From 15c2f669e3fb2bc97f7b42d1871f595c0ac24af8 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Thu, 28 Apr 2016 15:45:27 -0600 Subject: [PATCH] qapi: Split visit_end_struct() into pieces As mentioned in previous patches, we want to call visit_end_struct() functions unconditionally, so that visitors can release resources tied up since the matching visit_start_struct() without also having to worry about error priority if more than one error occurs. Even though error_propagate() can be safely used to ignore a second error during cleanup caused by a first error, it is simpler if the cleanup cannot set an error. So, split out the error checking portion (basically, input visitors checking for unvisited keys) into a new function visit_check_struct(), which can be safely skipped if any earlier errors are encountered, and leave the cleanup portion (which never fails, but must be called unconditionally if visit_start_struct() succeeded) in visit_end_struct(). Generated code in qapi-visit.c has diffs resembling: |@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v, | goto out_obj; | } | visit_type_ACPIOSTInfo_members(v, obj, &err); |- error_propagate(errp, err); |- err = NULL; |+ if (err) { |+ goto out_obj; |+ } |+ visit_check_struct(v, &err); | out_obj: |- visit_end_struct(v, &err); |+ visit_end_struct(v); | out: and in qapi-event.c: @@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP | goto out; | } | visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, ¶m, &err); |- visit_end_struct(v, err ? NULL : &err); |+ if (!err) { |+ visit_check_struct(v, &err); |+ } |+ visit_end_struct(v); | if (err) { | goto out; Signed-off-by: Eric Blake Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com> [Conflict with a doc fixup resolved] Signed-off-by: Markus Armbruster --- block/crypto.c | 14 ++++++++------ docs/qapi-code-gen.txt | 15 ++++++++++----- hw/ppc/spapr_drc.c | 3 ++- hw/virtio/virtio-balloon.c | 15 ++++++++------- include/qapi/visitor-impl.h | 5 ++++- include/qapi/visitor.h | 21 ++++++++++++++++----- qapi/opts-visitor.c | 17 +++++++++++++++-- qapi/qapi-dealloc-visitor.c | 2 +- qapi/qapi-visit-core.c | 11 +++++++++-- qapi/qmp-input-visitor.c | 35 ++++++++++++++++++++--------------- qapi/qmp-output-visitor.c | 2 +- qom/object.c | 5 ++--- qom/object_interfaces.c | 23 ++++++++++------------- scripts/qapi-commands.py | 7 +++++-- scripts/qapi-event.py | 5 ++++- scripts/qapi-visit.py | 15 +++++++++------ tests/test-qmp-input-visitor.c | 3 ++- tests/test-qmp-output-visitor.c | 3 ++- 18 files changed, 128 insertions(+), 73 deletions(-) diff --git a/block/crypto.c b/block/crypto.c index 1903e84fbd..2424a4c9c9 100644 --- a/block/crypto.c +++ b/block/crypto.c @@ -196,7 +196,6 @@ block_crypto_open_opts_init(QCryptoBlockFormat format, OptsVisitor *ov; QCryptoBlockOpenOptions *ret = NULL; Error *local_err = NULL; - Error *end_err = NULL; ret = g_new0(QCryptoBlockOpenOptions, 1); ret->format = format; @@ -219,9 +218,11 @@ block_crypto_open_opts_init(QCryptoBlockFormat format, error_setg(&local_err, "Unsupported block format %d", format); break; } + if (!local_err) { + visit_check_struct(opts_get_visitor(ov), &local_err); + } - visit_end_struct(opts_get_visitor(ov), &end_err); - error_propagate(&local_err, end_err); + visit_end_struct(opts_get_visitor(ov)); out: if (local_err) { @@ -242,7 +243,6 @@ block_crypto_create_opts_init(QCryptoBlockFormat format, OptsVisitor *ov; QCryptoBlockCreateOptions *ret = NULL; Error *local_err = NULL; - Error *end_err = NULL; ret = g_new0(QCryptoBlockCreateOptions, 