GNU gcc upgrades

Another slight annoyance, but more to do with gcc rather than Linux is the way after each upgrade to the glibc libraries, suddenly software which compiled perfectly happily under the previous version, even with -Wall switched on, suddenly starts spitting out 100's of warnings (or even worse errors).

Somehow this makes no sense to me. I could understand 1 or 2 warnings, but why pass from 0 warnings for one version of gcc to not even compiling on the next? 

John

EOM 

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