fortran, debug: Fix up DW_AT_rank [PR103315]
For DW_AT_rank we were emitting
.uleb128 0x4 # DW_AT_rank
.byte 0x97 # DW_OP_push_object_address
.byte 0x23 # DW_OP_plus_uconst
.uleb128 0x1c
.byte 0x6 # DW_OP_deref
on 64-bit and
.uleb128 0x4 # DW_AT_rank
.byte 0x97 # DW_OP_push_object_address
.byte 0x23 # DW_OP_plus_uconst
.uleb128 0x10
.byte 0x6 # DW_OP_deref
on 32-bit. I think this is wrong, as dtype.rank field in the descriptor
has unsigned char type, not pointer type nor pointer sized integral.
E.g. if we have a
REAL :: a(..)
dummy argument, which is passed as a reference to the function descriptor,
we want to evaluate a->dtype.rank. The above DWARF expressions perform
*(uintptr_t *)(a + 0x1c)
and
*(uintptr_t *)(a + 0x10)
respectively. The following patch changes those to:
.uleb128 0x5 # DW_AT_rank
.byte 0x97 # DW_OP_push_object_address
.byte 0x23 # DW_OP_plus_uconst
.uleb128 0x1c
.byte 0x94 # DW_OP_deref_size
.byte 0x1
and
.uleb128 0x5 # DW_AT_rank
.byte 0x97 # DW_OP_push_object_address
.byte 0x23 # DW_OP_plus_uconst
.uleb128 0x10
.byte 0x94 # DW_OP_deref_size
.byte 0x1
which perform
*(unsigned char *)(a + 0x1c)
and
*(unsigned char *)(a + 0x10)
respectively.
2021-11-21 Jakub Jelinek <jakub@redhat.com>
PR debug/103315
* trans-types.c (gfc_get_array_descr_info): Use DW_OP_deref_size 1
instead of DW_OP_deref for DW_AT_rank.
(cherry picked from commit
da17c304e22ba256eba0b03710aa329115163b08)