BridgeJS: Support generic exports, callbacks, and initializers

Author: krodak

Plugins/BridgeJS/Sources/BridgeJSCore/ClosureCodegen.swift

@@ -47,6 +47,7 @@ public struct ClosureCodegen {
         for (index, paramType) in signature.parameters.enumerated() {
             try builder.lowerParameter(param: Parameter(label: nil, name: "param\(index)", type: paramType))
         }
+        builder.appendTypeIDParameters(signature.genericParameterNames)
 
         // Generate the call and return value lifting
         try builder.call()
@@ -69,7 +70,14 @@ public struct ClosureCodegen {
         let helperEnumDeclPrinter = CodeFragmentPrinter()
         helperEnumDeclPrinter.write("private enum \(helperName) {")
         helperEnumDeclPrinter.indent {
-            helperEnumDeclPrinter.write("static func bridgeJSLift(_ callbackId: Int32) -> \(swiftClosureType) {")
+            let genericNames = signature.genericParameterNames
+            let genericClause =
+                genericNames.isEmpty
+                ? "" : "<\(genericNames.map { "\($0): BridgedSwiftGenericBridgeable" }.joined(separator: ", "))>"
+            let parameters = (["_ callbackId: Int32"] + genericNames.map { "_: \($0).Type" }).joined(separator: ", ")
+            helperEnumDeclPrinter.write(
+                "static func bridgeJSLift\(genericClause)(\(parameters)) -> \(swiftClosureType) {"
+            )
             helperEnumDeclPrinter.indent {
                 helperEnumDeclPrinter.write("let callback = JSObject.bridgeJSLiftParameter(callbackId)")
                 let parameters: String
@@ -112,6 +120,10 @@ public struct ClosureCodegen {
 
         let helperEnumDecl: DeclSyntax = "\(raw: helperEnumDeclPrinter.lines.joined(separator: "\n"))"
 
+        if !signature.genericParameterNames.isEmpty {
+            return [externDecl, helperEnumDecl]
+        }
+
         let accessModifier = accessLevel.modifierKeyword.map { "\($0) " } ?? ""
         let declaration = signature.sendingParameters ? "static func sending" : "init"
         let returnClause = signature.sendingParameters ? " -> Self" : ""
@@ -164,10 +176,38 @@ public struct ClosureCodegen {
         guard !signatureAccessLevels.isEmpty else { return nil }
 
         var decls: [DeclSyntax] = []
+        var asyncGenericResults = Set<BridgeType>()
         for signature in signatureAccessLevels.keys.sorted(by: { $0.mangleName < $1.mangleName }) {
             let accessLevel = signatureAccessLevels[signature] ?? .internal
             decls.append(contentsOf: try renderClosureHelpers(signature, accessLevel: accessLevel))
-            decls.append(try renderClosureInvokeHandler(signature))
+            if signature.genericParameterNames.isEmpty {
+                decls.append(try renderClosureInvokeHandler(signature))
+            }
+            let returnType = signature.returnType
+            if signature.isAsync, returnType.usesGenericParameter, asyncGenericResults.insert(returnType).inserted {
+                let parameter = Parameter(label: nil, name: "value", type: .jsValue)
+                let effects = Effects(isAsync: false, isThrows: true)
+                let builder = try ImportTS.CallJSEmission(
+                    moduleName: "bjs",
+                    abiName: "async_callback_result_\(signature.moduleName)_\(returnType.mangleTypeName)",
+                    effects: effects,
+                    returnType: returnType
+                )
+                try builder.lowerParameter(param: parameter)
+                builder.appendTypeIDParameters(returnType.referencedGenericNames)
+                try builder.call()
+                try builder.liftReturnValue()
+                decls.append(builder.renderImportDecl())
+                decls.append(
+                    builder.renderThunkDecl(
+                        name: "_bjs_async_result_\(returnType.mangleTypeName)",
+                        parameters: [parameter],
+                        returnType: returnType,
+                        effects: effects,
+                        genericParameters: returnType.referencedGenericNames.map { GenericParameter(name: $0) }
+                    )
+                )
+            }
         }
 
         return withSpan("Format Closure Glue") {

Plugins/BridgeJS/Sources/BridgeJSCore/ExportSwift.swift

@@ -7,6 +7,7 @@ public struct ExternalModuleIndex {
     public struct ExternalType: Equatable {
         public let moduleName: String
         public let bridgeType: BridgeType
+        public var isGenericBridgeableProtocol = false
     }
 
     public enum LookupResult: Equatable {
@@ -31,8 +32,12 @@ public struct ExternalModuleIndex {
             guard let exported = skeleton.exported else { continue }
             var moduleEntries = entriesByModule[moduleName] ?? [:]
 
