Re: [rfa/6.0] Fix a thinko in dwarf2loc

[Daniel Jacobowitz <drow@mvista.com>]

On Thu, Sep 11, 2003 at 01:24:57PM -0400, Elena Zannoni wrote:
> Daniel Jacobowitz writes:
>  > On Tue, Sep 09, 2003 at 06:59:52PM -0400, Andrew Cagney wrote:
>  > > > > >  > > > > +  return baton.needs_frame || ctx->in_reg;
>  > > > > >  > > > >  }
>  > > > > >  > > > >  
>  > > > > > 
>  > > > > > Hmmm, the ctx just got freed, you cannot dereference it. Need to use a
>  > > > > 
>  > > > > Eek, I'm embarassed.  You are so right.
>  > > > > 
>  > > > > > local variable.  What you are really saying here is that the
>  > > > > > needs_frame variable is not sufficient to describe what's needed. Can
>  > > > > > the case be added, so that needs_frame becomes OK? Proabably you
>  > > > > > need another need_frame_* function.
>  > > > > 
>  > > > > No, I can't.  The needs_frame_* functions are hooks for things which
>  > > > > are external to the expression evaluator - concepts like "object" and
>  > > > > "thread local storage address" which require information.  But the
>  > > > > evaluator won't actually try to read from the register when parsing a
>  > > > > DW_OP_reg1; it just sets in_reg.
>  > > >
>  > > >Oh, ok, I guess save ctx->in_reg in a local variable then.
>  > > >
>  > > >elena
>  > > 
>  > > Thanks for picking this up.  So there's no confusion I'm also ok with 
>  > > this on the branch.
>  > 
>  > Thank you both.  Checked in.
> 
> Just for completeness, can you post the patch?
> 
> thanks
> elena

Oops.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

2003-09-11  Daniel Jacobowitz  <drow@mvista.com>

	* dwarf2loc.c (dwarf2_loc_desc_needs_frame): Variables in a
	register do need a frame.

Index: dwarf2loc.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2loc.c,v
retrieving revision 1.12
diff -u -p -r1.12 dwarf2loc.c
--- dwarf2loc.c	22 Jul 2003 18:24:42 -0000	1.12
+++ dwarf2loc.c	11 Sep 2003 14:57:16 -0000
@@ -304,6 +304,7 @@ dwarf2_loc_desc_needs_frame (unsigned ch
 {
   struct needs_frame_baton baton;
   struct dwarf_expr_context *ctx;
+  int in_reg;
 
   baton.needs_frame = 0;
 
@@ -316,9 +317,11 @@ dwarf2_loc_desc_needs_frame (unsigned ch
 
   dwarf_expr_eval (ctx, data, size);
 
+  in_reg = ctx->in_reg;
+
   free_dwarf_expr_context (ctx);
 
-  return baton.needs_frame;
+  return baton.needs_frame || in_reg;
 }
 
 static void