From: Tobias Peters <tpeters@...>
Date: 2002-12-20T21:01:19+09:00
Subject: Re: msys w/ FXRuby

On Fri, 20 Dec 2002, Norman Su wrote in comp.lang.ruby:
> g++ -DIMPORT -DNT -D__NO_ISOCEXT -g -O2  -DWIN32
[...]
> opengl_wrap.cpp:724: `alloca' undeclared (first use this function)
> make: *** [opengl_wrap.o] Error 1
> 

> <sigh> Any ideas?

I ran into a similar problem when I compiled a ruby extension written in 
C++ that included the <cmath> header file.

see my MinGW bug report here: 
http://sourceforge.net/tracker/index.php?func=detail&aid=645866&group_id=2435&atid=102435

Erasing the "-D__NO_ISOCEXT" from the command line helped. Hope it works 
for you, too.

Any idea why this Preprocessor symbol was added for MinGW compilation in 
the first place?

  T