Bug 514581 - ES5: fun.caller and fun.arguments must throw when fun is strict-mode code. r=jimb

js/src/js.msg

@@ -331,3 +331,4 @@ MSG_DEF(JSMSG_BAD_GET_SET_FIELD,      248, 1, JSEXN_TYPEERR, "property descripto
 MSG_DEF(JSMSG_BAD_PROXY_FIX,          249, 0, JSEXN_TYPEERR, "proxy was fixed while executing the handler")
 MSG_DEF(JSMSG_INVALID_EVAL_SCOPE_ARG, 250, 0, JSEXN_EVALERR, "invalid eval scope argument")
 MSG_DEF(JSMSG_ACCESSOR_WRONG_ARGS,    251, 3, JSEXN_SYNTAXERR, "{0} functions must have {1} argument{2}")
+MSG_DEF(JSMSG_THROW_TYPE_ERROR,       252, 0, JSEXN_TYPEERR, "'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them")

js/src/jsapi.h

@@ -1664,6 +1664,12 @@ struct JSClass {
 #define JSCLASS_MARK_IS_TRACE           (1<<(JSCLASS_HIGH_FLAGS_SHIFT+3))
 #define JSCLASS_INTERNAL_FLAG2          (1<<(JSCLASS_HIGH_FLAGS_SHIFT+4))
 
+/* Additional global reserved slots, beyond those for standard prototypes. */
+#define JSRESERVED_GLOBAL_SLOTS_COUNT     3
+#define JSRESERVED_GLOBAL_COMPARTMENT     (JSProto_LIMIT * 3)
+#define JSRESERVED_GLOBAL_THIS            (JSRESERVED_GLOBAL_COMPARTMENT + 1)
+#define JSRESERVED_GLOBAL_THROWTYPEERROR  (JSRESERVED_GLOBAL_THIS + 1)
+
 /*
  * ECMA-262 requires that most constructors used internally create objects
  * with "the original Foo.prototype value" as their [[Prototype]] (__proto__)
@@ -1675,11 +1681,9 @@ struct JSClass {
  * with the following flags. Failure to use JSCLASS_GLOBAL_FLAGS was
  * prevously allowed, but is now an ES5 violation and thus unsupported.
  */
-#define JSCLASS_GLOBAL_FLAGS \
+#define JSCLASS_GLOBAL_FLAGS                                                  \
-    (JSCLASS_IS_GLOBAL | JSCLASS_HAS_RESERVED_SLOTS(JSProto_LIMIT * 3 + 2))
+    (JSCLASS_IS_GLOBAL |                                                      \
-
+     JSCLASS_HAS_RESERVED_SLOTS(JSProto_LIMIT * 3 + JSRESERVED_GLOBAL_SLOTS_COUNT))
-#define JSRESERVED_GLOBAL_COMPARTMENT (JSProto_LIMIT * 3)
-#define JSRESERVED_GLOBAL_THIS        (JSRESERVED_GLOBAL_COMPARTMENT + 1)
 
 /* Fast access to the original value of each standard class's prototype. */
 #define JSCLASS_CACHED_PROTO_SHIFT      (JSCLASS_HIGH_FLAGS_SHIFT + 8)

js/src/jsfun.cpp

@@ -87,6 +87,12 @@
 
 using namespace js;
 
+inline JSObject *
+JSObject::getThrowTypeError() const
+{
+    return &getGlobal()->getReservedSlot(JSRESERVED_GLOBAL_THROWTYPEERROR).toObject();
+}
+
 JSBool
 js_GetArgsValue(JSContext *cx, JSStackFrame *fp, Value *vp)
 {
@@ -1385,8 +1391,9 @@ fun_getProperty(JSContext *cx, JSObject *obj, jsid id, Value *vp)
      * Function.prototype object (we use JSPROP_PERMANENT with JSPROP_SHARED
      * to make it appear so).
      *
-     * This code couples tightly to the attributes for lazy_function_props[]
+     * This code couples tightly to the attributes for lazyFunctionDataProps[]
-     * initializers above, and to js_SetProperty and js_HasOwnProperty.
+     * and poisonPillProps[] initializers below, and to js_SetProperty and
+     * js_HasOwnProperty.
      *
      * It's important to allow delegating objects, even though they inherit
      * this getter (fun_getProperty), to override arguments, arity, caller,
@@ -1466,20 +1473,34 @@ fun_getProperty(JSContext *cx, JSObject *obj, jsid id, Value *vp)
     return true;
 }
 
