I have a beginner's question about a Makefile. I have a very simple makefile containing:
SHELL = /bin/sh
CC = gcc
CFLAGS = -lm -std=c99 -g -o0
EXEC = test
BUILDDIR = build
OBJDIR = obj
SOURCES = $(shell cat sources.list)
DEPS = $(shell cat headers.list)
OBJ = $(SOURCES:.c=.o)
OBJECTS = $(patsubst %,$(OBJDIR)/%,$(OBJ))
all: $(OBJECTS)
$(CC) $(CFLAGS) $(OBJECTS) -o $(BUILDDIR)/$(EXEC)
$(OBJDIR)/%.o: %.c $(DEPS)
$(CC) -c $< -o $#
clean:
rm -f $(BUILDDIR)/$(EXEC) $(OBJDIR)/*.o
My Problem is, if I try to use this Makefile to compile, it returns the error message:
there is no rule for the target obj/Name.o
What am I doing wrong?
After the first few comments and further research I got to this working Version, but it does not create the object files in the obj folder, so it is not what I aim for
SHELL = /bin/sh
CC = gcc
CFLAGS = -lm -std=c99 -g -o0
EXEC = test
BUILDDIR = build
OBJDIR = obj
SOURCES = $(shell cat sources.list)
DEPS = $(shell cat headers.list)
OBJ = $(SOURCES:.c=.o)
OBJECTS = $(patsubst %,$(OBJDIR)/%,$(OBJ))
all: $(BUILDDIR)/$(EXEC)
$(BUILDDIR)/$(EXEC): $(OBJ)
$(CC) $(CFLAGS) $(OBJ) -o $(BUILDDIR)/$(EXEC)
%.o: %.c $(DEPS)
$(CC) -c $< -o $#
clean:
rm -f $(BUILDDIR)/$(EXEC) $(OBJDIR)/*.o
Are all the files in headers.list present at the right place ?
By the way, this is not a good way to handle dependencies on headers. You should take a look at -MP and -MDD and other options of your preprocessor to generate dependencies.
A classical makefile which should do what you need:
SHELL=/bin/bash
CC=gcc
CFLAGS=-std=c99 -g -o0
LDFLAGS=-lm
EXEC=test
BUILDDIR=build/
OBJDIR=obj/
SOURCES=$(shell cat sources.list)
OBJECTS=$(patsubst %.c,$(OBJDIR)%.o,$(notdir $(SOURCES)))
vpath %.c $(sort $(dir $(SOURCES)))
.PHONY:all mrproper clean depends
all:$(BUILDDIR)$(EXEC)
$(BUILDDIR)$(EXEC):$(OBJECTS)|$(BUILDDIR)
$(CC) $(CFLAGS) $^ -o $# $(LDFLAGS)
$(OBJDIR)%.o:%.c|$(OBJDIR)
$(CC) -c $< -o $#
$(BUILDDIR) $(OBJDIR):
mkdir $#
mrproper:clean
rm -f $(BUILDDIR)$(EXEC)
clean:
rm -f $(OBJECTS)
depends:
#rm -f dependencies.mk
#for i in $(SOURCES); do $(CC) -MM $$i -MT $(OBJDIR)`basename $$i | sed s:.c$$:.o:` >> dependencies.mk; done
include $(wildcard dependencies.mk)
If something is not clear, let me know.
Usage:
make depends
make
Related
I'm trying to compile my C project using clang (I'm on MacOS Monterry) and a Makefile, but I keep getting the same error from clang in the command line:
> make
gcc -c src/ji.c src/main.c -o src/ji.o
clang: error: cannot specify -o when generating multiple output files
make: *** [src/ji.o] Error 1
These are the only files I have in the project so far:
src/main.c
src/ji.c
include/ji.h
The Makefile looks like this:
cc = gcc
src = $(wildcard src/*.c)
obj = $(src:.c=.o)
exec = ji
$(exec): $(obj)
$(cc) -Iinclude $< -o build/$#
%.o: %.c
$(cc) -c $(src) -o $#
clean:
-rm src/*.o
-rm ji
From YouTube videos I've seen, this should be the ideal Makefile for the project but no matter what I change I get the error.
