problems with makefile

Hello,

I have some problems writing my makefile. I'm newbie writing makefiles because I use to make small programs. I have defined a library, functions.h and functions.c that uses the GNU scientific library. And then a program that calls functions from functions.h. My makefile is like this:

Code:

---


SDIR                =        source directory

CC                =        gcc
CFLOPTS                =        -g
CFLAGS                =        $(CFLOPTS) -I$(SDIR)

CPROGS                =        main

OBJETOS                =        $(SDIR)/main.o $(SDIR)/funciones.o

all:$(CPROGS) $(OBJETOS)


clean:
        rm -f *.o $(CPROGS)


main_RCS:$(OBJETOS)
        $(CC) $(CFLAGS) -o $@ $(OBJETOS) -lm
        mv $@ $(SDIR)

funciones_RCS.o:$(SDIR)/funciones.c $(SDIR)/funciones.h
        $(CC) $(CFLAGS) /usr/local/lib/libgsl.a -o $@ -lm
        mv $@ $(SDIR)

main_RCS.o:$(SDIR)/main.c $(SDIR)/funciones.h
        mv $@ $(SDIR)

---

I have an error of undefined reference in every gnu scientific library function that I use. Someone can help me?

Looks to me like you are not linking with the scientific library when producing the final program (main_RCS).

--
Mats

But the final program doesn't use scientific library functions, it only calls one function from funciones.c

Quote:

---

Originally Posted by bartleby84

But the final program doesn't use scientific library functions, it only calls one function from funciones.c

---

Yes, but you are not linking functiones.o with a libray until you link it together into the final executable. When you compile the "half-way-step", it will just produce an object file of the C file, and not do any linking.

If you add -v to the CFLOPTS variable, you will see exactly what the compiler does (which is quite a bit). You should only see a "collect2" stage in the final linking step, which is the target here:
main_RCS:$(OBJETOS)

If you see collect2 elsewhere, then you have something else wrong (and it may be that you need a -c on the cases where you produce .o files - without seeing the actual output of what make does when you run it, I can't say for sure if it does the right thing or not).


--
Mats

Ok thanks, I'm going to try that!