On Mon, Sep 16, 2013 at 05:24:46PM +0200, Andreas Färber wrote: > Am 16.09.2013 14:33, schrieb Michael S. Tsirkin: > > On Mon, Sep 16, 2013 at 08:32:13AM +0200, Andreas Färber wrote: > >> Am 15.09.2013 19:23, schrieb Michael S. Tsirkin: > >>> Add a helper macro for adding read-only properties, that works in the > >>> common case where the value is a constant. > >>> > >>> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> > >>> --- > >>> > >>> I'm using this patch in my acpi work - any objections > >>> to applying it on my tree? > >> > >> Actually yes: Apart from the clang issues raised and the disturbing > >> upper-casing of arguments, this is hardcoding "int" type and NULL errp, > >> so I don't think it deserves to live in object.h as is. I do agree that > >> we could use more helper functions to deal with dynamic properties. > >> > >> So what about taking bool/string property helpers as example and putting > >> intX_t getters into object.c, using a passed-through opaque argument to > >> obtain the value? We could then have real object_property_add_int32() > >> etc. functions using the appropriate type name, with field/value pointer > >> and Error** arguments. A pointer can be assumed to hold up to uint32_t > >> values or, to keep the API more general, use a local static const > >> variable for non-field values. > > > > This reminds me. > > [mst@robin qemu]$ git grep object_property_set_bool > > backends/rng.c: object_property_set_bool(OBJECT(s), true, "opened", > > errp); > > backends/tpm.c: object_property_set_bool(OBJECT(s), true, "opened", > > errp); > > These look like two distinct properties used once each. > > [...] > > hw/core/qdev.c: object_property_set_bool(OBJECT(dev), true, "realized", > > &local_err); > [...] > > hw/core/qdev.c: object_property_set_bool(obj, false, "realized", > > NULL); > > hw/i386/pc.c: object_property_set_bool(OBJECT(cpu), true, "realized", > > &local_err); > > hw/pci-host/prep.c: object_property_set_bool(OBJECT(&s->pci_dev), true, > > "realized", errp); > > hw/pci-host/versatile.c: object_property_set_bool(OBJECT(&s->pci_dev), > > true, "realized", errp) > > hw/scsi/scsi-bus.c: object_property_set_bool(OBJECT(dev), true, > > "realized", &err); > [...] > > target-alpha/cpu.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-arm/helper.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-cris/cpu.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-i386/cpu.c: object_property_set_bool(OBJECT(cpu), true, > > "pmu", &err); > > target-i386/cpu.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", &error); > > target-lm32/helper.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-m68k/helper.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-microblaze/translate.c: object_property_set_bool(OBJECT(cpu), > > true, "realized", NULL); > > target-mips/translate.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-moxie/cpu.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-openrisc/cpu.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-ppc/translate_init.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", &err); > > target-s390x/helper.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-sh4/cpu.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-sparc/cpu.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-unicore32/helper.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > target-xtensa/helper.c: object_property_set_bool(OBJECT(cpu), true, > > "realized", NULL); > > Leaving the bulk for "realized". > > > > > Shouldn't we have a constant for the "realized" string? > > That's a two-sided sword: We actually shouldn't be setting realized = > true manually but once on machine init - in that case we wouldn't > strictly need a constant. > > I pushed to get that central infrastructure in place to spare me/us the > repetitive realized = true setting, but Paolo shot it down, asking for a > full-fledged solver to make ordering guarantees. > > > If there's a typo somewhere it will all fail at runtime > > in a hard to debug way, won't it? > > It would. However, this is typically executed once on startup, so with > proper error handling we should notice this immediately. My qom-test > (that Anthony didn't take for 1.6 and I still need to respin) served to > test them, with focus on SysBusDevices. > > You are cordially invited to add trivial qtests covering instantiation > of PCI/virtio devices you care about. :) > > Andreas
http://sweng.the-davies.net/Home/rustys-api-design-manifesto Even then: it will be at best "5. Do it right or it will always break at runtime." We need to switch to APIs at "9. The compiler/linker won't let you get it wrong." > -- > SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany > GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
