Build error on Windows (arm64)

[targos]

https://ci.nodejs.org/job/node-compile-windows/46957/nodes=win-vs2019-arm64/console

11:13:20   simd.cc
11:13:21 C:\workspace\node-compile-windows\node\deps\v8\src\objects\simd.cc(99,28): error C2078: too many initializers [C:\workspace\node-compile-windows\node\tools\v8_gypfiles\v8_base_without_compiler.vcxproj]
11:13:21 C:\workspace\node-compile-windows\node\deps\v8\src\objects\simd.cc(109,1): error C2766: explicit specialization; 'int v8::internal::`anonymous-namespace'::extract_first_nonzero_index<uint32x4_t>(uint32x4_t)' has already been defined [C:\workspace\node-compile-windows\node\tools\v8_gypfiles\v8_base_without_compiler.vcxproj]

[targos]

The first error is considered "not a bug" by Microsoft. What should we do?

@nodejs/platform-windows-arm

https://developercommunity.visualstudio.com/t/error-c2078-too-many-initializers-when-using-arm-n/402911

[pbo-linaro]

It seems like a workaround was given by Microsoft (using .128_u8).
It it's working, would that be possible to simply add an ifdef for that compiler (vs gcc/clang)?

[niyas-sait]

We probably should upstream a patch to V8 as well to fix the same issue with MSVC.

[targos]

Yes, please send a patch upstream if possible!

[pbo-linaro]

I'll look at it :)
If we integrate that in v8, can you easily update to latest version (including current trunk)?

[targos]

Yes, the canary branch in this repository is updated automatically every day.

[pbo-linaro]

@targos After investigation, it is indeed not a bug in msvc, but simply the C++ standard dictating this (and gcc having an extension that accepts it). The way to initialize those variables must be changed specifically for msvc.

In more, there is another problem appearing with a conflict between two template specialization.

Quick and dirty details and patch are available here: https://github.com/pbo-linaro/node/commit/7586c64749459e238023834dc0ab8b0d941c819b.

I'll try to upstream that in V8 directly (so nodejs and other projects can benefit from it).
If that's not ready for next nodejs release, you can still use that patch 👍

[pbo-linaro]

@targos I just submitted 4 patches to fix all compilation errors of V8 with MSVC (including some not concerning Node).

This one solves issue discussed here.

[targos]

Amazing!

[pbo-linaro]

@targos Patches are now merged upstream, v8 canary should be able to compile for windows from now.

Don't hesitate to ping me if you need help in the future 👍

[targos]

Cherry-picked all patches to nodejs/node#44741.