[xgo] The first phase of hacking xgo

 xgo is a great Go CGO cross compiler that can help users to build the application written in Golang to multi-platforms at the same time. 

For more information in details, please check out these URLs:

https://github.com/karalabe/xgo
https://www.jianshu.com/p/a6047d3f976e

But, without any further study, we probably cannot understand how it works well. So here I just give some information about it. I will use my Github repository as the example:

# Install xgo

$ go get github.com/karalabe/xgo

$ git clone https://github.com/teyenliu/win-shared-example

$ cd win-shared-example

# Use xgo to cross-compile to windows/amd64

$ xgo -targets windows/amd64 github.com/teyenliu/win-shared-example

Then, we finish the cross-compilation for my application
And actually, xgo, this tool, is based on its prebuilt docker image: "karalabe/xgo-latest" to complete the cross-compilation task. We can check the dockerhub for it as well: https://hub.docker.com/r/karalabe/xgo-latest/builds

So, we can directly run this Docker Image to cross-compile my application based on my case as follows:

$ docker run --rm -v /home/liudanny/git/xgo:/build \

-v /home/liudanny/.xgo-cache:/deps-cache:ro \

-e REPO_REMOTE= \

-e REPO_BRANCH= \

-e PACK= \

-e DEPS= \

-e ARGS= \

-e OUT= \

-e FLAG_V=false \

-e FLAG_X=false \

-e FLAG_RACE=false \

-e FLAG_TAGS= \

-e FLAG_LDFLAGS= \

-e FLAG_BUILDMODE=default \

-e TARGETS=windows/amd64 \

-e EXT_GOPATH= \

karalabe/xgo-latest \

github.com/teyenliu/win-shared-example

Furthermore, we can directly run xgo's build.sh to cross-compile my application in the host instead of in in the container:

$ sudo su

# set Golang path

export PATH=$PATH:/usr/local/go/bin

export GOPATH=$HOME/go

export PATH=$PATH:$GOPATH/bin

# rm /deps in advance

rm -rf /deps

# run build.sh

env GO111MODULE=off \

env REPO_REMOTE= \

env REPO_BRANCH= \

env PACK= \

env DEPS= \

env ARGS= \

env OUT= \

env FLAG_V=false \

env FLAG_X=false \

env FLAG_RACE=false \

env FLAG_TAGS= \

env FLAG_LDFLAGS= \

env FLAG_BUILDMODE=default \

env TARGETS=windows/amd64 \

env EXT_GOPATH= \

env BUILD_DEPS=/home/liudanny/git/xgo/docker/base/build_deps.sh \

env BOOTSTRAP_REPO=/home/liudanny/git/xgo/docker/base/bootstrap_repo.sh \

env BOOTSTRAP_PURE=/home/liudanny/git/xgo/docker/base/bootstrap_pure.sh \

env BOOTSTRAP=/home/liudanny/git/xgo/docker/base/bootstrap.sh \

env PATH=/usr/local/go/bin:$PATH \

./build.sh github.com/teyenliu/win-shared-example

Reference:
Golang 交叉编译
Golang交叉编译各个平台的二进制文件
Fyne Cross Compile

The following commands are not succesful to work for cross-compilation

$ CGO_ENABLED=1 CXX="x86_64-w64-mingw32-g++" CXX_FOR_TARGET="x86_64-w64-mingw32-g++" CC="x86_64-w64-mingw32-gcc" CC_FOR_TARGET="x86_64-w64-mingw32-gcc" GOOS=windows GOARCH=amd64 \

go build -ldflags -v -x -installsuffix cgo -o example.exe main.go

$ GOOS=windows GOARCH=amd64 CGO_ENABLED=1 CC=x86_64-w64-mingw32-gcc go build -ldflags -v -x -installsuffix cgo -o example.exe main.go