unresolved symbols with libltdl at runtime

[Philip Lowman]

I am having a problem with libltdl version 1.5.22 (Ubuntu 6.06) that I 
am not having with libltdl version 1.5.16 (Fedora Core 4), and I'm not 
sure why.  At runtime my program runs into unresolved symbols and 
crashes in the middle of running because it can't find a particular 
symbol which exists in a plugin which is being loaded by libltdl (as far 
as I can tell).  The weird thing is this problem doesn't occur in Fedora 
Core 4 but I don't know why.  I'm using version 1.9 of the GNU Autotools 
on both systems and slightly different versions of GCC (4.0.2 vs. 
4.0.3).  The error I get occurs when one of the plugins makes a call 
into a dependent plugin.

libpluginConfigFileSymbology depends on a call to libpluginSymbologyManager.

/home/lowmanp/src/mpv-1.5.2+stuff.ubuntu/kernel/.libs/lt-mpv: symbol 
lookup error: 
./pluginConfigFileSymbology/.libs/libpluginConfigFileSymbology.so.0: 
undefined symbol: _ZN16SymbologyManager13lookup_symbolEiR10SymbolType\

An nm on libpluginConfigFileSymbology.so.0 shows the symbol is 
unresolved (as I'm assuming it should be).  The symbol is defined in the 
SymbologyManager library, I just can't figure out why it's not being found.

nm .libs/libpluginConfigFileSymbology.so |grep lookup_symbol
         U _ZN16SymbologyManager13lookup_symbolEiR10SymbolType
nm .libs/libpluginSymbologyManager.so |grep lookup_symbol
00002ea8 T _ZN16SymbologyManager13lookup_symbolEiR10SymbolType

I am using the LTDL_LIBRARY_PATH environment variable with a script to 
search for and help assist in loading all of the plugins.  I'm fairly 
certain this isn't the problem though because if I do a "make install" I 
get the same runtime error running out of /usr/bin.

Here are my Makefile.am's for the two plugins.  I tried removing 
"-no-undefined" from the two plugins but it didn't help.  Not sure what 
to try from here.

pluginSymbologyManager
======================
lib_LTLIBRARIES = libpluginSymbologyManager.la

libpluginSymbologyManager_la_SOURCES = \
    PluginSymbologyManager.cpp\
    PluginSymbologyManager.h\
    pluginWrapper.cpp\
    pluginWrapper.h\
    SymbologyManager.cpp\
    SymbologyManager.h

libpluginSymbologyManager_la_LIBADD = \
    -L$(top_builddir)/common -lmpvcommon \
    -lfl @CCL_LIBS@ -lpthread

#DEFS += -DWIN32

INCLUDES = \
    -I$(top_srcdir)/common \
    -I$(top_srcdir)/pluginSymbologyBase \
    -I$(top_srcdir)/pluginRenderSymbologyOSG \
    @CCL_CFLAGS@

libpluginSymbologyManager_la_LDFLAGS = \
        -module\
        --debug\
        -no-undefined

pluginConfigFileSymbology
======================
lib_LTLIBRARIES = libpluginConfigFileSymbology.la

libpluginConfigFileSymbology_la_SOURCES = \
    PluginConfigFileSymbology.cpp\
    PluginConfigFileSymbology.h\
    pluginWrapper.cpp\
    pluginWrapper.h\
    VrsgSymbologyParser.cpp\
    VrsgSymbologyParser.h

libpluginConfigFileSymbology_la_LIBADD = \
    -L$(top_builddir)/common -lmpvcommon \
    -lfl @CCL_LIBS@ -lpthread

#DEFS += -DWIN32

INCLUDES = \
    -I$(top_srcdir)/common \
    -I$(top_srcdir)/pluginSymbologyBase \
    -I$(top_srcdir)/pluginSymbologyManager \
    @CCL_CFLAGS@

libpluginConfigFileSymbology_la_LDFLAGS = \
        -module\
        --debug\
        -no-undefined