Remove unnecessary "return 100"s from tests

src/tests/Common/XUnitWrapperGenerator/Descriptors.cs

@@ -18,4 +18,13 @@ public static class Descriptors
             "XUnitWrapperGenerator",
             DiagnosticSeverity.Warning,
             isEnabledByDefault: true);
+
+    public static readonly DiagnosticDescriptor XUWG1002 =
+        new DiagnosticDescriptor(
+            "XUW1002",
+            "Tests should not unconditionally return 100",
+            "Tests should not unconditionally return 100. Convert to a void return.",
+            "XUnitWrapperGenerator",
+            DiagnosticSeverity.Warning,
+            isEnabledByDefault: true);
 }

src/tests/Common/XUnitWrapperGenerator/XUnitWrapperGenerator.cs

@@ -118,6 +118,53 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
 
         var allTests = testsInSource.Collect().Combine(testsInReferencedAssemblies.Collect()).Combine(outOfProcessTests.Collect()).SelectMany((tests, ct) => tests.Left.Left.AddRange(tests.Left.Right).AddRange(tests.Right));
 
+        context.RegisterImplementationSourceOutput(
+            methodsInSource
+            .Combine(context.AnalyzerConfigOptionsProvider)
+            .Where(data =>
+            {
+                var (_, configOptions) = data;
+                return configOptions.GlobalOptions.InMergedTestDirectory();
+            }),
+            static (context, data) =>
+            {
+                var (method, _) = data;
+
+                // Only check test methods
+                bool found = false;
+                foreach (var attr in method.GetAttributesOnSelfAndContainingSymbols())
+                {
+                    switch (attr.AttributeClass?.ToDisplayString())
+                    {
+                        case "Xunit.ConditionalFactAttribute":
+                        case "Xunit.FactAttribute":
+                        case "Xunit.ConditionalTheoryAttribute":
+                        case "Xunit.TheoryAttribute":
+                            found = true;
+                            break;
+                    }
+                }
+                if (!found) return;
+
+                // Find methods where all returns are the literal 100 (and there is at least one return)
+                if (method.DeclaringSyntaxReferences.IsEmpty) return;
+
+                found = false;
+                foreach (SyntaxReference node in method.DeclaringSyntaxReferences.Where(n => n != null))
+                {
+                    foreach (ReturnStatementSyntax rs in node.GetSyntax(context.CancellationToken).DescendantNodes().OfType<ReturnStatementSyntax>())
+                    {
+                        if (rs.Expression == null) continue;
+                        found = true;
+                        if (rs.Expression is LiteralExpressionSyntax les && les.Token.Value is int i && i == 100) continue;
+                        return;
+                    }
+                }
+
+                if (!found) return;
+                context.ReportDiagnostic(Diagnostic.Create(Descriptors.XUWG1002, method.Locations[0]));
+            });
+
         context.RegisterImplementationSourceOutput(
             allTests
             .Combine(context.AnalyzerConfigOptionsProvider)
@@ -845,6 +892,12 @@ private static ImmutableArray<ITestInfo> CreateTestCases(IMethodSymbol method, L
                 case "Xunit.InlineDataAttribute":
                     {
                         var args = attr.ConstructorArguments[0].Values;
+                        if (args == null)
+                        {
+                            // This can happen with something like InlineData(default(MyStruct)).
+                            // csc will already report an error, but we should not crash.
+                            continue;
+                        }
                         if (method.Parameters.Length != args.Length)
                         {
                             // Emit diagnostic

src/tests/JIT/CodeGenBringUpTests/Call1.cs

@@ -8,21 +8,10 @@
 using Xunit;
 public class BringUpTest_Call1
 {
-    const int Pass = 100;
-    const int Fail = -1;
-
     [MethodImplAttribute(MethodImplOptions.NoInlining)]
-    internal static void  M() { Console.WriteLine("Hello"); }
+    internal static void M() { Console.WriteLine("Hello"); }
     [MethodImplAttribute(MethodImplOptions.NoInlining)]
-    internal static void  Call1()
-    {
-        M();
-    }
     [Fact]
-    public static int TestEntryPoint()
-    {
-        Call1();
-        return 100;
-    }
+    public static void Call1() => M();
 }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Base_1.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<int>(3);
             new DerivedClass<int>(8);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Base_2.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<int>("NotNull");
             new DerivedClass<int>(null);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Base_3.cs

