Introducing the windows-link crate

[kennykerr]

This update introduces the windows-link crate as a simpler alternative to the windows-targets crate. It provides the exact same link macro but uses raw-dylib unconditionally and thus has no target-specific dependencies to include import libs. This means that the windows-link crate requires Rust 1.71 or later as that was the first version to stabilize raw-dylib for all Windows targets.

The windows-bindgen crate is also updated to default to use windows-link for functions. You can opt-out by using the new --link option and specify a different module for the link macro. For example, the windows-sys crate continues to use windows-targets as it has an older MSRV. It does so by using the following option bindgen arguments:

--link windows_targets

The windows-targets crate is unchanged and will continue to be updated for the time being to support windows-sys. It continues to support the windows_raw_dylib cfg option for opting in to raw-dylib whereas the new windows-link crate ignores the windows_raw_dylib cfg option and uses raw-dylib in all cases.

As an example, consider the following build script.

windows_bindgen::bindgen(
    "--in default --out src/bindings.rs --flat --sys --filter GetTickCount".split_whitespace(),
);

This will produce the following output:

windows_link::link!("kernel32.dll" "system" fn GetTickCount() -> u32);

Add a dependency on the windows-link crate and you're all set!

You can then use the new --link argument only if you need to change this.

windows_bindgen::bindgen(
    "--in default --out src/bindings.rs --flat --sys --filter GetTickCount --link windows_targets".split_whitespace(),
);

This will produce the following altered output to once again use the windows-targets crate.

windows_targets::link!("kernel32.dll" "system" fn GetTickCount() -> u32);

[ChrisDenton]

Looks great! --link is a really useful feature on its own. And the more we can move toward not needing to bundle binary libs the better.

[ChrisDenton]

This is just a comment but I had to look this up to recall why extern "C" is used instead of $abi. It was rust-lang/rust#110505 which wasn't fixed until 1.77, a fair bit above the current MSRV.

[RalfJung]

No, that cannot be true. rust-lang/rust#110505 got closed by rust-lang/rust#119587 which just adds an unstable feature that's still unstable.

EDIT: See #3672 for more context.