xref: /openbmc/qemu/scripts/qapi/commands.py (revision 542b10bd) 
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            assert not memb.ifcond.is_present()
70            if memb.need_has():
71                argstr += 'arg.has_%s, ' % c_name(memb.name)
72            argstr += 'arg.%s, ' % c_name(memb.name)
73
74    lhs = ''
75    if ret_type:
76        lhs = 'retval = '
77
78    name = c_name(name)
79    upper = name.upper()
80
81    if gen_tracing:
82        ret += mcgen('''
83
84    if (trace_event_get_state_backends(TRACE_QMP_ENTER_%(upper)s)) {
85        g_autoptr(GString) req_json = qobject_to_json(QOBJECT(args));
86
87        trace_qmp_enter_%(name)s(req_json->str);
88    }
89''',
90                     upper=upper, name=name)
91
92    ret += mcgen('''
93
94    %(lhs)sqmp_%(name)s(%(args)s&err);
95''',
96                 name=name, args=argstr, lhs=lhs)
97
98    ret += mcgen('''
99    if (err) {
100''')
101
102    if gen_tracing:
103        ret += mcgen('''
104        trace_qmp_exit_%(name)s(error_get_pretty(err), false);
105''',
106                     name=name)
107
108    ret += mcgen('''
109        error_propagate(errp, err);
110        goto out;
111    }
112''')
113
114    if ret_type:
115        ret += mcgen('''
116
117    qmp_marshal_output_%(c_name)s(retval, ret, errp);
118''',
119                     c_name=ret_type.c_name())
120
121    if gen_tracing:
122        if ret_type:
123            ret += mcgen('''
124
125    if (trace_event_get_state_backends(TRACE_QMP_EXIT_%(upper)s)) {
126        g_autoptr(GString) ret_json = qobject_to_json(*ret);
127
128        trace_qmp_exit_%(name)s(ret_json->str, true);
129    }
130''',
131                         upper=upper, name=name)
132        else:
133            ret += mcgen('''
134
135    trace_qmp_exit_%(name)s("{}", true);
136''',
137                         name=name)
138
139    return ret
140
141
142def gen_marshal_output(ret_type: QAPISchemaType) -> str:
143    return mcgen('''
144
145static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
146                                QObject **ret_out, Error **errp)
147{
148    Visitor *v;
149
150    v = qobject_output_visitor_new_qmp(ret_out);
151    if (visit_type_%(c_name)s(v, "unused", &ret_in, errp)) {
152        visit_complete(v, ret_out);
153    }
154    visit_free(v);
155    v = qapi_dealloc_visitor_new();
156    visit_type_%(c_name)s(v, "unused", &ret_in, NULL);
157    visit_free(v);
158}
159''',
160                 c_type=ret_type.c_type(), c_name=ret_type.c_name())
161
162
163def build_marshal_proto(name: str,
164                        coroutine: bool) -> str:
165    return ('void %(coroutine_fn)sqmp_marshal_%(c_name)s(%(params)s)' % {
166        'coroutine_fn': 'coroutine_fn ' if coroutine else '',
167        'c_name': c_name(name),
168        'params': 'QDict *args, QObject **ret, Error **errp',
169    })
170
171
172def gen_marshal_decl(name: str,
173                     coroutine: bool) -> str:
174    return mcgen('''
175%(proto)s;
176''',
177                 proto=build_marshal_proto(name, coroutine))
178
179
180def gen_trace(name: str) -> str:
181    return mcgen('''
182qmp_enter_%(name)s(const char *json) "%%s"
183qmp_exit_%(name)s(const char *result, bool succeeded) "%%s %%d"
184''',
185                 name=c_name(name))
186
187
188def gen_marshal(name: str,
189                arg_type: Optional[QAPISchemaObjectType],
190                boxed: bool,
191                ret_type: Optional[QAPISchemaType],
192                gen_tracing: bool,
193                coroutine: bool) -> str:
194    have_args = boxed or (arg_type and not arg_type.is_empty())
195    if have_args:
196        assert arg_type is not None
197        arg_type_c_name = arg_type.c_name()
198
199    ret = mcgen('''
200
201%(proto)s
202{
203    Error *err = NULL;
204    bool ok = false;
205    Visitor *v;
206''',
207                proto=build_marshal_proto(name, coroutine))
208
209    if ret_type:
210        ret += mcgen('''
211    %(c_type)s retval;
212''',
213                     c_type=ret_type.c_type())
214
215    if have_args:
216        ret += mcgen('''
217    %(c_name)s arg = {0};
218''',
219                     c_name=arg_type_c_name)
220
221    ret += mcgen('''
222
223    v = qobject_input_visitor_new_qmp(QOBJECT(args));
224    if (!visit_start_struct(v, NULL, NULL, 0, errp)) {
225        goto out;
226    }
227''')
228
229    if have_args:
230        ret += mcgen('''
231    if (visit_type_%(c_arg_type)s_members(v, &arg, errp)) {
232        ok = visit_check_struct(v, errp);
233    }
234''',
235                     c_arg_type=arg_type_c_name)
236    else:
237        ret += mcgen('''
238    ok = visit_check_struct(v, errp);
239''')
240
241    ret += mcgen('''
242    visit_end_struct(v, NULL);
243    if (!ok) {
244        goto out;
245    }
246''')
247
248    ret += gen_call(name, arg_type, boxed, ret_type, gen_tracing)
249
250    ret += mcgen('''
251
252out:
253    visit_free(v);
254''')
255
256    ret += mcgen('''
257    v = qapi_dealloc_visitor_new();
258    visit_start_struct(v, NULL, NULL, 0, NULL);
259''')
260
261    if have_args:
262        ret += mcgen('''
263    visit_type_%(c_arg_type)s_members(v, &arg, NULL);
264''',
265                     c_arg_type=arg_type_c_name)
266
267    ret += mcgen('''
268    visit_end_struct(v, NULL);
269    visit_free(v);
270''')
271
272    ret += mcgen('''
273}
274''')
275    return ret
276
277
278def gen_register_command(name: str,
279                         features: List[QAPISchemaFeature],
280                         success_response: bool,
281                         allow_oob: bool,
