Re: Check if a macro has already been defined with AC_DEFINE

[Bob Friesenhahn]

On Fri, 30 Aug 2019, Quaquaraqua wrote:

> Hi there,
> how can we check if a macro has been previously defined with AC_DEFINE ?
>
> For instance, something like the following piece of code:
>
> AX_OPENMP dnl it sets AC_DEFINE(HAVE_OPENMP,1) in case of success
> ...
> m4_ifdef([[HAVE_OPENMP]], dnl how to check if HAVE_OPENMP has been defined?
>    [ ... do something ... ],
>    [ ... do something else ... ]
> )
>
> I'm aware that, as workaround, AX_OPENMP can take two optional arguments, 
> ACTION-IF-FOUND and ACTION-IF-NOT-FOUND but I am
> restricted to use them atm.

It seems that cached test results are normally stored in variables of 
the form "ac_cv_have_FOO".  Check the generated config.status script 
for the exact name to test.

Bob
--
Bob Friesenhahn
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