[PATCH] add BUG_ON to 2.4 #1

[PATCH] add BUG_ON to 2.4 #1

[Robert Love]

The following patch adds the BUG_ON (as seen on TV and 2.5) define to
the 2.4 kernel.  This will help in portability and back-porting from 2.5
to 2.4, plus BUG_ON is a nice optimization and aids readability.

For the unaware, BUG_ON(condition) calls bug on !condition, which is
marked unlikely().

This is the generalized arch-independent BUG_ON as in later 2.5 kernels.

Marcelo, please apply.

	Robert Love

--- linux-2.4.18-pre7/include/linux/kernel.h	Thu Jan 24 13:48:18 2002
+++ linux/include/linux/kernel.h	Fri Jan 25 17:53:54 2002
@@ -11,6 +11,7 @@
 #include <linux/linkage.h>
 #include <linux/stddef.h>
 #include <linux/types.h>
+#include <linux/compiler.h>
 
 /* Optimization barrier */
 /* The "volatile" is due to gcc bugs */
@@ -181,4 +182,5 @@
 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
 };
 
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
 #endif

Re: [PATCH] add BUG_ON to 2.4 #1

[John Levon]

On Fri, Jan 25, 2002 at 06:14:05PM -0500, Robert Love wrote:

> The following patch adds the BUG_ON (as seen on TV and 2.5) define to
> the 2.4 kernel.  This will help in portability and back-porting from 2.5
> to 2.4, plus BUG_ON is a nice optimization and aids readability.

I mentioned earlier today we need someone to step up and write a kcompat.h
for 2.5 stuff like minor() and the new remap_page_range().

I'll have to do this anyway for the stuff I use (I already have oodles of
2.2 stuff) but it would be nice to be able to use a "standard" header (and .c
if necessary)

regards
john
-- 
"ALL television is children's television."
	- Richard Adler 

Re: [PATCH] add BUG_ON to 2.4 #1

[Robert Love]

On Fri, 2002-01-25 at 22:17, John Levon wrote:

> I mentioned earlier today we need someone to step up and write a kcompat.h
> for 2.5 stuff like minor() and the new remap_page_range().
> 
> I'll have to do this anyway for the stuff I use (I already have oodles of
> 2.2 stuff) but it would be nice to be able to use a "standard" header (and .c
> if necessary)

Hopefully Marcelo will take this patch and we won't need BUG_ON, at
least, for 2.5->2.4 compatibility.

	Robert Love

Re: [PATCH] add BUG_ON to 2.4 #1

[John Levon]

On Fri, Jan 25, 2002 at 10:22:51PM -0500, Robert Love wrote:

> Hopefully Marcelo will take this patch and we won't need BUG_ON, at
> least, for 2.5->2.4 compatibility.

we still need it in kcompat.h so I can compile under 2.4.<random>,
and 2.2.<random> for that matter.

regards
john
-- 
"ALL television is children's television."
	- Richard Adler