Makefile tổng quát

Hôm qua lọ mọ viết một Makefile cho sinh viên cho các bài tập lập trình học kỳ tới. Makefile này khá tổng quát cho các chương trình cỡ chục nghìn dòng lệnh đổ lại. Nó giả sử là mỗi .c đều có .h tương ứng. Dễ dàng sửa lại một chút để nó dịch các chương trình C++. Ghi lại đây biết đâu lại có lợi cho ai đó.

#############################################################################
#   $ make           compile and link all C programs specified with PROGS
#   $ make clean     clean objects and the executable file
#   $ make distclean clean objects, the executable and dependencies
# I assume that each .c has a .h of the same name in directory INC_DIR
# You can compile multiple programs by redefining $(PROGS)
#===========================================================================

## Customizable Section: adapt those variables to suit your program.
##==========================================================================
# The pre-processor and compiler options.
MY_CFLAGS = -I./include -DBE_DEBUG -D_REENTRANT -Wall -D__EXTENSIONS__

# Libraries to link to, depending on OS
UNAME = $(shell uname)
ifeq ($(UNAME), SunOS)              # Sun OS
MY_LIBS = -lresolv -lsocket -lnsl
endif
ifeq ($(UNAME), Linux)              # Linux
MY_LIBS = -lresolv -lnsl
endif
ifeq ($(UNAME), Darwin)             # Mac OS
MY_LIBS =
endif

# Directory where your .h files are
INC_DIR := ./include

# The options used in linking as well as in any direct use of ld.
LDFLAGS +=

# The executable file names.
PROGS   = server client iom_client

## Implicit Section: change the following only when necessary.
##==========================================================================

CC := gcc
SRCS := $(wildcard *.c)

# objects other than those in PROGS
ALL_OBJS := ${SRCS:.c=.o}
ALL_NAMES := ${ALL_OBJS:.o=}

# all object files other than those named $(PROGS).o
COMMON_OBJS :=
define APPEND_CO
ifeq (,$(findstring $(1), $(PROGS)))
COMMON_OBJS += $(1).o
endif
endef
$(foreach name,$(ALL_NAMES),$(eval $(call APPEND_CO, $(name))))

.PHONY: all clean distclean

all: $(PROGS)

define PROG_RULE
$(1) : $(COMMON_OBJS) $(1).o
        ${CC} -I${INC_DIR} ${CFLAGS} ${MY_LIBS} ${COMMON_OBJS} $(1).c -o $(1)
endef

$(foreach program,$(PROGS),$(eval $(call PROG_RULE, $(program))))

## Objects are dependent on headers (and implicitly .c files)
##==========================================================================
define OBJ_RULE
$(1) : ${INC_DIR}/${1:.o=.h} ${1:.o=.c}
        ${CC} -I${INC_DIR} ${CFLAGS} -c ${1:.o=.c}
endef

$(foreach obj_file,$(ALL_OBJS),$(eval $(call OBJ_RULE,$(obj_file))))

## clean things up
##==========================================================================
clean:
        @- $(RM) $(PROGS)
        @- $(RM) $(ALL_OBJS)

distclean: clean