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Date: Wed, 27 Feb 2008 09:43:03 -0500
From: David Schultz <das@FreeBSD.ORG>
To: John Baldwin <jhb@FreeBSD.ORG>
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	Garrett Wollman <wollman@hergotha.csail.mit.edu>, arch@FreeBSD.ORG
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Cc: arch@FreeBSD.ORG, Garrett Wollman <wollman@hergotha.csail.mit.edu>
Subject: Re: Cleaning up FILE in stdio..
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On Tue, Feb 26, 2008, John Baldwin wrote:
> > I think you have the right idea but this will break the ABI in a way
> > that can't be fudged with symbol versioning.
[...]
> However, I can't fix the fact that our stdio can't handle fd's > SHRT_MAX 
> (again, glibc handles this just fine) w/o making a royal mess.  We could 
> create a new versioned FILE struct (so long as we can recognize the existing 
> FILE struct somehow) and have new fopen()/fdopen()/freopen() symbols that 
> return the new struct but then all the stdio routines would have to check to 
> see if the structure was an old structure explicitly and handle it 
> appropriately if so.  Rather gross.

Symbol versioning also doesn't help the case where a FILE * gets
passed from an app that's using the new symbol to another library
that's using the old symbol, or vise versa. If you do wind up
breaking the ABI again, maybe it's worth it to add an explicit
version number in the FILE struct itself, so we never have to
worry about this again.