Is Mach-O JIT info generated correctly about v8-perf

[mraleph]

If at the same V8 version you have line info on Linux and not on Mac OS X that probably means Mach-O is potentially malformed. I'd just throw some printf's into https://github.com/v8/v8-git-mirror/blob/master/src/gdb-jit.cc#L1791and see if it tries to generate it at all. Then see what it generates and what it registers.

There is also FLAG_gdbjit_dump (in DEBUG build) that would force V8 to dump all object files it generates in memory (to verify that they reach LLDB untruncated)

[thlorenz]

I did try FLAG_gdbjit_dump which resulted in lots of elfs in my /tmp folder.
I wasn't sure what to do with those since after all I'm on OSX. Dumping symbols out of them lead to nothing useful.

I'll try to look at more details by logging inside gdb-jit.cc, thanks.

[mraleph]

@thlorenz I doubt they are elf's, they are just called this way. I suggest dumping them just to check the size it should match the size you are seeing in the LLDB.

[mraleph]

[if they actually are elf's and not MachO that means V8 does not understand it needs to generate Mach-O files]

[thlorenz]

Ok, makes sense, as i said I was able to dwarfdump them, so most likely not really elfs.
However as I mentioned no useful info was contained in them.

I'll dig more in that direction and possibly attach some generated object files somewhere to figure this out.