feat: support Windows on Arm

Author: x1unix

.gitignore

@@ -1,3 +1,2 @@
 .vscode
 .idea
-

Dockerfile

@@ -1,11 +1,25 @@
 ARG GO_VERSION=1.20
+FROM golang:${GO_VERSION}-bookworm as builder
+ARG GO_VERSION
+ARG LLVM_MINGW64_VER=20240606
+ARG LLVM_MINGW64_SRC="https://github.com/mstorsjo/llvm-mingw/releases/download"
+ENV LLVM_MINGW64_VER="${LLVM_MINGW64_VER}"
+ENV LLVM_MINGW64_SRC="$LLVM_MINGW64_SRC"
+
+WORKDIR /tmp
+COPY --chmod=0755 scripts/setup-llvm-mingw64.sh /tmp/
+RUN /tmp/setup-llvm-mingw64.sh
+
+ARG GO_VERSION
 FROM golang:${GO_VERSION}-bookworm
 
 RUN apt update &&\
     apt install \
     make mingw-w64 bash --yes
-ADD docker-entrypoint.sh /usr/bin/docker-entrypoint.sh
-RUN chmod +x /usr/bin/docker-entrypoint.sh
+COPY --chmod=0755 scripts/docker-entrypoint.sh /usr/bin/docker-entrypoint.sh
+COPY --chmod=0755 scripts/install-llvm-mingw64.sh /tmp/install-llvm-mingw64.sh 
+COPY --from=builder /tmp/llvm-mingw64 /tmp/llvm-mingw64
+RUN /tmp/install-llvm-mingw64.sh /tmp/llvm-mingw64
 ENV PATH=/go/bin:$PATH \
     CGO_ENABLED=1 \
     GOOS=windows

Makefile

@@ -1,7 +1,8 @@
 IMG_NAME = x1unix/go-mingw-test
+DOCKER_OUT_TYPE=docker
 
 .PHONY: image
 image:
 	@if [ -z $(GO_VERSION) ]; then echo "usage: 'make image GO_VERSION=[GO VERSION NUMBER]'" && exit 1; fi; \
 	echo ":: Building image..." &&\
-	docker build -t $(IMG_NAME):$(GO_VERSION) -f Dockerfile . --build-arg GO_VERSION=$(GO_VERSION)
+	docker build --output=type=$(DOCKER_OUT_TYPE) -t $(IMG_NAME):$(GO_VERSION) -f Dockerfile . --build-arg GO_VERSION=$(GO_VERSION)

README.md

@@ -7,14 +7,16 @@ Docker image for building Go binaries for **Windows** with MinGW-w64 toolchain b
 
 Image provides simple cross-compilation environment for windows 32 and 64bit builds.
 
+**Supports Windows on Arm!**
+
 ## Supported Architectures
 
 Here is a list of supported host and target architectures:
 
 | Host Architecture   | Win x86 | Win x86-64 | Win Arm |
 | ------------------- | ------- | ---------- | ------- |
-| **arm64 / aarch64** | ✅      |  ✅        | 🚫      |
-| **amd64**           | ✅      |  ✅        | 🚫      |
+| **arm64 / aarch64** | ✅      |  ✅        | ✅      |
+| **amd64**           | ✅      |  ✅        | ✅      |
 
 ## Usage
 
@@ -39,7 +41,17 @@ docker run --rm -it -v /YourPackageSrc:/go/work \
 
 You will get compiled Windows binary.
 
-**For 32-bit toolchain**
+#### Windows On Arm
+
+Set `GOARCH=arm64` to build ARM Windows binary:
+
+```shell
+docker run --rm -it -e GOARCH=arm64 -v /YourPackageSrc:/go/work \
+    -w /go/work \
+    x1unix/go-mingw go build .
+```
+
+#### For 32-bit toolchain
 
