit_enum(name))
321
322    def visit_array_type(self, name, info, ifcond, element_type):
323        with ifcontext(ifcond, self._genh, self._genc):
324            self._genh.add(gen_visit_decl(name))
325            self._genc.add(gen_visit_list(name, element_type))
326
327    def visit_object_type(self, name, info, ifcond, base, members, variants):
328        # Nothing to do for the special empty builtin
329        if name == 'q_empty':
330            return
331        with ifcontext(ifcond, self._genh, self._genc):
332            self._genh.add(gen_visit_members_decl(name))
333            self._genc.add(gen_visit_object_members(name, base,
334                                                    members, variants))
335            # TODO Worth changing the visitor signature, so we could
336            # directly use rather than repeat type.is_implicit()?
337            if not name.startswith('q_'):
338                # only explicit types need an allocating visit
339                self._genh.add(gen_visit_decl(name))
340                self._genc.add(gen_visit_object(name, base, members, variants))
341
342    def visit_alternate_type(self, name, info, ifcond, variants):
343        with ifcontext(ifcond, self._genh, self._genc):
344            self._genh.add(gen_visit_decl(name))
345            self._genc.add(gen_visit_alternate(name, variants))
346
347
348def gen_visit(schema, output_dir, prefix, opt_builtins):
349    vis = QAPISchemaGenVisitVisitor(prefix)
350    schema.visit(vis)
351    vis.write(output_dir, opt_builtins)
352