From: "Wolfgang Nádasi-Donner" <ed.odanow@...>
Date: 2009-03-10T04:26:51+09:00
Subject: [ruby-core:22785] Re: [Feature #1256] Add constant TAILRECURSION to let a program recognize if tail recursion optimization is implemented

Nobuyoshi Nakada schrieb:
> Hi,
> 
> At Mon, 9 Mar 2009 02:41:55 +0900,
> Wolfgang N�dasi-Donner wrote in [ruby-core:22748]:
>> Tail recursion optimization is an implementation detail and
>> not a language feature in general. I propose to supply a
>> constant TAILRECURSION, which will be set to "true" if this
>> feature is implemented, otherwise "false".
> 
> RubyVM::InstructionSequence.compile_option[:tailcall_optimization]
> 
Thank you for this information. I saw that it still exists in Ruby 1.9.1-p0.

Yesterday I tried to compile Ruby 1.9.1-p0 with changes named by 
Nobuyoshi Nakada. In vm_opts.h I changed

#define OPT_TAILCALL_OPTIMIZATION    0

to

#define OPT_TAILCALL_OPTIMIZATION    1

Afterwards I rebuilt Ruby, but the stack overflow for both examples I 
posted before are still there.

Should I change additional things in the source?

Wolfgang N�dasi-Donner