riscv64imac-unknown-nuttx-elf warns about abi/instruction-set mismatch

[saethlin]

When using -Zbuild-std=core --target=riscv64imac-unknown-nuttx-elf I see

Hard-float 'd' ABI can't be used for a target that doesn't support the D instruction set extension (ignoring target-abi)

which seems like an indicator that something is broken.

I think LLVM is seeing a mismatch between

rust/compiler/rustc_target/src/spec/targets/riscv64imac_unknown_nuttx_elf.rs

Line 24 in 9649706

llvm_abiname: "lp64d".into(),

and the lack of a +d in

rust/compiler/rustc_target/src/spec/targets/riscv64imac_unknown_nuttx_elf.rs

Line 27 in 9649706

features: "+m,+a,+c".into(),

But of course I don't know this target, or whether this is somehow a bug in LLVM.

cc @no1wudi

[no1wudi]

@saethlin Thanks for your report, I'll submit a fix soon, the support (include libstd/libc) for NuttX is in early stage, there are still many issues at present, sorry for that

[saethlin]

No need to apologize, just saying something because I saw something :)