533233 - nanojit: get rid of LC_NoCodeAddrs (or do it properly)

Status: RESOLVED FIXED

(Core Graveyard :: Nanojit, defect)

Description

[Nicholas Nethercote [inactive]]

LC_NoCodeAddrs reduces the number of addresses printed in verbose NJ output.  This makes the output less noisy, but enough addresses are still printed that it's not possible to diff two different outputs for changes, which is a procedure that can be very helpful for testing changes.  I've been using a tiny script to strip out addresses as a workaround.

I started trying to fix things so that LC_NoCodeAddrs works properly, but there are enough places where addresses show up in non-trivial ways (eg. "mov %eax,347829374", "jmp 0x433a78c3") that I think that avoiding the addresses is too difficult and using a tiny script is the right way to solve this problem.

(For the record, my script looks like this:

  perl -p -e 's/[0-9a-fA-F]{4,}/.../g'

ie. it just blots out all numbers, decimal or hexadecimal, with 4 or more digits.)

The attached patch gets rid of LC_NoCodeAddrs altogether.  It mixes NJ and TM changes.  If people don't like this approach then LC_NoCodeAddrs should be done properly, but it's more painful than you might think.

Comment 1

[Nicholas Nethercote [inactive]]

Attachment: patch

Comment 2

[Edwin Smith]

Comment on attachment 416384 [details] [diff] [review]
patch

I'm okay with removing the flag, youre right that a script to do it is cleaner.

Comment 3

[Nicholas Nethercote [inactive]]

http://hg.mozilla.org/projects/nanojit-central/rev/5edcef2131df

Comment 4

[Nicholas Nethercote [inactive]]

http://hg.mozilla.org/tracemonkey/rev/c2f17d0cb173

Comment 5

[Nicholas Nethercote [inactive]]

http://hg.mozilla.org/tracemonkey/rev/cb4b7e6fed77

Comment 6

[Nicholas Nethercote [inactive]]

Bustage fix for Linux:

http://hg.mozilla.org/projects/nanojit-central/rev/18cf6386858b

Comment 7

[Nicholas Nethercote [inactive]]

Bustage fix merge to TM:

http://hg.mozilla.org/tracemonkey/rev/a938a7ec9df9

Comment 8

[Robert Sayre]

http://hg.mozilla.org/mozilla-central/rev/c2f17d0cb173