[rfc] Avoid MIPS port breakage on large registers

[Daniel Jacobowitz <drow@false.org>]

I am about to post target-described register support for the MIPS
port.  One thing I noticed while testing it was that "info registers"
went off into the woods on O32 when I added an extra 64-bit register;
there's an unsigned loop until regsize - abi_regsize, which is
supposed to catch 32-bit registers on N64, but runs almost forever
given a 64-bit integer register on O32.  This patch just prints such
registers on their own row.

Any comments?  Otherwise, I'll commit along with the other register
description bits.

-- 
Daniel Jacobowitz
CodeSourcery

2007-05-21  Daniel Jacobowitz  <dan@codesourcery.com>

	* mips-tdep.c (mips_print_register): Remove unused ALL argument.
	(print_gp_register_row): Stop before printing a register bigger
	than the ABI register size.
	(mips_print_registers_info): Update call to mips_print_register.

---
 mips-tdep.c |   20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

Index: gdb/mips-tdep.c
===================================================================
--- gdb.orig/mips-tdep.c	2007-05-18 14:35:04.000000000 -0400
+++ gdb/mips-tdep.c	2007-05-18 14:58:34.000000000 -0400
@@ -3886,7 +3886,7 @@ mips_print_fp_register (struct ui_file *
 
 static void
 mips_print_register (struct ui_file *file, struct frame_info *frame,
-		     int regnum, int all)
+		     int regnum)
 {
   struct gdbarch *gdbarch = get_frame_arch (frame);
   gdb_byte raw_buffer[MAX_REGISTER_SIZE];
@@ -3964,6 +3964,18 @@ print_gp_register_row (struct ui_file *f
       if (TYPE_CODE (register_type (gdbarch, regnum)) ==
 	  TYPE_CODE_FLT)
 	break;			/* end the row: reached FP register */
+      /* Large registers are handled separately.  */
+      if (register_size (current_gdbarch, regnum)
+	  > mips_abi_regsize (current_gdbarch))
+	{
+	  if (col > 0)
+	    break;		/* End the row before this register.  */
+
+	  /* Print this register on a row by itself.  */
+	  mips_print_register (file, frame, regnum);
+	  fprintf_filtered (file, "\n");
+	  return regnum + 1;
+	}
       if (col == 0)
 	fprintf_filtered (file, "     ");
       fprintf_filtered (file,
@@ -3990,6 +4002,10 @@ print_gp_register_row (struct ui_file *f
       if (TYPE_CODE (register_type (gdbarch, regnum)) ==
 	  TYPE_CODE_FLT)
 	break;			/* end row: reached FP register */
+      if (register_size (current_gdbarch, regnum)
+	  > mips_abi_regsize (current_gdbarch))
+	break;			/* End row: large register.  */
+
       /* OK: get the data in raw format.  */
       if (!frame_register_read (frame, regnum, raw_buffer))
 	error (_("can't read register %d (%s)"), regnum, REGISTER_NAME (regnum));
@@ -4030,7 +4046,7 @@ mips_print_registers_info (struct gdbarc
       if (*(REGISTER_NAME (regnum)) == '\0')
 	error (_("Not a valid register for the current processor type"));
 
-      mips_print_register (file, frame, regnum, 0);
+      mips_print_register (file, frame, regnum);
       fprintf_filtered (file, "\n");
     }
   else