------- Comment #2 from jakub at gcc dot gnu dot org 2010-05-13 21:48 -------
If I understand it well, we should:
--- dwarf2out.c 2010-05-13 23:36:24.000000000 +0200
+++ dwarf2out.c 2010-05-13 23:55:07.422464196 +0200
@@ -17094,10 +17094,19 @@ add_pure_or_virtual_attribute (dw_die_re
add_AT_unsigned (die, DW_AT_virtuality, DW_VIRTUALITY_virtual);
if (host_integerp (DECL_VINDEX (func_decl), 0))
- add_AT_loc (die, DW_AT_vtable_elem_location,
- new_loc_descr (DW_OP_constu,
- tree_low_cst (DECL_VINDEX (func_decl), 0),
- 0));
+ {
+ dw_loc_descr_ref loc;
+ HOST_WIDE_INT offset
+ = tree_low_cst (DECL_VINDEX (func_decl), 0)
+ * (POINTER_SIZE / BITS_PER_UNIT);
+ if (DWARF2_ADDR_SIZE == (POINTER_SIZE / BITS_PER_UNIT))
+ loc = new_loc_descr (DW_OP_deref, 0, 0);
+ else
+ loc = new_loc_descr (DW_OP_deref_size,
+ POINTER_SIZE / BITS_PER_UNIT, 0);
+ add_loc_descr (&loc, new_loc_descr (DW_OP_plus_uconst, offset, 0));
+ add_AT_loc (die, DW_AT_vtable_elem_location, loc);
+ }
/* GNU extension: Record what type this method came from originally.
* */
if (debug_info_level > DINFO_LEVEL_TERSE
The consumers should be pushing address of object, so we need to dereference
its first pointer to get at vtable + 8 resp. 16 and DECL_VINDEX is number of
pointers after that spot (seems to be the case even on ia64).
The problem is that gdb won't grok that, so we have a chicken-and-egg issue.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44126
