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ExportSwift.swift
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1787 lines (1620 loc) · 69.7 KB
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import SwiftBasicFormat
import SwiftSyntax
import SwiftSyntaxBuilder
#if canImport(BridgeJSSkeleton)
import BridgeJSSkeleton
#endif
#if canImport(BridgeJSUtilities)
import BridgeJSUtilities
#endif
/// Exports Swift functions and classes to JavaScript
///
/// This class processes Swift source files to find declarations marked with `@JS`
/// and generates:
/// 1. Swift glue code to call the Swift functions from JavaScript
/// 2. Skeleton files that define the structure of the exported APIs
///
/// The generated skeletons will be used by ``BridgeJSLink`` to generate
/// JavaScript glue code and TypeScript definitions.
public class ExportSwift {
let progress: ProgressReporting
let moduleName: String
private let exposeToGlobal: Bool
private var skeleton: ExportedSkeleton
private var sourceFiles: [(sourceFile: SourceFileSyntax, inputFilePath: String)] = []
public init(progress: ProgressReporting, moduleName: String, skeleton: ExportedSkeleton) {
self.progress = progress
self.moduleName = moduleName
self.exposeToGlobal = skeleton.exposeToGlobal
self.skeleton = skeleton
}
/// Finalizes the export process and generates the bridge code
///
/// - Parameters:
/// - exposeToGlobal: Whether to expose exported APIs to the global namespace (default: false)
/// - Returns: A tuple containing the generated Swift code and a skeleton
/// describing the exported APIs
public func finalize() throws -> String? {
guard let outputSwift = try renderSwiftGlue() else {
return nil
}
return outputSwift
}
func renderSwiftGlue() throws -> String? {
var decls: [DeclSyntax] = []
try withSpan("Render Protocols") { [self] in
let protocolCodegen = ProtocolCodegen()
for proto in skeleton.protocols {
decls.append(contentsOf: try protocolCodegen.renderProtocolWrapper(proto, moduleName: moduleName))
}
}
try withSpan("Render Enums") { [self] in
let enumCodegen = EnumCodegen()
for enumDef in skeleton.enums {
if let enumHelpers = enumCodegen.renderEnumHelpers(enumDef) {
decls.append(enumHelpers)
}
for staticMethod in enumDef.staticMethods {
decls.append(try renderSingleExportedFunction(function: staticMethod))
}
for staticProperty in enumDef.staticProperties {
decls.append(
contentsOf: try renderSingleExportedProperty(
property: staticProperty,
context: .enumStatic(enumDef: enumDef)
)
)
}
}
}
try withSpan("Render Structs") { [self] in
let structCodegen = StructCodegen()
for structDef in skeleton.structs {
decls.append(contentsOf: structCodegen.renderStructHelpers(structDef))
decls.append(contentsOf: try renderSingleExportedStruct(struct: structDef))
}
for function in skeleton.functions {
decls.append(try renderSingleExportedFunction(function: function))
}
for klass in skeleton.classes {
decls.append(contentsOf: try renderSingleExportedClass(klass: klass))
}
}
return withSpan("Format Export Glue") {
return decls.map { $0.description }.joined(separator: "\n\n")
}
}
class ExportedThunkBuilder {
var body: [CodeBlockItemSyntax] = []
var liftedParameterExprs: [ExprSyntax] = []
var parameters: [Parameter] = []
var abiParameterSignatures: [(name: String, type: WasmCoreType)] = []
var abiReturnType: WasmCoreType?
