Why I'm not getting "Multiple definition" error from the g++?
- by ban
I tried to link my executable program with 2 static libraries using g++. The 2 static libraries have the same function name. I'm expecting a "multiple definition" linking error from the linker, but I did not received. Can anyone help to explain why is this so?
staticLibA.h
#ifndef _STATIC_LIBA_HEADER
#define _STATIC_LIBA_HEADER
int hello(void);
#endif
staticLibA.cpp
#include "staticLibA.h"
int hello(void)
{
    printf("\nI'm in staticLibA\n");
    return 0;
}
output:
g++ -c -Wall -fPIC -m32 -o staticLibA.o staticLibA.cpp                                                                             
ar -cvq ../libstaticLibA.a staticLibA.o                                                                                                                           
a - staticLibA.o 
staticLibB.h
#ifndef _STATIC_LIBB_HEADER
#define _STATIC_LIBB_HEADER
int hello(void);
#endif
staticLibB.cpp
#include "staticLibB.h"
int hello(void)
{
    printf("\nI'm in staticLibB\n");
    return 0;
}
output:
g++ -c -Wall -fPIC -m32 -o staticLibB.o staticLibB.cpp 
ar -cvq ../libstaticLibB.a staticLibB.o 
a - staticLibB.o
main.cpp
extern int hello(void);
int main(void)
{
 hello();
 return 0;
}
output:
g++ -c  -o main.o main.cpp
g++ -o multipleLibsTest main.o  -L. -lstaticLibA -lstaticLibB -lstaticLibC -ldl -lpthread -lrt