static user probes

[Stan Cox]

Roland McGrath wrote:
>> helloprobes.d:
>> provider hello {
>>     probe printDemo(char*);
>> };
> 
> Is this part of dtrace script syntax, or is a "provider" file actually a
> disjoint syntax only used by the static-prep tool?

My understanding is that it is used as a static prep tool.
Collections of existing probes are known as providers, e.g. syscall 
provider, proc provider and pid provider.

> 
> What are the constraints on the types you can specify here?
> Anything that goes in a C99 prototype?
> 
> In script language, what type does "arg1" have?  Is it just a scalar, or
> could you do something to dereference that pointer?  

Based on what I have read for anything other than integer arguments I 
believe that it is necessary to use the copyin() or copyinstr() 
subroutines to dereference the pointer.