Re: [PATCH] Fix i386 FPU register conversion code

[Mark Kettenis <kettenis@wins.uva.nl>]

   Date: Mon, 30 Jul 2001 10:32:44 -0700
   From: Michael Snyder <msnyder@cygnus.com>

   Andrew Cagney wrote:
   > 
   > > Hmm, when I added the assertion, I was under the impression that if
   > > the virtual type wasn't a floating-point type it would be a GDB
   > > internal error, hence the gdb_assert.  However, this is probably not
   > > entirely true, since I now think that bogus debug information (e.g. a
   > > stab that says that  an integer variable that lives in a
   > > floating-point register) might trip the assertion.  Printing a warning
   > > and returning without doing anything is probably better.
   > 
   > By ``nothing'' I guess you mean do something like zero the destination
   > buffer :-)

   Right.  Silently fix it up, rather than call abort.
   Some errors don't warrant terminating a possibly long
   debug session.

I attached should address the concerns of both of you.  Checked in on
head and branch.

Mark


Index: ChangeLog
from  Mark Kettenis  <kettenis@gnu.org>

	* i386-tdep.c (i386_register_convert_to_virtual): Replace
	assertion with a warning if we're asked to convert towards a
	non-floating-point type.  Zero out the the buffer where the data
	is supposed to be stored in that case.

Index: i386-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/i386-tdep.c,v
retrieving revision 1.36
diff -u -p -r1.36 i386-tdep.c
--- i386-tdep.c 2001/07/28 17:03:38 1.36
+++ i386-tdep.c 2001/07/30 20:54:33
@@ -1046,7 +1046,13 @@ i386_register_convert_to_virtual (int re
   DOUBLEST d;
 
   /* We only support floating-point values.  */
-  gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
+  if (TYPE_CODE (type) != TYPE_CODE_FLT)
+    {
+      warning ("Cannot convert floating-point register value "
+	       "to non-floating-point type.");
+      memset (to, 0, TYPE_LENGTH (type));
+      return;
+    }
 
   /* First add the necessary padding.  */
   memcpy (buf, from, FPU_REG_RAW_SIZE);