var externDecls: [DeclSyntax] = []
let effects: Effects
init(effects: Effects) {
self.effects = effects
}
private func append(_ item: CodeBlockItemSyntax) {
var item = item
// Add a newline for items after the first one
if !self.body.isEmpty {
item = item.with(\.leadingTrivia, .newline)
}
self.body.append(item)
}
func liftParameter(param: Parameter) throws {
parameters.append(param)
let liftingInfo = try param.type.liftParameterInfo()
let argumentsToLift: [String]
if liftingInfo.parameters.count == 1 {
argumentsToLift = [param.name]
} else {
argumentsToLift = liftingInfo.parameters.map { (name, _) in param.name + name.capitalizedFirstLetter }
}
let typeNameForIntrinsic: String
let liftingExpr: ExprSyntax
switch param.type {
case .closure(let signature, _):
typeNameForIntrinsic = param.type.swiftType
liftingExpr = ExprSyntax("_BJS_Closure_\(raw: signature.mangleName).bridgeJSLift(\(raw: param.name))")
case .swiftStruct(let structName):
typeNameForIntrinsic = structName
liftingExpr = ExprSyntax("\(raw: structName).bridgeJSLiftParameter()")
case .array:
typeNameForIntrinsic = param.type.swiftType
liftingExpr = StackCodegen().liftExpression(for: param.type)
case .nullable(let wrappedType, let kind):
let optionalSwiftType: String
if case .null = kind {
optionalSwiftType = "Optional"
} else {
optionalSwiftType = "JSUndefinedOr"
}
typeNameForIntrinsic = "\(optionalSwiftType)<\(wrappedType.swiftType)>"
liftingExpr = ExprSyntax(
"\(raw: typeNameForIntrinsic).bridgeJSLiftParameter(\(raw: argumentsToLift.joined(separator: ", ")))"
)
default:
typeNameForIntrinsic = param.type.swiftType
liftingExpr = ExprSyntax(
"\(raw: typeNameForIntrinsic).bridgeJSLiftParameter(\(raw: argumentsToLift.joined(separator: ", ")))"
)
}
liftedParameterExprs.append(liftingExpr)
for (name, type) in zip(argumentsToLift, liftingInfo.parameters.map { $0.type }) {
abiParameterSignatures.append((name, type))
}
}
private func protocolCastSuffix(for returnType: BridgeType) -> (prefix: String, suffix: String) {
switch returnType {
case .swiftProtocol:
return ("", " as! \(returnType.swiftType)")
case .nullable(let wrappedType, _):
if case .swiftProtocol = wrappedType {
return ("(", ").flatMap { $0 as? \(wrappedType.swiftType) }")
}
return ("", "")
default:
return ("", "")
}
}
private func removeFirstLiftedParameter() -> (parameter: Parameter, expr: ExprSyntax) {
let parameter = parameters.removeFirst()
let expr = liftedParameterExprs.removeFirst()
return (parameter, expr)
}
private func renderCallStatement(callee: ExprSyntax, returnType: BridgeType) -> CodeBlockItemSyntax {
let labeledParams = zip(parameters, liftedParameterExprs).map { param, expr in
LabeledExprSyntax(label: param.label, expression: expr)
}
var callExpr: ExprSyntax =
"\(raw: callee)(\(raw: labeledParams.map { $0.description }.joined(separator: ", ")))"
if effects.isAsync {
callExpr = ExprSyntax(
AwaitExprSyntax(awaitKeyword: .keyword(.await).with(\.trailingTrivia, .space), expression: callExpr)
)
}
if effects.isThrows {
callExpr = ExprSyntax(
TryExprSyntax(
tryKeyword: .keyword(.try).with(\.trailingTrivia, .space),
expression: callExpr
)
)
}
if effects.isAsync, returnType != .void {
return CodeBlockItemSyntax(item: .init(StmtSyntax("return \(raw: callExpr).jsValue")))
}
if returnType == .void {
return CodeBlockItemSyntax(item: .init(ExpressionStmtSyntax(expression: callExpr)))
} else {
let (prefix, suffix) = protocolCastSuffix(for: returnType)
return CodeBlockItemSyntax(
item: .init(DeclSyntax("let ret = \(raw: prefix)\(raw: callExpr)\(raw: suffix)"))
)
}
}
func call(name: String, returnType: BridgeType) {
generateParameterLifting()
let item = renderCallStatement(callee: "\(raw: name)", returnType: returnType)
append(item)
}
func callStaticProperty(name: String, returnType: BridgeType) {
if returnType == .void {
append("\(raw: name)")
} else {
let (prefix, suffix) = protocolCastSuffix(for: returnType)
append("let ret = \(raw: prefix)\(raw: name)\(raw: suffix)")
}
}
func callMethod(methodName: String, returnType: BridgeType) {
let (_, selfExpr) = removeFirstLiftedParameter()
generateParameterLifting()
let item = renderCallStatement(
callee: "\(raw: selfExpr).\(raw: methodName)",
returnType: returnType
)
append(item)
}
