* compile.c (iseq_compile_each): emit opt_str_freeze if the #freeze

  method is called on a static string literal with no arguments.

* defs/id.def (firstline): add freeze so idFreeze is available

* insns.def (opt_str_freeze): add opt_str_freeze instruction which
  pushes a frozen string literal without allocating a new object if
  String#freeze is not overriden

* string.c (Init_String): define String#freeze

* vm.c (vm_init_redefined_flag): define BOP_FREEZE on String class as
  a basic operation

* vm_insnhelper.h: ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43627 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/string.c b/string.c
index dbfce96788..ca73d41f98 100644
--- a/string.c
+++ b/string.c
@@ -8745,6 +8745,7 @@ Init_String(void)
     rb_define_method(rb_cString, "byteslice", rb_str_byteslice, -1);
     rb_define_method(rb_cString, "scrub", str_scrub, -1);
     rb_define_method(rb_cString, "scrub!", str_scrub_bang, -1);
+    rb_define_method(rb_cString, "freeze", rb_obj_freeze, 0);
 
     rb_define_method(rb_cString, "to_i", rb_str_to_i, -1);
     rb_define_method(rb_cString, "to_f", rb_str_to_f, 0);