target "triples"

[alex-s168]

for LM, we want to support different combinations of:

• compiler backend
• target architecture
• target environment: libc, wasip1, ...
• target OS (optional-ish)
• object format

to do that, we should add this target "triple" format:

format

<backend> - <arch> - <environment> - <object format> - ....

everything after the fourth dash (if present) can be ignored.
this is for forwards compatibility.

valid backend values

• c
• c_gnu: also for clang
• c_clang
• c_msvc
• c_tcc

valid architectures + sub architectures:

• c: should be used when architecture is completely abstracted away by C backend
• all LLVM architectures (see here). syntax for arch+sub arch should be: arch_subarch

valid environment values:

• freestanding
• libc
• libc_unix
• libc_posix
• libc_glibc
• libc_win32
• wasip1
• wasip1_threads
• ...

valid object format values:

• external: when abstracted away by external toolchain (when used with for example C backend)
• elf
• wasm: wasm binary format
• coff
• ...

examples:

• c-c-libc-external: what we are doing currently
• c_clang-riscv64-libc_posix-external
• llvm-wasm32-wasip1_threads-wasm : there will probably never be an LLVM backend, but that is just an example.

[alex-s168]

@andrew-johnson-4 thoughts?

[andrew-johnson-4]

yeah, triples are the best practice way of doing this. I just don't want to think about this until core is more stable.