Added tvOS support

[ErikEverson]

Added support to build tvOS targets so that consumers of rustls-platform-verifier can use it with tvOS devices

Target support added for:

• x86_64-apple-tvos
• aarch64-apple-tvos
• aarch64-apple-tvos-sim

Motivation:

• We are adding support for tvOS to our library and consuming iOS application that relies on this Rust dependency directly.

How was this tested:

• cargo test (passed)
• cargo +nightly build -Z build-std --lib --target x86_64-apple-tvos -v
• cargo +nightly build -Z build-std --lib --target aarch64-apple-tvos-v
• cargo +nightly build -Z build-std --lib --target aarch64-apple-tvos-sim -v

[complexspaces]

Is it possible to add a CI job that at least runs our Clippy checks on the tvOS target? It would be nice if this didn't regress quietly by mistake.

[cpu]

I think it's part of why this PR is marked a draft, but just to be explicit it would also be great if you could tidy up the commit history when you add the CI coverage. Thank you!

[ErikEverson]

@complexspaces I looked into adding a clippy ci job for tvOS I am not sure if Clippy can easily be run or at all on tier 3 targets. https://github.com/rust-lang/rust-clippy/issues/4573#issuecomment-535521420

• It might be possible but requires building rustc https://github.com/rust-lang/rust-clippy/issues/5270#issuecomment-999537999

Also I looked into running just Check which is not as good as Clippy but at least something. I was able to get cargo +nightly -Zbuild-std check --target aarch64-apple-tvos to work.

[complexspaces]

@ErikEverson Thanks for taking an initial look at that! I checked out this branch locally, and I think that I was able to get Clippy to work on a recent nightly. Could you see if this is reproducible for you as well? I'm on an M1 macOS 14 system.

These are my versions:

cargo +nightly --version
cargo 1.79.0-nightly (0637083df 2024-04-02)

rustc +nightly --version
rustc 1.79.0-nightly (385fa9d84 2024-04-04)

Running cargo clean and then cargo +nightly clippy -Zbuild-std --target aarch64-apple-tvos completes in a few seconds after building the standard library. I tested its functionality by adding #![warn(clippy::as_conversions)] to lib.rs and then removing the #[allow(clippy::as_conversions)] annotation on system_time_to_cfdate. After running it again the warnings I'd expect appeared:

warning: using a potentially dangerous silent `as` conversion
  --> rustls-platform-verifier/src/verification/apple.rs:32:36
   |
32 |     let unix_adjustment = unsafe { kCFAbsoluteTimeIntervalSince1970 as u64 };
   |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider using a safe wrapper for this conversion
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#as_conversions
note: the lint level is defined here
  --> rustls-platform-verifier/src/lib.rs:4:9
   |
4  | #![warn(clippy::as_conversions)]
   |         ^^^^^^^^^^^^^^^^^^^^^^

If -Zbuild-std is placed before clippy in the command it fails to work though.

[ErikEverson]

@complexspaces Awesome I will see if I get the same on my side. I was putting -Zbuild-std first. Then I will get a CI clippy working

[cpu]

ErikEverson force-pushed the EE/tvOS_support branch from 80cd835 to e9dc1b9

Thanks! Commit history is looking better. A couple suggestions:

• I think rather than take the git dependency temporarily and then bumping the sec-framework dep versions separately it'd be best to do that all in one commit.
• Similarly, the fmt fix should get folded into commit that introduced the change being reformatted.

So the end state would be something like:

• One commit updating the required deps, adding the new cfg gates, and correctly formatted with cargo fmt.
• One commit updating CI.

[ErikEverson]

@cpu @complexspaces I got clippy to work locally and on CI. One quick question should I run clippy against all tvOS targets or just one like iOS currently is? tvOS targets:

• aarch64-apple-tvos
• aarch64-apple-tvos-sim
• x86_64-apple-tvos

iOS targets:

• aarch64-apple-ios
• aarch64-apple-ios-sim
• x86_64-apple-ios (only one with clippy ran)

[cpu]

One quick question should I run clippy against all tvOS targets or just one like iOS currently is?

I don't feel strongly. Matching the existing iOS target seems sensible to me.

[complexspaces]

I also don't think this matters too much, so let's just target the one like iOS does. We don't have any architecture or environment specific code in rustls-platform-verifier so it shouldn't make a difference to coverage.

[cpu]

I will start preparing a point release :rocket:

[cpu]

This was included in v/0.3.1.