又学了一天Makefile，不过这次感觉比以前简单多了，看起来也不是那么的繁琐了，学会了利用GCC自动处理依赖关系，一点进步。下面这个是一个比较通用的Makefile，主要就是修改了一下对依赖关系的处理（带中文注释的地方），对于小工程来说还是很实用的。呵呵～
# The executable file name. # It must be specified. # PROGRAM := a.out # the executable name PROGRAM := #source directories APPSRC := # The directories in which source files reside. # At least one path should be specified. # SRCDIRS := . # current directory SRCDIRS :=. $(APPSRC) # The source file types (headers excluded). # At least one type should be specified. # The valid suffixes are among of .c, .C, .cc, .cpp, .CPP, .c++, .cp, or .cxx. # SRCEXTS := .c # C program # SRCEXTS := .cpp # C++ program # SRCEXTS := .c .cpp # C/C++ program SRCEXTS :=.c # The flags used by the cpp (man cpp for more). # CPPFLAGS := -Wall -Werror # show all warnings and take them as errors CPPFLAGS := # The compiling flags used only for C. # If it is a C++ program, no need to set these flags. # If it is a C and C++ merging program, set these flags for the C parts. CFLAGS := CFLAGS += # The compiling flags used only for C++. # If it is a C program, no need to set these flags. # If it is a C and C++ merging program, set these flags for the C++ parts. CXXFLAGS := CXXFLAGS += # The library and the link options ( C and C++ common). LDFLAGS := LDFLAGS += ## Implict Section: change the following only when necessary. ##============================================================================= # The C program compiler. Uncomment it to specify yours explicitly. CC = gcc # The C++ program compiler. Uncomment it to specify yours explicitly. CXX = g++ # Uncomment the 2 lines to compile C programs as C++ ones. #CC = $(CXX) #CFLAGS = $(CXXFLAGS) # The command used to delete file. RM = rm -f ## Stable Section: usually no need to be changed. But you can add more. ##============================================================================= SHELL = /bin/sh SOURCES = $(foreach d,$(SRCDIRS),$(wildcard $(addprefix $(d)/*,$(SRCEXTS)))) OBJS = $(foreach x,$(SRCEXTS), / $(patsubst %$(x),%.o,$(filter %$(x),$(SOURCES)))) DEPS = $(patsubst %.o,%.d,$(OBJS)) .PHONY : all objs clean cleanall rebuild all : $(PROGRAM) # Rules for creating the dependency files (.d). # 使用GCC生成依赖关系，这里需要做些处理，共有三步: # A：$(CC) -MM $(CFLAGS) $< > $@.$$$$ 为每个xxx.c文件生成依赖文件 xxx.d.$$$$，‘$’为随机数字 # B：GCC生成的依赖关系中会去掉.o文件的文件目录，类似于： xxx.o: src/xxx.c include/xxx.h # 使用sed工具将其替换为 src/xxx.o src/xxx.d: src/xxx.c include/xxx.h，让xxx.d也一样依赖 # 于源文件，这样当.c源文件或着头文件有任何更新时，相应的.d文件也会被更新。注意这里sed的用 # 法和命令行的不太一样，分隔符必须是','而不是'/'，并且-i参数也不能用了，所以只能使用重定向 # sed 's,.*/.o[: ]*/(.*/)/.c,/1.o $@:/ /1.c/ ,g' < $@.$$$$ > $@ # C：rm -f $@.$$$$ 这个简单，把作为临时文件的 xxx.d.$$$$ 删除 # 注意： # 这三条命令是用连行符连起来的，否则 $@.$$$$ 文件可能就没法使用了，还有每行最后的';'也不能少 #--------------------------------------------------- %.d : %.c @$(CC) -MM $(CFLAGS) $< > $@.$$$$; / sed 's,.*/.o[: ]*/(.*/)/.c,/1.o $@:/ /1.c/ ,g' < $@.$$$$ > $@; / $(RM) $@.$$$$ # Rules for producing the objects. #--------------------------------------------------- objs : $(OBJS) %.o : %.c $(CC) -c $(CPPFLAGS) $(CFLAGS) $< -o $@ # Rules for producing the executable. #---------------------------------------------- $(PROGRAM) : $(OBJS) $(CXX) -o $(PROGRAM) $(OBJS) $(LDFLAGS) #将依赖关系包含到Makefile中来 -include $(DEPS) rebuild: clean all clean : @$(RM) $(OBJS) $(DEPS) cleanall: clean @$(RM) $(PROGRAM) ### End of the Makefile ## Suggestions are welcome ## All rights reserved ### ###############################################################################
