Fixes removal of unused assembly references for linked assemblies (#1683)

16 files changed, 266 insertions, 6 deletions

diff --git a/test/Mono.Linker.Tests.Cases.Expectations/Metadata/SetupCompileAfterAttribute.cs b/test/Mono.Linker.Tests.Cases.Expectations/Metadata/SetupCompileAfterAttribute.cs
index 199d9b495..54bcd6ca0 100644
--- a/test/Mono.Linker.Tests.Cases.Expectations/Metadata/SetupCompileAfterAttribute.cs
+++ b/test/Mono.Linker.Tests.Cases.Expectations/Metadata/SetupCompileAfterAttribute.cs
@@ -8,7 +8,7 @@ namespace Mono.Linker.Tests.Cases.Expectations.Metadata
 	[AttributeUsage (AttributeTargets.Class, AllowMultiple = true)]
 	public class SetupCompileAfterAttribute : BaseMetadataAttribute
 	{
-		public SetupCompileAfterAttribute (string outputName, string[] sourceFiles, string[] references = null, string[] defines = null, object[] resources = null, string additionalArguments = null, string compilerToUse = null)
+		public SetupCompileAfterAttribute (string outputName, string[] sourceFiles, string[] references = null, string[] defines = null, object[] resources = null, string additionalArguments = null, string compilerToUse = null, bool addAsReference = true, bool removeFromLinkerInput = false)
 		{
 			if (sourceFiles == null)
 				throw new ArgumentNullException (nameof (sourceFiles));
diff --git a/test/Mono.Linker.Tests.Cases/Mono.Linker.Tests.Cases.csproj b/test/Mono.Linker.Tests.Cases/Mono.Linker.Tests.Cases.csproj
index b3069ab7c..d3522b05e 100644
--- a/test/Mono.Linker.Tests.Cases/Mono.Linker.Tests.Cases.csproj
+++ b/test/Mono.Linker.Tests.Cases/Mono.Linker.Tests.Cases.csproj
@@ -26,6 +26,9 @@
     <Compile Remove="TypeForwarding\Dependencies\ForwarderLibrary_2.cs" />
     <Compile Remove="TypeForwarding\Dependencies\ForwarderLibrary_3.cs" />
     <Compile Remove="TypeForwarding\Dependencies\ImplementationLibrary_3.cs" />
+    <Compile Remove="TypeForwarding\Dependencies\TypeForwardersRewriteForwarders.cs" />
+    <Compile Remove="TypeForwarding\Dependencies\TypeForwardedIsUpdatedForMissingTypeFwd.cs" />
+    <Compile Remove="TypeForwarding\Dependencies\AssemblyReferenceIsRemovedWhenUnused_Library.cs" />
     <Compile Remove="CommandLine\Dependencies\CustomStepDummy.cs" />
     <Compile Remove="CommandLine\Dependencies\CustomStepUser.cs" />
     <Compile Remove="Logging\Dependencies\LogStep.cs" />
diff --git a/test/Mono.Linker.Tests.Cases/References/AssemblyReferenceIsRemovedWhenUnused.cs b/test/Mono.Linker.Tests.Cases/References/AssemblyReferenceIsRemovedWhenUnused.cs
new file mode 100644
index 000000000..56581f512
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/References/AssemblyReferenceIsRemovedWhenUnused.cs
@@ -0,0 +1,22 @@
+using Mono.Linker.Tests.Cases.Expectations.Assertions;
+using Mono.Linker.Tests.Cases.Expectations.Metadata;
+using Mono.Linker.Tests.Cases.References.Dependencies;
+
+namespace Mono.Linker.Tests.Cases.References
+{
+	[SetupCompileBefore ("library1.dll", new[] { "Dependencies/AssemblyReferenceIsRemovedWhenUnusedLib.cs" })]
+
+	[RemovedAssembly ("library1.dll")]
+	[RemovedAssemblyReference ("test", "library1")]
