620316 - WrapEscapingClosure and js::GetCallVarChecked are dead code

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jeff Walden [:Waldo]]

It's unused right now, Brendan claims fallout from bug 558451.  Should it be used, or can it be removed?

Comment 1

[Brendan Eich [:brendan]]

We should be able to write a testcase (or find one from the bug that introduced it: bug 496790) and make it bark on a build before the patch-stack for bug 558451 landed. Checking...

/be

Comment 2

[Jason Orendorff [:jorendorff]]

I added JS_ASSERT(0) to the top of WrapEscapingClosure in jsfun.cpp and ran the test suite. No failures.

I think it has been dead since JSOP_UPVAR was removed (bug 592202). JSOP_UPVAR was used in closures on the assumption that they could not escape. Now we emit JSOP_GETFCSLOT or JSOP_NAME in such cases, and those are harmless (though JSOP_NAME gives the wrong answer).

If WrapEscapingClosure is dead, GetCallVarChecked is definitely dead, as are the _DBG opcodes. There may be more dead code here, but that's enough for one bug.

Taking.

Comment 3

[Jason Orendorff [:jorendorff]]

Attachment: WIP 1

This passes tests just fine, but I can't think of any sane reason for keeping the needsWrapper assertions around, so I'm going to delete those too.

Comment 4

[Jason Orendorff [:jorendorff]]

Attachment: v2

Comment 5

[Brendan Eich [:brendan]]

Comment on attachment 544077 [details] [diff] [review]
v2

Whew, that lightened the load. Should have cleaned this up when UPVAR went, thanks for doing it now.

Rather than leave JSOP_UNUSED23[01234] around, I'd just slide down the ops above.

/be

Comment 6

[(no longer active)]

http://hg.mozilla.org/mozilla-central/rev/9c4e42005bff