xref: /qemu/scripts/qapi/commands.py (revision 1dd91b22) 
1"""
2QAPI command marshaller 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 typing import (
17    Dict,
18    List,
19    Optional,
20    Set,
21)
22
23from .common import c_name, mcgen
24from .gen import (
25    QAPIGenC,
26    QAPISchemaModularCVisitor,
27    build_params,
28    gen_special_features,
29    ifcontext,
30)
31from .schema import (
32    QAPISchema,
33    QAPISchemaFeature,
34    QAPISchemaIfCond,
35    QAPISchemaObjectType,
36    QAPISchemaType,
37)
38from .source import QAPISourceInfo
39
40
41def gen_command_decl(name: str,
42                     arg_type: Optional[QAPISchemaObjectType],
43                     boxed: bool,
44                     ret_type: Optional[QAPISchemaType],
45                     coroutine: bool) -> str:
46    return mcgen('''
47%(c_type)s %(coroutine_fn)sqmp_%(c_name)s(%(params)s);
48''',
49                 c_type=(ret_type and ret_type.c_type()) or 'void',
50                 coroutine_fn='coroutine_fn ' if coroutine else '',
51                 c_name=c_name(name),
52                 params=build_params(arg_type, boxed, 'Error **errp'))
53
54
55def gen_call(name: str,
56             arg_type: Optional[QAPISchemaObjectType],
57             boxed: bool,
58             ret_type: Optional[QAPISchemaType],
59             gen_tracing: bool) -> str:
60    ret = ''
61
62    argstr = ''
63    if boxed:
64        assert arg_type
65        argstr = '&arg, '
66    elif arg_type:
67        assert not arg_type.variants
68        for memb in arg_type.members:
69            if memb.need_has():
70                argstr += 'arg.has_%s, ' % c_name(memb.name)
71            argstr += 'arg.%s, ' % c_name(memb.name)
72
73    lhs = ''
74    if ret_type:
75        lhs = 'retval = '
76
77    name = c_name(name)
78    upper = name.upper()
79
80    if gen_tracing:
81        ret += mcgen('''
82
83    if (trace_event_get_state_backends(TRACE_QMP_ENTER_%(upper)s)) {
84        g_autoptr(GString) req_json = qobject_to_json(QOBJECT(args));
85
86        trace_qmp_enter_%(name)s(req_json->str);
87    }
88''',
89                     upper=upper, name=name)
90
91    ret += mcgen('''
92
93    %(lhs)sqmp_%(name)s(%(args)s&err);
94''',
95                 name=name, args=argstr, lhs=lhs)
96
97    ret += mcgen('''
98    if (err) {
99''')
100
101    if gen_tracing:
102        ret += mcgen('''
103        trace_qmp_exit_%(name)s(error_get_pretty(err), false);
104''',
105                     name=name)
106
107    ret += mcgen('''
108        error_propagate(errp, err);
109        goto out;
110    }
111''')
112
113    if ret_type:
114        ret += mcgen('''
115
116    qmp_marshal_output_%(c_name)s(retval, ret, errp);
117''',
118                     c_name=ret_type.c_name())
119
120    if gen_tracing:
121        if ret_type:
122            ret += mcgen('''
123
124    if (trace_event_get_state_backends(TRACE_QMP_EXIT_%(upper)s)) {
125        g_autoptr(GString) ret_json = qobject_to_json(*ret);
126
127        trace_qmp_exit_%(name)s(ret_json->str, true);
128    }
129''',
130                         upper=upper, name=name)
131        else:
132            ret += mcgen('''
133
134    trace_qmp_exit_%(name)s("{}", true);
135''',
136                         name=name)
137
138    return ret
139
140
141def gen_marshal_output(ret_type: QAPISchemaType) -> str:
142    return mcgen('''
143
144static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
145                                QObject **ret_out, Error **errp)
146{
147    Visitor *v;
148
149    v = qobject_output_visitor_new_qmp(ret_out);
150    if (visit_type_%(c_name)s(v, "unused", &ret_in, errp)) {
151        visit_complete(v, ret_out);
152    }
153    visit_free(v);
154    v = qapi_dealloc_visitor_new();
155    visit_type_%(c_name)s(v, "unused", &ret_in, NULL);
156    visit_free(v);
157}
158''',
159                 c_type=ret_type.c_type(), c_name=ret_type.c_name())
160
161
162def build_marshal_proto(name: str,
163                        coroutine: bool) -> str:
164    return ('void %(coroutine_fn)sqmp_marshal_%(c_name)s(%(params)s)' % {
165        'coroutine_fn': 'coroutine_fn ' if coroutine else '',
166        'c_name': c_name(name),
