cmd/link: -buildmode=c-shared not supported on windows/arm

[TopperDEL]

What version of Go are you using (go version)?

$ go version 1.15.6

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/vsts/.cache/go-build"
GOENV="/home/vsts/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/vsts/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/vsts/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/opt/hostedtoolcache/go/1.15.6/x64"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/opt/hostedtoolcache/go/1.15.6/x64/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build442356246=/tmp/go-build -gno-record-gcc-switches"

What did you do?

I try to cross-compile a Go-library for windows/arm and windows/arm64 to P/Invoke it from .Net. Although Go states to support "windows/arm" as a build target this is not true for buildmode=c-shared.

What did you expect to see?

windows/arm being supported.

What did you see instead?

"-buildmode c-shared not supported for windows/arm"

[bcmills]

CC @zx2c4

[TopperDEL]

Is there anything I could do? Might it already work just by adjusting the parameter check and let that combination "go through"?

If not: is there any ETA for this? I do not want to make pressure - it's just quite necessary for an app I'm currently building and it would at least be helpful to get a feeling about the complexity, if it should be possible or not and when it might be realistic that the feature will make it into Go.

This would bring Go to devices like the HoloLens 2 or a Surface X. I can't imagine that I'm the only one needing this. :)

Thank you!

[thanm]

I'm not aware of any specific issues blocking "-buildmode=c-shared" on windows/arm, maybe @cherrymui knows more. I think the main stumbling block is that we haven't had an owner for the port, nor have we a builder. You could certainly try commenting out the guard in the linker and see how things go.

[bcmills]

I think the main stumbling block is that we haven't had an owner for the port, nor have we a builder.

We do have a builder now, at least! (A “reverse” builder run by @zx2c4.)
https://github.com/golang/build/blob/6f0aa4e1ac923ee1f8249641d38ecb96db02a1e8/dashboard/builders.go#L2250-L2256

[thanm]

Ah, thanks.

[TopperDEL]

I'm not that deep into Go and how builders work and help here - what needs to happen then to bring this further?
Thank you all for your help and quick response!

[TopperDEL]

Sorry if I push here - what needs to be done to get further? There seems to be a builder available. Can someone bringt this topic further?

Thank you in advance!

[cherrymui]

windows/arm port doesn't support cgo yet. I think we need to support cgo before adding support of c-shared build mode. Thanks.

[TopperDEL]

Thanks @cherrymui for the reply. I'm sorry for asking again and again but what/who could do this? I need windows/arm64 with cgo very soon so if there is anything someone could do to bring this further, I would be very happy and thankful. :)

[gopherbot]

Change https://golang.org/cl/291630 mentions this issue: cmd/link: set SizeOfRawData filed in COFF files for .bss section

[gopherbot]

Change https://golang.org/cl/291630 mentions this issue: cmd/link: set SizeOfRawData field in COFF files for .bss section

[gopherbot]

Change https://golang.org/cl/291632 mentions this issue: cmd/link: do not pass -Bsymbolic for PE DLLs

[gopherbot]

Change https://golang.org/cl/291633 mentions this issue: cmd/link: set .ctors COFF section to writable and aligned to 8 bytes

[gopherbot]

Change https://golang.org/cl/291633 mentions this issue: cmd/link: set .ctors COFF section to writable and aligned

[gopherbot]

Change https://golang.org/cl/291635 mentions this issue: runtime/cgo: implement for windows/arm and windows/arm64

[TopperDEL]

Can someone provide me with an update on this issue? I do not understand all the implications here and where to get the status. But I need this to be fixed/enhanced so I appreciate every feedback I get. Thank you very much!

[TopperDEL]

Any news on this one? :)

[TopperDEL]

According to the release notes of Go 1.17 beta1, this should work now - am I right?
https://tip.golang.org/doc/go1.17#ports

"Go 1.17 adds support of 64-bit ARM architecture on Windows (the windows/arm64 port). This port supports cgo."

But if It try this:

export CC="arm-none-eabi-gcc"     
export CXX="arm-none-eabi-g++"     
export GOOS="windows"     
export GOARCH="arm64"     
export GOARM=7     
export CGO_ENABLED="1"     
/home/vsts/go/bin/go1.17beta1 build -ldflags="-s -w" -o storj_uplink.dll -buildmode c-shared

I get this:
-buildmode=c-shared not supported on windows/arm64

Is there still something missing?

[zx2c4]

This github issue is for windows/arm, not for windows/arm64, and is therefore not related to the contents of your message.

What you're looking for is https://go-review.googlesource.com/c/go/+/326310/ which is a work in progress.

[zx2c4]

@rsc - do you intend to work on windows/arm cgo support for 1.18? If so, great. If not, could you let me know so I can potentially allocate resources to it?

[TopperDEL]

This github issue is for windows/arm, not for windows/arm64, and is therefore not related to the contents of your message.

What you're looking for is https://go-review.googlesource.com/c/go/+/326310/ which is a work in progress.

Ah, missed that - thank you.