Support for `__aarch64__` flag

[lmtr0]

As pointed out in https://github.com/briansmith/ring/issues/1442 it appears that the o64h-clang is not setting any arm flags:

[tpoechtrager]

OS? Clang compiler version?

[lmtr0]

Well clang was 13 and the os i tested was arch Linux container but it also doesn't work in Ubuntu, Manjaro and fedora with MacOS SDK 11.3

[lmtr0]

I was compiling a project in rust that had dependency in ring which is the crate broke the build. Btw starting the compilation with system clang fails but then switching to osxcross then works

[JimChenWYU]

how about it? I met the same error, can not compile briansmith/ring

[lmtr0]

use -Daarch64

[lmtr0]

in .cargo/config.toml:

[target.aarch64-apple-darwin]
rustflags = ["-C", "link-args=-D__aarch64__"]
linker = "o64h-clang"
ar = "aarch64-apple-darwin20.4-ar"

[JimChenWYU]

@lmtr0 got same error I had run cargo clean

.cargo/config.toml

[build]
target = "aarch64-apple-darwin"

[target.aarch64-apple-darwin]
rustflags = ["-C", "link-args=-D__aarch64__"]
linker = "/osxcross/bin/aarch64-apple-darwin20.4-clang"
ar = "/osxcross/bin/aarch64-apple-darwin20.4-ar"

o64h-clang I found it is same as /osxcross/bin/aarch64-apple-darwin20.4-clang

[lmtr0]

can you switch to sodiumoxide? I did that since I couldn't solve it

[JimChenWYU]

I can not, it's not my application depend on ring, it's other package

[lmtr0]

Sorry then, this sounds to be a problem with the compiler.... maybe @tpoechtrager can help more, I just switched to libsodium cause I couldn't solve it then and I can't solve it now

[briansmith]

The latest version of ring (0.17.0) doesn't use __aarch64__ any more. It uses __ARM_ARCH. If clang isn't defining these automatically __ARM_ARCH for an aarch64-* target then there is indeed something wrong.