xref: /qemu/scripts/qapi/visit.py (revision 68ab47e4b4ecc1c4649362b8cc1e49794d1a6537) 
1#
2# QAPI visitor generator
3#
4# Copyright IBM, Corp. 2011
5# Copyright (C) 2014-2016 Red Hat, Inc.
6#
7# Authors:
8#  Anthony Liguori <aliguori@us.ibm.com>
9#  Michael Roth    <mdroth@linux.vnet.ibm.com>
10#  Markus Armbruster <armbru@redhat.com>
11#
12# This work is licensed under the terms of the GNU GPL, version 2.
13# See the COPYING file in the top-level directory.
14
15from qapi import *
16import re
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''',
51                     c_type=base.c_name())
52        ret += gen_err_check()
53
54    for memb in members:
55        if memb.optional:
56            ret += mcgen('''
57    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
58''',
59                         name=memb.name, c_name=c_name(memb.name))
60            push_indent()
61        ret += mcgen('''
62    visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, &err);
63''',
64                     c_type=memb.type.c_name(), name=memb.name,
65                     c_name=c_name(memb.name))
66        ret += gen_err_check()
67        if memb.optional:
68            pop_indent()
69            ret += mcgen('''
70    }
71''')
72
73    if variants:
74        ret += mcgen('''
75    switch (obj->%(c_name)s) {
76''',
77                     c_name=c_name(variants.tag_member.name))
78
79        for var in variants.variants:
80            ret += mcgen('''
81    case %(case)s:
82        visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
83        break;
84''',
85                         case=c_enum_const(variants.tag_member.type.name,
86                                           var.name,
87                                           variants.tag_member.type.prefix),
88                         c_type=var.type.c_name(), c_name=c_name(var.name))
89
90        ret += mcgen('''
91    default:
92        abort();
93    }
94''')
95
96    # 'goto out' produced for base, for each member, and if variants were
97    # present
98    if base or members or variants:
99        ret += mcgen('''
100
101out:
102''')
103    ret += mcgen('''
104    error_propagate(errp, err);
105}
106''')
107    return ret
108
109
110def gen_visit_list(name, element_type):
111    return mcgen('''
112
113void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
114{
115    Error *err = NULL;
116    %(c_name)s *tail;
117    size_t size = sizeof(**obj);
118
119    visit_start_list(v, name, (GenericList **)obj, size, &err);
120    if (err) {
121        goto out;
122    }
123
124    for (tail = *obj; tail;
125         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
126        visit_type_%(c_elt_type)s(v, NULL, &tail->value, &err);
127        if (err) {
128            break;
129        }
130    }
131
132    visit_end_list(v);
133    if (err && visit_is_input(v)) {
134        qapi_free_%(c_name)s(*obj);
135        *obj = NULL;
136    }
137out:
138    error_propagate(errp, err);
139}
140''',
141                 c_name=c_name(name), c_elt_type=element_type.c_name())
142
143
144def gen_visit_enum(name):
145    return mcgen('''
146
147void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
148{
149    int value = *obj;
150    visit_type_enum(v, name, &value, %(c_name)s_lookup, errp);
151    *obj = value;
152}
153''',
154                 c_name=c_name(name))
155
156
157def gen_visit_alternate(name, variants):
158    promote_int = 'true'
159    ret = ''
160    for var in variants.variants:
161        if var.type.alternate_qtype() == 'QTYPE_QINT':
162            promote_int = 'false'
163
164    ret += mcgen('''
165
166void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
167{
168    Error *err = NULL;
169
170    visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
171                          %(promote_int)s, &err);
172    if (err) {
173        goto out;
174    }
175    switch ((*obj)->type) {
176''',
177                 c_name=c_name(name), promote_int=promote_int)
178
179    for var in variants.variants:
180        ret += mcgen('''
181    case %(case)s:
182''',
183                     case=var.type.alternate_qtype())
184        if isinstance(var.type, QAPISchemaObjectType):
185            ret += mcgen('''
186        visit_start_struct(v, name, NULL, 0, &err);
187        if (err) {
188            break;
189        }
190        visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
191        if (!err) {
192            visit_check_struct(v, &err);
193        }
194        visit_end_struct(v);
195''',
196                         c_type=var.type.c_name(),
197                         c_name=c_name(var.name))
198        else:
199            ret += mcgen('''
200        visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
201''',
202                         c_type=var.type.c_name(),
203                         c_name=c_name(var.name))
204        ret += mcgen('''
205        break;
206''')
207
208    ret += mcgen('''
209    default:
210        error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
211                   "%(name)s");
212    }
213    visit_end_alternate(v);
214    if (err && visit_is_input(v)) {
215        qapi_free_%(c_name)s(*obj);
216        *obj = NULL;
217    }
218out:
219    error_propagate(errp, err);
220}
221''',
222                 name=name, c_name=c_name(name))
223
224    return ret
225
226
227def gen_visit_object(name, base, members, variants):
228    return mcgen('''
229
230void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
231{
232    Error *err = NULL;
233
234    visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
235    if (err) {
236        goto out;
237    }
238    if (!*obj) {
239        goto out_obj;
240    }
241    visit_type_%(c_name)s_members(v, *obj, &err);
242    if (err) {
243        goto out_obj;
244    }
245    visit_check_struct(v, &err);
246out_obj:
247    visit_end_struct(v);
248    if (err && visit_is_input(v)) {
249        qapi_free_%(c_name)s(*obj);
250        *obj = NULL;
251    }
252out:
253    error_propagate(errp, err);
254}
255''',
256                 c_name=c_name(name))
257
258
259class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
260    def __init__(self):
261        self.decl = None
262        self.defn = None
263        self._btin = None
264
265    def visit_begin(self, schema):
266        self.decl = ''
267        self.defn = ''
268        self._btin = guardstart('QAPI_VISIT_BUILTIN')
269
270    def visit_end(self):
271        # To avoid header dependency hell, we always generate
272        # declarations for built-in types in our header files and
273        # simply guard them.  See also do_builtins (command line
274        # option -b).
