* 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

7 files changed, 49 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 9ba9221a08..d80d3953cd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,23 @@
+Sun Nov 10 06:14:39 2013  Charlie Somerville  <charliesome@ruby-lang.org>
+
+	* 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
+
+	[Feature #8992] [ruby-core:57705]
+
 Sun Nov 10 01:34:14 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (vm_malloc_increase): sweep immediately on GC due to malloc().
diff --git a/compile.c b/compile.c
index f3f5f2d75a..00ae3011e7 100644
--- a/compile.c
+++ b/compile.c
@@ -4314,6 +4314,17 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 	break;
       }
       case NODE_CALL:
+	if (node->nd_recv && nd_type(node->nd_recv) == NODE_STR &&
+	    node->nd_mid == idFreeze && node->nd_args == NULL)
+	{
+	    VALUE str = rb_fstring(node->nd_recv->nd_lit);
+	    iseq_add_mark_object(iseq, str);
+	    ADD_INSN1(ret, line, opt_str_freeze, str);
+	    if (poped) {
+		ADD_INSN(ret, line, pop);
+	    }
+	    break;
+	}
       case NODE_FCALL:
       case NODE_VCALL:{		/* VCALL: variable or call */
 	/*
diff --git a/defs/id.def b/defs/id.def
index 57c0ae9f14..53ed3775ad 100644
--- a/defs/id.def
+++ b/defs/id.def
@@ -1,5 +1,6 @@
 # -*- mode: ruby; coding: us-ascii -*-
 firstline, predefined = __LINE__+1, %[\
+  freeze
   inspect
   intern
   object_id
diff --git a/insns.def b/insns.def
index 6075d98db2..63a36b3979 100644
--- a/insns.def
+++ b/insns.def
@@ -999,6 +999,20 @@ send
     CALL_METHOD(ci);
 }
 
+DEFINE_INSN
+opt_str_freeze
+(VALUE str)
+()
+(VALUE val)
+{
+    if (BASIC_OP_UNREDEFINED_P(BOP_FREEZE, STRING_REDEFINED_OP_FLAG)) {
+	val = str;
+    }
+    else {
+	val = rb_funcall(rb_str_resurrect(str), idFreeze, 0);
+    }
+}
+
 /**
   @c optimize
   @e Invoke method without block, splat
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);
diff --git a/vm.c b/vm.c
index 7d07b66a32..77a77ea97b 100644
--- a/vm.c
+++ b/vm.c
@@ -1082,6 +1082,7 @@ vm_init_redefined_flag(void)
     OP(EmptyP, EMPTY_P), (C(Array), C(String), C(Hash));
     OP(Succ, SUCC), (C(Fixnum), C(String), C(Time));
     OP(EqTilde, MATCH), (C(Regexp), C(String));
+    OP(Freeze, FREEZE), (C(String));
 #undef C
 #undef OP
 }
diff --git a/vm_insnhelper.h b/vm_insnhelper.h
index 8870fca47c..c637407cbc 100644
--- a/vm_insnhelper.h
+++ b/vm_insnhelper.h
@@ -56,6 +56,7 @@ enum {
   BOP_NOT,
   BOP_NEQ,
   BOP_MATCH,
+  BOP_FREEZE,
 
   BOP_LAST_
 };