Re: [PATCH 2/2] Find the next matched trace file in 'tfile target'.

[Yao Qi <yao@codesourcery.com>]

On 02/27/2013 03:52 AM, Pedro Alves wrote:
> I'm confused on why this bit of the predicate
>
>   (tfnum == traceframe_number && tfnum == 0)
>
> is necessary.  traceframe_number is -1 when not looking
> at a traceframe yet, so "tfnum > traceframe_number"
> should be sufficient, no?
>

This condition was added to handle the case like this below:

(gdb) tfind 0
Found trace frame 0, tracepoint 2
(gdb) tfind tracepoint 2
Found trace frame 0, tracepoint 2

It is not necessary, and doesn't match the documentation.  We start from 
trace frame zero, and look for *next* frame from trace frame one.  This 
predicate can be removed.

> I find it clearer to move the frame skipping a bit higher
> up, even before the specific tfind tp/range/etc. matching.
> Doing it this way also avoids unnecessary read/lseek system
> calls done by tfile_get_traceframe_address.
>
> WDYT?
>

That makes sense to me.

>
>      Regression tested on x86_64 Fedora 17.
>
>      gdb/
>      2013-02-25  Yao Qi<yao@codesourcery.com>
>      	    Pedro Alves<palves@redhat.com>
>
>      	* tracepoint.c (tfile_trace_find): For tfind
>      	pc/tp/range/outside, look for the next trace frame instead of
>      	always starting from frame 0.

Committed.
-- 
Yao (齐尧)