Re: AC_CHECK_HEADER, autoconf 2.57, includes problem

[Raja R Harinath]

Hi,

Bill Schottstaedt <address@hidden> writes:

> My apologies if this has already been reported.
>
> In autoconf 2.57 in AC_CHECK_HEADER, I think the gcc -E conftest
> check for header usability needs to include the default includes
> from the header presence test.  In my case,
>
>         OLD_CFLAGS="$CFLAGS"
>         CFLAGS="-I/usr/local/include/gtkglext-1.0
>         -I/usr/local/lib/gtkglext-1.0/include $GTK_CFLAGS $CFLAGS"

This is the actual bug, and it's in your configure.in.  Set CPPFLAGS
instead.

> checking gtk/gtkgl.h usability... yes
> checking gtk/gtkgl.h presence... no
> configure: WARNING: gtk/gtkgl.h: accepted by the compiler, rejected by the 
> preprocessor!
> configure: WARNING: gtk/gtkgl.h: proceeding with the preprocessor's result
> configure: WARNING:     ## ------------------------------------ ##
> configure: WARNING:     ## Report this to address@hidden ##
> configure: WARNING:     ## ------------------------------------ ##
> checking for gtk/gtkgl.h... no

A red herring.  GIGO ;-)  But, the warning does contain a hint that
the compiler and the preprocessor may be seeing things -- like search
paths -- differently.

- Hari
-- 
Raja R Harinath ------------------------------ address@hidden