Linux 内核Coding Style整理

switch (suffix) {
case 'G':
case 'g':

        mem <<= 30;
        break;
case 'M':
case 'm':
        mem <<= 20;
        break;
case 'K':
case 'k':
        mem <<= 10;
        /* fall through */
default:
        break;
}

if (condition) do_this;  /* bad example */

void fun(int a, int b, int c)
{
        if (condition)
                printk(KERN_WARNING "Warning this is a long printk with "
                       "3 parameters a: %u b: %u "
                       "c: %u \n", a, b, c);
        else
                next_statement;
}

int function(int x)
{   /* 这个大括号 { 另起了一行 */
        body of function
}

if (x is true) {  /* 这个大括号 { 不用另起一行 */
        we do y
}

if (condition)
        action();

if (condition) {
        do_this();
        do_that();
} else {
        otherwise();
}

s = sizeof(struct file);    /* good */
s = sizeof( struct file );  /* bad  */

char *linux_banner;
unsigned long long memparse(char *ptr, char **retptr);
char *match_strdup(substring_t *s);

count_active_users()  /* good */
cntusr()              /* cnt  */

int one_func(void)
{
        return 0;
}

int system_is_up(void)
{
        return system_state == SYSTEM_RUNNING;
}
EXPORT_SYMBOL(system_is_up);

int fun(int a)
{
        int result = 0;
        char *buffer = kmalloc(SIZE);

        if (buffer == NULL)
                return -ENOMEM;

        if (condition1) {
                while (loop1) {
                        ...
                }
                result = 1;
                goto out;
        }
        ...
        out:
                kfree(buffer);
                return result;
}

(defun c-lineup-arglist-tabs-only (ignored)
  "Line up argument lists by tabs, not spaces"
  (let* ((anchor (c-langelem-pos c-syntactic-element))
     (column (c-langelem-2nd-pos c-syntactic-element))
     (offset (- (1+ column) anchor))
     (steps (floor offset c-basic-offset)))
    (* (max steps 1)
       c-basic-offset)))

(add-hook 'c-mode-common-hook
          (lambda ()
            ;; Add kernel style
            (c-add-style
             "linux-tabs-only"
             '("linux" (c-offsets-alist
                        (arglist-cont-nonempty
                         c-lineup-gcc-asm-reg
                         c-lineup-arglist-tabs-only))))))

(add-hook 'c-mode-hook
          (lambda ()
            (let ((filename (buffer-file-name)))
              ;; Enable kernel mode for the appropriate files
              (when (and filename
                         (string-match (expand-file-name "~/src/linux-trees")
                                       filename))
                (setq indent-tabs-mode t)
                (c-set-style "linux-tabs-only")))))

config AUDIT
        bool "Auditing support"
        depends on NET
        help
          Enable auditing infrastructure that can be used with another
          kernel subsystem, such as SELinux (which requires this for
          logging of avc messages output).  Does not do system-call
          auditing without CONFIG_AUDITSYSCALL.

config SLUB
        depends on EXPERIMENTAL && !ARCH_USES_SLAB_PAGE_STRUCT
        bool "SLUB (Unqueued Allocator)"
        ...

config ADFS_FS_RW
        bool "ADFS write support (DANGEROUS)"
        depends on ADFS_FS
        ...

#define CONSTANT 0x12345

#define macrofun(a, b, c)             \
    do {                    \
        if (a == 5)            \
            do_this(b, c);        \
    } while (0)

#define CONSTANT 0x4000
#define CONSTEXP (CONSTANT | 3)

p = kmalloc(sizeof(*p), ...);

-*- mode: c -*-
or
/*
Local Variables:
compile-command: "gcc -DMAGIC_DEBUG_FLAG foo.c"
End:
*/

/* vim:set sw=8 noet */