[Gdal-dev] GNU make build system update

[Alessandro Amici]

uff!

> i could try libtool support on a couple more targets:
> cygwin -> only the static library are produced by libtool and i get a
> strange warning about possibly unresolved symbols (?)
> mingw -> same as cygwin
> cross-compile for mingw from linux -> apparently same as mingw
>
> any win32 guru can help me on those?

after having spent a fair bit of time on the binutils man pages and having 
tried various combinations of tricks, i found out that the following rule 
builds static _and_ shared libraies on my mingw cross-compile environment:

$(LIBGDAL):	$(GDAL_OBJ:.o=.lo)
	$(LD) -o $@ $^ \
	    -rpath $(INST_LIB) \
	    -no-undefined \
	    -version-info $(LIBGDAL_CURRENT):$(LIBGDAL_REVISION):$(LIBGDAL_AGE)

we need the -no-undefined option _and_ to remove $(LIBS).
i need a bit more time in order to check for the correct way to implement the 
configure changes, thou.

unfortunately, however, this is not the end of the story :(.
trying that on a live mingw environment the build exploded on an unexpected 
'ld -r' with the same problem we had a few weeks ago.

after some more digging into the configure scripts this second problem appears 
to be related to the 8k limit on the command size lenght on windows! our 
command line is about 11k in size (!) and libtool trys to build the shareded 
library picewise with the help of a few 'ld -r' before the big 'g++ -shared'.

umpf!

i didn't find a sane workaround for this up to now.

cheers,
alessandro