Re: [PATCH 0/2] Better handling of slow remote transfers

[Gary Benson <gbenson@redhat.com>]

Pedro Alves wrote:
> On 08/12/2015 10:48 AM, Gary Benson wrote:
> > Joel Brobecker wrote:
> > > > At any rate, I think the default behaviour for 7.10 has to be
> > > > the default behaviour of 7.9 (given that, for example, we're
> > > > not going to make file transfer more adequately interruptible
> > > > for 7.10).
> > >
> > > That makes sense to me.
> > 
> > If we are to reset the default sysroot to "" then please
> > consider the series I posted that added the auto-target-prefix
> > functionality:
> > 
> >   https://sourceware.org/ml/gdb-patches/2015-07/msg00828.html
> 
> I'd really prefer not adding magic at the last minute to the 7.10
> release.  That would leave no breathing space to sort out further
> design mistakes, which I'm sure we'll trip on.

The only real "magic" that series adds is this:

+  if (target_filesystem_is_local ())
 ...
+  else if (auto_target_prefix && *gdb_sysroot == '\0')
+    {
+      /* Set the absolute prefix to "target:" for executable files
+	 and for shared libraries whose executable filename has a
+	 "target:"-prefix.  */
+      if (!is_solib
+	  || (exec_filename != NULL
+	      && is_target_filename (exec_filename)))
+	{
+	  sysroot = xstrdup (TARGET_FILENAME_PREFIX);
+	  make_cleanup (xfree, sysroot);
+	}
+    }

*If* it proves to be a problem then we can deprecate the set/show
auto-target-prefix boolean.

It seems like you're saying this series is a big change, but it's
really not: the core of it is that little snippet of logic, which
is easy enough to reason about:

  IF target filesystem is remote
     AND auto_target_prefix is enabled
     AND no sysroot is set
     AND (we're looking for an executable
          OR we're looking for a solib loaded by a target-prefixed executable):
       Prefix the filename with "target:"

It's certainly way less invasive a change than making transfers
interruptible would be.

> I think we need to unblock 7.10 as soon as possible so that 7.11
> with all the neat sysroot features happens sooner too.  :-)

Sure, but why not unblock it this way so that 7.10 users can have
the neat sysroot features, *if and only if* they use GDB in a way
that didn't make sense in 7.9?

Thanks,
Gary

-- 
http://gbenson.net/