From 4ceed899a3d1e05b2a2afe94d9c622f08b64d8ec Mon Sep 17 00:00:00 2001
From: Julien Couvreur <jcouv@microsoft.com>
Date: Fri, 30 Sep 2022 13:01:31 -0700
Subject: [PATCH] Add instrumentation to investigate flakiness in
 ConstantFolding_01

---
 .../Test/Emit2/Emit/NumericIntPtrTests.cs     |  6 +++--
 src/Compilers/Test/Core/CommonTestBase.cs     |  2 ++
 .../Test/Core/CompilationVerifier.cs          | 27 +++++++++++++++++--
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/src/Compilers/CSharp/Test/Emit2/Emit/NumericIntPtrTests.cs b/src/Compilers/CSharp/Test/Emit2/Emit/NumericIntPtrTests.cs
index 05b30719ed928..2a427023d05ce 100644
--- a/src/Compilers/CSharp/Test/Emit2/Emit/NumericIntPtrTests.cs
+++ b/src/Compilers/CSharp/Test/Emit2/Emit/NumericIntPtrTests.cs
@@ -9006,7 +9006,8 @@ static void Main()
                 var refA = comp.EmitToImageReference();
                 comp = CreateEmptyCompilation(sourceB, references: new[] { refA, mscorlibRefWithoutSharing }, options: TestOptions.ReleaseExe, parseOptions: TestOptions.Regular9);
 
-                CompileAndVerify(comp, expectedOutput: expectedResult);
+                // Investigating flaky IL verification issue. Tracked by https://github.com/dotnet/roslyn/issues/63782
+                CompileAndVerify(comp, expectedOutput: expectedResult, verify: Verification.PassesOrFailFast);
                 Assert.NotNull(expectedResult);
             }
 
@@ -9040,7 +9041,8 @@ static void Main()
                     return;
                 }
 
-                CompileAndVerify(comp, expectedOutput: expectedResult).VerifyDiagnostics(expectedDiagnostics);
+                // Investigating flaky IL verification issue. Tracked by https://github.com/dotnet/roslyn/issues/63782
+                CompileAndVerify(comp, expectedOutput: expectedResult, verify: Verification.PassesOrFailFast).VerifyDiagnostics(expectedDiagnostics);
                 Assert.NotNull(expectedResult);
             }
         }
diff --git a/src/Compilers/Test/Core/CommonTestBase.cs b/src/Compilers/Test/Core/CommonTestBase.cs
index 6ebb554eb620a..df25bfa36e7a3 100644
--- a/src/Compilers/Test/Core/CommonTestBase.cs
+++ b/src/Compilers/Test/Core/CommonTestBase.cs
@@ -32,6 +32,8 @@ public enum Verification
         FailsPEVerify = 1 << 2,
         FailsILVerify = 1 << 3,
         Fails = FailsPEVerify | FailsILVerify,
+
+        PassesOrFailFast = 1 << 4,
     }
 
     /// <summary>
diff --git a/src/Compilers/Test/Core/CompilationVerifier.cs b/src/Compilers/Test/Core/CompilationVerifier.cs
index 82a5f9c2209b5..39fa8c39f91b5 100644
--- a/src/Compilers/Test/Core/CompilationVerifier.cs
+++ b/src/Compilers/Test/Core/CompilationVerifier.cs
@@ -160,6 +160,18 @@ void listMethodsInType(ICSharpCode.Decompiler.TypeSystem.ITypeDefinition type, D
             }
         }
 
+        public string DumpIL()
+        {
+            var output = new ICSharpCode.Decompiler.PlainTextOutput();
+            using var testEnvironment = RuntimeEnvironmentFactory.Create(_dependencies);
+            string mainModuleFullName = Emit(testEnvironment, manifestResources: null, EmitOptions.Default);
+            using var moduleMetadata = ModuleMetadata.CreateFromImage(testEnvironment.GetMainImage());
+            var peFile = new PEFile(mainModuleFullName, moduleMetadata.Module.PEReaderOpt);
+            var disassembler = new ICSharpCode.Decompiler.Disassembler.ReflectionDisassembler(output, default);
+            disassembler.WriteModuleContents(peFile);
+            return output.ToString();
+        }
+
         /// <summary>
 		/// Asserts that the emitted IL for a type is the same as the expected IL.
 		/// Many core library types are in different assemblies on .Net Framework, and .Net Core.
@@ -214,10 +226,21 @@ public void Emit(
 
             string mainModuleName = Emit(testEnvironment, manifestResources, emitOptions);
             _allModuleData = testEnvironment.GetAllModuleData();
-            testEnvironment.Verify(peVerify);
+
+            try
+            {
+                testEnvironment.Verify(peVerify);
 #if NETCOREAPP
-            ILVerify(peVerify);
+                ILVerify(peVerify);
 #endif
+            }
+            catch (Exception)when(peVerify is Verification.PassesOrFailFast)
+            {
+                var il = DumpIL();
+                Console.WriteLine(il);
+
+                Environment.FailFast("Investigating flaky IL verification issue. Tracked by https://github.com/dotnet/roslyn/issues/63782");
+            }
 
             if (expectedSignatures != null)
             {