| Message ID | 1460131992-32278-15-git-send-email-eblake@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Eric Blake <eblake@redhat.com> writes: > 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 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: > > Signed-off-by: Eric Blake <eblake@redhat.com> > > --- > v14: rebase to master > v13: rebase to earlier changes > v12: rebase to earlier changes, fix bug in spapr_drc not calling > visit_end_struct, fold in docs, fix stray DO_UPCAST from sneaking > back in > [no v10, v11] > v9: rebase to earlier changes, drop Marc-Andre's R-b > v8: rebase to 'name' motion > v7: rebase to earlier changes > v6: new patch, revised version of RFC based on discussion of v5 7/46 > --- > include/qapi/visitor.h | 20 +++++++++++++++----- > include/qapi/visitor-impl.h | 5 ++++- > scripts/qapi-event.py | 5 ++++- > scripts/qapi-visit.py | 15 +++++++++------ > qapi/qapi-visit-core.c | 11 +++++++++-- > block/crypto.c | 14 ++++++++------ > hw/ppc/spapr_drc.c | 3 ++- > hw/virtio/virtio-balloon.c | 15 ++++++++------- > qapi/opts-visitor.c | 17 +++++++++++++++-- > qapi/qapi-dealloc-visitor.c | 2 +- > qapi/qmp-input-visitor.c | 34 +++++++++++++++++++--------------- > qapi/qmp-output-visitor.c | 2 +- > qom/object.c | 5 ++--- > qom/object_interfaces.c | 16 +++++++--------- > tests/test-qmp-input-visitor.c | 3 ++- > docs/qapi-code-gen.txt | 8 +++++--- > 16 files changed, 111 insertions(+), 64 deletions(-) > > diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h > index 735b389..4c29722 100644 > --- a/include/qapi/visitor.h > +++ b/include/qapi/visitor.h > @@ -182,10 +182,11 @@ > * } > * 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); > * error_propagate(errp, err); > * ...clean up v... > * </example> > @@ -238,17 +239,26 @@ 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 must be NULL-initialized, and is set if an error is detected > * (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. > + */ > +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 may > * behave 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/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h > index 90bcaec..d44fcd1 100644 > --- a/include/qapi/visitor-impl.h > +++ b/include/qapi/visitor-impl.h > @@ -39,8 +39,11 @@ 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/scripts/qapi-event.py b/scripts/qapi-event.py > index 9b5c5b5..21fb167 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 dc8b39c..bfe4a09 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/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c > index 064b9f1..76ea690 100644 > --- a/qapi/qapi-visit-core.c > +++ b/qapi/qapi-visit-core.c > @@ -30,9 +30,16 @@ void visit_start_struct(Visitor *v, const char *name, void **obj, > v->start_struct(v, name, obj, size, errp); > } > > -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/block/crypto.c b/block/crypto.c > index 1903e84..2424a4c 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/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c > index 72d725c..5395c02 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 c74101e..47f5f5e 100644 > --- a/hw/virtio/virtio-balloon.c > +++ b/hw/virtio/virtio-balloon.c > @@ -137,17 +137,18 @@ 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/qapi/opts-visitor.c b/qapi/opts-visitor.c > index cdb6e42..a08d5a7 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) { > @@ -511,6 +523,7 @@ 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 413d525..9005bad 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/qmp-input-visitor.c b/qapi/qmp-input-visitor.c > index e5b412a..a94cfa9 100644 > --- a/qapi/qmp-input-visitor.c > +++ b/qapi/qmp-input-visitor.c > @@ -124,8 +124,10 @@ static void qmp_input_push(QmpInputVisitor *qiv, QObject *obj, > } > > > -static void qmp_input_pop(QmpInputVisitor *qiv, Error **errp) > +static void qmp_input_check_struct(Visitor *v, Error **errp) > { > + QmpInputVisitor *qiv = to_qiv(v); > + > assert(qiv->nb_stack > 0); > > if (qiv->strict) { > @@ -138,6 +140,19 @@ 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); > + > + 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); > } > } > @@ -172,12 +187,6 @@ 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) > { > @@ -217,12 +226,6 @@ 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, > @@ -382,10 +385,11 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj) > > 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 7c48dfb..ecb2005 100644 > --- a/qapi/qmp-output-visitor.c > +++ b/qapi/qmp-output-visitor.c > @@ -113,7 +113,7 @@ 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 8e6e68d..3bc8a00 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 ab5da35..a0bf6b7 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); > @@ -69,16 +69,14 @@ Object *user_creatable_add(const QDict *qdict, > 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; > + visit_check_struct(v, &local_err); > + if (local_err) { > + user_creatable_del(id, NULL); > } > > +out_visit: > + visit_end_struct(v); > + > out: > QDECREF(pdict); > g_free(id); I think this could be simplified further: visit_check_struct(v, &local_err); if (local_err) { goto out_visit; } obj = user_creatable_add_type(type, id, pdict, v, &local_err); out_visit: visit_end_struct(v); out: > diff --git a/tests/test-qmp-input-visitor.c b/tests/test-qmp-input-visitor.c > index d06383a..ac8ebea 100644 > --- a/tests/test-qmp-input-visitor.c > +++ b/tests/test-qmp-input-visitor.c > @@ -290,7 +290,8 @@ static void test_visitor_in_null(TestInputVisitorData *data, > v = visitor_input_test_init(data, "{ 'a': null }"); > visit_start_struct(v, NULL, NULL, 0, &error_abort); > visit_type_null(v, "a", &error_abort); > - 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/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt > index 0e4baff..3b2422f 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); > }
