Add DOMRefTypes example

DOMRefTypes/.editorconfig

@@ -0,0 +1,3 @@
+[*]
+indent_style = space
+indent_size = 2

DOMRefTypes/.sourcekit-lsp/config.json

@@ -0,0 +1,5 @@
+{
+  "swiftPM": {
+    "swiftSDK": "swift-DEVELOPMENT-SNAPSHOT-2025-08-02-a_wasm-embedded"
+  }
+}

DOMRefTypes/Package.swift

@@ -0,0 +1,37 @@
+// swift-tools-version: 6.0
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import PackageDescription
+
+let linkerSettings: [LinkerSetting] = [
+  .unsafeFlags([
+    "-Xclang-linker", "-mexec-model=reactor",
+    "-Xlinker", "--export-if-defined=__main_argc_argv",
+  ]),
+]
+
+let package = Package(
+  name: "Guest",
+  targets: [
+    .target(
+      name: "externref",
+    ),
+    .executableTarget(
+      name: "RefsTest",
+      dependencies: ["externref"],
+      linkerSettings: linkerSettings,
+    ),
+  ]
+)

DOMRefTypes/Sources/RefsTest/Entrypoint.swift

@@ -0,0 +1,21 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024-2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+@main
+struct Entrypoint {
+  static func main() {
+    var h1 = Document.global.createElement(name: JSString("h1"))
+    let body = Document.global.body
+    body.append(child: h1)
+    h1.innerHTML = JSString("Hello, world!")
+  }
+}

DOMRefTypes/Sources/RefsTest/SwiftBindings.swift

@@ -0,0 +1,85 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024-2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import externref
+
+struct JSObject: ~Copyable {
+  fileprivate let ref: ExternRefIndex
+
+  deinit {
+    freeExternRef(ref)
+  }
+}
+
+struct JSArray: ~Copyable {
+  private let ref: ExternRefIndex
+
+  init() {
+    self.ref = emptyArray()
+  }
+
+  func append(_ object: borrowing JSObject) {
+    arrayPush(ref, object.ref)
+  }
+}
+
+struct JSString: ~Copyable {
+  fileprivate let ref: ExternRefIndex
+
+  deinit {
+    freeExternRef(self.ref)
+  }
+}
+
+extension JSString {
+  init(_ string: StaticString) {
+    self.ref = bridgeString(string.utf8Start, string.utf8CodeUnitCount)
+  }
+
+}
+
+struct HTMLElement: ~Copyable {
+  fileprivate let ref: ExternRefIndex
+
+  func append(child: borrowing HTMLElement) {
+    appendChild(self.ref, child.ref)
+  }
+
+  static let innerHTMLName = JSString("innerHTML")
+
+  var innerHTML: JSString {
+
+    get {
+      JSString(ref: getProp(self.ref, Self.innerHTMLName.ref))
+    }
+
+    set {
+      setProp(self.ref, Self.innerHTMLName.ref, newValue.ref)
+    }
+  }
+}
+
+struct Document: ~Copyable {
+  fileprivate let object: JSObject
+
+  static let global = Document(object: JSObject(ref: getDocument()))
+
+  static let bodyName = JSString("body")
+
+  func createElement(name: borrowing JSString) -> HTMLElement {
+    .init(ref: externref.createElement(name.ref))
+  }
+
+  var body: HTMLElement {
+    HTMLElement(ref: getProp(self.object.ref, Self.bodyName.ref))
+  }
+}

