lib.systems: accept *-unknown-elf triples

[alyssais]

Description of changes

These are the canonical GNU triples for various embedded targets. Previously, we only accepted the LLVM-style *-none-elf, which was problematic, because a Matrix user reported needing riscv64-unknown-elf-gcc for some software, and it makes sense for us to be able to produce that. Nixpkgs used to accept such triples, but it was broken by 3b32c92.

With this change, both forms are accepted, and parse equally. Tested that riscv64-unknown-elf is now parsed correctly, and all examples still evaluate.

Link: #165836
Fixes: 3b32c92 ("systems/parse.nix: support eabihf")

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.05 Release Notes (or backporting 22.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[GenericNerdyUsername]

works for me, but I am confused by line 438

[alyssais]

works for me, but I am confused by line 438

That just defaults the "kernel" attribute to "none" if it doesn't end up being set by the last field of the triple (because it encodes ABI instead).

[GenericNerdyUsername]

ok, got it

[ghost]

Hey thank you for noticing this -- it definitely needs to be fixed, we should be accepting *-unknown-elf.

However this PR has other effects that I'm still trying to understand. For example, it changes the canonicalization of certain triples, like riscv64-none-wasi:

$ /nix/store/b1ch29sg88jggcgs9j1cbb5j2bj62vf7-source/config.sub riscv64-none-wasi
riscv64-none-wasi
$ nix eval --json --impure --expr 'with import ./lib; (systems.elaborate "riscv64-none-wasi").config'
"riscv64-unknown-wasi"

I would like to add a regression test suite to lib/tests/ that verifies that we're parsing triples the same way gnu-config does, except in those cases where we've consciously decided not to (for example ghcjs). I made one when I wrote #180964 except that it checked against the previous behavior of the function rather than against gnu-config-plus-deliberate-exceptions.

Can this PR wait until after I have a chance to add that?

If not, a safe temporary fix might be to just kludge a special case if .. then .. else in at the top of the 3= attrval that checks for this one condition (*-unknown-elf) so we know that nothing else is affected.

Once I have the regression tests working it will be a lot easier to finish cleaning up the mess here (thank you for starting that process!) without having to worry about unexpected effects.

[ghost]

I would like to add a regression test suite to lib/tests/ that verifies that we're parsing triples the same way gnu-config does, except in those cases where we've consciously decided not to

WIP is at #235230

[ghost]

Thank you again for being so patient.

I cherry-picked this on top of #235230 at 66b29b1 and got the following disagreements with gnu-config's handling.

I'll take a closer look at these in the morning. Dealing with missing/unknown vendor fields is the most convoluted part of gnu-config... :(