/// Generates intermediate variables for stack-using parameters if needed for LIFO compatibility
private func generateParameterLifting() {
let stackParamIndices = parameters.enumerated().compactMap { index, param -> Int? in
switch param.type {
case .swiftStruct, .nullable(.swiftStruct, _),
.associatedValueEnum, .nullable(.associatedValueEnum, _),
.array:
return index
default:
return nil
}
}
guard stackParamIndices.count > 1 else { return }
for index in stackParamIndices.reversed() {
let param = parameters[index]
let expr = liftedParameterExprs[index]
let varName = "_tmp_\(param.name)"
append("let \(raw: varName) = \(expr)")
liftedParameterExprs[index] = ExprSyntax(DeclReferenceExprSyntax(baseName: .identifier(varName)))
}
}
func callPropertyGetter(propertyName: String, returnType: BridgeType) {
let (_, selfExpr) = removeFirstLiftedParameter()
if returnType == .void {
append("\(raw: selfExpr).\(raw: propertyName)")
} else {
let (prefix, suffix) = protocolCastSuffix(for: returnType)
append("let ret = \(raw: prefix)\(raw: selfExpr).\(raw: propertyName)\(raw: suffix)")
}
}
func callPropertySetter(propertyName: String) {
let (_, selfExpr) = removeFirstLiftedParameter()
let (_, newValueExpr) = removeFirstLiftedParameter()
append("\(raw: selfExpr).\(raw: propertyName) = \(raw: newValueExpr)")
}
func callStaticPropertySetter(klassName: String, propertyName: String) {
let (_, newValueExpr) = removeFirstLiftedParameter()
append("\(raw: klassName).\(raw: propertyName) = \(raw: newValueExpr)")
}
func lowerReturnValue(returnType: BridgeType) throws {
if effects.isAsync {
// Async functions always return a Promise, which is a JSObject
try _lowerReturnValue(returnType: .jsObject(nil))
} else {
try _lowerReturnValue(returnType: returnType)
}
}
private func _lowerReturnValue(returnType: BridgeType) throws {
let loweringInfo = try returnType.loweringReturnInfo()
abiReturnType = loweringInfo.returnType
if returnType == .void {
return
}
if effects.isAsync {
// The return value of async function (T of `(...) async -> T`) is
// handled by the JSPromise.async, so we don't need to do anything here.
return
}
switch returnType {
case .closure(_, useJSTypedClosure: false):
append("return JSTypedClosure(ret).bridgeJSLowerReturn()")
case .array, .nullable(.array, _):
let stackCodegen = StackCodegen()
for stmt in stackCodegen.lowerStatements(for: returnType, accessor: "ret", varPrefix: "ret") {
append(stmt)
}
default:
append("return ret.bridgeJSLowerReturn()")
}
}
func render(abiName: String) -> DeclSyntax {
let body: CodeBlockItemListSyntax
if effects.isAsync {
body = """
let ret = JSPromise.async {
\(CodeBlockItemListSyntax(self.body))
}.jsObject
return ret.bridgeJSLowerReturn()
"""
} else if effects.isThrows {
body = """
do {
\(CodeBlockItemListSyntax(self.body))
} catch let error {
if let error = error.thrownValue.object {
withExtendedLifetime(error) {
_swift_js_throw(Int32(bitPattern: $0.id))
}
} else {
let jsError = JSError(message: String(describing: error))
withExtendedLifetime(jsError.jsObject) {
_swift_js_throw(Int32(bitPattern: $0.id))
}
}
\(raw: returnPlaceholderStmt())
}
"""
} else {
body = CodeBlockItemListSyntax(self.body)
}
// Build function signature using SwiftSignatureBuilder
let signature = SwiftSignatureBuilder.buildABIFunctionSignature(
abiParameters: abiParameterSignatures,
returnType: abiReturnType
)
// Build function declaration using helper function
let funcDecl = SwiftCodePattern.buildExposedFunctionDecl(
abiName: abiName,
signature: signature
) { printer in
printer.write(multilineString: body.description)
}
return DeclSyntax(funcDecl)
}
private func returnPlaceholderStmt() -> String {
return abiReturnType?.swiftReturnPlaceholderStmt ?? "return"
}
}
/// Context for property rendering that determines call behavior and ABI generation
private enum PropertyRenderingContext {
case enumStatic(enumDef: ExportedEnum)
case classStatic(klass: ExportedClass)
case classInstance(klass: ExportedClass)
case structStatic(structDef: ExportedStruct)
var isStatic: Bool {
switch self {
case .enumStatic, .classStatic, .structStatic:
return true
case .classInstance:
return false
}
}
var className: String {
switch self {
case .enumStatic(let enumDef):
return enumDef.name
case .classStatic(let klass), .classInstance(let klass):
return klass.name
