Resolving first part of System.Drawing.Common IlLink warnings (#54076)

* Resolving first part of System.Drawing.Common IlLink warnings

* Address PR feedback
Co-authored-by: NEric Erhardt <eric.erhardt@microsoft.com>

src/libraries/System.Drawing.Common/ref/System.Drawing.Common.cs

@@ -347,6 +347,7 @@ public partial class FontConverter : System.ComponentModel.TypeConverter
         public override object ConvertTo(System.ComponentModel.ITypeDescriptorContext? context, System.Globalization.CultureInfo? culture, object? value, System.Type destinationType) { throw null; }
         public override object CreateInstance(System.ComponentModel.ITypeDescriptorContext? context, System.Collections.IDictionary propertyValues) { throw null; }
         public override bool GetCreateInstanceSupported(System.ComponentModel.ITypeDescriptorContext? context) { throw null; }
+        [Diagnostics.CodeAnalysis.RequiresUnreferencedCode("The Type of value cannot be statically discovered. The public parameterless constructor or the 'Default' static field may be trimmed from the Attribute's Type.")]
         public override System.ComponentModel.PropertyDescriptorCollection GetProperties(System.ComponentModel.ITypeDescriptorContext? context, object? value, System.Attribute[]? attributes) { throw null; }
         public override bool GetPropertiesSupported(System.ComponentModel.ITypeDescriptorContext context) { throw null; }
         public sealed partial class FontNameConverter : System.ComponentModel.TypeConverter, System.IDisposable
@@ -792,6 +793,7 @@ public partial class ImageConverter : System.ComponentModel.TypeConverter
         public override bool CanConvertTo(System.ComponentModel.ITypeDescriptorContext? context, System.Type? destinationType) { throw null; }
         public override object ConvertFrom(System.ComponentModel.ITypeDescriptorContext? context, System.Globalization.CultureInfo? culture, object value) { throw null; }
         public override object ConvertTo(System.ComponentModel.ITypeDescriptorContext? context, System.Globalization.CultureInfo? culture, object? value, System.Type destinationType) { throw null; }
+        [Diagnostics.CodeAnalysis.RequiresUnreferencedCode("The Type of value cannot be statically discovered. The public parameterless constructor or the 'Default' static field may be trimmed from the Attribute's Type.")]
         public override System.ComponentModel.PropertyDescriptorCollection GetProperties(System.ComponentModel.ITypeDescriptorContext? context, object? value, System.Attribute[]? attributes) { throw null; }
         public override bool GetPropertiesSupported(System.ComponentModel.ITypeDescriptorContext? context) { throw null; }
     }

src/libraries/System.Drawing.Common/ref/System.Drawing.Common.csproj

-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);netcoreapp3.1;netstandard2.0;net461</TargetFrameworks>
     <IncludeInternalObsoleteAttribute>true</IncludeInternalObsoleteAttribute>
@@ -11,6 +11,9 @@
     <Compile Include="System.Drawing.Common.netstandard.cs" Condition="'$(TargetFrameworkIdentifier)' == '.NETStandard'" />
     <Compile Include="System.Drawing.Common.net461.cs" Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'" />
   </ItemGroup>
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net5.0'))">
+    <Compile Include="$(CoreLibSharedDir)System\Diagnostics\CodeAnalysis\RequiresUnreferencedCodeAttribute.cs" />
+  </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == '$(NetCoreAppCurrent)'">
     <ProjectReference Include="$(LibrariesProjectRoot)System.Collections.NonGeneric\ref\System.Collections.NonGeneric.csproj" />
     <ProjectReference Include="$(LibrariesProjectRoot)System.ComponentModel\ref\System.ComponentModel.csproj" />

