Why is Makefile not including the header? - makefile

Question

I'm trying to make a library for my project but I am very very new to Makefiles. I tried several configurations and adding -I but none worked.
I have the following three:
libft/
../includes/
....libft.h
../lst
....ft_lstnew.c
....ft_lstadd_front.c
....ft_lstadd_back.c
.... [...]
../src
....ft_isalpha.c
....ft_isalnum.c
.... [...]
And the following makefile:
NAME=libft.a
LIBSO=libft.so
CC=gcc
CFLAGS=-Wall -Wextra -Werror
SRC_DIR=src/
BONUS_DIR=lst/
OBJ_DIR=obj/
SRC_FILES= ft_bzero.c \
ft_isalmun.c \
ft_isalpha.c \
ft_isascii.c \
ft_isdigit.c \
ft_isprint.c \
ft_memchr.c \
ft_memcpy.c \
ft_memmove.c \
ft_memset.c \
ft_strchr.c \
ft_strlcat.c \
ft_strlcpy.c \
ft_strlen.c \
ft_strncmp.c \
ft_strrchr.c \
ft_tolower.c \
ft_toupper.c
BONUS_FILES=ft_lstadd_back.c \
ft_lstadd_front.c \
ft_lstdelone.c \
ft_lstclear.c \
ft_lstiter.c \
ft_lstlast.c \
ft_lstmap.c \
ft_lstnew.c \
ft_lstsize.c
SRC_PATH=$(addprefix $(SRC_DIR), $(SRC_FILES))
BONUS_PATH=$(addprefix $(BONUS_DIR), $(BONUS_FILES))
SRC_NAMES=$(SRC_FILES:.c=.o)
BONUS_NAMES=$(BONUS_FILES:.c=.o)
SRC_PATH_O=$(addprefix $(SRC_DIR), $(SRC_NAMES))
BONUS_PATH_O=$(addprefix $(BONUS_DIR), $(BONUS_NAMES))
HDR_NAME=libft.h
HDR_DIR=includes/
HDR= $(addprefix $(HDR_DIR),$(HDR_NAME))
all: $(NAME)
$(NAME): $(SRC_PATH_O)
ar rc $# $<
ranlib $#
$(OBJ_DIR):
mkdir $#
$(OBJ_DIR)%.o: $(SRC_DIR)%.c $(HDR_NAME)
$(CC) $(CFLAGS) -c $< -o $# -I $(HDR)
clean:
rm -rf $(OBJ_DIR)
fclean: clean
rm -f $(NAME)
re: fclean all
.PHONY: all clean fclean re
And I keep getting this each time I type make on the terminal:
gcc -Wall -Wextra -Werror -c -o src/ft_bzero.o src/ft_bzero.c
src/ft_bzero.c:1:10: fatal error: libft.h: No such file or directory
1 | #include "libft.h"
| ^~~~~~~~~
compilation terminated.
make: *** [<builtin>: src/ft_bzero.o] Error 1
Am I missing something? It's literally my first time.

Answer 1

Yes, you're missing some things.
First, look at the command line make shows:
gcc -Wall -Wextra -Werror -c -o src/ft_bzero.o src/ft_bzero.c
Note that the output here is not right for the recipe of the pattern rule you created: there's no -I option, and the object file is being written to src/ not obj/.
From this you should realize that your pattern rule is not being used at all, and instead make is using its built-in rule for building object files.
Why isn't your pattern rule being used? Let's look at it:
$(OBJ_DIR)%.o: $(SRC_DIR)%.c $(HDR_NAME)
what is this after variable expansion?
obj/%.o: src/%.c libft.h
This pattern (like all patterns) can only match if ALL the prerequisites either already exist or can be built. The src/%.c exists, after the pattern substitution. What about libft.h? No, that doesn't exist. What does exist is includes/libft.h but that's not the same thing.
So, this rule fails to match and make goes back to using its default rules.
If you want to say that every object file depends on that header, you have to use the correct path to the header file when you write the pattern.
Next, this is wrong:
$(CC) $(CFLAGS) -c $< -o $# -I $(HDR)
What is $(HDR)? It's the name of the file: include/libft.h. You don't include header file names with -I; you include directories that headers are looked for in. So you need $(HDR_DIR) here instead.