167        'params': 'QDict *args, QObject **ret, Error **errp',
168    })
169
170
171def gen_marshal_decl(name: str,
172                     coroutine: bool) -> str:
173    return mcgen('''
174%(proto)s;
175''',
176                 proto=build_marshal_proto(name, coroutine))
177
178
179def gen_trace(name: str) -> str:
180    return mcgen('''
181qmp_enter_%(name)s(const char *json) "%%s"
182qmp_exit_%(name)s(const char *result, bool succeeded) "%%s %%d"
183''',
184                 name=c_name(name))
185
186
187def gen_marshal(name: str,
188                arg_type: Optional[QAPISchemaObjectType],
189                boxed: bool,
190                ret_type: Optional[QAPISchemaType],
191                gen_tracing: bool,
192                coroutine: bool) -> str:
193    have_args = boxed or (arg_type and not arg_type.is_empty())
194    if have_args:
195        assert arg_type is not None
196        arg_type_c_name = arg_type.c_name()
197
198    ret = mcgen('''
199
200%(proto)s
201{
202    Error *err = NULL;
203    bool ok = false;
204    Visitor *v;
205''',
206                proto=build_marshal_proto(name, coroutine))
207
208    if ret_type:
209        ret += mcgen('''
210    %(c_type)s retval;
211''',
212                     c_type=ret_type.c_type())
213
214    if have_args:
215        ret += mcgen('''
216    %(c_name)s arg = {0};
217''',
218                     c_name=arg_type_c_name)
219
220    ret += mcgen('''
221
222    v = qobject_input_visitor_new_qmp(QOBJECT(args));
223    if (!visit_start_struct(v, NULL, NULL, 0, errp)) {
224        goto out;
225    }
226''')
227
228    if have_args:
229        ret += mcgen('''
230    if (visit_type_%(c_arg_type)s_members(v, &arg, errp)) {
231        ok = visit_check_struct(v, errp);
232    }
233''',
234                     c_arg_type=arg_type_c_name)
235    else:
236        ret += mcgen('''
237    ok = visit_check_struct(v, errp);
238''')
239
240    ret += mcgen('''
241    visit_end_struct(v, NULL);
242    if (!ok) {
243        goto out;
244    }
245''')
246
247    ret += gen_call(name, arg_type, boxed, ret_type, gen_tracing)
248
249    ret += mcgen('''
250
251out:
252    visit_free(v);
253''')
254
255    ret += mcgen('''
256    v = qapi_dealloc_visitor_new();
257    visit_start_struct(v, NULL, NULL, 0, NULL);
258''')
259
260    if have_args:
261        ret += mcgen('''
262    visit_type_%(c_arg_type)s_members(v, &arg, NULL);
263''',
264                     c_arg_type=arg_type_c_name)
265
266    ret += mcgen('''
267    visit_end_struct(v, NULL);
268    visit_free(v);
269''')
270
271    ret += mcgen('''
272}
273''')
274    return ret
275
276
277def gen_register_command(name: str,
278                         features: List[QAPISchemaFeature],
279                         success_response: bool,
280                         allow_oob: bool,
281                         allow_preconfig: bool,
282                         coroutine: bool) -> str:
283    options = []
284
285    if not success_response:
286        options += ['QCO_NO_SUCCESS_RESP']
287    if allow_oob:
288        options += ['QCO_ALLOW_OOB']
289    if allow_preconfig:
290        options += ['QCO_ALLOW_PRECONFIG']
291    if coroutine:
292        options += ['QCO_COROUTINE']
293
294    ret = mcgen('''
295    qmp_register_command(cmds, "%(name)s",
296                         qmp_marshal_%(c_name)s, %(opts)s, %(feats)s);
297''',
298                name=name, c_name=c_name(name),
299                opts=' | '.join(options) or 0,
300                feats=gen_special_features(features))
301    return ret
302
303
304class QAPISchemaGenCommandVisitor(QAPISchemaModularCVisitor):
305    def __init__(self, prefix: str, gen_tracing: bool):
306        super().__init__(
307            prefix, 'qapi-commands',
308            ' * Schema-defined QAPI/QMP commands', None, __doc__,
309            gen_tracing=gen_tracing)
310        self._visited_ret_types: Dict[QAPIGenC, Set[QAPISchemaType]] = {}
311        self._gen_tracing = gen_tracing
312
313    def _begin_user_module(self, name: str) -> None:
314        self._visited_ret_types[self._genc] = set()
315        commands = self._module_basename('qapi-commands', name)
316        types = self._module_basename('qapi-types', name)