[
  {
    "expected": "aarch64-none-eabi",
    "name": "testTripleFromString_aarch64-none-eabi",
    "result": "aarch64-unknown-none-eabi"
  },
  {
    "expected": "aarch64-none-eabihf",
    "name": "testTripleFromString_aarch64-none-eabihf",
    "result": "aarch64-unknown-none-eabihf"
  },
  {
    "expected": "aarch64_be-none-eabi",
    "name": "testTripleFromString_aarch64_be-none-eabi",
    "result": "aarch64_be-unknown-none-eabi"
  },
  {
    "expected": "aarch64_be-none-eabihf",
    "name": "testTripleFromString_aarch64_be-none-eabihf",
    "result": "aarch64_be-unknown-none-eabihf"
  },
  {
    "expected": "alpha-none-eabi",
    "name": "testTripleFromString_alpha-none-eabi",
    "result": "alpha-unknown-none-eabi"
  },
  {
    "expected": "alpha-none-eabihf",
    "name": "testTripleFromString_alpha-none-eabihf",
    "result": "alpha-unknown-none-eabihf"
  },
  {
    "expected": "arm-none-eabi",
    "name": "testTripleFromString_arm-none-eabi",
    "result": "arm-unknown-none-eabi"
  },
  {
    "expected": "arm-none-eabihf",
    "name": "testTripleFromString_arm-none-eabihf",
    "result": "arm-unknown-none-eabihf"
  },
  {
    "expected": "armv5tel-none-eabi",
    "name": "testTripleFromString_armv5tel-none-eabi",
    "result": "armv5tel-unknown-none-eabi"
  },
  {
    "expected": "armv5tel-none-eabihf",
    "name": "testTripleFromString_armv5tel-none-eabihf",
    "result": "armv5tel-unknown-none-eabihf"
  },
  {
    "expected": "armv6l-none-eabi",
    "name": "testTripleFromString_armv6l-none-eabi",
    "result": "armv6l-unknown-none-eabi"
  },
  {
    "expected": "armv6l-none-eabihf",
    "name": "testTripleFromString_armv6l-none-eabihf",
    "result": "armv6l-unknown-none-eabihf"
  },
  {
    "expected": "armv6m-none-eabi",
    "name": "testTripleFromString_armv6m-none-eabi",
    "result": "armv6m-unknown-none-eabi"
  },
  {
    "expected": "armv6m-none-eabihf",
    "name": "testTripleFromString_armv6m-none-eabihf",
    "result": "armv6m-unknown-none-eabihf"
  },
  {
    "expected": "armv7a-none-eabi",
    "name": "testTripleFromString_armv7a-none-eabi",
    "result": "armv7a-unknown-none-eabi"
  },
  {
    "expected": "armv7a-none-eabihf",
    "name": "testTripleFromString_armv7a-none-eabihf",
    "result": "armv7a-unknown-none-eabihf"
  },
  {
    "expected": "armv7l-none-eabi",
    "name": "testTripleFromString_armv7l-none-eabi",
    "result": "armv7l-unknown-none-eabi"
  },
  {
    "expected": "armv7l-none-eabihf",
    "name": "testTripleFromString_armv7l-none-eabihf",
    "result": "armv7l-unknown-none-eabihf"
  },
  {
    "expected": "armv7m-none-eabi",
    "name": "testTripleFromString_armv7m-none-eabi",
    "result": "armv7m-unknown-none-eabi"
  },
  {
    "expected": "armv7m-none-eabihf",
    "name": "testTripleFromString_armv7m-none-eabihf",
    "result": "armv7m-unknown-none-eabihf"
  },
  {
    "expected": "armv7r-none-eabi",
    "name": "testTripleFromString_armv7r-none-eabi",
    "result": "armv7r-unknown-none-eabi"
  },
  {
    "expected": "armv7r-none-eabihf",
    "name": "testTripleFromString_armv7r-none-eabihf",
    "result": "armv7r-unknown-none-eabihf"
  },
  {
    "expected": "armv8a-none-eabi",
    "name": "testTripleFromString_armv8a-none-eabi",
    "result": "armv8a-unknown-none-eabi"
  },
  {
    "expected": "armv8a-none-eabihf",
    "name": "testTripleFromString_armv8a-none-eabihf",
    "result": "armv8a-unknown-none-eabihf"
  },
  {
    "expected": "armv8m-none-eabi",
    "name": "testTripleFromString_armv8m-none-eabi",
    "result": "armv8m-unknown-none-eabi"
  },
  {
    "expected": "armv8m-none-eabihf",
    "name": "testTripleFromString_armv8m-none-eabihf",
    "result": "armv8m-unknown-none-eabihf"
  },
  {
    "expected": "armv8r-none-eabi",
    "name": "testTripleFromString_armv8r-none-eabi",
    "result": "armv8r-unknown-none-eabi"
  },
  {
    "expected": "armv8r-none-eabihf",
    "name": "testTripleFromString_armv8r-none-eabihf",
    "result": "armv8r-unknown-none-eabihf"
  },
  {
    "expected": "avr-none-eabi",
    "name": "testTripleFromString_avr-none-eabi",
    "result": "avr-unknown-none-eabi"
  },
  {
    "expected": "avr-none-eabihf",
    "name": "testTripleFromString_avr-none-eabihf",
    "result": "avr-unknown-none-eabihf"
