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 <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-15-armbru@redhat.com>
[Two semantic rebase conflicts resolved]

6 files changed, 21 insertions, 25 deletions

diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index 76aaa7a8d8..937db10ae6 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -510,42 +510,39 @@ static void microvm_class_init(ObjectClass *oc, void *data)
     object_class_property_add(oc, MICROVM_MACHINE_PIC, "OnOffAuto",
                               microvm_machine_get_pic,
                               microvm_machine_set_pic,
-                              NULL, NULL, &error_abort);
+                              NULL, NULL);
     object_class_property_set_description(oc, MICROVM_MACHINE_PIC,
         "Enable i8259 PIC");
 
     object_class_property_add(oc, MICROVM_MACHINE_PIT, "OnOffAuto",
                               microvm_machine_get_pit,
                               microvm_machine_set_pit,
-                              NULL, NULL, &error_abort);
+                              NULL, NULL);
     object_class_property_set_description(oc, MICROVM_MACHINE_PIT,
         "Enable i8254 PIT");
 
     object_class_property_add(oc, MICROVM_MACHINE_RTC, "OnOffAuto",
                               microvm_machine_get_rtc,
                               microvm_machine_set_rtc,
-                              NULL, NULL, &error_abort);
+                              NULL, NULL);
     object_class_property_set_description(oc, MICROVM_MACHINE_RTC,
         "Enable MC146818 RTC");
 
     object_class_property_add_bool(oc, MICROVM_MACHINE_ISA_SERIAL,
                                    microvm_machine_get_isa_serial,
-                                   microvm_machine_set_isa_serial,
-                                   &error_abort);
+                                   microvm_machine_set_isa_serial);
     object_class_property_set_description(oc, MICROVM_MACHINE_ISA_SERIAL,
         "Set off to disable the instantiation an ISA serial port");
 
     object_class_property_add_bool(oc, MICROVM_MACHINE_OPTION_ROMS,
                                    microvm_machine_get_option_roms,
-                                   microvm_machine_set_option_roms,
-                                   &error_abort);
+                                   microvm_machine_set_option_roms);
     object_class_property_set_description(oc, MICROVM_MACHINE_OPTION_ROMS,
         "Set off to disable loading option ROMs");
 
     object_class_property_add_bool(oc, MICROVM_MACHINE_AUTO_KERNEL_CMDLINE,
                                    microvm_machine_get_auto_kernel_cmdline,
-                                   microvm_machine_set_auto_kernel_cmdline,
-                                   &error_abort);
+                                   microvm_machine_set_auto_kernel_cmdline);
     object_class_property_set_description(oc,
         MICROVM_MACHINE_AUTO_KERNEL_CMDLINE,
         "Set off to disable adding virtio-mmio devices to the kernel cmdline");
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 21d4a8ec3a..33cf14363a 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -662,7 +662,7 @@ void pc_cmos_init(PCMachineState *pcms,
                              TYPE_ISA_DEVICE,
                              (Object **)&x86ms->rtc,
                              object_property_allow_set_link,
-                             OBJ_PROP_LINK_STRONG, &error_abort);
+                             OBJ_PROP_LINK_STRONG);
     object_property_set_link(OBJECT(pcms), OBJECT(s),
                              "rtc_state", &error_abort);
 
@@ -1965,22 +1965,22 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
 
     object_class_property_add(oc, PC_MACHINE_DEVMEM_REGION_SIZE, "int",
         pc_machine_get_device_memory_region_size, NULL,
-        NULL, NULL, &error_abort);
+        NULL, NULL);
 
     object_class_property_add(oc, PC_MACHINE_VMPORT, "OnOffAuto",
         pc_machine_get_vmport, pc_machine_set_vmport,
-        NULL, NULL, &error_abort);
+        NULL, NULL);
     object_class_property_set_description(oc, PC_MACHINE_VMPORT,
         "Enable vmport (pc & q35)");
 
     object_class_property_add_bool(oc, PC_MACHINE_SMBUS,
-        pc_machine_get_smbus, pc_machine_set_smbus, &error_abort);
+        pc_machine_get_smbus, pc_machine_set_smbus);
 
     object_class_property_add_bool(oc, PC_MACHINE_SATA,
-        pc_machine_get_sata, pc_machine_set_sata, &error_abort);
+        pc_machine_get_sata, pc_machine_set_sata);
 
     object_class_property_add_bool(oc, PC_MACHINE_PIT,
-        pc_machine_get_pit, pc_machine_set_pit, &error_abort);
+        pc_machine_get_pit, pc_machine_set_pit);
 }
 
