730182 - Show location for "[System Principal]" compartments in about:compartments

Status: RESOLVED FIXED

(Toolkit :: about:memory, defect)

Description

[Nicholas Nethercote [inactive]]

Attachment: patch

"[System Principal]" compartments often have a location.  about:compartments doesn't show that, but it would be useful if it did.

For example, with the about:telemetry add-on installed, I currently get this:

  [System Principal] [2]
  atoms
  moz-nullprincipal:{7bed317a-6c84-4071-b622-f1b1c3d45c7e}

With the attached tiny patch I get this, which is much more informative:

  [System Principal]
  [System Principal], jar:file:///home/njn/.mozilla/firefox/izbukysy.telemetry/extensions/[e-mail]!/bootstrap.js
  atoms
  moz-nullprincipal:{7bed317a-6c84-4071-b622-f1b1c3d45c7e}

I was inspired to make this change when I saw 71 "[System Principal]" compartments being merged, and when I viewed them in about:memory?verbose I saw that most of them had locations... it turns out that an Add-on SDK leak was causing them.

Comment 1

[Bobby Holley (:bholley)]

Comment on attachment 600279 [details] [diff] [review]
patch

I think that memory reporters are the primary consumer of this stuff, so I'll take your word for what we want the strings to look like here.

Can we get test coverage for this stuff though? The fact that we can make this kind of free-form change to the strings without changing any tests is an indication that this stuff can probably break without us (or at least, me) realizing it. They don't have to be involved, just basic smoketesting.

r=bholley once there are tests.

Comment 2

[Bobby Holley (:bholley)]

> Depends on: 699307

Ok, sure. As long as that's in the pipe, feel free to land this.

Comment 3

[Nicholas Nethercote [inactive]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/ee4240bf7523

Comment 4

[Marco Bonardo [:mak]]

https://hg.mozilla.org/mozilla-central/rev/ee4240bf7523