使用Golang 1.10无法编译Windows DLL

Question

I'm having issues building a Windows DLL in Golang 1.10, which is supported in this latest version:

"The various build modes have been ported to more systems. Specifically, c-shared now works on linux/ppc64le, windows/386, and windows/amd64;" (Source: https://golang.org/doc/go1.10)

I have a very simple program right now (main.go) that only exports one function "Test", but am having issues when using the following "go build" command: env GOOS=windows GOARCH=386 go build -buildmode=c-shared main.go

Specifically, receiving the can't load package: package main: build constraints exclude all Go files in [PATH] error. The source code for main.go is shown below:

package main

import (
    "C"
    "fmt"
)

func main() {
    fmt.Println("from main")
}

//export Test
func Test() string {
    return "this is a test"
}

I've never encountered this error before and building without specifying GOOS and GOARCH works. Hoping someone has encountered this issue and can help me out.

Answer 1

1. Make sure you have MinGW installed on Ubuntu: sudo apt-get install gcc-mingw-w64-i686 and sudo apt-get install gcc-mingw-w64-x86-64

2. Compile using the following commands: env GOOS=windows GOARCH=386 CGO_ENABLED=1 CC=i686-w64-mingw32-gcc go build -buildmode=c-shared -o main.dll main.go and env GOOS=windows GOARCH=amd64 CGO_ENABLED=1 CC=x86_64-w64-mingw32-gcc go build -buildmode=c-shared -o main.dll main.go

3. Verify generated DLL works by testing the "Test" export: rundll32.exe main.dll,Test