[PATCH] Don't handle blocks as exprlocs for DWARF version 4 or higher.
Mark Wielaard
mark@klomp.org
Thu Feb 18 13:40:36 GMT 2021
On Sat, 2021-02-13 at 23:46 +0100, Mark Wielaard wrote:
> Since DWARF version 4 blocks just contain bytes, trying to interpret
> them as exprlocs will most likely fail.
>
> * dwz.c (add_locexpr_dummy_dies): Only handle block as exprloc
> for cu_version < 4.
> (checksum_die): Likewise.
> (write_die): Likewise.
>
> https://sourceware.org/bugzilla/show_bug.cgi?id=26987
Ping. Any comments?
> dwz.c | 166 +++++++++++++++++++++++++++++---------------------------
> --
> 1 file changed, 84 insertions(+), 82 deletions(-)
>
> diff --git a/dwz.c b/dwz.c
> index d6b9df0..02fcd8c 100644
> --- a/dwz.c
> +++ b/dwz.c
> @@ -2913,43 +2913,44 @@ add_locexpr_dummy_dies (DSO *dso, dw_cu_ref
> cu, dw_die_ref die,
> if (form == DW_FORM_block1)
> {
> /* Old DWARF uses blocks instead of exprlocs. */
> - switch (attr)
> - {
> - case DW_AT_frame_base:
> - case DW_AT_location:
> - case DW_AT_data_member_location:
> - case DW_AT_vtable_elem_location:
> - case DW_AT_byte_size:
> - case DW_AT_bit_offset:
> - case DW_AT_bit_size:
> - case DW_AT_string_length:
> - case DW_AT_lower_bound:
> - case DW_AT_return_addr:
> - case DW_AT_bit_stride:
> - case DW_AT_upper_bound:
> - case DW_AT_count:
> - case DW_AT_segment:
> - case DW_AT_static_link:
> - case DW_AT_use_location:
> - case DW_AT_allocated:
> - case DW_AT_associated:
> - case DW_AT_data_location:
> - case DW_AT_byte_stride:
> - case DW_AT_rank:
> - case DW_AT_call_value:
> - case DW_AT_call_target:
> - case DW_AT_call_target_clobbered:
> - case DW_AT_call_data_location:
> - case DW_AT_call_data_value:
> - case DW_AT_GNU_call_site_value:
> - case DW_AT_GNU_call_site_data_value:
> - case DW_AT_GNU_call_site_target:
> - case DW_AT_GNU_call_site_target_clobbered:
> - if (read_exprloc_low_mem_phase1 (dso, die, ptr, len))
> - return 1;
> - default:
> - break;
> - }
> + if (cu->cu_version < 4)
> + switch (attr)
> + {
> + case DW_AT_frame_base:
> + case DW_AT_location:
> + case DW_AT_data_member_location:
> + case DW_AT_vtable_elem_location:
> + case DW_AT_byte_size:
> + case DW_AT_bit_offset:
> + case DW_AT_bit_size:
> + case DW_AT_string_length:
> + case DW_AT_lower_bound:
> + case DW_AT_return_addr:
> + case DW_AT_bit_stride:
> + case DW_AT_upper_bound:
> + case DW_AT_count:
> + case DW_AT_segment:
> + case DW_AT_static_link:
> + case DW_AT_use_location:
> + case DW_AT_allocated:
> + case DW_AT_associated:
> + case DW_AT_data_location:
> + case DW_AT_byte_stride:
> + case DW_AT_rank:
> + case DW_AT_call_value:
> + case DW_AT_call_target:
> + case DW_AT_call_target_clobbered:
> + case DW_AT_call_data_location:
> + case DW_AT_call_data_value:
> + case DW_AT_GNU_call_site_value:
> + case DW_AT_GNU_call_site_data_value:
> + case DW_AT_GNU_call_site_target:
> + case DW_AT_GNU_call_site_target_clobbered:
> + if (read_exprloc_low_mem_phase1 (dso, die, ptr, len))
> + return 1;
> + default:
> + break;
> + }
>
> return 0;
> }
