Update linker substitutions

dotnet · Jul 15, 2020 · bcda8cb · bcda8cb
1 parent af0f08e
commit bcda8cb
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Showing 4 changed files with 17 additions and 24 deletions.
diff --git a/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml b/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml
@@ -12,8 +12,8 @@
     <type fullname="System.LocalAppContextSwitches">
       <method signature="System.Boolean get_EnableUnsafeUTF7Encoding()" body="stub" value="false" feature="System.Text.Encoding.EnableUnsafeUTF7Encoding" featurevalue="false" />
     </type>
-    <type fullname="System.LocalAppContextSwitches">
-      <method signature="System.Boolean get_BinaryFormatterEnabled()" body="stub" value="false" feature="System.Runtime.Serialization.EnableUnsafeBinaryFormatterSerialization" featurevalue="false" />
+    <type fullname="System.Resources.ResourceReader">
+      <method signature="System.Boolean InitializeBinaryFormatter()" body="stub" value="false" feature="System.Runtime.Serialization.EnableUnsafeBinaryFormatterSerialization" featurevalue="false" />
     </type>
   </assembly>
 </linker>
diff --git a/src/libraries/System.Private.CoreLib/src/System/LocalAppContextSwitches.cs b/src/libraries/System.Private.CoreLib/src/System/LocalAppContextSwitches.cs
@@ -41,13 +41,6 @@ public static bool PreserveEventListnerObjectIdentity
             get => GetCachedSwitchValue("Switch.System.Diagnostics.EventSource.PreserveEventListnerObjectIdentity", ref s_preserveEventListnerObjectIdentity);
         }
 
-        private static int s_binaryFormatterEnabled;
-        public static bool BinaryFormatterEnabled
-        {
-            [MethodImpl(MethodImplOptions.AggressiveInlining)]
-            get => GetCachedSwitchValue("System.Runtime.Serialization.EnableUnsafeBinaryFormatterSerialization", ref s_binaryFormatterEnabled);
-        }
-
         private static int s_serializationGuard;
         public static bool SerializationGuard
         {

diff --git a/src/libraries/System.Private.CoreLib/src/System/Resources/ResourceReader.Core.cs b/src/libraries/System.Private.CoreLib/src/System/Resources/ResourceReader.Core.cs
@@ -51,7 +51,14 @@ private object DeserializeObject(int typeIndex)
 
             if (_binaryFormatter == null)
             {
-                InitializeBinaryFormatter();
+                if (!InitializeBinaryFormatter())
+                {
+                    // The linker trimmed away the BinaryFormatter implementation and we can't call into it.
+                    // We'll throw an exception with the same text that BinaryFormatter would have thrown
+                    // had we been able to call into it. Keep this resource string in sync with the same
+                    // resource from the Formatters assembly.
+                    throw new NotSupportedException(SR.BinaryFormatter_SerializationDisallowed);
+                }
             }
 
             Type type = FindType(typeIndex);
@@ -66,19 +73,10 @@ private object DeserializeObject(int typeIndex)
         }
 
         // Issue https://github.com/dotnet/runtime/issues/39290 tracks finding an alternative to BinaryFormatter
-        private void InitializeBinaryFormatter()
+        private bool InitializeBinaryFormatter()
         {
-            // If BinaryFormatter support is hardcoded to disabled (e.g., wasm projects), early-exit now so
-            // that we don't run any of the reflection logic before. This also prevents the linker from seeing
-            // the GetType call below and keeping an unneeded reference to the Formatters assembly.
-            //
-            // Use a unique resource string so that we can provide a better error message in the case of
-            // "I tried to call into BinaryFormatter but was blocked." Keep this message text in sync with
-            // the same resource in the Formatters assembly.
-            if (!LocalAppContextSwitches.BinaryFormatterEnabled)
-            {
-                throw new NotSupportedException(SR.BinaryFormatter_SerializationDisallowed);
-            }
+            // If BinaryFormatter support is disabled for the app, the linker will replace this entire
+            // method body with "return false;", skipping all reflection code below.
 
             LazyInitializer.EnsureInitialized(ref s_binaryFormatterType, () =>
                 Type.GetType("System.Runtime.Serialization.Formatters.Binary.BinaryFormatter, System.Runtime.Serialization.Formatters, Version=0.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a",
@@ -96,6 +94,8 @@ private void InitializeBinaryFormatter()
             });
 
             _binaryFormatter = Activator.CreateInstance(s_binaryFormatterType!)!;
+
+            return true; // initialization successful
         }
 
         // generic method that we specialize at runtime once we've loaded the BinaryFormatter type

diff --git a/src/mono/netcore/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.wasm.xml b/src/mono/netcore/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.wasm.xml
@@ -9,8 +9,8 @@
     <type fullname="System.Runtime.CompilerServices.RuntimeFeature">
       <method signature="System.Boolean get_IsDynamicCodeCompiled()" body="stub" value="false" />
     </type>
-    <type fullname="System.LocalAppContextSwitches">
-      <method signature="System.Boolean get_BinaryFormatterEnabled()" body="stub" value="false" />
+    <type fullname="System.Resources.ResourceReader">
+      <method signature="System.Boolean InitializeBinaryFormatter()" body="stub" value="false" />
     </type>
   </assembly>
 </linker>