DOMRefTypes/Sources/externref/bridge.c

@@ -0,0 +1,75 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024-2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "dom.h"
+#include "refs.h"
+#include <stdint.h>
+
+static __externref_t table[0];
+
+typedef __externref_t (*__funcref funcref_t)(__externref_t);
+static funcref_t ftable[0];
+
+static int nextAvailableTableIndex = 0;
+static const int defaultTableGrowSize = 256;
+
+void freeExternRef(ExternRefIndex ref) {
+  __builtin_wasm_table_set(table, ref.index, __builtin_wasm_ref_null_extern());
+}
+
+ExternRefIndex tableAppend(__externref_t ref) {
+  ExternRefIndex idx = { .index = nextAvailableTableIndex++ };
+
+  if (idx.index >= __builtin_wasm_table_size(table)) {
+    __builtin_wasm_table_grow(table, __builtin_wasm_ref_null_extern(), defaultTableGrowSize);
+  }
+
+  __builtin_wasm_table_set(table, idx.index, ref);
+
+  return idx;
+}
+
+ExternRefIndex createElement(ExternRefIndex name) {
+ return tableAppend(createElementJS(__builtin_wasm_table_get(table, name.index)));
+}
+
+ExternRefIndex getDocument() {
+  return tableAppend(getDocumentJS());
+}
+
+ExternRefIndex getProp(ExternRefIndex self, ExternRefIndex name) {
+  return tableAppend(getPropJS(__builtin_wasm_table_get(table, self.index), __builtin_wasm_table_get(table, name.index)));
+}
+
+int getIntProp(ExternRefIndex self, ExternRefIndex name) {
+  return getIntPropJS(__builtin_wasm_table_get(table, self.index), __builtin_wasm_table_get(table, name.index));
+}
+
+void setProp(ExternRefIndex self, ExternRefIndex name, ExternRefIndex val) {
+  setPropJS(__builtin_wasm_table_get(table, self.index), __builtin_wasm_table_get(table, name.index), __builtin_wasm_table_get(table, val.index));
+}
+
+void appendChild(ExternRefIndex self, ExternRefIndex child) {
+  appendChildJS(__builtin_wasm_table_get(table, self.index), __builtin_wasm_table_get(table, child.index));
+}
+
+ExternRefIndex bridgeString(const uint8_t *str, size_t bytes) {
+  return tableAppend(bridgeStringJS(str, bytes));
+}
+
+ExternRefIndex emptyArray() {
+  return tableAppend(emptyArrayJS());
+}
+
+void arrayPush(ExternRefIndex self, ExternRefIndex element) {
+  arrayPushJS(__builtin_wasm_table_get(table, self.index), __builtin_wasm_table_get(table, element.index));
+}

DOMRefTypes/Sources/externref/dom.h

@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024-2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include <stdint.h>
+
+__attribute__((import_module("js")))
+__attribute__((import_name("getDocument"))) __externref_t
+getDocumentJS(void);
+
+__attribute__((import_module("js")))
+__attribute__((import_name("emptyDictionary"))) __externref_t
+emptyDictionaryJS(void);
+
+__attribute__((import_module("js")))
+__attribute__((import_name("emptyArray"))) __externref_t
+emptyArrayJS(void);
+
+__attribute__((import_module("js")))
+__attribute__((import_name("arrayPush"))) void
+arrayPushJS(__externref_t self, __externref_t element);
+
+__attribute__((import_module("js")))
+__attribute__((import_name("bridgeString"))) __externref_t
+bridgeStringJS(const uint8_t *str, uint32_t bytes);
+
+__attribute__((import_module("js")))
+__attribute__((import_name("setProp"))) void
+setPropJS(__externref_t self, __externref_t name, __externref_t val);
+
+__attribute__((import_module("js")))
+__attribute__((import_name("getProp"))) __externref_t
+getPropJS(__externref_t self, __externref_t name);
+
+
+__attribute__((import_module("js")))
+__attribute__((import_name("getIntProp"))) int
+getIntPropJS(__externref_t self, __externref_t name);
+
+__attribute__((import_module("document")))
+__attribute__((import_name("createElement"))) __externref_t
+createElementJS(__externref_t name);
+
+__attribute__((import_module("document")))
+__attribute__((import_name("appendChild"))) void
+appendChildJS(__externref_t self, __externref_t child);

DOMRefTypes/Sources/externref/include/refs.h

@@ -0,0 +1,40 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024-2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+typedef struct ExternRefIndex {
+  int index;
+} ExternRefIndex;
+
+void freeExternRef(ExternRefIndex);
+
+ExternRefIndex createElement(ExternRefIndex name);
+ExternRefIndex getDocument(void);
+ExternRefIndex getProp(ExternRefIndex self, ExternRefIndex name);
+int getIntProp(ExternRefIndex self, ExternRefIndex name);
+void setProp(ExternRefIndex self, ExternRefIndex name, ExternRefIndex val);
+void appendChild(ExternRefIndex self, ExternRefIndex child);
+ExternRefIndex bridgeString(const uint8_t *str, size_t bytes);
+ExternRefIndex emptyArray(void);
+void arrayPush(ExternRefIndex self, ExternRefIndex element);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */

DOMRefTypes/index.html

@@ -0,0 +1,29 @@
+<!-- This source file is part of the Swift open source project
+
+Copyright (c) 2024 Apple Inc. and the Swift project authors
+Licensed under Apache License v2.0 with Runtime Library Exception
+
+See https://swift.org/LICENSE.txt for license information
+See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors -->
+
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>Swift for WebAssembly Examples</title>
+    <script type="module" src="index.js">
+    </script>
+    <style>
+    body {
+      background-color: black;
+      padding: 1rem;
+    }
+    h1 {
+      font-family: sans-serif;
+      color: white;
+    }
+    </style>
+  </head>
+  <body>
+    <h1 id="wasm-logger">Wasm Reference Types Demo</h1>
+  </body>
+</html>