[Fwd: Re: RFA: DW_OP_piece read path]

[Andrew Cagney <cagney@gnu.org>]

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It appears I sent this to the wrong address, sigh.

Andrew

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Andrew Cagney wrote:
> Elena,
> 
> This gets the read side of DW_OP_piece working, the write side is a lot 
> more work (in trying to code that side out I noticed that this tweak 
> would fix the immediate problem).
> 
> Tested on ppc, the printing of long-long in register values (as found in 
> store.exp) now passes.
> 
> I think with this in place we can (now that I've got some time again, 
> and my m/c stopped dieing) push out a quick 6.4.
> 
> ok?
> Andrew

Doh!


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2005-04-05  Andrew Cagney  <cagney@gnu.org>

	* dwarf2loc.c (dwarf2_evaluate_loc_desc): Handle DW_OP_piece
	reads.

Index: dwarf2loc.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2loc.c,v
retrieving revision 1.26
diff -p -u -r1.26 dwarf2loc.c
--- dwarf2loc.c	31 Mar 2005 19:58:24 -0000	1.26
+++ dwarf2loc.c	5 Apr 2005 21:56:51 -0000
@@ -305,11 +305,27 @@ dwarf2_evaluate_loc_desc (struct symbol 
   dwarf_expr_eval (ctx, data, size);
   if (ctx->num_pieces > 0)
     {
-      /* We haven't implemented splicing together pieces from
-         arbitrary sources yet.  */
-      error (_("The value of variable '%s' is distributed across several\n"
-             "locations, and GDB cannot access its value.\n"),
-             SYMBOL_NATURAL_NAME (var));
+      int i;
+      long offset = 0;
+      bfd_byte *contents;
+      retval = allocate_value (SYMBOL_TYPE (var));
+      contents = value_contents_raw (retval);
+      for (i = 0; i < ctx->num_pieces; i++)
+	{
+	  struct dwarf_expr_piece *p = &ctx->pieces[i];
+	  if (p->in_reg)
+	    {
+	      bfd_byte regval[MAX_REGISTER_SIZE];
+	      int gdb_regnum = DWARF2_REG_TO_REGNUM (p->value);
+	      get_frame_register (frame, gdb_regnum, regval);
+	      memcpy (contents + offset, regval, p->size);
+	    }
+	  else /* In memory?  */
+	    {
+	      read_memory (p->value, contents + offset, p->size);
+	    }
+	  offset += p->size;
+	}
     }
   else if (ctx->in_reg)
     {