Re: PATCH: Fix DW_OP_deref for DW_TAG_formal_parameter

[Daniel Jacobowitz <drow@mvista.com>]

On Thu, Jul 31, 2003 at 09:12:59AM -0700, H. J. Lu wrote:
> On Thu, Jul 31, 2003 at 11:48:21AM -0400, Daniel Jacobowitz wrote:
> > On Thu, Jul 31, 2003 at 08:44:05AM -0700, H. J. Lu wrote:
> > > On Wed, Jul 30, 2003 at 08:27:53PM -0400, Daniel Jacobowitz wrote:
> > > > On Wed, Jul 30, 2003 at 05:23:06PM -0700, H. J. Lu wrote:
> > > > > On Wed, Jul 30, 2003 at 05:56:12PM -0400, Daniel Jacobowitz wrote:
> > > > > > On Wed, Jul 30, 2003 at 02:54:21PM -0700, H. J. Lu wrote:
> > > > > > > Does DW_OP_deref work correctly with gdb?
> > > > > > 
> > > > > > That depends on the context.  Things that use decode_locdesc, probably
> > > > > > not.  As we find time, things are being converted to the full
> > > > > > expression evaluator.  Location descriptions and frame bases should
> > > > > > work.
> > > > > 
> > > > > I don't think it does. Intel Fortran compiler generartes DW_OP_deref.
> > > > > I got
> > > > 
> > > > Location descriptions for parameters may not work fully.  Feel free to
> > > > fix it, or to investigate the reasons why more thoroughly - search for
> > > > LOC_COMPUTED_ARG, but I don't even think we generate those yet.
> > > > 
> > > 
> 
> > Please look more closely at what I suggested, and at how DW_OP_deref
> > works for DW_TAG_variable (as opposed to DW_TAG_formal_parameter).  All
> > of the above should be turned into LOC_COMPUTED_ARG.
> > 
> 
> Thanks. This patch works for me.

Could you test this alternative?  The goal is to eliminate calls to
decode_locdesc.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

2003-07-31  Daniel Jacobowitz  <drow@mvista.com>

	* dwarf2read.c (new_symbol): Use var_decode_location for parameters.

Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.98
diff -u -p -r1.98 dwarf2read.c
--- dwarf2read.c	22 Jul 2003 15:41:59 -0000	1.98
+++ dwarf2read.c	31 Jul 2003 16:21:04 -0000
@@ -5207,32 +5207,10 @@ new_symbol (struct die_info *die, struct
 	  attr = dwarf_attr (die, DW_AT_location);
 	  if (attr)
 	    {
-	      SYMBOL_VALUE (sym) =
-		decode_locdesc (DW_BLOCK (attr), objfile, cu_header);
-	      if (isreg)
-		{
-		  SYMBOL_CLASS (sym) = LOC_REGPARM;
-		  SYMBOL_VALUE (sym) = 
-		    DWARF2_REG_TO_REGNUM (SYMBOL_VALUE (sym));
-		}
-	      else if (offreg)
-		{
-		  if (isderef)
-		    {
-		      if (basereg != frame_base_reg)
-			dwarf2_complex_location_expr_complaint ();
-		      SYMBOL_CLASS (sym) = LOC_REF_ARG;
-		    }
-		  else
-		    {
-		      SYMBOL_CLASS (sym) = LOC_BASEREG_ARG;
-		      SYMBOL_BASEREG (sym) = DWARF2_REG_TO_REGNUM (basereg);
-		    }
-		}
-	      else
-		{
-		  SYMBOL_CLASS (sym) = LOC_ARG;
-		}
+	      var_decode_location (attr, sym, objfile, cu_header);
+	      /* FIXME drow/2003-07-31: Is LOC_COMPUTED_ARG necessary?  */
+	      if (SYMBOL_CLASS (sym) == LOC_COMPUTED)
+		SYMBOL_CLASS (sym) = LOC_COMPUTED_ARG;
 	    }
 	  attr = dwarf_attr (die, DW_AT_const_value);
 	  if (attr)