Re: Why does gnulib use makefile rules rather than configure?

[Paul Eggert]

On 9/8/19 2:06 PM, Paul Smith wrote:
> Why can't we add
> these headers as AC_CONFIG_FILES() and allow them to be generated by
> the configure script, instead of requiring makefile rules to do it?

Makefile rules can do things that an Autoconf substitition can't, or at least 
can't do easily. For example, the arpa_inet module (the 2nd one I looked at in 
response to your email) doesn't merely substitute; it also copies three files' 
contents into lib/arpa_inet.h.

Typically 'make' beats 'configure' to do this sort of thing, since 'make' is 
more powerful - e.g., it can run in parallel.

Admittedly GNU Make is a special case, since you want to build it without having 
'make'. And if it's just a few Gnulib modules and they're not doing anything 
fancy, perhaps we can modify the modules to use 'configure' substitutions 
instead of 'make' rules. On the other hand perhaps it's time to stop worrying 
about building GNU make without a 'make'. We don't worry that GCC can't be built 
on a system without a C compiler, so why worry about building GNU Make on a 
system without 'make'?