Optimize Android APK: always build Release, drop x86, enable IL stripping + compression

.github/workflows/release.yml

@@ -48,7 +48,9 @@ jobs:
           NDK_HOME="$ANDROID_HOME/ndk/29.0.14206865"
           CMAKE_BIN="$ANDROID_HOME/cmake/3.22.1/bin/cmake"
 
-          for ABI in arm64-v8a armeabi-v7a x86; do
+          # Only build arm64 and arm32.  x86 removed to reduce APK size —
+          # modern emulators use x86_64 or ARM translation.
+          for ABI in arm64-v8a armeabi-v7a; do
             echo "::group::Building osu_native for $ABI"
             "$CMAKE_BIN" -B "build-native/$ABI" -S osu.Android/Native \
               -DCMAKE_TOOLCHAIN_FILE="$NDK_HOME/build/cmake/android.toolchain.cmake" \
@@ -86,6 +88,9 @@ jobs:
             echo "version=0.0.0" >> "$GITHUB_OUTPUT"
           fi
 
+      # Always build Release for full optimization (trimming, AOT, compression).
+      # When a keystore is available we sign with it; otherwise the SDK produces
+      # a debug-signed Release APK that can be sideloaded for testing.
       - name: Build Android APK (signed)
         if: steps.keystore.outputs.has_keystore == 'true'
         env:
@@ -105,10 +110,10 @@ jobs:
           -p:AndroidSigningKeyPass="$ANDROID_KEY_PASS"
           -p:AndroidSigningStorePass="$ANDROID_STORE_PASS"
 
-      - name: Build Android APK (unsigned)
+      - name: Build Android APK (unsigned Release)
         if: steps.keystore.outputs.has_keystore != 'true'
         run: >
-          dotnet publish -c Debug
+          dotnet publish -c Release
           osu.Android/osu.Android.csproj
           -f net10.0-android
           -p:Version="${{ steps.version.outputs.version }}"
@@ -118,16 +123,29 @@ jobs:
       - name: Find APK
         id: find_apk
         run: |
+          # Both paths build Release.  Signed builds produce *-Signed.apk; unsigned
+          # builds produce the base APK name.  Search publish dir first, then fallback.
           if [ "${{ steps.keystore.outputs.has_keystore }}" == "true" ]; then
-            CONFIG="Release"
+            APK=$(find "osu.Android/bin/Release/net10.0-android/publish" -maxdepth 1 -name "*-Signed.apk" 2>/dev/null | head -1)
+            if [ -z "$APK" ]; then
+              APK=$(find "osu.Android/bin/Release" -name "*-Signed.apk" | head -1)
+            fi
           else
-            CONFIG="Debug"
+            APK=$(find "osu.Android/bin/Release/net10.0-android/publish" -maxdepth 1 -name "*.apk" 2>/dev/null | head -1)
+            if [ -z "$APK" ]; then
+              APK=$(find "osu.Android/bin/Release" -name "*.apk" | head -1)
+            fi
           fi
-          PUBLISH_DIR="osu.Android/bin/$CONFIG/net10.0-android/publish"
-          APK=$(find "$PUBLISH_DIR" -maxdepth 1 -name "*.apk" 2>/dev/null | head -1)
+
           if [ -z "$APK" ]; then
-            APK=$(find "osu.Android/bin/$CONFIG" -name "*.apk" | head -1)
+            echo "::error::Failed to locate APK. Listing bin directory:"
+            find osu.Android/bin -name "*.apk" -o -name "*.aab" 2>/dev/null || true
+            exit 1
           fi
+
+          APK_SIZE=$(stat -c %s "$APK" 2>/dev/null || stat -f %z "$APK" 2>/dev/null || wc -c < "$APK")
+          APK_SIZE_MB=$((APK_SIZE / 1048576))
+          echo "Found APK: $APK ($APK_SIZE_MB MB)"
           echo "apk_path=$APK" >> "$GITHUB_OUTPUT"
 
