Bug 210452

Description of problem:

I use g++ 3.4.6 (vanilla GNU version) for everything on FC5 x86_64 because of
the extremely slow linking process with gcc4 (you may remember my other bugzilla
entry on this issue). Yesterday I started chasing down a problem with valgrind
when I stumbled across something unrelated.

When running a simple C++ program using boost::regex, built with g++ 3.4.6,
valgrind complains:

==27465== Conditional jump or move depends on uninitialised value(s)
==27465==    at 0x387708031D: std::collate<char>::do_transform(char const*, char
const*) const (in /usr/lib64/libstdc++.so.6.0.8)
==27465==    by 0x4A8C78A:
boost::re_detail::cpp_regex_traits_implementation<char>::transform(char const*,
char const*) const (in /usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27465==    by 0x4A8C95D: unsigned
boost::re_detail::find_sort_syntax<boost::re_detail::cpp_regex_traits_implementation<char>,
char>(boost::re_detail::cpp_regex_traits_implementation<char> const*, char*) (in
/usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27465==    by 0x4A90681:
boost::re_detail::cpp_regex_traits_implementation<char>::init() (in
/usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27465==    by 0x4A933F0:
boost::object_cache<boost::re_detail::cpp_regex_traits_base<char>,
boost::re_detail::cpp_regex_traits_implementation<char>
>::do_get(boost::re_detail::cpp_regex_traits_base<char> const&, unsigned long)
(in /usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27465==    by 0x4A93B2E:
boost::object_cache<boost::re_detail::cpp_regex_traits_base<char>,
boost::re_detail::cpp_regex_traits_implementation<char>
>::get(boost::re_detail::cpp_regex_traits_base<char> const&, unsigned long) (in
/usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27465==    by 0x4A94D08: boost::basic_regex<char, boost::regex_traits<char,
boost::cpp_regex_traits<char> > >::do_assign(char const*, char const*, unsigned)
(in /usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27465==    by 0x400BB2: boost::basic_regex<char, boost::regex_traits<char,
boost::cpp_regex_traits<char> > >::assign(char const*, char const*, unsigned)
(in /home/sr/val/a.out)
==27465==    by 0x400B54: boost::basic_regex<char, boost::regex_traits<char,
boost::cpp_regex_traits<char> > >::assign(char const*, unsigned) (in
/home/sr/val/a.out)
==27465==    by 0x4009BD: boost::basic_regex<char, boost::regex_traits<char,
boost::cpp_regex_traits<char> > >::basic_regex(char const*, unsigned) (in
/home/sr/val/a.out)
==27465==    by 0x400942: main (in /home/sr/val/a.out)

The current valgrind generates even more useful output:

==27526== Conditional jump or move depends on uninitialised value(s)
==27526==    at 0x387708031D: std::collate<char>::do_transform(char const*, char
const*) const (basic_string.h:232)
==27526==    by 0x4A8D78A:
boost::re_detail::cpp_regex_traits_implementation<char>::transform(char const*,
char const*) const (in /usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27526==    by 0x4A8D95D: unsigned
boost::re_detail::find_sort_syntax<boost::re_detail::cpp_regex_traits_implementation<char>,
char>(boost::re_detail::cpp_regex_traits_implementation<char> const*, char*) (in
/usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27526==    by 0x4A91681:
boost::re_detail::cpp_regex_traits_implementation<char>::init() (in
/usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27526==    by 0x4A943F0:
boost::object_cache<boost::re_detail::cpp_regex_traits_base<char>,
boost::re_detail::cpp_regex_traits_implementation<char>
>::do_get(boost::re_detail::cpp_regex_traits_base<char> const&, unsigned long)
(in /usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27526==    by 0x4A94B2E:
boost::object_cache<boost::re_detail::cpp_regex_traits_base<char>,
boost::re_detail::cpp_regex_traits_implementation<char>
>::get(boost::re_detail::cpp_regex_traits_base<char> const&, unsigned long) (in
/usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27526==    by 0x4A95D08: boost::basic_regex<char, boost::regex_traits<char,
boost::cpp_regex_traits<char> > >::do_assign(char const*, char const*, unsigned)
(in /usr/lib64/libboost_regex-gcc-mt-1_33_1.so.1.33.1)
==27526==    by 0x400BB2: boost::basic_regex<char, boost::regex_traits<char,
boost::cpp_regex_traits<char> > >::assign(char const*, char const*, unsigned)
(in /home/sr/val/a.out)
==27526==    by 0x400B54: boost::basic_regex<char, boost::regex_traits<char,
boost::cpp_regex_traits<char> > >::assign(char const*, unsigned) (in
/home/sr/val/a.out)
==27526==    by 0x4009BD: boost::basic_regex<char, boost::regex_traits<char,
boost::cpp_regex_traits<char> > >::basic_regex(char const*, unsigned) (in
/home/sr/val/a.out)
==27526==    by 0x400942: main (in /home/sr/val/a.out)

valgrind seems to think that the reference count for some std::string is
uninitialized. I hate to say it, but valgrind is usually right...

Version-Release number of selected component (if applicable):

FC5 current as of today (libstdc++-4.1.1-1.fc5)


How reproducible:

Build gcc 3.4.6 like this:

get *-core-* and *-g++-*, extract, ...
../configure --prefix=/tmp/gcc346 --enable-__cxa_atexit
make bootstrap
make install

/tmp/gcc346/bin/g++ e.cpp -lboost_regex
valgrind ./a.out

The test program e.cpp looks like this:

#include <boost/regex.hpp>

int main()
{
    boost::regex
iso_regex("(\\d{4})-(\\d{2})-(\\d{2})\\s*(\\d{2}):(\\d{2}):(\\d{2})");
    return 0;
}


Actual results:

valgrind complains


Expected results:

no complaints from valgrind

Additional info:

The problem turned up with my custom-compiled boost (compiled with gcc 3.4.6 as
well) but is exactly the same with the one from Fedora (it may be on extras). So
it doesn't matter which compiler was used to build boost, apparently.

The problem disappears when I do LD_LIBRARY_PATH=/tmp/gcc346/lib64. That's why I
labeled it as a binary compatibility issue.