Add CI and build support for Android

.github/workflows/release.yml

@@ -65,6 +65,7 @@ jobs:
               {"target": "x86_64-windows-gnu-msvcrt-static", "runs-on": "ubuntu-latest"}
               {"target": "x86_64-windows-gnu-ucrt-shared", "runs-on": "ubuntu-latest"}
               {"target": "x86_64-windows-gnu-ucrt-static", "runs-on": "ubuntu-latest"}
+              {"target": "aarch64-android-static", "runs-on": "ubuntu-latest"}
               '
           )
           printf 'Matrix: %s\n' "$(jq <<< "$matrix")"
@@ -78,12 +79,26 @@ jobs:
       fail-fast: false
       matrix: ${{ fromJson(needs.prepare.outputs.matrix) }}
     runs-on: ${{ matrix.runs-on }}
+    env:
+      ANDROID_NDK_VERSION: 27.0.12077973
     steps:
       - name: Checkout
         uses: actions/checkout@v4
         with:
           ref: ${{ github.event.inputs.checkout-branch }}
           submodules: true
+      - name: Set up Java
+        if: contains(matrix.target, '-android-')
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 17
+      - name: Set up Android SDK
+        if: contains(matrix.target, '-android-')
+        uses: android-actions/setup-android@v3
+      - name: Install Android toolchain
+        if: contains(matrix.target, '-android-')
+        run: sdkmanager "platform-tools" "platforms;android-35" "ndk;${ANDROID_NDK_VERSION}" "cmake;3.22.1"
       - name: Build
         run: ./tools/build-release.sh "$BUILD_TARGETS"
         shell: bash

.github/workflows/rust-android-test.yml

@@ -0,0 +1,55 @@
+name: Rust - Android arm64 Link Test
+
+on: [workflow_dispatch]
+
+env:
+  CARGO_TERM_COLOR: always
+  ANDROID_NDK_VERSION: 27.0.12077973
+  ANDROID_PLATFORM: android-26
+  RUST_TARGET: aarch64-linux-android
+
+jobs:
+  build-and-link:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Set up Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 17
+
+      - name: Set up Android SDK
+        uses: android-actions/setup-android@v3
+
+      - name: Install Android toolchain
+        run: |
+          sdkmanager "platform-tools" "platforms;android-35" "ndk;${ANDROID_NDK_VERSION}" "cmake;3.22.1"
+
+      - name: Set up Rust target
+        run: rustup target add "${RUST_TARGET}"
+
+      - name: Build libmem static library for Android
+        run: |
+          cmake -S . -B build/android \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DCMAKE_TOOLCHAIN_FILE="$ANDROID_NDK_ROOT/build/cmake/android.toolchain.cmake" \
+            -DANDROID_ABI=arm64-v8a \
+            -DANDROID_PLATFORM="$ANDROID_PLATFORM" \
+            -DANDROID_STL=c++_shared \
+            -DLIBMEM_BUILD_STATIC=ON \
+            -DCMAKE_POSITION_INDEPENDENT_CODE=ON
+          cmake --build build/android --parallel
+
+      - name: Link Rust bindings for Android
+        env:
+          LIBMEM_DIR: ${{ github.workspace }}/build/android
+        working-directory: bindings/rust
+        run: |
+          export CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER="$ANDROID_NDK_ROOT/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android26-clang"
+          cargo test --no-run --target "${RUST_TARGET}" -p libmem --locked

bindings/rust/libmem-sys/build.rs

@@ -49,10 +49,18 @@ fn get_fetch_information() -> FetchInfo {
     };
 
     // Format archive prefix
-    let release_target = format!(
-        "libmem-{}-{}-{}-{}-{}",
-        version, target_arch, target_os, target_env, build_type
-    );
+    // NOTE: target_env can be empty (e.g. on Android), in which case it is omitted
+    let release_target = if target_env.is_empty() {
+        format!(
+            "libmem-{}-{}-{}-{}",
+            version, target_arch, target_os, build_type
+        )
+    } else {
+        format!(
+            "libmem-{}-{}-{}-{}-{}",
+            version, target_arch, target_os, target_env, build_type
+        )
+    };
 
