Bug 1658160 - Give shell workers a module loader r=jonco

Differential Revision: https://phabricator.services.mozilla.com/D86568

js/src/shell/js.cpp

@@ -538,6 +538,8 @@ bool shell::dumpEntrainedVariables = false;
 bool shell::OOM_printAllocationCount = false;
 #endif
 
+UniqueChars shell::processWideModuleLoadPath;
+
 static bool SetTimeoutValue(JSContext* cx, double t);
 
 static void KillWatchdog(JSContext* cx);
@@ -4131,6 +4133,7 @@ static void WorkerMain(WorkerInput* input) {
   });
 
   sc->isWorker = true;
+
   JS_SetContextPrivate(cx, sc);
   JS_SetGrayGCRootsTracer(cx, TraceGrayRoots, nullptr);
   SetWorkerContextOptions(cx);
@@ -4168,6 +4171,16 @@ static void WorkerMain(WorkerInput* input) {
 
     JSAutoRealm ar(cx, global);
 
+    JS::ConstUTF8CharsZ path(processWideModuleLoadPath.get(), strlen(processWideModuleLoadPath.get()));
+    RootedString moduleLoadPath(cx, JS_NewStringCopyUTF8Z(cx, path));
+    if (!moduleLoadPath) {
+      return;
+    }
+    sc->moduleLoader = js::MakeUnique<ModuleLoader>();
+    if (!sc->moduleLoader || !sc->moduleLoader->init(cx, moduleLoadPath)) {
+      return;
+    }
+
     JS::CompileOptions options(cx);
     options.setFileAndLine("<string>", 1).setIsRunOnce(true);
 
@@ -10084,6 +10097,12 @@ static MOZ_MUST_USE bool ProcessArgs(JSContext* cx, OptionParser* op) {
     return false;
   }
 
+  processWideModuleLoadPath = JS_EncodeStringToUTF8(cx, moduleLoadPath);
+  if (!processWideModuleLoadPath) {
+    MOZ_ASSERT(cx->isExceptionPending());
+    return false;
+  }
+
   sc->moduleLoader = js::MakeUnique<ModuleLoader>();
   if (!sc->moduleLoader || !sc->moduleLoader->init(cx, moduleLoadPath)) {
     return false;

js/src/shell/jsshell.h

@@ -158,6 +158,8 @@ extern bool dumpEntrainedVariables;
 extern bool OOM_printAllocationCount;
 #endif
 
+extern UniqueChars processWideModuleLoadPath;
+
 // Alias the global dstName to namespaceObj.srcName. For example, if dstName is
 // "snarf", namespaceObj represents "os.file", and srcName is "readFile", then
 // this is equivalent to the JS code: