Bug 737195 - Add barriers to JSFunction::atom; r=billm

This is only ever initialized, so it needs generational barriers, but not
incremental barriers.

js/src/gc/Barrier.h

@@ -249,6 +249,7 @@ struct Shape;
 class BaseShape;
 namespace types { struct TypeObject; }
 
+typedef HeapPtr<JSAtom> HeapPtrAtom;
 typedef HeapPtr<JSObject> HeapPtrObject;
 typedef HeapPtr<JSFunction> HeapPtrFunction;
 typedef HeapPtr<JSString> HeapPtrString;

js/src/jsfun.cpp

@@ -488,6 +488,7 @@ js::XDRFunctionObject(JSXDRState *xdr, JSObject **objp)
 {
     JSContext *cx;
     JSFunction *fun;
+    JSAtom *atom;
     uint32_t firstword;           /* flag telling whether fun->atom is non-null,
                                    plus for fun->u.i.skipmin, fun->u.i.wrapper,
                                    and 14 bits reserved for future use */
@@ -507,6 +508,7 @@ js::XDRFunctionObject(JSXDRState *xdr, JSObject **objp)
         }
         firstword = !!fun->atom;
         flagsword = (fun->nargs << 16) | fun->flags;
+        atom = fun->atom;
         script = fun->script();
     } else {
         RootedVarObject parent(cx, NULL);
@@ -517,12 +519,13 @@ js::XDRFunctionObject(JSXDRState *xdr, JSObject **objp)
             return false;
         if (!fun->clearType(cx))
             return false;
+        atom = NULL;
         script = NULL;
     }
 
     if (!JS_XDRUint32(xdr, &firstword))
         return false;
-    if ((firstword & 1U) && !js_XDRAtom(xdr, &fun->atom))
+    if ((firstword & 1U) && !js_XDRAtom(xdr, &atom))
         return false;
     if (!JS_XDRUint32(xdr, &flagsword))
         return false;
@@ -534,7 +537,8 @@ js::XDRFunctionObject(JSXDRState *xdr, JSObject **objp)
         fun->nargs = flagsword >> 16;
         JS_ASSERT((flagsword & JSFUN_KINDMASK) >= JSFUN_INTERPRETED);
         fun->flags = uint16_t(flagsword);
-        fun->setScript(script);
+        fun->atom.init(atom);
+        fun->initScript(script);
         if (!script->typeSetFunction(cx, fun))
             return false;
         JS_ASSERT(fun->nargs == fun->script()->bindings.countArgs());
@@ -587,7 +591,7 @@ JSFunction::trace(JSTracer *trc)
     }
 
     if (atom)
-        MarkStringUnbarriered(trc, &atom, "atom");
+        MarkString(trc, &atom, "atom");
 
     if (isInterpreted()) {
         if (u.i.script_)
@@ -1008,7 +1012,7 @@ fun_bind(JSContext *cx, unsigned argc, Value *vp)
     }
 
     /* Step 4-6, 10-11. */
-    JSAtom *name = target->isFunction() ? target->toFunction()->atom : NULL;
+    JSAtom *name = target->isFunction() ? target->toFunction()->atom.get() : NULL;
 
     JSObject *funobj =
         js_NewFunction(cx, NULL, CallOrConstructBoundFunction, length,
@@ -1304,7 +1308,7 @@ js_NewFunction(JSContext *cx, JSObject *funobj, Native native, unsigned nargs,
         fun->flags |= JSFUN_EXTENDED;
         fun->initializeExtended();
     }
-    fun->atom = atom;
+    fun->atom.init(atom);
 
     if (native && !fun->setSingletonType(cx))
         return NULL;
@@ -1332,7 +1336,7 @@ js_CloneFunctionObject(JSContext *cx, JSFunction *fun, JSObject *parent,
     } else {
         clone->u.n = fun->u.n;
     }
-    clone->atom = fun->atom;
+    clone->atom.init(fun->atom);
 
     if (kind == JSFunction::ExtendedFinalizeKind) {
         clone->flags |= JSFUN_EXTENDED;

js/src/jsfun.h

@@ -102,7 +102,7 @@ struct JSFunction : public JSObject
         } i;
         void            *nativeOrScript;
     } u;
-    JSAtom          *atom;        /* name for diagnostics and decompiling */
+    js::HeapPtrAtom  atom;        /* name for diagnostics and decompiling */
 
     bool optimizedClosure()  const { return kind() > JSFUN_INTERPRETED; }
     bool isInterpreted()     const { return kind() >= JSFUN_INTERPRETED; }

js/src/jsobjinlines.h

@@ -666,7 +666,7 @@ namespace js {
 static inline JSAtom *
 CallObjectLambdaName(JSFunction *fun)
 {
-    return (fun->flags & JSFUN_LAMBDA) ? fun->atom : NULL;
+    return (fun->flags & JSFUN_LAMBDA) ? fun->atom.get() : NULL;
 }
 
 } /* namespace js */
@@ -678,7 +678,7 @@ JSObject::getDateUTCTime() const
     return getFixedSlot(JSSLOT_DATE_UTC_TIME);
 }
 
-inline void 
+inline void
 JSObject::setDateUTCTime(const js::Value &time)
 {
     JS_ASSERT(isDate());