From: Yusuke ENDOH <mame@...>
Date: 2010-02-13T20:59:40+09:00
Subject: [ruby-core:28167] Re: [Feature #2740] Extend const_missing to pass in 	the nesting

Hi,

2010/2/13 Yehuda Katz <redmine@ruby-lang.org>:
> > 1. It changes the const_missing API, breaking code. It would be nice to
> >    find a way around this.
>
> A simple arity check will get around this issue.

It's ugly.  The core should avoid such a dirty hack when possible.
I also think it would be nice to find another clean API.


> I have attached a patch that makes nesting available in const_missing if the const_missing method has an arity other than 1.

It causes SEGV.


$ ./miniruby -e '
class C
  def self.const_missing(id, nesting)
    p id, nesting
  end
end
C.enum_for(:const_get, :D).next
'
[BUG] Segmentation fault
ruby 1.9.2dev (2010-02-13 trunk 26659) [i686-linux]

-- control frame ----------
c:0005 p:---- s:0009 b:0009 l:000008 d:000008 CFUNC  :nesting
c:0004 p:---- s:0007 b:0007 l:000006 d:000006 CFUNC  :const_get
c:0003 p:---- s:0005 b:0005 l:000004 d:000004 CFUNC  :each
c:0002 p:---- s:0003 b:0003 l:002168 d:000002 IFUNC
c:0001 p:---- s:0001 b:-001 l:000000 d:000000 ------
---------------------------
-- Ruby level backtrace information ----------------------------------------
-e:0:in `each'
-e:0:in `const_get'
-e:0:in `nesting'

-- C level backtrace information -------------------------------------------
./miniruby(rb_vm_bugreport+0xbd) [0x81a5c6d]
./miniruby [0x808e69e]
./miniruby(rb_bug+0x28) [0x808e758]
./miniruby [0x813a6b0]
[0xffffe40c]
./miniruby(rb_vm_cref+0x38) [0x8193d88]
./miniruby [0x8090dc4]
./miniruby [0x819d889]
./miniruby(rb_funcall+0x92) [0x819e142]
./miniruby [0x817d571]
./miniruby [0x80db78c]
./miniruby [0x8191bfd]
./miniruby [0x819d889]
./miniruby [0x81a1c2e]
./miniruby(rb_iterate+0xac) [0x8191dac]
./miniruby(rb_block_call+0x3f) [0x8191f3f]
./miniruby [0x808c0d9]
./miniruby [0x819d889]
./miniruby [0x81a1c2e]
./miniruby(rb_iterate+0xac) [0x8191dac]
./miniruby(rb_block_call+0x3f) [0x8191f3f]
./miniruby [0x808c162]
./miniruby [0x8195d5b]
./miniruby(rb_vm_invoke_proc+0x76) [0x819c816]
./miniruby(rb_fiber_start+0x1d2) [0x81aed52]
./miniruby [0x8091479]
./miniruby(ruby_run_node+0x32) [0x8092c92]
./miniruby(main+0x5a) [0x805a8da]
/lib/i686/cmov/libc.so.6(__libc_start_main+0xe5) [0xb7d89455]
./miniruby [0x805a7e1]

[NOTE]
You may have encountered a bug in the Ruby interpreter or extension libraries.
Bug reports are welcome.
For details: http://www.ruby-lang.org/bugreport.html

Aborted

-- 
Yusuke ENDOH <mame@tsg.ne.jp>