rust/qdev: Test bit property for #property

There's a diference between Rust and C:

Though C macro (e.g., DEFINE_PROP_BIT or DEFINE_PROP_BIT64) always
requires default value, Rust side allows to omit this "default" field
in #property, and provides a default value ("0" - false) for this
field.

This minor difference does not break user habits and should be
acceptable. Therefore, the test cases also cover this scenario.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20250920160520.3699591-10-zhao1.liu@intel.com

diff --git a/rust/qemu-macros/src/tests.rs b/rust/qemu-macros/src/tests.rs
index ec137132ae7d9fad244c7097538862bd8dab09dd..ac998d20e30402b6edc9cfe7a67d80143834f984 100644 (file)
--- a/rust/qemu-macros/src/tests.rs
+++ b/rust/qemu-macros/src/tests.rs
@@ -89,6 +89,19 @@ fn test_derive_device() {
         "Duplicate argument",
         "Already used here",
     );
+    derive_compile_fail!(
+        derive_device_or_error,
+        quote! {
+            #[repr(C)]
+            #[derive(Device)]
+            struct DummyState {
+                #[property(bit = 0, bit = 1)]
+                flags: u32,
+            }
+        },
+        "Duplicate argument",
+        "Already used here",
+    );
     // Check that the field name is preserved when `rename` isn't used:
     derive_compile!(
         derive_device_or_error,
@@ -145,6 +158,92 @@ fn test_derive_device() {
             }
         }
     );
+    // Check that `bit` value is used for the bit property without default
+    // value (note: though C macro (e.g., DEFINE_PROP_BIT) always requires
+    // default value, Rust side allows to default this field to "0"):
+    derive_compile!(
+        derive_device_or_error,
+        quote! {
+            #[repr(C)]
+            #[derive(Device)]
+            pub struct DummyState {
+                parent: ParentField<DeviceState>,
+                #[property(bit = 3)]
+                flags: u32,
+            }
+        },
+        quote! {
+            unsafe impl ::hwcore::DevicePropertiesImpl for DummyState {
+                const PROPERTIES: &'static [::hwcore::bindings::Property] = &[
+                    ::hwcore::bindings::Property {
+                        name: ::std::ffi::CStr::as_ptr(c"flags"),
+                        info: <u32 as ::hwcore::QDevProp>::BIT_INFO,
+                        offset: ::core::mem::offset_of!(DummyState, flags) as isize,
+                        bitnr: 3,
+                        set_default: false,
+                        defval: ::hwcore::bindings::Property__bindgen_ty_1 { u: 0 as u64 },
+                        ..::common::Zeroable::ZERO
+                    }
+                ];
+            }
+        }
+    );
+    // Check that `bit` value is used for the bit property when used:
+    derive_compile!(
+        derive_device_or_error,
+        quote! {
+            #[repr(C)]
+            #[derive(Device)]
+            pub struct DummyState {
+                parent: ParentField<DeviceState>,
+                #[property(bit = 3, default = true)]
+                flags: u32,
+            }
+        },
+        quote! {
+            unsafe impl ::hwcore::DevicePropertiesImpl for DummyState {
+                const PROPERTIES: &'static [::hwcore::bindings::Property] = &[
+                    ::hwcore::bindings::Property {
+                        name: ::std::ffi::CStr::as_ptr(c"flags"),
+                        info: <u32 as ::hwcore::QDevProp>::BIT_INFO,
+                        offset: ::core::mem::offset_of!(DummyState, flags) as isize,
+                        bitnr: 3,
+                        set_default: true,
+                        defval: ::hwcore::bindings::Property__bindgen_ty_1 { u: true as u64 },
+                        ..::common::Zeroable::ZERO
+                    }
+                ];
+            }
+        }
+    );
+    // Check that `bit` value is used for the bit property with rename when used:
+    derive_compile!(
+        derive_device_or_error,
+        quote! {
+            #[repr(C)]
+            #[derive(Device)]
+            pub struct DummyState {
+                parent: ParentField<DeviceState>,
+                #[property(rename = "msi", bit = 3, default = false)]
+                flags: u64,
+            }
+        },
+        quote! {
+            unsafe impl ::hwcore::DevicePropertiesImpl for DummyState {
+                const PROPERTIES: &'static [::hwcore::bindings::Property] = &[
+                    ::hwcore::bindings::Property {
+                        name: ::std::ffi::CStr::as_ptr(c"msi"),
+                        info: <u64 as ::hwcore::QDevProp>::BIT_INFO,
+                        offset: ::core::mem::offset_of!(DummyState, flags) as isize,
+                        bitnr: 3,
+                        set_default: true,
+                        defval: ::hwcore::bindings::Property__bindgen_ty_1 { u: false as u64 },
+                        ..::common::Zeroable::ZERO
+                    }
+                ];
+            }
+        }
+    );
 }
 
 #[test]