Author: vsapsai Date: Wed Apr 25 16:38:41 2018 New Revision: 330885 URL: http://llvm.org/viewvc/llvm-project?rev=330885&view=rev Log: [libcxx] func.wrap.func.con: Unset function before destroying anything
Be defensive against a reentrant std::function::operator=(nullptr_t), in case the held function object has a non-trivial destructor. Destroying the function object in-place can lead to the destructor being called twice. Patch by Duncan P. N. Exon Smith. C++03 support by Volodymyr Sapsai. rdar://problem/32836603 Reviewers: EricWF, mclow.lists Reviewed By: mclow.lists Subscribers: cfe-commits, arphaman Differential Revision: https://reviews.llvm.org/D34331 Added: libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/move_reentrant.pass.cpp libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/nullptr_t_assign_reentrant.pass.cpp Modified: libcxx/trunk/include/__functional_03 libcxx/trunk/include/functional Modified: libcxx/trunk/include/__functional_03 URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__functional_03?rev=330885&r1=330884&r2=330885&view=diff ============================================================================== --- libcxx/trunk/include/__functional_03 (original) +++ libcxx/trunk/include/__functional_03 Wed Apr 25 16:38:41 2018 @@ -600,7 +600,10 @@ template<class _Rp> function<_Rp()>& function<_Rp()>::operator=(const function& __f) { - function(__f).swap(*this); + if (__f) + function(__f).swap(*this); + else + *this = nullptr; return *this; } @@ -608,11 +611,12 @@ template<class _Rp> function<_Rp()>& function<_Rp()>::operator=(nullptr_t) { - if (__f_ == (__base*)&__buf_) - __f_->destroy(); - else if (__f_) - __f_->destroy_deallocate(); + __base* __t = __f_; __f_ = 0; + if (__t == (__base*)&__buf_) + __t->destroy(); + else if (__t) + __t->destroy_deallocate(); return *this; } @@ -876,7 +880,10 @@ template<class _Rp, class _A0> function<_Rp(_A0)>& function<_Rp(_A0)>::operator=(const function& __f) { - function(__f).swap(*this); + if (__f) + function(__f).swap(*this); + else + *this = nullptr; return *this; } @@ -884,11 +891,12 @@ template<class _Rp, class _A0> function<_Rp(_A0)>& function<_Rp(_A0)>::operator=(nullptr_t) { - if (__f_ == (__base*)&__buf_) - __f_->destroy(); - else if (__f_) - __f_->destroy_deallocate(); + __base* __t = __f_; __f_ = 0; + if (__t == (__base*)&__buf_) + __t->destroy(); + else if (__t) + __t->destroy_deallocate(); return *this; } @@ -1152,7 +1160,10 @@ template<class _Rp, class _A0, class _A1 function<_Rp(_A0, _A1)>& function<_Rp(_A0, _A1)>::operator=(const function& __f) { - function(__f).swap(*this); + if (__f) + function(__f).swap(*this); + else + *this = nullptr; return *this; } @@ -1160,11 +1171,12 @@ template<class _Rp, class _A0, class _A1 function<_Rp(_A0, _A1)>& function<_Rp(_A0, _A1)>::operator=(nullptr_t) { - if (__f_ == (__base*)&__buf_) - __f_->destroy(); - else if (__f_) - __f_->destroy_deallocate(); + __base* __t = __f_; __f_ = 0; + if (__t == (__base*)&__buf_) + __t->destroy(); + else if (__t) + __t->destroy_deallocate(); return *this; } @@ -1428,7 +1440,10 @@ template<class _Rp, class _A0, class _A1 function<_Rp(_A0, _A1, _A2)>& function<_Rp(_A0, _A1, _A2)>::operator=(const function& __f) { - function(__f).swap(*this); + if (__f) + function(__f).swap(*this); + else + *this = nullptr; return *this; } @@ -1436,11 +1451,12 @@ template<class _Rp, class _A0, class _A1 function<_Rp(_A0, _A1, _A2)>& function<_Rp(_A0, _A1, _A2)>::operator=(nullptr_t) { - if (__f_ == (__base*)&__buf_) - __f_->destroy(); - else if (__f_) - __f_->destroy_deallocate(); + __base* __t = __f_; __f_ = 0; + if (__t == (__base*)&__buf_) + __t->destroy(); + else if (__t) + __t->destroy_deallocate(); return *this; } Modified: libcxx/trunk/include/functional URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/functional?rev=330885&r1=330884&r2=330885&view=diff ============================================================================== --- libcxx/trunk/include/functional (original) +++ libcxx/trunk/include/functional Wed Apr 25 16:38:41 2018 @@ -1818,11 +1818,7 @@ template<class _Rp, class ..._ArgTypes> function<_Rp(_ArgTypes...)