Support dylib on iOS

[drewcrawford]

iOS added support for dynamic libraries in iOS 8. Clang/LLVM can now build them:

$ clang -arch armv7 -arch armv7s -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS8.1.sdk/  -dynamiclib test.c

However rustc cannot:

$ rustc --crate-type dylib --target=armv7-apple-ios test.rs
warning: dropping unsupported crate type `CrateTypeDylib` for target `armv7-apple-ios`

We should support building dylibs on the platform.

[steveklabnik]

Triage: not aware of any changes here

[extrawurst]

This feature would be very appreciated

[holzschu]

Hi,
I'd like to re-up this issue as well. As the original poster said, iOS supports dynamic libraries since iOS 8. It would be great to have rustc support them as well.
Among other things, it is blocking cross-compilation of the Python cryptography module for iOS: pyca/cryptography#5814

[alex]

Is implementing this just a matter of setting dyanmic_linking: true on the target spec, or is there more to it?

[holzschu]

According to this PR, it seems to be, yes: #73516
(it was merged, then pulled later: #77716 )

[alex]

Ok, so as a practical matter this appears to be blocked on rust-lang/cargo#4881

[awakecoding]

Any update on this? I would really like to stop using static libraries only for iOS in projects that use shared libraries on all other platforms

[TCROC]

Any update on this issue?