Re: [RFC] Eliminate use of deprecated_register_bytes() from remote.c

[Kevin Buettner <kevinb@redhat.com>]

On Fri, 15 Apr 2005 17:37:58 -0400
Daniel Jacobowitz <drow@false.org> wrote:

> On Fri, Apr 15, 2005 at 02:32:45PM -0700, Kevin Buettner wrote:
> > This one seems almost obvious, but I'd like someone else to look it
> > over before I check it in...
> > 
> > 	* remote.c (init_remote_state): Eliminate use of
> > 	deprecated_register_bytes().
> 
> I'm pretty sure you need an if (regnum < NUM_REGS) on the second piece.

I agree that that's the right thing to do, but I'm not convinced that
will give us behavior equivalent to what we have now.  Consider the
following comment/code from regcache.c:

  /* FIXME: cagney/2002-05-22: Should only need to allocate space for
     the raw registers.  Unfortunately some code still accesses the
     register array directly using the global registers[].  Until that
     code has been purged, play safe and over allocating the register
     buffer.  Ulgh!  */
  descr->sizeof_raw_registers = descr->sizeof_cooked_registers;

The ``sizeof_raw_registers'' field is the value returned by
deprecated_register_bytes().  So, it seems to me that we're presently
setting rs->sizeof_g_packet to a value that's potentially larger than
need be.

I can think of no reason to continue to over-allocate space for g/G
packets in remote.c so I'm happy with this patch instead (which adds
the test that you wanted):

	* remote.c (init_remote_state): Eliminate use of
	deprecated_register_bytes().

Index: remote.c
===================================================================
RCS file: /cvs/src/src/gdb/remote.c,v
retrieving revision 1.184
diff -u -p -r1.184 remote.c
--- remote.c	15 Apr 2005 21:16:09 -0000	1.184
+++ remote.c	15 Apr 2005 22:53:38 -0000
@@ -248,10 +248,7 @@ init_remote_state (struct gdbarch *gdbar
   int regnum;
   struct remote_state *rs = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct remote_state);
 
-  if (deprecated_register_bytes () != 0)
-    rs->sizeof_g_packet = deprecated_register_bytes ();
-  else
-    rs->sizeof_g_packet = 0;
+  rs->sizeof_g_packet = 0;
 
   /* Assume a 1:1 regnum<->pnum table.  */
   rs->regs = GDBARCH_OBSTACK_CALLOC (gdbarch, NUM_REGS + NUM_PSEUDO_REGS,
@@ -266,8 +263,8 @@ init_remote_state (struct gdbarch *gdbar
       /* ...name = REGISTER_NAME (regnum); */
 
       /* Compute packet size by accumulating the size of all registers.  */
-      if (deprecated_register_bytes () == 0)
-        rs->sizeof_g_packet += register_size (current_gdbarch, regnum);
+      if (regnum < NUM_REGS)
+	rs->sizeof_g_packet += register_size (current_gdbarch, regnum);
     }
 
   /* Default maximum number of characters in a packet body. Many