From 213fd71709e40dbcf601f765e80a56b1c624e4a8 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Fri, 9 Nov 2018 20:14:07 +0000 Subject: [PATCH] PR libstdc++/87787 fix UBsan error in std::vector PR libstdc++/87787 * include/bits/stl_uninitialized.h (__relocate_a_1): Do not call memmove when there's nothing to copy (and pointers could be null). From-SVN: r265984 --- libstdc++-v3/ChangeLog | 6 ++++++ libstdc++-v3/include/bits/stl_uninitialized.h | 3 ++- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 755b2c20a09..2a694d96ebd 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,9 @@ +2018-11-09 Jonathan Wakely + + PR libstdc++/87787 + * include/bits/stl_uninitialized.h (__relocate_a_1): Do not call + memmove when there's nothing to copy (and pointers could be null). + 2018-11-07 Hafiz Abid Qadeer * configure: Regenerated. diff --git a/libstdc++-v3/include/bits/stl_uninitialized.h b/libstdc++-v3/include/bits/stl_uninitialized.h index 94c7e151e29..8839bfdcc90 100644 --- a/libstdc++-v3/include/bits/stl_uninitialized.h +++ b/libstdc++-v3/include/bits/stl_uninitialized.h @@ -904,7 +904,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _Tp* __result, allocator<_Up>& __alloc) { ptrdiff_t __count = __last - __first; - __builtin_memmove(__result, __first, __count * sizeof(_Tp)); + if (__count > 0) + __builtin_memmove(__result, __first, __count * sizeof(_Tp)); return __result + __count; }