From a95291007b2478fcf32a2d71bf133b688bb4b675 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Tue, 18 Dec 2018 19:22:21 +0100 Subject: qapi: Eliminate indirection through qmp_event_get_func_emit() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The qapi_event_send_FOO() functions emit events like this: QMPEventFuncEmit emit; emit = qmp_event_get_func_emit(); if (!emit) { return; } qmp = qmp_event_build_dict("FOO"); [put event arguments into @qmp...] emit(QAPI_EVENT_FOO, qmp); The value of qmp_event_get_func_emit() depends only on the program: * In qemu-system-FOO, it's always monitor_qapi_event_queue. * In tests/test-qmp-event, it's always event_test_emit. * In all other programs, it's always null. This is exactly the kind of dependence the linker is supposed to resolve; we don't actually need an indirection. Note that things would fall apart if we linked more than one QAPI schema into a single program: each set of qapi_event_send_FOO() uses its own event enumeration, yet they share a single emit function. Which takes the event enumeration as an argument. Which one if there's more than one? More seriously: how does this work even now? qemu-system-FOO wants QAPIEvent, and passes a function taking that to qmp_event_set_func_emit(). test-qmp-event wants test_QAPIEvent, and passes a function taking that to qmp_event_set_func_emit(). It works by type trickery, of course: typedef void (*QMPEventFuncEmit)(unsigned event, QDict *dict); void qmp_event_set_func_emit(QMPEventFuncEmit emit); QMPEventFuncEmit qmp_event_get_func_emit(void); We use unsigned instead of the enumeration type. Relies on both enumerations boiling down to unsigned, which happens to be true for the compilers we use. Clean this up as follows: * Generate qapi_event_send_FOO() that call PREFIX_qapi_event_emit() instead of the value of qmp_event_set_func_emit(). * Generate a prototype for PREFIX_qapi_event_emit() into qapi-events.h. * PREFIX_ is empty for qapi/qapi-schema.json, and test_ for tests/qapi-schema/qapi-schema-test.json. It's qga_ for qga/qapi-schema.json, and doc-good- for tests/qapi-schema/doc-good.json, but those don't define any events. * Rename monitor_qapi_event_queue() to qapi_event_emit() instead of passing it to qmp_event_set_func_emit(). This takes care of qemu-system-FOO. * Rename event_test_emit() to test_qapi_event_emit() instead of passing it to qmp_event_set_func_emit(). This takes care of tests/test-qmp-event. * Add a qapi_event_emit() that does nothing to stubs/monitor.c. This takes care of all other programs that link code emitting QMP events. * Drop qmp_event_set_func_emit(), qmp_event_get_func_emit(). Signed-off-by: Markus Armbruster Message-Id: <20181218182234.28876-3-armbru@redhat.com> Reviewed-by: Marc-André Lureau [Commit message typos fixed] --- tests/test-qmp-event.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'tests/test-qmp-event.c') diff --git a/tests/test-qmp-event.c b/tests/test-qmp-event.c index 9cddd72adb..bf900f14f4 100644 --- a/tests/test-qmp-event.c +++ b/tests/test-qmp-event.c @@ -93,9 +93,7 @@ static bool qdict_cmp_simple(QDict *a, QDict *b) return d.result; } -/* This function is hooked as final emit function, which can verify the - correctness. */ -static void event_test_emit(test_QAPIEvent event, QDict *d) +void test_qapi_event_emit(test_QAPIEvent event, QDict *d) { QDict *t; int64_t s, ms; @@ -241,8 +239,6 @@ static void test_event_d(TestEventData *data, int main(int argc, char **argv) { - qmp_event_set_func_emit(event_test_emit); - g_test_init(&argc, &argv, NULL); event_test_add("/event/event_a", test_event_a); -- cgit v1.2.3