Re: [rfc] Overflow in transfer-rate

[Daniel Jacobowitz <drow@false.org>]

On Mon, Jun 11, 2007 at 03:15:41PM +0200, Denis PILAT wrote:
> Andrew STUBBS wrote:
> > Denis PILAT wrote:
> >> In symfile.c/print_transfer_performance (), an overflow can occure when 
> >> data_count (see below) is a large number.
> >>
> >> I propose either the following 1st patch, or to pass to "%llu"into the 
> >> ui_out_field_fmt functino call, see the next patch proposal.
> >
> > I might also be worth taking a look at this proposal from some time ago 
> > http://www.cygwin.com/ml/gdb-patches/2006-10/msg00184.html
> >
> Well, it sounds like an internal ST discussion but I prefer the patch in your 
> link, it avoids overflow *and* prints transfer rate in a much clever way.

How about this version, then?  I left GDB/MI behavior unchanged, so
that this does not break GUIs.

-- 
Daniel Jacobowitz
CodeSourcery

2007-07-01  Ilko Iliev  <iliev@ronetix.at>
	    Daniel Jacobowitz  <dan@codesourcery.com>

	* symfile.c (print_transfer_performance): Avoid integer overflow.
	Use larger units.

Index: symfile.c
===================================================================
RCS file: /cvs/src/src/gdb/symfile.c,v
retrieving revision 1.187
diff -u -p -r1.187 symfile.c
--- symfile.c	18 Jun 2007 15:46:38 -0000	1.187
+++ symfile.c	1 Jul 2007 22:08:46 -0000
@@ -1947,7 +1947,7 @@ print_transfer_performance (struct ui_fi
 			    const struct timeval *start_time,
 			    const struct timeval *end_time)
 {
-  unsigned long time_count;
+  ULONGEST time_count;
 
   /* Compute the elapsed time in milliseconds, as a tradeoff between
      accuracy and overflow.  */
@@ -1957,9 +1957,23 @@ print_transfer_performance (struct ui_fi
   ui_out_text (uiout, "Transfer rate: ");
   if (time_count > 0)
     {
-      ui_out_field_fmt (uiout, "transfer-rate", "%lu",
-			1000 * (data_count * 8) / time_count);
-      ui_out_text (uiout, " bits/sec");
+      unsigned long rate = ((ULONGEST) data_count * 1000) / time_count;
+
+      if (ui_out_is_mi_like_p (uiout))
+	{
+	  ui_out_field_fmt (uiout, "transfer-rate", "%lu", rate * 8);
+	  ui_out_text (uiout, " bits/sec");
+	}
+      else if (rate < 1024)
+	{
+	  ui_out_field_fmt (uiout, "transfer-rate", "%lu", rate);
+	  ui_out_text (uiout, " bytes/sec");
+	}
+      else
+	{
+	  ui_out_field_fmt (uiout, "transfer-rate", "%lu", rate / 1024);
+	  ui_out_text (uiout, " KB/sec");
+	}
     }
   else
     {