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

Daniel Jacobowitz
2003-09-11T17:17:10Z

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