 static const TypeInfo pc_machine_info = {
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 3862e5120e..f66e1d73ce 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -291,7 +291,7 @@ static void pc_init1(MachineState *machine,
                                  TYPE_HOTPLUG_HANDLER,
                                  (Object **)&pcms->acpi_dev,
                                  object_property_allow_set_link,
-                                 OBJ_PROP_LINK_STRONG, &error_abort);
+                                 OBJ_PROP_LINK_STRONG);
         object_property_set_link(OBJECT(machine), OBJECT(piix4_pm),
                                  PC_MACHINE_ACPI_DEVICE_PROP, &error_abort);
     }
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 3349e38a4c..4ba8ac8774 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -214,7 +214,7 @@ static void pc_q35_init(MachineState *machine)
     /* create pci host bus */
     q35_host = Q35_HOST_DEVICE(qdev_create(NULL, TYPE_Q35_HOST_DEVICE));
 
-    object_property_add_child(qdev_get_machine(), "q35", OBJECT(q35_host), NULL);
+    object_property_add_child(qdev_get_machine(), "q35", OBJECT(q35_host));
     object_property_set_link(OBJECT(q35_host), OBJECT(ram_memory),
                              MCH_HOST_PROP_RAM_MEM, NULL);
     object_property_set_link(OBJECT(q35_host), OBJECT(pci_memory),
@@ -240,7 +240,7 @@ static void pc_q35_init(MachineState *machine)
                              TYPE_HOTPLUG_HANDLER,
                              (Object **)&pcms->acpi_dev,
                              object_property_allow_set_link,
-                             OBJ_PROP_LINK_STRONG, &error_abort);
+                             OBJ_PROP_LINK_STRONG);
     object_property_set_link(OBJECT(machine), OBJECT(lpc),
                              PC_MACHINE_ACPI_DEVICE_PROP, &error_abort);
 
diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index f5f3f466b0..002133a2d8 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -90,10 +90,9 @@ static PFlashCFI01 *pc_pflash_create(PCMachineState *pcms,
     qdev_prop_set_uint64(dev, "sector-length", FLASH_SECTOR_SIZE);
     qdev_prop_set_uint8(dev, "width", 1);
     qdev_prop_set_string(dev, "name", name);
-    object_property_add_child(OBJECT(pcms), name, OBJECT(dev),
-                              &error_abort);
+    object_property_add_child(OBJECT(pcms), name, OBJECT(dev));
     object_property_add_alias(OBJECT(pcms), alias_prop_name,
-                              OBJECT(dev), "drive", &error_abort);
+                              OBJECT(dev), "drive");
     return PFLASH_CFI01(dev);
 }
 
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index e2bf601273..7a3bc7ab66 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -350,7 +350,7 @@ void ioapic_init_gsi(GSIState *gsi_state, const char *parent_name)
         dev = qdev_create(NULL, TYPE_IOAPIC);
     }
     object_property_add_child(object_resolve_path(parent_name, NULL),
-                              "ioapic", OBJECT(dev), NULL);
+                              "ioapic", OBJECT(dev));
     qdev_init_nofail(dev);
     d = SYS_BUS_DEVICE(dev);
     sysbus_mmio_map(d, 0, IO_APIC_DEFAULT_ADDRESS);
@@ -982,19 +982,19 @@ static void x86_machine_class_init(ObjectClass *oc, void *data)
 
     object_class_property_add(oc, X86_MACHINE_MAX_RAM_BELOW_4G, "size",
         x86_machine_get_max_ram_below_4g, x86_machine_set_max_ram_below_4g,
-        NULL, NULL, &error_abort);
+        NULL, NULL);
     object_class_property_set_description(oc, X86_MACHINE_MAX_RAM_BELOW_4G,
         "Maximum ram below the 4G boundary (32bit boundary)");
 
     object_class_property_add(oc, X86_MACHINE_SMM, "OnOffAuto",
         x86_machine_get_smm, x86_machine_set_smm,
-        NULL, NULL, &error_abort);
+        NULL, NULL);
     object_class_property_set_description(oc, X86_MACHINE_SMM,
         "Enable SMM");
 
     object_class_property_add(oc, X86_MACHINE_ACPI, "OnOffAuto",
         x86_machine_get_acpi, x86_machine_set_acpi,
-        NULL, NULL, &error_abort);
+        NULL, NULL);
     object_class_property_set_description(oc, X86_MACHINE_ACPI,
         "Enable ACPI");
 }