Makefile_3_outofsrc

# Makefile

# 1. Generating prerequisites automatically for header files
# 2. Compile source files automatically in current directory tree
# 3. Out of source tree build

# .
# ├── f1.c
# ├── f1.h
# ├── f2
# │   ├── f22
# │   │   ├── f22.c
# │   │   └── f22.h
# │   ├── f2.c
# │   └── f2.h
# ├── main.c
# ├── Makefile
# └── print_log.h

# build shared library with -fPIC, -shared
CFLAGS   = -g # -O3 # -fPIC  # CXXFLAGS for .cpp
LDFLAGS  = # -L../bar -Wl,-rpath,/foo/bar # -shared
LDLIBS   = # -lbar
CPPFLAGS = -MMD -MP # -I../bar
DIR      = ./.build
SRC      = $(shell find . -type f -name "*.c")  # .cpp

$(DIR)/main : $(addprefix $(DIR)/,$(SRC:.c=.o))  # .cpp
	$(CC) $(LDFLAGS) $^ $(LDLIBS) -o $@  # CXX for .cpp

$(DIR)/%.o : %.c  # .cpp
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) $(CPPFLAGS) -c -o $@ $<  # CXX CXXFLAGS for .cpp

-include $(shell find . -type f -name "*.d")
clean : ; -rm -fr $(DIR)
.PHONY : clean