如何創建一個合適的Makefile，並確定依賴關係的順序？

Question

我有5個文件，我必須使用makefile來創建一個文件。

student.c has #include "student.h" 

linkedlist.c has #include "linkedlist.h" 

and main has #include "linkedlist.h" and #include "student.h" 

student.c 
student.h 
linkedlist.c 
linkedlist.h 
main.c 

我不知道該命令是否重要，以解決依賴關係。 我想我真正要問的是底層依賴意味着什麼？ 有人可以澄清如何正確使用makefile爲未來的項目？

Answer 1

基本上，你需要知道的是：

#You can make some const variables like `CC = gcc` 
#and use them in the Makefile like that `$(CC)` 
#(you basically wrap the variable with brackets and 
#put a dollar sign before it). 

CC = gcc 

#The order is crutial in a makefile. 

# First of all you want to compile `main` using objects 
# which are yet to be linked. 
main: student.o linkedlist.o 
    # Line below is a command 
    # that is already well known to you I guess: "gcc -o main ..." 
    $(CC) -o main student.o linkedlist.o 

# If makefile doesn't have the newest version of a .o file, 
# then it goes to lines below 
# to find out, how can it obtain the newest version 
# of student.o or linkedlist.o 

# This is how it can produce the .o file: 
student.o: student.c 
    $(CC) -c student.c 
    # -c flag is crutial here, because it means that you want to create 
    # a .o (object) file. Not an executable program. 

# Same with linkedlist.c: 
linkedlist.o: linkedlist.c 
    $(CC) -c linkedlist.c 

我希望它的作品，我沒有測試它。如果我犯了任何錯誤，請糾正我。

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