Benjamin Raverdy <b.raverdy@xxxxxxxxxxxx> writes: > I have a main application (lmApplication) (compiled with the -rdynamic > option) calling a dynamically shared lirbary, that is calling back > lmFromCaller() that belong to lmApplication. > lmApplication --------------------------------> lmLib.so > dyn load with dlopen | > | > LmFromCaller() <----------------------------------- > As I use rdynamic, that works fine. > > Now I want to do something similar, but having a shared library > lmPlugin.so instead of the main application. > Hence I have a main application (lmApplication) calling a dynamically > shared lirbary lmPlugin.so. > This plugin is itself calling another shared library lmLib.so that > calls the method LmFromCaller() of lmPlugin.so > > lmApplication --------> lmPlugin.so ------------------------> lmLib.so > dyn load with dlopen dyn load with dlopen | > | > lmFromCaller() <---------------------------- > > I get an error, spite I compiled everything with the -rdynamic option: > ./test: symbol lookup error: > /home/benjaminr/Desktop/example_dynamic_load/LmLib/Debug/liblmLib.so: > undefined symbol: _Z32lmFromCallerv > > If you would find it useful to understand my attempts, I can give you > the code and the way I compiled it. First step: use "readelf -s --wide" to look at the executable and the libraries, and find out where the symbol is defined. I assume you are passing RTLD_GLOBAL to both dlopen calls? If those ideas don't suggest anything, try setting LD_DEBUG=all in the environment before starting your program and examining the output around the point of the error. By the way, the -rdynamic option is not necessary when linking a shared library, only when linking an executable. But it should do no harm. Ian
