xref: /qemu/scripts/qapi/visit.py (revision 60390d2dc85ffade8981ca41e02335cb07353a6d) 
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 *
16
17
18def gen_visit_decl(name, scalar=False):
19    c_type = c_name(name) + ' *'
20    if not scalar:
21        c_type += '*'
22    return mcgen('''
23void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
24''',
25                 c_name=c_name(name), c_type=c_type)
26
27
28def gen_visit_members_decl(name):
29    return mcgen('''
30
31void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
32''',
33                 c_name=c_name(name))
34
35
36def gen_visit_object_members(name, base, members, variants):
37    ret = mcgen('''
38
39void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
40{
41    Error *err = NULL;
42
43''',
44                c_name=c_name(name))
45
46    if base:
47        ret += mcgen('''
48    visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, &err);
49    if (err) {
50        goto out;
51    }
52''',
53                     c_type=base.c_name())
54
55    for memb in members:
56        if memb.optional:
57            ret += mcgen('''
58    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
59''',
60                         name=memb.name, c_name=c_name(memb.name))
61            push_indent()
62        ret += mcgen('''
63    visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, &err);
64    if (err) {
65        goto out;
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
76    if variants:
77        ret += mcgen('''
78    switch (obj->%(c_name)s) {
79''',
80                     c_name=c_name(variants.tag_member.name))
81
82        for var in variants.variants:
83            ret += mcgen('''
84    case %(case)s:
85        visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, &err);
86        break;
87''',
88                         case=c_enum_const(variants.tag_member.type.name,
89                                           var.name,
90                                           variants.tag_member.type.prefix),
91                         c_type=var.type.c_name(), c_name=c_name(var.name))
92
93        ret += mcgen('''
94    default:
95        abort();
96    }
97''')
98
99    # 'goto out' produced for base, for each member, and if variants were
100    # present
101    if base or members or variants:
102        ret += mcgen('''
103
104out:
105''')
106    ret += mcgen('''
107    error_propagate(errp, err);
108}
109''')
110    return ret
111
112
113def gen_visit_list(name, element_type):
114    return mcgen('''
115
116void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
117{
118    Error *err = NULL;
119    %(c_name)s *tail;
120    size_t size = sizeof(**obj);
121
122    visit_start_list(v, name, (GenericList **)obj, size, &err);
123    if (err) {
124        goto out;
125    }
126
127    for (tail = *obj; tail;
128         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
129        visit_type_%(c_elt_type)s(v, NULL, &tail->value, &err);
130        if (err) {
131            break;
132        }
133    }
134
135    if (!err) {
136        visit_check_list(v, &err);
137    }
138    visit_end_list(v, (void **)obj);
139    if (err && visit_is_input(v)) {
140        qapi_free_%(c_name)s(*obj);
141        *obj = NULL;
142    }
143out:
144    error_propagate(errp, err);
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
153void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
154{
155    int value = *obj;
156    visit_type_enum(v, name, &value, %(c_name)s_lookup, errp);
157    *obj = value;
158}
159''',
160                 c_name=c_name(name))
161
162
163def gen_visit_alternate(name, variants):
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                          &err);
172    if (err) {
173        goto out;
174    }
175    if (!*obj) {
176        goto out_obj;
177    }
178    switch ((*obj)->type) {
179''',
180                 c_name=c_name(name))
181
182    for var in variants.variants:
183        ret += mcgen('''
184    case %(case)s:
185''',
186                     case=var.type.alternate_qtype())
187        if isinstance(var.type, QAPISchemaObjectType):
188            ret += mcgen('''
189        visit_start_struct(v, name, NULL, 0, &err);
190        if (err) {
191            break;
192        }
193        visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err);
194        if (!err) {
195            visit_check_struct(v, &err);
196        }
197        visit_end_struct(v, NULL);
198''',
199                         c_type=var.type.c_name(),
200                         c_name=c_name(var.name))
201        else:
202            ret += mcgen('''
203        visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
204''',
205                         c_type=var.type.c_name(),
206                         c_name=c_name(var.name))
207        ret += mcgen('''
208        break;
209''')
210
211    ret += mcgen('''
212    case QTYPE_NONE:
213        abort();
214    default:
215        error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
216                   "%(name)s");
217    }
218out_obj:
219    visit_end_alternate(v, (void **)obj);
220    if (err && visit_is_input(v)) {
221        qapi_free_%(c_name)s(*obj);
222        *obj = NULL;
223    }
224out:
225    error_propagate(errp, err);
226}
227''',
228                 name=name, c_name=c_name(name))
229
230    return ret
231
232
233def gen_visit_object(name, base, members, variants):
234    return mcgen('''
235
236void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
237{
238    Error *err = NULL;
239
240    visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), &err);
241    if (err) {
242        goto out;
243    }
244    if (!*obj) {
245        goto out_obj;
246    }
247    visit_type_%(c_name)s_members(v, *obj, &err);
248    if (err) {
249        goto out_obj;
250    }
251    visit_check_struct(v, &err);
252out_obj:
253    visit_end_struct(v, (void **)obj);
254    if (err && visit_is_input(v)) {
255        qapi_free_%(c_name)s(*obj);
256        *obj = NULL;
257    }
258out:
259    error_propagate(errp, err);
260}
261''',
262                 c_name=c_name(name))
263
264
265class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
266    def __init__(self):
267        self.decl = None
268        self.defn = None
269        self._btin = None
270
271    def visit_begin(self, schema):
272        self.decl = ''
273        self.defn = ''
274        self._btin = guardstart('QAPI_VISIT_BUILTIN')
275
276    def visit_end(self):
277        # To avoid header dependency hell, we always generate
278        # declarations for built-in types in our header files and
279        # simply guard them.  See also do_builtins (command line
280        # option -b).
