ASAN specific handling in chaos mode isn't triggered if Firefox is run from `mach`

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
cpp
Domain
devtools

Research direction

Reproduce the failure with rr record -h ./mach run using an ASAN Firefox build, then inspect the ASAN handling in src/AddressSpace.cc and executable checks in src/RecordSession.cc at the referenced lines. Compare this with recording the firefox-bin executable directly. Done means establishing and implementing or documenting a supported way for the mach launch path to use the required ASAN handling.

Written by the indexing model from the issue text.

Description

The handling to prevent chaos mode interfering with ASAN will only kick in if the executable passed to rr is flagged for ASAN. This is because only this executable is checked. My assumption is that it doesn't make sense to do this with later executables as there may then already be existing memory allocations that it is too late to deal with.

This means that something like rr record -h ./mach run will typically fail when it is an ASAN version of Firefox being run. This can be worked around by instead recording the firefox-bin executable that would be called by mach.

I'm not sure if this is a common enough use case to need action. I'm considering a local build with an extra flag that I can pass to force ASAN compat so I can keep using mach, but don't know if that's useful outside of my bubble.

Dominant language
C++
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Merged PRs (30d)
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