xref: /qemu/scripts/qapi/visit.py (revision 42c0dd122299cf2aa6ef8668afe95f4c332833df) 
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 .common import (
17    c_enum_const,
18    c_name,
19    gen_endif,
20    gen_if,
21    mcgen,
22    pop_indent,
23    push_indent,
24)
25from .gen import QAPISchemaModularCVisitor, ifcontext
26from .schema import QAPISchemaObjectType
27
28
29def gen_visit_decl(name, scalar=False):
30    c_type = c_name(name) + ' *'
31    if not scalar:
32        c_type += '*'
33    return mcgen('''
34
35bool visit_type_%(c_name)s(Visitor *v, const char *name,
36                 %(c_type)sobj, Error **errp);
37''',
38                 c_name=c_name(name), c_type=c_type)
39
40
41def gen_visit_members_decl(name):
42    return mcgen('''
43
44bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
45''',
46                 c_name=c_name(name))
47
48
49def gen_visit_object_members(name, base, members, variants):
50    ret = mcgen('''
51
52bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
53{
54''',
55                c_name=c_name(name))
56
57    if base:
58        ret += mcgen('''
59    if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) {
60        return false;
61    }
62''',
63                     c_type=base.c_name())
64
65    for memb in members:
66        ret += gen_if(memb.ifcond)
67        if memb.optional:
68            ret += mcgen('''
69    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
70''',
71                         name=memb.name, c_name=c_name(memb.name))
72            push_indent()
73        ret += mcgen('''
74    if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) {
75        return false;
76    }
77''',
78                     c_type=memb.type.c_name(), name=memb.name,
79                     c_name=c_name(memb.name))
80        if memb.optional:
81            pop_indent()
82            ret += mcgen('''
83    }
84''')
85        ret += gen_endif(memb.ifcond)
86
87    if variants:
88        ret += mcgen('''
89    switch (obj->%(c_name)s) {
90''',
91                     c_name=c_name(variants.tag_member.name))
92
93        for var in variants.variants:
94            case_str = c_enum_const(variants.tag_member.type.name,
95                                    var.name,
96                                    variants.tag_member.type.prefix)
97            ret += gen_if(var.ifcond)
98            if var.type.name == 'q_empty':
99                # valid variant and nothing to do
100                ret += mcgen('''
101    case %(case)s:
102        break;
103''',
104                             case=case_str)
105            else:
106                ret += mcgen('''
107    case %(case)s:
108        return visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, errp);
109''',
110                             case=case_str,
111                             c_type=var.type.c_name(), c_name=c_name(var.name))
112
113            ret += gen_endif(var.ifcond)
114        ret += mcgen('''
115    default:
116        abort();
117    }
118''')
119
120    ret += mcgen('''
121    return true;
122}
123''')
124    return ret
125
126
127def gen_visit_list(name, element_type):
128    return mcgen('''
129
130bool visit_type_%(c_name)s(Visitor *v, const char *name,
131                 %(c_name)s **obj, Error **errp)
132{
133    bool ok = false;
134    %(c_name)s *tail;
135    size_t size = sizeof(**obj);
136
137    if (!visit_start_list(v, name, (GenericList **)obj, size, errp)) {
138        return false;
139    }
140
141    for (tail = *obj; tail;
142         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
143        if (!visit_type_%(c_elt_type)s(v, NULL, &tail->value, errp)) {
144            goto out_obj;
145        }
146    }
147
148    ok = visit_check_list(v, errp);
149out_obj:
150    visit_end_list(v, (void **)obj);
151    if (!ok && visit_is_input(v)) {
152        qapi_free_%(c_name)s(*obj);
153        *obj = NULL;
154    }
155    return ok;
156}
157''',
158                 c_name=c_name(name), c_elt_type=element_type.c_name())
159
160
161def gen_visit_enum(name):
162    return mcgen('''
163
164bool visit_type_%(c_name)s(Visitor *v, const char *name,
165                 %(c_name)s *obj, Error **errp)
166{
167    int value = *obj;
168    bool ok = visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
169    *obj = value;
170    return ok;
171}
172''',
173                 c_name=c_name(name))
174
175
176def gen_visit_alternate(name, variants):
177    ret = mcgen('''
178
179bool visit_type_%(c_name)s(Visitor *v, const char *name,
180                 %(c_name)s **obj, Error **errp)
181{
182    bool ok = false;
183
184    if (!visit_start_alternate(v, name, (GenericAlternate **)obj,
185                               sizeof(**obj), errp)) {
186        return false;
187    }
188    if (!*obj) {
189        /* incomplete */
190        assert(visit_is_dealloc(v));
191        ok = true;
192        goto out_obj;
193    }
194    switch ((*obj)->type) {
195''',
196                c_name=c_name(name))
197
198    for var in variants.variants:
