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Re: cpplib: Dump __GXX_WEAK__ and __STDC__ with -dM

Kaveh R. Ghazi writes:

>  > From: Rainer Orth <ro@TechFak.Uni-Bielefeld.DE>
>  > 
>  > Like Zack, I'm not sure this special treatment of Solaris 2 is a good idea.
>  > Reducing the number of copies system headers may somewhat reduce the
>  > breakage caused by inconsistencies between the system headers on the host
>  > gcc is run on versus the fixinclded headers, but it cannot eliminate it,
>  > but may just give a false sense of security.  On the other hand, I have
>  > just been bitten by Digital UNIX V4.0B fixincluded headers on a V4.0F
>  > system and the resulting breakage, so avoiding changes to system headers
>  > has important advantages.
> And its not just OS *upgrades*.  On Solaris it has been the case that
> OS *patches* sometimes also install new copies of system headers to
> correct various problems.  If that header was "fixed" by the gcc
> bootstrap prior to the patch installation, gcc will never see the
> correction.

True, but this in no way specific to Solaris patches: the same thing
happens regularly on IRIX and Tru64 UNIX as well, and still fixincludes is
fully run on those platforms.  Thus my argument that even if not running
the STDC_0 fixes and relying on the STDC_0_IN_SYSTEM_HEADERS hack, OS
patches may break headers fixed by fixincludes, on Solaris as well as on
other platforms.  When fixincludes wasn't run on Solaris at all, the
STDC_0_IN_SYSTEM_HEADERS stuff was sufficient and thus valuable, now when
fixincludes is run against a considerable number of OS headers, it's
benefit is reduced and should be weighted against maintenance costs and
special-casing one particular platform.


Rainer Orth, Faculty of Technology, Bielefeld University

Email: ro@TechFak.Uni-Bielefeld.DE

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