case .structStatic(let structDef):
return structDef.name
}
}
func callName(for property: ExportedProperty) -> String {
switch self {
case .enumStatic(let enumDef):
return property.callName(prefix: enumDef.swiftCallName)
case .classStatic, .classInstance:
return property.callName()
case .structStatic(let structDef):
return property.callName(prefix: structDef.swiftCallName)
}
}
}
/// Renders getter and setter Swift thunk code for a property in any context
/// This unified function eliminates duplication between enum static, class static, and class instance property rendering
private func renderSingleExportedProperty(
property: ExportedProperty,
context: PropertyRenderingContext
) throws -> [DeclSyntax] {
var decls: [DeclSyntax] = []
let callName = context.callName(for: property)
let className = context.className
let isStatic = context.isStatic
let getterBuilder = ExportedThunkBuilder(effects: Effects(isAsync: false, isThrows: false, isStatic: isStatic))
if !isStatic {
try getterBuilder.liftParameter(
param: Parameter(label: nil, name: "_self", type: .swiftHeapObject(className))
)
}
if isStatic {
getterBuilder.callStaticProperty(name: callName, returnType: property.type)
} else {
getterBuilder.callPropertyGetter(propertyName: callName, returnType: property.type)
}
try getterBuilder.lowerReturnValue(returnType: property.type)
decls.append(getterBuilder.render(abiName: property.getterAbiName(className: className)))
// Generate property setter if not readonly
if !property.isReadonly {
let setterBuilder = ExportedThunkBuilder(
effects: Effects(isAsync: false, isThrows: false, isStatic: isStatic)
)
// Lift parameters based on property type
if !isStatic {
// Instance properties need _self parameter
try setterBuilder.liftParameter(
param: Parameter(label: nil, name: "_self", type: .swiftHeapObject(className))
)
}
try setterBuilder.liftParameter(
param: Parameter(label: "value", name: "value", type: property.type)
)
if isStatic {
let klassName = callName.components(separatedBy: ".").dropLast().joined(separator: ".")
setterBuilder.callStaticPropertySetter(klassName: klassName, propertyName: property.name)
} else {
setterBuilder.callPropertySetter(propertyName: callName)
}
try setterBuilder.lowerReturnValue(returnType: .void)
decls.append(setterBuilder.render(abiName: property.setterAbiName(className: className)))
}
return decls
}
func renderSingleExportedFunction(function: ExportedFunction) throws -> DeclSyntax {
let builder = ExportedThunkBuilder(effects: function.effects)
for param in function.parameters {
try builder.liftParameter(param: param)
}
if function.effects.isStatic, let staticContext = function.staticContext {
let callName = "\(staticContextBaseName(staticContext)).\(function.name)"
builder.call(name: callName, returnType: function.returnType)
} else {
builder.call(name: function.name, returnType: function.returnType)
}
try builder.lowerReturnValue(returnType: function.returnType)
return builder.render(abiName: function.abiName)
}
private func staticContextBaseName(_ staticContext: StaticContext) -> String {
switch staticContext {
case .className(let baseName), .enumName(let baseName), .structName(let baseName),
.namespaceEnum(let baseName):
return baseName
}
}
private func renderSingleExportedConstructor(
constructor: ExportedConstructor,
callName: String,
returnType: BridgeType
) throws -> DeclSyntax {
let builder = ExportedThunkBuilder(effects: constructor.effects)
for param in constructor.parameters {
try builder.liftParameter(param: param)
}
builder.call(name: callName, returnType: returnType)
try builder.lowerReturnValue(returnType: returnType)
return builder.render(abiName: constructor.abiName)
}
private func renderSingleExportedMethod(
method: ExportedFunction,
ownerTypeName: String,
instanceSelfType: BridgeType
) throws -> DeclSyntax {
let builder = ExportedThunkBuilder(effects: method.effects)
if !method.effects.isStatic {
try builder.liftParameter(param: Parameter(label: nil, name: "_self", type: instanceSelfType))
}
for param in method.parameters {
try builder.liftParameter(param: param)
}
if method.effects.isStatic {
builder.call(name: "\(ownerTypeName).\(method.name)", returnType: method.returnType)
} else {
builder.callMethod(methodName: method.name, returnType: method.returnType)
}