-struct LazyFunctionProp {
+namespace {
+
+struct LazyFunctionDataProp {
     uint16      atomOffset;
     int8        tinyid;
     uint8       attrs;
 };
 
-/* NB: no sentinel at the end -- use JS_ARRAY_LENGTH to bound loops. */
+struct PoisonPillProp {
-static LazyFunctionProp lazy_function_props[] = {
+    uint16       atomOffset;
-    {ATOM_OFFSET(arguments), FUN_ARGUMENTS,  JSPROP_PERMANENT},
+    int8         tinyid;
+};
+
+/* NB: no sentinels at ends -- use JS_ARRAY_LENGTH to bound loops. */
+
+const LazyFunctionDataProp lazyFunctionDataProps[] = {
     {ATOM_OFFSET(arity),     FUN_ARITY,      JSPROP_PERMANENT},
-    {ATOM_OFFSET(caller),    FUN_CALLER,     JSPROP_PERMANENT},
     {ATOM_OFFSET(name),      FUN_NAME,       JSPROP_PERMANENT},
 };
 
+/* Properties censored into [[ThrowTypeError]] in strict mode. */
+const PoisonPillProp poisonPillProps[] = {
+    {ATOM_OFFSET(arguments), FUN_ARGUMENTS },
+    {ATOM_OFFSET(caller),    FUN_CALLER    },
+};
+
+}
+
 static JSBool
 fun_enumerate(JSContext *cx, JSObject *obj)
 {
@@ -1493,13 +1514,20 @@ fun_enumerate(JSContext *cx, JSObject *obj)
     if (!JS_LookupPropertyById(cx, obj, id, &v))
         return false;
 
-    for (uintN i = 0; i < JS_ARRAY_LENGTH(lazy_function_props); i++) {
+    for (uintN i = 0; i < JS_ARRAY_LENGTH(lazyFunctionDataProps); i++) {
-        LazyFunctionProp &lfp = lazy_function_props[i];
+        const LazyFunctionDataProp &lfp = lazyFunctionDataProps[i];
         id = ATOM_TO_JSID(OFFSET_TO_ATOM(cx->runtime, lfp.atomOffset));
         if (!JS_LookupPropertyById(cx, obj, id, &v))
             return false;
     }
 
+    for (uintN i = 0; i < JS_ARRAY_LENGTH(poisonPillProps); i++) {
+        const PoisonPillProp &p = poisonPillProps[i];
+        id = ATOM_TO_JSID(OFFSET_TO_ATOM(cx->runtime, p.atomOffset));
+        if (!JS_LookupPropertyById(cx, obj, id, &v))
+            return false;
+    }
+
     return true;
 }
 
@@ -1575,8 +1603,8 @@ fun_resolve(JSContext *cx, JSObject *obj, jsid id, uintN flags,
         return JS_TRUE;
     }
 
-    for (uintN i = 0; i < JS_ARRAY_LENGTH(lazy_function_props); i++) {
+    for (uintN i = 0; i < JS_ARRAY_LENGTH(lazyFunctionDataProps); i++) {
-        LazyFunctionProp *lfp = &lazy_function_props[i];
+        const LazyFunctionDataProp *lfp = &lazyFunctionDataProps[i];
 
         atom = OFFSET_TO_ATOM(cx->runtime, lfp->atomOffset);
         if (id == ATOM_TO_JSID(atom)) {
@@ -1594,6 +1622,37 @@ fun_resolve(JSContext *cx, JSObject *obj, jsid id, uintN flags,
         }
     }
 
+    for (uintN i = 0; i < JS_ARRAY_LENGTH(poisonPillProps); i++) {
+        const PoisonPillProp &p = poisonPillProps[i];
+
+        atom = OFFSET_TO_ATOM(cx->runtime, p.atomOffset);
+        if (id == ATOM_TO_JSID(atom)) {
+            JS_ASSERT(!IsInternalFunctionObject(obj));
+
+            PropertyOp getter, setter;
+            uintN attrs = JSPROP_PERMANENT;
+            if (fun->isInterpreted() && fun->u.i.script->strictModeCode) {
+                JSObject *throwTypeError = obj->getThrowTypeError();
+
+                getter = CastAsPropertyOp(throwTypeError);
+                setter = CastAsPropertyOp(throwTypeError);
+                attrs |= JSPROP_GETTER | JSPROP_SETTER;
+            } else {
+                getter = fun_getProperty;
+                setter = PropertyStub;
+            }
+
+            if (!js_DefineNativeProperty(cx, obj, ATOM_TO_JSID(atom), UndefinedValue(),
+                                         getter, setter,
+                                         attrs, JSScopeProperty::HAS_SHORTID,
+                                         p.tinyid, NULL)) {
+                return JS_FALSE;
+            }
+            *objp = obj;
+            return JS_TRUE;
+        }
+    }
+
     return JS_TRUE;
 }
 
