How to move .o on project folder? - makefile

Question

I wrote this Makefile to move all .o of the project inside a directory 'obj' in the main folder.
Directories
.:
actor/ lib/ Controller.cpp Controller.h Controller.o doc.txt main.cpp main.o Makefile uno VRP*
./actor:
Customer.cpp Customer.h Customer.o Depot.cpp Depot.h Depot.o Route.cpp Route.h Route.o Vehicle.cpp Vehicle.h Vehicle.o
./lib:
Search.cpp Search.h Search.o Utils.cpp Utils.h Utils.o VRP.cpp VRP.h VRP.o
Makefile
CXX=g++
RM=rm -rf
BIN_NAME=VRP
CPPFLAGS=-s -O2 -std=gnu++11 -Wall
SRCS=$(wildcard *.cpp actor/*.cpp lib/*.cpp)
OBJS=$(subst .cpp,.o,$(SRCS))
all: $(OBJS_DIR) $(BIN_NAME)
$(OBJS_DIR):
mkdir $(OBJS_DIR)
$OBJS_DIR)/%.o : $(SRCS)
$(CXX) $(CPPFLAGS) -c $< -o $#
$(BIN_NAME) : $(OBJS)
$(CXX) -o $# $^
debug:
$(CXX) -g $(CPPFLAGS) -o $(BIN_NAME) $(OBJS)
.PHONY : all clean
clean:
$(RM) $(OBJS) $(OBJS_DIR)
dist-clean: clean
$(RM) $(BIN_NAME)
How can I make it works?

Answer 1

This line $OBJS_DIR)/%.o : $(SRCS) sets the prerequisites of every file that matches $OBJS_DIR)/%.o to all the files in $(SRCS) that's not even close to what you want. (It is also a typo. You are missing the opening ().
You can't write a single rule for what you are trying to do here you need three pattern rules (or one with a vpath/VPATH setup).
$(OBJS_DIR)/%.o: %.cpp
$(CXX) $(CPPFLAGS) -c $< -o $#
$(OBJS_DIR)/%.o: actor/%.cpp
$(CXX) $(CPPFLAGS) -c $< -o $#
$(OBJS_DIR)/%.o: lib/%.cpp
$(CXX) $(CPPFLAGS) -c $< -o $#
That being said you don't actually have any targets that match $(OBJS_DIR)/%.o since the value of $(OBJS) is Controller.o ... actor/Customer.o ... lib/Search.o. To fix that you also need:
OBJS=$(addprefix $(OBJS_DIR)/,$(patsubst %.cpp,%.o,$(notdir $(SRCS))))
$(notdir) to get just the filename from the source files.
$(patsubst) instead of $(subst) just for correctness (subst would have modified a Bar.cpp.cpp file to Bar.o.o).
$(addprefix) to add the $(OBJS_DIR) prefix to the bare object file names.