From: Nobuyoshi Nakada <nobu@...>
Date: 2008-02-19T09:48:25+09:00
Subject: Re: Different stacktraces in 1.8 and 1.9

Hi,

At Tue, 19 Feb 2008 04:30:32 +0900,
Vladimir Sizikov wrote in [ruby-core:15589]:
> 1. 1/0
> 
> It was producing nice stack trace in MRI 1.8.6:
>  ZeroDivisionError: divided by 0
>         from (irb):1:in `/'
>         from (irb):1
> 
> In MRI 1.9 the stack trace don't even mention the method name!
> ZeroDivisionError: divided by 0
>         from (irb):1
>         from /opt/ruby1.9/lib/ruby/1.9.0/irb.rb:149:in `block (2
> levels) in eval_input'
>         from /opt/ruby1.9/lib/ruby/1.9.0/irb.rb:262:in `signal_status'
>         from /opt/ruby1.9/lib/ruby/1.9.0/irb.rb:146:in `block in eval_input'

This would be an irb issue.

> If invoked not from irb, but from a script file, the method name still
> is not reported:
> div.rb:1:in `<main>': divided by 0 (ZeroDivisionError).
> 
> MRI 1.8.6 produces better output in such case:
> div.rb:1:in `/': divided by 0 (ZeroDivisionError)
>         from div.rb:1

Agreed it is better.

> 2. raise RuntimeError, "heh"
> 
> In MRI 1.8:
> RuntimeError: heh
>         from (irb):2
> 
> In MRI 1.9, one extra line is reported:
> RuntimeError: heh
>         from (irb):3:in `raise'
>         from (irb):3
> 
> Is it really needed to have the extra line with `raise'?

No.


Index: eval.c
===================================================================
--- eval.c	(revision 15543)
+++ eval.c	(working copy)
@@ -226,7 +226,7 @@ ruby_exec_node(void *n, char *file)
     PUSH_TAG();
     if ((state = EXEC_TAG()) == 0) {
+	VALUE iseq = rb_iseq_new(n, rb_str_new2("<main>"),
+				 rb_str_new2(file), Qfalse, ISEQ_TYPE_TOP);
 	SAVE_ROOT_JMPBUF(th, {
-	    VALUE iseq = rb_iseq_new(n, rb_str_new2("<main>"),
-				     rb_str_new2(file), Qfalse, ISEQ_TYPE_TOP);
 	    th->base_block = 0;
 	    val = rb_iseq_eval(iseq);
@@ -776,5 +776,7 @@ rb_f_raise(int argc, VALUE *argv)
 	}
     }
-    rb_raise_jump(rb_make_exception(argc, argv));
+    err = rb_make_exception(argc, argv);
+    GET_THREAD()->cfp++;
+    rb_raise_jump(err);
     return Qnil;		/* not reached */
 }
Index: insns.def
===================================================================
--- insns.def	(revision 15543)
+++ insns.def	(working copy)
@@ -1514,5 +1514,5 @@ opt_div
 	    long mod;
 	    if (y == 0)
-		rb_num_zerodiv();
+		goto INSN_LABEL(normal_dispatch);
 	    if (y < 0) {
 		if (x < 0)


-- 
Nobu Nakada