IOUSBHostCIMessageStatus has the wrong type/encoding

[carlossless]

Hi,

I'm experiencing a panic, when trying to use [IOUSBHostCIControllerStateMachine respondToCommand:status:error:] and passing IOUSBHostCIMessageStatus::Success for the status argument. Here's the message I receive:

[IOUSBHostCIControllerStateMachine respondToCommand:status:error:]: expected argument at index 1 to have type code 'i', but found 'I'

Enabling the feature relax-sign-encoding can be a workaround, but in order to actually fix this, the ENCODING (and underlying type) for IOUSBHostCIMessageStatus should be changed from c_uint to c_int.

[carlossless]

Just encountered the same issue with:

• IOUSBHostCILinkState
• IOUSBHostCIDeviceSpeed
• IOUSBHostCIEndpointState

[madsmtm]

Indeed, the following program returns i and not I.

#import <IOUSBHost/IOUSBHost.h>

int main() {
    printf("%s\n", @encode(IOUSBHostCIMessageStatus));
    return 0;
}

I'm unsure why header-translator thinks that it should treat it as c_uint, probably some faulty logic somewhere in https://github.com/madsmtm/objc2/blob/c589b66f7fe5e7705138758f3612105d39eb1f42/crates/header-translator/src/stmt.rs#L1357-L1502

[carlossless]

Well, clang_getEnumDeclIntegerType definitely returns unsigned int for these types, but I'm not sure what makes clang think this way...

[madsmtm]

Possibly it's the = 0 on IOUSBHostCIMessageStatusReserved? I'm unsure :/

[pronebird]

Swift also thinks it's UInt32 https://developer.apple.com/documentation/iousbhost/iousbhostcimessagestatus

[carlossless]

Hm, perhaps it's just a difference in how @encode and clang see these types and there's nothing actually wrong here.

I wonder if these cases could be detected and encoding requirements relaxed when calling methods that accept these types... 🤔

[pronebird]

@carlossless I found the following SO issue which says that the behaviour of modern C compiler has changed 🤯

[madsmtm]

Btw, I think you can work around it with:

# Cargo.toml
[dependencies]
objc2 = { version = "0.6.1", features = ["relax-sign-encoding"] }