Comment by Peter Steinberger (JIRA)

This would make a lot of our API much nicer. Thanks for filing that one!

It's supposed to already do that. Do you have a self-contained example where it isn't?

(Note that NSUInteger could very well be the weirdness here, since that's imported as Int in most-but-not-all positions, and we have to pick which side the typedef falls on.)

It may be something with the NSUInteger. Here is my current workaround where I basically mimic the NSUInteger type:

    #if __LP64__ || (TARGET_OS_EMBEDDED && !TARGET_OS_IPHONE) || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
    typedef unsigned long PageIndex;
    #else
    typedef unsigned int PageIndex;
    #endif

Will try to build self-contained example.

On all the platforms you care about uintptr_t is close enough to NSUInteger to be interoperable. But there's a reason Swift imports NSUInteger as UInt: converting between Int and UInt stinks.

It looks like PageIndex is converted differently than the NSUInteger, and I don't get it.
cannot convert value of type 'PageIndex' (aka 'UInt32') to expected argument type 'UInt'

Certain types are recognized as "word-sized", something that needs information beyond what you get out of a preprocessed C file. long is actually one of them on Apple platforms, but int is not. uintptr_t and NSUInteger both are special-cased to work regardless of their underlying type.

hm... when used uintptr_t

Conflicting return type in implementation of 'pageIndex': 'PSPDFPageIndex' (aka 'unsigned long') vs 'NSUInteger' (aka 'unsigned int')

I mean, you do have to be consistent about it…

I see. I thought you said "uintptr_t is close enough to NSUInteger to be interoperable" meaning it's the same type, but it's not apparently. Ok. I also tried to use API notes with, does it make sense in this case? (couldn't find any docs how it works)

Typedefs:
- Name: "PSPDFPageIndex"
  SwiftBridge: "Swift.UInt"   

and if I look at the generated interface, it's UInt, but it doesn't seem to impact the type checked as it still thinks it's UInt32 eg.

Cannot convert value of type 'PSPDFPageIndex' (aka 'UInt32') to expected argument type 'UInt'

No, sorry, that's not what SwiftBridge is for.

Stepping back, why do you want UInt for this API? That's not standard Swift. If the typedef were imported as Int would you be happy?

I want to do
typedef NSUInteger PageIndex;

Oh, wait, sorry. I got confused because system APIs import NSUInteger as Int. Non-system ones are still UInt. Okay, this is just a bug, then. Leaving it NSUInteger is fine.

@swift-ci create

To add, for the type defined like this:

typedef unsigned long PSPDFUInteger;
typedef PSPDFUInteger PSPDFPageIndex NS_SWIFT_NAME(PageIndex);

And use

- (nullable NSURL *)pathForPageAtIndex:(PSPDFPageIndex)pageIndex;

it's imported as

func pathForPage(at pageIndex: Any!) -> URL?

so it looks like there is something missing with typedef resolving.

Comment by Peter Steinberger (JIRA)

I've tested this with Xcode 11.3.1 (11C505), the importer still has the same issue.