Add nowarn option

src/ILLink.Tasks/LinkTask.cs

@@ -51,11 +51,18 @@ public class ILLink : ToolTask
 
 		/// <summary>
 		///   The directory in which to place linked assemblies.
-		//    Maps to '-out'.
+		///    Maps to '-out'.
 		/// </summary>
 		[Required]
 		public ITaskItem OutputDirectory { get; set; }
 
+		/// <summary>
+		///	The subset of warnings that have to be turned off.
+		///	This has no effect if '--verbose' is used. Defaults to 'Analysis'.
+		///	Maps to '--nowarn'.
+		/// </summary>
+		public ITaskItem NoWarn { get; set; }
+
 		/// <summary>
 		///   A list of XML root descriptor files specifying linker
 		///   roots at a granular level. See the mono/linker
@@ -303,6 +310,9 @@ protected override string GenerateResponseFileCommands ()
 			if (OutputDirectory != null)
 				args.Append ("-out ").AppendLine (Quote (OutputDirectory.ItemSpec));
 
+			if (NoWarn != null)
+				args.Append ("--nowarn ").Append (NoWarn);
+
 			// Add global optimization arguments
 			if (_beforeFieldInit is bool beforeFieldInit)
 				SetOpt (args, "beforefieldinit", beforeFieldInit);

src/linker/Linker.Dataflow/FlowAnnotations.cs

@@ -162,12 +162,14 @@ TypeAnnotations BuildTypeAnnotations (TypeDefinition type)
 								paramAnnotations[0] = methodMemberTypes;
 							}
 						} else if (methodMemberTypes != DynamicallyAccessedMemberTypes.None) {
-							_context.LogWarning ($"The DynamicallyAccessedMembersAttribute is only allowed on method parameters, return value or generic parameters.", 2041, method);
+							_context.LogWarning ($"The DynamicallyAccessedMembersAttribute is only allowed on method parameters, return value or generic parameters.",
+								2041, method, subcategory: MessageSubCategory.DynamicDependency);
 						}
 					} else {
 						offset = 0;
 						if (methodMemberTypes != DynamicallyAccessedMemberTypes.None) {
-							_context.LogWarning ($"The DynamicallyAccessedMembersAttribute is only allowed on method parameters, return value or generic parameters.", 2041, method);
+							_context.LogWarning ($"The DynamicallyAccessedMembersAttribute is only allowed on method parameters, return value or generic parameters.",
+								2041, method, subcategory: MessageSubCategory.DynamicDependency);
 						}
 					}
 
@@ -247,7 +249,8 @@ TypeAnnotations BuildTypeAnnotations (TypeDefinition type)
 						}
 
 						if (annotatedMethods.Any (a => a.Method == setMethod)) {
-							_context.LogWarning ($"Trying to propagate DynamicallyAccessedMemberAttribute from property '{property.FullName}' to its setter '{setMethod}', but it already has such attribute on the 'value' parameter.", 2043, setMethod);
+							_context.LogWarning ($"Trying to propagate DynamicallyAccessedMemberAttribute from property '{property.FullName}' to its setter '{setMethod}', but it already has such attribute on the 'value' parameter.",
+								2043, setMethod, subcategory: MessageSubCategory.DynamicDependency);
 						} else {
 							int offset = setMethod.HasImplicitThis () ? 1 : 0;
 							if (setMethod.Parameters.Count > 0) {
@@ -274,7 +277,8 @@ TypeAnnotations BuildTypeAnnotations (TypeDefinition type)
 						}
 
 						if (annotatedMethods.Any (a => a.Method == getMethod)) {
-							_context.LogWarning ($"Trying to propagate DynamicallyAccessedMemberAttribute from property '{property.FullName}' to its getter '{getMethod}', but it already has such attribute on the return value.", 2043, getMethod);
+							_context.LogWarning ($"Trying to propagate DynamicallyAccessedMemberAttribute from property '{property.FullName}' to its getter '{getMethod}', but it already has such attribute on the return value.",
+								2043, getMethod, subcategory: MessageSubCategory.DynamicDependency);
 						} else {
 							annotatedMethods.Add (new MethodAnnotations (getMethod, null, annotation, null));
 						}
@@ -283,15 +287,17 @@ TypeAnnotations BuildTypeAnnotations (TypeDefinition type)
 					FieldDefinition backingField;
 					if (backingFieldFromGetter != null && backingFieldFromSetter != null &&
 						backingFieldFromGetter != backingFieldFromSetter) {
-						_context.LogWarning ($"Could not find a unique backing field for property '{property.FullName}' to propagate DynamicallyAccessedMembersAttribute. The backing fields from getter '{backingFieldFromGetter.FullName}' and setter '{backingFieldFromSetter.FullName}' are not the same.", 2042, property);
+						_context.LogWarning ($"Could not find a unique backing field for property '{property.FullName}' to propagate DynamicallyAccessedMembersAttribute. The backing fields from getter '{backingFieldFromGetter.FullName}' and setter '{backingFieldFromSetter.FullName}' are not the same.",
+							2042, property, subcategory: MessageSubCategory.DynamicDependency);
 						backingField = null;
 					} else {
 						backingField = backingFieldFromGetter ?? backingFieldFromSetter;
 					}
 
