Re: Best way of compiling applications to run on older linux distros

[Andrew Haley <aph at redhat dot com>]

Tom Quarendon wrote:
>> Right.  Like most systems, it's backwards compatible but not forwards.
>> Forwards compatibility is in general impossible since APIs are added
>> from time to time.
> 
> But is works just fine on Windows. You compile specifying the os level
> you're targetting and all later APIs are #ifdeffed out so you can't use
> them. The resulting executable then works quite happily on the older
> version of the OS. All of the OS entry points have fixed IDs in the run
> time library, so there's no API compatibility, or ABI compatibility
> issues, only semantic ones, and generally they're pretty careful about
> that.

Perhaps, but this isn't simply a matter of OS entry points but also that
of other libraries that gcc uses.  In any case, I'm not here to argue
about Windows.

> The issue we're having on linux seems to be to do with the dynamic
> loading hash table incompatbility, and the level of libstdc++ shared
> object.

libstdc++ is part of gcc.  When you build gcc you also get the appropriate
version of libstdc++.

Andrew.