Weak-linking with static libraries
- by Jaakko L.
I have declared an external function with a GCC weak attribute in a .c file:
extern int weakFunction( ) __attribute__ ((weak));
Compiled object file has weakFunction defined as a weak symbol.
Output of nm:
1791: w weakFunction
I am calling the weak defined function as follows:
if (weakFunction != NULL)
{
weakFunction();
}
When I link the program by defining the object files as parameters to GCC (gcc main.o weakf.o -o main.exe) weak symbols work fine. If I leave the weakf.o out of linking, the function address is NULL in main.c and the function won't be called.
Problem is, when weakf.o is inside a static library, for some reason the linker doesn't find the function and the function address always ends up being NULL.
Static library is created with ar: ar rcs weaklibrary weakf.o
Anyone had similar problems?
