[Mingw-notify] [ mingw-Bugs-2989578 ] GCC 4.5.0 libstdc++ lacks large file support

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Bugs item #2989578, was opened at 2010-04-19 15:13
Message generated for change (Settings changed) made by tdragon
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Category: gcc
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: John E. (tdragon)
Assigned to: Nobody/Anonymous (nobody)
>Summary: GCC 4.5.0 libstdc++ lacks large file support

Initial Comment:
In both of the recent GCC 4.5.0 releases, the fstreams library in libstdc++ will only use 32-bit pointers for all file operations, limiting usable file sizes to 2Gb in a majority of cases. This holds true for both 32-bit and 64-bit targets (the latter running under WOW64, of course). I've attached a testcase that demonstrates this limitation for seek functionality. When operating correctly, it will create an ~3Gb file and print the correct seek offset each line; when this bug appears, it will cap out at 2Gb and print "-1" as the seek offset thereafter.

I've also attached a patch that fixes the problem. It's been tested to work as expected in recent TDM-GCC releases. Rather than fixing the configury's LFS support detection, which might be a fairly involved process, it merely makes libstdc++ use different functions on the MINGW32 platform.

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You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=102435&aid=2989578&group_id=2435