Re: [RFA] Remote symbol look-up (resubmission)

[Michael Snyder <msnyder at cygnus dot com>]

Andrew Cagney wrote:
> 
> > Are you saying that there is going to need to be an extra parameter (the
> >> shared library name) added to the target->gdb symbol request on Solaris?
> >
> >
> > No, I'm saying it could potentially be useful to pass back the filename.
> > Not that I think it is necessary.  The underlying mechanism that would
> > use this method on Solaris has a symbol-file-name argument.  We don't
> > currently use it.  Someday we might.  Just keeping the option open.
> 
> In that case I'd prefer at this point to leave the the symbol-file
> passing out.  Instead just stick to a single simple qSymbol packet.  The
> behavour would be:
> 
>         To start a transaction sequence:
> 
>                 -> qSymbol
> 
>         It could even be:
> 
>                 -> qSymbol::
> 
>         If you want simplicity and consistency.
> 
>         The reply would be as you proposed:
> 
>                 <- ""
>                         Not recognized
>                 <- "OK"
>                         Recognized but not now
>                 <- <the-I-want-a-symbol-address>
>                         As you've described
> 
>         From then on it is:
> 
>                 -> qSymbol:<addr>:<symbol>
> 
> I don't think it is a good idea to try to include a mechanism for
> passing back and forth the name of an object file until there is a
> demonstrated need for such a feature.
> 
> The reason for this is that, in the past GDB has incorporated what look
> like very reasonable idea's only to find that, when someone uses them,
> they are insufficient.

Andrew, if I have to change the QSymbol:value:name message from a
Q to a q, it is going to cause me non-trivial grief and code rewriting.
Are you going to insist on this?  To me it seems like a "set" message,
not a "query" message.  It is telling the target that symbol <name>
has value <value>, not asking the target something.

I need the first message that opens the dialogue to be unambiguously
unique, so that I know that I have to request the _first_ unknown
symbol, rather than the _next_ unknown symbol.  I don't want the
message that says "start requesting symbols" to be the same as the
message that says "here's your next symbol, and by the way you may
request another".

Michael