g++-4.7.0 warns about non-virtual destructor when -Wall

[david x callaway <dxc@…>]

// output lines are pre-broken because I didn't know what your
// formatter would do to it.
//
// sure, I could turn the warning off, but I don't want to turn it off for
// production code and I don't want to use a bunch of pragmas and
// conditional garbage to make gcc and msvc happy.
//
//    thx
//    dxc
//
// compile the test code like this (use your own appropriate paths):
//     /opt/gcc-4.7.0/bin/g++ -m64  -Wall -I ../boost t.cpp
//        ~/boost/boost/osx/lib/libboost_thread-xgcc42-mt-s-1_49.a
// fails, see errors included below, after the test code.

// boost-1.49.0, test code compiled  on os/x 10.7.3
// we normally compile -Werror -Wall -Wextra, so to us this failure is
// a serious problem.

// gcc-4.6.3 built the same way (using the same build script to build
// gcc) compiles this with no warnings.
// if no -Wall gcc-4.7.0 also compiles it with no warnings.
// gcc-4.7.0 output with -Wall is shown after the test code

// --- cut ---
#include "boost/thread.hpp"
int main(int /* argc */, const char** /* argv */)
{
    return 0;
}
// --- cut ---

//-----------------------------------------------------

// gcc -v output:
// Using built-in specs.
// COLLECT_GCC=/opt/gcc-4.7.0/bin/gcc
// COLLECT_LTO_WRAPPER=/opt/gcc-4.7.0/libexec/gcc/x86_64-apple-darwin11.3.0/4.7.0/lto-wrapper
// Target: x86_64-apple-darwin11.3.0
// Configured with: ../gcc-4.7.0/configure --prefix=/opt/gcc-4.7.0
//     --enable-languages=c,c++
//     --disable-nls --enable-__cxa_atexit --enable-shared --enable-threads
//     --with-gmp=/opt/gcc-4.7.0 --with-mpc=/opt/gcc-4.7.0 --with-mpfr=/opt/gcc-4.7.0
// Thread model: posix
// gcc version 4.7.0 (GCC)

//-----------------------------------------------------

// compiler output from g++-4.7.0:

// In file included from ../boost/boost/smart_ptr/shared_ptr.hpp:30:0,
//                  from ../boost/boost/shared_ptr.hpp:17,
//                  from ../boost/boost/thread/pthread/thread_data.hpp:10,
//                  from ../boost/boost/thread/thread.hpp:17,
//                  from ../boost/boost/thread.hpp:13,
//                  from t.cpp:24:
// ../boost/boost/checked_delete.hpp: In instantiation of 'void boost::checked_delete(T*) [with T =
// boost::error_info<boost::tag_original_exception_type, const std::type_info*>]':
// ../boost/boost/smart_ptr/detail/shared_count.hpp:95:13:   required from
// 'boost::detail::shared_count::shared_count(Y*) [with Y =
// boost::error_info<boost::tag_original_exception_type, const std::type_info*>]'
// ../boost/boost/smart_ptr/shared_ptr.hpp:183:50:   required from
// 'boost::shared_ptr<T>::shared_ptr(Y*) [with Y =
// boost::error_info<boost::tag_original_exception_type, const std::type_info*>; T =
// boost::error_info<boost::tag_original_exception_type, const std::type_info*>]'
// ../boost/boost/exception/info.hpp:171:69:   required from 'const E&
// boost::exception_detail::set_info(const E&, const boost::error_info<Tag, T>&) [with E =
// boost::unknown_exception; Tag = boost::tag_original_exception_type; T = const std::type_info*]'
// ../boost/boost/exception/info.hpp:192:46:   required from 'typename
// boost::enable_if<boost::exception_detail::derives_boost_exception<E>, const E&>::type
// boost::operator<<(const E&, const boost::error_info<Tag, T>&) [with E = boost::unknown_exception;
// Tag = boost::tag_original_exception_type; T = const std::type_info*; typename
// boost::enable_if<boost::exception_detail::derives_boost_exception<E>, const E&>::type = const
// boost::unknown_exception&]'
// ../boost/boost/exception/detail/exception_ptr.hpp:182:13:   required from 'void
// boost::unknown_exception::add_original_type(const E&) [with E = std::exception]'
// ../boost/boost/exception/detail/exception_ptr.hpp:161:32:   required from here
// ../boost/boost/checked_delete.hpp:34:5: warning: deleting object of polymorphic class type
// 'boost::error_info<boost::tag_original_exception_type, const std::type_info*>' which has non-virtual
// destructor might cause undefined behaviour [-Wdelete-non-virtual-dtor]

[david x callaway <dxc@…>]

this has the same root cause as #6824 but a different compiler.

[anonymous]

this issue is fixed in 1.50.

[viboes]

Duplicate #6824.