CODEWITHSUNDEEP
cmakefile
zidanow
zidanow

Reputation: 700

makefile rebuild even is it up to date

My makefile always rebuild, don't understand why..

Here it is : 

SRC =   $(DIR)/my_getnbr.c \
        $(DIR)/my_isneg.c \
        $(DIR)/my_putchar.c \

OBJ =   $(SRC:.c=.o)

DIR =   lib/my

LIB_DIR =   lib

NAME    =   libmy.a

MYH =   include/my.h

BUILD = ar rcs $(NAME) $(DIR)/*.o

MV =    mv $(NAME) $(LIB_DIR)

CP =    cp $(MYH) $(DIR)

all:    $(NAME)

$(NAME):    $(OBJ)
            $(BUILD)
            $(MV)
            $(CP)

clean:
    rm -f $(OBJ)

fclean:clean
    rm -f $(LIB_DIR)/$(NAME)

re: fclean all

.PHONY: fclean all re clean

I added the .PHONY but it changes anything :(

He always do the BUILD, MV and CP calls. If i delete them from the Makefile, it will not rebuild if he is up to date (only with the .OBJ). Thanks again.

Upvotes: 2

Views: 397

Answers (1)

Lesmana
Lesmana

Reputation: 27053

you are moving libmy.a to the directory lib. the next time you run make it will look for libmy.a and since it doesn't exists it will be build.

make will always look for the targets (libmy.a in your case) in the current directory. so if you are moving the file to another place make will think the file has not been created.

rule of thumb is: the recipe for a target should always create the file named by the target.

possible solutions:

  • not move the file
  • qualify the target name with the directory (NAME = lib/libmy.a) (perhaps easiest in your case)
  • create a dummy file in place of the moved file for make to see the file exists. but this is complicated and prone to missunderstandings if not done well.

Upvotes: 5

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