199        ret += gen_if(var.ifcond)
200        ret += mcgen('''
201    case %(case)s:
202''',
203                     case=var.type.alternate_qtype())
204        if isinstance(var.type, QAPISchemaObjectType):
205            ret += mcgen('''
206        if (!visit_start_struct(v, name, NULL, 0, errp)) {
207            break;
208        }
209        if (visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, errp)) {
210            ok = visit_check_struct(v, errp);
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        ok = visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, errp);
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        assert(visit_is_input(v));
232        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
233                   "%(name)s");
234        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
235        g_free(*obj);
236        *obj = NULL;
237    }
238out_obj:
239    visit_end_alternate(v, (void **)obj);
240    if (!ok && visit_is_input(v)) {
241        qapi_free_%(c_name)s(*obj);
242        *obj = NULL;
243    }
244    return ok;
245}
246''',
247                 name=name, c_name=c_name(name))
248
249    return ret
250
251
252def gen_visit_object(name, base, members, variants):
253    return mcgen('''
254
255bool visit_type_%(c_name)s(Visitor *v, const char *name,
256                 %(c_name)s **obj, Error **errp)
257{
258    bool ok = false;
259
260    if (!visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), errp)) {
261        return false;
262    }
263    if (!*obj) {
264        /* incomplete */
265        assert(visit_is_dealloc(v));
266        ok = true;
267        goto out_obj;
268    }
269    if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
270        goto out_obj;
271    }
272    ok = visit_check_struct(v, errp);
273out_obj:
274    visit_end_struct(v, (void **)obj);
275    if (!ok && visit_is_input(v)) {
276        qapi_free_%(c_name)s(*obj);
277        *obj = NULL;
278    }
279    return ok;
280}
281''',
282                 c_name=c_name(name))
283
284
285class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
286
287    def __init__(self, prefix):
288        super().__init__(
289            prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
290            ' * Built-in QAPI visitors', __doc__)
291
292    def _begin_system_module(self, name):
293        self._genc.preamble_add(mcgen('''
294#include "qemu/osdep.h"
295#include "qapi/error.h"
296#include "qapi/qapi-builtin-visit.h"
297'''))
298        self._genh.preamble_add(mcgen('''
299#include "qapi/visitor.h"
300#include "qapi/qapi-builtin-types.h"
301
302'''))
303
304    def _begin_user_module(self, name):
305        types = self._module_basename('qapi-types', name)
306        visit = self._module_basename('qapi-visit', name)
307        self._genc.preamble_add(mcgen('''
308#include "qemu/osdep.h"
309#include "qapi/error.h"
310#include "qapi/qmp/qerror.h"
311#include "%(visit)s.h"
312''',
313                                      visit=visit))
314        self._genh.preamble_add(mcgen('''
315#include "qapi/qapi-builtin-visit.h"
316#include "%(types)s.h"
317
318''',
319                                      types=types))
320
321    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
322        with ifcontext(ifcond, self._genh, self._genc):
323            self._genh.add(gen_visit_decl(name, scalar=True))
324            self._genc.add(gen_visit_enum(name))
325
326    def visit_array_type(self, name, info, ifcond, element_type):
327        with ifcontext(ifcond, self._genh, self._genc):
328            self._genh.add(gen_visit_decl(name))
329            self._genc.add(gen_visit_list(name, element_type))
330
331    def visit_object_type(self, name, info, ifcond, features,
332                          base, members, variants):
333        # Nothing to do for the special empty builtin
334        if name == 'q_empty':
335            return
336        with ifcontext(ifcond, self._genh, self._genc):
337            self._genh.add(gen_visit_members_decl(name))
338            self._genc.add(gen_visit_object_members(name, base,
339                                                    members, variants))
340            # TODO Worth changing the visitor signature, so we could
341            # directly use rather than repeat type.is_implicit()?
342            if not name.startswith('q_'):
343                # only explicit types need an allocating visit
344                self._genh.add(gen_visit_decl(name))
345                self._genc.add(gen_visit_object(name, base, members, variants))
346
347    def visit_alternate_type(self, name, info, ifcond, features, variants):
348        with ifcontext(ifcond, self._genh, self._genc):
349            self._genh.add(gen_visit_decl(name))
350            self._genc.add(gen_visit_alternate(name, variants))
351
352
353def gen_visit(schema, output_dir, prefix, opt_builtins):
354    vis = QAPISchemaGenVisitVisitor(prefix)
355    schema.visit(vis)
356    vis.write(output_dir, opt_builtins)
357