* vm.c (eval_get_cvar_base): destination for class variable access

  is now strictly innermost surrounding class or module.  warned
  if accessed from toplevel.

* variable.c (rb_cvar_get): new class variable look-up scheme:
  1) look up in the class.  2) if the class is singleton attached
  to a class (i.e. metaclass) then start look up in the attached
  class and its ancestors. 3) otherwise, look-up in ancestors of
  the class.

* eval.c (cvar_cbase): destination for class variable access is
  the class/module that holds the method, or cbase outside of
  methods.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@11613 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 52 insertions, 23 deletions

diff --git a/ChangeLog b/ChangeLog
index 0df175375c..ebbfa1ad9d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -12,6 +12,22 @@ Fri Feb  2 18:27:54 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 	* eval.c: remove duplicated global variables rb_cProc and
 	  rb_cBinding.  [ruby-dev:30242]
 
+Thu Feb  1 20:53:32 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* vm.c (eval_get_cvar_base): destination for class variable access
+	  is now strictly innermost surrounding class or module.  warned
+	  if accessed from toplevel.
+
+	* variable.c (rb_cvar_get): new class variable look-up scheme:
+	  1) look up in the class.  2) if the class is singleton attached
+	  to a class (i.e. metaclass) then start look up in the attached
+	  class and its ancestors. 3) otherwise, look-up in ancestors of
+	  the class.
+
+	* eval.c (cvar_cbase): destination for class variable access is
+	  the class/module that holds the method, or cbase outside of
+	  methods.
+
 Thu Feb  1 20:31:41 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* variable.c (rb_cvar_set): remove warn argument.
diff --git a/variable.c b/variable.c
index fea78232ed..be94d4314e 100644
--- a/variable.c
+++ b/variable.c
@@ -1570,26 +1570,50 @@ rb_cvar_set(VALUE klass, ID id, VALUE val)
     mod_av_set(klass, id, val, Qfalse);
 }
 
+#define CVAR_LOOKUP(v,r) do {\
+    if (RCLASS(klass)->iv_tbl && st_lookup(RCLASS(klass)->iv_tbl,id,(v))) {\
+	return (r);\
+    }\
+    if (FL_TEST(klass, FL_SINGLETON) ) {\
+	VALUE obj = rb_iv_get(klass, "__attached__");\
+	switch (TYPE(obj)) {\
+	  case T_MODULE:\
+	  case T_CLASS:\
+	    klass = obj;\
+	    break;\
+	  default:\
+	    klass = RCLASS(klass)->super;\
+	    break;\
+	}\
+    }\
+    else {\
+	klass = RCLASS(klass)->super;\
+    }\
+    while (klass) {\
+	if (RCLASS(klass)->iv_tbl && st_lookup(RCLASS(klass)->iv_tbl,id,(v))) {\
+	    return (r);\
+	}\
+	klass = RCLASS(klass)->super;\
+    }\
+} while(0)
+
 VALUE
 rb_cvar_get(VALUE klass, ID id)
 {
-    VALUE value;
-
-    if (RCLASS(klass)->iv_tbl && st_lookup(RCLASS(klass)->iv_tbl,id,&value)) {
-	return value;
-    }
+    VALUE value, tmp;
 
+    tmp = klass;
+    CVAR_LOOKUP(&value, value);
     rb_name_error(id,"uninitialized class variable %s in %s",
-		  rb_id2name(id), rb_class2name(klass));
+		  rb_id2name(id), rb_class2name(tmp));
     return Qnil;		/* not reached */
 }
 
 VALUE
 rb_cvar_defined(VALUE klass, ID id)
 {
-    if (RCLASS(klass)->iv_tbl && st_lookup(RCLASS(klass)->iv_tbl,id,0)) {
-	return Qtrue;
-    }
+    if (!klass) return Qfalse;
+    CVAR_LOOKUP(0,Qtrue);
     return Qfalse;
 }
 
diff --git a/vm.c b/vm.c
index 8898cfb516..cdf61509e6 100644
--- a/vm.c
+++ b/vm.c
@@ -1141,22 +1141,11 @@ eval_get_cvar_base(yarv_thread_t *th, yarv_iseq_t *iseq)
     NODE *cref = get_cref(iseq, th->cfp->lfp);
     VALUE klass = Qnil;
 
-    while (cref) {
+    if (cref) {
 	klass = cref->nd_clss;
-	cref = cref->nd_next;
-
-	if (cref == 0) {
-	    continue;
+	if (!cref->nd_next) {
+	    rb_warn("class variable access from toplevel");
 	}
-
-	if (NIL_P(klass) || FL_TEST(klass, FL_SINGLETON)) {
-	    if (cref->nd_next == 0) {
-		rb_warn
-		    ("class variable access from toplevel singleton method");
-	    }
-	    continue;
-	}
-	break;
     }
     if (NIL_P(klass)) {
 	rb_raise(rb_eTypeError, "no class variables available");