From: Yusuke ENDOH <mame@...>
Date: 2008-05-22T23:20:20+09:00
Subject: [ruby-dev:34806] peephole_optimize ignores ADJUST

遠藤です。

以下で SEGV します。

$ ./ruby -e '
1.times do
  begin
  ensure
    redo unless false
  end
end
'
-e:4: [BUG] Segmentation fault
ruby 1.9.0 (2008-05-22 revision 16531) [i686-linux]

-- stack frame ------------
-- control frame ----------
c:0006 p:0001 s:302711808 b:0011 l:000005 d:000010 BLOCK  -e:4
c:0005 p:---- s:0011 b:0011 l:000010 d:000010 FINISH :class_eval
c:0004 p:---- s:0009 b:0009 l:000008 d:000008 CFUNC  :times
c:0003 p:0008 s:0006 b:0006 l:000005 d:000005 TOP    -e:2
c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH :private_class_method
c:0001 p:0000 s:0002 b:0002 l:000001 d:000001 TOP    <dummy toplevel>:17
---------------------------
Segmentation fault


ISEQ_ELEMENT_ADJUST が追加されたのに、peephole_optimize が
ISEQ_ELEMENT_INSN しか探さないことが原因のようです。


Index: compile.c
===================================================================
--- compile.c	(revision 16534)
+++ compile.c	(working copy)
@@ -1362,7 +1362,7 @@

     list = lobj->link.next;
     while (list) {
-	if (list->type == ISEQ_ELEMENT_INSN) {
+	if (list->type == ISEQ_ELEMENT_INSN || list->type == ISEQ_ELEMENT_ADJUST) {
 	    break;
 	}
 	list = list->next;
@@ -1376,7 +1376,7 @@
     LINK_ELEMENT *list = iobj->link.next;

     while (list) {
-	if (list->type == ISEQ_ELEMENT_INSN) {
+	if (list->type == ISEQ_ELEMENT_INSN || list->type == ISEQ_ELEMENT_ADJUST) {
 	    return list;
 	}
 	list = list->next;
@@ -1390,7 +1390,7 @@
     LINK_ELEMENT *list = iobj->link.prev;

     while (list) {
-	if (list->type == ISEQ_ELEMENT_INSN) {
+	if (list->type == ISEQ_ELEMENT_INSN || list->type == ISEQ_ELEMENT_ADJUST) {
 	    return list;
 	}
 	list = list->prev;

-- 
Yusuke ENDOH <mame@tsg.ne.jp>