-            func register(dotPath: String, bridgeType: BridgeType) {
-                let externalType = ExternalType(moduleName: moduleName, bridgeType: bridgeType)
+            func register(dotPath: String, bridgeType: BridgeType, isGenericBridgeableProtocol: Bool = false) {
+                let externalType = ExternalType(
+                    moduleName: moduleName,
+                    bridgeType: bridgeType,
+                    isGenericBridgeableProtocol: isGenericBridgeableProtocol
+                )
                 if moduleEntries[dotPath] == nil {
                     moduleEntries[dotPath] = externalType
                     entriesByDotPath[dotPath, default: []].append(externalType)
@@ -61,7 +66,11 @@ public struct ExternalModuleIndex {
                 register(dotPath: enumDef.swiftCallName, bridgeType: bridgeType)
             }
             for proto in exported.protocols {
-                register(dotPath: proto.name, bridgeType: .swiftProtocol(proto.name))
+                register(
+                    dotPath: proto.name,
+                    bridgeType: .swiftProtocol(proto.name),
+                    isGenericBridgeableProtocol: proto.isGenericBridgeable == true
+                )
             }
             for alias in exported.aliases {
                 register(

Plugins/BridgeJS/Sources/BridgeJSCore/ExternalModuleIndex.swift

@@ -346,7 +346,7 @@ public struct ImportTS {
                     "\(tryKeyword) await _bjs_awaitPromise(\(resolveFactory), \(rejectFactory)) { resolveRef, rejectRef in"
                 )
             } else {
-                let resolveSwiftType = returnType.closureSwiftType
+                let resolveSwiftType = returnType.usesGenericParameter ? "JSValue" : returnType.closureSwiftType
                 let resolveFactory =
                     "makeResolveClosure: { JSTypedClosure<(sending \(resolveSwiftType)) -> Void>.sending($0) }"
                 body.write(
@@ -359,7 +359,11 @@ public struct ImportTS {
             body.write("}")
 
             if returnType != .void {
-                body.write("return resolved")
+                if returnType.usesGenericParameter {
+                    body.write("return \(tryKeyword) _bjs_async_result_\(returnType.mangleTypeName)(resolved)")
+                } else {
+                    body.write("return resolved")
+                }
             }
         }
 
@@ -381,7 +385,7 @@ public struct ImportTS {
             parameters: [Parameter],
             returnType: BridgeType,
             effects: Effects,
-            genericParameters: [String] = []
+            genericParameters: [GenericParameter] = []
         ) -> DeclSyntax {
             let printer = CodeFragmentPrinter()
             let signature = SwiftSignatureBuilder.buildFunctionSignature(
@@ -393,7 +397,11 @@ public struct ImportTS {
             let genericClause =
                 genericParameters.isEmpty
                 ? ""
-                : "<" + genericParameters.map { "\($0): BridgedSwiftGenericBridgeable" }.joined(separator: ", ")
+                : "<"
+                    + genericParameters.map { genericParameter in
+                        let constraints = ["BridgedSwiftGenericBridgeable"] + genericParameter.constraints
+                        return "\(genericParameter.name): \(constraints.joined(separator: " & "))"
+                    }.joined(separator: ", ")
                     + ">"
             printer.write("func \(name.backtickIfNeeded())\(genericClause)\(signature) {")
             printer.indent {
@@ -465,7 +473,7 @@ public struct ImportTS {
                 parameters: function.parameters,
                 returnType: function.returnType,
                 effects: function.effects,
-                genericParameters: function.genericParameterNames
+                genericParameters: function.genericParameters ?? []
             )
             .with(\.leadingTrivia, Self.renderDocumentation(documentation: function.documentation))
         ]
@@ -496,7 +504,7 @@ public struct ImportTS {
                     parameters: [selfParameter] + method.parameters,
                     returnType: method.returnType,
                     effects: method.effects,
-                    genericParameters: method.genericParameterNames
+                    genericParameters: method.genericParameters ?? []
                 )
             ]
         }
@@ -522,7 +530,7 @@ public struct ImportTS {
                     parameters: method.parameters,
                     returnType: method.returnType,
                     effects: method.effects,
-                    genericParameters: method.genericParameterNames
+                    genericParameters: method.genericParameters ?? []
                 )
             ]
         }
@@ -548,7 +556,7 @@ public struct ImportTS {
                     parameters: constructor.parameters,
                     returnType: .jsObject(nil),
                     effects: effects,
-                    genericParameters: constructor.genericParameterNames
+                    genericParameters: constructor.genericParameters ?? []
                 )
             ]
         }