Re: [RFA]: LOC_COMPUTED + abstracted dwarf2 evaluator, again

Jim Blandy
2002-07-09T21:00:37Z

Daniel Berlin <dberlin@dberlin.org> writes:
> + /* Evaluate a location description, given in THEBLOCK, in the
> + context of frame FRAME. */
> + static struct value *
> + evaluate_loc_desc (struct symbol *var, struct frame_info *frame,
> + struct dwarf_block *theblock, struct type *type)
> + {
> + CORE_ADDR result;
> + struct value * retval;
> + struct dwarf_expr_baton *baton = xmalloc (sizeof (struct dwarf_expr_baton));
> + struct dwarf_expr_context *ctx;
> +
> + retval = allocate_value(type);
> + baton->var = var;
> + baton->frame = frame;
> +
> + VALUE_LVAL (retval) = lval_memory;
> + VALUE_BFD_SECTION (retval) = SYMBOL_BFD_SECTION (var);
> +
> + ctx = new_dwarf_expr_context ();
> + ctx->read_reg_baton = baton;
> + ctx->read_reg = dwarf_expr_read_reg;
> + ctx->read_mem_baton = baton;
> + ctx->read_mem = dwarf_expr_read_mem;
> + ctx->get_frame_base_baton = baton;
> + ctx->get_frame_base = dwarf_expr_frame_base;
> + ctx->error = error;
> +
> + dwarf_expr_eval (ctx, theblock->data, theblock->size);
> +
> + if (ctx->in_reg)
> + {
> + store_typed_address (VALUE_CONTENTS_RAW (retval),
> + SYMBOL_TYPE (var), dwarf_expr_fetch (ctx, 0));
> + VALUE_LVAL (retval) = not_lval;
> + }
> + else
> + {
> + result = dwarf_expr_fetch (ctx, 0);
> + VALUE_LAZY (retval) = 1;
> + VALUE_ADDRESS (retval) = result;
> + }

This looks wrong. If evaluating the Dwarf location expression yields
an `in_reg' result, shouldn't the value be an lval_register, with its
the address set to the register number?

I think the evaluator is confused in this regard, too; see my upcoming
post about that.