+	class AssemblyReferenceIsRemovedWhenUnused
+	{
+		public static void Main ()
+		{
+		}
+
+		static void Unused ()
+		{
+			new AssemblyReferenceIsRemovedWhenUnusedLib ().UsedMethod ();
+		}
+	}
+}
diff --git a/test/Mono.Linker.Tests.Cases/References/Dependencies/AssemblyReferenceIsRemovedWhenUnusedLib.cs b/test/Mono.Linker.Tests.Cases/References/Dependencies/AssemblyReferenceIsRemovedWhenUnusedLib.cs
new file mode 100644
index 000000000..72df62f7c
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/References/Dependencies/AssemblyReferenceIsRemovedWhenUnusedLib.cs
@@ -0,0 +1,17 @@
+using System;
+
+namespace Mono.Linker.Tests.Cases.References.Dependencies
+{
+	public class AssemblyReferenceIsRemovedWhenUnusedLib
+	{
+		public void UsedMethod ()
+		{
+			Console.WriteLine ("Used");
+		}
+
+		public void UnusedMethod ()
+		{
+			Console.WriteLine ("NotUsed");
+		}
+	}
+}
diff --git a/test/Mono.Linker.Tests.Cases/References/Dependencies/AssemblyReferenceIsRemovedWhenUnused_RefLibrary.cs b/test/Mono.Linker.Tests.Cases/References/Dependencies/AssemblyReferenceIsRemovedWhenUnused_RefLibrary.cs
new file mode 100644
index 000000000..249145ea4
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/References/Dependencies/AssemblyReferenceIsRemovedWhenUnused_RefLibrary.cs
@@ -0,0 +1,9 @@
+namespace Mono.Linker.Tests.Cases.References.Dependencies
+{
+	public class AssemblyReferenceIsRemovedWhenUnused
+	{
+		public static void UsedMethodLib ()
+		{
+		}
+	}
+}
diff --git a/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardedIsUpdatedForMissingTypeFwd.cs b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardedIsUpdatedForMissingTypeFwd.cs
new file mode 100644
index 000000000..7145725e4
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardedIsUpdatedForMissingTypeFwd.cs
@@ -0,0 +1 @@
+[assembly: System.Runtime.CompilerServices.TypeForwardedTo (typeof (Mono.Linker.Tests.Cases.TypeForwarding.C1))]
diff --git a/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardedIsUpdatedForMissingTypeLib.cs b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardedIsUpdatedForMissingTypeLib.cs
new file mode 100644
index 000000000..ec8389b0d
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardedIsUpdatedForMissingTypeLib.cs
@@ -0,0 +1,6 @@
+namespace Mono.Linker.Tests.Cases.TypeForwarding
+{
+	public class C1
+	{
+	}
+}
\ No newline at end of file
diff --git a/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardedIsUpdatedForMissingTypeLib2.cs b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardedIsUpdatedForMissingTypeLib2.cs
new file mode 100644
index 000000000..58dc0d77b
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardedIsUpdatedForMissingTypeLib2.cs
@@ -0,0 +1,6 @@
+namespace Mono.Linker.Tests.Cases.TypeForwarding
+{
+	public class C2
+	{
+	}
+}
\ No newline at end of file
diff --git a/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardersRewriteForwarders.cs b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardersRewriteForwarders.cs
new file mode 100644
index 000000000..cb79a2f0d
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardersRewriteForwarders.cs
