Implement support for configurable generator options. (dotnet/runtime…

…lab#458)

Commit migrated from dotnet/runtimelab@9649d43

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/DllImportGenerator.cs

@@ -58,7 +58,7 @@ public void Execute(GeneratorExecutionContext context)
                 generatorDiagnostics.ReportTargetFrameworkNotSupported(MinimumSupportedFrameworkVersion);
             }
 
-            var env = new StubEnvironment(context.Compilation, isSupported, targetFrameworkVersion);
+            var env = new StubEnvironment(context.Compilation, isSupported, targetFrameworkVersion, context.AnalyzerConfigOptions.GlobalOptions);
             var generatedDllImports = new StringBuilder();
             foreach (SyntaxReference synRef in synRec.Methods)
             {
@@ -94,7 +94,7 @@ public void Execute(GeneratorExecutionContext context)
 
                 // Process the GeneratedDllImport attribute
                 DllImportStub.GeneratedDllImportData dllImportData;
-                AttributeSyntax dllImportAttr = this.ProcessGeneratedDllImportAttribute(methodSymbolInfo, generatedDllImportAttr, out dllImportData);
+                AttributeSyntax dllImportAttr = this.ProcessGeneratedDllImportAttribute(methodSymbolInfo, generatedDllImportAttr, context.AnalyzerConfigOptions.GlobalOptions.GenerateForwarders(), out dllImportData);
                 Debug.Assert((dllImportAttr is not null) && (dllImportData is not null));
 
                 if (dllImportData!.IsUserDefined.HasFlag(DllImportStub.DllImportMember.BestFitMapping))
@@ -213,6 +213,7 @@ private static bool IsGeneratedDllImportAttribute(AttributeSyntax attrSyntaxMayb
         private AttributeSyntax ProcessGeneratedDllImportAttribute(
             IMethodSymbol method,
             AttributeData attrData,
+            bool generateForwarders,
             out DllImportStub.GeneratedDllImportData dllImportData)
         {
             dllImportData = new DllImportStub.GeneratedDllImportData();
@@ -287,7 +288,9 @@ private AttributeSyntax ProcessGeneratedDllImportAttribute(
 
                 Debug.Assert(expSyntaxMaybe is not null);
 
-                if (PassThroughToDllImportAttribute(namedArg.Key))
+                // If we're generating a forwarder stub, then all parameters on the GenerateDllImport attribute
+                // must also be added to the generated DllImport attribute.
+                if (generateForwarders || PassThroughToDllImportAttribute(namedArg.Key))
                 {
                     // Defer the name equals syntax till we know the value means something. If we created
                     // an expression we know the key value was valid.
@@ -340,9 +343,6 @@ static ExpressionSyntax CreateEnumExpressionSyntax<T>(T value) where T : Enum
 
             static bool PassThroughToDllImportAttribute(string argName)
             {
-#if GENERATE_FORWARDER
-                return true;
-#else
                 // Certain fields on DllImport will prevent inlining. Their functionality should be handled by the
                 // generated source, so the generated DllImport declaration should not include these fields.
                 return argName switch
@@ -355,7 +355,6 @@ static bool PassThroughToDllImportAttribute(string argName)
                     nameof(DllImportStub.GeneratedDllImportData.SetLastError) => false,
                     _ => true
                 };
-#endif
             }
         }
 

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/DllImportGenerator.csproj

@@ -10,9 +10,6 @@
     <LangVersion>Preview</LangVersion>
     <Nullable>enable</Nullable>
     <RootNamespace>Microsoft.Interop</RootNamespace>
-
-    <!-- Uncomment to generate stub code that simply forwards parameters to p/invoke (i.e. no marshalling) -->
-     <!--<DefineConstants>GENERATE_FORWARDER</DefineConstants>--> 
   </PropertyGroup>
 
   <PropertyGroup>
@@ -42,6 +39,7 @@
 
   <ItemGroup>
     <None Include="$(OutputPath)\$(AssemblyName).dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
+    <None Include="Microsoft.Interop.DllImportGenerator.props" Pack="true" PackagePath="build" />
   </ItemGroup>
 
   <ItemGroup>

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/DllImportStub.cs

@@ -6,14 +6,16 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
 using static Microsoft.CodeAnalysis.CSharp.SyntaxFactory;
 
 namespace Microsoft.Interop
 {
     internal record StubEnvironment(
         Compilation Compilation,
         bool SupportedTargetFramework,
-        Version TargetFrameworkVersion);
+        Version TargetFrameworkVersion,
+        AnalyzerConfigOptions Options);
 
     internal class DllImportStub
     {
@@ -177,7 +179,9 @@ public static DllImportStub Create(
             };
 
             var managedRetTypeInfo = retTypeInfo;
-            if (!dllImportData.PreserveSig)
+            // Do not manually handle PreserveSig when generating forwarders.
+            // We want the runtime to handle everything.
+            if (!dllImportData.PreserveSig && !env.Options.GenerateForwarders())
             {
                 // Create type info for native HRESULT return
                 retTypeInfo = TypePositionInfo.CreateForType(env.Compilation.GetSpecialType(SpecialType.System_Int32), NoMarshallingInfo.Instance);
@@ -203,7 +207,7 @@ public static DllImportStub Create(
             }
 
