Fix 16 KB alignment of published Android libraries

.github/workflows/publish.yaml

@@ -22,8 +22,11 @@ jobs:
           echo "$SIGNING_KEY" | gpg --dearmor > ${HOME}/secring.gpg
 
       - name: Install Android NDK
-        # The NDK the Android Gradle plugin uses, which builds every Android native library
-        run: yes | "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" --install "ndk;28.2.13676358"
+        # Runners preset ANDROID_NDK_HOME to an older NDK, which KonanPlugin prefers over the Android
+        # Gradle plugin's; point it at NDK 28, whose linker aligns to 16 KB pages by default.
+        run: |
+          yes | "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" --install "ndk;28.2.13676358" > /dev/null
+          echo "ANDROID_NDK_HOME=$ANDROID_HOME/ndk/28.2.13676358" >> "$GITHUB_ENV"
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@v3
@@ -33,6 +36,11 @@ jobs:
         with:
           xcode-version: latest-stable
 
+      - name: Check 16 KB page alignment
+        run: |
+          ./gradlew --no-configuration-cache :soundfont:bundleAndroidMainAar
+          scripts/check-16kb-alignment.sh soundfont/build/outputs/aar/soundfont.aar
+
       - name: Publish To Maven Central
         env:
           ORG_GRADLE_PROJECT_mavenCentralUsername: ${{ secrets.MAVEN_CENTRAL_USERNAME }}

.github/workflows/test.yaml

@@ -23,6 +23,13 @@ jobs:
           distribution: 'zulu'
           java-version: '17'
 
+      - name: Install Android NDK
+        # Runners preset ANDROID_NDK_HOME to an older NDK, which KonanPlugin prefers over the Android
+        # Gradle plugin's; point it at NDK 28, whose linker aligns to 16 KB pages by default.
+        run: |
+          yes | "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" --install "ndk;28.2.13676358" > /dev/null
+          echo "ANDROID_NDK_HOME=$ANDROID_HOME/ndk/28.2.13676358" >> "$GITHUB_ENV"
+
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@v4
 
@@ -37,6 +44,11 @@ jobs:
       - name: Run tests
         run: ./gradlew :soundfont:linuxX64Test
 
+      - name: Check 16 KB page alignment
+        run: |
+          ./gradlew :soundfont:bundleAndroidMainAar
+          scripts/check-16kb-alignment.sh soundfont/build/outputs/aar/soundfont.aar
+
       - name: Upload test reports
         if: failure()
         uses: actions/upload-artifact@v4

scripts/check-16kb-alignment.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env sh
+# Fails unless every 64-bit native library in the given AAR has 16 KB aligned LOAD segments,
+# which Google Play requires for Android 15+ devices with 16 KB pages.
+# Usage: scripts/check-16kb-alignment.sh path/to/library.aar
+set -eu
+
+aar=$1
+readelf=$(ls "${ANDROID_NDK_HOME:?set ANDROID_NDK_HOME}"/toolchains/llvm/prebuilt/*/bin/llvm-readelf | head -1)
+work=$(mktemp -d)
+trap 'rm -rf "$work"' EXIT
+unzip -q "$aar" 'jni/*' -d "$work"
+
+status=0
+for so in "$work"/jni/arm64-v8a/*.so "$work"/jni/x86_64/*.so; do
+    [ -e "$so" ] || { echo "missing 64-bit libraries in $aar"; exit 1; }
+    for align in $("$readelf" -lW "$so" | awk '$1 == "LOAD" { print $NF }'); do
+        if [ $((align)) -lt 16384 ]; then
+            echo "FAIL ${so#"$work"/}: LOAD segment aligned to $align"
+            status=1
+        fi
+    done
+    [ $status -eq 0 ] && echo "ok   ${so#"$work"/}"
+done
+exit $status