There are a few issues:
-Iinclude needs to be on the %.o: %.c rule command
In %.o: %.c, we don't want $(src) but rather $<
We want patsubst to get the .o list obj
The $(exec) target doesn't match the -o option
The clean doesn't match the placement of the executable
Here's a refactored version (e.g. one way to do this--there are others):
cc = gcc
src = $(wildcard src/*.c)
obj = $(patsubst %.c,%.o,$(src))
exec = build/ji
$(exec): $(obj)
mkdir -p build
$(cc) $^ -o $#
%.o: %.c
$(cc) -c $< -o $# -Iinclude
clean:
rm -f src/*.o
rm -fr build
Here's the output of make:
gcc -c src/ji.c -o src/ji.o -Iinclude
gcc -c src/main.c -o src/main.o -Iinclude
mkdir -p build
gcc src/ji.o src/main.o -o build/ji
Here's the output of make clean:
rm -f src/*.o
rm -fr build
This is a part of my makefile :
SRC = ./
DIRS = src libs/maths libs/struct
BIN_DIR = ./bin/
SRC_DIRS= $(foreach dir, $(DIRS), $(addprefix $(SRC), $(dir)))
SRC_TEST= $(sort $(SRC_DIRS))
SRCS = $(foreach msrc, $(SRC_DIRS), $(wildcard $(msrc)/*.c))
DEL_PRE = $(foreach target, $(SRCS), $(notdir $(target)))
ADD_PRE = $(foreach target, $(DEL_PRE), $(addprefix $(BIN_DIR), $(target)))
OBJS = $(ADD_PRE:.c=.o)
.PHONY: all clean re
all: $(EXEC)
$(EXEC): $(OBJS)
$(CC) $(OBJS) -o $# $(LDLIBS)
$(OBJS): $(SRCS)
$(CC) -o $# -c $<
When i use make all, i have in output :
gcc -o bin/main.o -c src/main.c
gcc -o bin/cosin.o -c src/main.c
gcc -o bin/pears.o -c src/main.c
gcc -o bin/outil.o -c src/main.c
gcc -o bin/verif.o -c src/main.c
But i would like to have for each target, it assigned dependency :
gcc -o bin/main.o -c src/main.c
gcc -o bin/cosin.o -c libs/maths/cosin.c
gcc -o bin/pears.o -c libs/maths/pears.c
gcc -o bin/outil.o -c libs/struct/outil.c
gcc -o bin/verif.o -c libs/struct/verif.c
How can i fix it ?
This seems like a very common misconception; I just answered effectively this same question yesterday. I'm not sure where it comes from or how to combat it.
This rule:
$(OBJS): $(SRCS)
$(CC) -o $# -c $<
does not somehow magically combine the contents of the OBJS variable and the SRCS variable to figure out how they match up. The variable references are simply expanded, and the result is this:
bin/main.o bin/cosin.o ... : src/main.c libs/maths/cosin.c ...
$(CC) -o $# -c $<
which is the same as if you'd written this:
bin/main.o : src/main.c libs/maths/cosin.c ...
$(CC) -o $# -c $<
bin/cosin.o : src/main.c libs/maths/cosin.c ...
$(CC) -o $# -c $<
...
Now, you can hopefully see why you compile the same file: in every rule you have the same prerequisites, so $< is always the first one, which is always src/main.c.
There are multiple ways to work this but if you really want to have all the source files from different directories compiled into object files in the same directory your job is harder, because there's no common pattern that will match them all. In this case the simplest thing to do is use VPATH for directory search: replace the above rule with this:
$(BIN_DIR)/%.o : %.c
$(CC) -o $# -c $<
then tell make how to find your source files, like this:
VPATH := $(sort $(dir $(SRCS))
Be aware this method can't be used for any source files that are themselves generated output that make is expected to create.
Teacher gave us this makefile for compiling two C files and storing the objects into a directory called object. It compiles the programs fine however it doesn't store their objects into the directory, and it also doesn't even create the directory. Not sure what to do and could really use some help.
