Build ARM64 wheels for macOS (#296)

* Build ARM64 wheels for macOS

* Remove nproc

.github/workflows/ci.yml

@@ -86,6 +86,8 @@ jobs:
         include:
         - os: ubuntu-20.04
           arch: aarch64
+        - os: macos-11
+          arch: arm64
 
     steps:
       - uses: actions/checkout@v2
@@ -111,6 +113,7 @@ jobs:
           CIBW_TEST_REQUIRES: pytest
           CIBW_ARCHS: ${{ matrix.arch }}
           CIBW_SKIP: pp* *-musllinux_*
+          CIBW_TEST_SKIP: "*-macosx_arm64"
 
       - name: Upload Python wheels
         uses: actions/upload-artifact@v2

bindings/python/tools/prepare_build_environment.sh

@@ -4,15 +4,36 @@ set -e
 set -x
 
 ROOT_DIR=$PWD
-ICU_VERSION=${ICU_VERSION:-70.1}
-ICU_ROOT=$ROOT_DIR/icu-$ICU_VERSION
-
-# Install ICU.
-curl -L -O https://github.com/unicode-org/icu/releases/download/release-${ICU_VERSION/./-}/icu4c-${ICU_VERSION/./_}-src.tgz
-tar xf icu4c-*-src.tgz
-cd icu/source
-CFLAGS="-O3 -fPIC" CXXFLAGS="-O3 -fPIC" ./configure --disable-shared --enable-static --prefix=$ICU_ROOT
-make -j2 install
+ICU_ROOT=$ROOT_DIR/icu
+CMAKE_EXTRA_ARGS=""
+
+if [ "$CIBW_ARCHS" == "arm64" ]; then
+
+    # Download ICU ARM64 binaries from Homebrew.
+    brew fetch --force --bottle-tag=arm64_big_sur icu4c \
+        | grep "Downloaded to" \
+        | awk '{ print $3 }' \
+        | xargs -I{} tar xf {} -C $ROOT_DIR
+
+    mv icu4c/*.* $ICU_ROOT
+
+    # Remove dynamic libraries to force static link.
+    rm $ICU_ROOT/lib/*.dylib
+
+    CMAKE_EXTRA_ARGS="-DCMAKE_OSX_ARCHITECTURES=arm64"
+
+else
+
+    # Download and compile ICU from sources.
+    ICU_VERSION=${ICU_VERSION:-70.1}
+    curl -L -O https://github.com/unicode-org/icu/releases/download/release-${ICU_VERSION/./-}/icu4c-${ICU_VERSION/./_}-src.tgz
+    tar xf icu4c-*-src.tgz
+    cd icu/source
+    CFLAGS="-O3 -fPIC" CXXFLAGS="-O3 -fPIC" ./configure --disable-shared --enable-static --prefix=$ICU_ROOT
+    make -j2 install
+
+fi
+
 cd $ROOT_DIR
 
 # Install cmake.
@@ -22,6 +43,6 @@ pip install "cmake==3.18.*"
 rm -rf build
 mkdir build
 cd build
-cmake -DLIB_ONLY=ON -DICU_ROOT=$ICU_ROOT ..
-make -j2 install
+cmake -DLIB_ONLY=ON -DICU_ROOT=$ICU_ROOT $CMAKE_EXTRA_ARGS ..
+VERBOSE=1 make -j2 install
 cd $ROOT_DIR