[Gdal-dev] porting of gdal to (optional) libtool build finally completed

[Alessandro Amici]

folks,

it has taken a good two months, but i'm finally ready to announce that the 
optional libtool build is now ready for prime time :).

this should allow setting proper soname versioning on all supported systems
and as a bonus we should be able to build standard shared libraries on a wide 
variety of previously unsupported unix and unix-like systems. 
in order to try it you just need to append '--with-libtool' to your normal 
configure command line.

in order to test system independece i built gdal on linux, cygwin and a 
cross-compile to mingw32.

on linux i could successfully test different combination of internal and 
external help libraries, in particular:
libz		ext/int
grass		not tested
cfitsio	ext
png		ext/int
libtiff		int
geotiff	int
jpeg		ext/int
gif		ext/int
ogdi		not tested
fme		not tested
hdf4		ext
jasper	not tested
ecw		not tested
kadaku	not tested*
mrsid		not tested
pg		ext
xerces	not tested
* judging form the GNUmakefile kadaku support is not going to work.

last but not least, i tested python support on linux-python2.3.

on cygwin i could verify that most of the raccomandation from Norman on how to 
build and install the libraries are actually automatically taken care by 
libtool.

the mingw32 host needs an annoying work-around (build with 'make LIBS=') in 
order to build the shared library. the static library is always built 
correctly.

now, i know that a few people on the list are no fan of libtool and they 
certainly have good reasons (like a 30% to 300% (!) increase in build time!).
OTOH moving the default build to libtool can simplify substantially the build 
infrastructure. and the portability advantages are also obvious.

a way to keep the advantages of using libtool without incurring in the worse 
disadvantages during development is to move the default build to libtool (so 
normal users will get that) and switch to the native build with a 
--without-libtool configure option (that will be used by developers).

since tha native build is targeted to developers (that is, mainly Frank and 
Andrey AFAIK) we can restrict it to only work on unix/linux with gnu build 
tools.

Frank, what's your opinion? isn't it tempting to support all unices with just 
one set of configure-makefile rules?

questions, comments and test report on other systems are welcome.

cheers,
alessandro