How does NORET_TYPE works ? Post: 302161578

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Operating Systems Linux How does NORET_TYPE works ? Post 302161578 by amit4g on Friday 25th of January 2008 05:30:45 AM

01-25-2008

Registered User

How does NORET_TYPE works ?

Hi,

I was looking at the panic() code in linux kernel which is defined as:
51 /**
52 * panic - halt the system
53 * @fmt: The text string to print
54 *
55 * Display a message, then perform cleanups.
56 *
57 * This function never returns.
58 */
59
60 NORET_TYPE void panic(const char * fmt, ...)

where, NORET_TYPE is declared as
/*
753 * Ok, these declarations are also in <linux/kernel.h> but none of the
754 * ext3 source programs needs to include it so they are duplicated here.
755 */

# define NORET_TYPE /**/ <====

Please help me in understanding a #defined variable(NORET_TYPE here) which is not defined to anything.
I know that panic() function was designed in this way to not to return anything{in case of panic,there won't be anyone to catch the return value from panic() },but how does this work.
i think a program in user land having a #defined variable which is left blank will throw compile time error.how this is implemented in linux kernel ?
I don't know much about C,hence please excuse me if this is a stupid querry .

~amit

amit4g

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LEARN ABOUT DEBIAN

ctrlaltdel

CTRLALTDEL(8)						       System Administration						     CTRLALTDEL(8)

NAME

       ctrlaltdel - set the function of the Ctrl-Alt-Del combination

SYNOPSIS

       ctrlaltdel hard|soft

DESCRIPTION

       Based  on examination of the linux/kernel/sys.c code, it is clear that there are two supported functions that the Ctrl-Alt-Del sequence can
       perform: a hard reset, which immediately reboots the computer without calling sync(2) and without any other preparation; and a soft  reset,
       which sends the SIGINT (interrupt) signal to the init process (this is always the process with PID 1).  If this option is used, the init(8)
       program must support this feature.  Since there are now several init(8) programs in the Linux community, please consult	the  documentation
       for the version that you are currently using.

       ctrlaltdel is usually used in the /etc/rc.local file.

FILES

       /etc/rc.local

SEE ALSO

       simpleinit(8), init(8)

AUTHOR

       Peter Orbaek (poe@daimi.aau.dk)

AVAILABILITY

       The ctrlaltdel command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.

util-linux							   October 1993 						     CTRLALTDEL(8)

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