Re: Disable the present-but-cannot-be-compiled header warning?

[Paolo Bonzini]

Jeff Squyres wrote:
> Is there a way to disable the present-but-cannot-be-compiled header
> warning from AC_CHECK_HEADERS in AC 2.61?  I don't see any mention of
> disabling this warning in either the "Header Present But Cannot Be
> Compiled" or "Generic Header Checks" sections in the 2.61 docs.
> 
> I ask because we added some AC_CHECK_HEADERS into our configure.ac
> specifically because we know that there are systems out there that have
> uncompilable headers with some compilers (e.g., some kernel header files
> don't play nicely with non-gnu compilers in 32 bit mode).
> 
> All we want is a HAVE_<foo>_H macro (or not) -- our source code can
> react as appropriate (e.g., we can disable the feature that requires the
> <foo> header file).  Specifically: we *don't* want users to report this
> to our mailing list every time it happens:

You should use four-arguments AC_CHECK_HEADERS.  Pass
AC_INCLUDES_DEFAULT as the fourth argument if you want to filter out
headers that cannot be compiled; pass [-] if you don't want that.

This is undocumented, I admit.

Paolo