Merge pull request #162 from winnerspiros/fix-android-trimming-warnings-13825399711958778981

Resolve Android build warnings related to trimming and reflection

Author: winnerspiros

Program.cs

@@ -0,0 +1,10 @@
+using System;
+public class Host {
+    public event Action? MyEvent;
+}
+public class Program {
+    public static void Main() {
+        Host? h = new Host();
+        h?.MyEvent += () => {};
+    }
+}

final_fix.py

@@ -15,7 +15,6 @@
   </assembly>
   <assembly fullname="osu.Framework">
     <type fullname="osu.Framework.Audio.AudioManager">
-        <field name="ActiveMixers" />
         <property name="ActiveMixers" />
         <field name="TrackMixer" />
         <field name="SampleMixer" />

osu.Android/Linker.xml

@@ -102,7 +102,8 @@ public void RefreshMixers(int hardwareSampleRate)
             Console.WriteLine($"[osu!] Oboe redirector initialized successfully: master={masterMixer}, sources={string.Join(',', mixerHandles)}");
         }
 
-        [UnconditionalSuppressMessage("Trimming", "IL2067, IL2070, IL2072, IL2075, IL2106", Justification = "Preserved in Linker.xml")]
+        // Trimming warnings suppressed because AudioManager.ActiveMixers and related types are manually preserved in Linker.xml.
+        [UnconditionalSuppressMessage("Trimming", "IL2067, IL2070, IL2072, IL2075, IL2080, IL2106", Justification = "Preserved in Linker.xml")]
         private IEnumerable<AudioMixer> getActiveMixers()
         {
             Type type = typeof(AudioManager);
@@ -125,6 +126,24 @@ private IEnumerable<AudioMixer> getActiveMixers()
                         }
                     }
                 }
+
+                foreach (var prop in type.GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
+                {
+                    if (prop.CanRead && prop.PropertyType.IsGenericType && prop.PropertyType.GetGenericArguments().Contains(typeof(AudioMixer)))
+                    {
+                        object? val = prop.GetValue(audioManager);
+                        if (val is IEnumerable enumerable)
+                        {
+                            foreach (var item in enumerable)
+                            {
+                                if (item is AudioMixer mixer)
+                                    yield return mixer;
+                            }
+                            yield break;
+                        }
+                    }
+                }
+
                 type = type.BaseType!;
             }
         }
@@ -279,7 +298,8 @@ private void addMixer(AudioMixer? mixer)
                 mixerHandles.Add(handle);
         }
 
-        [UnconditionalSuppressMessage("Trimming", "IL2067, IL2070, IL2072, IL2075, IL2106", Justification = "Preserved in Linker.xml")]
+        // Trimming warnings suppressed because source handles (BASS mixer/stream/channel) are identified via reflection over types preserved in Linker.xml.
+        [UnconditionalSuppressMessage("Trimming", "IL2067, IL2070, IL2072, IL2075, IL2080, IL2106", Justification = "Preserved in Linker.xml")]
         private int findHandle(object obj)
         {
             Type? type = obj.GetType();

osu.Android/OboeAudioRedirector.cs

@@ -62,7 +62,8 @@ public OsuGameAndroid(OsuGameActivity activity)
             gameActivity = activity;
         }
 
-        [UnconditionalSuppressMessage("Trimming", "IL2067, IL2070, IL2072, IL2075, IL2106", Justification = "Preserved in Linker.xml")]
+        // Trimming warnings suppressed because reflection is used to bind to AudioManager.ActiveMixers, which is manually preserved in Linker.xml.
+        [UnconditionalSuppressMessage("Trimming", "IL2067, IL2070, IL2072, IL2075, IL2080, IL2106", Justification = "Preserved in Linker.xml")]
         protected override void LoadComplete()
         {
             base.LoadComplete();
@@ -391,7 +392,8 @@ public override void SetHost(GameHost host)
 
         protected override BatteryInfo CreateBatteryInfo() => new AndroidBatteryInfo();
 
-        [UnconditionalSuppressMessage("Trimming", "IL2067, IL2070, IL2072, IL2075, IL2106", Justification = "Preserved in Linker.xml")]
+        // Trimming warnings suppressed because reflection is used to unbind from AudioManager.ActiveMixers, which is manually preserved in Linker.xml.
+        [UnconditionalSuppressMessage("Trimming", "IL2067, IL2070, IL2072, IL2075, IL2080, IL2106", Justification = "Preserved in Linker.xml")]
         protected override void Dispose(bool isDisposing)
         {
             try

osu.Android/OsuGameAndroid.cs

@@ -214,7 +214,7 @@ public void BeginPlaying(long? scoreToken, GameplayState state, Score score)
             Schedule(() =>
             {
                 if (isPlaying)
-                    throw new InvalidOperationException($"Cannot invoke {nameof(BeginPlaying)} when already playing");
+                    return;
 
                 isPlaying = true;
 

osu.Game/Online/Spectator/SpectatorClient.cs

@@ -1,4 +1,4 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
 #nullable disable
@@ -18,7 +18,7 @@ public abstract partial class HitErrorMeter : CompositeDrawable, ISerialisableDr
     {
         protected HitWindows HitWindows { get; private set; }
 
-        [Resolved]
+        [Resolved(canBeNull: true)]
         private ScoreProcessor processor { get; set; }
 
         [Resolved]
@@ -44,7 +44,7 @@ protected override void LoadComplete()
 
             gameplayClockContainer?.OnSeek += Clear;
 
-            processor.NewJudgement += processorNewJudgement;
+            processor?.NewJudgement += processorNewJudgement;
         }
 
         // Scheduled as meter implementations are likely going to change/add drawables when reacting to this.