# An "omnipotent" makefile for g++ that builds the
# dependecy tree "automagically".
# I assume that you have a subfolder ./src that contains
# all your .cpp and .hpp files, and that you made a subfolder
# ./obj that will contain the .o files.
# Hint: the compiler option -MMD does a lot of magic.
# -----------------------------------------------------------
# the compiler, in my case the C++ compiler
CC = g++
# flags for compiling .cpp files
CC_FLAGS = -O3 -Wall -c
# flags for linking the .o files
LD_FLAGS = -O3 -Wall
# all my .cpp files are saved in a folder ./src
CPP_FILES := $(wildcard src/*.cpp)
# and I want my .o files to be stored in a ./obj folder
OBJ_FILES := $(addprefix obj/,$(notdir $(CPP_FILES:.cpp=.o)))
 
# the target "all" is my main executable called
# "hawaiitoaster" (make, make all)
all: hawaiitoaster

# a rule for cleaning up (make clean)
clean:
	rm -f obj/*.o obj/*.d hawaiitoaster
 
# the rule for the main executable
hawaiitoaster: $(OBJ_FILES)
	$(CC) $(LD_FLAGS) $^ -o $@
 
# a pattern for compiling .cpp files
# (and hence, making the .o files)
obj/%.o: src/%.cpp $^
	$(CC) $(CC_FLAGS) $< -o $@
 
# now include dependencies. "gcc -c -MMD src/foo.cpp -o obj/foo.o"
# will make a file foo.d (and foo.o). The foo.d file contains the
# line "obj/foo.o: src/foo.cpp src/foo.hpp src/bar.hpp", depending
# on whatever has been "#include"d in the header "foo.hpp".
CC_FLAGS += -MMD
-include $(OBJ_FILES:.o=.d)