try builder.lowerReturnValue(returnType: method.returnType)
return builder.render(abiName: method.abiName)
}
func renderSingleExportedStruct(struct structDef: ExportedStruct) throws -> [DeclSyntax] {
var decls: [DeclSyntax] = []
if let constructor = structDef.constructor {
decls.append(
try renderSingleExportedConstructor(
constructor: constructor,
callName: structDef.swiftCallName,
returnType: .swiftStruct(structDef.swiftCallName)
)
)
}
for property in structDef.properties where property.isStatic {
decls.append(
contentsOf: try renderSingleExportedProperty(
property: property,
context: .structStatic(structDef: structDef)
)
)
}
for method in structDef.methods {
decls.append(
try renderSingleExportedMethod(
method: method,
ownerTypeName: structDef.swiftCallName,
instanceSelfType: .swiftStruct(structDef.swiftCallName)
)
)
}
return decls
}
/// # Example
///
/// Given the following Swift code:
///
/// ```swift
/// @JS class Greeter {
/// var name: String
///
/// @JS init(name: String) {
/// self.name = name
/// }
///
/// @JS func greet() -> String {
/// return "Hello, \(name)!"
/// }
/// }
/// ```
///
/// The following Swift glue code will be generated:
///
/// ```swift
/// @_expose(wasm, "bjs_Greeter_init")
/// @_cdecl("bjs_Greeter_init")
/// public func _bjs_Greeter_init(nameBytes: Int32, nameLen: Int32) -> UnsafeMutableRawPointer {
/// let name = String(unsafeUninitializedCapacity: Int(nameLen)) { b in
/// _swift_js_init_memory(nameBytes, b.baseAddress.unsafelyUnwrapped)
/// return Int(nameLen)
/// }
/// let ret = Greeter(name: name)
/// return Unmanaged.passRetained(ret).toOpaque()
/// }
///
/// @_expose(wasm, "bjs_Greeter_greet")
/// @_cdecl("bjs_Greeter_greet")
/// public func _bjs_Greeter_greet(pointer: UnsafeMutableRawPointer) -> Void {
/// let _self = Unmanaged<Greeter>.fromOpaque(pointer).takeUnretainedValue()
/// var ret = _self.greet()
/// return ret.withUTF8 { ptr in
/// _swift_js_return_string(ptr.baseAddress, Int32(ptr.count))
/// }
/// }
/// @_expose(wasm, "bjs_Greeter_deinit")
/// @_cdecl("bjs_Greeter_deinit")
/// public func _bjs_Greeter_deinit(pointer: UnsafeMutableRawPointer) {
/// Unmanaged<Greeter>.fromOpaque(pointer).release()
/// }
/// ```
func renderSingleExportedClass(klass: ExportedClass) throws -> [DeclSyntax] {
var decls: [DeclSyntax] = []
if let constructor = klass.constructor {
decls.append(
try renderSingleExportedConstructor(
constructor: constructor,
callName: klass.swiftCallName,
returnType: .swiftHeapObject(klass.name)
)
)
}
for method in klass.methods {
decls.append(
try renderSingleExportedMethod(
method: method,
ownerTypeName: klass.swiftCallName,
instanceSelfType: .swiftHeapObject(klass.swiftCallName)
)
)
}
// Generate property getters and setters
for property in klass.properties {
let context: PropertyRenderingContext =
property.isStatic ? .classStatic(klass: klass) : .classInstance(klass: klass)
decls.append(contentsOf: try renderSingleExportedProperty(property: property, context: context))
}
do {
let funcDecl = SwiftCodePattern.buildExposedFunctionDecl(
abiName: "bjs_\(klass.name)_deinit",
signature: SwiftSignatureBuilder.buildABIFunctionSignature(
abiParameters: [("pointer", .pointer)],
returnType: nil
)
) { printer in
printer.write("Unmanaged<\(klass.swiftCallName)>.fromOpaque(pointer).release()")
}
decls.append(DeclSyntax(funcDecl))
}
// Generate ConvertibleToJSValue extension
decls.append(contentsOf: renderConvertibleToJSValueExtension(klass: klass))
return decls
}
/// Generates a ConvertibleToJSValue extension for the exported class
///
/// # Example
///
/// For a class named `Greeter`, this generates:
///
/// ```swift
/// extension Greeter: ConvertibleToJSValue, _BridgedSwiftHeapObject {
/// var jsValue: JSValue {
/// return JSObject(id: UInt32(bitPattern: _bjs_Greeter_wrap(Unmanaged.passRetained(self).toOpaque())))
/// }
/// }
/// @_extern(wasm, module: "MyModule", name: "bjs_Greeter_wrap")
/// fileprivate func _bjs_Greeter_wrap(_: UnsafeMutableRawPointer) -> Int32
/// ```
func renderConvertibleToJSValueExtension(klass: ExportedClass) -> [DeclSyntax] {
let wrapFunctionName = "_bjs_\(klass.name)_wrap"
let externFunctionName = "bjs_\(klass.name)_wrap"
// If the class has an explicit access control, we need to add it to the extension declaration.