 To build a 32-bit executable, set `GOARCH=386` variable:
 

docker-entrypoint.sh renamed to scripts/docker-entrypoint.sh

@@ -16,8 +16,14 @@ amd64)
     export CXX=i686-w64-mingw32-g++
     export CC=i686-w64-mingw32-gcc
     ;;
+arm64)
+    export CXX_FOR_TARGET=aarch64-w64-mingw32-g++
+    export CC_FOR_TARGET=aarch64-w64-mingw32-gcc
+    export CXX=aarch64-w64-mingw32-g++
+    export CC=aarch64-w64-mingw32-gcc
+    ;;
 *)
-    echo "Unsupported GOARCH variable value '$GOARCH'. Please set GOARCH environment variable to 'amd64' or '386'"
+    echo "Unsupported GOARCH variable value '$GOARCH'. Please set GOARCH environment variable to 'amd64', 'arm64' or '386'"
     exit 2
     ;;
 esac

scripts/install-llvm-mingw64.sh

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+set -e
+set -o pipefail
+
+trap 'echo "$0: Error on line $LINENO" >&2' ERR
+
+src="$1"
+if [ -z "$src" ]; then
+    echo "Error: missing source dir"
+    exit 1
+fi
+
+base_dir='/usr'
+
+echo ":: Installing llvm-mingw64..."
+echo "Source dir: $src"
+
+cd "$src" || exit 1
+find . -mindepth 1 -maxdepth 1 -type d ! -name . | while read -r subdir; do
+    dst_dir="$(basename "$subdir")"
+
+    case "$dst_dir" in
+    bin)
+        perm=755
+        ;;
+    *)
+        perm=644
+        ;;
+    esac
+
+    find "$subdir" -type f | while read -r file; do
+        dst="$base_dir/${file/.\//}"
+        mkdir -p "$(dirname "$dst")"
+        install -m $perm "$file" "$dst"
+    done
+done
+
+echo ":: Restoring symlinks..."
+while IFS= read -r line; do
+    src=$(echo "$line" | awk '{print $1}')
+    src="$base_dir/$src"
+
+    dest=$(echo "$line" | awk '{print $2}')
+    dest="$(realpath "$base_dir/$dest")"
+    ln -s "$dest" "$src"
+done <symlinks.txt
+
+echo ":: Cleanup"
+cd ..
+rm -rf "$src"

scripts/setup-llvm-mingw64.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+set -e
+set -o pipefail
+
+trap 'echo "$0: Error on line $LINENO" >&2' ERR
+
+if [ -z "$LLVM_MINGW64_SRC" ]; then
+    echo "Error: LLVM_MINGW64_SRC is undefined"
+    env
+    exit 1
+fi
+
+if [ -z "$LLVM_MINGW64_VER" ]; then
+    echo "Error: LLVM_MINGW64_VER is undefined"
+    env
+    exit 1
+fi
+
+apt update && apt install xz-utils --yes
+
+case "$(uname -m)" in
+aarch64 | arm64)
+    m_arch="aarch64"
+    ;;
+x86_64 | amd64)
+    m_arch="x86_64"
+    ;;
+*)
+    echo "Error: unsupported architecture $(uname -m)"
+    exit 1
+    ;;
+esac
+
+pkg_dir="llvm-mingw-$LLVM_MINGW64_VER-ucrt-ubuntu-20.04-$m_arch"
+pkg_file="$pkg_dir.tar.xz"
+src_url="$LLVM_MINGW64_SRC/$LLVM_MINGW64_VER/$pkg_file"
+echo ":: Downloading $src_url ..."
+wget "$src_url"
+# wget -q --spider "$src_url"
+
+if [ ! -f "$pkg_file" ]; then
+    echo "Error: can't find downloaded file $pkg_file"
+    ls -la
+    exit 1
+fi
+
+echo ":: Extracting file..."
+tar -xf "$pkg_file"
+rm "$pkg_file"
+
+echo ":: Preparing file list..."
+mv "$pkg_dir" llvm-mingw64
+cd llvm-mingw64
+
+# Keep llvm-mingw64 only for arm target to avoid conflict with gcc-mingw64
+rm bin/x86_64* bin/i686*
+rm -rf i686-w64-mingw32 x86_64-w64-mingw32
+
+# Backup symlinks
+find . -type l | while read -r symlink; do
+    src="${symlink/.\//}"
+    dst="$(dirname "$src")/$(readlink "$symlink")"
+    echo "$src $dst" >>symlinks.txt
+    rm "$symlink"
+done