iseq.c: mark parent iseq

* iseq.c (rb_iseq_mark): mark parent iseq to prevent dynamically
  generated iseq by eval from GC.  [ruby-core:72620] [Bug #11928]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53524 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed Jan 13 16:56:19 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* iseq.c (rb_iseq_mark): mark parent iseq to prevent dynamically
+	  generated iseq by eval from GC.  [ruby-core:72620] [Bug #11928]
+
 Wed Jan 13 03:42:58 2016  Eric Wong  <e@80x24.org>
 
 	* class.c (Init_class_hierarchy): resolve name for rb_cObject ASAP
@@ -9,12 +14,6 @@ Wed Jan 13 00:37:12 2016  Satoshi Ohmori  <sachin21dev@gmail.com>
 
 	* man/ruby.1: fix double word typo.  [Fix GH-1194]
 
-Wed Jan 13 00:16:47 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
-
-	* iseq.c (iseqw_mark): as wrapped iseq is isolated from the call
-	  stack, it needs to take care of its parent and ancestors, so
-	  that they do not become orphans.  [ruby-core:72620] [Bug #11928]
-
 Tue Jan 12 21:01:09 2016  Benoit Daloze  <eregontp@gmail.com>
 
 	* common.mk: update URL and name for the Ruby spec suite.

iseq.c

@@ -113,6 +113,7 @@ rb_iseq_mark(const rb_iseq_t *iseq)
 	rb_gc_mark(body->location.base_label);
 	rb_gc_mark(body->location.path);
 	RUBY_MARK_UNLESS_NULL(body->location.absolute_path);
+	RUBY_MARK_UNLESS_NULL((VALUE)body->parent_iseq);
     }
 
     if (FL_TEST(iseq, ISEQ_NOT_LOADED_YET)) {
@@ -711,11 +712,7 @@ rb_iseq_coverage(const rb_iseq_t *iseq)
 static void
 iseqw_mark(void *ptr)
 {
-    const rb_iseq_t *iseq = ptr;
     rb_gc_mark((VALUE)ptr);
-    while ((iseq = iseq->body->parent_iseq) != NULL) {
-	rb_gc_mark((VALUE)iseq);
-    }
 }
 
 static size_t

test/ruby/test_iseq.rb

@@ -185,4 +185,31 @@ class TestISeq < Test::Unit::TestCase
     labels = body.select {|op, arg| op == :branchnil}.map {|op, arg| arg}
     assert_equal(1, labels.uniq.size)
   end
+
+  def test_parent_iseq_mark
+    assert_separately([], <<-'end;')
+      ->{
+        ->{
+          ->{
+            eval <<-EOS
+              class Segfault
+                define_method :segfault do
+                  x = nil
+                  GC.disable
+                  1000.times do |n|
+                    n.times do
+                      x = (foo rescue $!).local_variables
+                    end
+                    GC.start
+                  end
+                  x
+                end
+              end
+            EOS
+          }.call
+        }.call
+      }.call
+      at_exit { assert_equal([:n, :x], Segfault.new.segfault.sort) }
+    end;
+  end
 end