[PATCH][low-mem] Fix DW_OP_GNU_parameter_ref handling in read_exprloc

[Tom de Vries <tdevries@suse.de>]

Hi,

Function read_exprloc contains a loop that marks all parents of a
DW_OP_GNU_parameter_ref reference with CK_BAD.  The loop however has no
private loop variable, so the ref variable, initially pointing to the
referenced DIE, ends up after the loop pointing to the root parent of the
reference instead.  Consequently, the code after the loop, intended to be
executed for the referenced DIE, is instead executed for the root parent of
the referenced DIE.

Fix this by moving the loop alap.

OK for trunk?

Thanks,
- Tom

[low-mem] Fix DW_OP_GNU_parameter_ref handling in read_exprloc

2019-02-14  Tom de Vries  <tdevries@suse.de>

	PR dwz/24195
	* dwz.c (read_exprloc): Move loop marking parents with CK_BAD alap.

---
 dwz.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/dwz.c b/dwz.c
index d348418..6e6b6fb 100644
--- a/dwz.c
+++ b/dwz.c
@@ -1492,6 +1492,15 @@ read_exprloc (DSO *dso, dw_die_ref die, unsigned char *ptr, size_t len,
 	    }
 	  if (op == DW_OP_call2)
 	    ref->die_op_call2_referenced = 1;
+	  if (unlikely (low_mem))
+	    {
+	      ref->die_referenced = 1;
+	      /* As .debug_loc adjustment is done after
+		 write_info finishes, we need to keep the referenced
+		 DIEs around uncollapsed.  */
+	      if (need_adjust)
+		ref->die_intercu_referenced = 1;
+	    }
 	  if (ref->die_ck_state == CK_KNOWN)
 	    {
 	      ref->die_ck_state = CK_BAD;
@@ -1504,15 +1513,6 @@ read_exprloc (DSO *dso, dw_die_ref die, unsigned char *ptr, size_t len,
 	    }
 	  else
 	    ref->die_ck_state = CK_BAD;
-	  if (unlikely (low_mem))
-	    {
-	      ref->die_referenced = 1;
-	      /* As .debug_loc adjustment is done after
-		 write_info finishes, we need to keep the referenced
-		 DIEs around uncollapsed.  */
-	      if (need_adjust)
-		ref->die_intercu_referenced = 1;
-	    }
 	  die->die_ck_state = CK_BAD;
 	  if (need_adjust)
 	    *need_adjust = true;