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h index 735b389..4c29722 100644 --- a/include/qapi/visitor.h +++ b/include/qapi/visitor.h @@ -182,10 +182,11 @@ * } * 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); * error_propagate(errp, err); * ...clean up v... * </example> @@ -238,17 +239,26 @@ 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 must be NULL-initialized, and is set if an error is detected * (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. + */ +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 may * behave 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/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h index 90bcaec..d44fcd1 100644 --- a/include/qapi/visitor-impl.h +++ b/include/qapi/visitor-impl.h @@ -39,8 +39,11 @@ 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/scripts/qapi-event.py b/scripts/qapi-event.py index 9b5c5b5..21fb167 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 dc8b39c..bfe4a09 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/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c index 064b9f1..76ea690 100644 --- a/qapi/qapi-visit-core.c +++ b/qapi/qapi-visit-core.c @@ -30,9 +30,16 @@ void visit_start_struct(Visitor *v, const char *name, void **obj, v->start_struct(v, name, obj, size, errp); } -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/block/crypto.c b/block/crypto.c index 1903e84..2424a4c 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/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c index 72d725c..5395c02 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 c74101e..47f5f5e 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -137,17 +137,18 @@ 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/qapi/opts-visitor.c b/qapi/opts-visitor.c index cdb6e42..a08d5a7 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) { @@ -511,6 +523,7 @@ 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 413d525..9005bad 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/qmp-input-visitor.c b/qapi/qmp-input-visitor.c index e5b412a..a94cfa9 100644 --- a/qapi/qmp-input-visitor.c +++ b/qapi/qmp-input-visitor.c @@ -124,8 +124,10 @@ static void qmp_input_push(QmpInputVisitor *qiv, QObject *obj, } -static void qmp_input_pop(QmpInputVisitor *qiv, Error **errp) +static void qmp_input_check_struct(Visitor *v, Error **errp) { + QmpInputVisitor *qiv = to_qiv(v); + assert(qiv->nb_stack > 0); if (qiv->strict) { @@ -138,6 +140,19 @@ 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); + + 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); } } @@ -172,12 +187,6 @@ 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) { @@ -217,12 +226,6 @@ 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, @@ -382,10 +385,11 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj) 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 7c48dfb..ecb2005 100644 --- a/qapi/qmp-output-visitor.c +++ b/qapi/qmp-output-visitor.c @@ -113,7 +113,7 @@ 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 8e6e68d..3bc8a00 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 ab5da35..a0bf6b7 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); @@ -69,16 +69,14 @@ Object *user_creatable_add(const QDict *qdict, 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; + visit_check_struct(v, &local_err); + if (local_err) { + user_creatable_del(id, NULL); } +out_visit: + visit_end_struct(v); + out: QDECREF(pdict); g_free(id); diff --git a/tests/test-qmp-input-visitor.c b/tests/test-qmp-input-visitor.c index d06383a..ac8ebea 100644 --- a/tests/test-qmp-input-visitor.c +++ b/tests/test-qmp-input-visitor.c @@ -290,7 +290,8 @@ static void test_visitor_in_null(TestInputVisitorData *data, v = visitor_input_test_init(data, "{ 'a': null }"); visit_start_struct(v, NULL, NULL, 0, &error_abort); visit_type_null(v, "a", &error_abort); - 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/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt index 0e4baff..3b2422f 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); }
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 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: Signed-off-by: Eric Blake <eblake@redhat.com> --- v14: rebase to master v13: rebase to earlier changes v12: rebase to earlier changes, fix bug in spapr_drc not calling visit_end_struct, fold in docs, fix stray DO_UPCAST from sneaking back in [no v10, v11] v9: rebase to earlier changes, drop Marc-Andre's R-b v8: rebase to 'name' motion v7: rebase to earlier changes v6: new patch, revised version of RFC based on discussion of v5 7/46 --- include/qapi/visitor.h | 20 +++++++++++++++----- include/qapi/visitor-impl.h | 5 ++++- scripts/qapi-event.py | 5 ++++- scripts/qapi-visit.py | 15 +++++++++------ qapi/qapi-visit-core.c | 11 +++++++++-- block/crypto.c | 14 ++++++++------ hw/ppc/spapr_drc.c | 3 ++- hw/virtio/virtio-balloon.c | 15 ++++++++------- qapi/opts-visitor.c | 17 +++++++++++++++-- qapi/qapi-dealloc-visitor.c | 2 +- qapi/qmp-input-visitor.c | 34 +++++++++++++++++++--------------- qapi/qmp-output-visitor.c | 2 +- qom/object.c | 5 ++--- qom/object_interfaces.c | 16 +++++++--------- tests/test-qmp-input-visitor.c | 3 ++- docs/qapi-code-gen.txt | 8 +++++--- 16 files changed, 111 insertions(+), 64 deletions(-)