I created a shared library "A" that use an other shared library "B".
I have a problem when I link my program with the shared library "A".
When I use some function from the other shared library ("B") inside cpp file of the shared library "A", all is fine.
But when I use these functions inside .h file (inside a templated method or an inlined method) of the shared library "A", the symbol is not loaded and I get an error "undefined reference to symbol".
I used g++ 7.2. I think the option -l forget to load the symbols used in header file.
Do you have an idea to avoid this?
Update 2:
Here a full reproducible example:
A.cpp
#include "A.h"
A.h
#ifndef A_H
# define A_H
#include <type_traits>
#include "B.h"
class A
{
public:
template <typename Type>
std::enable_if_t<std::is_arithmetic<Type>::value,void> funcA(Type value);
};
template <typename Type>
std::enable_if_t<std::is_arithmetic<Type>::value,void> A::funcA(Type value)
{
B tmp;
tmp.funcB(value);
}
#endif
B.cpp
#include "B.h"
#include <iostream>
void B::example()
{
std::cout << "works" << std::endl;
}
B.h
#ifndef B_H
# define B_H
class B
{
public:
void funcB(int value);
private:
void example();
};
inline void B::funcB(int value)
{
value += 1;
example();
}
#endif
main.cpp
#include "A.h"
int main()
{
A tmp;
tmp.funcA(5);
return 1;
}
Compile
g++ -std=c++17 -m64 -O2 -DNDEBUG -Wall -Wextra -Werror -fPIC -o A.o -c A.cpp
g++ -std=c++17 -m64 -O2 -DNDEBUG -Wall -Wextra -Werror -fPIC -o B.o -c B.cpp
g++ -std=c++17 -m64 -O2 -DNDEBUG -Wall -Wextra -Werror -fPIC -o main.o -c main.cpp
g++ -o libB.so B.o -shared
g++ -o libA.so A.o -shared -L. -lB
g++ -o application main.o -L . -lA
Error
main.o: In function `main':
main.cpp:(.text.startup+0x1a): undefined reference to `B::example()'
collect2: error: ld returned 1 exit status
Thank you,
SOLVED:
Finally, I solved my problem with this thread: GCC 4.5 vs 4.4 linking with dependencies
Thank you!