@@ -0,0 +1,4 @@
+[assembly: System.Runtime.CompilerServices.TypeForwardedTo (typeof (Mono.Linker.Tests.Cases.TypeForwarding.C))]
+[assembly: System.Runtime.CompilerServices.TypeForwardedTo (typeof (Mono.Linker.Tests.Cases.TypeForwarding.G<>))]
+[assembly: System.Runtime.CompilerServices.TypeForwardedTo (typeof (Mono.Linker.Tests.Cases.TypeForwarding.I))]
+[assembly: System.Runtime.CompilerServices.TypeForwardedTo (typeof (Mono.Linker.Tests.Cases.TypeForwarding.S))]
\ No newline at end of file
diff --git a/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardersRewriteLib.cs b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardersRewriteLib.cs
new file mode 100644
index 000000000..6c5c01fff
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/TypeForwarding/Dependencies/TypeForwardersRewriteLib.cs
@@ -0,0 +1,24 @@
+namespace Mono.Linker.Tests.Cases.TypeForwarding
+{
+	public class C
+	{
+
+	}
+
+	public class G<T>
+	{
+		public class N
+		{
+		}
+	}
+
+	public struct S
+	{
+
+	}
+
+	public interface I
+	{
+		public void Test (C c);
+	}
+}
\ No newline at end of file
diff --git a/test/Mono.Linker.Tests.Cases/TypeForwarding/TypeForwardedIsUpdatedForMissingType.cs b/test/Mono.Linker.Tests.Cases/TypeForwarding/TypeForwardedIsUpdatedForMissingType.cs
new file mode 100644
index 000000000..a5e019cb0
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/TypeForwarding/TypeForwardedIsUpdatedForMissingType.cs
@@ -0,0 +1,33 @@
+using System;
+using Mono.Linker.Tests.Cases.Expectations.Assertions;
+using Mono.Linker.Tests.Cases.Expectations.Metadata;
+
+namespace Mono.Linker.Tests.Cases.TypeForwarding
+{
+	[SkipUnresolved (true)]
+	[KeepTypeForwarderOnlyAssemblies ("false")]
+	[SetupCompileBefore ("Lib.dll", new[] { "Dependencies/TypeForwardedIsUpdatedForMissingTypeLib.cs" })]
+	[SetupCompileBefore ("AnotherLibrary.dll", new[] { "Dependencies/TypeForwardedIsUpdatedForMissingTypeLib2.cs" })]
+
+	[SetupCompileAfter ("AnotherLibrary.dll", new[] { "Dependencies/TypeForwardedIsUpdatedForMissingTypeLib2.cs" })]
+	[SetupCompileAfter ("Implementation.dll", new[] { "Dependencies/TypeForwardedIsUpdatedForMissingTypeLib.cs" }, removeFromLinkerInput: true)]
+	[SetupCompileAfter ("Lib.dll", new[] { "Dependencies/TypeForwardedIsUpdatedForMissingTypeFwd.cs" }, references: new[] { "Implementation.dll" })]
+
+	public class TypeForwardedIsUpdatedForMissingType
+	{
+		public static void Main ()
+		{
+			Test (null);
+		}
+
+		// It's important that the assembly reference to AnotherLibrary is added before Lib
+		public void DependencyWhichIsRemovedFromAssemblyList (C2 c)
+		{
+		}
+
+		[Kept]
+		static void Test (C1 c)
+		{
+		}
+	}
+}
diff --git a/test/Mono.Linker.Tests.Cases/TypeForwarding/TypeForwardersRewrite.cs b/test/Mono.Linker.Tests.Cases/TypeForwarding/TypeForwardersRewrite.cs
new file mode 100644
index 000000000..754d2c282
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/TypeForwarding/TypeForwardersRewrite.cs
@@ -0,0 +1,130 @@
+using System;
+using Mono.Linker.Tests.Cases.Expectations.Assertions;
+using Mono.Linker.Tests.Cases.Expectations.Metadata;
+
+namespace Mono.Linker.Tests.Cases.TypeForwarding
