creating C++ libs contitionally

[Mattias Barthel]

Hello.

I am passing my Makefile.am's from 1.4 to 1.6.
Doing this I have encountered numerous incompatibility problems.

First when starting with 1.4, a part of the problem I bumped in to was 
that libtool did not really understand .dll as an extension of a lib,
me having to make the Makefiles compatible with Windows.

The libs for Windows could also not be dependent of cygwin even tough
the compiling environment was cygwin.

Also, beeing C++ code libraries I could not use the
AC_LIBTOOL_WIN32_DLL macro in configure.in because
it seems to be dependent of that the lib is
writtien in C.

Finally I succeded to create a Makefile.am that "worked"
in both environments except for a small warning from automake.
"automake: perl/Makefile.am: `vhcore.dll' is not a standard libtool 
library name"
But that was'nt really critical.

Here is one example that works for automake 1.4:
-------------------------------
AUTOMAKE_OPTIONS = foreign

basename = libbkswigptr

corename = $(basename)

INCLUDES = -I$(top_srcdir)/include -I$(PY_INC_DIR) -I.
CXXFLAGS = @CXXFLAGS@ -DSWIG_GLOBAL_MAPPING

includeswigdir = $(prefix)/include/vh/swig
includeswig_DATA = swigptr.swg

macropkglibdir = $(libdir)/$(MACRO_PACKAGE)

WANTED_LIBS = @WANTED_LIBS@

EXTRA_LTLIBRARIES = libbkswigptr.dll libbkswigptr.la
macropkglib_LTLIBRARIES = $(WANTED_LIBS)

libbkswigptr_dll_SOURCES = \
        bkswigptr.cpp

libbkswigptr_dll_LDFLAGS = -shared -avoid-version -lstdc++

libbkswigptr_la_SOURCES = $(libbkswigptr_dll_SOURCES)

libbkswigptr_la_LDFLAGS = -avoid-version -lstdc++

CLEANFILES = *~

if INST_HOOK
CXXLINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) $(LDFLAGS) -o $(WANTED_LIBS)
else
CXXLINK = $(LIBTOOL) --mode=link $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) 
$(LDFLAGS) -o $@ -rpath $(macropkglibdir)
endif

MAINTAINERCLEANFILES = Makefile.in
------------------------------------------------------------------------------
INST_HOOK is a AM_CONDITIONAL which decides the type of linking
to be used in wether cygwin or Linux. Because libtool does not 
understand C++ linking for Windows I am overriding CXXLINK in that case.

Changing some stuff in this Makefile.am I got it through automake 1.6 
but now it doesn't compile.
New Makefile.am:
------------------------------------------------------------------------------

AUTOMAKE_OPTIONS = foreign

basename = libbkswigptr

corename = $(basename)

INCLUDES = -I$(top_srcdir)/include -I$(PY_INC_DIR) -I.
CXXFLAGS = @CXXFLAGS@ -DSWIG_GLOBAL_MAPPING

SOURCES = bkswigptr.cpp

if INST_HOOK
MYLINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) $(LDFLAGS) -o $(WANTED_LIBS)
else
MYLINK = $(LIBTOOL) --mode=link $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) 
$(LDFLAGS) -o $@
endif

CXXLINK = $(MYLINK)

includeswigdir = $(prefix)/include/vh/swig
includeswig_DATA = swigptr.swg

macropkglibdir = $(libdir)/$(MACRO_PACKAGE)

WANTED_LIBS = @WANTED_LIBS@

EXTRA_LTLIBRARIES = libbkswigptr.la libbkswigptr.dll
macropkglib_LTLIBRARIES = $(WANTED_LIBS)

libbkswigptr_la_SOURCES = bkswigptr.cpp

libbkswigptr_la_LDFLAGS = -avoid-version -lstdc++ -rpath $(macropkglibdir)

libbkswigptr_dll_SOURCES = $(libbkswigptr_la_SOURCES)

libbkswigptr_dll_LDFLAGS = -shared -avoid-version -lstdc++

libbkswigptr_dll_CXXFLAGS = $(AM_CXXFLAGS)

CLEANFILES = *~

MAINTAINERCLEANFILES = Makefile.in
-------------------------------------



The question is, why does the Makefile
generated from the new Makefile.am not compile?

See output:
------------------------------------------------------------------------------

$ make
source='bkswigptr.cpp' object='bkswigptr.lo' libtool=yes \
depfile='.deps/bkswigptr.Plo' tmpdepfile='.deps/bkswigptr.TPlo' \
depmode=none /bin/sh ../config/depcomp \
/bin/sh ../libtool --mode=compile g++ -DHAVE_CONFIG_H -I. -I. 
-I../config -I../include -I -I.    -g -O2 -DSWIG_GLOBAL_MAPPING -c -o 
bkswigptr.lo `test -f 'bkswigptr.cpp' || echo './'`bkswigptr.cpp
/bin/sh ../libtool --mode=link g++  -g -O2 -DSWIG_GLOBAL_MAPPING  -o 
libbkswigptr.la  -avoid-version -lstdc++ -rpath /tmp/lib/vh bkswigptr.lo
mkdir .libs
rm -fr .libs/libbkswigptr.la .libs/libbkswigptr.* .libs/libbkswigptr.*
(cd . && ln -s bkswigptr.lo bkswigptr.o)
gcc -shared  bkswigptr.lo  -lstdc++  -Wl,-soname -Wl,libbkswigptr.so -o 
.libs/libbkswigptr.so
gcc: bkswigptr.lo: No such file or directory
make: *** [libbkswigptr.la] Error 1
-------------------------------------------------------------------------------


Thanks in advance,

Mattias
--
Mattias Barthel, Software Engineer
CapGemini at Hewlett Packard
Tel. 34 93 582 26 02
E-mail: address@hidden