Soci as a static library on linux/ubuntu?

Question

I need to link a program statically with soci for security reasons.

I built the static libraries libsoci_core.a and libsoci_postgresql.a as my backend is postgresql.

My issue is that when I build my program with these libraries I get link errors.

[...]/lib/libsoci_core.a(backend-loader.cpp.o): In function `(anonymous namespace)::do_unload(std::basic_string, std::allocator > const&)':

backend-loader.cpp:(.text+0x623): undefined reference to `dlclose'

Looking at the code in backend-loader.cpp, it calls dlclose and other dynamic library loading functions.

So I am wondering if it is even possible to avoid these errors and have a 'true' static build.

Or what option should I use to not have this error and would the code call the static posgresql library?

thank you!

Answer 1

Since you are trying to build a statically linked library, the dl* functions need to be removed/stubbed out.

One way would be to create a dlstub.c file with your own functions and link them to the library.

Using prototypes from (/usr/include/dlfcn.h):

#include <dlfcn.h>

int    dlclose(void *){}
char  *dlerror(void){}
void  *dlopen(const char *, int){}
void  *dlsym(void *restrict, const char *restrict){}

Compile your stub functions into a *.o file, and link it to your compile command:

gcc -c -O2 -g dlstubs.c
gcc -static ...  -o dlstubs.o ...