add Linux/ARM64 cross-compilation support

.github/workflows/main.yml

@@ -168,6 +168,22 @@ jobs:
 
  - name: Run docker_build script
  run: ./docker_build.sh
+
+ - name: Cross-compile for ARM64
+ # Hacktastic cross-compilation step: build and install an ARM64 LLVM,
+ # reusing everything else we built using the native toolchain. Once
+ # GitHub provides ARM64 runners to open source projects (planned for
+ # second half of 2024) we'll be able to build natively and avoid this
+ # step.
+ run: |
+ docker run --rm \
+ --user $(id -u):$(id -g) \
+ -v "$PWD":/workspace:Z \
+ -v ~/.ccache:/home/builder/.ccache:Z \
+ --tmpfs /tmp:exec \
+ wasi-sdk-builder:latest \
+ bash cross_build_arm64.sh
+
  - name: Upload artifacts
  uses: actions/upload-artifact@v4
  with:

Dockerfile

@@ -18,6 +18,8 @@ RUN apt-get update \
  python3 \
  git \
  ninja-build \
+ gcc-aarch64-linux-gnu \
+ g++-aarch64-linux-gnu \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/*
 
@@ -31,7 +33,8 @@ ENV PATH /opt/cmake/bin:$PATH
 ENV RUSTUP_HOME=/rust/rustup CARGO_HOME=/rust/cargo PATH=$PATH:/rust/cargo/bin
 RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | \
  sh -s -- -y --profile=minimal && \
- chmod -R a+w /rust
+ chmod -R a+w /rust && \
+ rustup target add aarch64-unknown-linux-gnu
 
 RUN groupadd -g ${GID} builder && \
  useradd --create-home --uid ${UID} --gid ${GID} builder

Makefile

@@ -283,8 +283,8 @@ package: build/package.BUILT
 
 build/package.BUILT: build strip
  mkdir -p dist
- ./deb_from_installation.sh $(shell pwd)/dist "$(VERSION)" "$(BUILD_PREFIX)"
- ./tar_from_installation.sh "$(shell pwd)/dist" "$(VERSION)" "$(BUILD_PREFIX)"
+ ./deb_from_installation.sh $(shell pwd)/dist "$(VERSION)" "$(BUILD_PREFIX)" "$(DEB_ARCH)"
+ ./tar_from_installation.sh "$(shell pwd)/dist" "$(VERSION)" "$(BUILD_PREFIX)" "$(TAR_MACHINE)"
  touch build/package.BUILT
 
 .PHONY: default clean build strip package check

cross_build_arm64.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+set -ex
+
+rm -r build/llvm build/llvm.BUILT
+NINJA_FLAGS=-v make strip LLVM_CMAKE_FLAGS="-DLLVM_CCACHE_BUILD=ON -DCMAKE_C_COMPILER=aarch64-linux-gnu-gcc -DCMAKE_CXX_COMPILER=aarch64-linux-gnu-g++ -DCMAKE_CROSSCOMPILING=True -DCMAKE_CXX_FLAGS=-march=armv8-a -DCMAKE_SYSTEM_PROCESSOR=arm64 -DCMAKE_SYSTEM_NAME=Linux -DLLVM_HOST_TRIPLE=aarch64-linux-gnu"
+CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER=aarch64-linux-gnu-gcc cargo install [email protected] --root "$(pwd)/build/install/opt/wasi-sdk" --target aarch64-unknown-linux-gnu
+mkdir -p dist
+./deb_from_installation.sh "$(pwd)/dist" "$(./version.py)" "$(pwd)/build/install/opt/wasi-sdk" "arm64"
+./tar_from_installation.sh "$(pwd)/dist" "$(./version.py)" "$(pwd)/build/install/opt/wasi-sdk" "linux-arm64"

deb_from_installation.sh

@@ -27,13 +27,17 @@ else
  INSTALL_DIR=/opt/wasi-sdk
 fi
 
+if [ -n "$4" ]; then
+ ARCH="$4"
+else
+ ARCH=$(dpkg --print-architecture)
+fi
+
 if [ ! -d $INSTALL_DIR ] ; then
  echo "Directory $INSTALL_DIR doesn't exist. Nothing to copy from."
  exit 1
 fi
 
-ARCH=$(dpkg --print-architecture)
-
 rm -rf build/pkg
 mkdir -p build/pkg/opt
 mkdir -p build/pkg/DEBIAN

docker/Dockerfile

@@ -8,7 +8,7 @@
 # separately.
 FROM ubuntu:22.04 as dist
 
-ADD dist/wasi-sdk-*.*-linux.tar.gz /
+ADD dist/wasi-sdk-*.*-linux-amd64.tar.gz /
 ADD dist/libclang_rt.builtins-wasm32-wasi-*.*.tar.gz /wasi-sysroot-clang_rt
 
 # Move versioned folder to unversioned to using bash glob to allow

tar_from_installation.sh

@@ -19,14 +19,19 @@ else
  INSTALL_DIR=/opt/wasi-sdk
 fi
 
-case "$(uname -s)" in
- Linux*) MACHINE=linux;;
- Darwin*) MACHINE=macos;;
- CYGWIN*) MACHINE=cygwin;;
- MINGW*) MACHINE=mingw;;
- MSYS*) MACHINE=msys;; #MSYS_NT-10.0-19043
- *) MACHINE="UNKNOWN"
-esac
+if [ -n "$4" ]; then
+ MACHINE="$4"
+else
+ case "$(uname -s):$(uname -m)" in
+ Linux*:aarch64) MACHINE=linux-arm64;;
+ Linux*:x86_64) MACHINE=linux-amd64;;
+ Darwin*) MACHINE=macos;;
+ CYGWIN*) MACHINE=cygwin;;
+ MINGW*) MACHINE=mingw;;
+ MSYS*) MACHINE=msys;; #MSYS_NT-10.0-19043
+ *) MACHINE="UNKNOWN"
+ esac 
+fi
 
 if [ ! -d $INSTALL_DIR ] ; then
  echo "Directory $INSTALL_DIR doesn't exist. Nothing to copy from."