             // Generate stub code
-            var stubGenerator = new StubCodeGenerator(method, dllImportData, paramsTypeInfo, retTypeInfo, diagnostics);
+            var stubGenerator = new StubCodeGenerator(method, dllImportData, paramsTypeInfo, retTypeInfo, diagnostics, env.Options);
             var (code, dllImport) = stubGenerator.GenerateSyntax();
 
             var additionalAttrs = new List<AttributeListSyntax>();

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/Marshalling/MarshallingGenerator.cs

@@ -4,6 +4,7 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
 using static Microsoft.CodeAnalysis.CSharp.SyntaxFactory;
 
 namespace Microsoft.Interop
@@ -109,7 +110,6 @@ internal class MarshallingGenerators
         public static readonly Forwarder Forwarder = new Forwarder();
         public static readonly BlittableMarshaller Blittable = new BlittableMarshaller();
         public static readonly DelegateMarshaller Delegate = new DelegateMarshaller();
-        public static readonly SafeHandleMarshaller SafeHandle = new SafeHandleMarshaller();
         public static readonly HResultExceptionMarshaller HResultException = new HResultExceptionMarshaller();
 
         /// <summary>
@@ -120,11 +120,14 @@ internal class MarshallingGenerators
         /// <returns>A <see cref="IMarshallingGenerator"/> instance.</returns>
         public static IMarshallingGenerator Create(
             TypePositionInfo info,
-            StubCodeContext context)
+            StubCodeContext context,
+            AnalyzerConfigOptions options)
         {
-#if GENERATE_FORWARDER
-            return MarshallingGenerators.Forwarder;
-#else
+            if (options.GenerateForwarders())
+            {
+                return MarshallingGenerators.Forwarder;
+            }
+
             if (info.IsNativeReturnPosition && !info.IsManagedReturnPosition)
             {
                 // Use marshaller for native HRESULT return / exception throwing
@@ -180,7 +183,7 @@ public static IMarshallingGenerator Create(
                     {
                         throw new MarshallingNotSupportedException(info, context);
                     }
-                    return SafeHandle;
+                    return new SafeHandleMarshaller(options);
 
                 // Marshalling in new model.
                 // Must go before the cases that do not explicitly check for marshalling info to support
@@ -204,15 +207,14 @@ public static IMarshallingGenerator Create(
                     return CreateStringMarshaller(info, context);
 
                 case { ManagedType: IArrayTypeSymbol { IsSZArray: true, ElementType: ITypeSymbol elementType } }:
-                    return CreateArrayMarshaller(info, context, elementType);
+                    return CreateArrayMarshaller(info, context, options, elementType);
 
                 case { ManagedType: { SpecialType: SpecialType.System_Void } }:
                     return Forwarder;
 
                 default:
                     throw new MarshallingNotSupportedException(info, context);
             }
-#endif
         }
 
         private static IMarshallingGenerator CreateCharMarshaller(TypePositionInfo info, StubCodeContext context)
@@ -303,7 +305,7 @@ private static IMarshallingGenerator CreateStringMarshaller(TypePositionInfo inf
             throw new MarshallingNotSupportedException(info, context);
         }
 
-        private static ExpressionSyntax GetNumElementsExpressionFromMarshallingInfo(TypePositionInfo info, StubCodeContext context)
+        private static ExpressionSyntax GetNumElementsExpressionFromMarshallingInfo(TypePositionInfo info, StubCodeContext context, AnalyzerConfigOptions options)
         {
             ExpressionSyntax numElementsExpression;
             if (info.MarshallingAttributeInfo is not ArrayMarshalAsInfo marshalAsInfo)
@@ -338,7 +340,7 @@ private static ExpressionSyntax GetNumElementsExpressionFromMarshallingInfo(Type
                 else
                 {
                     var (managed, native) = context.GetIdentifiers(paramIndexInfo);
-                    string identifier = Create(paramIndexInfo, context).UsesNativeIdentifier(paramIndexInfo, context) ? native : managed;
+                    string identifier = Create(paramIndexInfo, context, options).UsesNativeIdentifier(paramIndexInfo, context) ? native : managed;
                     sizeParamIndexExpression = CastExpression(
                             PredefinedType(Token(SyntaxKind.IntKeyword)),
                             IdentifierName(identifier));
@@ -357,7 +359,7 @@ private static ExpressionSyntax GetNumElementsExpressionFromMarshallingInfo(Type
             return numElementsExpression;
         }
 
-        private static IMarshallingGenerator CreateArrayMarshaller(TypePositionInfo info, StubCodeContext context, ITypeSymbol elementType)
+        private static IMarshallingGenerator CreateArrayMarshaller(TypePositionInfo info, StubCodeContext context, AnalyzerConfigOptions options, ITypeSymbol elementType)
         {
             var elementMarshallingInfo = info.MarshallingAttributeInfo switch
             {
@@ -367,12 +369,15 @@ private static IMarshallingGenerator CreateArrayMarshaller(TypePositionInfo info
                 _ => throw new MarshallingNotSupportedException(info, context)
             };
 