+{
+	// Actions:
+	// link - This assembly, Forwarder.dll and Implementation.dll
+	[KeepTypeForwarderOnlyAssemblies ("false")]
+
+	[SetupLinkerArgument ("--skip-unresolved", "true")]
+
+	[SetupCompileArgument ("/unsafe")]
+	[SetupCompileBefore ("Forwarder.dll", new[] { "Dependencies/TypeForwardersRewriteLib.cs" })]
+
+	[SetupCompileAfter ("Implementation.dll", new[] { "Dependencies/TypeForwardersRewriteLib.cs" })]
+	[SetupCompileAfter ("Forwarder.dll", new[] { "Dependencies/TypeForwardersRewriteForwarders.cs" }, references: new[] { "Implementation.dll" })]
+
+	[RemovedAssembly ("Forwarder.dll")]
+	[RemovedAssemblyReference ("test", "Forwarder")]
+	unsafe class TypeForwardersRewrite
+	{
+		static void Main ()
+		{
+#if NETCOREAPP
+			Test (null);
+#endif
+			Test2 (null);
+			Test3<C> (ref c);
+			Test4 (null, null);
+			Test5 (null);
+			Test6<string> (null);
+			c = null;
+			g = null;
+			e += null;
+			I tc = new TC ();
+			tc.Test (null);
+			I ti = new TS ();
+			ti.Test (null);
+			var gc = new GC<TC> ();
+		}
+
+		[Kept]
+		static C c;
+		[Kept]
+		static G<C> g;
+
+		[Kept]
+		[KeptBackingField]
+		[KeptEventAddMethod]
+		[KeptEventRemoveMethod]
+		static event D e;
+
+		[Kept]
+		[KeptBaseType (typeof (MulticastDelegate))]
+		[KeptMember (".ctor(System.Object,System.IntPtr)")]
+		[KeptMember ("Invoke()")]
+		delegate C D ();
+
+#if NETCOREAPP
+		[Kept]
+		static void Test (delegate*<C, S*> arg)
+		{
+		}
+#endif
+
+		[Kept]
+		static C Test2 (C c)
+		{
+			C lv = null;
+			return lv;
+		}
+
+		[Kept]
+		static C[] Test3<T> (ref C c) where T : C
+		{
+			return null;
+		}
+
+		[Kept]
+		static G<C> Test4 (G<C>[] a, object b)
+		{
+			Console.WriteLine (typeof (C));
+			Console.WriteLine (typeof (G<>));
+			Console.WriteLine (typeof (G<>.N));
+			C c = (C) b;
+			Console.WriteLine (c);
+			return null;
+		}
+
+		[Kept]
+		static G<C>.N Test5 (G<C>.N arg)
+		{
+			return null;
+		}
+
+		[Kept]
+		static void Test6<T> (G<T>.N arg)
+		{
+		}
+
+		[Kept]
+		[KeptBaseType (typeof (C))]
+		[KeptMember (".ctor()")]
+		[KeptInterface (typeof (I))]
+		class TC : C, I
+		{
+			[Kept]
+			void I.Test (C c)
+			{
+			}
+		}
+
+		[Kept]
+		[KeptInterface (typeof (I))]
+		struct TS : I
+		{
+			[Kept]
+			public void Test (C c)
+			{
+			}
+		}
+
+		[Kept]
+		[KeptMember (".ctor()")]
+		class GC<T> where T : I
+		{
+		}
+	}
+}
diff --git a/test/Mono.Linker.Tests.Cases/TypeForwarding/UsedForwarderIsRemovedWhenLink.cs b/test/Mono.Linker.Tests.Cases/TypeForwarding/UsedForwarderIsRemovedWhenLink.cs
index deef0e497..23b8ddc1e 100644
--- a/test/Mono.Linker.Tests.Cases/TypeForwarding/UsedForwarderIsRemovedWhenLink.cs
+++ b/test/Mono.Linker.Tests.Cases/TypeForwarding/UsedForwarderIsRemovedWhenLink.cs
@@ -18,6 +18,7 @@ namespace Mono.Linker.Tests.Cases.TypeForwarding
 	[SetupCompileAfter ("Forwarder.dll", new[] { "Dependencies/ForwarderLibrary.cs" }, references: new[] { "Implementation.dll" })]
 
 	[RemovedAssembly ("Forwarder.dll")]
+	[RemovedAssemblyReference ("test", "Forwarder")]
 	[KeptMemberInAssembly ("Implementation.dll", typeof (ImplementationLibrary), "GetSomeValue()")]