       - name: Upload APK artifact

osu.Android.props

@@ -1,17 +1,36 @@
 <Project>
   <PropertyGroup>
     <SupportedOSPlatformVersion>33.0</SupportedOSPlatformVersion>
-    <RuntimeIdentifiers>android-x86;android-arm;android-arm64</RuntimeIdentifiers>
+    <!-- arm64-v8a covers 99%+ of modern Android devices.
+         armeabi-v7a is kept for older 32-bit devices.
+         x86 removed — only used by legacy emulators; modern x86_64 emulators
+         run arm64 binaries via native translation (no dedicated x86 build needed). -->
+    <RuntimeIdentifiers>android-arm;android-arm64</RuntimeIdentifiers>
     <AndroidPackageFormat>apk</AndroidPackageFormat>
+    <!-- CJK and Mideast encodings are needed for song metadata display.
+         Rare covers supplementary Unicode blocks. West is the default Latin set. -->
     <MandroidI18n>CJK;Mideast;Rare;West;Other;</MandroidI18n>
     <AndroidHttpClientHandlerType>Xamarin.Android.Net.AndroidMessageHandler</AndroidHttpClientHandlerType>
     <!-- NullabilityInfoContextSupport is disabled by default for Android -->
     <NullabilityInfoContextSupport>true</NullabilityInfoContextSupport>
     <EmbedAssembliesIntoApk>true</EmbedAssembliesIntoApk>
-    <!-- Suppress XA0141 page-size warnings during build. The actual .so files are patched
-         to 16 KB alignment by build/PatchElfPageSize.targets, but the SDK check runs before
-         the patch in some build orderings. This suppression is harmless since we do fix them. -->
+    <!-- Suppress XA0141 page-size warnings. ELF patching is disabled for all configurations
+         (see PatchElfPageSizeEnabled below) to prevent APK signature corruption.
+         The XA0141 warning is therefore expected and harmless.
+         AndroidPageSize16KBCompatibilityCheck=false should suppress the check, but Android SDK
+         36.1.53 still emits XA0141 in some build orderings, so we also add it to NoWarn. -->
     <AndroidPageSize16KBCompatibilityCheck>false</AndroidPageSize16KBCompatibilityCheck>
+    <NoWarn>$(NoWarn);XA0141</NoWarn>
+    <!-- Disable ELF alignment patching for ALL configurations.
+         The custom PatchElfPageSize task can run concurrently with the Android packaging step
+         because MSBuild's BeforeTargets="Build" fires for every ABI sub-build, which often
+         overlaps with the main APK assembly pass.  Patching .so files in the NuGet cache while
+         they are being read and packed into the APK can corrupt the ZIP/signing structures,
+         producing an APK with a null certificate array (INSTALL_PARSE_FAILED_NO_CERTIFICATES).
+         TODO: Re-enable once ppy.Veldrid.SPIRV ships 16 KB-aligned native libraries so no
+               patching is needed at all, or once the build targets are re-sequenced so
+               patching always completes before packaging starts. -->
+    <PatchElfPageSizeEnabled>false</PatchElfPageSizeEnabled>
   </PropertyGroup>
 
   <!-- Patch NuGet-provided .so files that ship with 4 KB ELF alignment to 16 KB.
@@ -26,10 +45,18 @@
     <RunAOTCompilation>true</RunAOTCompilation>
     <AndroidEnableProfiledAot>true</AndroidEnableProfiledAot>
     <SuppressTrimAnalysisWarnings>true</SuppressTrimAnalysisWarnings>
-    <!-- Disable ELF patching in Release to prevent signature corruption -->
-    <PatchElfPageSizeEnabled>false</PatchElfPageSizeEnabled>
     <PublishTrimmed>true</PublishTrimmed>
     <TrimMode>partial</TrimMode>
+    <!-- Strip IL bodies from AOT-compiled assemblies.  The runtime uses the native .so code
+         instead, and IL is only kept for non-AOT methods.  This can save 20-30 MB. -->
+    <AndroidStripILAfterAOT>true</AndroidStripILAfterAOT>
+    <!-- Compress managed assemblies inside the APK (LZ4).  Android extracts them on first run
+         but the download/APK size is significantly smaller. -->
+    <AndroidEnableAssemblyCompression>true</AndroidEnableAssemblyCompression>
+    <!-- Don't ship PDB files in the APK — they add ~15-20 MB.
+         Stack traces still work via embedded metadata. -->
+    <DebugType>none</DebugType>
+    <DebugSymbols>false</DebugSymbols>
   </PropertyGroup>
 
