Refactor zinc crate to support native build

[farcaller]

As of now it's not possible to build zinc crate as it uses arm assembly. Still, zinc contains lots of code that would be interesting to unit test and validate coverage.

The proposed solution is to extract all machine-dependent code into new file hierarchy, namely arch/, and allow that to depend on feature flags.

Actual mcu code should be buildable for native arch as it's expected that it would be unit tested as well.

[mcoffin]

Compiling the zinc crate natively works fine for me? cargo test --lib --verbose.

It won't work of you enable one of the platform features, as that will enable that ISR vector code for that platform (and therefore some assembly). Note that the stuff in hal/platform is not gated behind #[cfg(feature = "platform")] and can therefore be unit tested if you can find a way to get it to use dummy registers.

[farcaller]

That's for test only, no? I mean, compile the dylib/rlib of zinc for native target.

[farcaller]

Also, #302 will sort out the dummy registers part.

[bharrisau]

I think the #cfgs for the asm code is currently just for tests. But
moving all of the unsafe ASM to a separate mod and documenting it (so we
don't get asm popping up everywhere) would be a good thing for hygiene.
On 2 Jun 2015 6:14 am, "Vladimir Pouzanov" [email protected] wrote:

Also, #302 #302 will sort out the
dummy registers part.

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#303 (comment).

[mcoffin]

@bharrisau Regarding what you said in #305, i think a decent solution might be to come up with a system like rustc's "lang items". Then, i would agree, #[cfg(...)] to import the right impl (maybe within some intrinsics mod?)

[farcaller]

a system like rustc's "lang items"

would be nice, but the only way to implement something like it, as far as I know, is to have a stable path and pub use the #[cfg]-guarded version into it.

[mcoffin]

Note for self and anyone reading: the zinc crate will now build for native, but that's just because all the mcu code sits behind cargo feature gates.