Analyzer can warn on more RequiresUnreferencedCode cases (#1897)

Add support in analyzer to detect RUC in overridden methods
Add support in analyzer to detect RUC in static constructors
Add test for overridden property

2 files changed, 31 insertions, 5 deletions

diff --git a/test/ILLink.RoslynAnalyzer.Tests/LinkerTestCases.cs b/test/ILLink.RoslynAnalyzer.Tests/LinkerTestCases.cs
index 15b28ae7a..c26f6f9a4 100644
--- a/test/ILLink.RoslynAnalyzer.Tests/LinkerTestCases.cs
+++ b/test/ILLink.RoslynAnalyzer.Tests/LinkerTestCases.cs
@@ -19,14 +19,13 @@ namespace ILLink.RoslynAnalyzer.Tests
 		{
 			switch (m.Identifier.ValueText) {
 			case "MethodWithDuplicateRequiresAttribute":
-			case "TestCovariantReturnCallOnDerived":
 			case "TestRequiresUnreferencedCodeOnlyThroughReflection":
-			case "TestStaticCctorRequiresUnreferencedCode":
-			case "TestStaticCtorMarkingIsTriggeredByFieldAccess":
-			case "TestTypeWhichOverridesMethodVirtualMethodRequiresUnreferencedCode":
 			case "TestRequiresInMethodFromCopiedAssembly":
 			case "TestRequiresThroughReflectionInMethodFromCopiedAssembly":
-			case "TestStaticCtorTriggeredByMethodCall":
+			// There is a discrepancy between the way linker and the analyzer represent the location of the error,
+			// linker will point to the method caller and the analyzer will point to a line of code.
+			// The TestTypeIsBeforeFieldInit scenario is supported by the analyzer, just the diagnostic message is different
+			// We verify the analyzer generating the right diagnostic in RequiresUnreferencedCodeAnalyzerTests.cs
 			case "TestTypeIsBeforeFieldInit":
 				return;
 			}
diff --git a/test/ILLink.RoslynAnalyzer.Tests/RequiresUnreferencedCodeAnalyzerTests.cs b/test/ILLink.RoslynAnalyzer.Tests/RequiresUnreferencedCodeAnalyzerTests.cs
index 275880ccb..34faf97fc 100644
--- a/test/ILLink.RoslynAnalyzer.Tests/RequiresUnreferencedCodeAnalyzerTests.cs
+++ b/test/ILLink.RoslynAnalyzer.Tests/RequiresUnreferencedCodeAnalyzerTests.cs
@@ -106,5 +106,32 @@ class C
 				VerifyCS.Diagnostic ().WithSpan (8, 3, 8, 19).WithArguments ("C.PropertyRequires.set", "Message for --setter PropertyRequires--", "")
 				);
 		}
+
+		[Fact]
+		public Task TypeIsBeforeFieldInit ()
+		{
+			var TypeIsBeforeFieldInit = @"
+using System.Diagnostics.CodeAnalysis;
+
+class C
+{
+	class TypeIsBeforeFieldInit
+	{
+		public static int field = AnnotatedMethod ();
+
+		[RequiresUnreferencedCode (""Message from --TypeIsBeforeFieldInit.AnnotatedMethod--"")]
+		public static int AnnotatedMethod () => 42;
+	}
+
+	static void TestTypeIsBeforeFieldInit ()
+	{
+		var x = TypeIsBeforeFieldInit.field + 42;
+	}
+}";
+			return VerifyRequiresUnreferencedCodeAnalyzer (TypeIsBeforeFieldInit,
+				// (8,29): warning IL2026: Using method 'C.TypeIsBeforeFieldInit.AnnotatedMethod()' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. Message from --TypeIsBeforeFieldInit.AnnotatedMethod--.
+				VerifyCS.Diagnostic ().WithSpan (8, 29, 8, 47).WithArguments ("C.TypeIsBeforeFieldInit.AnnotatedMethod()", "Message from --TypeIsBeforeFieldInit.AnnotatedMethod--", "")
+				);
+		}
 	}
 }