 					if (backingField != null) {
 						if (annotatedFields.Any (a => a.Field == backingField)) {
-							_context.LogWarning ($"Trying to propagate DynamicallyAccessedMemberAttribute from property '{property.FullName}' to its field '{backingField}', but it already has such attribute.", 2043, backingField);
+							_context.LogWarning ($"Trying to propagate DynamicallyAccessedMemberAttribute from property '{property.FullName}' to its field '{backingField}', but it already has such attribute.",
+								2043, backingField, subcategory: MessageSubCategory.DynamicDependency);
 						} else {
 							annotatedFields.Add (new FieldAnnotation (backingField, annotation));
 						}

src/linker/Linker.Dataflow/ReflectionMethodBodyScanner.cs

@@ -1248,7 +1248,7 @@ methodParams[argsParam] is ArrayValue arrayValue &&
 							message += " " + requiresUnreferencedCode.Url;
 						}
 
-						_context.LogWarning (message, 2026, callingMethodDefinition, operation.Offset);
+						_context.LogWarning (message, 2026, callingMethodDefinition, operation.Offset, MessageSubCategory.UnreferencedCode);
 					}
 
 					// To get good reporting of errors we need to track the origin of the value for all method calls

src/linker/Linker.Steps/DynamicDependencyLookupStep.cs

@@ -59,7 +59,8 @@ void ProcessDynamicDependencyAttributes (IMemberDefinition member)
 				if (!IsPreserveDependencyAttribute (ca.AttributeType))
 					continue;
 #if FEATURE_ILLINK
-				Context.LogWarning ($"PreserveDependencyAttribute is deprecated. Use DynamicDependencyAttribute instead.", 2033, member);
+				Context.LogWarning ($"PreserveDependencyAttribute is deprecated. Use DynamicDependencyAttribute instead.",
+					2033, member, subcategory: MessageSubCategory.PreserveDependency);
 #endif
 				if (ca.ConstructorArguments.Count != 3)
 					continue;
@@ -82,7 +83,8 @@ void ProcessDynamicDependencyAttributes (IMemberDefinition member)
 
 				var assembly = Context.Resolve (new AssemblyNameReference (dynamicDependency.AssemblyName, new Version ()));
 				if (assembly == null) {
-					Context.LogWarning ($"Unresolved assembly '{dynamicDependency.AssemblyName}' in DynamicDependencyAttribute on '{member}'", 2035, member);
+					Context.LogWarning ($"Unresolved assembly '{dynamicDependency.AssemblyName}' in DynamicDependencyAttribute on '{member}'",
+						2035, member, subcategory: MessageSubCategory.DynamicDependency);
 					continue;
 				}
 

