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Bug 1325473 - "A TypeError should be thrown when accessing 'arguments' or 'caller' on any of the new function types". r=shu

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This commit is contained in:
2016-12-22 16:20:00 +01:00
parent 631ba83416
commit 28354c5944
2 changed files with 54 additions and 2 deletions
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13
js/src/jsfun.cpp
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@ -129,6 +129,11 @@ IsFunctionInStrictMode(JSFunction* fun)
return IsAsmJSStrictModeModuleOrFunction(fun);
}
static bool
IsNewerTypeFunction(JSFunction* fun) {
return fun->isArrow() || fun->isGenerator() || fun->isAsync() || fun->isMethod();
}
// Beware: this function can be invoked on *any* function! That includes
// natives, strict mode functions, bound functions, arrow functions,
// self-hosted functions and constructors, asm.js functions, functions with
@ -142,7 +147,9 @@ ArgumentsRestrictions(JSContext* cx, HandleFunction fun)
// a strict mode function, or a bound function.
// TODO (bug 1057208): ensure semantics are correct for all possible
// pairings of callee/caller.
if (fun->isBuiltin() || IsFunctionInStrictMode(fun) || fun->isBoundFunction()) {
if (fun->isBuiltin() || IsFunctionInStrictMode(fun) ||
fun->isBoundFunction() || IsNewerTypeFunction(fun))
{
ThrowTypeErrorBehavior(cx);
return false;
}
@ -229,7 +236,9 @@ CallerRestrictions(JSContext* cx, HandleFunction fun)
// a strict mode function, or a bound function.
// TODO (bug 1057208): ensure semantics are correct for all possible
// pairings of callee/caller.
if (fun->isBuiltin() || IsFunctionInStrictMode(fun) || fun->isBoundFunction()) {
if (fun->isBuiltin() || IsFunctionInStrictMode(fun) ||
fun->isBoundFunction() || IsNewerTypeFunction(fun))
{
ThrowTypeErrorBehavior(cx);
return false;
}

43
js/src/tests/ecma_6/extensions/newer-type-functions-caller-arguments.js Normal file
View File

@ -0,0 +1,43 @@
// Tests that newer-type functions (i.e. anything not defined by regular function declarations and
// expressions) throw when accessing their 'arguments' and 'caller' properties.
// 9.2.7 (AddRestrictedFunctionProperties) defines accessors on Function.prototype which throw on
// every 'get' and 'set' of 'caller' and 'arguments'.
// Additionally, 16.2 (Forbidden Extensions) forbids adding properties to all non-"legacy" function
// declarations and expressions. This creates the effect that all newer-style functions act like
// strict-mode functions when accessing their 'caller' and 'arguments' properties.
const container = {
async asyncMethod() {},
*genMethod() {},
method() {}
};
[
async function(){},
function*(){},
() => {},
async () => {},
container.asyncMethod,
container.genMethod,
container.method
].forEach(f => {
checkArgumentsAccess(f);
checkCallerAccess(f);
});
function checkArgumentsAccess(f) {
assertThrowsInstanceOf(() => f.arguments, TypeError,
`Expected 'arguments' property access to throw on ${f}`);
}
function checkCallerAccess(f) {
assertThrowsInstanceOf(() => f.caller, TypeError,
`Expected 'caller' property access to throw on ${f}`);
}
if (typeof reportCompare === "function")
reportCompare(true, true);
print("Tests complete");