516733 - Breakpad minidumps should report JavaScript file and line

Status: RESOLVED INCOMPLETE

(Core :: JavaScript Engine, defect)

Description

[Jim Blandy :jimb]

Looking at bug 514593, it seems to me that it might be possible to include JavaScript filenames/URLs and line numbers in crash reports --- just the most recently executed opcode.

The idea would be:
- If breakpad doesn't already have one, add a hook to allow the application to include its own streams in the minidump.
- Have Firefox do a skidmark-like thing recording when JS execution begins and ends in a given context.
- Use the breakpad hook mentioned above to add a stream to the minidump that extracts the current source and line number from the context's top frame, and puts it in a stream.  This would need to be done carefully, as the contents of the data structures being used could not be trusted.
- Have the processor include that stream's contents in the crash report, if present.

Comment 1

[(not currently active) Ted Mielczarek]

Related: bug 510505 (has a patch)
gal also suggests: bug 504949

Comment 2

[Jim Blandy :jimb]

<ted> adding stuff to the minidump sounds like more of a pain
<ted> i just stick it in the .extra file, which we wind up sending as separate
      parameters in a HTTP POST

Comment 3

[(not currently active) Ted Mielczarek]

Also from IRC:
<ted> jimb: also, i'd be interested to figure out the practical implementation issues in letting spidermonkey communicate info to breakpad
<jimb> ted: I was thinking one would have to add JSAPI functions that would have SpiderMonkey do the right callbacks.  That way, we could keep all the breakpad knowledge out of SpiderMonkey, in more appropriate place.