Is "QTBuffer:size" a packet, or "QTBuffer:" plus an argument?

[Pedro Alves <palves at redhat dot com>]

On 02/15/2012 05:15 PM, Pedro Alves wrote:

>  (gdb) maint packet QTBuffer:size:ffffffff
>  sending: "QTBuffer:size:ffffffff"
>  received: "E01"
>  (gdb) FAIL: gdb.trace/circ.exp: maint packet QTBuffer:size:ffffffff

One question this raises is, is the right response to
QTBuffer:size:ffffffff, "E01", or an empty reply, indicating packet
not supported?  IOW, are QTBuffer:size and QTBuffer:circular two
different packets, or a single QTBuffer: packet with different
arguments?  This makes a difference if GDB is to gracefully detect
when the target side doesn't support QTBuffer:foo.

> QTBuffer:size is an undocumented packet, and gdbserver does not
> support it.  It is meant to change the trace buffer size.  I guess it
> was implemented in the old stub tracepoints were originally written
> for.  We'll probably end up supporting it, or something like it, at
> some point.

-- 
Pedro Alves