384991 - w(yield) should not cause "yield expression must be parenthesized" syntax error

Status: VERIFIED FIXED

(Core :: JavaScript Engine, defect, P3)

Description

[Jesse Ruderman]

js> (function() { w(yield); })
typein:1: SyntaxError: yield expression must be parenthesized:
typein:1: (function() { w(yield); })
typein:1: ................^

js> (function() { w((yield)); })
function () {
    w((yield));
}

js> (function() { w(1 ? yield : 0); })
function () {
    w(yield);
}

Comment 1

[Brian Crowder]

Not worth blocking on?

Comment 2

[Jesse Ruderman]

js> (function () { f(x = yield); const x; })
function () {
    f(yield);
    const x;
}

Comment 3

[Brendan Eich [:brendan]]

ES4 is not requiring fully parenthesized yield if the yield expression is the only or last actual parameter. Patch shortly.

/be

Comment 4

[Brendan Eich [:brendan]]

Attachment: relaxed ES4 rules

Comment 5

[Brendan Eich [:brendan]]

I'm not in favor of runtime version checking, so these two tests will have to cope -- unless someone feels strongly that those errors should be thrown for version 1.7. A change in non-error semantics would be a different matter. Just relaxing things to permit what was an error before does not motivate me to spend code size and source complexity on version checks.

/be

Comment 6

[Brendan Eich [:brendan]]

Fixed:

js/src/jsparse.c 3.334

/be

Comment 7

[Bob Clary [:bc] (inactive)]

verified linux|mac|windows

/cvsroot/mozilla/js/tests/js1_8/genexps/regress-384991.js,v  <--  regress-384991.js
initial revision: 1.1

Comment 8

[Arthur Stolyar [:nekr]]

Having this problem in Firefox 45.0.1. Have it been regressed?

Screenshot: http://s18.postimg.org/j8rlroi7t/firefox_yield.png

Comment 9

[Tom S [:evilpie]]

This is fixed in Firefox 47: bug 1250589.

Comment 10

[Arthur Stolyar [:nekr]]

Thanks for info! One strange thing here is that real error was 'Constructor ... is undefined' which I spotted by Chrome. Once that error was fixed -- yield was gone as well.

Comment 11

[Tom S [:evilpie]]

Please open a new bug when there is still a problem with Firefox 47 (currently Firefox Developer Edition). Thanks.

Comment 12

[Arthur Stolyar [:nekr]]

I didn't tried in 47. If I will have any problems there, then I will open new one. Thanks.