just a warning of gcc

[njmarshal]

It is a good ideal to compile the OS kernel with gcc
and nasm


but when I compile my .c file it alwaays return me a warning like this:

warning: no newline at end of file

I have a manual of gcc ,but when I look throught at it ,I can not find anything about the warning !

It is may not so important,because the .o file can be used,but it is so boring !

how can I make it.

[Candy]

add a new line at the end of the file... Your last line should always be blank, in windows-terms. In other words, you should terminate each line that does contain something with a newline.

If you editor strips off the last newlines get a better editor.

[Poseidon]

why is a newline at the end of the file actually needed?

[njmarshal]

thanks for your attention ,I have solve this warning !
but now I have a other thing,that I can not understand !

if I creat files as head.h and kernel.c
here is some code in head.h

Code: Select all

#define  byte unsigned char

and in kernel.c I write like this :

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#include "head.h"
//something else

byte   kkkkk=1;
 //others

and gcc compile the kernel.c,it brings to me a lot of error
but if I write this
unsigned char kkkk=1;
it is ok?

who can explain why "#define byte unsigned char"does not work as I think!or maybe I forget some parameters to gcc

thanks for your help ahead!

[Solar]

It isn't exactly needed - that's why it's a warning, instead of an error.

But imagine:

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// foo.h

void somecode() // no newline at end of this line

And:

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// main.c

#include <foo.h>
#include <bar.h>

If your preprocessor isn't smart, you might lose the [tt]#include <bar.h>[/tt] in the comment from [tt]foo.h[/tt]...

Just play it safe, end your files with a newline. Even if all you do it for is to satisfy the compiler. The compiler is your friend, not your enemy.

[Curufir]

Use typedef not define.

[njmarshal]

you mean typedef like this:

in head.h
typedef unsigned char byte

but it seems like not work !

[Solar]

Show us the GCC errors in question, and we might be better able to help.

[Pype.Clicker]

1. you should make sure your header file is processed correctly. It has to be somewhere in the "virtual path" to be seen by GCC.

2. you should have a ";" at the end of your typedef line

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typedef unsigned char byte;

3. seeing the error/warning gcc produces would indeed help alot.