   <ItemGroup Condition="'$(Configuration)' == 'Release'">
@@ -56,10 +83,13 @@
   </PropertyGroup>
 
   <!-- Fix for .NET 10 Android AOT misclassifying non-managed assets in runtime pack.
-       This is critical for Android 16 (API 36) which has stricter manifest/parsing rules.
-       We hook into multiple stages to ensure all native assets (including BASS and native bridge)
-       are correctly identified before the optimization/signing phases. -->
-  <Target Name="FixRuntimePackAssetTypes" AfterTargets="ResolveRuntimePackAssets;ComputeFilesToPublish;ComputeResolvedFilesToPublishList">
+       This is critical for Android 16 (API 36) Release/AOT builds where the linker expects
+       all non-managed assets to be marked as native before the optimization/signing phases.
+       Scoped to Release only — running this during Debug builds can interfere with how the
+       Android SDK classifies signing-related items, leading to APKs with null certificate
+       arrays (INSTALL_PARSE_FAILED_NO_CERTIFICATES). -->
+  <Target Name="FixRuntimePackAssetTypes" AfterTargets="ResolveRuntimePackAssets;ComputeFilesToPublish;ComputeResolvedFilesToPublishList"
+          Condition="'$(Configuration)' == 'Release'">
     <ItemGroup>
       <RuntimePackAsset Update="@(RuntimePackAsset)" Condition="'%(Extension)' != '.dll' AND '%(Extension)' != '.pdb'">
         <AssetType>native</AssetType>

osu.Android/AndroidManifest.xml

@@ -1,7 +1,7 @@
 <?xml version='1.0' encoding='utf-8'?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="sh.ppy.osulazer" android:installLocation="auto">
 	<uses-sdk android:minSdkVersion="33" android:targetSdkVersion="36" />
-	<application android:extractNativeLibs="true" android:allowBackup="true" android:supportsRtl="true" android:label="osu!" android:icon="@mipmap/ic_launcher" android:roundIcon="@mipmap/ic_launcher" android:largeHeap="true">
+	<application android:extractNativeLibs="false" android:allowBackup="true" android:supportsRtl="true" android:label="osu!" android:icon="@mipmap/ic_launcher" android:roundIcon="@mipmap/ic_launcher" android:largeHeap="true">
         <provider android:name="androidx.core.content.FileProvider" android:authorities="sh.ppy.osulazer.fileprovider" android:grantUriPermissions="true" android:exported="false">
             <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/filepaths" />
         </provider>

osu.Android/osu.Android.csproj

@@ -27,10 +27,10 @@
     <None Remove="Native\CMakeLists.txt" />
   </ItemGroup>
   <!-- Include pre-built native libraries when present (built by the release workflow or local NDK build).
-       When absent, native features (Oboe audio, Vulkan probe) are gracefully disabled at runtime. -->
+       When absent, native features (Oboe audio, Vulkan probe) are gracefully disabled at runtime.
+       x86 removed — only arm64 and arm32 are shipped (see RuntimeIdentifiers in osu.Android.props). -->
   <ItemGroup>
     <AndroidNativeLibrary Include="libs\arm64-v8a\libosu_native.so" Condition="Exists('libs\arm64-v8a\libosu_native.so')" Abi="arm64-v8a" />
     <AndroidNativeLibrary Include="libs\armeabi-v7a\libosu_native.so" Condition="Exists('libs\armeabi-v7a\libosu_native.so')" Abi="armeabi-v7a" />
-    <AndroidNativeLibrary Include="libs\x86\libosu_native.so" Condition="Exists('libs\x86\libosu_native.so')" Abi="x86" />
   </ItemGroup>
 </Project>