Makefile exits with fatal error - c++

Question

I have a project with following structure:
$ tree
.
├── bin
├── include
│   └── reader.h
├── Makefile
├── obj
└── src
├── main.cpp
└── reader.cpp
4 directories, 4 files
I want to have .cpp file in src/, headers in include/ , compile object files in obj/ and executables in bin/. I use GNU make in version 4.1, g++ in version 7.2.0 and Ubuntu 17.10. When I try to build it (I try to use ideas from here, slightly modified) I get following error:
$ make
make: Circular obj/main.o <- obj/main.o dependency dropped.
make: Circular obj/reader.o <- obj/main.o dependency dropped.
make: Circular obj/reader.o <- obj/reader.o dependency dropped.
g++ -c -o obj/obj/reader.o include/reader.h
In file included from <command-line>:0:0:
/usr/include/stdc-predef.h:1:0: fatal error: can’t create precompiled header obj/obj/reader.o: No such file or directory
/* Copyright (C) 1991-2017 Free Software Foundation, Inc.
compilation terminated.
Makefile:15: recipe for target 'obj/reader.o' failed
make: *** [obj/reader.o] Error 1
I am new to makefiles, so I guess it's something very basic. How can I fix this?
EDIT I forgot about Makefile`. Here we go:
IDIR = include
OBJDIR = obj
CXX = g++
CXXFLAGS = -g -Wall -std=c++14 -I$(IDIR)
DEPS = reader.h
_DEPS = reader.h
DEPS = $(patsubst %,$(IDIR)/%,$(_DEPS))
_OBJ = main.o reader.o
OBJ = $(patsubst %,$(OBJDIR)/%,$(_OBJ))
$(OBJDIR)/%.o: $(OBJ) $(DEPS)
$(CXX) -c -o $(OBJDIR)/$# $< $(CFLAGS)
main: $(OBJ)
$(CXX) -o $# $^ $(CXXFLAGS)
EDIT2 After changing language to English I understood the warnings I had.
I deleted redundant $(OBJDIR) part from $(OBJDIR)/%.o directive and ended up with something like this:
IDIR = include
OBJDIR = obj
CXX = g++
CXXFLAGS = -g -Wall -std=c++14 -I$(IDIR)
DEPS = reader.h
_DEPS = reader.h
DEPS = $(patsubst %,$(IDIR)/%,$(_DEPS))
_OBJ = main.o reader.o
OBJ = $(patsubst %,$(OBJDIR)/%,$(_OBJ))
$(OBJDIR)/%.o: $(OBJ) $(DEPS)
$(CXX) -c -o $# $< $(CFLAGS)
main: $(OBJ)
$(CXX) -o $# $^ $(CXXFLAGS)
and new errors:
$ make
make: Circular obj/main.o <- obj/main.o dependency dropped.
make: Circular obj/reader.o <- obj/main.o dependency dropped.
make: Circular obj/reader.o <- obj/reader.o dependency dropped.
g++ -c -o obj/main.o obj/reader.o
g++: warning: obj/reader.o: linker input file unused because linking not done
g++ -o main obj/main.o obj/reader.o -g -Wall -std=c++14 -Iinclude
g++: error: obj/main.o: No such file or directory
Makefile:18: recipe for target 'main' failed
make: *** [main] Error 1

Answer 1

$(OBJDIR)/%.o: $(OBJ) $(DEPS) makes no sense. You're saying every object file depends on itself (and also all other object files). That's why make is complaining Circular obj/main.o <- obj/main.o dependency dropped.. $(OBJ) shouldn't be there.
$(CXX) -c -o $# $< $(CFLAGS) is broken because $< is the first prerequisite, which in this case is obj/reader.o. It's like you're trying to compile one object file into another, which makes no sense.
Also, why are you using $(CFLAGS) here? You're compiling C++, so it should be $(CXXFLAGS) (your code never sets CFLAGS anyway).
Your Makefile never mentions any cpp files. This cannot work.
I would throw away your Makefile and start with something simple:
CXXFLAGS = -g -Wall -std=c++14 -Iinclude
bin/main: obj/main.o obj/reader.o
$(CXX) -o $# $(LDFLAGS) $+ $(LDLIBS)
obj/main.o: src/main.cpp include/reader.h
obj/reader.o: src/reader.cpp include/reader.h
This should be all you need.