From d2623129a7dec1d3041ad1221dda1ca49c667532 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Tue, 5 May 2020 17:29:22 +0200 Subject: qom: Drop parameter @errp of object_property_add() & friends The only way object_property_add() can fail is when a property with the same name already exists. Since our property names are all hardcoded, failure is a programming error, and the appropriate way to handle it is passing &error_abort. Same for its variants, except for object_property_add_child(), which additionally fails when the child already has a parent. Parentage is also under program control, so this is a programming error, too. We have a bit over 500 callers. Almost half of them pass &error_abort, slightly fewer ignore errors, one test case handles errors, and the remaining few callers pass them to their own callers. The previous few commits demonstrated once again that ignoring programming errors is a bad idea. Of the few ones that pass on errors, several violate the Error API. The Error ** argument must be NULL, &error_abort, &error_fatal, or a pointer to a variable containing NULL. Passing an argument of the latter kind twice without clearing it in between is wrong: if the first call sets an error, it no longer points to NULL for the second call. ich9_pm_add_properties(), sparc32_ledma_realize(), sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize() are wrong that way. When the one appropriate choice of argument is &error_abort, letting users pick the argument is a bad idea. Drop parameter @errp and assert the preconditions instead. There's one exception to "duplicate property name is a programming error": the way object_property_add() implements the magic (and undocumented) "automatic arrayification". Don't drop @errp there. Instead, rename object_property_add() to object_property_try_add(), and add the obvious wrapper object_property_add(). Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Reviewed-by: Paolo Bonzini Message-Id: <20200505152926.18877-15-armbru@redhat.com> [Two semantic rebase conflicts resolved] --- hw/cpu/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'hw/cpu') diff --git a/hw/cpu/core.c b/hw/cpu/core.c index 9874c5c870..a92ac597ca 100644 --- a/hw/cpu/core.c +++ b/hw/cpu/core.c @@ -76,9 +76,9 @@ static void cpu_core_instance_init(Object *obj) CPUCore *core = CPU_CORE(obj); object_property_add(obj, "core-id", "int", core_prop_get_core_id, - core_prop_set_core_id, NULL, NULL, NULL); + core_prop_set_core_id, NULL, NULL); object_property_add(obj, "nr-threads", "int", core_prop_get_nr_threads, - core_prop_set_nr_threads, NULL, NULL, NULL); + core_prop_set_nr_threads, NULL, NULL); core->nr_threads = ms->smp.threads; } -- cgit v1.2.3