Fix Android native build

.github/workflows/main.yml

@@ -28,3 +28,27 @@ jobs:
       uses: gradle/actions/setup-gradle@v4.2.1
     - name: Test with Gradle
       run: ./gradlew test --stacktrace
+
+  android-native:
+    name: Build Android native library
+    runs-on: ubuntu-22.04
+    env:
+      ORG_GRADLE_PROJECT_ossrhUsername: na
+      ORG_GRADLE_PROJECT_ossrhPassword: na
+      ANDROID_NDK_VERSION: "27.1.12297006"
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up JDK 17
+      uses: actions/setup-java@v4
+      with:
+        java-version: '17'
+        distribution: 'corretto'
+    - name: Setup Gradle
+      uses: gradle/actions/setup-gradle@v4.2.1
+    - name: Set up Android SDK
+      uses: android-actions/setup-android@v3
+    - name: Install Android NDK
+      run: |
+        "${ANDROID_HOME}/cmdline-tools/latest/bin/sdkmanager" "ndk;${ANDROID_NDK_VERSION}"
+    - name: Build Android native library
+      run: ./gradlew :tree-sitter:buildNative -PtreeSitterTargets=aarch64-linux-android --stacktrace

buildSrc/src/main/groovy/BuildNativeTask.groovy

@@ -13,6 +13,7 @@ import org.gradle.api.tasks.Internal
 import org.gradle.api.tasks.OutputFiles
 import org.gradle.api.tasks.TaskAction
 import org.treesitter.build.Utils
+import java.util.Locale
 
 class BuildNativeTask extends DefaultTask{
 
@@ -160,18 +161,19 @@ class BuildNativeTask extends DefaultTask{
             def jniMdIncludeDir = getJniMdInclude(target)
             def jniOutFile = Utils.jniOutFile(project, target, libName)
 
-            def cmd = [
-                    zigExe, "c++",
+            def cmd = []
+            cmd.addAll(this.compilerArgsForTarget(target))
+            cmd.addAll([
                     "-g0",
                     "-fno-sanitize=undefined",
+                    "-fPIC",
                     "-shared",
-                    "-target", target,
                     "-I", srcDir,
                     "-I", srcDir.dir("lib/include"),
                     "-I", jniIncludeDir,
                     "-I", jniMdIncludeDir,
                     "-o", jniOutFile
-            ]
+            ])
             additionalIncludeDirs.forEach { f ->
                 cmd.add("-I")
                 cmd.add(f)
@@ -187,6 +189,44 @@ class BuildNativeTask extends DefaultTask{
         this.removeWindowsDebugFiles()
     }
 
+    List<Object> compilerArgsForTarget(String target) {
+        if (!target.contains("android")) {
+            return [zigExe, "c++", "-target", target]
+        }
+
+        def ndkDir = findAndroidNdkDir()
+        def hostTag = System.getProperty("os.name").toLowerCase(Locale.ROOT).contains("mac")
+                ? "darwin-x86_64"
+                : "linux-x86_64"
+        def apiLevel = project.findProperty("androidApiLevel") ?: "21"
+        def compiler = new File(
+                ndkDir,
+                "toolchains/llvm/prebuilt/${hostTag}/bin/aarch64-linux-android${apiLevel}-clang"
+        )
+        if (!compiler.exists()) {
+            throw new GradleException("Android compiler not found: ${compiler}. Set ANDROID_NDK_HOME or ANDROID_NDK_ROOT.")
+        }
+        return [compiler]
+    }
+
+    File findAndroidNdkDir() {
+        def envNdk = System.getenv("ANDROID_NDK_HOME") ?: System.getenv("ANDROID_NDK_ROOT")
+        if (envNdk) {
+            return new File(envNdk)
+        }
+
+        def sdkDir = System.getenv("ANDROID_HOME") ?: System.getenv("ANDROID_SDK_ROOT")
+        if (sdkDir) {
+            def ndkRoot = new File(sdkDir, "ndk")
+            def ndks = ndkRoot.listFiles()?.findAll { it.isDirectory() }?.sort { a, b -> b.name <=> a.name }
+            if (ndks) {
+                return ndks.first()
+            }
+        }
+
+        throw new GradleException("Android NDK not found. Set ANDROID_NDK_HOME, ANDROID_NDK_ROOT, ANDROID_HOME, or ANDROID_SDK_ROOT.")
+    }
+
     private void removeWindowsDebugFiles(){
         def files = jniOutDir.asFileTree.matching {
             include("**/*.pdb")