     // Format archive URL
     let archive_ext = "tar.gz";
@@ -159,6 +167,10 @@ fn run_tests() {
             "libmem-1337-x86_64-windows-gnu-ucrt-static",
             ["1337", "windows", "x86_64", "gnu", "llvm"],
         ),
+        (
+            "libmem-1337-aarch64-android-static",
+            ["1337", "android", "aarch64", "", ""],
+        ),
     ]);
 
     for (expected, cargo_vars) in test_cases {
@@ -198,6 +210,8 @@ fn main() {
         vec!["user32", "psapi", "ntdll", "shell32"]
     } else if target_os == "linux" {
         vec!["dl", "m", "stdc++"]
+    } else if target_os == "android" {
+        vec!["dl", "m", "c++_shared"]
     } else if target_os == "freebsd" {
         vec!["dl", "kvm", "procstat", "elf", "m", "stdc++"]
     } else {

tools/build-release.sh

@@ -38,6 +38,13 @@ declare -gr WINDOWS_GNU_VARIANTS=(
   static
 )
 
+declare -gr ANDROID_PLATFORMS=(
+  aarch64-android
+)
+declare -gr ANDROID_VARIANTS=(
+  static
+)
+
 SCRIPT_DIR=$(dirname -- "$(realpath -m -- "$0")")
 declare -gr SCRIPT_DIR
 PROJECT_DIR=$(dirname -- "$SCRIPT_DIR")
@@ -62,6 +69,11 @@ function define_targets() {
       done
     fi
   done
+  for platform in "${ANDROID_PLATFORMS[@]}"; do
+    for variant in "${ANDROID_VARIANTS[@]}"; do
+      TARGETS+=("${platform}-${variant}")
+    done
+  done
   declare -gr TARGETS
 }
 
@@ -133,6 +145,7 @@ function main() {
   case "$target" in
   *-linux-*) _build_in_docker "$target" "$source_dir" "$out_dir" ;;
   *-windows-gnu-*) _build_in_docker "$target" "$source_dir" "$out_dir" ;;
+  *-android-*) _build_android "$target" "$source_dir" "$out_dir" ;;
   *) _build_locally "$target" "$source_dir" "$out_dir" ;;
   esac
 
@@ -200,6 +213,25 @@ function _build_locally() {
     bash <<<"set -Eeuo pipefail; shopt -s inherit_errexit; $(declare -f do_build); do_build; exit 0"
 }
 
+# Builds an Android target locally using the Android NDK's CMake toolchain.
+# Requires ANDROID_NDK_ROOT to point to an installed NDK (see ANDROID_NDK_VERSION
+# in .github/workflows/rust-android-test.yml for the version this is tested against).
+function _build_android() {
+  local target=$1 source_dir=$2 out_dir=$3
+
+  : "${ANDROID_NDK_ROOT:?ANDROID_NDK_ROOT must be set to an installed Android NDK path}"
+
+  init_temp_dir
+  _=_ \
+    _TARGET="$target" \
+    _SOURCE_DIR="$source_dir" \
+    _BUILD_DIR="${g_temp_dir}/build" \
+    _OUT_DIR="$out_dir" \
+    ANDROID_NDK_ROOT="$ANDROID_NDK_ROOT" \
+    ANDROID_PLATFORM="${ANDROID_PLATFORM:-android-26}" \
+    bash <<<"set -Eeuo pipefail; shopt -s inherit_errexit; $(declare -f do_build); do_build; exit 0"
+}
+
 # Perform the build and copy the results to the output directory.
 # This function must be self-contained and exportable.
 # Inputs:
@@ -253,6 +285,24 @@ function do_build() {
         variant_conf+=(-DCMAKE_C_FLAGS="$flags" -DCMAKE_CXX_FLAGS="$flags")
       fi
       ;;
+    *-android-*)
+      local android_abi
+      case "$_TARGET" in
+      aarch64-*) android_abi='arm64-v8a' ;;
+      *)
+        printf 'error: Unable to determine Android ABI from target: %s\n' "$_TARGET" >&2
+        return 1
+        ;;
+      esac
+      variant_conf+=(
+        -G 'Unix Makefiles'
+        -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK_ROOT:?ANDROID_NDK_ROOT required for android builds}/build/cmake/android.toolchain.cmake"
+        -DANDROID_ABI="$android_abi"
+        -DANDROID_PLATFORM="${ANDROID_PLATFORM:-android-26}"
+        -DANDROID_STL=c++_shared
+        -DCMAKE_POSITION_INDEPENDENT_CODE=ON
+      )
+      ;;
     *)
       local flags
       case "$_TARGET" in