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Re: bugs in remote.c
- To: Stan Shebs <shebs at cygnus dot com>
- Subject: Re: bugs in remote.c
- From: Quality Quorum <qqi at world dot std dot com>
- Date: Mon, 6 Dec 1999 19:54:46 -0500 (EST)
- cc: gdb at sourceware dot cygnus dot com
On Mon, 6 Dec 1999, Stan Shebs wrote:
>
> Date: Sun, 5 Dec 1999 14:17:31 -0500 (EST)
> From: Quality Quorum <qqi@world.std.com>
>
> It seems to me that minimal requirements to a stub should be:
>
> 1. Return empty on everything it does not understand.
> 2. Does not change its mind about understanding something while
> in the middle of operation. E.g. if it supports extended ops
> should also support restart.
> 3. Return 'ENN' if (a) fatal error occured or (b) memory error
> occured.
>
> It seems to me that it is an absolute minimum set of requirements,
> which will allow to complex stuff like queries to work properly.
>
> In general, that is what we've always expected from stubs. The
> "empty response to unsupported packet" rule, for instance, has been
> written down for a long time.
>
> It seems to me that people with uncompliant stubs should keep
> using gdb-4.18 or earlier, which are pretty decent debuggers
> anyway. Also, it seems like really simple thing to add
> something like 'old-remote' target which will lack new and shining
> stuff (e.g. extended ops, single register assignments and queries) but
> will be more tolerant towards old screwed up stubs.
>
> There are a *lot* of stubs in ROM and out in the field; so I'd be very
> reluctant to decree that they are no longer to be supported, even by
> using a different target name.
Let us give a different target name for a new thing.
> Instead, we should continue to tighten
> up the new standard, but allow exceptions if truly necessary, on a
> case-by-case basis. For instance, a couple letters can never be used
> for packet type because somebody already used them. That's OK, we
> have lots more letters available to us, and they're now explicitly
> stated as being reserved for future use.
>
> Actually, it would be interesting to find out about the lowest (sea
> floor?) and highest uses of GDB stubs (Mars?), smallest computer, most
> hostile environment, etc. Who's got the best story?
>
> Stan
>
Thanks,
Aleksey