Question

I wanted to write a makefile for a program that has source files located in different directories, the structure is:

--root(here will be makefile)    
  --src:
    --main.c
    --include:
      --here are 6 .h files, that are used by other .c files, main.c includes on all of them
    --operacje
      --suma.c
      --iloczyn.c
      --roznica.c
    --reszta:
      macierz.c
    --we_wy:
      --rest of the .c files

most of .c files include at least one .h file. This is what I wrote so far:

VPATH=./src:./src/include:./src/operacje:./src/reszta:./src/we_wy
CLFAGS = -Wall
CC = gcc
INCLUDE = -I src/include
NAME = macierze

FILE_SOURCE := pliki.c wczytaj_plik.c wypisz_plik.c
CONSOLE_SOURCE := wczytaj_konsola.c wypisz_konsola.c
OTHER_SOURCE := suma.c roznica.c iloczyn.c macierz.c
HEADERS := suma.h roznica.h iloczyn.h wypisz.h wczytaj.h macierz.h

FILE_OBJECTS := $(FILE_SOURCE:.c=.o)
CONSOLE_OBJECTS := $(CONSOLE_SOURCE:.c=.o)
OTHER_OBJECTS := $(OTHER_SOURCE:.c=.h)

%.o: %.c %.h
    gcc $(CFLAGS) $(INCLUDE) -c $?

%.o: %.c
    gcc $(CFLAGS) $(INCLUDE) -c $? -o $@


finput: HEADERS+=pliki.h

finput: $(FILE_OBJECTS) $(OTHER_OBJECTS) main.o
    gcc $(CFLAGS) -o $(NAME) $^ -D WEWY_PLIKI 

main.o: main.c $(HEADERS)
    gcc $(CFLAGS) $(INCLUDE) -c src/main.c

clean: 
    rm -rf *.o

The goal is, to make compiled program run a bit differently based on make , hence the -D option and adding

finput: HEADERS+=pliki.h

this finput is the first of the 4 possible options. Each option will be using slightly different set of .c and .h files

Now, when I do

make finput

i get the listing:

gcc  -I src/include -c ./src/we_wy/pliki.c ./src/include/pliki.h
gcc  -I src/include -c ./src/we_wy/wczytaj_plik.c -o wczytaj_plik.o
gcc  -I src/include -c ./src/we_wy/wypisz_plik.c -o wypisz_plik.o
gcc  -I src/include -c src/main.c
gcc  -o macierze pliki.o wczytaj_plik.o wypisz_plik.o ./src/include/suma.h ./src/include/roznica.h ./src/include/iloczyn.h ./src/include/macierz.h main.o -D WEWY_PLIKI 
wczytaj_plik.o: In function `wczytaj':
wczytaj_plik.c:(.text+0x5f): undefined reference to `macierz_alokuj'
main.o: In function `main':
main.c:(.text+0x7e): undefined reference to `suma'
<and other undefined references in main>

I noticed few errors:
1. it doesen’t produce .o files from $(OTHER_OBJECTS)
2. there is no -Wall option from $(CFLAGS)
3. and of course it doesen’t complete.

I would be grateful for some info, what am I doing wrong.

Answer 1

OTHER_OBJECTS := $(OTHER_SOURCE:.c=.h)

If this is not a typo, it is the explanation for (1.). You rename the files to header files, and the header files are found in VPATH and have no remake rules, so they are included verbatim in $^. Try $(OTHER_SOURCE:.c=.o).

CLFAGS = -Wall

Try CFLAGS instead.