  },
  {
    "expected": "i386-none-eabi",
    "name": "testTripleFromString_i386-none-eabi",
    "result": "i386-unknown-none-eabi"
  },
  {
    "expected": "i386-none-eabihf",
    "name": "testTripleFromString_i386-none-eabihf",
    "result": "i386-unknown-none-eabihf"
  },
  {
    "expected": "i486-none-eabi",
    "name": "testTripleFromString_i486-none-eabi",
    "result": "i486-unknown-none-eabi"
  },
  {
    "expected": "i486-none-eabihf",
    "name": "testTripleFromString_i486-none-eabihf",
    "result": "i486-unknown-none-eabihf"
  },
  {
    "expected": "i586-none-eabi",
    "name": "testTripleFromString_i586-none-eabi",
    "result": "i586-unknown-none-eabi"
  },
  {
    "expected": "i586-none-eabihf",
    "name": "testTripleFromString_i586-none-eabihf",
    "result": "i586-unknown-none-eabihf"
  },
  {
    "expected": "i686-none-eabi",
    "name": "testTripleFromString_i686-none-eabi",
    "result": "i686-unknown-none-eabi"
  },
  {
    "expected": "i686-none-eabihf",
    "name": "testTripleFromString_i686-none-eabihf",
    "result": "i686-unknown-none-eabihf"
  },
  {
    "expected": "loongarch64-none-eabi",
    "name": "testTripleFromString_loongarch64-none-eabi",
    "result": "loongarch64-unknown-none-eabi"
  },
  {
    "expected": "loongarch64-none-eabihf",
    "name": "testTripleFromString_loongarch64-none-eabihf",
    "result": "loongarch64-unknown-none-eabihf"
  },
  {
    "expected": "m68k-none-eabi",
    "name": "testTripleFromString_m68k-none-eabi",
    "result": "m68k-unknown-none-eabi"
  },
  {
    "expected": "m68k-none-eabihf",
    "name": "testTripleFromString_m68k-none-eabihf",
    "result": "m68k-unknown-none-eabihf"
  },
  {
    "expected": "microblaze-none-eabi",
    "name": "testTripleFromString_microblaze-none-eabi",
    "result": "microblaze-xilinx-none-eabi"
  },
  {
    "expected": "microblaze-none-eabihf",
    "name": "testTripleFromString_microblaze-none-eabihf",
    "result": "microblaze-xilinx-none-eabihf"
  },
  {
    "expected": "microblazeel-none-eabi",
    "name": "testTripleFromString_microblazeel-none-eabi",
    "result": "microblazeel-xilinx-none-eabi"
  },
  {
    "expected": "microblazeel-none-eabihf",
    "name": "testTripleFromString_microblazeel-none-eabihf",
    "result": "microblazeel-xilinx-none-eabihf"
  },
  {
    "expected": "mips-none-eabi",
    "name": "testTripleFromString_mips-none-eabi",
    "result": "mips-unknown-none-eabi"
  },
  {
    "expected": "mips-none-eabihf",
    "name": "testTripleFromString_mips-none-eabihf",
    "result": "mips-unknown-none-eabihf"
  },
  {
    "expected": "mips64-none-eabi",
    "name": "testTripleFromString_mips64-none-eabi",
    "result": "mips64-unknown-none-eabi"
  },
  {
    "expected": "mips64-none-eabihf",
    "name": "testTripleFromString_mips64-none-eabihf",
    "result": "mips64-unknown-none-eabihf"
  },
  {
    "expected": "mips64el-none-eabi",
    "name": "testTripleFromString_mips64el-none-eabi",
    "result": "mips64el-unknown-none-eabi"
  },
  {
    "expected": "mips64el-none-eabihf",
    "name": "testTripleFromString_mips64el-none-eabihf",
    "result": "mips64el-unknown-none-eabihf"
  },
  {
    "expected": "mipsel-none-eabi",
    "name": "testTripleFromString_mipsel-none-eabi",
    "result": "mipsel-unknown-none-eabi"
  },
  {
    "expected": "mipsel-none-eabihf",
    "name": "testTripleFromString_mipsel-none-eabihf",
    "result": "mipsel-unknown-none-eabihf"
  },
  {
    "expected": "mmix-none-eabi",
    "name": "testTripleFromString_mmix-none-eabi",
    "result": "mmix-knuth-none-eabi"
  },
  {
    "expected": "mmix-none-eabihf",
    "name": "testTripleFromString_mmix-none-eabihf",
    "result": "mmix-knuth-none-eabihf"
  },
  {
    "expected": "msp430-none-eabi",
    "name": "testTripleFromString_msp430-none-eabi",
    "result": "msp430-unknown-none-eabi"
  },
  {
    "expected": "msp430-none-eabihf",
    "name": "testTripleFromString_msp430-none-eabihf",
    "result": "msp430-unknown-none-eabihf"
  },
  {
    "expected": "or1k-none-eabi",
    "name": "testTripleFromString_or1k-none-eabi",
    "result": "or1k-unknown-none-eabi"
  },
  {
    "expected": "or1k-none-eabihf",
    "name": "testTripleFromString_or1k-none-eabihf",
    "result": "or1k-unknown-none-eabihf"
