Bug 147063 – lexical scoping is broken with respect to "break" and "continue"

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Saam Barati]

There is some silliness in how byte code generator handles push/pop lexical scope and prepareScopeForNextForLoopIteration.
This should be skipped. There is a silly mistake to always assume that scopeRegister() will be the scope in which
we want to grab the parent scope of. This is fundamentally wrong. We want to grab the parent of the corresponding
lexical scope. scopeRegister() just refers to scope stack top which is not always what we want to pop from.

[Saam Barati]

Created attachment 257027 [details]
patch

[Saam Barati]

(In reply to comment #0)
> There is some silliness in how byte code generator handles push/pop lexical
> scope and prepareScopeForNextForLoopIteration.
> This should be skipped. There is a silly mistake to always assume that
> scopeRegister() will be the scope in which
> we want to grab the parent scope of. This is fundamentally wrong. We want to
> grab the parent of the corresponding
> lexical scope. scopeRegister() just refers to scope stack top which is not
> always what we want to pop from.

This assessment is still correct. But it doesn't tell the whole story.
This was a symptom, rather than the leading cause, of the problem this patch fixes.

[WebKit Commit Bot]

Comment on attachment 257027 [details]
patch

Clearing flags on attachment: 257027

Committed r186996: <http://trac.webkit.org/changeset/186996>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Simon Fraser (smfr)]

This broke 11 tests:
https://build.webkit.org/builders/Apple%20Mavericks%2032-bit%20JSC%20%28BuildAndTest%29/builds/11494

[WebKit Commit Bot]

Re-opened since this is blocked by bug 147070

[Saam Barati]

Fixed 32-bit tests. They were timing out. I made the test have fewer loop iterations.

landed in:
http://trac.webkit.org/changeset/187003