src/libraries/System.Drawing.Common/src/ILLink/ILLink.Suppressions.xml

@@ -5,49 +5,13 @@
       <argument>ILLink</argument>
       <argument>IL2026</argument>
       <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.BitmapSelector.DoesAssemblyHaveCustomAttribute(System.Reflection.Assembly,System.String)</property>
+      <property name="Target">M:System.Drawing.BitmapSelector.SameAssemblyOptIn(System.Reflection.Assembly)</property>
     </attribute>
     <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
       <argument>ILLink</argument>
       <argument>IL2026</argument>
       <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.FontConverter.ConvertFrom(System.ComponentModel.ITypeDescriptorContext,System.Globalization.CultureInfo,System.Object)</property>
-    </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2026</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.FontConverter.GetProperties(System.ComponentModel.ITypeDescriptorContext,System.Object,System.Attribute[])</property>
-    </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2026</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.ImageConverter.GetProperties(System.ComponentModel.ITypeDescriptorContext,System.Object,System.Attribute[])</property>
-    </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2026</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.Printing.MarginsConverter.ConvertFrom(System.ComponentModel.ITypeDescriptorContext,System.Globalization.CultureInfo,System.Object)</property>
-    </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2026</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.Printing.MarginsConverter.ConvertTo(System.ComponentModel.ITypeDescriptorContext,System.Globalization.CultureInfo,System.Object,System.Type)</property>
-    </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2046</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.FontConverter.GetProperties(System.ComponentModel.ITypeDescriptorContext,System.Object,System.Attribute[])</property>
-    </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2046</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.ImageConverter.GetProperties(System.ComponentModel.ITypeDescriptorContext,System.Object,System.Attribute[])</property>
+      <property name="Target">M:System.Drawing.BitmapSelector.SatelliteAssemblyOptIn(System.Reflection.Assembly)</property>
     </attribute>
     <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
       <argument>ILLink</argument>
@@ -115,17 +79,5 @@
       <property name="Scope">member</property>
       <property name="Target">M:System.Drawing.SafeNativeMethods.Gdip.GdipSaveImageToStream(System.Runtime.InteropServices.HandleRef,Interop.Ole32.IStream,System.Guid@,System.Runtime.InteropServices.HandleRef)</property>
     </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2026</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.MacSupport.GetHwndDelegate</property>
-    </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2075</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:System.Drawing.MacSupport.GetHwndDelegate</property>
-    </attribute>
   </assembly>
 </linker>
\ No newline at end of file

src/libraries/System.Drawing.Common/src/System.Drawing.Common.csproj

-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <DefineConstants>$(DefineConstants);DRAWING_NAMESPACE</DefineConstants>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
@@ -13,6 +13,10 @@
     <IncludeInternalObsoleteAttribute Condition="'$(TargetFramework)' != 'net461'">true</IncludeInternalObsoleteAttribute>
     <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsAnyOS)' == 'true' and '$(TargetFramework)' != 'net461'">SR.SystemDrawingCommon_PlatformNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net5.0'))">
+    <Compile Include="$(CoreLibSharedDir)System\Diagnostics\CodeAnalysis\RequiresUnreferencedCodeAttribute.cs" />
+    <Compile Include="$(CoreLibSharedDir)System\Diagnostics\CodeAnalysis\UnconditionalSuppressMessageAttribute.cs" />
+  </ItemGroup>
   <ItemGroup Condition="'$(TargetsAnyOS)' != 'true'">
     <Compile Include="System\Drawing\Bitmap.cs" />
     <Compile Include="System\Drawing\BitmapSuffixInSameAssemblyAttribute.cs" />

src/libraries/System.Drawing.Common/src/System/Drawing/BitmapSelector.cs

@@ -3,6 +3,7 @@
 
 namespace System.Drawing
 {
+    using System.Diagnostics.CodeAnalysis;
     using System.IO;
     using System.Reflection;
 
@@ -84,6 +85,7 @@ public static string GetFileName(string originalPath)
             return stream;
         }
 
