present but cannot be compiled (Was: autoconf-2.57 WARNING from AC_CHECK_HEADERS for X11/Xaw/Text.h)

[Akim Demaille]

Please, report this to the package maintainers, as it's a configure.ac
problem.  The Autoconf 2.57 doc says:

      Previous versions of Autoconf merely checked whether the header was
   accepted by the preprocessor.  This was changed because the old test was
   inappropriate for typical uses.  Headers are typically used to compile,
   not merely to preprocess, and the old behavior sometimes accepted
   headers that clashed at compile-time.  If you need to check whether a
   header is preprocessable, you can use `AC_PREPROC_IFELSE' (*note
   Running the Preprocessor::).
   
      This scheme, which improves the robustness of the test, also requires
   that you make sure that headers that must be included before the
   HEADER-FILE be part of the INCLUDES, (*note Default Includes::).  If
   looking for `bar.h', which requires that `foo.h' be included before if
   it exists, we suggest the following scheme:
   
   
   AC_CHECK_HEADERS([foo.h])
   AC_CHECK_HEADERS([bar.h], [], [],
   [#if HAVE_FOO_H
   # include <foo.h>
   # endif
   ])

Thanks!

| I'm getting this message when trying to test for any header file in X11/Xaw/
| checking X11/Xaw/Text.h presence... yes
| configure: WARNING: X11/Xaw/Text.h: present but cannot be compiled
| configure: WARNING: X11/Xaw/Text.h: check for missing prerequisite headers?
| configure: WARNING: X11/Xaw/Text.h: proceeding with the preprocessor's
| result
| configure: WARNING:     ## ------------------------------------ ##
| configure: WARNING:     ## Report this to address@hidden ##
| configure: WARNING:     ## ------------------------------------ ##
| checking for X11/Xaw/Text.h... yes
| 
| 
| 
| 
| This is from AC_CHECK_HEADERS with autoconf-2.57  on Solaris-8
| 
| I think X11/Intrinsic.h is a prerequisite.  I've  I have
| -I/usr/include/X11 in $CPPFLAGS
| but perhaps I need to do something else for prerequisites?
| 
| 
| 
| John Ellson
| 
| 
| 
|