Supported targets might not need an exact target triple check

[hug-dev]

When we select the bindings that we want, we only check target_arch and target_os. If those two parameters are the only things determining the value of the bindings, then we can simplify this check in build.rs:

        let supported_platforms = vec![
            "x86_64-unknown-linux-gnu".to_string(),
            "aarch64-unknown-linux-gnu".to_string(),
            "armv7-unknown-linux-gnueabi".to_string(),
            "armv7-unknown-linux-gnueabihf".to_string(),
            "arm-unknown-linux-gnueabi".to_string(),
        ];
        let target = std::env::var("TARGET").unwrap();

        // check if target is in the list of supported ones or panic with nice message
        if !supported_platforms.contains(&target) {
            panic!("Compilation target ({}) is not part of the supported targets ({:?}). Please compile with the \"generate-bindings\" feature or add support for your platform :)", target, supported_platforms);
        }

by parsing the target triple as <arch><sub>-<vendor>-<sys>-<abi> (see here) and only checking for the tuple (arch, os).

That would allow much more crates to be used with the generated bindings.

edit: exact same issue on the tss-esapi crate.

[anta5010]

Please notice that ABI might be omitted. For example, Yocto poky sets target as aarch64-poky-linux, x86_64-poky-linux, etc.

[hug-dev]

Related, see:

• Unable to build 0.7.2 for armv7 parsec#378
• Unable to build 0.7.2 for i686 (and ppc64/ppc64le) parsec#379

I am thinking, should we remove that check altogether? I think linking will fail without a harder to decipher message but maybe we can do something about that. That would solve this.

[ionut-arm]

It will fail with a large list of errors that won't be helpful at all - I've already seen it happen on the TSS crate (because of the feature = armv7 instead of arm mistake) :) I think the proposed solution from the top comment is best - checking for (arch, os) tuple instead. We're not going to have an unbounded list of supported triples anyway.