317        visit = self._module_basename('qapi-visit', name)
318        self._genc.add(mcgen('''
319#include "qemu/osdep.h"
320#include "qapi/compat-policy.h"
321#include "qapi/visitor.h"
322#include "qapi/qmp/qdict.h"
323#include "qapi/dealloc-visitor.h"
324#include "qapi/error.h"
325#include "%(visit)s.h"
326#include "%(commands)s.h"
327''',
328                             commands=commands, visit=visit))
329
330        if self._gen_tracing and commands != 'qapi-commands':
331            self._genc.add(mcgen('''
332#include "qapi/qmp/qjson.h"
333#include "trace/trace-%(nm)s_trace_events.h"
334''',
335                                 nm=c_name(commands, protect=False)))
336            # We use c_name(commands, protect=False) to turn '-' into '_', to
337            # match .underscorify() in trace/meson.build
338
339        self._genh.add(mcgen('''
340#include "%(types)s.h"
341
342''',
343                             types=types))
344
345    def visit_begin(self, schema: QAPISchema) -> None:
346        self._add_module('./init', ' * QAPI Commands initialization')
347        self._genh.add(mcgen('''
348#include "qapi/qmp/dispatch.h"
349
350void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
351''',
352                             c_prefix=c_name(self._prefix, protect=False)))
353        self._genc.add(mcgen('''
354#include "qemu/osdep.h"
355#include "%(prefix)sqapi-commands.h"
356#include "%(prefix)sqapi-init-commands.h"
357
358void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds)
359{
360    QTAILQ_INIT(cmds);
361
362''',
363                             prefix=self._prefix,
364                             c_prefix=c_name(self._prefix, protect=False)))
365
366    def visit_end(self) -> None:
367        with self._temp_module('./init'):
368            self._genc.add(mcgen('''
369}
370'''))
371
372    def visit_command(self,
373                      name: str,
374                      info: Optional[QAPISourceInfo],
375                      ifcond: QAPISchemaIfCond,
376                      features: List[QAPISchemaFeature],
377                      arg_type: Optional[QAPISchemaObjectType],
378                      ret_type: Optional[QAPISchemaType],
379                      gen: bool,
380                      success_response: bool,
381                      boxed: bool,
382                      allow_oob: bool,
383                      allow_preconfig: bool,
384                      coroutine: bool) -> None:
385        if not gen:
386            return
387        # FIXME: If T is a user-defined type, the user is responsible
388        # for making this work, i.e. to make T's condition the
389        # conjunction of the T-returning commands' conditions.  If T
390        # is a built-in type, this isn't possible: the
391        # qmp_marshal_output_T() will be generated unconditionally.
392        if ret_type and ret_type not in self._visited_ret_types[self._genc]:
393            self._visited_ret_types[self._genc].add(ret_type)
394            with ifcontext(ret_type.ifcond,
395                           self._genh, self._genc):
396                self._genc.add(gen_marshal_output(ret_type))
397        with ifcontext(ifcond, self._genh, self._genc):
398            self._genh.add(gen_command_decl(name, arg_type, boxed,
399                                            ret_type, coroutine))
400            self._genh.add(gen_marshal_decl(name, coroutine))
401            self._genc.add(gen_marshal(name, arg_type, boxed, ret_type,
402                                       self._gen_tracing, coroutine))
403            if self._gen_tracing:
404                self._gen_trace_events.add(gen_trace(name))
405        with self._temp_module('./init'):
406            with ifcontext(ifcond, self._genh, self._genc):
407                self._genc.add(gen_register_command(
408                    name, features, success_response, allow_oob,
409                    allow_preconfig, coroutine))
410
411
412def gen_commands(schema: QAPISchema,
413                 output_dir: str,
414                 prefix: str,
415                 gen_tracing: bool) -> None:
416    vis = QAPISchemaGenCommandVisitor(prefix, gen_tracing)
417    schema.visit(vis)
418    vis.write(output_dir)
419