BridgeJS: Gate @_extern/@expose usage behind arch(wasm32)

Author: kateinoigakukun

Plugins/BridgeJS/Sources/BridgeJSTool/ExportSwift.swift

@@ -272,6 +272,7 @@ class ExportSwift {
 
         @_spi(JSObject_id) import JavaScriptKit
 
+        #if arch(wasm32)
         @_extern(wasm, module: "bjs", name: "return_string")
         private func _return_string(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
         @_extern(wasm, module: "bjs", name: "init_memory")
@@ -281,6 +282,7 @@ class ExportSwift {
         private func _swift_js_retain(_ ptr: Int32) -> Int32
         @_extern(wasm, module: "bjs", name: "swift_js_throw")
         private func _swift_js_throw(_ id: Int32)
+        #endif
         """
 
     func renderSwiftGlue() -> String? {
@@ -512,7 +514,11 @@ class ExportSwift {
                 @_expose(wasm, "\(raw: abiName)")
                 @_cdecl("\(raw: abiName)")
                 public func _\(raw: abiName)(\(raw: parameterSignature())) -> \(raw: returnSignature()) {
+                    #if arch(wasm32)
                 \(body)
+                    #else
+                    fatalError("Only available on WebAssembly")
+                    #endif
                 }
                 """
         }

Plugins/BridgeJS/Sources/BridgeJSTool/ImportTS.swift

@@ -241,29 +241,42 @@ struct ImportTS {
         }
 
         func renderImportDecl() -> DeclSyntax {
-            return DeclSyntax(
-                FunctionDeclSyntax(
-                    attributes: AttributeListSyntax(itemsBuilder: {
-                        "@_extern(wasm, module: \"\(raw: moduleName)\", name: \"\(raw: abiName)\")"
-                    }).with(\.trailingTrivia, .newline),
-                    name: .identifier(abiName),
-                    signature: FunctionSignatureSyntax(
-                        parameterClause: FunctionParameterClauseSyntax(parametersBuilder: {
-                            for param in abiParameterSignatures {
-                                FunctionParameterSyntax(
-                                    firstName: .wildcardToken(),
-                                    secondName: .identifier(param.name),
-                                    type: IdentifierTypeSyntax(name: .identifier(param.type.swiftType))
-                                )
-                            }
-                        }),
-                        returnClause: ReturnClauseSyntax(
-                            arrow: .arrowToken(),
-                            type: IdentifierTypeSyntax(name: .identifier(abiReturnType.map { $0.swiftType } ?? "Void"))
-                        )
+            let baseDecl = FunctionDeclSyntax(
+                funcKeyword: .keyword(.func).with(\.trailingTrivia, .space),
+                name: .identifier(abiName),
+                signature: FunctionSignatureSyntax(
+                    parameterClause: FunctionParameterClauseSyntax(parametersBuilder: {
+                        for param in abiParameterSignatures {
+                            FunctionParameterSyntax(
+                                firstName: .wildcardToken().with(\.trailingTrivia, .space),
+                                secondName: .identifier(param.name),
+                                type: IdentifierTypeSyntax(name: .identifier(param.type.swiftType))
+                            )
+                        }
+                    }),
+                    returnClause: ReturnClauseSyntax(
+                        arrow: .arrowToken(),
+                        type: IdentifierTypeSyntax(name: .identifier(abiReturnType.map { $0.swiftType } ?? "Void"))
                     )
                 )
             )
+            var externDecl = baseDecl
+            externDecl.attributes = AttributeListSyntax(itemsBuilder: {
+                "@_extern(wasm, module: \"\(raw: moduleName)\", name: \"\(raw: abiName)\")"
+            }).with(\.trailingTrivia, .newline)
+            var stubDecl = baseDecl
+            stubDecl.body = CodeBlockSyntax {
+                """
+                fatalError("Only available on WebAssembly")
+                """
+            }
+            return """
+                #if arch(wasm32)
+                \(externDecl)
+                #else
+                \(stubDecl)
+                #endif
+                """
         }
 
         func renderThunkDecl(name: String, parameters: [Parameter], returnType: BridgeType) -> DeclSyntax {
@@ -328,11 +341,23 @@ struct ImportTS {
 
         @_spi(JSObject_id) import JavaScriptKit
 
+        #if arch(wasm32)
         @_extern(wasm, module: "bjs", name: "make_jsstring")
-        private func _make_jsstring(_ ptr: UnsafePointer<UInt8>?, _ len: Int32) -> Int32
+        func _make_jsstring(_ ptr: UnsafePointer<UInt8>?, _ len: Int32) -> Int32
+        #else
+        func _make_jsstring(_ ptr: UnsafePointer<UInt8>?, _ len: Int32) -> Int32 {
+            fatalError("Only available on WebAssembly")
+        }
+        #endif
 
