Bug 1252565 part 1. Push the script environment preparer bits up from XPCJSRuntime to CycleCollectedJSRuntime, because we need them on workers to do ctypes on workers properly. r=bholley

js/xpconnect/src/XPCJSRuntime.cpp

@@ -1343,27 +1343,6 @@ xpc::SimulateActivityCallback(bool aActive)
     XPCJSRuntime::ActivityCallback(XPCJSRuntime::Get(), aActive);
 }
 
-void
-XPCJSRuntime::EnvironmentPreparer::invoke(HandleObject scope, js::ScriptEnvironmentPreparer::Closure& closure)
-{
-    MOZ_ASSERT(NS_IsMainThread());
-    nsIGlobalObject* global = NativeGlobal(scope);
-
-    // Not much we can do if we simply don't have a usable global here...
-    NS_ENSURE_TRUE_VOID(global && global->GetGlobalJSObject());
-    AutoEntryScript aes(global, "JS-engine-initiated execution");
-    aes.TakeOwnershipOfErrorReporting();
-
-    MOZ_ASSERT(!JS_IsExceptionPending(aes.cx()));
-
-    DebugOnly<bool> ok = closure(aes.cx());
-
-    MOZ_ASSERT_IF(ok, !JS_IsExceptionPending(aes.cx()));
-
-    // The AutoEntryScript will check for JS_IsExceptionPending on the
-    // JSContext and report it as needed as it comes off the stack.
-}
-
 // static
 void
 XPCJSRuntime::ActivityCallback(void* arg, bool active)
@@ -3505,7 +3484,6 @@ XPCJSRuntime::Initialize()
         stack->sampleRuntime(runtime);
 #endif
     JS_SetAccumulateTelemetryCallback(runtime, AccumulateTelemetryCallback);
-    js::SetScriptEnvironmentPreparer(runtime, &mEnvironmentPreparer);
     js::SetActivityCallback(runtime, ActivityCallback, this);
     JS_SetInterruptCallback(runtime, InterruptCallback);
     js::SetWindowProxyClass(runtime, &OuterWindowProxyClass);

js/xpconnect/src/xpcprivate.h

@@ -592,11 +592,6 @@ public:
     void AddGCCallback(xpcGCCallback cb);
     void RemoveGCCallback(xpcGCCallback cb);
 
-    struct EnvironmentPreparer : public js::ScriptEnvironmentPreparer {
-        void invoke(JS::HandleObject scope, Closure& closure) override;
-    };
-    EnvironmentPreparer mEnvironmentPreparer;
-
     static void ActivityCallback(void* arg, bool active);
     static bool InterruptCallback(JSContext* cx);
 

xpcom/base/CycleCollectedJSRuntime.cpp

@@ -502,6 +502,7 @@ CycleCollectedJSRuntime::Initialize(JSRuntime* aParentRuntime,
     InstanceClassHasProtoAtDepth
   };
   SetDOMCallbacks(mJSRuntime, &DOMcallbacks);
+  js::SetScriptEnvironmentPreparer(mJSRuntime, &mEnvironmentPreparer);
 
 #ifdef SPIDERMONKEY_PROMISE
   JS::SetEnqueuePromiseJobCallback(mJSRuntime, EnqueuePromiseJobCallback, this);
@@ -1613,3 +1614,28 @@ CycleCollectedJSRuntime::PrepareWaitingZonesForGC()
     mZonesWaitingForGC.Clear();
   }
 }
+
+void
+CycleCollectedJSRuntime::EnvironmentPreparer::invoke(JS::HandleObject scope,
+                                                     js::ScriptEnvironmentPreparer::Closure& closure)
+{
+  nsIGlobalObject* global = xpc::NativeGlobal(scope);
+
+  // Not much we can do if we simply don't have a usable global here...
+  NS_ENSURE_TRUE_VOID(global && global->GetGlobalJSObject());
+
+  bool mainThread = NS_IsMainThread();
+  JSContext* cx =
+    mainThread ? nullptr : nsContentUtils::GetDefaultJSContextForThread();
+  AutoEntryScript aes(global, "JS-engine-initiated execution", mainThread, cx);
+  aes.TakeOwnershipOfErrorReporting();
+
+  MOZ_ASSERT(!JS_IsExceptionPending(aes.cx()));
+
+  DebugOnly<bool> ok = closure(aes.cx());
+
+  MOZ_ASSERT_IF(ok, !JS_IsExceptionPending(aes.cx()));
+
+  // The AutoEntryScript will check for JS_IsExceptionPending on the
+  // JSContext and report it as needed as it comes off the stack.
+}

xpcom/base/CycleCollectedJSRuntime.h

@@ -14,6 +14,7 @@
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/SegmentedVector.h"
 #include "jsapi.h"
+#include "jsfriendapi.h"
 
 #include "nsCycleCollectionParticipant.h"
 #include "nsDataHashtable.h"
@@ -401,6 +402,11 @@ private:
     mPreservedNurseryObjects;
 
   nsTHashtable<nsPtrHashKey<JS::Zone>> mZonesWaitingForGC;
+
+  struct EnvironmentPreparer : public js::ScriptEnvironmentPreparer {
+    void invoke(JS::HandleObject scope, Closure& closure) override;
+  };
+  EnvironmentPreparer mEnvironmentPreparer;
 };
 
 void TraceScriptHolder(nsISupports* aHolder, JSTracer* aTracer);