merge revision(s) 53383,55366: [Backport #12478]

	* lib/forwardable.rb (def_instance_delegator): adjust backtrace of
	  method body by tail call optimization.  adjusting the delegated
	  target is still done by deleting backtrace.

	* lib/forwardable.rb (def_single_delegator): ditto.

	* lib/forwardable.rb (Forwardable._delegator_method): extract
	  method generator and deal with non-module objects.
	  [ruby-dev:49656] [Bug #12478]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@57570 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

4 files changed, 99 insertions, 40 deletions

diff --git a/ChangeLog b/ChangeLog
index 76ca890b11..1d8773dae2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+Wed Feb  8 02:17:02 2017  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/forwardable.rb (Forwardable._delegator_method): extract
+	  method generator and deal with non-module objects.
+	  [ruby-dev:49656] [Bug #12478]
+
+Wed Feb  8 02:17:02 2017  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/forwardable.rb (def_instance_delegator): adjust backtrace of
+	  method body by tail call optimization.  adjusting the delegated
+	  target is still done by deleting backtrace.
+
+	* lib/forwardable.rb (def_single_delegator): ditto.
+
 Tue Jan 17 03:51:48 2017  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* compile.c (setup_args): duplicate splatting array if more
diff --git a/lib/forwardable.rb b/lib/forwardable.rb
index e20f5e3a31..e78b9ed1e0 100644
--- a/lib/forwardable.rb
+++ b/lib/forwardable.rb
@@ -178,33 +178,44 @@ module Forwardable
   #   q.push 23  #=> NoMethodError
   #
   def def_instance_delegator(accessor, method, ali = method)
-    accessor = accessor.to_s
-    if method_defined?(accessor) || private_method_defined?(accessor)
-      accessor = "#{accessor}()"
-    end
+    gen = Forwardable._delegator_method(self, accessor, method, ali)
 
-    line_no = __LINE__; str = %{
-      def #{ali}(*args, &block)
-        begin
-          #{accessor}.__send__(:#{method}, *args, &block)
-        rescue ::Exception
-          $@.delete_if{|s| ::Forwardable::FILE_REGEXP =~ s} unless ::Forwardable::debug
-          ::Kernel::raise
-        end
-      end
-    }
     # If it's not a class or module, it's an instance
-    begin
-      module_eval(str, __FILE__, line_no)
-    rescue
-      instance_eval(str, __FILE__, line_no)
-    end
-
+    (Module === self ? self : singleton_class).module_eval(&gen)
   end
 
   alias delegate instance_delegate
   alias def_delegators def_instance_delegators
   alias def_delegator def_instance_delegator
+
+  def self._delegator_method(obj, accessor, method, ali)
+    accessor = accessor.to_s unless Symbol === accessor
+
+    if Module === obj ?
+         obj.method_defined?(accessor) || obj.private_method_defined?(accessor) :
+         obj.respond_to?(accessor, true)
+      accessor = "#{accessor}()"
+    end
+
+    line_no = __LINE__+1; str = "#{<<-"begin;"}\n#{<<-"end;"}"
+    begin;
+      proc do
+        def #{ali}(*args, &block)
+          begin
+            #{accessor}
+          ensure
+            $@.delete_if {|s| ::Forwardable::FILE_REGEXP =~ s} if $@ and !::Forwardable::debug
+          end.__send__ :#{method}, *args, &block
+        end
+      end
+    end;
+
+    RubyVM::InstructionSequence
+      .compile(str, __FILE__, __FILE__, line_no,
+               trace_instruction: false,
+               tailcall_optimization: true)
+      .eval
+  end
 end
 
 # SingleForwardable can be used to setup delegation at the object level as well.
@@ -275,23 +286,9 @@ module SingleForwardable
   # the method of the same name in _accessor_).  If _new_name_ is
   # provided, it is used as the name for the delegate method.
   def def_single_delegator(accessor, method, ali = method)
-    accessor = accessor.to_s
-    if method_defined?(accessor) || private_method_defined?(accessor)
-      accessor = "#{accessor}()"
-    end
-
-    line_no = __LINE__; str = %{
-      def #{ali}(*args, &block)
-        begin
-          #{accessor}.__send__(:#{method}, *args, &block)
-        rescue ::Exception
-          $@.delete_if{|s| ::Forwardable::FILE_REGEXP =~ s} unless ::Forwardable::debug
-          ::Kernel::raise
-        end
-      end
-    }
+    gen = Forwardable._delegator_method(self, accessor, method, ali)
 