@@ -18,10 +18,9 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<int>(7);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Base_4.cs

@@ -18,10 +18,9 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<int>(7);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Base_6.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<Reftype>();
             new DerivedClass<Valuetype>();
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Peer_1.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<int>(3);
             new DerivedClass<int>(8);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Peer_2.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<int>("NotNull");
             new DerivedClass<int>(null);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Peer_3.cs

@@ -18,10 +18,9 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<int>(7);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Peer_4.cs

@@ -18,10 +18,9 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<int>(7);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Generic_Test_CSharp_Peer_6.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass<Reftype>();
             new DerivedClass<Valuetype>();
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Test_CSharp_Base_1.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass(3);
             new DerivedClass(8);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Test_CSharp_Base_2.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass("NotNull");
             new DerivedClass(null);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Test_CSharp_Base_3.cs

@@ -18,10 +18,9 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass(7);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Test_CSharp_Base_4.cs

@@ -18,10 +18,9 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass(7);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Test_CSharp_Peer_1.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass(3);
             new DerivedClass(8);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Test_CSharp_Peer_2.cs

@@ -18,11 +18,10 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass("NotNull");
             new DerivedClass(null);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Test_CSharp_Peer_3.cs

@@ -18,10 +18,9 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass(7);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/CheckedCtor/Test_CSharp_Peer_4.cs

@@ -18,10 +18,9 @@ namespace Test
     public static class App
     {
         [Fact]
-        public static int TestEntryPoint()
+        public static void TestEntryPoint()
         {
             new DerivedClass(7);
-            return 100;
         }
     }
 

src/tests/JIT/Directed/LoopAlignment/LoopsToProcess.cs

@@ -136,9 +136,8 @@ internal void Method0()
         }
     }
     [Fact]
-    public static int TestEntryPoint()
+    public static void TestEntryPoint()
     {
         new TestClass_Loops().Method0();
-        return 100;
     }
 }

src/tests/JIT/Directed/StructABI/StructWithOverlappingFields.cs

@@ -67,7 +67,9 @@ public FourByteStruct(int val)
 
     public class Program
     {
-        static void TestClass(int initVal)
+        [Theory]
+        [InlineData(2)]
+        public static void TestClass(int initVal)
         {
             FourByteClass fb = new FourByteClass(initVal);
             fb.fval = 0;
@@ -93,7 +95,9 @@ static void TestClass(int initVal)
             Debug.Assert(cse_val_2 == 52);
         }
 
-        static void TestStruct(int initVal)
+        [Theory]
+        [InlineData(2)]
+        public static void TestStruct(int initVal)
         {
             FourByteStruct fb = new FourByteStruct(initVal);
             fb.fval = 0;
@@ -118,13 +122,5 @@ static void TestStruct(int initVal)
             Debug.Assert(cse_uval_2 == 7);
             Debug.Assert(cse_val_2 == 52);
         }
-
-        [Fact]
-        public static int TestEntryPoint()
-        {
-            TestClass(2);
-            TestStruct(2);
-            return 100;
-        }
     }
 }

src/tests/JIT/Directed/StructABI/structreturn.cs

@@ -1813,13 +1813,12 @@ public static void Test()
 public class TestStructs
 {
     [Fact]
-    public static int TestEntryPoint()
+    public static void TestEntryPoint()
     {
         TestStructReturns.Test();
         TestUnsafeCasts.Test();
         TestMergeReturnBlocks.Test();
         TestHFAandHVA.Test();
         TestNon2PowerStructs.Test();
-        return 100;
     }
 }