275        self._btin += guardend('QAPI_VISIT_BUILTIN')
276        self.decl = self._btin + self.decl
277        self._btin = None
278
279    def visit_enum_type(self, name, info, values, prefix):
280        # Special case for our lone builtin enum type
281        # TODO use something cleaner than existence of info
282        if not info:
283            self._btin += gen_visit_decl(name, scalar=True)
284            if do_builtins:
285                self.defn += gen_visit_enum(name)
286        else:
287            self.decl += gen_visit_decl(name, scalar=True)
288            self.defn += gen_visit_enum(name)
289
290    def visit_array_type(self, name, info, element_type):
291        decl = gen_visit_decl(name)
292        defn = gen_visit_list(name, element_type)
293        if isinstance(element_type, QAPISchemaBuiltinType):
294            self._btin += decl
295            if do_builtins:
296                self.defn += defn
297        else:
298            self.decl += decl
299            self.defn += defn
300
301    def visit_object_type(self, name, info, base, members, variants):
302        # Nothing to do for the special empty builtin
303        if name == 'q_empty':
304            return
305        self.decl += gen_visit_members_decl(name)
306        self.defn += gen_visit_object_members(name, base, members, variants)
307        # TODO Worth changing the visitor signature, so we could
308        # directly use rather than repeat type.is_implicit()?
309        if not name.startswith('q_'):
310            # only explicit types need an allocating visit
311            self.decl += gen_visit_decl(name)
312            self.defn += gen_visit_object(name, base, members, variants)
313
314    def visit_alternate_type(self, name, info, variants):
315        self.decl += gen_visit_decl(name)
316        self.defn += gen_visit_alternate(name, variants)
317
318# If you link code generated from multiple schemata, you want only one
319# instance of the code for built-in types.  Generate it only when
320# do_builtins, enabled by command line option -b.  See also
321# QAPISchemaGenVisitVisitor.visit_end().
322do_builtins = False
323
324(input_file, output_dir, do_c, do_h, prefix, opts) = \
325    parse_command_line("b", ["builtins"])
326
327for o, a in opts:
328    if o in ("-b", "--builtins"):
329        do_builtins = True
330
331c_comment = '''
332/*
333 * schema-defined QAPI visitor functions
334 *
335 * Copyright IBM, Corp. 2011
336 *
337 * Authors:
338 *  Anthony Liguori   <aliguori@us.ibm.com>
339 *
340 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
341 * See the COPYING.LIB file in the top-level directory.
342 *
343 */
344'''
345h_comment = '''
346/*
347 * schema-defined QAPI visitor functions
348 *
349 * Copyright IBM, Corp. 2011
350 *
351 * Authors:
352 *  Anthony Liguori   <aliguori@us.ibm.com>
353 *
354 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
355 * See the COPYING.LIB file in the top-level directory.
356 *
357 */
358'''
359
360(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
361                            'qapi-visit.c', 'qapi-visit.h',
362                            c_comment, h_comment)
363
364fdef.write(mcgen('''
365#include "qemu/osdep.h"
366#include "qemu-common.h"
367#include "qapi/error.h"
368#include "%(prefix)sqapi-visit.h"
369''',
370                 prefix=prefix))
371
372fdecl.write(mcgen('''
373#include "qapi/visitor.h"
374#include "qapi/qmp/qerror.h"
375#include "%(prefix)sqapi-types.h"
376
377''',
378                  prefix=prefix))
379
380schema = QAPISchema(input_file)
381gen = QAPISchemaGenVisitVisitor()
382schema.visit(gen)
383fdef.write(gen.defn)
384fdecl.write(gen.decl)
385
386close_output(fdef, fdecl)
387