Add support for TRUSTED_TYPES when using Wasm Workers

src/lib/libwasm_worker.js

@@ -34,6 +34,15 @@
 
 {{{
   const workerSupportsFutexWait = () => AUDIO_WORKLET ? "typeof AudioWorkletGlobalScope === 'undefined'" : '1';
+  const wasmWorkerJs = `
+#if WASM_WORKERS == 2
+    _wasmWorkerBlobUrl
+#elif MINIMAL_RUNTIME
+    Module['$wb']
+#else
+    locateFile('${WASM_WORKER_FILE}')
+#endif
+`;
   null;
 }}}
 
@@ -170,21 +179,17 @@ if (ENVIRONMENT_IS_WASM_WORKER
       return 0;
     }
 #endif
-    let worker = _wasmWorkers[_wasmWorkersID] = new Worker(
-#if WASM_WORKERS == 2
-      // WASM_WORKERS=2 mode embeds .ww.js file contents into the main .js file
-      // as a Blob URL. (convenient, but not CSP security safe, since this is
-      // eval-like)
-      _wasmWorkerBlobUrl
-#elif MINIMAL_RUNTIME
-      // MINIMAL_RUNTIME has a structure where the .ww.js file is loaded from
-      // the main HTML file in parallel to all other files for best performance
-      Module['$wb'] // $wb="Wasm worker Blob", abbreviated since not DCEable
-#else
-      // default runtime loads the .ww.js file on demand.
-      locateFile('{{{ WASM_WORKER_FILE }}}')
-#endif
-    );
+    let worker;
+#if TRUSTED_TYPES
+    // Use Trusted Types compatible wrappers.
+    if (typeof trustedTypes != 'undefined' && trustedTypes.createPolicy) {
+      var p = trustedTypes.createPolicy(
+          'emscripten#workerPolicy1', { createScriptURL: (ignored) => {{{ wasmWorkerJs }}}}
+      );
+      worker = _wasmWorkers[_wasmWorkersID] = new Worker(p.createScriptURL('ignored'));
+    } else
+#endif
+    worker = _wasmWorkers[_wasmWorkersID] = new Worker({{{ wasmWorkerJs }}});
     // Craft the Module object for the Wasm Worker scope:
     worker.postMessage({
       // Signal with a non-zero value that this Worker will be a Wasm Worker,

src/wasm_worker.js

@@ -58,6 +58,13 @@ if (ENVIRONMENT_IS_NODE) {
 #endif
 #if !MINIMAL_RUNTIME
   d['instantiateWasm'] = (info, receiveInstance) => { var instance = new WebAssembly.Instance(d['wasm'], info); return receiveInstance(instance, d['wasm']); }
+#endif
+#if TRUSTED_TYPES
+  // Use Trusted Types compatible wrappers.
+  if (typeof trustedTypes != 'undefined' && trustedTypes.createPolicy) {
+    var p = trustedTypes.createPolicy('emscripten#scriptPolicy1', { createScriptURL: (ignored) => d.js });
+    importScripts(p.createScriptURL('ignored'));
+  } else
 #endif
   importScripts(d.js);
 #if MODULARIZE

test/code_size/hello_wasm_worker_wasm.js

@@ -8,28 +8,28 @@ var b = Module, c = !!b.$ww, e = b.mem || new WebAssembly.Memory({
     d && h.get(d)(...a.x);
 }, l = a => {
     g.push(a);
-}, m = {}, n = 1, p, q;
+}, n = {}, p = 1, q, r;
 
-c && (m[0] = this, addEventListener("message", l));
+c && (n[0] = this, addEventListener("message", l));
 
 WebAssembly.instantiate(b.wasm, {
     a: {
         b: (a, d) => {
-            let r = m[n] = new Worker(b.$wb);
-            r.postMessage({
-                $ww: n,
+            let m = n[p] = new Worker(b.$wb);
+            m.postMessage({
+                $ww: p,
                 wasm: b.wasm,
                 js: b.js,
                 mem: e,
                 sb: a,
                 sz: d
             });
-            r.onmessage = k;
-            return n++;
+            m.onmessage = k;
+            return p++;
         },
         c: () => !1,
         d: (a, d) => {
-            m[a].postMessage({
+            n[a].postMessage({
                 _wsc: d,
                 x: []
             });
@@ -41,10 +41,10 @@ WebAssembly.instantiate(b.wasm, {
     }
 }).then((a => {
     a = a.instance.exports;
-    p = a.g;
-    q = a.i;
+    q = a.g;
+    r = a.i;
     h = a.h;
-    c ? (a = b, q(a.sb, a.sz), removeEventListener("message", l), g = g.forEach(k), 
+    c ? (a = b, r(a.sb, a.sz), removeEventListener("message", l), g = g.forEach(k), 
     addEventListener("message", k)) : a.f();
-    c || p();
+    c || q();
 }));

test/test_other.py

@@ -14411,8 +14411,12 @@ def test_debug_opt_warning(self, should_fail, args):
     else:
       self.run_process([EMCC, test_file('hello_world.c'), '-Werror'] + args)
 
-  def test_wasm_worker_hello(self):
-    self.do_runf('wasm_worker/hello_wasm_worker.c', emcc_args=['-sWASM_WORKERS'])
+  @parameterized({
+    '': [[]],
+    'trusted': [['-sTRUSTED_TYPES']]
+  })
+  def test_wasm_worker_hello(self, args):
+    self.do_runf('wasm_worker/hello_wasm_worker.c', emcc_args=['-sWASM_WORKERS'] + args)
 
   def test_wasm_worker_terminate(self):
     self.do_runf('wasm_worker/terminate_wasm_worker.c', emcc_args=['-sWASM_WORKERS'])