src/linker/Linker.Steps/MarkStep.cs

@@ -579,7 +579,8 @@ void MarkDynamicDependency (DynamicDependency dynamicDependency, IMemberDefiniti
 			if (dynamicDependency.AssemblyName != null) {
 				assembly = _context.GetLoadedAssembly (dynamicDependency.AssemblyName);
 				if (assembly == null) {
-					_context.LogWarning ($"Unresolved assembly '{dynamicDependency.AssemblyName}' in DynamicDependencyAttribute on '{context}'", 2035, context);
+					_context.LogWarning ($"Unresolved assembly '{dynamicDependency.AssemblyName}' in DynamicDependencyAttribute on '{context}'",
+						2035, context, subcategory: MessageSubCategory.DynamicDependency);
 					return;
 				}
 			} else {
@@ -591,19 +592,22 @@ void MarkDynamicDependency (DynamicDependency dynamicDependency, IMemberDefiniti
 			if (dynamicDependency.TypeName is string typeName) {
 				type = DocumentationSignatureParser.GetTypeByDocumentationSignature (assembly, typeName);
 				if (type == null) {
-					_context.LogWarning ($"Unresolved type '{typeName}' in DynamicDependencyAttribute on '{context}'", 2036, context);
+					_context.LogWarning ($"Unresolved type '{typeName}' in DynamicDependencyAttribute on '{context}'",
+						2036, context, subcategory: MessageSubCategory.DynamicDependency);
 					return;
 				}
 			} else if (dynamicDependency.Type is TypeReference typeReference) {
 				type = typeReference.Resolve ();
 				if (type == null) {
-					_context.LogWarning ($"Unresolved type '{typeReference}' in DynamicDependencyAtribute on '{context}'", 2036, context);
+					_context.LogWarning ($"Unresolved type '{typeReference}' in DynamicDependencyAtribute on '{context}'",
+						2036, context, subcategory: MessageSubCategory.DynamicDependency);
 					return;
 				}
 			} else {
 				type = context.DeclaringType.Resolve ();
 				if (type == null) {
-					_context.LogWarning ($"Unresolved type '{context.DeclaringType}' in DynamicDependencyAttribute on '{context}'", 2036, context);
+					_context.LogWarning ($"Unresolved type '{context.DeclaringType}' in DynamicDependencyAttribute on '{context}'",
+						2036, context, subcategory: MessageSubCategory.DynamicDependency);
 					return;
 				}
 			}
@@ -612,14 +616,16 @@ void MarkDynamicDependency (DynamicDependency dynamicDependency, IMemberDefiniti
 			if (dynamicDependency.MemberSignature is string memberSignature) {
 				members = DocumentationSignatureParser.GetMembersByDocumentationSignature (type, memberSignature, acceptName: true);
 				if (!members.Any ()) {
-					_context.LogWarning ($"No members were resolved for '{memberSignature}'.", 2037, context);
+					_context.LogWarning ($"No members were resolved for '{memberSignature}'.",
+						2037, context, subcategory: MessageSubCategory.DynamicDependency);
 					return;
 				}
 			} else {
 				var memberTypes = dynamicDependency.MemberTypes;
 				members = DynamicallyAccessedMembersBinder.GetDynamicallyAccessedMembers (type, memberTypes);
 				if (!members.Any ()) {
-					_context.LogWarning ($"No members were resolved for '{memberTypes}'.", 2037, context);
+					_context.LogWarning ($"No members were resolved for '{memberTypes}'.",
+						2037, context, subcategory: MessageSubCategory.DynamicDependency);
 					return;
 				}
 			}
@@ -688,7 +694,8 @@ protected virtual void MarkUserDependency (MemberReference context, CustomAttrib
 				assembly = _context.GetLoadedAssembly (assemblyName);
 				if (assembly == null) {
 					_context.LogWarning (
-						$"Could not resolve '{assemblyName}' assembly dependency specified in a `PreserveDependency` attribute that targets method '{context.FullName}'", 2003, context.Resolve ());
+						$"Could not resolve '{assemblyName}' assembly dependency specified in a `PreserveDependency` attribute that targets method '{context.FullName}'",
+						2003, context.Resolve (), subcategory: MessageSubCategory.PreserveDependency);
 					return;
 				}
 			} else {
@@ -701,7 +708,8 @@ protected virtual void MarkUserDependency (MemberReference context, CustomAttrib
 
 				if (td == null) {
 					_context.LogWarning (
-						$"Could not resolve '{typeName}' type dependency specified in a `PreserveDependency` attribute that targets method '{context.FullName}'", 2004, context.Resolve ());
+						$"Could not resolve '{typeName}' type dependency specified in a `PreserveDependency` attribute that targets method '{context.FullName}'",
+						2004, context.Resolve (), subcategory: MessageSubCategory.PreserveDependency);
 					return;
 				}
 			} else {
@@ -735,7 +743,8 @@ protected virtual void MarkUserDependency (MemberReference context, CustomAttrib
 				return;
 
 			_context.LogWarning (
-				$"Could not resolve dependency member '{member}' declared in type '{td.FullName}' specified in a `PreserveDependency` attribute that targets method '{context.FullName}'", 2005, td);
+				$"Could not resolve dependency member '{member}' declared in type '{td.FullName}' specified in a `PreserveDependency` attribute that targets method '{context.FullName}'",
+				2005, td, subcategory: MessageSubCategory.PreserveDependency);
 		}
 
 		bool MarkDependencyMethod (TypeDefinition type, string name, string[] signature, in DependencyInfo reason, IMemberDefinition sourceLocationMember)

src/linker/Linker/Driver.cs

@@ -438,6 +438,17 @@ protected int SetupContext (ILogger customLogger = null)
 						context.OutputWarningSuppressions = true;
 						continue;
 