let accessControl = klass.explicitAccessControl.map { "\($0) " } ?? ""
let extensionDecl: DeclSyntax = """
extension \(raw: klass.swiftCallName): ConvertibleToJSValue, _BridgedSwiftHeapObject {
\(raw: accessControl)var jsValue: JSValue {
return .object(JSObject(id: UInt32(bitPattern: \(raw: wrapFunctionName)(Unmanaged.passRetained(self).toOpaque()))))
}
}
"""
// Build common function signature
let funcSignature = SwiftSignatureBuilder.buildABIFunctionSignature(
abiParameters: [("pointer", .pointer)],
returnType: .i32
)
let externDeclPrinter = CodeFragmentPrinter()
SwiftCodePattern.buildWasmConditionalCompilationDecls(
printer: externDeclPrinter,
wasmDecl: { printer in
SwiftCodePattern.buildExternFunctionDecl(
printer: printer,
moduleName: moduleName,
abiName: externFunctionName,
functionName: wrapFunctionName,
signature: funcSignature
)
},
elseDecl: { printer in
printer.write(
multilineString: """
fileprivate func \(wrapFunctionName)\(funcSignature) {
fatalError("Only available on WebAssembly")
}
"""
)
}
)
let externDecl: DeclSyntax = "\(raw: externDeclPrinter.lines.joined(separator: "\n"))"
return [extensionDecl, externDecl]
}
}
// MARK: - StackCodegen
/// Helper for stack-based lifting and lowering operations.
struct StackCodegen {
/// Generates an expression to lift a value from the parameter stack.
/// - Parameter type: The BridgeType to lift
/// - Returns: An ExprSyntax representing the lift expression
func liftExpression(for type: BridgeType) -> ExprSyntax {
switch type {
case .string, .int, .uint, .bool, .float, .double,
.jsObject(nil), .jsValue, .swiftStruct, .swiftHeapObject, .unsafePointer,
.swiftProtocol, .caseEnum, .associatedValueEnum, .rawValueEnum:
return "\(raw: type.swiftType).bridgeJSLiftParameter()"
case .jsObject(let className?):
return "\(raw: className)(unsafelyWrapping: JSObject.bridgeJSLiftParameter())"
case .nullable(let wrappedType, let kind):
return liftNullableExpression(wrappedType: wrappedType, kind: kind)
case .array(let elementType):
return liftArrayExpression(elementType: elementType)
case .dictionary(let valueType):
return liftDictionaryExpression(valueType: valueType)
case .closure:
return "JSObject.bridgeJSLiftParameter()"
case .void, .namespaceEnum:
return "()"
}
}
func liftArrayExpression(elementType: BridgeType) -> ExprSyntax {
switch elementType {
case .jsObject(let className?) where className != "JSObject":
return "[JSObject].bridgeJSLiftParameter().map { \(raw: className)(unsafelyWrapping: $0) }"
case .nullable, .closure:
return liftArrayExpressionInline(elementType: elementType)
case .void, .namespaceEnum:
fatalError("Invalid array element type: \(elementType)")
default:
return "[\(raw: elementType.swiftType)].bridgeJSLiftParameter()"
}
}
private func liftArrayExpressionInline(elementType: BridgeType) -> ExprSyntax {
let elementLift = liftExpression(for: elementType)
let swiftTypeName = elementType.swiftType
return """
{
let __count = Int(_swift_js_pop_i32())
var __result: [\(raw: swiftTypeName)] = []
__result.reserveCapacity(__count)
for _ in 0..<__count {
__result.append(\(elementLift))
}
__result.reverse()
return __result
}()
"""
}
func liftDictionaryExpression(valueType: BridgeType) -> ExprSyntax {
switch valueType {
case .jsObject(let className?) where className != "JSObject":
return """
{
