Hello,

I try to update the ldc package on NixOS to 1.13.0 but get the following errors when running the wasm lit tests:

$ "/build/ldc-1.13.0-src/build/bin/ldc2" "-mtriple=wasm32-unknown-unknown-wasm" "-link-internally" "/build/ldc-1.13.0-src/tests/baremetal/wasm.d" "-conf=" "-I/build/ldc-1.13.0-src/tests/baremetal/inputs"
# command stderr:
ldc2: Unknown command line argument '-link-internally'.

and

$ "/build/ldc-1.13.0-src/build/bin/ldc2" "-mtriple=wasm32-unknown-unknown-wasm" "-betterC" "/build/ldc-1.13.0-src/tests/baremetal/wasm2.d"
# command stderr:
wasm2.o: file not recognized: File format not recognized
collect2: error: ld returned 1 exit status
Error: /nix/store/klci955kxil7q32ggran6lnhpnkk8yjz-gcc-wrapper-7.3.0/bin/gcc failed with status: 1

I thought that the missing -link-internally argument is caused by the -DLDC_WITH_LLD=OFF option but removing it doesn't solve the problem.
I think the main problem is that gcc is the build compiler in the environment and I haven't found a way to change that to clang.
Could this be the problem? It seems that LLD is not used for linking and that's also the reason why -link-internally isn't available.

The baremetal directory didn't change since 1.11.0 and 1.11.0 was working on NixOS with llvm 5.
The strange thing is that gcc was used for building with 1.11.0 too.
I build with llvm 6 now and wasm on NixOS seems to be enabled:

https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/compilers/llvm/6/llvm.nix#L15

Any ideas?

Thomas

First of all, these errors are not crucial.

Issue 1: tests/baremetal/wasm.d shouldn't explicitly use `-link-internally`, as that requires LDC to be built with CMake LDC_WITH_LLD != OFF *and* installed LLD dev files *and* that LLD to be patched (https://github.com/ldc-developers/lld) to work correctly.

Issue 2: both wasm.d and wasm2.d expect linking to WebAssembly to work, and that is currently only achievable via an integrated patched LLD. For this to work with an external linker (e.g., LLD's `wasm-ld`), LDC needs to be fixed by invoking the linker directly for WebAssembly targets, instead of issuing a gcc/clang command line as it currently does.

On Saturday, 22 December 2018 at 16:06:37 UTC, kinke wrote:
> First of all, these errors are not crucial.

Thank you for the detailed explanation.
I switched to llvm 5 and the errors are gone. Why is that?

On Saturday, 22 December 2018 at 16:24:01 UTC, Thomas Mader wrote:
> I switched to llvm 5 and the errors are gone. Why is that?

IIRC, WebAssembly support for LLD was added with LLD v6.