Tier System: `aarch64(_be)-linux`

[andrewrk]

Once all these items are complete, we can say that Zig has Tier 1 support for 64-bit ARM Linux.

• make sure we can build-exe with -target aarch64v8-linux-gnu
• make sure we can build-exe with -target aarch64v8-linux-musleabi
  • lld: error: undefined symbol: __floatsitf - I believe this is the last one! Missing compiler_rt functions #1290
• make sure stack traces / debug info works & add test coverage
• add the target to the test matrix
• get the full test suite passing
• figure out a 64-bit arm linux continuous integration testing service and hook it up to zig's CI testing.

[sepruitt]

Hello, I'm interested in this because I'm attempting an Android port of zig. I see that there are at least two free AArch64 linux CI services for OSS projects, Shippable and Drone. One of those can probably be set up once the test suite passes.

[SamTebbs33]

Hello, I'm interested in this because I'm attempting an Android port of zig. I see that there are at least two free AArch64 linux CI services for OSS projects, Shippable and Drone. One of those can probably be set up once the test suite passes.

Thanks for finding those @sepruitt , I'll take a look at them once we have the tests passing, which I'm currently setting up a docker image for.

[shawnl]

So things have gone backwards with the addition of libuserland.a. Better support of the C ABI is now necessary in order to get things working again. http://infocenter.arm.com/help/topic/com.arm.doc.ihi0055b/IHI0055B_aapcs64.pdf

[andrewrk]

@shawnl Thanks for the notice. Looks like doing #661 would serve us well right now.

We do have C ABI tests in test/stage1/c_abi/ but right now the tests are disabled for non x86_64 architectures:

zig/test/build_examples.zig

Lines 26 to 28 in d83b15f

	if (builtin.arch == builtin.Arch.x86_64) { // TODO add C ABI support for other architectures
	cases.addBuildFile("test/stage1/c_abi/build.zig");
	}

So I think the path forward here is

• use a builtin enum for calling conventions instead of keywords #661
• get the C ABI tests passing for aarch64
• add C ABI tests for aapcs calling convention

[markfirmware]

FYI https://github.com/WorksOnArm/cluster
I might be able to help.

[SamTebbs33]

FYI https://github.com/WorksOnArm/cluster
I might be able to help.

Thanks @markfirmware, looks like we'll have to submit an access request similar to https://github.com/WorksOnArm/cluster/issues/165

[shawnl]

The biggest problem I ran into when trying to do this is the high memory requirements of the stage1 compiler, which means a much more expensive VPS.

[markfirmware]

I can see that @shawnl has a ball rolling over at #2978.