Makefile编写示例：构建一个库

1、目录结构如下：

[root@localhost libname]# tree
.
+-- include
¦   +-- headerA.h
¦   +-- headerB.h
+-- lib
+-- Makefile
+-- src
¦   +-- cppsrcA.cpp
¦   +-- cppsrcB.cpp
¦   +-- csrcA.c
¦   +-- csrcB.c
+-- test

4 directories, 7 files

2、Makefile内容为：

CC           = gcc
CXX          = g++
AR           = ar -r
RM           = rm -f
#INSTALL     = /usr/bin/install -m 644
#INSTALL_BIN = /usr/bin/install -m 755

# you can specify LIBTYPE=static when executing make, if you want to create a static library
ifeq ($(LIBTYPE),static)
  CFLAGS     = -I./include
  CXXFLAGS   = -I./include
else
  CFLAGS     = -I./include -fPIC
  CXXFLAGS   = -I./include -fPIC
  LDFLAGS    = -fPIC -shared
endif

C_SRC        = src/csrcA.c \
               src/csrcB.c
              
CXX_SRC      = src/cppsrcA.cpp \
               src/cppsrcB.cpp

SRC_DIR      = src
STATIC_OBJ_DIR =lib_obj/static_obj
DYNAMIC_OBJ_DIR=lib_obj/dynamic_obj
LIB_DIR      = lib

STATIC_LIB   = libname.a
DYNAMIC_LIB  = libname.so

ifeq ($(LIBTYPE),static)
  LIB_NAME   = $(STATIC_LIB)
  OBJS_DIR   = $(STATIC_OBJ_DIR)
else
  LIB_NAME   = $(DYNAMIC_LIB)
  OBJS_DIR   = $(DYNAMIC_OBJ_DIR)
endif

C_OBJS       = $(patsubst $(SRC_DIR)/%.c, $(OBJS_DIR)/%.o, $(C_SRC))
CXX_OBJS     = $(patsubst $(SRC_DIR)/%.cpp, $(OBJS_DIR)/%.o, $(CXX_SRC))
ALL_OBJS     = $(C_OBJS) $(CXX_OBJS)

INSTALL_PREFIX=/usr/local/libname

all: $(LIB_NAME)

$(STATIC_LIB): $(OBJS_DIR) $(ALL_OBJS)
    $(AR) $(LIB_DIR)/$@ $(ALL_OBJS)

$(DYNAMIC_LIB): $(OBJS_DIR) $(ALL_OBJS)
    $(CC) $(LDFLAGS) $(ALL_OBJS) -o $(LIB_DIR)/$@

$(OBJS_DIR):
    @if [ ! -d $(OBJS_DIR) ]; then \
        echo mkdir -p $(OBJS_DIR) ; \
        mkdir -p $(OBJS_DIR); \
    fi

$(C_OBJS):$(OBJS_DIR)/%.o:$(SRC_DIR)/%.c
    $(CC) $(CFLAGS) -c $< -o $@

$(CXX_OBJS):$(OBJS_DIR)/%.o:$(SRC_DIR)/%.cpp
    $(CXX) $(CXXFLAGS) -c $< -o $@
    
#install:
#uninstall:
#test:

.PHONY: cleanall clean
cleanall: clean
    $(RM) $(LIB_DIR)/$(STATIC_LIB) $(LIB_DIR)/$(DYNAMIC_LIB)
clean:
    $(RM) $(STATIC_OBJ_DIR)/*.o $(DYNAMIC_OBJ_DIR)/*.o

3、执行 make 和 make LIBTYPE=static 后的目录结构

[root@localhost libname]# tree
.
+-- include
¦   +-- headerA.h
¦   +-- headerB.h
+-- lib
¦   +-- libname.a
¦   +-- libname.so
+-- lib_obj
¦   +-- dynamic_obj
¦   ¦   +-- cppsrcA.o
¦   ¦   +-- cppsrcB.o
¦   ¦   +-- csrcA.o
¦   ¦   +-- csrcB.o
¦   +-- static_obj
¦       +-- cppsrcA.o
¦       +-- cppsrcB.o
¦       +-- csrcA.o
¦       +-- csrcB.o
+-- Makefile
+-- src
¦   +-- cppsrcA.cpp
¦   +-- cppsrcB.cpp
¦   +-- csrcA.c
¦   +-- csrcB.c
+-- test

7 directories, 17 files