dtrace discuss - Jun 2010 - How does DTrace find the proc_t definition?

Hi,
While working on FreeBSD DTrace I came across this problem:

dtrace: failed to compile script callout.d:
"/usr/lib/dtrace/psinfo.d", line 53: operator -> cannot be applied
to a forward declaration: no struct proc definition is available

psinfo.d is FreeBSD specific (we don''t rely on procfs). Line 53 is:

translator psinfo_t < struct proc *T > {
..

The error message is clear, but the way to fix it isn''t clear to me
right now.

How does Solaris DTrace find the ''proc_t'' struct in
/usr/lib/dtrace/procfs.d ?

Thanks,
--
Rui Paulo

Rui Paulo wrote:
> Hi,
> While working on FreeBSD DTrace I came across this problem:
> 
> dtrace: failed to compile script callout.d:
"/usr/lib/dtrace/psinfo.d", line 53: operator -> cannot be applied
to a forward declaration: no struct proc definition is available
> 
> psinfo.d is FreeBSD specific (we don''t rely on procfs). Line 53
is:
> 
> translator psinfo_t < struct proc *T > {
> ..
> 
> The error message is clear, but the way to fix it isn''t clear to
me right now.
> 
> How does Solaris DTrace find the ''proc_t'' struct in
/usr/lib/dtrace/procfs.d ?
It gets it from the kernel''s symbol table using CTF.

-- 
James Carlson         42.703N 71.076W         <carlsonj at
workingcode.com>

On 9 Jun 2010, at 17:40, James Carlson wrote:
> Rui Paulo wrote:
>> Hi,
>> While working on FreeBSD DTrace I came across this problem:
>> 
>> dtrace: failed to compile script callout.d:
"/usr/lib/dtrace/psinfo.d", line 53: operator -> cannot be applied
to a forward declaration: no struct proc definition is available
>> 
>> psinfo.d is FreeBSD specific (we don''t rely on procfs). Line
53 is:
>> 
>> translator psinfo_t < struct proc *T > {
>> ..
>> 
>> The error message is clear, but the way to fix it isn''t clear
to me right now.
>> 
>> How does Solaris DTrace find the ''proc_t'' struct in
/usr/lib/dtrace/procfs.d ?
> 
> It gets it from the kernel''s symbol table using CTF.
Ok, thanks.

Regards,
--
Rui Paulo