[Boost-bugs] [Boost C++ Libraries] #2655: pure virtual function called under gcc -O2

Subject: [Boost-bugs] [Boost C++ Libraries] #2655: pure virtual function called under gcc -O2
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-01-14 02:34:07

#2655: pure virtual function called under gcc -O2
---------------------------------------+------------------------------------
 Reporter:  eherbst_at_[hidden]  |       Owner:  eric_niebler
     Type:  Support Requests           |      Status:  new         
Milestone:  Boost 1.38.0               |   Component:  xpressive   
  Version:  Boost 1.37.0               |    Severity:  Problem     
 Keywords:                             |  
---------------------------------------+------------------------------------
 The following code results in a pure virtual function call under gcc-4.3.0
 20080428 (red hat 4.3.0-8) with -O2 but not with -O1. The innermost non-
 error-handling stack frame gdb shows is

 boost::xpressive::detail::end_matcher::match<__gnu_cxx::__normal_iterator<char
 const*, std::string>, boost::xpressive::detail::no_next>

 at boost/xpressive/detail/core/flow_control.hpp:64.

 ---
 #include <string>
 #include <boost/xpressive/xpressive_static.hpp>
 #include <boost/xpressive/regex_algorithms.hpp>
 using std::string;
 namespace xpr = boost::xpressive;

 int main()
 {
         string text = "at";
         xpr::sregex r1 = xpr::as_xpr('a'),
                 r2 = 'b' >> r1,
                 r3 = r2 | r1;
         xpr::regex_replace(text, r3, string(""));
         return 0;
 }
 ---

 The problem goes away if I do any one of these:
 - switch the order of the alternation
 - replace 'r1' in the definition of r3 with  xpr::as_xpr('a')
 - replace 'r2' in the definition of r3 with  ('b' >> r1)
 - match to a string not starting with 'a'

 It does not go away if I do one of these:
 - change the 'b' in r2 to 'a'
 - stick a by_ref() around r1 in the definition of r2

 Any ideas?

 Thank you.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/2655>
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