  },
  {
    "expected": "powerpc-none-eabi",
    "name": "testTripleFromString_powerpc-none-eabi",
    "result": "powerpc-unknown-none-eabi"
  },
  {
    "expected": "powerpc-none-eabihf",
    "name": "testTripleFromString_powerpc-none-eabihf",
    "result": "powerpc-unknown-none-eabihf"
  },
  {
    "expected": "powerpc64-none-eabi",
    "name": "testTripleFromString_powerpc64-none-eabi",
    "result": "powerpc64-unknown-none-eabi"
  },
  {
    "expected": "powerpc64-none-eabihf",
    "name": "testTripleFromString_powerpc64-none-eabihf",
    "result": "powerpc64-unknown-none-eabihf"
  },
  {
    "expected": "powerpc64le-none-eabi",
    "name": "testTripleFromString_powerpc64le-none-eabi",
    "result": "powerpc64le-unknown-none-eabi"
  },
  {
    "expected": "powerpc64le-none-eabihf",
    "name": "testTripleFromString_powerpc64le-none-eabihf",
    "result": "powerpc64le-unknown-none-eabihf"
  },
  {
    "expected": "powerpcle-none-eabi",
    "name": "testTripleFromString_powerpcle-none-eabi",
    "result": "powerpcle-unknown-none-eabi"
  },
  {
    "expected": "powerpcle-none-eabihf",
    "name": "testTripleFromString_powerpcle-none-eabihf",
    "result": "powerpcle-unknown-none-eabihf"
  },
  {
    "expected": "riscv32-none-eabi",
    "name": "testTripleFromString_riscv32-none-eabi",
    "result": "riscv32-unknown-none-eabi"
  },
  {
    "expected": "riscv32-none-eabihf",
    "name": "testTripleFromString_riscv32-none-eabihf",
    "result": "riscv32-unknown-none-eabihf"
  },
  {
    "expected": "riscv64-none-eabi",
    "name": "testTripleFromString_riscv64-none-eabi",
    "result": "riscv64-unknown-none-eabi"
  },
  {
    "expected": "riscv64-none-eabihf",
    "name": "testTripleFromString_riscv64-none-eabihf",
    "result": "riscv64-unknown-none-eabihf"
  },
  {
    "expected": "rx-none-eabi",
    "name": "testTripleFromString_rx-none-eabi",
    "result": "rx-unknown-none-eabi"
  },
  {
    "expected": "rx-none-eabihf",
    "name": "testTripleFromString_rx-none-eabihf",
    "result": "rx-unknown-none-eabihf"
  },
  {
    "expected": "s390-none-eabi",
    "name": "testTripleFromString_s390-none-eabi",
    "result": "s390-ibm-none-eabi"
  },
  {
    "expected": "s390-none-eabihf",
    "name": "testTripleFromString_s390-none-eabihf",
    "result": "s390-ibm-none-eabihf"
  },
  {
    "expected": "s390x-none-eabi",
    "name": "testTripleFromString_s390x-none-eabi",
    "result": "s390x-ibm-none-eabi"
  },
  {
    "expected": "s390x-none-eabihf",
    "name": "testTripleFromString_s390x-none-eabihf",
    "result": "s390x-ibm-none-eabihf"
  },
  {
    "expected": "sparc-none-eabi",
    "name": "testTripleFromString_sparc-none-eabi",
    "result": "sparc-unknown-none-eabi"
  },
  {
    "expected": "sparc-none-eabihf",
    "name": "testTripleFromString_sparc-none-eabihf",
    "result": "sparc-unknown-none-eabihf"
  },
  {
    "expected": "sparc64-none-eabi",
    "name": "testTripleFromString_sparc64-none-eabi",
    "result": "sparc64-unknown-none-eabi"
  },
  {
    "expected": "sparc64-none-eabihf",
    "name": "testTripleFromString_sparc64-none-eabihf",
    "result": "sparc64-unknown-none-eabihf"
  },
  {
    "expected": "wasm32-none-eabi",
    "name": "testTripleFromString_wasm32-none-eabi",
    "result": "wasm32-unknown-none-eabi"
  },
  {
    "expected": "wasm32-none-eabihf",
    "name": "testTripleFromString_wasm32-none-eabihf",
    "result": "wasm32-unknown-none-eabihf"
  },
  {
    "expected": "wasm64-none-eabi",
    "name": "testTripleFromString_wasm64-none-eabi",
    "result": "wasm64-unknown-none-eabi"
  },
  {
    "expected": "wasm64-none-eabihf",
    "name": "testTripleFromString_wasm64-none-eabihf",
    "result": "wasm64-unknown-none-eabihf"
  },
  {
    "expected": "x86_64-none-eabi",
    "name": "testTripleFromString_x86_64-none-eabi",
    "result": "x86_64-unknown-none-eabi"
  },
  {
    "expected": "x86_64-none-eabihf",
    "name": "testTripleFromString_x86_64-none-eabihf",
    "result": "x86_64-unknown-none-eabihf"
  }
]

[ghost]

I believe that 456619f3a645d9db49848cdf4242de12711cd86a solves this; would you mind checking to see if it works on all the cases that matter?

[GenericNerdyUsername]

whats happening now that #235230 is closed?