DLL troubles

bar.c

#include <stdio.h>

extern const int answer;

extern __declspec(dllexport) void print42() {
    printf("Hello %d.\n", answer);
}

foo.c

__declspec(dllexport) const int answer = 42;

main.c

#include <stdio.h>

__declspec(dllimport) void print42();
__declspec(dllimport) const int answer;

int main() {
    printf("Hello %d. ", answer);
    print42();

    return 0;
}

Makefile

all: main.exe

foo.o: foo.c
	gcc -c foo.c -o foo.o
libfoo.a: foo.o
	ar sr libfoo.a foo.o

bar.o: bar.c
	gcc -c bar.c -o bar.o
libbar.dll: bar.o libfoo.a
	gcc -shared -o libbar.dll -Wl,--out-implib,libbar.dll.a bar.o -L. -lfoo

main.exe: main.c libbar.dll
	gcc -o main.exe main.c -L. -lbar