On Fri, 30 Aug 2013 23:55:12 +0200, Mark Wielaard wrote:
> DW_OP_implicit_value and DW_OP_GNU_implicit_pointer already had
> their own special accessors (dwarf_getlocation_implicit_value
> and dwarf_getlocation_implicit_pointer), but it seemed consistent
> to include them in the new more generic accessors too.
So dwarf_getlocation_implicit_value and dwarf_getlocation_implicit_pointer can
be deprecated - that is removed from the .h interfaces? I haven't tried it
but with .symver also one could have only @version symbol without any
@@version symbol:
dwarf_getlocation_implicit_value@ELFUTILS_0.143
dwarf_getlocation_implicit_pointer@ELFUTILS_0.149
> --- a/libdw/dwarf_getlocation.c
> +++ b/libdw/dwarf_getlocation.c
> @@ -95,13 +95,15 @@ loc_compare (const void *p1, const void *p2)
> /* For each DW_OP_implicit_value, we store a special entry in the cache.
> This points us directly to the block data for later fetching. */
> static void
> -store_implicit_value (Dwarf *dbg, void **cache, Dwarf_Op *op,
> - unsigned char *data)
> +store_implicit_value (Dwarf *dbg, void **cache, Dwarf_Op *op)
> {
> struct loc_block_s *block = libdw_alloc (dbg, struct loc_block_s,
> sizeof (struct loc_block_s), 1);
> + const unsigned char *data = (const unsigned char *) op->number2;
> + Dwarf_Word blength; // Ignored, equal to op->number.
> + get_uleb128 (blength, data);
> block->addr = op;
> - block->data = data + op->number2;
> + block->data = (unsigned char *) data;
> block->length = op->number;
> (void) tsearch (block, cache, loc_compare);
> }
> @@ -412,11 +414,11 @@ __libdw_intern_expression (Dwarf *dbg, bool
> other_byte_order,
> if (unlikely (dbg == NULL))
> goto invalid;
>
> + newloc->number2 = (Dwarf_Word) data; /* start of block inc. len. */
> /* XXX Check size. */
> get_uleb128 (newloc->number, data); /* Block length. */
> if (unlikely ((Dwarf_Word) (end_data - data) < newloc->number))
> goto invalid;
> - newloc->number2 = data - block->data; /* Relative block offset. */
I think it breaks ABI. Dwarf_Op is a public structure. Layout of Dwarf_Op
for each of the operations is not explicitly documented but there are various
elfutils API details which are not completely documented.
I do not think it is such a concern but I do not want to be a joker.
> data += newloc->number; /* Skip the block. */
> break;
>
> @@ -437,17 +439,20 @@ __libdw_intern_expression (Dwarf *dbg, bool
> other_byte_order,
> break;
>
> case DW_OP_GNU_const_type:
> - /* XXX Check size. */
> - get_uleb128 (newloc->number, data);
> - if (unlikely (data >= end_data))
> - goto invalid;
> - newloc->number2 = *data++; /* Block length. */
> - if (unlikely ((Dwarf_Word) (end_data - data) < newloc->number2))
> - goto invalid;
> - /* The third operand is relative block offset:
> - newloc->number3 = data - block->data;
> - We don't support this at this point. */
> - data += newloc->number2; /* Skip the block. */
> + {
> + size_t size;
> +
> + /* XXX Check size. */
> + get_uleb128 (newloc->number, data);
> + if (unlikely (data >= end_data))
> + goto invalid;
> +
> + newloc->number2 = (Dwarf_Word) data; /* start of block inc. len. */
> + size = *data++;
> + if (unlikely ((Dwarf_Word) (end_data - data) < size))
> + goto invalid;
> + data += size; /* Skip the block. */
Likewise.
> + }
> break;
>
> default:
Thanks,
Jan
