Makefile on different folders - c++

Question

I know it has already been discussed a lot, but I'm getting a bit crazy and cannot figured it out by myself.
I'm trying to learn how to create makefiles, and I'm having problems in defining a makefile for files in different folders.
This is what I would like to obtain, after compiling:
/makefile
/test.exe
/src/factorials.cpp
/src/main.cpp
/src/hello.cpp
/obj/factorials.o
/obj/main.o
/obj/hello.o
/include/functions.h
What is wrong with this makefile?
C++ = g++
FILENAME = test
SOURCES_PATH = src/
SRC = $(SOURCES_PATH)factorial.cpp $(SOURCES_PATH)main.cpp $(SOURCES_PATH)hello.cpp
OBJ = factorial.o main.o hello.o
all: test.exe
test.exe: $(OBJ)
$(C++) $(OBJ) -o $(FILENAME) -Iinclude
%.o:
$(C++) -c $(SOURCES_PATH)$*.cpp -Iinclude
clean:
rm -f test.exe
Everything goes correctly, but it gives me error trying to compile src/all.cpp. Besides, I don't know how to say to g++ to put .o files into obj/ folder.
Thanks a lot!

Answer 1

You should fix your .o rule as follows
obj/%.o: $(SOURCES_PATH)/%.cpp
$(CC) $(CXXFLAGS) $< -o $#
Alternatively $(vpath) can be used to resolve where make looks up the source (prerequisite) files for a target:
vpath += $(SOURCES_PATH)
obj/%.o: %.cpp
$(CC) $(CXXFLAGS) $< -o $#

Answer 2

So it seems I was able to obtain the result by using the following makefile
C++ = g++
FILENAME = test
OBJS = obj/factorial.o obj/hello.o obj/main.o
INC = -Iinclude/
vpath+= src
$(FILENAME): $(OBJS)
$(C++) $(OBJS) -o $# $(INC)
obj/%.o: %.cpp
$(C++) -o $# -c $< $(INC)
all: $(FILENAME)
clean:
rm -rf objs/*.o *~ $(FILENAME).exe
Thanks! :)