874752 - Components.utils.reportError doesn't report a stack trace.

Status: RESOLVED WONTFIX

(Core :: XPConnect, defect)

Description

[Mark Hammond [:markh] [:mhammond]]

If code does something like:

  try {
    do_something_bad();
  } catch (e) {
    Components.utils.reportError(e);
  }

the exception value is written, but no stack information is, which can make debugging difficult.

There are possibly a number of ways to skin that cat - in an ideal world, it could look something like:

  } catch (e) {
    Components.utils.reportException("something bad happened");
  }

and the given message, the pending exception and the stack-trace would all magically be written.  I'd be happy to work on a patch if we can agree on the color...

Comment 1

[Bobby Holley (:bholley)]

Hm, I'm not sure if we currently have any C++ capability for dumping stacks to the error console. I know jetpack catches exceptions and logs them like that:

http://mxr.mozilla.org/mozilla-central/source/addon-sdk/source/lib/sdk/console/traceback.js#74

I really don't want to do any more stack munging and string formatting than we have to in C++. It seems like this is something that could be accomplished with a JSM, no?

Comment 2

[Mark Hammond [:markh] [:mhammond]]

(In reply to Bobby Holley (:bholley) from comment #1)

> It seems like this is something that could be
> accomplished with a JSM, no?

Well, it could be done directly in the code (eg, Cu.reportError(e + e.stack)) - it's just that people tend to not do that so we end up with messages which are far less useful than they could be.

But yeah, I can accept this is probably INVALID/WONTFIX...

Comment 3

[Bobby Holley (:bholley)]

Yeah, this kind of stuff gets incredibly hairy in C++. I think the appropriate way forward here is to design a friendly error reporting API in JS and evangelize it.

Comment 4

[Mark Hammond [:markh] [:mhammond]]

FTR, this got me thinking, which got me searching, which found me http://mxr.mozilla.org/mozilla-central/source/toolkit/devtools/Console.jsm - which really should be that standard mechanism we evangelize...