[SOLVED] Creating object file from other dependent object files

Issue

my files dependencies a.c, a.h, b.c, b.h, c.c, c.h, are like that:

// a.c
#include "a.h"
#include "b.h"
#include "c.h"
#include <lib>

// b.c
#include "b.h"
#include <lib>

// c.c
#include "c.h"
#include <lib>

I have no main() function. I need to create out.o and someone else will use this with main in his program (he'll have to write #include "a.h" to use the functions I wrote there).

so I wrote

gcc -std=c99 -c c.c -o c.o -llib

gcc -std=c99 -c b.c -o b.o -llib

gcc -std=c99 -c a.c -o a.o -llib

but when I try to combine them using

gcc -o out.o a.o b.o c.o -llib

I get many errors like relocation 18 has invalid symbol index 13 and in the end undefined reference to 'main'.

How can I create what I need? `

Solution

I think you want to create a library out of your .o files.

ar crf yourlib.a a.o b.o c.o

then, other people can compile their programs by doing, for example:

gcc -o main main.c yourlib.a

Answered By - zsram

Answer Checked By - David Marino (WPSolving Volunteer)