>& function<_Rp(_ArgTypes...)>::operator=(function&& __f) _NOEXCEPT { - if ((void *)__f_ == &__buf_) - __f_->destroy(); - else if (__f_) - __f_->destroy_deallocate(); - __f_ = 0; + *this = nullptr; if (__f.__f_ == 0) __f_ = 0; else if ((void *)__f.__f_ == &__f.__buf_) @@ -1842,11 +1838,12 @@ template<class _Rp, class ..._ArgTypes> function<_Rp(_ArgTypes...)>& function<_Rp(_ArgTypes...)>::operator=(nullptr_t) _NOEXCEPT { - if ((void *)__f_ == &__buf_) - __f_->destroy(); - else if (__f_) - __f_->destroy_deallocate(); + __base* __t = __f_; __f_ = 0; + if ((void *)__t == &__buf_) + __t->destroy(); + else if (__t) + __t->destroy_deallocate(); return *this; } Added: libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/move_reentrant.pass.cpp URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/move_reentrant.pass.cpp?rev=330885&view=auto ============================================================================== --- libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/move_reentrant.pass.cpp (added) +++ libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/move_reentrant.pass.cpp Wed Apr 25 16:38:41 2018 @@ -0,0 +1,46 @@ +//===----------------------------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +// <functional> + +// class function<R(ArgTypes...)> + +// function& operator=(function &&); + +#include <functional> +#include <cassert> + +#include "test_macros.h" + +struct A +{ + static std::function<void()> global; + static bool cancel; + + ~A() { + DoNotOptimize(cancel); + if (cancel) + global = std::function<void()>(nullptr); + } + void operator()() {} +}; + +std::function<void()> A::global; +bool A::cancel = false; + +int main() +{ + A::global = A(); + assert(A::global.target<A>()); + + // Check that we don't recurse in A::~A(). + A::cancel = true; + A::global = std::function<void()>(nullptr); + assert(!A::global.target<A>()); +} Added: libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/nullptr_t_assign_reentrant.pass.cpp URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/nullptr_t_assign_reentrant.pass.cpp?rev=330885&view=auto ============================================================================== --- libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/nullptr_t_assign_reentrant.pass.cpp (added) +++ libcxx/trunk/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/nullptr_t_assign_reentrant.pass.cpp Wed Apr 25 16:38:41 2018 @@ -0,0 +1,46 @@ +//===----------------------------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +// <functional> + +// class function<R(ArgTypes...)> + +// function& operator=(nullptr_t); + +#include <functional> +#include <cassert> + +#include "test_macros.h" + +struct A +{ + static std::function<void()> global; + static bool cancel; + + ~A() { + DoNotOptimize(cancel); + if (cancel) + global = nullptr; + } + void operator()() {} +}; + +std::function<void()> A::global; +bool A::cancel = false; + +int main() +{ + A::global = A(); + assert(A::global.target<A>()); + + // Check that we don't recurse in A::~A(). + A::cancel = true; + A::global = nullptr; + assert(!A::global.target<A>()); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
