libraries and the build system

[tridge at samba.org]

Daniel,

 > Are there any architectural issues that would prohibit Samba from using
 > Libtool? If so, would it be possible to work with Libtool developers to
 > resolve those issues?

Every time I download a package and find it uses libtool I get a "oh
no, not again" feeling. I've just had far too many bad experiences
with libtool, especially when something mysterious goes wrong and
debugging it is invariably a nightmare.

If we wanted something like libtool then I would write a new one that
works like this:

 - during configure it would work out what strategy is needed for the
   various compile/linking tasks on this platform.

 - this strategy would be returned in the form of a string, a bit like
   the config.guess output, but oriented to compiler/linker type.

 - the strategy strings would be chosen from a set of known
   strategies. Internally each strategy would have a test component
   that tests if that strategy string works. 

 - at configure time each strategy is tested until one is found that
   works. There would be an internal ordering of the strategy strings
   so the most functionally advanced strategies would be tried first.

 - the tool would then take this string as input for further
   operations, but not actually _do_ any of the compile/link
   operations itself, it would instead return the commands needed, in
   the form of make rules.

 - these resulting make rules would be placed in the Makefile

 - normal "make" will then do the actual compile/link/install, but
   without need for any further calls to the tool

So the tool would essentially be a "discovery" tool, that knows how to
work out appropriate build rules for a platform. It would not be a
tool that attempts to actually do the work. This makes it debuggable,
as you get a normal Makefile, that programmers know how to edit.

Cheers, Tridge

PS: If someone knows of a tool that already works like this then
please let me know. If the answer is "you can make libtool do this"
then I'm not interested. I've been burnt too often.