Re: environment variable conventions

[David Lee]

On Thu, 2 Sep 2004, Bob Friesenhahn wrote:

> On Thu, 2 Sep 2004, David Lee wrote:
> >
> > How should the incoming CPPFLAGS (from the user's environment) normally
> > interact with any being set in "configure".  My guess is that configure's
> > CPPFLAGS should modify (prepend? append?) any setting from the environment
> > rather than simply replace it.
>
> Any configure-script extension of user-configurable variables should
> allow user-provided values to prevail unless they interfere with
> package internals.  The user should always be in control but not so
> much that they shoot themselves in the foot.  Some configuration
> values should be prepended, and some should be appended.  To make
> things easier, most configuration items dealing with package internals
> should be incorporated in the package makefiles rather than configure.
>
> So, if the package has its headers in a subdirectory called "include",
> it must ensure that those headers are used rather than similar (maybe
> older) headers under /usr/local/include or in a path specified in
> CPPFLAGS.

Thanks for the reply.  Appreciated.

Do you know whether (and if so, where) these things are documented?
Whether they are classified as rules, recommendations, gentle advice etc.?
Differences across variables (e.g. "CC" would replace, "CPPFLAGS" would
normally prepend/append)?

This is so I can offer documented advice (or references to "community
conventions") to others in the project.


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