Re: c++/6749: [2003-05-12] infinte loop with inheritance of abstract classes

[Wolfgang Bangerth <bangerth@ices.utexas.edu>]

The following reply was made to PR c++/6749; it has been noted by GNATS.

From: Wolfgang Bangerth <bangerth@ices.utexas.edu>
To: gcc-bugs@gcc.gnu.org, <gcc-gnats@gcc.gnu.org>, <rullo.pat@tiscalinet.it>
Cc:  
Subject: Re: c++/6749: [2003-05-12] infinte loop with inheritance of abstract
 classes
Date: Tue, 13 May 2003 19:47:44 -0500 (CDT)

 This is even shorter than Nathanael's testcase:
 --------------------------------
 template <class T> struct inner {};
  
 template <class T> struct parent {
     virtual void f()
       { parent<inner<T> > p; };
 };
  
 template struct parent<int>;
 ---------------------------------
 
 I don't think it's particularly surprising that this puts gcc into a loong 
 loop, since in parent<T> we instantiate parent<inner<T> >, in which we 
 instantiate parent<inner<inner<T> > >, in which... well, we get the 
 picture.
 
 Compiling this indeed takes very long. I didn't check how, long, but what 
 _is_ surprising, that it takes long already with -ftemplate-depth-2, which 
 really shouldn't happen.
 
 Funny testcase...
 
 W.
 
 -------------------------------------------------------------------------
 Wolfgang Bangerth              email:            bangerth@ices.utexas.edu
                                www: http://www.ices.utexas.edu/~bangerth/