> @@ -3736,50 +3737,51 @@ checksum_die (DSO *dso, dw_cu_ref cu,
> dw_die_ref top_die, dw_die_ref die)
> if (form == DW_FORM_block1)
> {
> /* Old DWARF uses blocks instead of exprlocs. */
> - switch (t->attr[i].attr)
> - {
> - case DW_AT_frame_base:
> - case DW_AT_location:
> - case DW_AT_data_member_location:
> - case DW_AT_vtable_elem_location:
> - case DW_AT_byte_size:
> - case DW_AT_bit_offset:
> - case DW_AT_bit_size:
> - case DW_AT_string_length:
> - case DW_AT_lower_bound:
> - case DW_AT_return_addr:
> - case DW_AT_bit_stride:
> - case DW_AT_upper_bound:
> - case DW_AT_count:
> - case DW_AT_segment:
> - case DW_AT_static_link:
> - case DW_AT_use_location:
> - case DW_AT_allocated:
> - case DW_AT_associated:
> - case DW_AT_data_location:
> - case DW_AT_byte_stride:
> - case DW_AT_rank:
> - case DW_AT_call_value:
> - case DW_AT_call_target:
> - case DW_AT_call_target_clobbered:
> - case DW_AT_call_data_location:
> - case DW_AT_call_data_value:
> - case DW_AT_GNU_call_site_value:
> - case DW_AT_GNU_call_site_data_value:
> - case DW_AT_GNU_call_site_target:
> - case DW_AT_GNU_call_site_target_clobbered:
> - if (die->die_ck_state != CK_BAD)
> - {
> - s = t->attr[i].attr;
> - die->u.p1.die_hash
> - = iterative_hash_object (s, die->u.p1.die_hash);
> - }
> - if (read_exprloc (dso, die, ptr, len, NULL))
> - return 1;
> - handled = true;
> - default:
> - break;
> - }
> + if (cu->cu_version < 4)
> + switch (t->attr[i].attr)
> + {
> + case DW_AT_frame_base:
> + case DW_AT_location:
> + case DW_AT_data_member_location:
> + case DW_AT_vtable_elem_location:
> + case DW_AT_byte_size:
> + case DW_AT_bit_offset:
> + case DW_AT_bit_size:
> + case DW_AT_string_length:
> + case DW_AT_lower_bound:
> + case DW_AT_return_addr:
> + case DW_AT_bit_stride:
> + case DW_AT_upper_bound:
> + case DW_AT_count:
> + case DW_AT_segment:
> + case DW_AT_static_link:
> + case DW_AT_use_location:
> + case DW_AT_allocated:
> + case DW_AT_associated:
> + case DW_AT_data_location:
> + case DW_AT_byte_stride:
> + case DW_AT_rank:
> + case DW_AT_call_value:
> + case DW_AT_call_target:
> + case DW_AT_call_target_clobbered:
> + case DW_AT_call_data_location:
> + case DW_AT_call_data_value:
> + case DW_AT_GNU_call_site_value:
> + case DW_AT_GNU_call_site_data_value:
> + case DW_AT_GNU_call_site_target:
> + case DW_AT_GNU_call_site_target_clobbered:
> + if (die->die_ck_state != CK_BAD)
> + {
> + s = t->attr[i].attr;
> + die->u.p1.die_hash
> + = iterative_hash_object (s, die->u.p1.die_hash);
> + }
> + if (read_exprloc (dso, die, ptr, len, NULL))
> + return 1;
> + handled = true;
> + default:
> + break;
> + }
> ptr += len;
> }
> else if (form == DW_FORM_exprloc)
> @@ -12392,7 +12394,7 @@ write_die (unsigned char *ptr, dw_cu_ref cu,
> dw_die_ref die,
> ptr += inptr - orig_ptr;
>
> /* Old DWARF uses blocks instead of exprlocs. */
> - if (form == DW_FORM_block1)
> + if (form == DW_FORM_block1 && cu->cu_version < 4)
> switch (reft->attr[i].attr)
> {
> case DW_AT_frame_base:
More information about the Dwz
mailing list