let __dict = [String: JSObject].bridgeJSLiftParameter()
return __dict.mapValues { \(raw: className)(unsafelyWrapping: $0) }
}()
"""
case .nullable, .closure:
return liftDictionaryExpressionInline(valueType: valueType)
case .void, .namespaceEnum:
fatalError("Invalid dictionary value type: \(valueType)")
default:
return "[String: \(raw: valueType.swiftType)].bridgeJSLiftParameter()"
}
}
private func liftDictionaryExpressionInline(valueType: BridgeType) -> ExprSyntax {
let valueLift = liftExpression(for: valueType)
let swiftTypeName = valueType.swiftType
return """
{
let __count = Int(_swift_js_pop_i32())
var __result: [String: \(raw: swiftTypeName)] = [:]
__result.reserveCapacity(__count)
for _ in 0..<__count {
let __value = \(valueLift)
let __key = String.bridgeJSLiftParameter()
__result[__key] = __value
}
return __result
}()
"""
}
private func liftNullableExpression(wrappedType: BridgeType, kind: JSOptionalKind) -> ExprSyntax {
let typeName = kind == .null ? "Optional" : "JSUndefinedOr"
switch wrappedType {
case .string, .int, .uint, .bool, .float, .double, .jsObject(nil), .jsValue,
.swiftStruct, .swiftHeapObject, .caseEnum, .associatedValueEnum, .rawValueEnum,
.array, .dictionary:
return "\(raw: typeName)<\(raw: wrappedType.swiftType)>.bridgeJSLiftParameter()"
case .jsObject(let className?):
return "\(raw: typeName)<JSObject>.bridgeJSLiftParameter().map { \(raw: className)(unsafelyWrapping: $0) }"
case .nullable, .void, .namespaceEnum, .closure, .unsafePointer, .swiftProtocol:
fatalError("Invalid nullable wrapped type: \(wrappedType)")
}
}
/// Generates statements to lower/push a value onto the stack.
/// - Parameters:
/// - type: The BridgeType to lower
/// - accessor: The expression to access the value (e.g., "self.name" or "paramName")
/// - varPrefix: A unique prefix for intermediate variables
/// - Returns: An array of CodeBlockItemSyntax representing the lowering statements
func lowerStatements(
for type: BridgeType,
accessor: String,
varPrefix: String
) -> [CodeBlockItemSyntax] {
switch type {
case .string, .int, .uint, .bool, .float, .double, .jsValue,
.jsObject(nil), .swiftHeapObject, .unsafePointer, .closure,
.caseEnum, .rawValueEnum:
return ["\(raw: accessor).bridgeJSLowerStackReturn()"]
case .jsObject(_?):
return ["\(raw: accessor).jsObject.bridgeJSLowerStackReturn()"]
case .swiftProtocol:
return ["(\(raw: accessor) as! \(raw: type.swiftType)).bridgeJSLowerStackReturn()"]
case .associatedValueEnum, .swiftStruct:
return ["\(raw: accessor).bridgeJSLowerReturn()"]
case .nullable(let wrappedType, _):
return lowerOptionalStatements(wrappedType: wrappedType, accessor: accessor, varPrefix: varPrefix)
case .void, .namespaceEnum:
return []
case .array(let elementType):
return lowerArrayStatements(elementType: elementType, accessor: accessor, varPrefix: varPrefix)
case .dictionary(let valueType):
return lowerDictionaryStatements(valueType: valueType, accessor: accessor, varPrefix: varPrefix)
}
}
private func lowerArrayStatements(
elementType: BridgeType,
accessor: String,
varPrefix: String
) -> [CodeBlockItemSyntax] {
switch elementType {
case .jsObject(let className?) where className != "JSObject":
return ["\(raw: accessor).map { $0.jsObject }.bridgeJSLowerReturn()"]
case .swiftProtocol:
return ["\(raw: accessor).map { $0 as! \(raw: elementType.swiftType) }.bridgeJSLowerReturn()"]
