Re: Detecting that AC_PROG_LIBTOOL has been invoked

[Paolo Bonzini]

> The reason why I'm asking this is that I wrote some macros that rely on 
> Libtool's magic handling of -R and even though it's clearly stated in 
> the doc/comments/README that Libtool is mandatory, people keep running 
> in troubles because they didn't use Libtool, so I'd like to trigger an 
> error, somehow, to tell them that they did something wrong.

You can use m4_provide_if like this:

m4_define([m4_provided], [
m4_provide_if([AC_PROG_LIBTOOL], [], [
m4_provide_if([LT_INIT], [],
              [m4_warn([syntax], [Libtool required by $1])])])])])

...

m4_provided([MY_MACRO_NAME])

I didn't count the number of closing brackets.

Paolo