[ruby-dev:32622] binding of caller

なかだです。

Binding.of_callerとかBinding#callerとかbindingのオプショナル引数
とかを実装してみました。


Index: proc.c
===================================================================
--- proc.c	(revision 14286)
+++ proc.c	(working copy)
@@ -174,18 +174,93 @@ binding_clone(VALUE self)
 }
 
+static int
+caller_level(int argc, VALUE *argv, int minimum)
+{
+    VALUE v;
+    int level;
+
+    if (!argc) return minimum;
+    rb_scan_args(argc, argv, "1", &v);
+    level = NUM2INT(v);
+    if (level < 0) {
+	rb_raise(rb_eArgError, "negative caller level: %d", level);
+    }
+    if (level < minimum) {
+	rb_raise(rb_eArgError, "caller level out of range: %d", level);
+    }
+    return level;
+}
+
+VALUE
+rb_binding_caller(VALUE self, int level)
+{
+    rb_thread_t *th = GET_THREAD();
+    rb_control_frame_t *cfp;
+    rb_binding_t *bind;
+    VALUE envval, bindval;
+
+    GetBindingPtr(self, bind);
+    envval = bind->env;
+    cfp = bind->cfp;
+    do {
+	cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);
+	cfp = vm_get_ruby_level_cfp(th, cfp);
+	if (!cfp) return Qnil;
+    } while (level-- > 0);
+
+    bindval = binding_alloc(rb_obj_class(self));
+    GetBindingPtr(bindval, bind);
+    bind->env = vm_make_env_object(th, cfp);
+    bind->cref_stack = vm_get_cref(th, cfp->iseq, cfp);
+    bind->cfp = cfp;
+    return bindval;
+}
+
+static VALUE
+binding_caller(int argc, VALUE *argv, VALUE self)
+{
+    return rb_binding_caller(self, caller_level(argc, argv, 1));
+}
+
 VALUE
 rb_binding_new(void)
 {
+    return rb_binding_at(0);
+}
+
+static VALUE
+binding_at(VALUE klass, int level)
+{
     rb_thread_t *th = GET_THREAD();
-    rb_control_frame_t *cfp = vm_get_ruby_level_cfp(th, th->cfp);
-    VALUE bindval = binding_alloc(rb_cBinding);
+    rb_control_frame_t *cfp = th->cfp;
+    VALUE bindval;
     rb_binding_t *bind;
 
+    for (;;) {
+	cfp = vm_get_ruby_level_cfp(th, cfp);
+	if (!cfp) return Qnil;
+	if (level-- <= 0) break;
+	cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);
+    }
+    bindval = binding_alloc(klass);
     GetBindingPtr(bindval, bind);
     bind->env = vm_make_env_object(th, cfp);
-    bind->cref_stack = ruby_cref();
+    bind->cref_stack = vm_get_cref(th, cfp->iseq, cfp);
+    bind->cfp = cfp;
     return bindval;
 }
 
+VALUE
+rb_binding_at(int level)
+{
+    return binding_at(rb_cBinding, level);
+}
+
+static VALUE
+rb_binding_of_caller(int argc, VALUE *argv, VALUE klass)
+{
+    return binding_at(klass, caller_level(argc, argv, 1));
+}
+
 /*
  *  call-seq:
@@ -205,7 +280,7 @@ rb_binding_new(void)
 
 static VALUE
-rb_f_binding(VALUE self)
+rb_f_binding(int argc, VALUE *argv, VALUE self)
 {
-    return rb_binding_new();
+    return rb_binding_at(caller_level(argc, argv, 0));
 }
 
@@ -1604,5 +1679,7 @@ Init_Binding(void)
     rb_define_method(rb_cBinding, "dup", binding_dup, 0);
     rb_define_method(rb_cBinding, "eval", bind_eval, -1);
-    rb_define_global_function("binding", rb_f_binding, 0);
+    rb_define_method(rb_cBinding, "caller", binding_caller, -1);
+    rb_define_singleton_method(rb_cBinding, "of_caller", rb_binding_of_caller, -1);
+    rb_define_global_function("binding", rb_f_binding, -1);
 }
 
Index: vm_core.h
===================================================================
--- vm_core.h	(revision 14286)
+++ vm_core.h	(working copy)
@@ -509,4 +509,5 @@ typedef struct {
     VALUE env;
     NODE *cref_stack;
+    rb_control_frame_t *cfp;
 } rb_binding_t;
 
Index: include/ruby/intern.h
===================================================================
--- include/ruby/intern.h	(revision 14286)
+++ include/ruby/intern.h	(working copy)
@@ -254,4 +254,6 @@ VALUE rb_proc_call(VALUE, VALUE);
 int rb_proc_arity(VALUE);
 VALUE rb_binding_new(void);
+VALUE rb_binding_at(int);
+VALUE rb_binding_caller(VALUE, int);
 VALUE rb_obj_method(VALUE, VALUE);
 VALUE rb_method_call(int, VALUE*, VALUE);


-- 
--- 僕の前にBugはない。
--- 僕の後ろにBugはできる。
    中田 伸悦