forwardable/impl.rb

* lib/forwardable/impl.rb (_valid_method?, _compile_method):
  extract to separate implementation specific part.
  [ruby-core:78138] [Bug ruby#12938]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56848 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Author: nobu

ext/rubyvm/extconf.rb

@@ -0,0 +1 @@
+create_makefile("rubyvm")

ext/rubyvm/lib/forwardable/impl.rb

@@ -0,0 +1,19 @@
+# :stopdoc:
+module Forwardable
+  FILTER_EXCEPTION = ""
+
+  def self._valid_method?(method)
+    iseq = RubyVM::InstructionSequence.compile("().#{method}", nil, nil, 0, false)
+  rescue SyntaxError => e
+    false
+  else
+    iseq.to_a.dig(-1, 1, 1, :mid) == method.to_sym
+  end
+
+  def self._compile_method(src, file, line)
+    RubyVM::InstructionSequence.compile(src, file, file, line,
+               trace_instruction: false,
+               tailcall_optimization: true)
+      .eval
+  end
+end

lib/forwardable.rb

@@ -110,8 +110,10 @@
 # +delegate.rb+.
 #
 module Forwardable
+  require 'forwardable/impl'
+
   # Version of +forwardable.rb+
-  FORWARDABLE_VERSION = "1.1.0"
+  FORWARDABLE_VERSION = "1.2.0"
 
   @debug = nil
   class << self
@@ -195,14 +197,8 @@ def self._delegator_method(obj, accessor, method, ali)
       accessor = "#{accessor}()"
     end
 
-    vm = RubyVM::InstructionSequence
     method_call = ".__send__(:#{method}, *args, &block)"
-    if begin
-         iseq = vm.compile("().#{method}", nil, nil, 0, false)
-       rescue SyntaxError
-       else
-         iseq.to_a.dig(-1, 1, 1, :mid) == method.to_sym
-       end
+    if _valid_method?(method)
       loc, = caller_locations(2,1)
       pre = "_ ="
       mesg = "#{Module === obj ? obj : obj.class}\##{ali} at #{loc.path}:#{loc.lineno} forwarding to private method "
@@ -217,22 +213,17 @@ def self._delegator_method(obj, accessor, method, ali)
         end;
     end
 
-    line_no = __LINE__+1; str = "#{<<-"begin;"}\n#{<<-"end;"}"
+    _compile_method("#{<<-"begin;"}\n#{<<-"end;"}", __FILE__, __LINE__+1)
     begin;
       proc do
         def #{ali}(*args, &block)
           #{pre}
           begin
             #{accessor}
-          end#{method_call}
+          end#{method_call}#{FILTER_EXCEPTION}
         end
       end
     end;
-
-    vm.compile(str, __FILE__, __FILE__, line_no,
-               trace_instruction: false,
-               tailcall_optimization: true)
-      .eval
   end
 end
 

lib/forwardable/impl.rb

@@ -0,0 +1,24 @@
+# :stopdoc:
+module Forwardable
+  FILE_REGEXP = %r"#{Regexp.quote(File.dirname(__FILE__))}"
+  FILTER_EXCEPTION = <<-'END'
+
+        rescue ::Exception
+          $@.delete_if {|s| ::Forwardable::FILE_REGEXP =~ s} unless ::Forwardable::debug
+          ::Kernel::raise
+  END
+
+  def self._valid_method?(method)
+    catch {|tag|
+      eval("BEGIN{throw tag}; ().#{method}", binding, __FILE__, __LINE__)
+    }
+  rescue SyntaxError
+    false
+  else
+    true
+  end
+
+  def self._compile_method(src, file, line)
+    eval(src, nil, file, line)
+  end
+end