@@ -2393,20 +2452,43 @@ Function(JSContext *cx, JSObject *obj, uintN argc, Value *argv, Value *rval)
                                          filename, lineno);
 }
 
+namespace {
+
+JSBool
+ThrowTypeError(JSContext *cx, uintN argc, Value *vp)
+{
+    JS_ReportErrorFlagsAndNumber(cx, JSREPORT_ERROR, js_GetErrorMessage, NULL,
+                                 JSMSG_THROW_TYPE_ERROR);
+    return false;
+}
+
+}
+
 JSObject *
 js_InitFunctionClass(JSContext *cx, JSObject *obj)
 {
-    JSObject *proto;
+    JSObject *proto = js_InitClass(cx, obj, NULL, &js_FunctionClass, Function, 1,
-    JSFunction *fun;
+                                   NULL, function_methods, NULL, NULL);
-
-    proto = js_InitClass(cx, obj, NULL, &js_FunctionClass, Function, 1,
-                         NULL, function_methods, NULL, NULL);
     if (!proto)
         return NULL;
-    fun = js_NewFunction(cx, proto, NULL, 0, JSFUN_INTERPRETED, obj, NULL);
+
+    JSFunction *fun = js_NewFunction(cx, proto, NULL, 0, JSFUN_INTERPRETED, obj, NULL);
     if (!fun)
         return NULL;
     fun->u.i.script = JSScript::emptyScript();
+
+    if (obj->getClass()->flags & JSCLASS_IS_GLOBAL) {
+        /* ES5 13.2.3: Construct the unique [[ThrowTypeError]] function object. */
+        JSObject *throwTypeError =
+            js_NewFunction(cx, NULL, reinterpret_cast<Native>(ThrowTypeError), 0,
+                           JSFUN_FAST_NATIVE, obj, NULL);
+        if (!throwTypeError)
+            return NULL;
+
+        JS_ALWAYS_TRUE(js_SetReservedSlot(cx, obj, JSRESERVED_GLOBAL_THROWTYPEERROR,
+                                          ObjectValue(*throwTypeError)));
+    }
+
     return proto;
 }
 

js/src/jsfun.h

@@ -349,6 +349,10 @@ IsFunctionObject(const js::Value &v, JSObject **funobj)
     (JS_ASSERT((funobj)->isFunction()),                                       \
      (JSFunction *) (funobj)->getPrivate())
 
+extern JSFunction *
+js_NewFunction(JSContext *cx, JSObject *funobj, js::Native native, uintN nargs,
+               uintN flags, JSObject *parent, JSAtom *atom);
+
 namespace js {
 
 /*
@@ -364,6 +368,9 @@ IsInternalFunctionObject(JSObject *funobj)
     return funobj == fun && (fun->flags & JSFUN_LAMBDA) && !funobj->getParent();
 }
     
+extern JSString *
+fun_toStringHelper(JSContext *cx, JSObject *obj, uintN indent);
+
 } /* namespace js */
 
 extern JSObject *
@@ -372,10 +379,6 @@ js_InitFunctionClass(JSContext *cx, JSObject *obj);
 extern JSObject *
 js_InitArgumentsClass(JSContext *cx, JSObject *obj);
 
-extern JSFunction *
-js_NewFunction(JSContext *cx, JSObject *funobj, js::Native native, uintN nargs,
-               uintN flags, JSObject *parent, JSAtom *atom);
-
 extern void
 js_TraceFunction(JSTracer *trc, JSFunction *fun);
 
@@ -555,11 +558,4 @@ js_fun_apply(JSContext *cx, uintN argc, js::Value *vp);
 extern JSBool
 js_fun_call(JSContext *cx, uintN argc, js::Value *vp);
 
