Thread: Undefined Reference to Existing Library

I have to solve something in C for school, but I'm stuck and I can't solve this problem.

I have this .c file where I call a function

Code:

lista = lista_criar(free);

The function "lista_criar" is defined in "listas.h" and "listas.c".
I have the include in the source file (#include "listas.h") and this header is in the same directory as the source, but when I try to compile i get this error:

Code:

cc -o prog main.o debug.o  
main.o: In function `main':
/home/sparkt/PA/Ficha3/ex3/main.c:79: undefined reference to `lista_criar'
collect2: ld returned 1 exit status
make: *** [prog] Error 1

I also modified my makefile to this:

Code:

(...)

#Dependencies
main.o: main.c debug.h listas.h listas.c #${PROGRAM_OPT}.h
${PROGRAM_OPT}.o: ${PROGRAM_OPT}.c ${PROGRAM_OPT}.h

debug.o: debug.c debug.h
semaforos.o: semaforos.c semaforos.h

(...)

And still can't compile the code :s
Hope someone can help me figure out what I'm missing!
Thanks in advance!

If your function is in listas.c, you need to compile that file too.

Originally Posted by tabstop

If your function is in listas.c, you need to compile that file too.

I have listas.c and listas.h... I've added both to the makefile because i'm new to using makefiles and i was not sure what to add...

I'm not sure I understand... I should compile listas.c and main.c somehow "together"?

One more thing i've remembered, listas.h as a structure defined too, and i don't get any error while using the structure... the compiler recognizes it.
But I do get that error when i call the lista_criar() function...

I guess i've figured it out... I've also edited this line in the makefile

Code:

PROGRAM_OBJS=main.o debug.o listas.c

Seems like it's compiling listas.c like you said and not giving me that error!
Thanks!