Fix var tracking ICE due to reorg.

If during reorg we delete a code label, and as a result we decide to
delete all the code following that label, we hit this condition in
jump.c:delete_related_insns():

  if (was_code_label && prev && BARRIER_P (prev))

which passes and then we proceed to delete insns until we hit a
non-deleted code label.

During this traversal, we can end up deleting a CALL, but in doing so
we will leave the var tracking note for the call arguments around.

Later in dwarf2_var_location() we will ICE, because we can't find the
CALL when we search backwards for it.

The note searching scheme in the fix below is cribbed from code in
try_split() which has to handle a similar problem.

gcc/

	* jump.c (delete_related_insns): If we remove a CALL, make sure
	we delete it's NOTE_INSN_CALL_ARG_LOCATION note too.

From-SVN: r187606

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8d6c406354d592d42e348f8aa240b016da90011e..6715f30cb7a19b22400c16f939506688da549a2a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2012-05-16  David S. Miller  <davem@davemloft.net>
+
+       * jump.c (delete_related_insns): If we remove a CALL, make sure
+       we delete it's NOTE_INSN_CALL_ARG_LOCATION note too.
+
 2012-05-16  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
        PR tree-optimization/53217

diff --git a/gcc/jump.c b/gcc/jump.c
index 246fab02ff354e8585fd7743100b06b6d4ed2377..f5f644999d68147f56792707531417f8ebbabeb0 100644 (file)
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -1252,6 +1252,26 @@ delete_related_insns (rtx insn)
   if (next != 0 && BARRIER_P (next))
     delete_insn (next);
 
+  /* If this is a call, then we have to remove the var tracking note
+     for the call arguments.  */
+
+  if (CALL_P (insn)
+      || (NONJUMP_INSN_P (insn)
+         && GET_CODE (PATTERN (insn)) == SEQUENCE
+         && CALL_P (XVECEXP (PATTERN (insn), 0, 0))))
+    {
+      rtx p = insn;
+
+      for (p = NEXT_INSN (p);
+          p && NOTE_P (p);
+          p = NEXT_INSN (p))
+       if (NOTE_KIND (p) == NOTE_INSN_CALL_ARG_LOCATION)
+         {
+           remove_insn (p);
+           break;
+         }
+    }
+
   /* If deleting a jump, decrement the count of the label,
      and delete the label if it is now unused.  */