I've compiled shared library (pppd plugin) with no errors or warnings but when pppd tries to load this plugin, it fails with "undefined symbol g_string_sized_new" message.
Plugin source can be found here: https://raw.github.com/openshine/ModemManager/master/test/mm-test-pppd-plugin.c
To compile shared library I use the following commands:
gcc -fPIC -c ./mm-test-pppd-plugin.c -o mm-test-pppd-plugin.o `pkg-config --cflags --libs glib-2.0`
gcc -shared -o ./mm-test-pppd-plugin.so ./mm-test-pppd-plugin.o
As I find this g_string_sized_new should be in GLib. So as I understand it should be available systemwide?
OS: Ubuntu 13.04
Any ideas what could be wrong? Thanks in advance!
Compilation is not linkage and linkage is not compilation.
On the first line, you are invoking the compiler so as to compile your C source text into object code. Here supplying the --libs flag to pkg-config is completely superfluous, pure compiler can do nothing with libraries.
However, on the second line, you are trying to link the resulting object files into a proper executable using the linker, but now you are missing the pkg-config --libs from the end of the command line - the linker needs to know the libraries to be linked against in order it to be able to resolve symbols.