+        [RequiresUnreferencedCode("Calls Assembly.GetType which may be trimmed")]
         private static bool DoesAssemblyHaveCustomAttribute(Assembly assembly, string typeName)
         {
             return DoesAssemblyHaveCustomAttribute(assembly, assembly.GetType(typeName));

src/libraries/System.Drawing.Common/src/System/Drawing/FontConverter.cs

@@ -5,6 +5,7 @@
 using System.ComponentModel;
 using System.ComponentModel.Design.Serialization;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Drawing.Text;
 using System.Globalization;
 using System.Reflection;
@@ -168,7 +169,7 @@ public override object ConvertTo(ITypeDescriptorContext? context, CultureInfo? c
                 {
                     try
                     {
-                        fontSize = (float)TypeDescriptor.GetConverter(typeof(float)).ConvertFromString(context, culture, unitTokens.size);
+                        fontSize = (float)GetFloatConverter().ConvertFromString(context, culture, unitTokens.size);
                     }
                     catch
                     {
@@ -207,6 +208,10 @@ public override object ConvertTo(ITypeDescriptorContext? context, CultureInfo? c
             }
 
             return new Font(fontName, fontSize, fontStyle, units);
+
+            [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:RequiresUnreferencedCode",
+                Justification = "TypeDescriptor.GetConverter is safe for primitive types.")]
+            static TypeConverter GetFloatConverter() => TypeDescriptor.GetConverter(typeof(float));
         }
 
         private (string?, string?) ParseSizeTokens(string text, char separator)
@@ -360,6 +365,7 @@ public override object CreateInstance(ITypeDescriptorContext? context, IDictiona
 
         public override bool GetCreateInstanceSupported(ITypeDescriptorContext? context) => true;
 
+        [RequiresUnreferencedCode("The Type of value cannot be statically discovered. The public parameterless constructor or the 'Default' static field may be trimmed from the Attribute's Type.")]
         public override PropertyDescriptorCollection GetProperties(
             ITypeDescriptorContext? context,
             object? value,

src/libraries/System.Drawing.Common/src/System/Drawing/ImageConverter.cs

@@ -4,6 +4,7 @@
 using System.Buffers.Binary;
 using System.ComponentModel;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Drawing.Imaging;
 using System.Globalization;
 using System.IO;
@@ -102,6 +103,7 @@ public override object ConvertTo(ITypeDescriptorContext? context, CultureInfo? c
             return null;
         }
 
+        [RequiresUnreferencedCode("The Type of value cannot be statically discovered. The public parameterless constructor or the 'Default' static field may be trimmed from the Attribute's Type.")]
         public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext? context, object? value, Attribute[]? attributes)
         {
             return TypeDescriptor.GetProperties(typeof(Image), attributes);

src/libraries/System.Drawing.Common/src/System/Drawing/Printing/MarginsConverter.cs

@@ -64,7 +64,7 @@ public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destina
                     char sep = culture.TextInfo.ListSeparator[0];
                     string[] tokens = text.Split(sep);
                     int[] values = new int[tokens.Length];
-                    TypeConverter intConverter = TypeDescriptor.GetConverter(typeof(int));
+                    TypeConverter intConverter = GetIntConverter();
                     for (int i = 0; i < values.Length; i++)
                     {
                         // Note: ConvertFromString will raise exception if value cannot be converted.
@@ -80,6 +80,10 @@ public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destina
             return base.ConvertFrom(context, culture, value);
         }
 
+        [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:RequiresUnreferencedCode",
+            Justification = "TypeDescriptor.GetConverter is safe for primitive types.")]
+        private static TypeConverter GetIntConverter() => TypeDescriptor.GetConverter(typeof(int));
+
         /// <summary>
         /// Converts the given object to another type. The most common types to convert
         /// are to and from a string object. The default implementation will make a call
@@ -102,7 +106,7 @@ public override object ConvertTo(ITypeDescriptorContext? context, CultureInfo? c
                         culture = CultureInfo.CurrentCulture;
                     }
                     string sep = culture.TextInfo.ListSeparator + " ";
-                    TypeConverter intConverter = TypeDescriptor.GetConverter(typeof(int));
+                    TypeConverter intConverter = GetIntConverter();
                     string[] args = new string[4];
                     int nArg = 0;