* vm_insnhelper.c (vm_setup_method): should not enable tail call

optimization for frames with VM_FRAME_FLAG_FINISH.
  [ruby-dev:46065] [Bug #6901]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36771 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Wed Aug 22 11:23:35 2012  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* vm_insnhelper.c (vm_setup_method): should not enable tail call
+	  optimization for frames with VM_FRAME_FLAG_FINISH.
+	  [ruby-dev:46065] [Bug #6901]
+
 Wed Aug 22 11:20:47 2012  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* lib/rubygems/test_case.rb: run test with psych if exist.

test/ruby/test_optimization.rb

@@ -160,4 +160,25 @@ class TestRubyOptimization < Test::Unit::TestCase
     EOF
     assert_equal(9131, Tailcall.new.fact(3000).to_s.size, bug4082)
   end
+
+  def test_tailcall_with_block
+    bug6901 = '[ruby-dev:46065]'
+
+    option = {
+      tailcall_optimization: true,
+      trace_instruction: false,
+    }
+    iseq = RubyVM::InstructionSequence.new(<<-EOF, "Bug#6901", bug6901, nil, option).eval
+  def identity(val)
+    val
+  end
+
+  def delay
+    -> {
+      identity(yield)
+    }
+  end
+    EOF
+    assert_equal(123, delay { 123 }.call, bug6901)
+  end
 end

vm_insnhelper.c

@@ -510,7 +510,8 @@ vm_setup_method(rb_thread_t *th, rb_control_frame_t *cfp,
 
     sp = rsp + iseq->arg_size;
 
-    if (LIKELY(!(flag & VM_CALL_TAILCALL_BIT))) {
+    if (LIKELY(!(flag & VM_CALL_TAILCALL_BIT) ||
+	       VM_FRAME_TYPE_FINISH_P(th->cfp))) {
 	if (0) printf("local_size: %d, arg_size: %d\n",
 		      iseq->local_size, iseq->arg_size);