From: Rick DeNatale <rick.denatale@...>
Date: 2009-02-20T02:51:03+09:00
Subject: Re: How to do conditional compile for Ruby 1.9 in a C extension?

--0016e645ba52e89c590463492e7e
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

On Thu, Feb 19, 2009 at 12:21 PM, Jason Garber <jg@jasongarber.com> wrote:

> I'm working on updating RedCloth for Ruby 1.9.  Since the output of
> #singleton_methods changed from strings to symbols, I think I need a
> conditional compile.  Here's what I tried:
>
> #if RUBY_VERSION < 0x10900
>  if (rb_ary_includes(rb_funcall(self, rb_intern("singleton_methods"),
> 0), btype)) {
> #else
>  if (rb_ary_includes(rb_funcall(self, rb_intern("singleton_methods"),
> 0), rb_str_intern(btype))) {
> #endif
>

from version.h in Ruby 1.9
define RUBY_VERSION "1.9.2"
#define RUBY_RELEASE_DATE "2009-02-16"
#define RUBY_PATCHLEVEL -1
#define RUBY_BRANCH_NAME "trunk"

#define RUBY_VERSION_MAJOR 1
#define RUBY_VERSION_MINOR 9
#define RUBY_VERSION_TEENY 1
#define RUBY_RELEASE_YEAR 2009
#define RUBY_RELEASE_MONTH 2
#define RUBY_RELEASE_DAY 16

and for Ruby 1.8.6
#define RUBY_VERSION "1.8.6"
#define RUBY_RELEASE_DATE "2007-11-12"
#define RUBY_VERSION_CODE 186
#define RUBY_RELEASE_CODE 20071112
#define RUBY_PATCHLEVEL 5000

#define RUBY_VERSION_MAJOR 1
#define RUBY_VERSION_MINOR 8
#define RUBY_VERSION_TEENY 6
#define RUBY_RELEASE_YEAR 2007
#define RUBY_RELEASE_MONTH 11
#define RUBY_RELEASE_DAY 12


so I think that you want something like

#if RUBY_VERSION < '1.9.0'
   do pre 1.9 stuff
#else
   do 1.9 stuff
#end

Matz is careful to use Ruby version numbers which can be compared using
string comparison.

or

#if RUBY_VERSION_MAJOR = 1 && RUBY_VERSION_MINOR == 9
  do 1.9 stuff
#else
  do 1.8 stuff
#end

or some variant on those.

-- 
Rick DeNatale

Blog: http://talklikeaduck.denhaven2.com/
Twitter: http://twitter.com/RickDeNatale
WWR: http://www.workingwithrails.com/person/9021-rick-denatale
LinkedIn: http://www.linkedin.com/in/rickdenatale

--0016e645ba52e89c590463492e7e--