Re: [PATCH] BUG preserve registers

H. Peter Anvin
2002-02-09T20:01:13Z

Linus Torvalds wrote:

>
> On Sat, 9 Feb 2002, Andrew Morton wrote:
>
>>Is better, except the filename gets expanded multipe times into
>>the object file. How about:
>>
>>#define BUG() \
>> asm( "ud2\n" \
>> "\t.word %0\n" \
>> "\t.long %1\n" \
>> : : "i" (__LINE__), "i" (__FILE__))
>>
>
> Even better.
>
> That way you can actually totally remove the "verbose bug" config option,
> because even the verbose BUG's aren't actually using up any noticeable
> amounts of space.
>
> This is all assuming that gcc doesn't create the string for inline
> functions that aren't used, which it probably cannot, so maybe this
> doesn't work out.
>

Since gcc wouldn't even *see* a macro it didn't use, I find it hard to
imagine it would create anything.

However, you really want to do "asm volatile" rather than "asm"...

-hpa