makefile to create own directory for object files not working

Question

I am new to makefiles and want to save all my object files in an own directory. I googled a lot and came to that solution:

CXX = clang++

# compiler flags
CXXFLAGS = -O3 -Wall -Werror -std=c++11
CFLAGS_SFML = -lsfml-graphics -lsfml-window -lsfml-system
SRCS = getInput.cpp createOutput.cpp main.cpp
OBJDIR = obj
OBJS = $(addprefix $(OBJDIR)/, SRCS:.cpp=.o)

all: program.exe

program.exe: $(OBJS)
    $(CXX) $(CXXFLAGS) -o program.exe $(OBJS) $(CFLAGS_SFML)

$(OBJDIR)/%.o: %.cpp
    $(CXX) $(CXXFLAGS) -c $< -o $@

When I try to run the makefile I get this error:

makefile:12: *** target pattern contains no `%'. Stop.

It seems as this error is quite common and does not tell the detail about what is wrong. It would be great if someone could help me.

Are your sources .c files or .cpp? You mention one in une place and the other a few lines below — marom, Jan 05 '16 at 11:11
Sorry, that was just a typo while writing the question. It's cpp — Natjo, Jan 05 '16 at 11:18
@Jonas $(XX) and $(CC) are also not defined with in this Makefile. — sanjay, Jan 05 '16 at 11:34
Try `$(OBJS): $(OBJDIR)/%.o: $(SRCS)/%.cpp` instead of `$(OBJDIR)/%.o: %.cpp`. — user657267, Jan 05 '16 at 12:14

score 1 · Accepted Answer · edited May 23 '17 at 12:04

1

Problem with OBJS = $(addprefix $(OBJDIR)/, SRCS:.cpp=.o)

Try this one. First you have to make the obj directory also.

CXX = clang++

# compiler flags
CXXFLAGS = -O3 -Wall -Werror -std=c++11
CFLAGS_SFML = -lsfml-graphics -lsfml-window -lsfml-system
SRCS = main.cpp
OBJDIR = obj
OBJS = $(addprefix $(OBJDIR)/, $(SRCS:.cpp=.o))


all: program.exe

program.exe: $(OBJS)
    $(CXX) $(CXXFLAGS) -o program.exe $(OBJS) $(CFLAGS_SFML)

$(OBJDIR)/%.o: %.cpp
    $(CXX) $(CXXFLAGS) -c $< -o $@

For more information use this.

edited May 23 '17 at 12:04

Community

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answered Jan 05 '16 at 12:39

sanjay

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Thank you, that solved my problem. great. Just one last thing, it complains the directory "obj" does not exist. So when I add it manually everything works fine. But is there a more elegant solution? – Natjo Jan 05 '16 at 12:46
@Jonas i am not expert in makefile. You can refer to this book http://www.oreilly.com/openbook/make3/book/index.csp. Mark as solution and upvote :P – sanjay Jan 05 '16 at 12:48
I will suggest you to use some IDE or buil tool like CMake. Because it's better to spend time on code rather build system – sanjay Jan 05 '16 at 13:00

makefile to create own directory for object files not working

1 Answers1