+					case "--nowarn":
+						string noWarnArgument = null;
+						if (!GetStringParam (token, l => noWarnArgument = l))
+							return -1;
+
+						if (!Enum.TryParse (typeof (NoWarn), noWarnArgument, true, out var noWarnEnum))
+							return -1;
+
+						context.DontWarn = (NoWarn) noWarnEnum;
+						continue;
+
 					case "--version":
 						Version ();
 						return 1;
@@ -998,6 +1009,9 @@ static void Usage ()
 			Console.WriteLine ("  -out PATH           Specify the output directory. Defaults to 'output'");
 			Console.WriteLine ("  --about             About the {0}", _linker);
 			Console.WriteLine ("  --verbose           Log messages indicating progress and warnings");
+			Console.WriteLine ("  --nowarn OPTION     Turn off all warnings or a predefined subset. Ignored if 'verbose' is used. Defaults to 'analysis'.");
+			Console.WriteLine ("                        all: Disable all warnings");
+			Console.WriteLine ("                        analysis: Disable dataflow analysis warnings");
 			Console.WriteLine ("  --version           Print the version number of the {0}", _linker);
 			Console.WriteLine ("  -help               Lists all linker options");
 			Console.WriteLine ("  @FILE               Read response file for more options");

src/linker/Linker/LinkContext.cs

@@ -30,6 +30,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.Linq;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 
@@ -174,6 +175,8 @@ public ISymbolWriterProvider SymbolWriterProvider {
 
 		public WarningSuppressionWriter WarningSuppressionWriter { get; }
 
+		public NoWarn DontWarn { get; set; }
+
 		public bool OutputWarningSuppressions { get; set; }
 
 		public UnconditionalSuppressMessageAttributeState Suppressions { get; set; }
@@ -229,6 +232,7 @@ public LinkContext (Pipeline pipeline, AssemblyResolver resolver, ReaderParamete
 			PInvokes = new List<PInvokeInfo> ();
 			Suppressions = new UnconditionalSuppressMessageAttributeState (this);
 			WarningSuppressionWriter = new WarningSuppressionWriter (this);
+			DontWarn = NoWarn.Analysis;
 
 			// See https://github.com/mono/linker/issues/612
 			const CodeOptimizations defaultOptimizations =
@@ -484,9 +488,22 @@ public bool IsOptimizationEnabled (CodeOptimizations optimization, AssemblyDefin
 
 		public void LogMessage (MessageContainer message)
 		{
-			if (!LogMessages || message == MessageContainer.Empty)
+			if (message == MessageContainer.Empty)
 				return;
 
+			if (!LogMessages && message.Category == MessageCategory.Warning) {
+				switch (DontWarn) {
+				case NoWarn.All:
+					return;
+
+				case NoWarn.Analysis:
+					if (MessageSubCategory.Analysis.Contains (message.SubCategory))
+						return;
+
+					break;
+				}
+			}
+
 			if (OutputWarningSuppressions && message.Category == MessageCategory.Warning && message.Origin?.MemberDefinition != null)
 				WarningSuppressionWriter.AddWarning (message.Code.Value, message.Origin?.MemberDefinition);
 
@@ -519,9 +536,6 @@ public void LogDiagnostic (string message)
 		/// <param name="subcategory">Optionally, further categorize this warning</param>
 		public void LogWarning (string text, int code, MessageOrigin origin, string subcategory = MessageSubCategory.None)
 		{
-			if (!LogMessages)
-				return;
-
 			var warning = MessageContainer.CreateWarningMessage (this, text, code, origin, subcategory);
 			LogMessage (warning);
 		}
@@ -562,9 +576,6 @@ public void LogWarning (string text, int code, string origin, string subcategory
 		/// <returns>New MessageContainer of 'Error' category</returns>
 		public void LogError (string text, int code, string subcategory = MessageSubCategory.None, MessageOrigin? origin = null)
 		{
-			if (!LogMessages)
-				return;
-
 			var error = MessageContainer.CreateErrorMessage (text, code, subcategory, origin);
 			LogMessage (error);
 		}

src/linker/Linker/LoggingReflectionPatternRecorder.cs

@@ -45,7 +45,7 @@ public void RecognizedReflectionAccessPattern (IMemberDefinition source, Instruc
 		public void UnrecognizedReflectionAccessPattern (IMemberDefinition source, Instruction sourceInstruction, IMetadataTokenProvider accessedItem, string message)
 		{
 			var origin = new MessageOrigin (source, sourceInstruction?.Offset);
-			_context.LogWarning (message, 2006, origin, "Unrecognized reflection pattern");
+			_context.LogWarning (message, 2006, origin, MessageSubCategory.UnrecognizedReflectionPattern);
 		}
 	}
 }

