A sample nmake project

main.c

#include <stdio.h>
#include "share1.h"
#include "share2.h"
#include "static.h"

int main() {
    printf("hello world\n");
    int a = 4;
    int b = 2;
    printf ("a: %d, b: %d\n", a, b);
    printf("add: %d\n", add(a, b));
    printf("sub: %d\n", sub(a, b));
    printf("mul: %d\n", mul(a, b));
    printf("div: %d\n", div(a, b));
    return 0;
}

makefile

shared_library: share1.c share2.c
	cl /c share1.c share2.c
	link share1.obj share2.obj /dll /out:share.dll /implib:share.lib

static_library: static.c
	cl /c static.c
	lib static.obj /out:static.lib

all: shared_library static_library main.c
	cl /c main.c
	link main.obj share.lib static.lib

clean:
	del /F /Q *.exe *.dll *.lib *.obj *.exp

share1.c

#include "share1.h"

int add(int a, int b) {
    return a + b;
}

share1.h

#ifndef SHARE1_H
#define SHARE1_H

__declspec(dllexport) int add(int, int);

#endif /* SHARE1_H */

share2.c

#include "share2.h"

int sub(int a, int b) {
    return a - b;
}

share2.h

#ifndef SHARE2_H
#define SHARE2_H

__declspec(dllexport) int sub(int, int);

#endif /* SHARE2_H */

static.c

#include "static.h"

int mul(int a, int b) {
    return a * b;
}

int div(int a, int b) {
    return a / b;
}

static.h

#ifndef STATIC_H
#define STATIC_H

__declspec(dllexport) int mul(int, int);
__declspec(dllexport) int div(int, int);

#endif /* STATIC_H */