-    instance_eval(str, __FILE__, line_no)
+    instance_eval(&gen)
   end
 
   alias delegate single_delegate
diff --git a/test/test_forwardable.rb b/test/test_forwardable.rb
index a474e4ad76..f678ca4fc7 100644
--- a/test/test_forwardable.rb
+++ b/test/test_forwardable.rb
@@ -144,7 +144,7 @@ class TestForwardable < Test::Unit::TestCase
     end
   end
 
-  def test_def_single_delegator
+  def test_class_single_delegator
     %i[def_delegator def_single_delegator].each do |m|
       cls = single_forwardable_class do
         __send__ m, :@receiver, :delegated1
@@ -154,7 +154,7 @@ class TestForwardable < Test::Unit::TestCase
     end
   end
 
-  def test_def_single_delegators
+  def test_class_single_delegators
     %i[def_delegators def_single_delegators].each do |m|
       cls = single_forwardable_class do
         __send__ m, :@receiver, :delegated1, :delegated2
@@ -165,7 +165,7 @@ class TestForwardable < Test::Unit::TestCase
     end
   end
 
-  def test_single_delegate
+  def test_class_single_delegate
     %i[delegate single_delegate].each do |m|
       cls = single_forwardable_class do
         __send__ m, delegated1: :@receiver, delegated2: :@receiver
@@ -183,10 +183,50 @@ class TestForwardable < Test::Unit::TestCase
     end
   end
 
+  def test_obj_single_delegator
+    %i[def_delegator def_single_delegator].each do |m|
+      obj = single_forwardable_object do
+        __send__ m, :@receiver, :delegated1
+      end
+
+      assert_same RETURNED1, obj.delegated1
+    end
+  end
+
+  def test_obj_single_delegators
+    %i[def_delegators def_single_delegators].each do |m|
+      obj = single_forwardable_object do
+        __send__ m, :@receiver, :delegated1, :delegated2
+      end
+
+      assert_same RETURNED1, obj.delegated1
+      assert_same RETURNED2, obj.delegated2
+    end
+  end
+
+  def test_obj_single_delegate
+    %i[delegate single_delegate].each do |m|
+      obj = single_forwardable_object do
+        __send__ m, delegated1: :@receiver, delegated2: :@receiver
+      end
+
+      assert_same RETURNED1, obj.delegated1
+      assert_same RETURNED2, obj.delegated2
+
+      obj = single_forwardable_object do
+        __send__ m, %i[delegated1 delegated2] => :@receiver
+      end
+
+      assert_same RETURNED1, obj.delegated1
+      assert_same RETURNED2, obj.delegated2
+    end
+  end
+
   class Foo
     extend Forwardable
 
     def_delegator :bar, :baz
+    def_delegator :caller, :itself, :c
 
     class Exception
     end
@@ -197,6 +237,7 @@ class TestForwardable < Test::Unit::TestCase
       Foo.new.baz
     }
     assert_not_match(/\/forwardable\.rb/, e.backtrace[0])
+    assert_equal(caller(0, 1)[0], Foo.new.c[0])
   end
 
   class Foo2 < BasicObject
@@ -245,4 +286,11 @@ class TestForwardable < Test::Unit::TestCase
       class_exec(&block)
     end
   end
+
+  def single_forwardable_object(&block)
+    obj = Object.new.extend SingleForwardable
+    obj.instance_variable_set(:@receiver, RECEIVER)
+    obj.instance_eval(&block)
+    obj
+  end
 end
diff --git a/version.h b/version.h
index 108700cc30..e1d79ef234 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.3.3"
 #define RUBY_RELEASE_DATE "2017-02-08"
-#define RUBY_PATCHLEVEL 242
+#define RUBY_PATCHLEVEL 243
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 2