diff options
Diffstat (limited to 'sys-devel/gcc/files/gcc-13-PR109703-unreachable.patch')
| -rw-r--r-- | sys-devel/gcc/files/gcc-13-PR109703-unreachable.patch | 54 |
1 files changed, 0 insertions, 54 deletions
diff --git a/sys-devel/gcc/files/gcc-13-PR109703-unreachable.patch b/sys-devel/gcc/files/gcc-13-PR109703-unreachable.patch deleted file mode 100644 index f7c7c9f60a70..000000000000 --- a/sys-devel/gcc/files/gcc-13-PR109703-unreachable.patch +++ /dev/null @@ -1,54 +0,0 @@ -https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109703 - -From d50f2599d7b23bdba05a9102645d082ed9bcb05f Mon Sep 17 00:00:00 2001 -From: Kefu Chai <kefu.chai@scylladb.com> -Date: Mon, 1 May 2023 21:24:26 +0100 -Subject: [PATCH] libstdc++: Set _M_string_length before calling _M_dispose() - [PR109703] - -This always sets _M_string_length in the constructor for ranges of input -iterators, such as stream iterators. - -We copy from the source range to the local buffer, and then repeatedly -reallocate a larger one if necessary. When disposing the old buffer, -_M_is_local() is used to tell if the buffer is the local one or not (and -so must be deallocated). In addition to comparing the buffer address -with the local buffer, _M_is_local() has an optimization hint so that -the compiler knows that for a string using the local buffer, there is an -invariant that _M_string_length <= _S_local_capacity (added for PR109299 -via r13-6915-gbf78b43873b0b7). But we failed to set _M_string_length in -the constructor taking a pair of iterators, so the invariant might not -hold, and __builtin_unreachable() is reached. This causes UBsan errors, -and potentially misoptimization. - -To ensure the invariant holds, _M_string_length is initialized to zero -before doing anything else, so that _M_is_local() doesn't see an -uninitialized value. - -This issue only surfaces when constructing a string with a range of -input iterator, and the uninitialized _M_string_length happens to be -greater than _S_local_capacity, i.e., 15 for the std::string -specialization. - -libstdc++-v3/ChangeLog: - - PR libstdc++/109703 - * include/bits/basic_string.h (basic_string(Iter, Iter, Alloc)): - Initialize _M_string_length. - -Signed-off-by: Kefu Chai <kefu.chai@scylladb.com> -Co-authored-by: Jonathan Wakely <jwakely@redhat.com> -(cherry picked from commit cbf6c7a1d16490a1e63e9a5ce00e9a5c44c4c2f2) ---- a/libstdc++-v3/include/bits/basic_string.h -+++ b/libstdc++-v3/include/bits/basic_string.h -@@ -760,7 +760,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11 - _GLIBCXX20_CONSTEXPR - basic_string(_InputIterator __beg, _InputIterator __end, - const _Alloc& __a = _Alloc()) -- : _M_dataplus(_M_local_data(), __a) -+ : _M_dataplus(_M_local_data(), __a), _M_string_length(0) - { - #if __cplusplus >= 201103L - _M_construct(__beg, __end, std::__iterator_category(__beg)); --- -2.31.1 |