This is my make file
CC = clang
CFLAGS = -g -Wall
OBJDIR = object
HDRS = $(wildcard *.h)
SRCS = $(wildcard *.c)
OBJS = $(addprefix $(OBJDIR)/, $(SRCS:.c=.o))
.PHONY: all
all: client server
# WARNING: must have a tab before each definition
$(OBJDIR)/client.o: client.c $(HDRS) $(OBJDIR)
$(CC) $(CFLAGS) -c client.c -o object/client.o
$(OBJDIR)/server .o: server.c $(HDRS) $(OBJDIR)
$(CC) $(CFLAGS) -c server.c -o object/server.o
$(OBJDIR)/%.o: %.c $(HDRS) $(OBJDIR)
$(CC) $(CFLAGS) -c $*.c -o object/$*.o
$(OBJDIR):
mkdir $(OBJDIR)
.PHONY: clean
clean:
rm -f $(TARGET) $(OBJS)
All I had to do was add multiple targets to the makefile and change all to target the targets
CC = clang
CFLAGS = -g -Wall
# TODO: rename the target to something meaningful!
TARGET = client server
OBJDIR = object
HDRS = $(wildcard *.h)
SRCS = $(wildcard *.c)
OBJS = $(addprefix $(OBJDIR)/, $(SRCS:.c=.o))
.PHONY: all
all: $(TARGET)
# WARNING: *must* have a tab before each definition
$(TARGET): $(OBJDIR) $(OBJS)
$(CC) $(CFLAGS) $(OBJDIR)/protocol.o $(OBJDIR)/$#.o -o $#
$(OBJDIR)/%.o: %.c $(HDRS) $(OBJDIR)
$(CC) $(CFLAGS) -c $*.c -o object/$*.o
$(OBJDIR):
mkdir $(OBJDIR)
.PHONY: clean
clean:
rm -f $(TARGET) $(OBJS)
So, I can understand what the problem is here, but I can't quite figure out how to fix it -- Because it is compiling files from a different directory, but throwing the .a library file and executable into the root...It seems that the makefile is expecting them to be in their source directory, and that's why it rebuilds every time even when no changes are made.
Problem is, my school is very strict on folder structure, so it needs to compile exactly how it is, I just need to figure out how to let the makefile know the executable and library file DO exist, in the root directory.
Here is my Makefile:
NAME = fillit
LIB = libft.a
CC = gcc
CFLAGS = -Wall -Wextra -Werror
RM = /bin/rm -rf
SRC = main.c validation.c create_piece.c game_board.c solver.c tables.c \
trimmer.c
LIBSRC = ft_putchar.c ft_putstr.c ft_strcpy.c ft_strnew.c ft_strdel.c \
ft_strequ.c ft_putendl.c ft_error.c
LIBLIST := $(shell ls -1 libft | grep .c$$)
LIBOBJ := $(LIBLIST:.c=.o)
LIBOBJ := $(addprefix libft/, $(LIBOBJ))
SRCLIST := $(shell ls -1 src | grep .c$$)
SRCOBJ := $(SRCLIST:.c=.o)
SRCOBJ := $(addprefix src/, $(SRCOBJ))
.PHONY: all $(NAME) lib
all: $(NAME)
libft/%.o: libft/%.c
$(CC) $(CFLAGS) -c -o $# $<
src/%.o: src/%.c
$(CC) $(CFLAGS) -c -o $# $<
lib:
ar rc $(LIB) $(LIBOBJ)
ranlib $(LIB)
debug:
$(CC) $(CFLAGS) $(addprefix libft/, $(LIBLIST)) $(addprefix src/, $(SRCLIST)) -g -o fillit
$(NAME): $(LIBOBJ) $(SRCOBJ) lib
$(CC) $(CFLAGS) $(SRCOBJ) -L. -lft -o fillit
clean:
$(RM) $(SRCOBJ)
$(RM) $(LIBOBJ)
fclean: clean
$(RM) $(NAME)
$(RM) $(LIB)
re: fclean all
re-db: fclean debug
It's working fine for compiling the .o files, it only does that once, but if I continue to type make, it still compiles this part:
➜ fillit git:(master) ✗ make
ar rc libft.a libft/ft_memset.o libft/ft_putchar.o libft/ft_putendl.o libft/ft_putstr.o libft/ft_strcpy.o libft/ft_strdel.o libft/ft_strequ.o libft/ft_strnew.o
ranlib libft.a
gcc -Wall -Wextra -Werror src/create_piece.o src/game_board.o src/main.o src/solver.o src/tables.o src/trimmer.o src/validation.o -L. -lft -o fillit
Want to thank kaylum for pointing me in the right direction, I have figured out how to solve this problem. I changed lib to $(LIB) and removed $(NAME) and lib from the phony list. Working makefile:
NAME = fillit
LIB = libft.a
CC = gcc
CFLAGS = -Wall -Wextra -Werror
RM = /bin/rm -rf
SRC = main.c validation.c create_piece.c game_board.c solver.c tables.c \
trimmer.c
LIBSRC = ft_putchar.c ft_putstr.c ft_strcpy.c ft_strnew.c ft_strdel.c \
ft_strequ.c ft_putendl.c ft_error.c
LIBLIST := $(shell ls -1 libft | grep .c$$)
LIBOBJ := $(LIBLIST:.c=.o)
LIBOBJ := $(addprefix libft/, $(LIBOBJ))
SRCLIST := $(shell ls -1 src | grep .c$$)
SRCOBJ := $(SRCLIST:.c=.o)
SRCOBJ := $(addprefix src/, $(SRCOBJ))
.PHONY: all
all: $(NAME)
libft/%.o: libft/%.c
$(CC) $(CFLAGS) -c -o $# $<
src/%.o: src/%.c
$(CC) $(CFLAGS) -c -o $# $<
$(LIB):
ar rc $(LIB) $(LIBOBJ)
ranlib $(LIB)
debug:
$(CC) $(CFLAGS) $(addprefix libft/, $(LIBLIST)) $(addprefix src/, $(SRCLIST)) -g -o fillit
$(NAME): $(LIBOBJ) $(SRCOBJ) $(LIB)
$(CC) $(CFLAGS) $(SRCOBJ) -L. -lft -o $(NAME)
clean:
$(RM) $(SRCOBJ)
$(RM) $(LIBOBJ)
fclean: clean
$(RM) $(NAME)
$(RM) $(LIB)
re: fclean all
re-db: fclean debug
I am trying to get this makefile relink and not recompile unessecarily files that aren't modified. The "libft" is my library and doesnt have any errors. The error that I am having when doing
make
is :
make: *** No rule to make target `main.o', needed by `ft_printf'. Stop.
My makefile is:
NAME = ft_printf
SRC = main.c\
ft_printf.c\
parser_main.c\
utils.c\
debug_funcs.c
OBJ = $(SRC:.c=.o)
SRC_PATH = srcs/
SRC_POS = $(addprefix $(SRC_PATH),$(SRC))
INC = -I includes
LIBFT = libft/libft.a
CC = gcc
FLAGS = -Wall -Wextra -Werror
all: $(NAME)
$(NAME): $(OBJ)
$(CC) $(FLAGS) $(OBJ) -o $(NAME) $(LIBFT)
%.o: %.c
$(CC) -o $# -c $< $(FLAGS)
$(LIBFT):
make -C ./libft/
clean:
rm -f $(OBJ)
make clean -C ./libft/
fclean: clean
rm -f $(NAME)
make fclean -C ./libft/
re: fclean all
Any idea ? I can't figure it out and i think it's because %.o:%.c isn't called
Given the existence of these variables:
SRC_PATH = srcs/
SRC_POS = $(addprefix $(SRC_PATH),$(SRC))
I'm guessing that your source files actually live in srcs/ whereas you're building your object files in . So this pattern rule:
%.o: %.c
when trying to match main.o won't find a main.c since that file really is srcs/main.c. Since that pattern doesn't match, the rule itself isn't considered, and since no other rule is found, you get an error.
Instead, try:
%.o : $(SRC_PATH)/%.c
$(CC) -o $# -c $< $(FLAGS)