c - Core dumped when a function pointer is assigned with a funtion that has the same name in another file -

i abstract problem following scenario: 3 files:a.h,a.c,b.c,and code below:

a.c

#include "a.h" #include <stdio.h>  int (*call2)();  int call1(int (*cb)()){     call2=cb;     printf("success!");     return 1; } 

a.h

int call1(); 

b.c

#include <stdio.h> #include "a.h"  int call2(){return 0;};  int main(){     call1(call2); } 

then compiling these files gcc a.c b.c -o b warings:

/usr/bin/ld: warning: alignment 1 of symbol `call2' in /tmp/cc0wbcyh.o smaller 8 in /tmp/ccudjees.o /usr/bin/ld: warning: size of symbol `call2' changed 8 in /tmp/ccudjees.o 11 in /tmp/cc0wbcyh.o /usr/bin/ld: warning: type of symbol `call2' changed 1 2 in /tmp/cc0wbcyh.o 

then run './b'

segmentation fault (core dumped) 

my ideas: apparently, line call2=cb; has caused corrupt.that means,assigning function function pointer has same name wrong operation.i think reason relates how gcc compiler store function pointer , function.but not familiar implementing of gcc compiler. can me?

by defining , call2 2 different objects, 2 different types, have violated 1 definition rule. behaviour undefined.

to achieve behaviour want, declare both call2's static have internal linkage , don't conflict each other.