[libxml++] Ver. 2.6 vs 2.7 installation question

[Vladislav Grinchenko <3rdshift comcast net>]

Hi,

first off, thanks for writing and maintaining libxml++ - it greately
simplifies parsing XML files.

I have an app that used ver libxml++-0.26.0 till now on
Fedora Core 2 with libxml2-2.6.8.

The question I have is about a proper way of detecting
the version (and cflags/libs parms) of libxml++ installed.
Here's what I've discovered:

CASE 1) When libxml++ 0.26.0 is installed from an RPM package
packaged by Fedora Linux this is what's installed 

Name        : libxml++                     
Relocations :  (not relocatable)
Version     : 0.26.0                            
Vendor      : Fedora Linux
Release     : 0.fdr.3.rh90                 
Build Date  : Wed 12 Nov 2003 06:23:02 PM EST
Install Date: Thu 05 Aug 2004 11:03:28 PM EDT      
Build Host  : build-rh90
Group       : System Environment/Libraries   
Source RPM  : libxml++-0.26.0-0.fdr.3.rh90.src.rpm

installs these files:

/usr/lib/libxml++-0.1.so.12
/usr/lib/libxml++-0.1.so.12.0.0

Name        : libxml++-devel               
Relocations : (not relocatable)
Version     : 0.26.0                            
Vendor      : Fedora Linux
Release     : 0.fdr.3.rh90                  
Build Date  : Wed 12 Nov 2003 06:23:02  PM EST
Install Date: Thu 05 Aug 2004 11:03:29 PM EDT      
Build Host  : build-rh90
Group       : Development/Libraries         
Source RPM  : libxml++-0.26.0-0.fdr.3. 

installs these files:

/usr/include/libxml++-1.0
/usr/include/libxml++-1.0/libxml++/parsers
/usr/include/libxml++-1.0/libxml++/parsers/domparser.h
/usr/include/libxml++-1.0/libxml++/parsers/parser.h
/usr/include/libxml++-1.0/libxml++/parsers/saxparser.h

/usr/lib/libxml++-0.1.a
/usr/lib/libxml++-0.1.so
/usr/lib/pkgconfig/libxml++-1.0.pc

I have no problem with this installation because I can
get the vitals from 'configure.in' like so:


PKG_CHECK_MODULES(XMLCPP, libxml++-1.0 >= 0.26.0)
AC_SUBST(XMLCPP_CFLAGS)
AC_SUBST(XMLCPP_LIBS)

CASE 2) For non-RPM system, building libxml++-2.6.1 from a tarball:

% ./configure --prefix=/usr && make && make install

/usr/include
/usr/include/libxml++-2.6
/usr/include/libxml++-2.6/libxml++
/usr/include/libxml++-2.6/libxml++/parsers
             ...
/usr/include/libxml++-2.6/libxml++/parsers/parser.h
/usr/lib
/usr/lib/libxml++-2.6.so.1.0.1
/usr/lib/libxml++-2.6.so.1
/usr/lib/libxml++-2.6.so
/usr/lib/libxml++-2.6.la
/usr/lib/libxml++-2.6.a
/usr/lib/pkgconfig
/usr/lib/pkgconfig/libxml++-2.6.pc


CASE 3) For non-RPM system, building libxml++-2.7.0 from a tarball:

% ./configure --prefix=/usr && make && make install

libxml++-2.7.0
==============
                                                                                               
/usr/include
/usr/include/libxml++-2.6
/usr/include/libxml++-2.6/libxml++
/usr/include/libxml++-2.6/libxml++/parsers
/usr/include/libxml++-2.6/libxml++/parsers/parser.h
             ...
/usr/include/libxml++-2.6/libxml++/keepblanks.h
/usr/lib
/usr/lib/libxml++-2.6.so.1.0.2
/usr/lib/libxml++-2.6.so.1
/usr/lib/libxml++-2.6.so
/usr/lib/libxml++-2.6.la
/usr/lib/libxml++-2.6.a
/usr/lib/pkgconfig
/usr/lib/pkgconfig/libxml++-2.6.pc

------------------
DISCUSSION:

It seems that as far as pkg-config tool is concerned, the *.pc
file should have the same name in all 3 cases rather then

case 1 : /usr/lib/pkgconfig/libxml++-1.0.pc
case 2 : /usr/lib/pkgconfig/libxml++-2.6.pc
case 3 : /usr/lib/pkgconfig/libxml++-2.6.pc

Is there a problem with the way case 1 packages the files?
Should then name of PC file be libxml++2.6.pc in all 3 cases?

The installation itself is confusing too:

case 1 : /usr/include/libxml++-1.0
case 2 : /usr/include/libxml++-2.6
case 3 : /usr/include/libxml++-2.6

case 1 : /usr/lib/libxml++-0.1.so
case 2 : /usr/lib/libxml++-2.6.so
case 3 : /usr/lib/libxml++-2.6.so

Looks like there is no version difference between 2.6 and 2.7 ???
But according to http://libxmlplusplus.sourceforge.net/, 2.6 and 2.7
have different APIs but they suppose to work just fine with 
libxml2 >=2.6.1 and glibmm-2.4 >=2.4.0.

BTW, here is the place where I've got RPM from:
http://dag.wieers.com/packages/libxml++/

And this is THE ONLY place where I could get libxml++ RPMs from.
I wouldn't mind building my own RPM from a tarball, but for 
installations without development environment, this is out of
question. I should be able to point my users to some RPM repository
with sane properly built libxml++ RPMs.

Sounds like the RPM is wrong and for all libxml++-2.k.x where k >= 6,
they all should be identified as libxml++-2.6.pc and should
all install in $prefix/include/libxml++-2.6 and so forth.
Conclusively, 'configure.in' should test for:


PKG_CHECK_MODULES(XMLCPP, libxml++-2.6 >= 0.26.0)
AC_SUBST(XMLCPP_CFLAGS)
AC_SUBST(XMLCPP_LIBS)

The only problem I have with this approach is that it doesn't 
mirror libxml2's structure itself (but perhaps it shouldn't):


/usr/lib/libxml2.so.2
/usr/lib/libxml2.so.2.6.8
/usr/lib/libxml2.so

/usr/include/libxml2/libxml
/usr/include/libxml2/libxml/DOCBparser.h
/usr/include/libxml2/libxml/HTMLparser.h
/usr/include/libxml2/libxml/HTMLtree.h
/usr/include/libxml2/libxml/SAX.h
/usr/include/libxml2/libxml/SAX2.h
         ...
/usr/include/libxml2/libxml/xpointer.h

/usr/lib/pkgconfig/libxml-2.0.pc
/usr/lib/xml2Conf.sh
/usr/share/aclocal/libxml.m4

I'd like to hear your comments/suggestions,
-- Vlad
_____________________________________________________________
Vladislav Grinchenko       http://home.comcast.net/~3rdshift/
                                 e-mail: 3rdshift comcast net
                                                   
      Focus on quality, and productivity will follow.
_____________________________________________________________