1); ret->format = format; @@ -265,9 +265,11 @@ block_crypto_create_opts_init(QCryptoBlockFormat format, error_setg(&local_err, "Unsupported block format %d", format); break; } + if (!local_err) { + visit_check_struct(opts_get_visitor(ov), &local_err); + } - visit_end_struct(opts_get_visitor(ov), &end_err); - error_propagate(&local_err, end_err); + visit_end_struct(opts_get_visitor(ov)); out: if (local_err) { diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt index b4ae1be3b4..d135847c87 100644 --- a/docs/qapi-code-gen.txt +++ b/docs/qapi-code-gen.txt @@ -899,10 +899,12 @@ Example: goto out_obj; } visit_type_UserDefOne_members(v, *obj, &err); - error_propagate(errp, err); - err = NULL; + if (err) { + goto out_obj; + } + visit_check_struct(v, &err); out_obj: - visit_end_struct(v, &err); + visit_end_struct(v); out: error_propagate(errp, err); } @@ -1007,7 +1009,10 @@ Example: goto out; } visit_type_UserDefOneList(v, "arg1", &arg1, &err); - visit_end_struct(v, err ? NULL : &err); + if (!err) { + visit_check_struct(v, &err); + } + visit_end_struct(v); if (err) { goto out; } @@ -1026,7 +1031,7 @@ Example: v = qapi_dealloc_get_visitor(qdv); visit_start_struct(v, NULL, NULL, 0, NULL); visit_type_UserDefOneList(v, "arg1", &arg1, NULL); - visit_end_struct(v, NULL); + visit_end_struct(v); qapi_dealloc_visitor_cleanup(qdv); } diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c index 480a8c607c..e3a6191ad4 100644 --- a/hw/ppc/spapr_drc.c +++ b/hw/ppc/spapr_drc.c @@ -297,7 +297,8 @@ static void prop_get_fdt(Object *obj, Visitor *v, const char *name, case FDT_END_NODE: /* shouldn't ever see an FDT_END_NODE before FDT_BEGIN_NODE */ g_assert(fdt_depth > 0); - visit_end_struct(v, &err); + visit_check_struct(v, &err); + visit_end_struct(v); if (err) { error_propagate(errp, err); return; diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 9dbe681790..8c15e09470 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -138,17 +138,18 @@ static void balloon_stats_get_all(Object *obj, Visitor *v, const char *name, for (i = 0; i < VIRTIO_BALLOON_S_NR; i++) { visit_type_uint64(v, balloon_stat_names[i], &s->stats[i], &err); if (err) { - break; + goto out_nested; } } - error_propagate(errp, err); - err = NULL; - visit_end_struct(v, &err); + visit_check_struct(v, &err); +out_nested: + visit_end_struct(v); + if (!err) { + visit_check_struct(v, &err); + } out_end: - error_propagate(errp, err); - err = NULL; - visit_end_struct(v, &err); + visit_end_struct(v); out: error_propagate(errp, err); } diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h index 88d27d58de..b20a9226e0 100644 --- a/include/qapi/visitor-impl.h +++ b/include/qapi/visitor-impl.h @@ -43,8 +43,11 @@ struct Visitor void (*start_struct)(Visitor *v, const char *name, void **obj, size_t size, Error **errp); + /* Optional; intended for input visitors */ + void (*check_struct)(Visitor *v, Error **errp); + /* Must be set to visit structs */ - void (*end_struct)(Visitor *v, Error **errp); + void (*end_struct)(Visitor *v); /* Must be set */ void (*start_list)(Visitor *v, const char *name, Error **errp); diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h index 709cca0774..fe268fe78d 100644 --- a/include/qapi/visitor.h +++ b/include/qapi/visitor.h @@ -192,10 +192,11 @@ * } * outlist: * visit_end_list(v); + * if (!err) { + * visit_check_struct(v, &err); + * } * outobj: - * error_propagate(errp, err); - * err = NULL; - * visit_end_struct(v, &err); + * visit_end_struct(v); * out: * error_propagate(errp, err); * ...clean up v... @@ -249,17 +250,27 @@ void visit_start_struct(Visitor *v, const char *name, void **obj, size_t size, Error **errp); /* - * Complete an object visit started earlier. + * Prepare for completing an object visit. * * @errp obeys typical error usage, and reports failures such as * unparsed keys remaining in the input stream. * + * Should be called prior to visit_end_struct() if all other + * intermediate visit steps were successful, to allow the visitor one + * last chance to report errors. May be skipped on a cleanup path, + * where there is no need to check for further errors. + */ +void visit_check_struct(Visitor *v, Error **errp); + +/* + * Complete an object visit started earlier. + * * Must be called after any successful use of visit_start_struct(), * even if intermediate processing was skipped due to errors, to allow * the backend to release any resources. Destroying the visitor early * behaves as if this was implicitly called. */ -void visit_end_struct(Visitor *v, Error **errp); +void visit_end_struct(Visitor *v); /*** Visiting lists ***/ diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c index 4cb6436a1f..ece0598e34 100644 --- a/qapi/opts-visitor.c +++ b/qapi/opts-visitor.c @@ -159,13 +159,13 @@ opts_start_struct(Visitor *v, const char *name, void **obj, static void -opts_end_struct(Visitor *v, Error **errp) +opts_check_struct(Visitor *v, Error **errp) { OptsVisitor *ov = to_ov(v); GHashTableIter iter; GQueue *any; - if (--ov->depth > 0) { + if (ov->depth > 0) { return; } @@ -177,6 +177,18 @@ opts_end_struct(Visitor *v, Error **errp) first = g_queue_peek_head(any); error_setg(errp, QERR_INVALID_PARAMETER, first->name); } +} + + +static void +opts_end_struct(Visitor *v) +{ + OptsVisitor *ov = to_ov(v); + + if (--ov->depth > 0) { + return; + } + g_hash_table_destroy(ov->unprocessed_opts); ov->unprocessed_opts = NULL; if (ov->fake_id_opt) { @@ -516,6 +528,7 @@ opts_visitor_new(const QemuOpts *opts) ov->visitor.type = VISITOR_INPUT; ov->visitor.start_struct = &opts_start_struct; + ov->visitor.check_struct = &opts_check_struct; ov->visitor.end_struct = &opts_end_struct; ov->visitor.start_list = &opts_start_list; diff --git a/qapi/qapi-dealloc-visitor.c b/qapi/qapi-dealloc-visitor.c index 413d525ad8..9005badb25 100644 --- a/qapi/qapi-dealloc-visitor.c +++ b/qapi/qapi-dealloc-visitor.c @@ -67,7 +67,7 @@ static void qapi_dealloc_start_struct(Visitor *v, const char *name, void **obj, qapi_dealloc_push(qov, obj); } -static void qapi_dealloc_end_struct(Visitor *v, Error **errp) +static void qapi_dealloc_end_struct(Visitor *v) { QapiDeallocVisitor *qov = to_qov(v); void **obj = qapi_dealloc_pop(qov); diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c index fe6afe8ca8..58144f67b7 100644 --- a/qapi/qapi-visit-core.c +++ b/qapi/qapi-visit-core.c @@ -36,9 +36,16 @@ void visit_start_struct(Visitor *v, const char *name, void **obj, error_propagate(errp, err); } -void visit_end_struct(Visitor *v, Error **errp) +void visit_check_struct(Visitor *v, Error **errp) { - v->end_struct(v, errp); + if (v->check_struct) { + v->check_struct(v, errp); + } +} + +void visit_end_struct(Visitor *v) +{ + v->end_struct(v); } void visit_start_list(Visitor *v, const char *name, Error **errp) diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c index 30e7cb38f2..90b9df11c4 100644 --- a/qapi/qmp-input-visitor.c +++ b/qapi/qmp-input-visitor.c @@ -125,9 +125,11 @@ static void qmp_input_push(QmpInputVisitor *qiv, QObject *obj, Error **errp) } -static void qmp_input_pop(QmpInputVisitor *qiv, Error **errp) +static void qmp_input_check_struct(Visitor *v, Error **errp) { + QmpInputVisitor *qiv = to_qiv(v); StackObject *tos = &qiv->stack[qiv->nb_stack - 1]; + assert(qiv->nb_stack > 0); if (qiv->strict) { @@ -140,6 +142,20 @@ static void qmp_input_pop(QmpInputVisitor *qiv, Error **errp) if (g_hash_table_iter_next(&iter, (void **)&key, NULL)) { error_setg(errp, QERR_QMP_EXTRA_MEMBER, key); } + } + } +} + +static void qmp_input_pop(Visitor *v) +{ + QmpInputVisitor *qiv = to_qiv(v); + StackObject *tos = &qiv->stack[qiv->nb_stack - 1]; + + assert(qiv->nb_stack > 0); + + if (qiv->strict) { + GHashTable * const top_ht = qiv->stack[qiv->nb_stack - 1].h; + if (top_ht) { g_hash_table_unref(top_ht); } tos->h = NULL; @@ -175,12 +191,6 @@ static void qmp_input_start_struct(Visitor *v, const char *name, void **obj, } } -static void qmp_input_end_struct(Visitor *v, Error **errp) -{ - QmpInputVisitor *qiv = to_qiv(v); - - qmp_input_pop(qiv, errp); -} static void qmp_input_start_list(Visitor *v, const char *name, Error **errp) { @@ -218,12 +228,6 @@ static GenericList *qmp_input_next_list(Visitor *v, GenericList **list, return entry; } -static void qmp_input_end_list(Visitor *v) -{ - QmpInputVisitor *qiv = to_qiv(v); - - qmp_input_pop(qiv, &error_abort); -} static void qmp_input_start_alternate(Visitor *v, const char *name, GenericAlternate **obj, size_t size, @@ -383,10 +387,11 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj, bool strict) v->visitor.type = VISITOR_INPUT; v->visitor.start_struct = qmp_input_start_struct; - v->visitor.end_struct = qmp_input_end_struct; + v->visitor.check_struct = qmp_input_check_struct; + v->visitor.end_struct = qmp_input_pop; v->visitor.start_list = qmp_input_start_list; v->visitor.next_list = qmp_input_next_list; - v->visitor.end_list = qmp_input_end_list; + v->visitor.end_list = qmp_input_pop; v->visitor.start_alternate = qmp_input_start_alternate; v->visitor.type_int64 = qmp_input_type_int64; v->visitor.type_uint64 = qmp_input_type_uint64; diff --git a/qapi/qmp-output-visitor.c b/qapi/qmp-output-visitor.c index 4e21f1ddf0..232ad58221 100644 --- a/qapi/qmp-output-visitor.c +++ b/qapi/qmp-output-visitor.c @@ -111,7 +111,7 @@ static void qmp_output_start_struct(Visitor *v, const char *name, void **obj, qmp_output_push(qov, dict); } -static void qmp_output_end_struct(Visitor *v, Error **errp) +static void qmp_output_end_struct(Visitor *v) { QmpOutputVisitor *qov = to_qov(v); QObject *value = qmp_output_pop(qov); diff --git a/qom/object.c b/qom/object.c index 8e6e68dffc..3bc8a009bb 100644 --- a/qom/object.c +++ b/qom/object.c @@ -2036,10 +2036,9 @@ static void property_get_tm(Object *obj, Visitor *v, const char *name, if (err) { goto out_end; } + visit_check_struct(v, &err); out_end: - error_propagate(errp, err); - err = NULL; - visit_end_struct(v, errp); + visit_end_struct(v); out: error_propagate(errp, err); diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c index cad5542de6..51e62e29d6 100644 --- a/qom/object_interfaces.c +++ b/qom/object_interfaces.c @@ -42,7 +42,7 @@ Object *user_creatable_add(const QDict *qdict, char *type = NULL; char *id = NULL; Object *obj = NULL; - Error *local_err = NULL, *end_err = NULL; + Error *local_err = NULL; QDict *pdict; pdict = qdict_clone_shallow(qdict); @@ -63,21 +63,15 @@ Object *user_creatable_add(const QDict *qdict, if (local_err) { goto out_visit; } - - obj = user_creatable_add_type(type, id, pdict, v, &local_err); + visit_check_struct(v, &local_err); if (local_err) { goto out_visit; } - out_visit: - visit_end_struct(v, &end_err); - if (end_err) { - error_propagate(&local_err, end_err); - if (obj) { - user_creatable_del(id, NULL); - } - goto out; - } + obj = user_creatable_add_type(type, id, pdict, v, &local_err); + +out_visit: + visit_end_struct(v); out: QDECREF(pdict); @@ -130,7 +124,10 @@ Object *user_creatable_add_type(const char *type, const char *id, break; } } - visit_end_struct(v, local_err ? NULL : &local_err); + if (!local_err) { + visit_check_struct(v, &local_err); + } + visit_end_struct(v); if (local_err) { goto out; } diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py index 04549fa183..8c6acb3f3f 100644 --- a/scripts/qapi-commands.py +++ b/scripts/qapi-commands.py @@ -126,7 +126,10 @@ def gen_marshal(name, arg_type, ret_type): goto out; } visit_type_%(c_name)s_members(v, &arg, &err); - visit_end_struct(v, err ? NULL : &err); + if (!err) { + visit_check_struct(v, &err); + } + visit_end_struct(v); if (err) { goto out; } @@ -157,7 +160,7 @@ out: v = qapi_dealloc_get_visitor(qdv); visit_start_struct(v, NULL, NULL, 0, NULL); visit_type_%(c_name)s_members(v, &arg, NULL); - visit_end_struct(v, NULL); + visit_end_struct(v); qapi_dealloc_visitor_cleanup(qdv); ''', c_name=arg_type.c_name()) diff --git a/scripts/qapi-event.py b/scripts/qapi-event.py index 9b5c5b535d..21fb16744d 100644 --- a/scripts/qapi-event.py +++ b/scripts/qapi-event.py @@ -98,7 +98,10 @@ def gen_event_send(name, arg_type): goto out; } visit_type_%(c_name)s_members(v, ¶m, &err); - visit_end_struct(v, err ? NULL : &err); + if (!err) { + visit_check_struct(v, &err); + } + visit_end_struct(v); if (err) { goto out; } diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py index 31d2330356..bdf8971440 100644 --- a/scripts/qapi-visit.py +++ b/scripts/qapi-visit.py @@ -186,9 +186,10 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error break; } visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, &err); - error_propagate(errp, err); - err = NULL; - visit_end_struct(v, &err); + if (!err) { + visit_check_struct(v, &err); + } + visit_end_struct(v); ''', c_type=var.type.c_name(), c_name=c_name(var.name)) @@ -236,10 +237,12 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error goto out_obj; } visit_type_%(c_name)s_members(v, *obj, &err); - error_propagate(errp, err); - err = NULL; + if (err) { + goto out_obj; + } + visit_check_struct(v, &err); out_obj: - visit_end_struct(v, &err); + visit_end_struct(v); out: error_propagate(errp, err); } diff --git a/tests/test-qmp-input-visitor.c b/tests/test-qmp-input-visitor.c index 10e00ecbc7..6617276bce 100644 --- a/tests/test-qmp-input-visitor.c +++ b/tests/test-qmp-input-visitor.c @@ -303,7 +303,8 @@ static void test_visitor_in_null(TestInputVisitorData *data, error_free_or_abort(&err); visit_type_null(v, "b", &err); error_free_or_abort(&err); - visit_end_struct(v, &error_abort); + visit_check_struct(v, &error_abort); + visit_end_struct(v); } static void test_visitor_in_union_flat(TestInputVisitorData *data, diff --git a/tests/test-qmp-output-visitor.c b/tests/test-qmp-output-visitor.c index 5543511c21..1f80e696ea 100644 --- a/tests/test-qmp-output-visitor.c +++ b/tests/test-qmp-output-visitor.c @@ -498,7 +498,8 @@ static void test_visitor_out_null(TestOutputVisitorData *data, visit_start_struct(data->ov, NULL, NULL, 0, &error_abort); visit_type_null(data->ov, "a", &error_abort); - visit_end_struct(data->ov, &error_abort); + visit_check_struct(data->ov, &error_abort); + visit_end_struct(data->ov); arg = qmp_output_get_qobject(data->qov); g_assert(qobject_type(arg) == QTYPE_QDICT); qdict = qobject_to_qdict(arg); -- 2.11.0