 	[KeptMemberInAssembly ("Library.dll", typeof (LibraryUsingForwarder), "GetValueFromOtherAssembly()")]
 	class UsedForwarderIsRemovedWhenLink
diff --git a/test/Mono.Linker.Tests/Mono.Linker.Tests.csproj b/test/Mono.Linker.Tests/Mono.Linker.Tests.csproj
index 56c70481a..c9136c801 100644
--- a/test/Mono.Linker.Tests/Mono.Linker.Tests.csproj
+++ b/test/Mono.Linker.Tests/Mono.Linker.Tests.csproj
@@ -31,7 +31,7 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(MonoBuild)' == ''">
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="3.7.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="3.8.0" />
     <PackageReference Include="nunit" Version="3.12.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
     <!-- This reference is purely so that the linker can resolve this
diff --git a/test/Mono.Linker.Tests/TestCasesRunner/TestCaseCompiler.cs b/test/Mono.Linker.Tests/TestCasesRunner/TestCaseCompiler.cs
index d16becb12..92a25d2cd 100644
--- a/test/Mono.Linker.Tests/TestCasesRunner/TestCaseCompiler.cs
+++ b/test/Mono.Linker.Tests/TestCasesRunner/TestCaseCompiler.cs
@@ -63,10 +63,10 @@ namespace Mono.Linker.Tests.TestCasesRunner
 			// expectations assemblies because this would undermine our ability to inspect them for expected results during ResultChecking.  The UnityLinker UnresolvedHandling tests depend on this
 			// behavior of skipping the after test compile
 			if (outputDirectory != _sandbox.ExpectationsDirectory) {
+				CompileAfterTestCaseAssemblies (outputDirectory, originalCommonReferences, originalDefines, removeFromLinkerInputAssemblies);
+
 				foreach (var assemblyToRemove in removeFromLinkerInputAssemblies)
 					assemblyToRemove.DeleteIfExists ();
-
-				CompileAfterTestCaseAssemblies (outputDirectory, originalCommonReferences, originalDefines);
 			}
 
 			return testAssembly;
@@ -125,7 +125,7 @@ namespace Mono.Linker.Tests.TestCasesRunner
 			}
 		}
 
-		private void CompileAfterTestCaseAssemblies (NPath outputDirectory, NPath[] references, string[] defines)
+		private void CompileAfterTestCaseAssemblies (NPath outputDirectory, NPath[] references, string[] defines, IList<NPath> removeFromLinkerInputAssemblies)
 		{
 			foreach (var setupCompileInfo in _metadataProvider.GetSetupCompileAssembliesAfter ()) {
 				var options = CreateOptionsForSupportingAssembly (
@@ -135,7 +135,10 @@ namespace Mono.Linker.Tests.TestCasesRunner
 					references,
 					defines,
 					CollectSetupAfterResourcesFiles (setupCompileInfo));
-				CompileAssembly (options);
+				var output = CompileAssembly (options);
+
+				if (setupCompileInfo.RemoveFromLinkerInput)
+					removeFromLinkerInputAssemblies.Add (output);
 			}
 		}
 
diff --git a/test/Mono.Linker.Tests/TestCasesRunner/TestRunner.cs b/test/Mono.Linker.Tests/TestCasesRunner/TestRunner.cs
index 92eb964e4..677de6124 100644
--- a/test/Mono.Linker.Tests/TestCasesRunner/TestRunner.cs
+++ b/test/Mono.Linker.Tests/TestCasesRunner/TestRunner.cs
@@ -82,6 +82,7 @@ namespace Mono.Linker.Tests.TestCasesRunner
 
 				throw;
 			}
+
 			return new ManagedCompilationResult (inputAssemblyPath, expectationsAssemblyPath);
 		}