[Zlib-devel] Re: ABI compatibility of zlib 1.0.x, 1.1.x, and 1.2.x

[Cosmin Truta]

On Fri, 5 Dec 2003, Jeff Johnson wrote:

> Cosmin Truta wrote:
>
> >
> >Although it's superfluous, something has to be stated about NOT relying
> >at all on private symbols that leak out of "zlib.h", or on pieces of
> >code that do more than the documentation claims.
> >
>
> There is attribute magic to deal with "symbols that leak" if using
> gcc/binutils that
> should not hurt non-gcc platforms.

The exports that aren't visible from "zlib.h" (like _tr_tally and such),
aren't that much a problem. If the attribute magic will add a big bunch
of #ifdefs, then I'd prefer to keep the headers/source clean and write a
simple "don't use" statement in the docs instead.

The problem is with macros like ZLIB_H, ZEXPORT, SYS16BIT, etc. that
aren't supposed to be relied on by users, but they leak out of "zlib.h".

> I can take a shot at a patch to eliminate the symbol leakge if you wish.

But you cannot avoid the public exposure of ZLIB_H, can you? And about
the other macros, adding a series of #undefs at the bottom of zlib.h is
unusual, and will incur a burden on maintenance. Did you have something
else in mind?

Best regards,
Cosmin