RE: error: '' is already registered with AC_CONFIG_FILES

[Stephen Henry]

It would appear that altering the code into two AC_CONFIG_FILE statements 
worked. Thank you for the help. I'll up to the later version of m4 too.

Thanks,
Steve

-----Original Message-----
From: Eric Blake [mailto:address@hidden 
Sent: Friday, April 08, 2011 11:17 AM
To: Stephen Henry
Cc: address@hidden
Subject: Re: error: '' is already registered with AC_CONFIG_FILES

On 04/08/2011 12:01 PM, Stephen Henry wrote:
> 
> The construct in which this error appears is:
> 
> AS_IF([test...],
> [AC_CONFIG_FILES([
>       ... list of Makefiles in various directories
>       [AS_IF([test...],
>                [makefile1.am
>                 makefile2.am
>                 makefile3.am])]
>       ])
> ])

Try swapping your conditionals.  AC_CONFIG_FILES expects literal file names, 
but the text "[AS_IF..." is not a literal filename.  Meanwhile, it is safe to 
call AC_CONFIG_FILES more than once.

AC_CONFIG_FILES([... list of unconditional makefiles]) AS_IF([test...],
  [AC_CONFIG_FILES([makefile1.am makefile2.am makefile3.am])])

> 
> I have verified that the list does not contain duplicate Makefile entries. 
> The configuration script works fine when I remove the [AS_IF] statement, but 
> not when it is included. I am fairly confident that the syntax used is 
> correct and I have removed all trailing whitespace etc... Also, all of the 
> Makefiles have been verified to be in UNIX format.
> 
> I am using autoconf 2.68 and m4 1.4.15.

Consider upgrading to m4 1.4.16; there was a nasty strstr() bug in m4
1.4.15 that has been proven to generate broken configure files in some cases.

-- 
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org