Makefile檔案的編寫

################################################################  
#自動將src目錄下所有的cpp、cc和c檔案編譯，生成所有.o檔案儲存在bin/obj下  
#自動生成靜態庫和動態庫檔案到lib目錄下  
#Created by hhsun 2018-06-2                
#################################################################   
PROJECT_TOP_DIR := $(shell pwd)
PROJECT_SRC_DIR := $(PROJECT_TOP_DIR)/src
PROJECT_INC_DIR := $(PROJECT_TOP_DIR)/inc
PROJECT_LIB_DIR := $(PROJECT_TOP_DIR)/lib
PROJECT_OBJ_DIR := $(PROJECT_TOP_DIR)/obj

COMPILER_DIR :=  /home/sunhh/work/txd-25/toolchain/CodeSourcery/Sourcery_CodeBench_Lite_for_Xilinx_GNU_Linux/bin/arm-xilinx-linux-gnueabi-

DATE := $(shell date '+%y-%m-%d-%H')  
CXX := $(COMPILER_DIR)g++  
STRIP := $(COMPILER_DIR)strip 

LIB_NAME := libatsha
AR := $(COMPILER_DIR)ar
SHARED_LIB := $(LIB_NAME).so
STATIC_LIB := $(LIB_NAME).a
TARGETS := $(SHARED_LIB) $(STATIC_LIB)

CXXFLAGS := -g -Wall -Werror -I$(PROJECT_INC_DIR)
LDFLAG := -L$(PROJECT_LIB_DIR)
ARFLAG := rcs
SOFLAG := -shared -fPIC
 
SRCS :=$(wildcard $(PROJECT_SRC_DIR)/*.cpp $(PROJECT_SRC_DIR)/*.cc $(PROJECT_SRC_DIR)/*.c)
SRCS_NODIR := $(notdir $(SRCS))
PROJECT_OBJ_CPP := $(patsubst %.cpp,%.o,$(SRCS_NODIR))
PROJECT_OBJ_CC := $(patsubst %.cc,%.o,$(PROJECT_OBJ_CPP))
PROJECT_OBJ_C := $(patsubst %.c,%.o,$(PROJECT_OBJ_CC))
PROJECT_ALL_OBJS := $(addprefix $(PROJECT_OBJ_DIR)/, $(PROJECT_OBJ_C))

all:$(TARGETS)
	@echo "-----------------------------------------------------------------------------"
	@echo "Build Completed for $(PROJECT_LIB_DIR)/$(TARGETS): $(TARGETS) build"
	@echo "-----------------------------------------------------------------------------"
$(STATIC_LIB): $(PROJECT_ALL_OBJS)
	$(AR) $(ARFLAG) $(PROJECT_LIB_DIR)/
 
[email protected] $^
$(SHARED_LIB): $(PROJECT_ALL_OBJS)
	$(CXX) $(SOFLAG) -o $(PROJECT_LIB_DIR)/[email protected] $^
  
$(PROJECT_OBJ_DIR)/%.o: $(PROJECT_SRC_DIR)/%.cc
	$(CXX) -c $(CXXFLAGS) -o [email protected] $<
$(PROJECT_OBJ_DIR)/%.o: $(PROJECT_SRC_DIR)/%.cpp
	$(CXX) -c $(CXXFLAGS) -o 
 
[email protected] $<
$(PROJECT_OBJ_DIR)/%.o: $(PROJECT_SRC_DIR)/%.c
	$(CXX) -c $(CXXFLAGS) -o [email protected] $<
	
.PHONY: clean
clean:
	rm -fr $(PROJECT_OBJ_DIR)/*.o
	rm -fr $(PROJECT_LIB_DIR)/$(TARGETS)

注意：空格及轉換字元的影響，拷貝到linux下，需要檢查多餘的空格字元（每行末尾）

Makefile編寫學習：

1、偽目標的作用：https://www.cnblogs.com/hnrainll/archive/2011/04/12/2014082.html；

2、Makefile中的命令字首作用：連結的2.3小節 https://www.cnblogs.com/wang_yb/p/3990952.html；

3、常用函式的查詢：https://blog.csdn.net/yangxuan0261/article/details/52060582；

4、gcc -MM kvm_main.c  

-MM作用是檢視kvm_main.c的依賴關係

輸出：kvm_main.o: kvm_main.c iodev.h coalesced_mmio.h async_pf.h；

5、自動變數

Makefile 中很多時候通過自動變數來簡化書寫, 各個自動變數的含義如下:

試試

6、gcc選項含義：

CFLAGS、CXXFLAGS、LDFLAGS與LIBS：https://blog.csdn.net/soaringlee_fighting/article/details/65448010

7、gcc編譯常用選項中     -Werror：它要求gcc將所有的警告當成錯誤進行處理；

                                     -fPIC選項：PIC指Position Independent Code。共享庫要求有此選項，以便實現動態連線

                                                        http://blog.sina.com.cn/s/blog_54f82cc201011op1.html

                                       ARFLAG := rcs：https://www.cnblogs.com/androidme/archive/2013/02/19/2917220.html

                                        -Dmacro：相當於C語言中的#define marcro巨集定義

8、$(MAKE)：就是預設的 make 這個命令的名稱（或者路徑），https://www.cnblogs.com/nosadness/p/5136560.html

                                    distclean：

                                                           $(MAKE) -C gbuni clean    

                                    進入gbuni目錄進行make clean