+        #if arch(wasm32)
         @_extern(wasm, module: "bjs", name: "init_memory_with_result")
-        private func _init_memory_with_result(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
+        func _init_memory_with_result(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
+        #else
+        func _init_memory_with_result(_ ptr: UnsafePointer<UInt8>?, _ len: Int32) {
+            fatalError("Only available on WebAssembly")
+        }
+        #endif
         """
 
     func renderSwiftThunk(

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/ExportSwiftTests/PrimitiveParameters.swift

@@ -6,6 +6,7 @@
 
 @_spi(JSObject_id) import JavaScriptKit
 
+#if arch(wasm32)
 @_extern(wasm, module: "bjs", name: "return_string")
 private func _return_string(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
 @_extern(wasm, module: "bjs", name: "init_memory")
@@ -15,9 +16,14 @@ private func _init_memory(_ sourceId: Int32, _ ptr: UnsafeMutablePointer<UInt8>?
 private func _swift_js_retain(_ ptr: Int32) -> Int32
 @_extern(wasm, module: "bjs", name: "swift_js_throw")
 private func _swift_js_throw(_ id: Int32)
+#endif
 
 @_expose(wasm, "bjs_check")
 @_cdecl("bjs_check")
 public func _bjs_check(a: Int32, b: Float32, c: Float64, d: Int32) -> Void {
+    #if arch(wasm32)
     check(a: Int(a), b: b, c: c, d: d == 1)
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/ExportSwiftTests/PrimitiveReturn.swift

@@ -6,6 +6,7 @@
 
 @_spi(JSObject_id) import JavaScriptKit
 
+#if arch(wasm32)
 @_extern(wasm, module: "bjs", name: "return_string")
 private func _return_string(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
 @_extern(wasm, module: "bjs", name: "init_memory")
@@ -15,31 +16,48 @@ private func _init_memory(_ sourceId: Int32, _ ptr: UnsafeMutablePointer<UInt8>?
 private func _swift_js_retain(_ ptr: Int32) -> Int32
 @_extern(wasm, module: "bjs", name: "swift_js_throw")
 private func _swift_js_throw(_ id: Int32)
+#endif
 
 @_expose(wasm, "bjs_checkInt")
 @_cdecl("bjs_checkInt")
 public func _bjs_checkInt() -> Int32 {
+    #if arch(wasm32)
     let ret = checkInt()
     return Int32(ret)
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }
 
 @_expose(wasm, "bjs_checkFloat")
 @_cdecl("bjs_checkFloat")
 public func _bjs_checkFloat() -> Float32 {
+    #if arch(wasm32)
     let ret = checkFloat()
     return Float32(ret)
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }
 
 @_expose(wasm, "bjs_checkDouble")
 @_cdecl("bjs_checkDouble")
 public func _bjs_checkDouble() -> Float64 {
+    #if arch(wasm32)
     let ret = checkDouble()
     return Float64(ret)
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }
 
 @_expose(wasm, "bjs_checkBool")
 @_cdecl("bjs_checkBool")
 public func _bjs_checkBool() -> Int32 {
+    #if arch(wasm32)
     let ret = checkBool()
     return Int32(ret ? 1 : 0)
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/ExportSwiftTests/StringParameter.swift

@@ -6,6 +6,7 @@
 
 @_spi(JSObject_id) import JavaScriptKit
 
+#if arch(wasm32)
 @_extern(wasm, module: "bjs", name: "return_string")
 private func _return_string(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
 @_extern(wasm, module: "bjs", name: "init_memory")
@@ -15,13 +16,18 @@ private func _init_memory(_ sourceId: Int32, _ ptr: UnsafeMutablePointer<UInt8>?
 private func _swift_js_retain(_ ptr: Int32) -> Int32
 @_extern(wasm, module: "bjs", name: "swift_js_throw")
 private func _swift_js_throw(_ id: Int32)
+#endif
 
 @_expose(wasm, "bjs_checkString")
 @_cdecl("bjs_checkString")
 public func _bjs_checkString(aBytes: Int32, aLen: Int32) -> Void {
+    #if arch(wasm32)
     let a = String(unsafeUninitializedCapacity: Int(aLen)) { b in
         _init_memory(aBytes, b.baseAddress.unsafelyUnwrapped)
         return Int(aLen)
     }
     checkString(a: a)
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/ExportSwiftTests/StringReturn.swift

@@ -6,6 +6,7 @@
 
 @_spi(JSObject_id) import JavaScriptKit
 
+#if arch(wasm32)
 @_extern(wasm, module: "bjs", name: "return_string")
 private func _return_string(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
 @_extern(wasm, module: "bjs", name: "init_memory")
@@ -15,12 +16,17 @@ private func _init_memory(_ sourceId: Int32, _ ptr: UnsafeMutablePointer<UInt8>?
 private func _swift_js_retain(_ ptr: Int32) -> Int32
 @_extern(wasm, module: "bjs", name: "swift_js_throw")
 private func _swift_js_throw(_ id: Int32)
+#endif
 
