545326 - "use strict" doesn't seem to inherit into "new Function"

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[Jesse Ruderman]

js> "use strict"; new Function("with(x) {}"); 
(function anonymous() {with (x) {}})

js> "use strict"; (function anonymous() {with (x) {}})
typein:5: SyntaxError: strict mode code may not contain 'with' statements:
typein:5: "use strict"; (function anonymous() {with (x) {}})
typein:5: .....................................^

This confuses jsfunfuzz.  Is it intentional?

Comment 1

[Jeff Walden [:Waldo]]

Nope, bug.  Also note the similar situation with eval does properly result in a SyntaxError.

Comment 2

[Jeff Walden [:Waldo]]

Er, I'm wrong.  10.1.1 says the function dynamically created when |Function| is called is strict mode if it begins with a strict-mode directive, and it doesn't mention inheriting from the caller.  I guess this makes sense, given that Function creates a function that has no relation to the calling environment (it's scoped globally, not locally).

Nevertheless, I'm still surprised, and I really had thought semantics were supposed to be different on this point.  I can't find any obvious mailing list traffic concerning this decision, so it's plausibly a spec bug.  I'll send a query tomorrow.

Comment 3

[Jeff Walden [:Waldo]]

Further on the global/local scoping bit, consider this, which produces 2:

javascript:var a=2;function c(){var a=3;return Function("return a");}; c()()