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Re: [PATCH] Ensure __BYTE_ORDER is always set

From
Brian Gernhardt <brian@gernhardtsoftware.com>
Date
Jan 30, 2014, 23:24 UTC
Message-ID
<1E24F82E-3543-459E-9C55-350AE8C4E455@gernhardtsoftware.com>
In-Reply-To
<20140130204538.GA1130@sigill.intra.peff.net>
[Re-send to include the list. Meant to hit reply all, not just reply.]
Show 6 quoted lines
> On Jan 30, 2014, at 3:45 PM, Jeff King <peff@peff.net> wrote:
> 
> I do find the failure mode interesting. The endian-swapping code kicked
> in when it did not, meaning your are on a big-endian system. Is this on
> an ancient PPC Mac? Or is the problem that the code did not kick in when
> it should?
Erm.  I was perhaps writing my analysis too quickly.  I was running on a x86_64 Mac, so it wasn't included when it was supposed to be.  Or whichever you said that I didn't.  ;-)
Show 7 quoted lines
> Either way, we should perhaps be more careful in the bitmap code, too,
> that the values we get are sensible. It's better to die("your bitmap is
> broken") than to read off the end of the array. I can't seem to trigger
> the same failure mode, though. On my x86 system, turning off the
> endian-swap (i.e., the opposite of what should happen) makes t5310 fail,
> but it is because we end up trying to set the bit very far into a
> dynamic bitfield, and die allocating memory.
To be more specific, I hit an assertion failure at in ewah_iterator_next() (ewah/ewah_bitmap.c:355) when running `git rev-list --test-bitmap HEAD` (and others if I don't have it die immediately).  That seems to me that there is a check to ensure it doesn't run off the end.  Perhaps you have assertions disabled so hit an error somewhere else?
~~ Brian Gernhardt
Previous: Jeff KingNext: Jonathan Nieder
Message 7 of 9 in “Ensure __BYTE_ORDER is always set”
  1. Ensure __BYTE_ORDER is always setBrian Gernhardt, Jan 30, 2014
  2. Jeff KingJan 30, 2014
  3. Jeff KingJan 30, 2014
  4. Eric SunshineJan 31, 2014
  5. Jonathan NiederJan 30, 2014
  6. Jeff KingJan 30, 2014
  7. Brian GernhardtJan 30, 2014
  8. Jonathan NiederJan 30, 2014
  9. Jeff KingJan 30, 2014

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