281        self._btin += guardend('QAPI_VISIT_BUILTIN')
282        self.decl = self._btin + self.decl
283        self._btin = None
284
285    def visit_enum_type(self, name, info, values, prefix):
286        # Special case for our lone builtin enum type
287        # TODO use something cleaner than existence of info
288        if not info:
289            self._btin += gen_visit_decl(name, scalar=True)
290            if do_builtins:
291                self.defn += gen_visit_enum(name)
292        else:
293            self.decl += gen_visit_decl(name, scalar=True)
294            self.defn += gen_visit_enum(name)
295
296    def visit_array_type(self, name, info, element_type):
297        decl = gen_visit_decl(name)
298        defn = gen_visit_list(name, element_type)
299        if isinstance(element_type, QAPISchemaBuiltinType):
300            self._btin += decl
301            if do_builtins:
302                self.defn += defn
303        else:
304            self.decl += decl
305            self.defn += defn
306
307    def visit_object_type(self, name, info, base, members, variants):
308        # Nothing to do for the special empty builtin
309        if name == 'q_empty':
310            return
311        self.decl += gen_visit_members_decl(name)
312        self.defn += gen_visit_object_members(name, base, members, variants)
313        # TODO Worth changing the visitor signature, so we could
314        # directly use rather than repeat type.is_implicit()?
315        if not name.startswith('q_'):
316            # only explicit types need an allocating visit
317            self.decl += gen_visit_decl(name)
318            self.defn += gen_visit_object(name, base, members, variants)
319
320    def visit_alternate_type(self, name, info, variants):
321        self.decl += gen_visit_decl(name)
322        self.defn += gen_visit_alternate(name, variants)
323
324# If you link code generated from multiple schemata, you want only one
325# instance of the code for built-in types.  Generate it only when
326# do_builtins, enabled by command line option -b.  See also
327# QAPISchemaGenVisitVisitor.visit_end().
328do_builtins = False
329
330(input_file, output_dir, do_c, do_h, prefix, opts) = \
331    parse_command_line('b', ['builtins'])
332
333for o, a in opts:
334    if o in ('-b', '--builtins'):
335        do_builtins = True
336
337c_comment = '''
338/*
339 * schema-defined QAPI visitor functions
340 *
341 * Copyright IBM, Corp. 2011
342 *
343 * Authors:
344 *  Anthony Liguori   <aliguori@us.ibm.com>
345 *
346 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
347 * See the COPYING.LIB file in the top-level directory.
348 *
349 */
350'''
351h_comment = '''
352/*
353 * schema-defined QAPI visitor functions
354 *
355 * Copyright IBM, Corp. 2011
356 *
357 * Authors:
358 *  Anthony Liguori   <aliguori@us.ibm.com>
359 *
360 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
361 * See the COPYING.LIB file in the top-level directory.
362 *
363 */
364'''
365
366(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
367                            'qapi-visit.c', 'qapi-visit.h',
368                            c_comment, h_comment)
369
370fdef.write(mcgen('''
371#include "qemu/osdep.h"
372#include "qemu-common.h"
373#include "qapi/error.h"
374#include "%(prefix)sqapi-visit.h"
375''',
376                 prefix=prefix))
377
378fdecl.write(mcgen('''
379#include "qapi/visitor.h"
380#include "qapi/qmp/qerror.h"
381#include "%(prefix)sqapi-types.h"
382
383''',
384                  prefix=prefix))
385
386schema = QAPISchema(input_file)
387gen = QAPISchemaGenVisitVisitor()
388schema.visit(gen)
389fdef.write(gen.defn)
390fdecl.write(gen.decl)
391
392close_output(fdef, fdecl)
393