qdev: Replace no_user by cannot_instantiate_with_device_add_yet

In an ideal world, machines can be built by wiring devices together
with configuration, not code.  Unfortunately, that's not the world we
live in right now.  We still have quite a few devices that need to be
wired up by code.  If you try to device_add such a device, it'll fail
in sometimes mysterious ways.  If you're lucky, you get an
unmysterious immediate crash.

To protect users from such badness, DeviceClass member no_user used to
make device models unavailable with -device / device_add, but that
regressed in commit 18b6dad.  The device model is still omitted from
help, but is available anyway.

Attempts to fix the regression have been rejected with the argument
that the purpose of no_user isn't clear, and it's prone to misuse.

This commit clarifies no_user's purpose.  Anthony suggested to rename
it cannot_instantiate_with_device_add_yet_due_to_internal_bugs, which
I shorten somewhat to keep checkpatch happy.  While there, make it
bool.

Every use of cannot_instantiate_with_device_add_yet gets a FIXME
comment asking for rationale.  The next few commits will clean them
all up, either by providing a rationale, or by getting rid of the use.

With that done, the regression fix is hopefully acceptable.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel.a@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>

7 files changed, 7 insertions, 7 deletions

diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
index a0beb10863..ea420c7188 100644
--- a/hw/intc/apic_common.c
+++ b/hw/intc/apic_common.c
@@ -386,7 +386,7 @@ static void apic_common_class_init(ObjectClass *klass, void *data)
 
     dc->vmsd = &vmstate_apic_common;
     dc->reset = apic_reset_common;
-    dc->no_user = 1;
+    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
     dc->props = apic_properties_common;
     idc->init = apic_init_common;
 }
diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
index d431b7a881..24ad27689d 100644
--- a/hw/intc/arm_gic.c
+++ b/hw/intc/arm_gic.c
@@ -704,7 +704,7 @@ static void arm_gic_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
     ARMGICClass *agc = ARM_GIC_CLASS(klass);
 
-    dc->no_user = 1;
+    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
     agc->parent_realize = dc->realize;
     dc->realize = arm_gic_realize;
 }
diff --git a/hw/intc/arm_gic_common.c b/hw/intc/arm_gic_common.c
index c7658508dd..214a585d9b 100644
--- a/hw/intc/arm_gic_common.c
+++ b/hw/intc/arm_gic_common.c
@@ -156,7 +156,7 @@ static void arm_gic_common_class_init(ObjectClass *klass, void *data)
     dc->realize = arm_gic_common_realize;
     dc->props = arm_gic_common_properties;
     dc->vmsd = &vmstate_gic;
-    dc->no_user = 1;
+    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
 }
 
 static const TypeInfo arm_gic_common_type = {
diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c
index f71397542a..a0bbf12cdb 100644
--- a/hw/intc/arm_gic_kvm.c
+++ b/hw/intc/arm_gic_kvm.c
@@ -150,7 +150,7 @@ static void kvm_arm_gic_class_init(ObjectClass *klass, void *data)
     kgc->parent_reset = dc->reset;
     dc->realize = kvm_arm_gic_realize;
     dc->reset = kvm_arm_gic_reset;
-    dc->no_user = 1;
+    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
 }
 
 static const TypeInfo kvm_arm_gic_info = {
diff --git a/hw/intc/i8259_common.c b/hw/intc/i8259_common.c
index 803d037f68..2acdbfed17 100644
--- a/hw/intc/i8259_common.c
+++ b/hw/intc/i8259_common.c
@@ -135,7 +135,7 @@ static void pic_common_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->vmsd = &vmstate_pic_common;
-    dc->no_user = 1;
+    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
     dc->props = pic_properties_common;
     dc->realize = pic_common_realize;
 }
diff --git a/hw/intc/ioapic_common.c b/hw/intc/ioapic_common.c
index 6b705c1546..cc5a80de9c 100644
--- a/hw/intc/ioapic_common.c
+++ b/hw/intc/ioapic_common.c
@@ -98,7 +98,7 @@ static void ioapic_common_class_init(ObjectClass *klass, void *data)
 
     dc->realize = ioapic_common_realize;
     dc->vmsd = &vmstate_ioapic_common;
-    dc->no_user = 1;
+    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
 }
 
 static const TypeInfo ioapic_common_type = {
diff --git a/hw/intc/pl190.c b/hw/intc/pl190.c
index 329680da3a..b16bc022e7 100644
--- a/hw/intc/pl190.c
+++ b/hw/intc/pl190.c
@@ -273,7 +273,7 @@ static void pl190_class_init(ObjectClass *klass, void *data)
     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 
     k->init = pl190_init;
-    dc->no_user = 1;
+    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
     dc->reset = pl190_reset;
     dc->vmsd = &vmstate_pl190;
 }