282                         allow_preconfig: bool,
283                         coroutine: bool) -> str:
284    options = []
285
286    if not success_response:
287        options += ['QCO_NO_SUCCESS_RESP']
288    if allow_oob:
289        options += ['QCO_ALLOW_OOB']
290    if allow_preconfig:
291        options += ['QCO_ALLOW_PRECONFIG']
292    if coroutine:
293        options += ['QCO_COROUTINE']
294
295    ret = mcgen('''
296    qmp_register_command(cmds, "%(name)s",
297                         qmp_marshal_%(c_name)s, %(opts)s, %(feats)s);
298''',
299                name=name, c_name=c_name(name),
300                opts=' | '.join(options) or 0,
301                feats=gen_special_features(features))
302    return ret
303
304
305class QAPISchemaGenCommandVisitor(QAPISchemaModularCVisitor):
306    def __init__(self, prefix: str, gen_tracing: bool):
307        super().__init__(
308            prefix, 'qapi-commands',
309            ' * Schema-defined QAPI/QMP commands', None, __doc__,
310            gen_tracing=gen_tracing)
311        self._visited_ret_types: Dict[QAPIGenC, Set[QAPISchemaType]] = {}
312        self._gen_tracing = gen_tracing
313
314    def _begin_user_module(self, name: str) -> None:
315        self._visited_ret_types[self._genc] = set()
316        commands = self._module_basename('qapi-commands', name)
317        types = self._module_basename('qapi-types', name)
318        visit = self._module_basename('qapi-visit', name)
319        self._genc.add(mcgen('''
320#include "qemu/osdep.h"
321#include "qapi/compat-policy.h"
322#include "qapi/visitor.h"
323#include "qapi/qmp/qdict.h"
324#include "qapi/dealloc-visitor.h"
325#include "qapi/error.h"
326#include "%(visit)s.h"
327#include "%(commands)s.h"
328''',
329                             commands=commands, visit=visit))
330
331        if self._gen_tracing and commands != 'qapi-commands':
332            self._genc.add(mcgen('''
333#include "qapi/qmp/qjson.h"
334#include "trace/trace-%(nm)s_trace_events.h"
335''',
336                                 nm=c_name(commands, protect=False)))
337            # We use c_name(commands, protect=False) to turn '-' into '_', to
338            # match .underscorify() in trace/meson.build
339
340        self._genh.add(mcgen('''
341#include "%(types)s.h"
342
343''',
344                             types=types))
345
346    def visit_begin(self, schema: QAPISchema) -> None:
347        self._add_module('./init', ' * QAPI Commands initialization')
348        self._genh.add(mcgen('''
349#include "qapi/qmp/dispatch.h"
350
351void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
352''',
353                             c_prefix=c_name(self._prefix, protect=False)))
354        self._genc.add(mcgen('''
355#include "qemu/osdep.h"
356#include "%(prefix)sqapi-commands.h"
357#include "%(prefix)sqapi-init-commands.h"
358
359void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds)
360{
361    QTAILQ_INIT(cmds);
362
363''',
364                             prefix=self._prefix,
365                             c_prefix=c_name(self._prefix, protect=False)))
366
367    def visit_end(self) -> None:
368        with self._temp_module('./init'):
369            self._genc.add(mcgen('''
370}
371'''))
372
373    def visit_command(self,
374                      name: str,
375                      info: Optional[QAPISourceInfo],
376                      ifcond: QAPISchemaIfCond,
377                      features: List[QAPISchemaFeature],
378                      arg_type: Optional[QAPISchemaObjectType],
379                      ret_type: Optional[QAPISchemaType],
380                      gen: bool,
381                      success_response: bool,
382                      boxed: bool,
383                      allow_oob: bool,
384                      allow_preconfig: bool,
385                      coroutine: bool) -> None:
386        if not gen:
387            return
388        # FIXME: If T is a user-defined type, the user is responsible
389        # for making this work, i.e. to make T's condition the
390        # conjunction of the T-returning commands' conditions.  If T
391        # is a built-in type, this isn't possible: the
392        # qmp_marshal_output_T() will be generated unconditionally.
393        if ret_type and ret_type not in self._visited_ret_types[self._genc]:
394            self._visited_ret_types[self._genc].add(ret_type)
395            with ifcontext(ret_type.ifcond,
396                           self._genh, self._genc):
397                self._genc.add(gen_marshal_output(ret_type))
398        with ifcontext(ifcond, self._genh, self._genc):
399            self._genh.add(gen_command_decl(name, arg_type, boxed,
400                                            ret_type, coroutine))
401            self._genh.add(gen_marshal_decl(name, coroutine))
402            self._genc.add(gen_marshal(name, arg_type, boxed, ret_type,
403                                       self._gen_tracing, coroutine))
404            if self._gen_tracing:
405                self._gen_trace_events.add(gen_trace(name))
406        with self._temp_module('./init'):
407            with ifcontext(ifcond, self._genh, self._genc):
408                self._genc.add(gen_register_command(
409                    name, features, success_response, allow_oob,
410                    allow_preconfig, coroutine))
411
412
413def gen_commands(schema: QAPISchema,
414                 output_dir: str,
415                 prefix: str,
416                 gen_tracing: bool) -> None:
417    vis = QAPISchemaGenCommandVisitor(prefix, gen_tracing)
418    schema.visit(vis)
419    vis.write(output_dir)
420