What could cause the compiler to return the error " undefined reference to `Print' " ?

Question

I've been working on this simple C project, trying to implement header, implementation, and makefiles. My professor provided the code for us to test, however whenever I use the "make hello3" command, the compiler gives me the error "undefined reference to `Print' " (Print is the name of the function trying to be implemented). Bellow are the files I've been working with.

Functions.h

#include <stdio.h>

void Print(char *str);

Functions.c

#include "Functions.h"

void Print(char *str)

{

printf("%s\n", str);

}

hello3.c

#include "Functions.h"

int main(int argc, char **argv)

{

char *myString="Hello, world!";

Print(myString);

return 0;

}

My Makefile

CC=gcc

OBJS=*.o

PROGS= hello3

INCS= -I.

hello3.o: hello3.c Functions.h

${CC} -c hello3.c

hello3: hello3.o Functions.o

${CC} hello3.o Functions.o -o hello3

Functions.o: Functions.c Functions.h

${CC} ${INCS} -c Functions.c

clean:

rm ${OBJS} ${PROGS}

Answer 1

A couple nits about the Makefile:

1) make uses parenthesis around variable names, shell uses curly brackets.

2) Your spacing does seem to be off, double check that.

3) You do not need a "hello3.o" target: this is redundant with the hello3 executable. Just remove it and the reference to it in the hello3 target.

Otherwise things look more or less correct. Try walking through this manually:

gcc -c Functions.c

gcc Functions.o hello3.c -o hello3

Answer 2

Check your spacing; Makefiles are notorious over how things are tabbed. If the above is an accurate representation of your Makefile, its possible it doesn't like the double tab. Check your directory, is there a Functions.o file?