PE tests for Thread.detect_recursion

Author: chrisseaton

test/truffle/compiler/pe/pe.rb

@@ -88,6 +88,7 @@ def counter(example)
   require_relative 'core/encoding_pe'
   require_relative 'interop/interop_pe'
   require_relative 'truffle/engine_pe.rb'
+  require_relative 'truffle/thread_pe.rb'
   require_relative 'macro/pushing_pixels_pe.rb'
 
   if Truffle::Interop.mime_type_supported?('application/javascript')

test/truffle/compiler/pe/truffle/thread_pe.rb

@@ -0,0 +1,27 @@
+# Copyright (c) 2020 Oracle and/or its affiliates. All rights reserved. This
+# code is released under a tri EPL/GPL/LGPL license. You can use it,
+# redistribute it and/or modify it under the terms of the:
+# 
+# Eclipse Public License version 2.0, or
+# GNU General Public License version 2, or
+# GNU Lesser General Public License version 2.1.
+
+example "Thread.detect_recursion(Object.new) { }", false
+example "Thread.detect_recursion([]) { }", false
+example "Thread.detect_recursion({}) { }", false
+
+example "y = nil; Thread.detect_recursion(Object.new) { y = Thread.detect_recursion(Object.new) { } }; y", false
+example "x = Object.new; y = nil; Thread.detect_recursion(x) { y = Thread.detect_recursion(x) { } }; y", true
+
+def detect_recursion_recursive(method, object)
+  Thread.detect_recursion(object) do
+    object.send(method) do |child|
+      return detect_recursion_recursive(method, child)
+    end
+  end
+end
+
+example "detect_recursion_recursive(:each, [])", false
+example "detect_recursion_recursive(:each_value, {})", false
+example "a = []; a << a; detect_recursion_recursive(:each, a)", true
+example "a = {}; a[:a] = a; detect_recursion_recursive(:each_value, a)", true