dotnet · idg10 · Mar 30, 2023 · Mar 30, 2023
diff --git a/Rx.NET/Source/Directory.build.targets b/Rx.NET/Source/Directory.build.targets
@@ -16,6 +16,9 @@
   <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
     <DefineConstants>$(DefineConstants);HAS_WINRT;NO_NULLABLE_ATTRIBUTES</DefineConstants>
   </PropertyGroup>
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('net6.0')) or $(TargetFramework.StartsWith('net7.0'))">
+    <DefineConstants>$(DefineConstants);HAS_TRIMMABILITY_ATTRIBUTES</DefineConstants>
+  </PropertyGroup>
   <PropertyGroup Condition="$(TargetFramework.StartsWith('net6.0-windows')) or $(TargetFramework.StartsWith('net7.0-windows'))">
     <DefineConstants>$(DefineConstants);HAS_WINRT;HAS_WINFORMS;HAS_WPF;HAS_DISPATCHER;DESKTOPCLR;WINDOWS;CSWINRT</DefineConstants>
   </PropertyGroup>

diff --git a/Rx.NET/Source/src/System.Reactive/Internal/Constants.cs b/Rx.NET/Source/src/System.Reactive/Internal/Constants.cs
@@ -4,7 +4,7 @@
 
 namespace System.Reactive
 {
-    // We can't make those based on the Strings_Core.resx file, because the ObsoleteAttribute needs a compile-time constant.
+    // We can't make those based on the Strings_Core.resx file, because attributes need a compile-time constant.
 
     internal static class Constants_Core
     {
@@ -15,6 +15,9 @@ internal static class Constants_Core
         public const string ObsoleteSchedulerThreadpool = ObsoleteRefactoring + " Consider using Scheduler.Default to obtain the platform's most appropriate pool-based scheduler. In order to access a specific pool-based scheduler, please add a reference to the System.Reactive.PlatformServices assembly for your target platform and use the appropriate scheduler in the System.Reactive.Concurrency namespace.";
 
         public const string ObsoleteSchedulerequired = "This instance property is no longer supported. Use CurrentThreadScheduler.IsScheduleRequired instead.";
+
+        internal const string AsQueryableTrimIncompatibilityMessage = "This type uses Queryable.AsQueryable, which is not compatible with trimming because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods, and those IEnumerable methods might be trimmed.";
+        internal const string EventReflectionTrimIncompatibilityMessage = "This member uses reflection to discover event members and associated delegate types.";
     }
 
     // We can't make those based on the Strings_*.resx file, because the ObsoleteAttribute needs a compile-time constant.

diff --git a/Rx.NET/Source/src/System.Reactive/Internal/ReflectionUtils.cs b/Rx.NET/Source/src/System.Reactive/Internal/ReflectionUtils.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT License.
 // See the LICENSE file in the project root for more information. 
 
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Reflection;
 
@@ -19,6 +20,9 @@ public static Delegate CreateDelegate(Type delegateType, object o, MethodInfo me
             return method.CreateDelegate(delegateType, o);
         }
 
+#if HAS_TRIMMABILITY_ATTRIBUTES
+    [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static void GetEventMethods<TSender, TEventArgs>(Type targetType, object? target, string eventName, out MethodInfo addMethod, out MethodInfo removeMethod, out Type delegateType, out bool isWinRT)
         {
             EventInfo? e;

diff --git a/Rx.NET/Source/src/System.Reactive/Linq/IQueryLanguage.cs b/Rx.NET/Source/src/System.Reactive/Linq/IQueryLanguage.cs
@@ -433,17 +433,53 @@ internal partial interface IQueryLanguage
         IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>(Action<EventHandler<TEventArgs>> addHandler, Action<EventHandler<TEventArgs>> removeHandler, IScheduler scheduler);
         IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TDelegate, TSender, TEventArgs>(Action<TDelegate> addHandler, Action<TDelegate> removeHandler);
         IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TDelegate, TSender, TEventArgs>(Action<TDelegate> addHandler, Action<TDelegate> removeHandler, IScheduler scheduler);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<object>> FromEventPattern(object target, string eventName);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<object>> FromEventPattern(object target, string eventName, IScheduler scheduler);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>(object target, string eventName);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>(object target, string eventName, IScheduler scheduler);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TSender, TEventArgs>(object target, string eventName);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TSender, TEventArgs>(object target, string eventName, IScheduler scheduler);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<object>> FromEventPattern(Type type, string eventName);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<object>> FromEventPattern(Type type, string eventName, IScheduler scheduler);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>(Type type, string eventName);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>(Type type, string eventName, IScheduler scheduler);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TSender, TEventArgs>(Type type, string eventName);
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TSender, TEventArgs>(Type type, string eventName, IScheduler scheduler);
 
