Add forwarding support for WasmLinkage on LibraryImport (dotnet#109234)

Author: jkoritzinsky

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

@@ -109,7 +109,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             context.RegisterConcatenatedSyntaxOutputs(generateSingleStub.Select((data, ct) => data.Item1), "LibraryImports.g.cs");
         }
 
-        private static List<AttributeSyntax> GenerateSyntaxForForwardedAttributes(AttributeData? suppressGCTransitionAttribute, AttributeData? unmanagedCallConvAttribute, AttributeData? defaultDllImportSearchPathsAttribute)
+        private static List<AttributeSyntax> GenerateSyntaxForForwardedAttributes(AttributeData? suppressGCTransitionAttribute, AttributeData? unmanagedCallConvAttribute, AttributeData? defaultDllImportSearchPathsAttribute, AttributeData? wasmImportLinkageAttribute)
         {
             const string CallConvsField = "CallConvs";
             // Manually rehydrate the forwarded attributes with fully qualified types so we don't have to worry about any using directives.
@@ -153,6 +153,10 @@ private static List<AttributeSyntax> GenerateSyntaxForForwardedAttributes(Attrib
                                 LiteralExpression(SyntaxKind.NumericLiteralExpression,
                                     Literal((int)defaultDllImportSearchPathsAttribute.ConstructorArguments[0].Value!))))));
             }
+            if (wasmImportLinkageAttribute is not null)
+            {
+                attributes.Add(Attribute(NameSyntaxes.WasmImportLinkageAttribute));
+            }
             return attributes;
         }
 
@@ -223,12 +227,14 @@ private static IncrementalStubGenerationContext CalculateStubInformation(
             INamedTypeSymbol? suppressGCTransitionAttrType = environment.SuppressGCTransitionAttrType;
             INamedTypeSymbol? unmanagedCallConvAttrType = environment.UnmanagedCallConvAttrType;
             INamedTypeSymbol? defaultDllImportSearchPathsAttrType = environment.DefaultDllImportSearchPathsAttrType;
+            INamedTypeSymbol? wasmImportLinkageAttrType = environment.WasmImportLinkageAttrType;
             // Get any attributes of interest on the method
             AttributeData? generatedDllImportAttr = null;
             AttributeData? lcidConversionAttr = null;
             AttributeData? suppressGCTransitionAttribute = null;
             AttributeData? unmanagedCallConvAttribute = null;
             AttributeData? defaultDllImportSearchPathsAttribute = null;
+            AttributeData? wasmImportLinkageAttribute = null;
             foreach (AttributeData attr in symbol.GetAttributes())
             {
                 if (attr.AttributeClass is not null
@@ -252,6 +258,10 @@ private static IncrementalStubGenerationContext CalculateStubInformation(
                 {
                     defaultDllImportSearchPathsAttribute = attr;
                 }
+                else if (wasmImportLinkageAttrType is not null && SymbolEqualityComparer.Default.Equals(attr.AttributeClass, wasmImportLinkageAttrType))
+                {
+                    wasmImportLinkageAttribute = attr;
+                }
             }
 
             Debug.Assert(generatedDllImportAttr is not null);
@@ -299,7 +309,7 @@ private static IncrementalStubGenerationContext CalculateStubInformation(
 
             var methodSyntaxTemplate = new ContainingSyntax(originalSyntax.Modifiers, SyntaxKind.MethodDeclaration, originalSyntax.Identifier, originalSyntax.TypeParameterList);
 
-            List<AttributeSyntax> additionalAttributes = GenerateSyntaxForForwardedAttributes(suppressGCTransitionAttribute, unmanagedCallConvAttribute, defaultDllImportSearchPathsAttribute);
+            List<AttributeSyntax> additionalAttributes = GenerateSyntaxForForwardedAttributes(suppressGCTransitionAttribute, unmanagedCallConvAttribute, defaultDllImportSearchPathsAttribute, wasmImportLinkageAttribute);
             return new IncrementalStubGenerationContext(
                 signatureContext,
                 containingTypeContext,

src/libraries/System.Runtime.InteropServices/gen/Microsoft.Interop.SourceGeneration/StubEnvironment.cs

@@ -73,5 +73,19 @@ public INamedTypeSymbol? DefaultDllImportSearchPathsAttrType
                 return _defaultDllImportSearchPathsAttrType.Value;
             }
         }
+
+        private Optional<INamedTypeSymbol?> _wasmImportLinkageAttrType;
+        public INamedTypeSymbol? WasmImportLinkageAttrType
+        {
+            get
+            {
+                if (_wasmImportLinkageAttrType.HasValue)
+                {
+                    return _wasmImportLinkageAttrType.Value;
+                }
+                _wasmImportLinkageAttrType = new Optional<INamedTypeSymbol?>(Compilation.GetTypeByMetadataName(TypeNames.WasmImportLinkageAttribute));
+                return _wasmImportLinkageAttrType.Value;
+            }
+        }
     }
 }

src/libraries/System.Runtime.InteropServices/gen/Microsoft.Interop.SourceGeneration/TypeNames.cs

@@ -39,6 +39,9 @@ public static class NameSyntaxes
 
         private static NameSyntax? _UnmanagedCallersOnlyAttribute;
         public static NameSyntax UnmanagedCallersOnlyAttribute => _UnmanagedCallersOnlyAttribute ??= ParseName(TypeNames.GlobalAlias + TypeNames.UnmanagedCallersOnlyAttribute);
+
+        private static NameSyntax? _WasmImportLinkageAttribute;
+        public static NameSyntax WasmImportLinkageAttribute => _WasmImportLinkageAttribute ??= ParseName(TypeNames.GlobalAlias + TypeNames.WasmImportLinkageAttribute);
     }
 
     public static class TypeSyntaxes
@@ -312,5 +315,6 @@ public static string MarshalEx(InteropGenerationOptions options)
         public const string CallConvMemberFunctionName = "System.Runtime.CompilerServices.CallConvMemberFunction";
         public const string Nint = "nint";
         public const string ComVariantMarshaller = "System.Runtime.InteropServices.Marshalling.ComVariantMarshaller";
+        public const string WasmImportLinkageAttribute = "System.Runtime.InteropServices.WasmImportLinkageAttribute";
     }
 }

src/libraries/System.Runtime.InteropServices/tests/LibraryImportGenerator.UnitTests/AttributeForwarding.cs

@@ -21,6 +21,7 @@ public class AttributeForwarding
         [Theory]
         [InlineData("SuppressGCTransition", "System.Runtime.InteropServices.SuppressGCTransitionAttribute")]
         [InlineData("UnmanagedCallConv", "System.Runtime.InteropServices.UnmanagedCallConvAttribute")]
+        [InlineData("WasmImportLinkage", "System.Runtime.InteropServices.WasmImportLinkageAttribute")]
         public async Task KnownParameterlessAttribute(string attributeSourceName, string attributeMetadataName)
         {
             string source = $$"""