uefi-raw: replace ABI-related unit tests with consts checks

This is best practice in the ecosystem and ensures that the ABI is
correct for the target platform - which may be different from the
test platform.

uefi-raw/src/lib.rs

@@ -86,6 +86,14 @@ pub type VirtualAddress = u64;
 #[repr(transparent)]
 pub struct Boolean(pub u8);
 
+// Ensure ABI guarantees for Boolean, as promised in [0].
+//
+// [0]: https://github.com/tianocore/edk2/blob/b0f43dd3fdec2363e3548ec31eb455dc1c4ac761/MdePkg/Include/X64/ProcessorBind.h#L192
+const _: () = {
+    assert!(align_of::<Boolean>() == 1);
+    assert!(size_of::<Boolean>() == 1);
+};
+
 impl Boolean {
     /// [`Boolean`] representing `true`.
     ///
@@ -169,12 +177,10 @@ mod tests {
     use super::*;
 
     #[test]
-    /// Test the properties promised in [0]. This also applies for the other
-    /// architectures.
+    /// Test the properties promised in [0] and convenient rusty conversions.
     ///
     /// [0] https://github.com/tianocore/edk2/blob/b0f43dd3fdec2363e3548ec31eb455dc1c4ac761/MdePkg/Include/X64/ProcessorBind.h#L192
-    fn test_boolean_abi() {
-        assert_eq!(size_of::<Boolean>(), 1);
+    fn test_boolean_conversions() {
         assert_eq!(Boolean::from(true).0, 1);
         assert_eq!(Boolean::from(false).0, 0);
         assert_eq!(Boolean::TRUE.0, 1);

uefi-raw/src/net.rs

@@ -130,6 +130,20 @@ pub union IpAddress {
     pub v6: Ipv6Address,
 }
 
+// Ensure ABI guarantees for IpAddress.
+const _: () = {
+    #[repr(C, packed)]
+    struct PackedHelper<T>(T);
+
+    assert!(align_of::<IpAddress>() == 4);
+    assert!(size_of::<IpAddress>() == 16);
+
+    // The type must be usable in a packed struct, even when it is normally
+    // 4 byte aligned.
+    assert!(align_of::<PackedHelper<IpAddress>>() == 1);
+    assert!(size_of::<PackedHelper<IpAddress>>() == 16);
+};
+
 impl IpAddress {
     /// Zeroed variant where all bytes are guaranteed to be initialized to zero.
     pub const ZERO: Self = Self { addr: [0; 4] };
@@ -355,20 +369,6 @@ mod tests {
         assert_eq!(efi_mac_addr.into_ethernet_addr(), ethernet_octets);
     }
 
-    // Ensure that our IpAddress type can be put into a packed struct,
-    // even when it is normally 4 byte aligned.
-    #[test]
-    fn test_efi_ip_address_abi() {
-        #[repr(C, packed)]
-        struct PackedHelper<T>(T);
-
-        assert_eq!(align_of::<IpAddress>(), 4);
-        assert_eq!(size_of::<IpAddress>(), 16);
-
-        assert_eq!(align_of::<PackedHelper<IpAddress>>(), 1);
-        assert_eq!(size_of::<PackedHelper<IpAddress>>(), 16);
-    }
-
     /// Tests the From-impls from the documentation.
     #[test]
     fn test_promised_from_impls() {

uefi-raw/src/protocol/device_path.rs

@@ -64,6 +64,13 @@ pub struct DevicePathProtocol {
     // followed by payload (dynamically sized)
 }
 
+// Ensure ABI guarantees for DevicePathProtocol. The struct is naturally
+// packed; thus, we don't need to explicitly specify `packed`.
+const _: () = {
+    assert!(size_of::<DevicePathProtocol>() == 4);
+    assert!(align_of::<DevicePathProtocol>() == 1);
+};
+
 impl DevicePathProtocol {
     pub const GUID: Guid = guid!("09576e91-6d3f-11d2-8e39-00a0c969723b");
 
@@ -300,16 +307,3 @@ pub struct DevicePathUtilitiesProtocol {
 impl DevicePathUtilitiesProtocol {
     pub const GUID: Guid = guid!("0379be4e-d706-437d-b037-edb82fb772a4");
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// Test that ensures the struct is packed. Thus, we don't need to
-    /// explicitly specify `packed`.
-    #[test]
-    fn abi() {
-        assert_eq!(size_of::<DevicePathProtocol>(), 4);
-        assert_eq!(align_of::<DevicePathProtocol>(), 1);
-    }
-}