From 2c0ef9f411ae6081efa9eca5b3eab2dbeee45a6c Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Thu, 9 Jun 2016 10:48:35 -0600 Subject: [PATCH] qapi: Add new visit_free() function Making each visitor provide its own (awkwardly-named) FOO_cleanup() is unusual, when we can instead have a polymorphic visit_free() interface. Over the next few patches, we can use the polymorphic functions to eliminate the need for a FOO_get_visitor() function for accessing specific visitor functionality, once everything can be accessed directly through the Visitor* interfaces. The dealloc visitor is the first one converted to completely use the new entry point, since qapi_dealloc_visitor_cleanup() was the only reason that qapi_dealloc_get_visitor() existed, and only generated and testsuite code was even using it. With the new visit_free() entry point in place, we no longer need to expose the QapiDeallocVisitor subtype through qapi_dealloc_visitor_new(), and can get by with less generated code, with diffs that look like: | void qapi_free_ACPIOSTInfo(ACPIOSTInfo *obj) | { |- QapiDeallocVisitor *qdv; | Visitor *v; | | if (!obj) { | return; | } | |- qdv = qapi_dealloc_visitor_new(); |- v = qapi_dealloc_get_visitor(qdv); |+ v = qapi_dealloc_visitor_new(); | visit_type_ACPIOSTInfo(v, NULL, &obj, NULL); |- qapi_dealloc_visitor_cleanup(qdv); |+ visit_free(v); |} Signed-off-by: Eric Blake Message-Id: <1465490926-28625-5-git-send-email-eblake@redhat.com> Reviewed-by: Markus Armbruster Signed-off-by: Markus Armbruster --- docs/qapi-code-gen.txt | 28 ++++++++++------------------ include/qapi/dealloc-visitor.h | 5 +---- include/qapi/visitor-impl.h | 3 +++ include/qapi/visitor.h | 37 ++++++++++++++++++++++++++++++++++--- qapi/opts-visitor.c | 10 ++++++++++ qapi/qapi-dealloc-visitor.c | 14 +++++--------- qapi/qapi-visit-core.c | 7 +++++++ qapi/qmp-input-visitor.c | 8 ++++++++ qapi/qmp-output-visitor.c | 8 ++++++++ qapi/string-input-visitor.c | 8 ++++++++ qapi/string-output-visitor.c | 8 ++++++++ scripts/qapi-commands.py | 16 ++++++---------- scripts/qapi-event.py | 2 +- scripts/qapi-types.py | 6 ++---- tests/test-visitor-serialization.c | 6 +++--- 15 files changed, 114 insertions(+), 52 deletions(-) diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt index 0ae239ad6c..db9d5b6357 100644 --- a/docs/qapi-code-gen.txt +++ b/docs/qapi-code-gen.txt @@ -802,32 +802,28 @@ Example: void qapi_free_UserDefOne(UserDefOne *obj) { - QapiDeallocVisitor *qdv; Visitor *v; if (!obj) { return; } - qdv = qapi_dealloc_visitor_new(); - v = qapi_dealloc_get_visitor(qdv); + v = qapi_dealloc_visitor_new(); visit_type_UserDefOne(v, NULL, &obj, NULL); - qapi_dealloc_visitor_cleanup(qdv); + visit_free(v); } void qapi_free_UserDefOneList(UserDefOneList *obj) { - QapiDeallocVisitor *qdv; Visitor *v; if (!obj) { return; } - qdv = qapi_dealloc_visitor_new(); - v = qapi_dealloc_get_visitor(qdv); + v = qapi_dealloc_visitor_new(); visit_type_UserDefOneList(v, NULL, &obj, NULL); - qapi_dealloc_visitor_cleanup(qdv); + visit_free(v); } === scripts/qapi-visit.py === @@ -985,7 +981,6 @@ Example: { Error *err = NULL; QmpOutputVisitor *qov = qmp_output_visitor_new(); - QapiDeallocVisitor *qdv; Visitor *v; v = qmp_output_get_visitor(qov); @@ -997,11 +992,10 @@ Example: out: error_propagate(errp, err); - qmp_output_visitor_cleanup(qov); - qdv = qapi_dealloc_visitor_new(); - v = qapi_dealloc_get_visitor(qdv); + visit_free(v); + v = qapi_dealloc_visitor_new(); visit_type_UserDefOne(v, "unused", &ret_in, NULL); - qapi_dealloc_visitor_cleanup(qdv); + visit_free(v); } static void qmp_marshal_my_command(QDict *args, QObject **ret, Error **errp) @@ -1009,7 +1003,6 @@ Example: Error *err = NULL; UserDefOne *retval; QmpInputVisitor *qiv = qmp_input_visitor_new(QOBJECT(args), true); - QapiDeallocVisitor *qdv; Visitor *v; UserDefOneList *arg1 = NULL; @@ -1036,13 +1029,12 @@ Example: out: error_propagate(errp, err); - qmp_input_visitor_cleanup(qiv); - qdv = qapi_dealloc_visitor_new(); - v = qapi_dealloc_get_visitor(qdv); + visit_free(v); + v = qapi_dealloc_visitor_new(); visit_start_struct(v, NULL, NULL, 0, NULL); visit_type_UserDefOneList(v, "arg1", &arg1, NULL); visit_end_struct(v, NULL); - qapi_dealloc_visitor_cleanup(qdv); + visit_free(v); } static void qmp_init_marshal(void) diff --git a/include/qapi/dealloc-visitor.h b/include/qapi/dealloc-visitor.h index 45b06b248c..b3e5c85fd8 100644 --- a/include/qapi/dealloc-visitor.h +++ b/include/qapi/dealloc-visitor.h @@ -23,9 +23,6 @@ typedef struct QapiDeallocVisitor QapiDeallocVisitor; * qapi_free_FOO() functions, and is the only visitor designed to work * correctly in the face of a partially-constructed QAPI tree. */ -QapiDeallocVisitor *qapi_dealloc_visitor_new(void); -void qapi_dealloc_visitor_cleanup(QapiDeallocVisitor *d); - -Visitor *qapi_dealloc_get_visitor(QapiDeallocVisitor *v); +Visitor *qapi_dealloc_visitor_new(void); #endif diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h index a495bf0937..525b06872b 100644 --- a/include/qapi/visitor-impl.h +++ b/include/qapi/visitor-impl.h @@ -104,6 +104,9 @@ struct Visitor /* Must be set */ VisitorType type; + + /* Must be set */ + void (*free)(Visitor *v); }; #endif diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h index 25d0cc275a..2ded852307 100644 --- a/include/qapi/visitor.h +++ b/include/qapi/visitor.h @@ -37,6 +37,24 @@ * implemented by each visitor, and docs/qapi-code-gen.txt for more * about the QAPI code generator. * + * All of the visitors are created via: + * + * Type *subtype_visitor_new(parameters...); + * + * where Type is either directly 'Visitor *', or is a subtype that can + * be trivially upcast to Visitor * via another function: + * + * Visitor *subtype_get_visitor(SubtypeVisitor *); + * + * A visitor should be used for exactly one top-level visit_type_FOO() + * or virtual walk, then passed to visit_free() to clean up resources. + * It is okay to free the visitor without completing the visit, if + * some other error is detected in the meantime. Output visitors + * provide an additional function, for collecting the final results of + * a successful visit: string_output_get_string() and + * qmp_output_get_qobject(); this collection function should not be + * called if any errors were reported during the visit. + * * All QAPI types have a corresponding function with a signature * roughly compatible with this: * @@ -222,6 +240,19 @@ typedef struct GenericAlternate { char padding[]; } GenericAlternate; +/*** Visitor cleanup ***/ + +/* + * Free @v and any resources it has tied up. + * + * May be called whether or not the visit has been successfully + * completed, but should not be called until a top-level + * visit_type_FOO() or visit_start_ITEM() has been performed on the + * visitor. Safe if @v is NULL. + */ +void visit_free(Visitor *v); + + /*** Visiting structures ***/ /* @@ -272,7 +303,7 @@ void visit_check_struct(Visitor *v, Error **errp); * 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. + * with visit_free() behaves as if this was implicitly called. */ void visit_end_struct(Visitor *v, void **obj); @@ -332,7 +363,7 @@ GenericList *visit_next_list(Visitor *v, GenericList *tail, size_t size); * Must be called after any successful use of visit_start_list(), 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. + * with visit_free() behaves as if this was implicitly called. */ void visit_end_list(Visitor *v, void **list); @@ -368,7 +399,7 @@ void visit_start_alternate(Visitor *v, const char *name, * Must be called after any successful use of visit_start_alternate(), * 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. + * with visit_free() behaves as if this was implicitly called. * */ void visit_end_alternate(Visitor *v, void **obj); diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c index dcfbf92faf..72c95ac7c1 100644 --- a/qapi/opts-visitor.c +++ b/qapi/opts-visitor.c @@ -513,6 +513,15 @@ opts_optional(Visitor *v, const char *name, bool *present) } +static void +opts_free(Visitor *v) +{ + OptsVisitor *ov = to_ov(v); + + opts_visitor_cleanup(ov); +} + + OptsVisitor * opts_visitor_new(const QemuOpts *opts) { @@ -540,6 +549,7 @@ opts_visitor_new(const QemuOpts *opts) * skip some mandatory methods... */ ov->visitor.optional = &opts_optional; + ov->visitor.free = opts_free; ov->opts_root = opts; diff --git a/qapi/qapi-dealloc-visitor.c b/qapi/qapi-dealloc-visitor.c index 9391dea203..e39457bc79 100644 --- a/qapi/qapi-dealloc-visitor.c +++ b/qapi/qapi-dealloc-visitor.c @@ -107,17 +107,12 @@ static void qapi_dealloc_type_null(Visitor *v, const char *name, Error **errp) { } -Visitor *qapi_dealloc_get_visitor(QapiDeallocVisitor *v) +static void qapi_dealloc_free(Visitor *v) { - return &v->visitor; + g_free(container_of(v, QapiDeallocVisitor, visitor)); } -void qapi_dealloc_visitor_cleanup(QapiDeallocVisitor *v) -{ - g_free(v); -} - -QapiDeallocVisitor *qapi_dealloc_visitor_new(void) +Visitor *qapi_dealloc_visitor_new(void) { QapiDeallocVisitor *v; @@ -138,6 +133,7 @@ QapiDeallocVisitor *qapi_dealloc_visitor_new(void) v->visitor.type_number = qapi_dealloc_type_number; v->visitor.type_any = qapi_dealloc_type_anything; v->visitor.type_null = qapi_dealloc_type_null; + v->visitor.free = qapi_dealloc_free; - return v; + return &v->visitor; } diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c index dba11c66a7..5f68c251d2 100644 --- a/qapi/qapi-visit-core.c +++ b/qapi/qapi-visit-core.c @@ -20,6 +20,13 @@ #include "qapi/visitor.h" #include "qapi/visitor-impl.h" +void visit_free(Visitor *v) +{ + if (v) { + v->free(v); + } +} + void visit_start_struct(Visitor *v, const char *name, void **obj, size_t size, Error **errp) { diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c index e16b4b0725..41b7f87ddb 100644 --- a/qapi/qmp-input-visitor.c +++ b/qapi/qmp-input-visitor.c @@ -378,6 +378,13 @@ Visitor *qmp_input_get_visitor(QmpInputVisitor *v) return &v->visitor; } +static void qmp_input_free(Visitor *v) +{ + QmpInputVisitor *qiv = to_qiv(v); + + qmp_input_visitor_cleanup(qiv); +} + void qmp_input_visitor_cleanup(QmpInputVisitor *v) { qobject_decref(v->root); @@ -406,6 +413,7 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj, bool strict) v->visitor.type_any = qmp_input_type_any; v->visitor.type_null = qmp_input_type_null; v->visitor.optional = qmp_input_optional; + v->visitor.free = qmp_input_free; v->strict = strict; v->root = obj; diff --git a/qapi/qmp-output-visitor.c b/qapi/qmp-output-visitor.c index dca893584d..5f0035cbf6 100644 --- a/qapi/qmp-output-visitor.c +++ b/qapi/qmp-output-visitor.c @@ -214,6 +214,13 @@ Visitor *qmp_output_get_visitor(QmpOutputVisitor *v) return &v->visitor; } +static void qmp_output_free(Visitor *v) +{ + QmpOutputVisitor *qov = to_qov(v); + + qmp_output_visitor_cleanup(qov); +} + void qmp_output_visitor_cleanup(QmpOutputVisitor *v) { QStackEntry *e, *tmp; @@ -246,6 +253,7 @@ QmpOutputVisitor *qmp_output_visitor_new(void) v->visitor.type_number = qmp_output_type_number; v->visitor.type_any = qmp_output_type_any; v->visitor.type_null = qmp_output_type_null; + v->visitor.free = qmp_output_free; QTAILQ_INIT(&v->stack); diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c index d7f3c2bd1e..6fb1229586 100644 --- a/qapi/string-input-visitor.c +++ b/qapi/string-input-visitor.c @@ -331,6 +331,13 @@ Visitor *string_input_get_visitor(StringInputVisitor *v) return &v->visitor; } +static void string_input_free(Visitor *v) +{ + StringInputVisitor *siv = to_siv(v); + + string_input_visitor_cleanup(siv); +} + void string_input_visitor_cleanup(StringInputVisitor *v) { g_list_foreach(v->ranges, free_range, NULL); @@ -355,6 +362,7 @@ StringInputVisitor *string_input_visitor_new(const char *str) v->visitor.next_list = next_list; v->visitor.end_list = end_list; v->visitor.optional = parse_optional; + v->visitor.free = string_input_free; v->string = str; return v; diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c index bdc0fd0be4..ff9ddf068a 100644 --- a/qapi/string-output-visitor.c +++ b/qapi/string-output-visitor.c @@ -322,6 +322,13 @@ static void free_range(void *range, void *dummy) g_free(range); } +static void string_output_free(Visitor *v) +{ + StringOutputVisitor *sov = to_sov(v); + + string_output_visitor_cleanup(sov); +} + void string_output_visitor_cleanup(StringOutputVisitor *sov) { if (sov->string) { @@ -351,6 +358,7 @@ StringOutputVisitor *string_output_visitor_new(bool human) v->visitor.start_list = start_list; v->visitor.next_list = next_list; v->visitor.end_list = end_list; + v->visitor.free = string_output_free; return v; } diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py index 971dc4ea8e..77ecd47071 100644 --- a/scripts/qapi-commands.py +++ b/scripts/qapi-commands.py @@ -62,7 +62,6 @@ static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out, { Error *err = NULL; QmpOutputVisitor *qov = qmp_output_visitor_new(); - QapiDeallocVisitor *qdv; Visitor *v; v = qmp_output_get_visitor(qov); @@ -74,11 +73,10 @@ static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out, out: error_propagate(errp, err); - qmp_output_visitor_cleanup(qov); - qdv = qapi_dealloc_visitor_new(); - v = qapi_dealloc_get_visitor(qdv); + visit_free(v); + v = qapi_dealloc_visitor_new(); visit_type_%(c_name)s(v, "unused", &ret_in, NULL); - qapi_dealloc_visitor_cleanup(qdv); + visit_free(v); } ''', c_type=ret_type.c_type(), c_name=ret_type.c_name()) @@ -116,7 +114,6 @@ def gen_marshal(name, arg_type, ret_type): if arg_type and arg_type.members: ret += mcgen(''' QmpInputVisitor *qiv = qmp_input_visitor_new(QOBJECT(args), true); - QapiDeallocVisitor *qdv; Visitor *v; %(c_name)s arg = {0}; @@ -155,13 +152,12 @@ out: ''') if arg_type and arg_type.members: ret += mcgen(''' - qmp_input_visitor_cleanup(qiv); - qdv = qapi_dealloc_visitor_new(); - v = qapi_dealloc_get_visitor(qdv); + visit_free(v); + v = qapi_dealloc_visitor_new(); visit_start_struct(v, NULL, NULL, 0, NULL); visit_type_%(c_name)s_members(v, &arg, NULL); visit_end_struct(v, NULL); - qapi_dealloc_visitor_cleanup(qdv); + visit_free(v); ''', c_name=arg_type.c_name()) diff --git a/scripts/qapi-event.py b/scripts/qapi-event.py index 084c40a100..909e8d6b8f 100644 --- a/scripts/qapi-event.py +++ b/scripts/qapi-event.py @@ -119,7 +119,7 @@ def gen_event_send(name, arg_type): if arg_type and arg_type.members: ret += mcgen(''' out: - qmp_output_visitor_cleanup(qov); + visit_free(v); ''') ret += mcgen(''' error_propagate(errp, err); diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py index 437cf6c8e3..5ace2cf065 100644 --- a/scripts/qapi-types.py +++ b/scripts/qapi-types.py @@ -150,17 +150,15 @@ def gen_type_cleanup(name): void qapi_free_%(c_name)s(%(c_name)s *obj) { - QapiDeallocVisitor *qdv; Visitor *v; if (!obj) { return; } - qdv = qapi_dealloc_visitor_new(); - v = qapi_dealloc_get_visitor(qdv); + v = qapi_dealloc_visitor_new(); visit_type_%(c_name)s(v, NULL, &obj, NULL); - qapi_dealloc_visitor_cleanup(qdv); + visit_free(v); } ''', c_name=c_name(name)) diff --git a/tests/test-visitor-serialization.c b/tests/test-visitor-serialization.c index db781c0a79..bcbfd2aeb7 100644 --- a/tests/test-visitor-serialization.c +++ b/tests/test-visitor-serialization.c @@ -89,11 +89,11 @@ typedef void (*VisitorFunc)(Visitor *v, void **native, Error **errp); static void dealloc_helper(void *native_in, VisitorFunc visit, Error **errp) { - QapiDeallocVisitor *qdv = qapi_dealloc_visitor_new(); + Visitor *v = qapi_dealloc_visitor_new(); - visit(qapi_dealloc_get_visitor(qdv), &native_in, errp); + visit(v, &native_in, errp); - qapi_dealloc_visitor_cleanup(qdv); + visit_free(v); } static void visit_primitive_type(Visitor *v, void **native, Error **errp) -- 2.11.0