fiddle/import.rb: suppress warnings

* ext/fiddle/lib/fiddle/import.rb (type_alias, handler): suppress
  "not initialized instance variable" warnings.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54534 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/fiddle/lib/fiddle/import.rb

@@ -63,6 +63,9 @@ module Fiddle
     include CParser
     extend Importer
 
+    attr_reader :type_alias
+    private :type_alias
+
     # Creates an array of handlers for the given +libs+, can be an instance of
     # Fiddle::Handle, Fiddle::Importer, or will create a new instance of
     # Fiddle::Handle using Fiddle.dlopen
@@ -102,7 +105,7 @@ module Fiddle
     def sizeof(ty)
       case ty
       when String
-        ty = parse_ctype(ty, @type_alias).abs()
+        ty = parse_ctype(ty, type_alias).abs()
         case ty
         when TYPE_CHAR
           return SIZEOF_CHAR
@@ -160,7 +163,7 @@ module Fiddle
 
     # Creates a global method from the given C +signature+.
     def extern(signature, *opts)
-      symname, ctype, argtype = parse_signature(signature, @type_alias)
+      symname, ctype, argtype = parse_signature(signature, type_alias)
       opt = parse_bind_options(opts)
       f = import_function(symname, ctype, argtype, opt[:call_type])
       name = symname.gsub(/@.+/,'')
@@ -184,7 +187,7 @@ module Fiddle
     # Creates a global method from the given C +signature+ using the given
     # +opts+ as bind parameters with the given block.
     def bind(signature, *opts, &blk)
-      name, ctype, argtype = parse_signature(signature, @type_alias)
+      name, ctype, argtype = parse_signature(signature, type_alias)
       h = parse_bind_options(opts)
       case h[:callback_type]
       when :bind, nil
@@ -213,7 +216,7 @@ module Fiddle
     #
     #   MyStruct = struct ['int i', 'char c']
     def struct(signature)
-      tys, mems = parse_struct_signature(signature, @type_alias)
+      tys, mems = parse_struct_signature(signature, type_alias)
       Fiddle::CStructBuilder.create(CStruct, tys, mems)
     end
 
@@ -221,7 +224,7 @@ module Fiddle
     #
     #   MyUnion = union ['int i', 'char c']
     def union(signature)
-      tys, mems = parse_struct_signature(signature, @type_alias)
+      tys, mems = parse_struct_signature(signature, type_alias)
       Fiddle::CStructBuilder.create(CUnion, tys, mems)
     end
 
@@ -257,7 +260,7 @@ module Fiddle
     #
     # Will raise an error if no handlers are open.
     def handler
-      @handler or raise "call dlload before importing symbols and functions"
+      (@handler ||= nil) or raise "call dlload before importing symbols and functions"
     end
 
     # Returns a new Fiddle::Pointer instance at the memory address of the given