-
-namespace js {
-
-extern JSString *
-fun_toStringHelper(JSContext *cx, JSObject *obj, uintN indent);
-
-}
 #endif /* jsfun_h___ */

js/src/jsobj.cpp

@@ -6046,9 +6046,9 @@ JSObject::wrappedObject(JSContext *cx) const
 }
 
 JSObject *
-JSObject::getGlobal()
+JSObject::getGlobal() const
 {
-    JSObject *obj = this;
+    JSObject *obj = const_cast<JSObject *>(this);
     while (JSObject *parent = obj->getParent())
         obj = parent;
     return obj;

js/src/jsobj.h

@@ -418,7 +418,7 @@ struct JSObject {
         parent = newParent;
     }
 
-    JSObject *getGlobal();
+    JSObject *getGlobal() const;
 
     void *getPrivate() const {
         JS_ASSERT(getClass()->flags & JSCLASS_HAS_PRIVATE);
@@ -739,6 +739,8 @@ struct JSObject {
 
     JS_FRIEND_API(JSCompartment *) getCompartment(JSContext *cx);
 
+    inline JSObject *getThrowTypeError() const;
+
     void swap(JSObject *obj);
 
     inline bool canHaveMethodBarrier() const;

js/src/jsscript.cpp

@@ -1000,13 +1000,25 @@ js_NewScriptFromCG(JSContext *cx, JSCodeGenerator *cg)
         {
             /*
              * We can probably use the immutable empty script singleton, just
-             * one hard case (nupvars != 0) may stand in our way.
+             * two hard cases (nupvars != 0, strict mode code) may stand in our
+             * way.
              */
             JSScript *empty = JSScript::emptyScript();
 
             if (cg->flags & TCF_IN_FUNCTION) {
                 fun = cg->fun;
-                JS_ASSERT(FUN_INTERPRETED(fun) && !FUN_SCRIPT(fun));
+                JS_ASSERT(fun->isInterpreted() && !FUN_SCRIPT(fun));
+                if (cg->flags & TCF_STRICT_MODE_CODE) {
+                    /*
+                     * We can't use a script singleton for empty strict mode
+                     * functions because they have poison-pill caller and
+                     * arguments properties:
+                     *
+                     * function strict() { "use strict"; }
+                     * strict.caller; // calls [[ThrowTypeError]] function
+                     */
+                    goto skip_empty;
+                }
                 if (fun->u.i.nupvars != 0) {
                     /*
                      * FIXME: upvar uses that were all optimized away may leave

js/src/tests/ecma_5/Function/function-caller.js

@@ -0,0 +1,76 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+var gTestfile = 'function-caller.js';
+var BUGNUMBER = 514581;
+var summary = "Function.prototype.caller should throw a TypeError for " +
+              "strict-mode functions";
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+// behavior
+
+function expectTypeError(fun)
+{
+  try
+  {
+    fun();
+    throw new Error("didn't throw");
+  }
+  catch (e)
+  {
+    assertEq(e instanceof TypeError, true,
+             "expected TypeError calling function" +
+             ("name" in fun ? " " + fun.name : "") + ", instead got: " + e);
+  }
+}
+
+function bar() { "use strict"; }
+expectTypeError(function barCaller() { bar.caller; });
+
+function baz() { "use strict"; return 17; }
+expectTypeError(function bazCaller() { baz.caller; });
+
+
+// accessor identity
+
+function strictMode() { "use strict"; return 42; }
+var canonicalTTE = Object.getOwnPropertyDescriptor(strictMode, "caller").get;
+
+var barCaller = Object.getOwnPropertyDescriptor(bar, "caller");
+assertEq("get" in barCaller, true);
+assertEq("set" in barCaller, true);
+assertEq(barCaller.get, canonicalTTE);
+assertEq(barCaller.set, canonicalTTE);
+
+var barArguments = Object.getOwnPropertyDescriptor(bar, "arguments");
+assertEq("get" in barArguments, true);
+assertEq("set" in barArguments, true);
+assertEq(barArguments.get, canonicalTTE);
+assertEq(barArguments.set, canonicalTTE);
+
+var bazCaller = Object.getOwnPropertyDescriptor(baz, "caller");
+assertEq("get" in bazCaller, true);
+assertEq("set" in bazCaller, true);
+assertEq(bazCaller.get, canonicalTTE);
+assertEq(bazCaller.set, canonicalTTE);
+
+var bazArguments = Object.getOwnPropertyDescriptor(baz, "arguments");
+assertEq("get" in bazArguments, true);
+assertEq("set" in bazArguments, true);
+assertEq(bazArguments.get, canonicalTTE);
+assertEq(bazArguments.set, canonicalTTE);
+
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("All tests passed!");

js/src/tests/ecma_5/Function/jstests.list

@@ -1,2 +1,3 @@
 url-prefix ../../jsreftest.html?test=ecma_5/Function/
 script 15.3.4.3-01.js
+script function-caller.js