revert to cdecl-based exports for swift 5.10 compatibility

Author: sliemeobn

Examples/Basic/Package.swift

@@ -4,6 +4,9 @@ import PackageDescription
 
 let package = Package(
     name: "Basic",
+    platforms: [
+        .macOS(.v14)
+    ],
     dependencies: [.package(name: "JavaScriptKit", path: "../../")],
     targets: [
         .executableTarget(

Examples/Embedded/Sources/EmbeddedApp/_thingsThatShouldNotBeNeeded.swift

@@ -2,9 +2,9 @@ import JavaScriptKit
 
 // NOTE: it seems the embedded tree shaker gets rid of these exports if they are not used somewhere
 func _i_need_to_be_here_for_wasm_exports_to_work() {
-    _ = _library_features
-    _ = _call_host_function_impl
-    _ = _free_host_function_impl
+    _ = _swjs_library_features
+    _ = _swjs_call_host_function
+    _ = _swjs_free_host_function
 }
 
 // TODO: why do I need this? and surely this is not ideal... figure this out, or at least have this come from a C lib

Sources/JavaScriptKit/Features.swift

@@ -2,11 +2,17 @@ enum LibraryFeatures {
     static let weakRefs: Int32 = 1 << 0
 }
 
-@_expose(wasm, "swjs_library_features")
-public func _library_features() -> Int32 {
+@_cdecl("_library_features")
+func _library_features() -> Int32 {
     var features: Int32 = 0
 #if !JAVASCRIPTKIT_WITHOUT_WEAKREFS
     features |= LibraryFeatures.weakRefs
 #endif
     return features
 }
+
+#if hasFeature(Embedded)
+// cdecls currently don't work in embedded, and expose for wasm only works >=6.0
+@_expose(wasm, "swjs_library_features")
+public func _swjs_library_features() -> Int32 { _library_features() }
+#endif

Sources/JavaScriptKit/FundamentalObjects/JSClosure.swift

@@ -186,8 +186,8 @@ private func makeAsyncClosure(_ body: @escaping ([JSValue]) async throws -> JSVa
 // └─────────────────────┴──────────────────────────┘
 
 /// Returns true if the host function has been already released, otherwise false.
-@_expose(wasm, "swjs_call_host_function")
-public func _call_host_function_impl(
+@_cdecl("_call_host_function_impl")
+func _call_host_function_impl(
     _ hostFuncRef: JavaScriptHostFuncRef,
     _ argv: UnsafePointer<RawJSValue>, _ argc: Int32,
     _ callbackFuncRef: JavaScriptObjectRef
@@ -217,8 +217,9 @@ extension JSClosure {
     }
 }
 
-@_expose(wasm, "swjs_free_host_function")
-public func _free_host_function_impl(_ hostFuncRef: JavaScriptHostFuncRef) {}
+
+@_cdecl("_free_host_function_impl")
+func _free_host_function_impl(_ hostFuncRef: JavaScriptHostFuncRef) {}
 
 #else
 
@@ -229,8 +230,25 @@ extension JSClosure {
 
 }
 
-@_expose(wasm, "swjs_free_host_function")
-public func _free_host_function_impl(_ hostFuncRef: JavaScriptHostFuncRef) {
+@_cdecl("_free_host_function_impl")
+func _free_host_function_impl(_ hostFuncRef: JavaScriptHostFuncRef) {
     JSClosure.sharedClosures[hostFuncRef] = nil
 }
 #endif
+
+#if hasFeature(Embedded)
+// cdecls currently don't work in embedded, and expose for wasm only works >=6.0
+@_expose(wasm, "swjs_call_host_function")
+public func _swjs_call_host_function(
+        _ hostFuncRef: JavaScriptHostFuncRef,
+        _ argv: UnsafePointer<RawJSValue>, _ argc: Int32,
+        _ callbackFuncRef: JavaScriptObjectRef) -> Bool {
+
+    _call_host_function_impl(hostFuncRef, argv, argc, callbackFuncRef) 
+}
+
+@_expose(wasm, "swjs_free_host_function")
+public func _swjs_free_host_function(_ hostFuncRef: JavaScriptHostFuncRef) {
+    _free_host_function_impl(hostFuncRef)
+}
+#endif

Sources/_CJavaScriptKit/_CJavaScriptKit.c

@@ -13,6 +13,13 @@ extern void *memcpy (void *__restrict, const void *__restrict, size_t);
 #include <stdbool.h>
 
 #endif
+/// The compatibility runtime library version.
+/// Notes: If you change any interface of runtime library, please increment
+/// this and `SwiftRuntime.version` in `./Runtime/src/index.ts`.
+__attribute__((export_name("swjs_library_version")))
+int swjs_library_version(void) {
+    return 708;
+}
 
 __attribute__((export_name("swjs_prepare_host_function_call")))
 void *swjs_prepare_host_function_call(const int argc) {
@@ -24,14 +31,33 @@ void swjs_cleanup_host_function_call(void *argv_buffer) {
     free(argv_buffer);
 }
 
-/// The compatibility runtime library version.
-/// Notes: If you change any interface of runtime library, please increment
-/// this and `SwiftRuntime.version` in `./Runtime/src/index.ts`.
-__attribute__((export_name("swjs_library_version")))
-int swjs_library_version(void) {
-    return 708;
+#ifndef __Embedded
+// cdecls don't work in Embedded, also @_expose(wasm) can be used with Swift >=6.0
+bool _call_host_function_impl(const JavaScriptHostFuncRef host_func_ref,
+                              const RawJSValue *argv, const int argc,
+                              const JavaScriptObjectRef callback_func);
+
+__attribute__((export_name("swjs_call_host_function")))
+bool swjs_call_host_function(const JavaScriptHostFuncRef host_func_ref,
+                             const RawJSValue *argv, const int argc,
+                             const JavaScriptObjectRef callback_func) {
+    return _call_host_function_impl(host_func_ref, argv, argc, callback_func);
+}
+
+void _free_host_function_impl(const JavaScriptHostFuncRef host_func_ref);
+
+__attribute__((export_name("swjs_free_host_function")))
+void swjs_free_host_function(const JavaScriptHostFuncRef host_func_ref) {
+    _free_host_function_impl(host_func_ref);
 }
 
+int _library_features(void);
+
+__attribute__((export_name("swjs_library_features")))
+int swjs_library_features(void) {
+    return _library_features();
+}
+#endif
 #endif
 
 _Thread_local void *swjs_thread_local_closures;