> I propose a new method, #location than those two new methods.
...
> --
> Nobu Nakada

Interestingly, there already was an rb_proc_location method in 1.9
[just no Proc#location nor Method#location nor Binding#location].

Anyway, here's Nobu Nakada's patch with the method name changed to
source_location [should work against SVN head].

Note also the recent creation of
Feature #578: add method to disassemble Proc objects

Thanks for your help.  I know I'm annoying with this :)
-=R

Index: proc.c
===================================================================
--- proc.c	(revision 19438)
+++ proc.c	(working copy)
@@ -509,11 +509,11 @@
 {
     rb_proc_t *proc;
     rb_block_t *blockptr = 0;
+    rb_iseq_t *iseq;
     GetProcPtr(procval, proc);
+    iseq = proc->block.iseq;
+    if (BUILTIN_TYPE(iseq) == T_NODE || iseq->arg_block != -1) {

-    if (BUILTIN_TYPE(proc->block.iseq) == T_NODE ||
-	proc->block.iseq->arg_block != -1) {
-
 	if (rb_block_given_p()) {
 	    rb_proc_t *proc;
 	    VALUE procval;
@@ -620,10 +620,9 @@
     return iseq;
 }

-VALUE
-rb_proc_location(VALUE self)
+static VALUE
+iseq_location(rb_iseq_t *iseq)
 {
-    rb_iseq_t *iseq = get_proc_iseq(self);
     VALUE loc[2];

     if (!iseq) return Qnil;
@@ -639,6 +638,20 @@

 /*
  * call-seq:
+ *    prc.source_location  => [String, Fixnum]
+ *
+ * returns the ruby source filename and line number containing this proc
+ * or nil if this proc was not defined in ruby (i.e. native)
+ */
+
+VALUE
+rb_proc_source_location(VALUE self)
+{
+    return iseq_location(get_proc_iseq(self));
+}
+
+/*
+ * call-seq:
  *   prc == other_proc   =>  true or false
  *
  * Return <code>true</code> if <i>prc</i> is the same object as
@@ -1437,7 +1450,40 @@
     return rb_mod_method_arity(CLASS_OF(obj), id);
 }

+static rb_iseq_t *
+get_method_iseq(VALUE method)
+{
+    struct METHOD *data;
+    NODE *body;
+    rb_iseq_t *iseq;
+
+    Data_Get_Struct(method, struct METHOD, data);
+    body = data->body;
+    switch (nd_type(body)) {
+      case RUBY_VM_METHOD_NODE:
+       GetISeqPtr((VALUE)body->nd_body, iseq);
+       if (RUBY_VM_NORMAL_ISEQ_P(iseq)) break;
+      default:
+       return 0;
+    }
+    return iseq;
+}
+
 /*
+ * call-seq:
+ *    meth.source_location  => [String, Fixnum]
+ *
+ * returns the ruby source filename and line number containing this method
+ * or nil if this method was not defined in ruby (i.e. native)
+ */
+
+VALUE
+rb_method_source_location(VALUE method)
+{
+    return iseq_location(get_method_iseq(method));
+}
+
+/*
  *  call-seq:
  *   meth.to_s      =>  string
  *   meth.inspect   =>  string
@@ -1768,6 +1814,7 @@
     rb_define_method(rb_cProc, "lambda?", proc_lambda_p, 0);
     rb_define_method(rb_cProc, "binding", proc_binding, 0);
     rb_define_method(rb_cProc, "curry", proc_curry, -1);
+    rb_define_method(rb_cProc, "source_location", rb_proc_source_location, 0);

     /* Exceptions */
     rb_eLocalJumpError = rb_define_class("LocalJumpError", rb_eStandardError);
@@ -1802,6 +1849,7 @@
     rb_define_method(rb_cMethod, "name", method_name, 0);
     rb_define_method(rb_cMethod, "owner", method_owner, 0);
     rb_define_method(rb_cMethod, "unbind", method_unbind, 0);
+    rb_define_method(rb_cMethod, "source_location",
rb_method_source_location, 0);
     rb_define_method(rb_mKernel, "method", rb_obj_method, 1);
     rb_define_method(rb_mKernel, "public_method", rb_obj_public_method, 1);

@@ -1819,6 +1867,7 @@
     rb_define_method(rb_cUnboundMethod, "name", method_name, 0);
     rb_define_method(rb_cUnboundMethod, "owner", method_owner, 0);
     rb_define_method(rb_cUnboundMethod, "bind", umethod_bind, 1);
+    rb_define_method(rb_cUnboundMethod, "source_location",
rb_method_source_location, 0);

     /* Module#*_method */
     rb_define_method(rb_cModule, "instance_method", rb_mod_instance_method, 1);
Index: thread.c
===================================================================
--- thread.c	(revision 19438)
+++ thread.c	(working copy)
@@ -528,10 +528,10 @@
     }
     GetThreadPtr(thread, th);
     if (th->first_args) {
-	VALUE rb_proc_location(VALUE self);
+	VALUE rb_proc_source_location(VALUE self);
 	VALUE proc = th->first_proc, line, loc;
 	const char *file;
-        if (!proc || !RTEST(loc = rb_proc_location(proc))) {
+        if (!proc || !RTEST(loc = rb_proc_source_location(proc))) {
             rb_raise(rb_eThreadError, "already initialized thread");
         }
 	file = RSTRING_PTR(RARRAY_PTR(loc)[0]);