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rhbz#908674: Adapt rtl::Allocator::construct to C++11

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...otherwise, at least with some --with-system-boost versions and C++11
compilers, like with Fedora's boost-1.50.0-4.fc18.x86_64 and
gcc-c++-4.7.2-8.fc18.x86_64, using this to copy-construct an instance of
boost::unordered::detail::ptr_node<std::pair<rtl::OUString,Bootstrap_Impl*>> in
the call to p_bootstrap_map->insert(...) in rtl_bootstrap_args_open
(sal/rtl/source/bootstrap.cxx) would memcopy the ptr_node and fail to call
rtl_uString_acquire, leading to memory corruption later on when
rtl_uString_release is called one time too often.

It is not entirely clear to me whether this is a shortcoming of the given Boost
version, but this patch solves the problem and brings rtl::Allocator::construct
in line with the (changed) Allocator requirements of C++11 anyway.

The problem potentially lurks with every use of rtl::Allocator, but only showed
now begining with LO 4.0 where e5111574fd904b38a3980ca4ea3d21cfcb22dea6 "Revert
'sb140: sb140: #i116981# clean up memory upon exit'" re-introduced code into
rtl_bootstrap_args_open that inserts into a boost::unordered_map that uses
rtl::Allocator.

Change-Id: I3be22f59a8eb49d31458480c27f3ce15803c7fd4
This commit is contained in:
Stephan Bergmann 2013-02-14 15:21:46 +01:00
parent bc96a84370
commit c91d353872
3 changed files with 36 additions and 0 deletions
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1
config_host/config_global.h.in
View File

@ -14,6 +14,7 @@ Any change in this header will cause a rebuild of almost everything.
#undef HAVE_CXX11_DELETE
#undef HAVE_CXX11_OVERRIDE
#undef HAVE_CXX11_PERFECT_FORWARDING
#undef HAVE_GCC_BUILTIN_ATOMIC
#undef HAVE_SFINAE_ANONYMOUS_BROKEN
#undef HAVE_THREADSAFE_STATICS

23
configure.ac
View File

@ -5785,6 +5785,29 @@ else
AC_MSG_RESULT([no (C++11 disabled)])
fi
dnl ===================================================================
dnl Check for C++11 perfect forwarding support
dnl ===================================================================
HAVE_CXX11_PERFECT_FORWARDING=
AC_MSG_CHECKING([whether $CXX supports C++11 perfect forwarding])
save_CXXFLAGS=$CXXFLAGS
CXXFLAGS="$CXXFLAGS $CXXFLAGS_CXX11"
AC_LANG_PUSH([C++])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <utility>
template<typename T, typename... Args> T * f(Args &&... v) {
return new T(std::forward<Args>(v)...);
}
]], [[
f<int>(0);
]])], [perfect_forwarding=yes], [perfect_forwarding=no])
AC_LANG_POP([C++])
CXXFLAGS=$save_CXXFLAGS
AC_MSG_RESULT([$perfect_forwarding])
if test "$perfect_forwarding" = yes; then
AC_DEFINE([HAVE_CXX11_PERFECT_FORWARDING])
fi
dnl ===================================================================
dnl system stl sanity tests
dnl ===================================================================

12
sal/inc/rtl/allocator.hxx
View File

@ -23,6 +23,10 @@
#include "rtl/alloc.h"
#include <cstddef>
#if defined LIBO_INTERNAL_ONLY
#include "config_global.h"
#endif
/// @cond INTERNAL
//######################################################
@ -125,10 +129,18 @@ public:
}
//-----------------------------------------
#if defined HAVE_CXX11_PERFECT_FORWARDING
template< typename... Args >
void construct (pointer p, Args &&... value)
{
new ((void*)p)T(std::forward< Args >(value)...);
}
#else
void construct (pointer p, const T& value)
{
new ((void*)p)T(value);
}
#endif
//-----------------------------------------
void destroy (pointer p)