-            var elementMarshaller = Create(TypePositionInfo.CreateForType(elementType, elementMarshallingInfo), new ArrayMarshallingCodeContext(StubCodeContext.Stage.Setup, string.Empty, context, false));
+            var elementMarshaller = Create(
+                TypePositionInfo.CreateForType(elementType, elementMarshallingInfo),
+                new ArrayMarshallingCodeContext(StubCodeContext.Stage.Setup, string.Empty, context, false),
+                options);
             ExpressionSyntax numElementsExpression = LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(0));
             if (info.IsManagedReturnPosition || (info.IsByRef && info.RefKind != RefKind.In))
             {
                 // In this case, we need a numElementsExpression supplied from metadata, so we'll calculate it here.
-                numElementsExpression = GetNumElementsExpressionFromMarshallingInfo(info, context);
+                numElementsExpression = GetNumElementsExpressionFromMarshallingInfo(info, context, options);
             }
 
             return elementMarshaller == Blittable

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/Marshalling/SafeHandleMarshaller.cs

@@ -3,13 +3,20 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
 using static Microsoft.CodeAnalysis.CSharp.SyntaxFactory;
 
 namespace Microsoft.Interop
 {
     internal class SafeHandleMarshaller : IMarshallingGenerator
     {
         private static readonly TypeSyntax NativeType = ParseTypeName("global::System.IntPtr");
+        private readonly AnalyzerConfigOptions options;
+
+        public SafeHandleMarshaller(AnalyzerConfigOptions options)
+        {
+            this.options = options;
+        }
 
         public TypeSyntax AsNativeType(TypePositionInfo info)
         {
@@ -83,7 +90,7 @@ public IEnumerable<StatementSyntax> Generate(TypePositionInfo info, StubCodeCont
                                 IdentifierName(managedIdentifier),
                                 InvocationExpression(
                                     MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression,
-                                        ParseName(TypeNames.System_Runtime_InteropServices_MarshalEx),
+                                        ParseName(TypeNames.MarshalEx(options)),
                                         GenericName(Identifier("CreateSafeHandle"),
                                             TypeArgumentList(SingletonSeparatedList(info.ManagedType.AsTypeSyntax())))),
                                     ArgumentList())));
@@ -101,7 +108,7 @@ public IEnumerable<StatementSyntax> Generate(TypePositionInfo info, StubCodeCont
                                     .WithInitializer(EqualsValueClause(
                                         InvocationExpression(
                                             MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression,
-                                                ParseName(TypeNames.System_Runtime_InteropServices_MarshalEx),
+                                                ParseName(TypeNames.MarshalEx(options)),
                                                 GenericName(Identifier("CreateSafeHandle"),
                                                     TypeArgumentList(SingletonSeparatedList(info.ManagedType.AsTypeSyntax())))),
                                             ArgumentList()))))));
@@ -160,7 +167,7 @@ public IEnumerable<StatementSyntax> Generate(TypePositionInfo info, StubCodeCont
                     StatementSyntax unmarshalStatement = ExpressionStatement(
                         InvocationExpression(
                             MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression,
-                                ParseTypeName(TypeNames.System_Runtime_InteropServices_MarshalEx),
+                                ParseTypeName(TypeNames.MarshalEx(options)),
                                 IdentifierName("SetHandle")),
                             ArgumentList(SeparatedList(
                                 new []

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/Microsoft.Interop.DllImportGenerator.props

@@ -0,0 +1,19 @@
+<Project>
+  <!--
+    Define all of the configuration options supported for the DllImportGenerator.
+    To use, set an MSBuild property with the name of the option to `true`.
+    See OptionsHelper.cs for more information on usage.
+  -->
+  <ItemGroup>
+      <!--
+        Use the System.Runtime.InteropServices.Marshal type instead of
+        the System.Runtime.InteropServices.MarshalEx type when emitting code.
+      -->
+      <CompilerVisibleProperty Include="DllImportGenerator_UseMarshalType" />
+      <!--
+        Generate a stub that forwards to a runtime implemented P/Invoke stub instead
+        of generating a stub that handles all of the marshalling.
+      -->
+      <CompilerVisibleProperty Include="DllImportGenerator_GenerateForwarders" />
+  </ItemGroup>
+</Project>

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/OptionsHelper.cs

@@ -0,0 +1,26 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace Microsoft.Interop
+{
+    public static class OptionsHelper
+    {
+        public const string UseMarshalTypeOption = "build_property.DllImportGenerator_UseMarshalType";
+        public const string GenerateForwardersOption = "build_property.DllImportGenerator_GenerateForwarders";
+
+        private static bool GetBoolOption(this AnalyzerConfigOptions options, string key)
+        {
+            return options.TryGetValue(key, out string? value)
+                && bool.TryParse(value, out bool result)
+                && result;
+        }
+
+        internal static bool UseMarshalType(this AnalyzerConfigOptions options) => options.GetBoolOption(UseMarshalTypeOption);
+
+        internal static bool GenerateForwarders(this AnalyzerConfigOptions options) => options.GetBoolOption(GenerateForwardersOption);
+    }
+}