case .nullable, .closure:
return lowerArrayStatementsInline(
elementType: elementType,
accessor: accessor,
varPrefix: varPrefix
)
case .void, .namespaceEnum:
fatalError("Invalid array element type: \(elementType)")
default:
return ["\(raw: accessor).bridgeJSLowerReturn()"]
}
}
private func lowerArrayStatementsInline(
elementType: BridgeType,
accessor: String,
varPrefix: String
) -> [CodeBlockItemSyntax] {
var statements: [String] = []
let elementVarName = "__bjs_elem_\(varPrefix)"
statements.append("for \(elementVarName) in \(accessor) {")
let elementStatements = lowerStatements(
for: elementType,
accessor: elementVarName,
varPrefix: "\(varPrefix)_elem"
)
for stmt in elementStatements {
statements.append(stmt.description)
}
statements.append("}")
statements.append("_swift_js_push_i32(Int32(\(accessor).count))")
let parsed: CodeBlockItemListSyntax = "\(raw: statements.joined(separator: "\n"))"
return Array(parsed)
}
private func lowerDictionaryStatements(
valueType: BridgeType,
accessor: String,
varPrefix: String
) -> [CodeBlockItemSyntax] {
switch valueType {
case .jsObject(let className?) where className != "JSObject":
return ["\(raw: accessor).mapValues { $0.jsObject }.bridgeJSLowerReturn()"]
case .swiftProtocol:
return ["\(raw: accessor).mapValues { $0 as! \(raw: valueType.swiftType) }.bridgeJSLowerReturn()"]
case .nullable, .closure:
return lowerDictionaryStatementsInline(
valueType: valueType,
accessor: accessor,
varPrefix: varPrefix
)
case .void, .namespaceEnum:
fatalError("Invalid dictionary value type: \(valueType)")
default:
return ["\(raw: accessor).bridgeJSLowerReturn()"]
}
}
private func lowerDictionaryStatementsInline(
valueType: BridgeType,
accessor: String,
varPrefix: String
) -> [CodeBlockItemSyntax] {
var statements: [CodeBlockItemSyntax] = []
let pairVarName = "__bjs_kv_\(varPrefix)"
statements.append("for \(raw: pairVarName) in \(raw: accessor) {")
statements.append("let __bjs_key_\(raw: varPrefix) = \(raw: pairVarName).key")
statements.append("let __bjs_value_\(raw: varPrefix) = \(raw: pairVarName).value")
let keyStatements = lowerStatements(
for: .string,
accessor: "__bjs_key_\(varPrefix)",
varPrefix: "\(varPrefix)_key"
)
for stmt in keyStatements {
statements.append(stmt)
}
let valueStatements = lowerStatements(
for: valueType,
accessor: "__bjs_value_\(varPrefix)",
varPrefix: "\(varPrefix)_value"
)
for stmt in valueStatements {
statements.append(stmt)
}
statements.append("}")
statements.append("_swift_js_push_i32(Int32(\(raw: accessor).count))")
return statements
}
private func lowerOptionalStatements(
wrappedType: BridgeType,
accessor: String,
varPrefix: String
) -> [CodeBlockItemSyntax] {
switch wrappedType {
case .array, .dictionary, .swiftStruct:
return ["\(raw: accessor).bridgeJSLowerReturn()"]
default:
break
}
var statements: [String] = []
statements.append("let __bjs_isSome_\(varPrefix) = \(accessor) != nil")
statements.append("if let __bjs_unwrapped_\(varPrefix) = \(accessor) {")
let innerStatements = lowerUnwrappedOptionalStatements(
wrappedType: wrappedType,
unwrappedVar: "__bjs_unwrapped_\(varPrefix)"
)
for stmt in innerStatements {
statements.append(stmt.description)
}
statements.append("}")
statements.append("_swift_js_push_i32(__bjs_isSome_\(varPrefix) ? 1 : 0)")