948718 - Use fix_linux_stack.py in-process inside mochitest and reftest

Status: RESOLVED DUPLICATE of bug 1050601

(Testing :: General, defect)

Description

[William Lachance (:wlach)]

Because fix-linux-stack.pl is written in perl, we now have to do all kinds of brittle ugliness to call it outside of the main mochitest/reftest harness (see e.g. bug 924253). We should port it to python and just use the routines directly there.

Comment 1

[Andrew McCreight [:mccr8]]

Attachment: fix_linux_stack.py

In case it is useful, here's my crude porting of fix_macosx_stack.py to work on Linux instead.  It works when I last tested it, but I won't claim it is any good beyond that.

Comment 2

[Andrew McCreight [:mccr8]]

(I had some problem with the Perl script and decided it was easiest to port over the OSX Python script than figure out Perl.)

Comment 3

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Let's put the porting work in bug 914253 and the in-process bits here.

Comment 4

[Eric Rahm [:erahm]]

William, now that |fix-linux-stack.pl| has been ported to Python do you have any specific requirements for an API for usage inside mochitest and reftest?


Currently I believe it just reads from stdin, outputs to stdout, and stores a bunch of global state probably leaving a bunch of addr2line processes open. We'll probably want to encapsulate that inside an actual class that can be cleaned up.

I'm assuming you just want something like:

  class StackFixer:
    def fixSymbols(self, line):
    """Attempts to fix the symbols in the given line, returns the converted line"""

Comment 5

[William Lachance (:wlach)]

Yes, I can't remember if we need context of previous lines to decode the stack? If not, a simple python function would suffice, no need to bother with a class.

Comment 6

[Eric Rahm [:erahm]]

(In reply to William Lachance (:wlach) from comment #5)
> Yes, I can't remember if we need context of previous lines to decode the
> stack? If not, a simple python function would suffice, no need to bother
> with a class.

The context doesn't matter, just one line at a time is fine.

Unfortunately the class is needed for performance reasons -- we maintain a mapping of known frames so that we can avoid having to pipe out to addr2line. Additionally addr2line is kept running for the duration of conversions (my understanding is it takes a _long_ time to launch addr2line and load libxul).

Comment 7

[(not currently active) Ted Mielczarek]

Whatever you do, it would be nice if this script and fix_stack_using_bpsyms wound up with the same interface so we could swap them seamlessly:
http://mxr.mozilla.org/mozilla-central/source/tools/rb/fix_stack_using_bpsyms.py

Comment 8

[Nicholas Nethercote [inactive]]

A way to call in from another script will be a big help for bug 1044709.

Comment 9

[Nicholas Nethercote [inactive]]

Comment on attachment 8345619 [details]
fix_linux_stack.py

This attachment is obsolete now that fix_linux_stack.py has landed.

Comment 10

[Nicholas Nethercote [inactive]]

I ended up fixing this as part of bug 1050601.