589318 - guard that eval-in-function frames don't access args

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Luke Wagner [:luke]]

Attachment: patch

Currently, the frame for an eval executed in a function has fp->argc == fp->down->argc and fp->argv == fp->down->argv.  However, our code doesn't really use this: argv/argc use isn't made by the script since its eval and must use JSOP_NAME; arguments-object access explicitly skips eval frames.  This is very good and bug 539144 takes advantage of this: with argv removed, eval-in-function frames only need a copy of the down-frame's (callee, this), and the eval-in-function's argc is 0.  I'd like to get this change reviewed/pushed separately: this patch makes the change without actually removing argv, and asserts that we never access the arguments of an eval-in-function frame.

r?brendan, since he was so enthusiastic in bug 585231 comment 2.

Comment 1

[Brendan Eich [:brendan]]

Comment on attachment 467923 [details] [diff] [review]
patch

I wonder if anyone will notice the exception .stack change. Let's find out!

/be

Comment 2

[Luke Wagner [:luke]]

I like your attitude!

Comment 3

[Luke Wagner [:luke]]

http://hg.mozilla.org/tracemonkey/rev/b0de3d955d52

Comment 4

[Robert Sayre]

http://hg.mozilla.org/mozilla-central/rev/b0de3d955d52