src/linker/Linker/MessageSubcategory.cs

@@ -6,7 +6,18 @@ namespace Mono.Linker
 {
 	public static class MessageSubCategory
 	{
+		public const string DynamicDependency = "Dynamic dependency";
 		public const string None = "";
+		public const string PreserveDependency = "Preserve dependency";
+		public const string UnrecognizedReflectionPattern = "Unrecognized reflection pattern";
+		public const string UnreferencedCode = "Unreferenced code";
 		public const string UnresolvedAssembly = "Unresolved assembly";
+
+		public static readonly string[] Analysis = {
+			DynamicDependency,
+			PreserveDependency,
+			UnrecognizedReflectionPattern,
+			UnreferencedCode
+		};
 	}
 }

src/linker/Linker/NoWarn.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Mono.Linker
+{
+	public enum NoWarn
+	{
+		// Turn off all warnings.
+		All,
+
+		// Turn off warnings having the DynamicDependency, PreserveDependency, 
+		// UnrecognizedReflectionPattern, or UnreferencedCode subcategory.
+		Analysis
+	}
+}

test/Mono.Linker.Tests.Cases/DataFlow/MethodThisDataFlow.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using Mono.Linker.Tests.Cases.Expectations.Assertions;
+using Mono.Linker.Tests.Cases.Expectations.Metadata;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -13,6 +14,7 @@
 namespace Mono.Linker.Tests.Cases.DataFlow
 {
 	[SkipKeptItemsValidation]
+	[SetupLinkerArgument ("--verbose")]
 	public class MethodThisDataFlow
 	{
 		public static void Main ()

test/Mono.Linker.Tests.Cases/DataFlow/PropertyDataFlow.cs

@@ -9,12 +9,14 @@
 using System.Runtime.CompilerServices;
 using System.Text;
 using Mono.Linker.Tests.Cases.Expectations.Assertions;
+using Mono.Linker.Tests.Cases.Expectations.Metadata;
 
 namespace Mono.Linker.Tests.Cases.DataFlow
 {
 	// Note: this test's goal is to validate that the product correctly reports unrecognized patterns
 	//   - so the main validation is done by the UnrecognizedReflectionAccessPattern attributes.
 	[SkipKeptItemsValidation]
+	[SetupLinkerArgument ("--verbose")]
 	public class PropertyDataFlow
 	{
 		public static void Main ()

test/Mono.Linker.Tests.Cases/DynamicDependencies/DynamicDependencyMemberSignatureWildcard.cs

@@ -5,8 +5,9 @@
 
 namespace Mono.Linker.Tests.Cases.DynamicDependencies
 {
-	[LogContains ("IL2037: Mono.Linker.Tests.Cases.DynamicDependencies.DynamicDependencyMemberSignatureWildcard.Dependency(): No members were resolved for '*'.")]
 	[SetupCompileBefore ("library.dll", new[] { "Dependencies/DynamicDependencyMethodInAssemblyLibrary.cs" })]
+	[SetupLinkerArgument ("--verbose")]
+	[LogContains ("IL2037: Mono.Linker.Tests.Cases.DynamicDependencies.DynamicDependencyMemberSignatureWildcard.Dependency(): No members were resolved for '*'.")]
 	public class DynamicDependencyMemberSignatureWildcard
 	{
 		public static void Main ()

test/Mono.Linker.Tests.Cases/DynamicDependencies/DynamicDependencyMethod.cs

@@ -5,6 +5,7 @@
 
 namespace Mono.Linker.Tests.Cases.DynamicDependencies
 {
+	[SetupLinkerArgument ("--verbose")]
 	[LogContains ("IL2037: Mono.Linker.Tests.Cases.DynamicDependencies.DynamicDependencyMethod.B.Broken(): No members were resolved for 'MissingMethod'.")]
 	[LogContains ("IL2037: Mono.Linker.Tests.Cases.DynamicDependencies.DynamicDependencyMethod.B.Broken(): No members were resolved for 'Dependency2``1(``0,System.Int32,System.Object)'.")]
 	[LogContains ("IL2037: Mono.Linker.Tests.Cases.DynamicDependencies.DynamicDependencyMethod.B.Broken(): No members were resolved for '#ctor()'.")]