Re: Is the kernel compiler gcc by definition?
Andi Kleen (ak@muc.de)
16 Oct 1998 23:10:35 +0200
In article <vyz1zo8ydne.fsf@issan.cs.uni-dortmund.de>,
Andreas Schwab <schwab@LS5.informatik.uni-dortmund.de> writes:
> RHS Linux User <humbubba@raptor.cqi.com> writes:
> |> Is there a policy on what C constructs may be in the kernel?
> |> Or is gcc the de-facto definition of what kind of code is allowed?
> |> Or something else?
> |> Does anything in the normal arguments to gcc preclude the use of gcc's
> |> labels-as-values? ( computed gotos).
> |>
> |> I did a quick grep for goto * and got no hits.
> For most cases switch is good enough.
And computed goto turns off lots of useful optimizations in the compiler,
so it is probably not a good idea.
BTW The Linux kernel uses a feature related to computed gotos: label addresses.
They are useful to print the %eip/%pc in panic messages (e.g. used in
include/linux/skbuff.h)
-Andi
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