Re: ac_executable_extensions

[Tim Van Holder]

> autoconf-2.54c generated configure scripts that use 
> AC_PATH_PROG contain
> this line:
> 
> for ac_exec_ext in '' $ac_executable_extensions; do
> 
> but ac_executable_extensions is never set. A bit useless, isn't it?
> Shouldn't there be a macro _AS_DOS or so which sets 
> ac_executable_extensions
> and which is REQUIREd by AC_PATH_PROG?

The idea is that something like that is added at some point.
The trick is doing this correctly WITHOUT using any platform-specific
tests (IIRC Akim wants to keep autoconf as generic as possible).
Since there is no real good test to find out which extensions are
considered 'executable', this is left to config.site for now.

For example, the DJGPP port of autoconf comes with a config.site
that sets ac_executable_extensions to ".bat .exe" as those are
most commonly used (with a comment that .com, .sh, .btm, .pl etc
can be added if needed).
Frankly this seems enough for now, as there are very few platforms
that need to worry about it; any code added to autoconf to automate
the setting of this variable must be certain not to break any other
platforms.