[PATCH 16/26] rust: qom: change the parent type to an associated type

[Paolo Bonzini]

Avoid duplicated code to retrieve the QOM type strings from the
Rust type.

Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
 rust/hw/char/pl011/src/device.rs | 6 ++++--
 rust/qemu-api/src/definitions.rs | 8 ++------
 rust/qemu-api/tests/tests.rs     | 3 +--
 3 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/rust/hw/char/pl011/src/device.rs b/rust/hw/char/pl011/src/device.rs
index 0ab825b1ca4..3e29442a625 100644
--- a/rust/hw/char/pl011/src/device.rs
+++ b/rust/hw/char/pl011/src/device.rs
@@ -113,7 +113,8 @@ unsafe impl ObjectType for PL011State {
 }
 
 impl ObjectImpl for PL011State {
-    const PARENT_TYPE_NAME: Option<&'static CStr> = Some(<SysBusDevice as 
ObjectType>::TYPE_NAME);
+    type ParentType = SysBusDevice;
+
     const INSTANCE_INIT: Option<unsafe fn(&mut Self)> = Some(Self::init);
 }
 
@@ -650,7 +651,8 @@ unsafe impl ObjectType for PL011Luminary {
 }
 
 impl ObjectImpl for PL011Luminary {
-    const PARENT_TYPE_NAME: Option<&'static CStr> = Some(<PL011State as 
ObjectType>::TYPE_NAME);
+    type ParentType = PL011State;
+
     const INSTANCE_INIT: Option<unsafe fn(&mut Self)> = Some(Self::init);
 }
 
diff --git a/rust/qemu-api/src/definitions.rs b/rust/qemu-api/src/definitions.rs
index 1c412dbc876..1975ad91867 100644
--- a/rust/qemu-api/src/definitions.rs
+++ b/rust/qemu-api/src/definitions.rs
@@ -57,7 +57,7 @@ pub unsafe trait ObjectType: Sized {
 pub trait ObjectImpl: ObjectType + ClassInitImpl {
     /// The parent of the type.  This should match the first field of
     /// the struct that implements `ObjectImpl`:
-    const PARENT_TYPE_NAME: Option<&'static CStr>;
+    type ParentType: ObjectType;
 
     /// Whether the object can be instantiated
     const ABSTRACT: bool = false;
@@ -76,11 +76,7 @@ pub trait ObjectImpl: ObjectType + ClassInitImpl {
 
     const TYPE_INFO: TypeInfo = TypeInfo {
         name: Self::TYPE_NAME.as_ptr(),
-        parent: if let Some(pname) = Self::PARENT_TYPE_NAME {
-            pname.as_ptr()
-        } else {
-            core::ptr::null_mut()
-        },
+        parent: Self::ParentType::TYPE_NAME.as_ptr(),
         instance_size: core::mem::size_of::<Self>(),
         instance_align: core::mem::align_of::<Self>(),
         instance_init: match Self::INSTANCE_INIT {
diff --git a/rust/qemu-api/tests/tests.rs b/rust/qemu-api/tests/tests.rs
index 1be03eb685c..2a72b0f9276 100644
--- a/rust/qemu-api/tests/tests.rs
+++ b/rust/qemu-api/tests/tests.rs
@@ -53,8 +53,7 @@ unsafe impl ObjectType for DummyState {
     }
 
     impl ObjectImpl for DummyState {
-        const PARENT_TYPE_NAME: Option<&'static CStr> =
-            Some(<DeviceState as ObjectType>::TYPE_NAME);
+        type ParentType = DeviceState;
         const ABSTRACT: bool = false;
     }
 
-- 
2.47.1