 @_expose(wasm, "bjs_checkString")
 @_cdecl("bjs_checkString")
 public func _bjs_checkString() -> Void {
+    #if arch(wasm32)
     var ret = checkString()
     return ret.withUTF8 { ptr in
         _return_string(ptr.baseAddress, Int32(ptr.count))
     }
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/ExportSwiftTests/SwiftClass.swift

@@ -6,6 +6,7 @@
 
 @_spi(JSObject_id) import JavaScriptKit
 
+#if arch(wasm32)
 @_extern(wasm, module: "bjs", name: "return_string")
 private func _return_string(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
 @_extern(wasm, module: "bjs", name: "init_memory")
@@ -15,41 +16,58 @@ private func _init_memory(_ sourceId: Int32, _ ptr: UnsafeMutablePointer<UInt8>?
 private func _swift_js_retain(_ ptr: Int32) -> Int32
 @_extern(wasm, module: "bjs", name: "swift_js_throw")
 private func _swift_js_throw(_ id: Int32)
+#endif
 
 @_expose(wasm, "bjs_takeGreeter")
 @_cdecl("bjs_takeGreeter")
 public func _bjs_takeGreeter(greeter: UnsafeMutableRawPointer) -> Void {
+    #if arch(wasm32)
     takeGreeter(greeter: Unmanaged<Greeter>.fromOpaque(greeter).takeUnretainedValue())
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }
 
 @_expose(wasm, "bjs_Greeter_init")
 @_cdecl("bjs_Greeter_init")
 public func _bjs_Greeter_init(nameBytes: Int32, nameLen: Int32) -> UnsafeMutableRawPointer {
+    #if arch(wasm32)
     let name = String(unsafeUninitializedCapacity: Int(nameLen)) { b in
         _init_memory(nameBytes, b.baseAddress.unsafelyUnwrapped)
         return Int(nameLen)
     }
     let ret = Greeter(name: name)
     return Unmanaged.passRetained(ret).toOpaque()
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }
 
 @_expose(wasm, "bjs_Greeter_greet")
 @_cdecl("bjs_Greeter_greet")
 public func _bjs_Greeter_greet(_self: UnsafeMutableRawPointer) -> Void {
+    #if arch(wasm32)
     var ret = Unmanaged<Greeter>.fromOpaque(_self).takeUnretainedValue().greet()
     return ret.withUTF8 { ptr in
         _return_string(ptr.baseAddress, Int32(ptr.count))
     }
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }
 
 @_expose(wasm, "bjs_Greeter_changeName")
 @_cdecl("bjs_Greeter_changeName")
 public func _bjs_Greeter_changeName(_self: UnsafeMutableRawPointer, nameBytes: Int32, nameLen: Int32) -> Void {
+    #if arch(wasm32)
     let name = String(unsafeUninitializedCapacity: Int(nameLen)) { b in
         _init_memory(nameBytes, b.baseAddress.unsafelyUnwrapped)
         return Int(nameLen)
     }
     Unmanaged<Greeter>.fromOpaque(_self).takeUnretainedValue().changeName(name: name)
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }
 
 @_expose(wasm, "bjs_Greeter_deinit")

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/ExportSwiftTests/Throws.swift

@@ -6,6 +6,7 @@
 
 @_spi(JSObject_id) import JavaScriptKit
 
+#if arch(wasm32)
 @_extern(wasm, module: "bjs", name: "return_string")
 private func _return_string(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
 @_extern(wasm, module: "bjs", name: "init_memory")
@@ -15,10 +16,12 @@ private func _init_memory(_ sourceId: Int32, _ ptr: UnsafeMutablePointer<UInt8>?
 private func _swift_js_retain(_ ptr: Int32) -> Int32
 @_extern(wasm, module: "bjs", name: "swift_js_throw")
 private func _swift_js_throw(_ id: Int32)
+#endif
 
 @_expose(wasm, "bjs_throwsSomething")
 @_cdecl("bjs_throwsSomething")
 public func _bjs_throwsSomething() -> Void {
+    #if arch(wasm32)
     do {
         try throwsSomething()
     } catch let error {
@@ -34,4 +37,7 @@ public func _bjs_throwsSomething() -> Void {
         }
         return
     }
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/ExportSwiftTests/VoidParameterVoidReturn.swift

@@ -6,6 +6,7 @@
 
 @_spi(JSObject_id) import JavaScriptKit
 
+#if arch(wasm32)
 @_extern(wasm, module: "bjs", name: "return_string")
 private func _return_string(_ ptr: UnsafePointer<UInt8>?, _ len: Int32)
 @_extern(wasm, module: "bjs", name: "init_memory")
@@ -15,9 +16,14 @@ private func _init_memory(_ sourceId: Int32, _ ptr: UnsafeMutablePointer<UInt8>?
 private func _swift_js_retain(_ ptr: Int32) -> Int32
 @_extern(wasm, module: "bjs", name: "swift_js_throw")
 private func _swift_js_throw(_ id: Int32)
+#endif
 
 @_expose(wasm, "bjs_check")
 @_cdecl("bjs_check")
 public func _bjs_check() -> Void {
+    #if arch(wasm32)
     check()
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
 }