Re: [RFA]: File-I/O patch, Documentation

[Corinna Vinschen <vinschen@redhat.com>]

On Thu, Feb 27, 2003 at 06:07:06PM -0500, Andrew Cagney wrote:
> I think the only problem here is the need for two small, simple but 
> concrete examples:
> 
> - the target doing a write() call
> 
> - the user entering CNTRL-C and a demonstration of one of the edge cases

Ok.

> My one concern with the protocol spec is with this structure.  The size 
> of those various types is target compiler dependent yet the 
> implementation assumes specific sizes.

Sure.  The sizes are chosen so that they are very likely big enough
to match all hosts and targets for... well... at least a long time.

> c99 (what ever the standard) formalized a number of explicitly sized 
> types (int32 et.al. I believe).  I think this table should be specified 
> using those types.  The alternative is to generalize the 
> sim/common/sim-types.h file and then specify the sizes using that.

I don't think so.  The protocol is more or less self-contained.  All
definitions are based on the assumption, that you'll never find a
really matching combination of values as they are defined on all
machines.  Looking into the fileio code you'll see, that gdb has a
couple of functions which transform all protocol datatypes to host
datatypes and all protocol values to host values and vice versa.
This is done that way to be totally independent from other sources of
definition (especially machine dependent definitions).

It's *expected* that the gdb plugin on the target side is doing the
same.

> The time unit of st_*time should be defined.

Second since epoche but you're right, it should be mentioned.

> The byte order of all the values should be defined.

It is.  Quote from the text:

  Structured data which is transferred using a memory read or write
  packet as e.g. a struct stat is expected to be in a protocol specific
  format with all numerical multibyte datatypes being big endian.

> The reference to B.1 should be removed.

Nope.

Corinna

-- 
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.
mailto:vinschen@redhat.com