prelude.c.tmpl: strip prefix

* template/prelude.c.tmpl (Prelude#translate): strip VPATH prefix
  from prelude names, so that srcdir diffrences do not make the
  generated code diffrent.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48490 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Wed Nov 19 10:07:57 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* template/prelude.c.tmpl (Prelude#translate): strip VPATH prefix
+	  from prelude names, so that srcdir diffrences do not make the
+	  generated code diffrent.
+
 Wed Nov 19 07:45:11 2014  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* win32/win32.c (rb_w32_write): should set the error of

template/prelude.c.tmpl

@@ -41,7 +41,7 @@ class Prelude
     idx = @preludes[filename]
     return idx if idx
     lines = []
-    result = [@preludes.size, filename, lines, sub]
+    result = [@preludes.size, @vpath.strip(filename), lines, sub]
     @vpath.foreach(filename) do |line|
       @preludes[filename] ||= result
       line.sub!(/(?:^|\s+)\#(?:$|\s.*)/, '')

tool/vpath.rb

@@ -79,4 +79,9 @@ class VPath
     end
     @list
   end
+
+  def strip(path)
+    prefix = list.map {|dir| Regexp.quote(dir)}
+    path.sub(/\A#{prefix.join('|')}(?:\/|\z)/, '')
+  end
 end