Re: automake -vs- huge projects

[Alexandre Duret-Lutz]

>>> "Ralf" == Ralf Corsepius <address@hidden> writes:

 Ralf> On Tue, 2003-12-16 at 17:49, Tom Tromey wrote:
 >> The problem is, automake generates an explicit rule for each
 >> compilation.  Our resulting Makefile.in is nearly 9 megabytes.  This
 >> is really much too large -- compare to 200K with automake 1.4.

 Ralf> For subdir-compilation/non-recursive Makefiles automake generates *2*
 Ralf> explicit rules (cygwin and n/cygwin) for each compilation. Folding these
 Ralf> two rules into one, alone would reduce the size of Makefiles using many
 Ralf> files by almost factor 2.

Hmmm.  What we'd need to merge are these:

.c.o:
        $(CC) -c -o $@ $<
.c.obj:
        $(CC) -c -o $@ `$(CYGPATH_W) $<`

and these:

sub/foo.o: sub/foo.c
        $(CC) -c -o $@ `test -f 'sub/foo.c' || echo '$(srcdir)/'`sub/foo.c

sub/foo.obj: sub/foo.c
        $(CC) -c -o $@ `if test -f 'sub/foo.c'; then $(CYGPATH_W) 'sub/foo.c'; 
else $(CYGPATH_W) '$(srcdir)/sub/foo.c'; fi`


The extension is obviously not an issue, but how can we arrange the CYGPATH_W
stuff?   

I've thought about this:

.c.$(OBJEXT):
        $(CC) -c -o $@ $(am__cpbegin)$<$(am__cpend)
sub/foo.$(OBJEXT): sub/foo.c
        src=`test -f 'sub/foo.c' || echo '$(srcdir)/'`sub/foo.c; \
        $(CC) -c -o $@ $(am__cpbegin)$$src$(am__cpend)

and then have 
  am__cpbegin = `cygpath -w '
  am__cpend   = '`
or 
  am__cpbegin = '
  am__cpend   = '

but this is not really attractive.

A related question is why we need this `cygpath -w' stuff.
My understanding is that it is to turn special absolute
filenames such as /cygdrive/c/foo into c:\foo
(if this is true, then I think the first use of $(CYGPATH_W) in 
the sub/foo.obj rule is superfluous, since the file is relative)
so that compiler that do not understand cygwin filename can work.

Couldn't this be folded into a compiler wrapper script?
-- 
Alexandre Duret-Lutz