         IObservable<TEventArgs> FromEvent<TDelegate, TEventArgs>(Func<Action<TEventArgs>, TDelegate> conversion, Action<TDelegate> addHandler, Action<TDelegate> removeHandler);

diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable.Events.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable.Events.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT License.
 // See the LICENSE file in the project root for more information. 
 
+using System.Diagnostics.CodeAnalysis;
 using System.Reactive.Concurrency;
 using System.Threading;
 
@@ -538,6 +539,9 @@ public static IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<object>> FromEventPattern(object target, string eventName)
         {
             if (target == null)
@@ -581,6 +585,9 @@ public static IObservable<EventPattern<object>> FromEventPattern(object target,
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<object>> FromEventPattern(object target, string eventName, IScheduler scheduler)
         {
             if (target == null)
@@ -633,6 +640,9 @@ public static IObservable<EventPattern<object>> FromEventPattern(object target,
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>(object target, string eventName)
         {
             if (target == null)
@@ -677,6 +687,9 @@ public static IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>(object target, string eventName, IScheduler scheduler)
         {
             if (target == null)
@@ -730,6 +743,9 @@ public static IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TSender, TEventArgs>(object target, string eventName)
         {
             if (target == null)
@@ -775,6 +791,9 @@ public static IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TS
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TSender, TEventArgs>(object target, string eventName, IScheduler scheduler)
         {
             if (target == null)
@@ -830,6 +849,9 @@ public static IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TS
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<object>> FromEventPattern(Type type, string eventName)
         {
             if (type == null)
@@ -873,6 +895,9 @@ public static IObservable<EventPattern<object>> FromEventPattern(Type type, stri
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<object>> FromEventPattern(Type type, string eventName, IScheduler scheduler)
         {
             if (type == null)
@@ -925,6 +950,9 @@ public static IObservable<EventPattern<object>> FromEventPattern(Type type, stri
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>(Type type, string eventName)
         {
             if (type == null)
@@ -969,6 +997,9 @@ public static IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>(Type type, string eventName, IScheduler scheduler)
         {
             if (type == null)
@@ -1022,6 +1053,9 @@ public static IObservable<EventPattern<TEventArgs>> FromEventPattern<TEventArgs>
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TSender, TEventArgs>(Type type, string eventName)
         {
             if (type == null)
@@ -1067,6 +1101,9 @@ public static IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TS
         /// </para>
         /// </remarks>
         /// <seealso cref="ToEventPattern"/>
+#if HAS_TRIMMABILITY_ATTRIBUTES
+        [RequiresUnreferencedCode(Constants_Core.EventReflectionTrimIncompatibilityMessage)]
+#endif
         public static IObservable<EventPattern<TSender, TEventArgs>> FromEventPattern<TSender, TEventArgs>(Type type, string eventName, IScheduler scheduler)
         {
             if (type == null)

diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable.Queryable.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable.Queryable.cs
@@ -4,8 +4,13 @@
 
 #pragma warning disable 1591
 
+using System.Diagnostics.CodeAnalysis;
+
 namespace System.Reactive.Linq
 {
+#if HAS_TRIMMABILITY_ATTRIBUTES
+    [RequiresUnreferencedCode(Constants_Core.AsQueryableTrimIncompatibilityMessage)]
+#endif
     public static partial class Qbservable
     {
 #pragma warning disable IDE1006 // Naming Styles: 3rd party code is known to reflect for this specific field name

diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Qbservable.Joins.cs b/Rx.NET/Source/src/System.Reactive/Linq/Qbservable.Joins.cs
@@ -45,7 +45,9 @@ public static QueryablePattern<TLeft, TRight> And<TLeft, TRight>(this IQbservabl
 #if CRIPPLED_REFLECTION
                     InfoOf(() => And<TLeft, TRight>(default, default)),
 #else
+#pragma warning disable IL2060 // ('System.Reflection.MethodInfo.MakeGenericMethod' can not be statically analyzed.) This gets the MethodInfo for the method running right now, so it can't have been trimmed
                     ((MethodInfo)MethodBase.GetCurrentMethod()!).MakeGenericMethod(typeof(TLeft), typeof(TRight)),
+#pragma warning restore IL2060
 #endif
                     left.Expression,
                     GetSourceExpression(right)
@@ -80,7 +82,9 @@ public static QueryablePlan<TResult> Then<TSource, TResult>(this IQbservable<TSo
 #if CRIPPLED_REFLECTION
                     InfoOf(() => Then<TSource, TResult>(default, default)),
 #else
+#pragma warning disable IL2060 // ('System.Reflection.MethodInfo.MakeGenericMethod' can not be statically analyzed.) This gets the MethodInfo for the method running right now, so it can't have been trimmed
                     ((MethodInfo)MethodBase.GetCurrentMethod()!).MakeGenericMethod(typeof(TSource), typeof(TResult)),
+#pragma warning restore IL2060
 #endif
                     source.Expression,
                     selector
@@ -114,7 +118,9 @@ public static IQbservable<TResult> When<TResult>(this IQbservableProvider provid
 #if CRIPPLED_REFLECTION
                     InfoOf(() => When<TResult>(default, default)),
 #else
+#pragma warning disable IL2060 // ('System.Reflection.MethodInfo.MakeGenericMethod' can not be statically analyzed.) This gets the MethodInfo for the method running right now, so it can't have been trimmed
                     ((MethodInfo)MethodBase.GetCurrentMethod()!).MakeGenericMethod(typeof(TResult)),
+#pragma warning restore IL2060
 #endif
                     Expression.Constant(provider, typeof(IQbservableProvider)),
                     Expression.NewArrayInit(
@@ -151,7 +157,9 @@ public static IQbservable<TResult> When<TResult>(this IQbservableProvider provid
 #if CRIPPLED_REFLECTION
                     InfoOf(() => When(default, default(IEnumerable<QueryablePlan<TResult>>))),
 #else
+#pragma warning disable IL2060 // ('System.Reflection.MethodInfo.MakeGenericMethod' can not be statically analyzed.) This gets the MethodInfo for the method running right now, so it can't have been trimmed
                     ((MethodInfo)MethodBase.GetCurrentMethod()!).MakeGenericMethod(typeof(TResult)),
+#pragma warning restore IL2060
 #endif
                     Expression.Constant(provider, typeof(IQbservableProvider)),
                     Expression.Constant(plans, typeof(IEnumerable<QueryablePlan<TResult>>))

diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Qbservable.cs b/Rx.NET/Source/src/System.Reactive/Linq/Qbservable.cs
@@ -56,7 +56,9 @@ public static IQbservable<TSource> ToQbservable<TSource>(this IQueryable<TSource
 #if CRIPPLED_REFLECTION
                     InfoOf(() => ToQbservable<TSource>(default)),
 #else
+#pragma warning disable IL2060 // ('System.Reflection.MethodInfo.MakeGenericMethod' can not be statically analyzed.) This gets the MethodInfo for the method running right now, so it can't have been trimmed
                     ((MethodInfo)MethodBase.GetCurrentMethod()!).MakeGenericMethod(typeof(TSource)),
+#pragma warning restore IL2060
 #endif
                     source.Expression
                 )
@@ -90,7 +92,9 @@ public static IQbservable<TSource> ToQbservable<TSource>(this IQueryable<TSource
 #if CRIPPLED_REFLECTION
                     InfoOf(() => ToQbservable<TSource>(default)),
 #else
+#pragma warning disable IL2060 // ('System.Reflection.MethodInfo.MakeGenericMethod' can not be statically analyzed.) This gets the MethodInfo for the method running right now, so it can't have been trimmed
                     ((MethodInfo)MethodBase.GetCurrentMethod()!).MakeGenericMethod(typeof(TSource)),
+#pragma warning restore IL2060
 #endif
                     source.Expression,
                     Expression.Constant(scheduler)