未定義參照主，生成文件

Question

我具有簡單的結構爲：

sample2Make$ ls 

ADD DIV inc_print.h main.c makefile multiplication.o printer.o response.o subtraction.o addition.o division.o inc_resp.h main.o MUL printer.c response.c SUB 

其中ADD，DIV，SUB，MUL是含有用於所述操作的源文件和一個頭文件子目錄。生成文件是：

app: addition.o subtraction.o multiplication.o division.o response.o 
     gcc -o app response.o addition.o subtraction.o multiplication.o division.o 

response.o: inc_resp.h inc_print.h response.c printer.c main.c 
    gcc -c response.c printer.c main.c 

addition.o: ADD/inc_add.h ADD/addition.c 
    gcc -c ADD/addition.c 

subtraction.o: SUB/inc_sub.h SUB/subtraction.c 
    gcc -c SUB/subtraction.c 

multiplication.o: MUL/inc_mul.h MUL/multiplication.c 
    gcc -c MUL/multiplication.c 

division.o: DIV/inc_div.h DIV/division.c 
    gcc -c DIV/division.c 

頭文件只是聲明其各自的功能。現在寫命令後：

sample2Make$ make -f makefile 

我得到的輸出是：

gcc -c ADD/addition.c 
gcc -c SUB/subtraction.c 
gcc -c MUL/multiplication.c 
gcc -c DIV/division.c 
gcc -c response.c printer.c main.c 
gcc -o app addition.o subtraction.o multiplication.o division.o response.o 
/usr/lib/gcc/i686-linux-gnu/4.9/../../../i386-linux-gnu/crt1.o: In function `_start': 
/build/buildd/glibc-2.21/csu/../sysdeps/i386/start.S:111: undefined reference to `main' 
collect2: error: ld returned 1 exit status 
makefile:3: recipe for target 'app' failed 
make: *** [app] Error 1 

Answer 1

你錯過了包括printer.o和main.o在最後彙編語句，由於缺少參考main()，你的編譯器尖叫。

你的最後陳述應該像

gcc -o app addition.o subtraction.o multiplication.o division.o response.o printer.o main.o