Re: nesting of AC_CHECK_PROG ?

[Stepan Kasal]

Hi,
  you mailed your problem to both autoconf and automake lists.
I think it's pure autoconf question. so we should not continue with the
discussion on the automake list.

On Tue, Oct 19, 2004 at 01:40:05PM -0400, Yasunari Tosa wrote:
> I appreciated it very much that AC_CHECK_LIB can be nested as
> 
> AC_CHECK_LIB([tlc],[Tcl_Init], [LIB_TCL=-ltcl],
>     [ AC_CHECK_LIB([tcl8.4], [Tcl_Init], [LIB_TCL=-ltcl8.4],
>           [AC_MSG_ERROR("FATAL: libtcl not found")] )
>     ])

When you look at it closer, you see that the third and fourth parameter
of AC_CHECK_LIB contain shell code (the manual uses the term ``action'').
Of course, you can place there a macro which expands to shell code.

> Unfortunately AC_CHECK_PROG() nesting does not work:
> 
> AC_CHECK_PROG([TIXWISH], [tixwish],[tixwish],
>     [ AC_CHECK_PROG([TIXWISH], [tixwish8.1.8.3], [tixwish8.1.8.3],
>          [AC_MSG_ERROR("FATAL: tixwish cannot be found")])
>     ])

The third and fourth parameter of this macro is a _value_ which would
be assigned to the variable.  You cannot put there shell code or
a macro which expands to shell code.

Hope this explains it.

Stepan Kasal