Re: RFA: assert that target_fetch_registers did its job

[Daniel Jacobowitz <drow@false.org>]

On Fri, Jul 23, 2004 at 05:59:11PM -0500, Jim Blandy wrote:
> 
> Does anyone see anything wrong with this?  Should it be an error, or a
> warning, instead of an internal error?  It seems to me that the error
> should be furnished by the target-specific code; if
> target_fetch_registers returns silently, it should have done its job.

It shouldn't be an error.  internal-error makes the most sense to me;
if we need to relax it while some broken target is worked on, then
it should be a warning or silent.

> But thread_db_fetch_registers doesn't follow that assumption.  In the
> threaded case, given any register number, it fetches the gprs, and the
> fprs, supplies them, and assumes its job is done.  It seems to me it
> sholud be calling register_valid_p (current_regcache, regno) to check
> that the register's value has really been supplied, and complaining if
> it hasn't.

I suggest we slay thread_db_fetch_registers.

Once upon a time, it served a purpose.  Now it is nothing but a source
of problems.  We could pass opaque cookies rather than register data
through the gregset structure - the interface doesn't really support
this but at least two of the five thread-db implementations I'm aware
of would.  Or we could just give up, use thread-db for nothing besides
finding new threads, and ask the LWP for its registers directly without
six or eight call frames of indirection.

-- 
Daniel Jacobowitz