Module#prepend

* class.c (rb_prepend_module): prepend module into another module.
* eval.c (rb_mod_prepend): new method Module#prepend.  [Feature #1102]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36234 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 42 insertions, 0 deletions

diff --git a/class.c b/class.c
index daaf401497..fc3b483735 100644
--- a/class.c
+++ b/class.c
@@ -56,6 +56,7 @@ class_alloc(VALUE flags, VALUE klass)
     RCLASS_CONST_TBL(obj) = 0;
     RCLASS_M_TBL(obj) = 0;
     RCLASS_SUPER(obj) = 0;
+    RCLASS_ORIGIN(obj) = (VALUE)obj;
     RCLASS_IV_INDEX_TBL(obj) = 0;
     return (VALUE)obj;
 }
@@ -687,6 +688,8 @@ rb_include_module(VALUE klass, VALUE module)
 		break;
 	    }
 	}
+	if (c == klass)
+	    c = RCLASS_ORIGIN(klass);
 	c = RCLASS_SUPER(c) = include_class_new(module, RCLASS_SUPER(c));
 	if (RMODULE_M_TBL(module) && RMODULE_M_TBL(module)->num_entries)
 	    changed = 1;
@@ -696,6 +699,45 @@ rb_include_module(VALUE klass, VALUE module)
     if (changed) rb_clear_cache();
 }
 
+void
+rb_prepend_module(VALUE klass, VALUE module)
+{
+    VALUE p, c, origin;
+
+    rb_frozen_class_p(klass);
+    if (!OBJ_UNTRUSTED(klass)) {
+	rb_secure(4);
+    }
+
+    Check_Type(module, T_MODULE);
+
+    OBJ_INFECT(klass, module);
+    c = RCLASS_SUPER(klass);
+    if (RCLASS_M_TBL(klass) == RCLASS_M_TBL(module))
+	rb_raise(rb_eArgError, "cyclic include detected");
+    for (p = c; p; p = RCLASS_SUPER(p)) {
+	if (BUILTIN_TYPE(p) == T_ICLASS) {
+	    if (RCLASS_M_TBL(p) == RCLASS_M_TBL(module)) {
+		rb_raise(rb_eArgError, "already prepended module");
+	    }
+	}
+    }
+    origin = RCLASS_ORIGIN(klass);
+    if (origin == klass) {
+	origin = class_alloc(T_ICLASS, rb_cClass);
+	RCLASS_SUPER(origin) = RCLASS_SUPER(klass);
+	RCLASS_SUPER(klass) = origin;
+	RCLASS_ORIGIN(klass) = origin;
+	RCLASS_M_TBL(origin) = RCLASS_M_TBL(klass);
+	RCLASS_M_TBL(klass) = 0;
+	c = origin;
+    }
+    RCLASS_SUPER(klass) = include_class_new(module, c);
+    if (RMODULE_M_TBL(module) && RMODULE_M_TBL(module)->num_entries) {
+	rb_clear_cache_by_class(klass);
+    }
+}
+
 /*
  *  call-seq:
  *     mod.included_modules -> array