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| author | Jonathan Wakely <jwakely@redhat.com> | 2022-04-12 10:35:43 +0100 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2022-04-12 22:38:31 +0100 |
| commit | e48933f00d676658ad065d9691a1b61446745386 (patch) | |
| tree | 960dd4e9efe489dad33e8abf25b4af328ee97b54 /libstdc++-v3/include | |
| parent | 2ce0f5185ba95131b3c538507323d8ecb561a0c2 (diff) | |
| download | gcc-e48933f00d676658ad065d9691a1b61446745386.tar.gz | |
libstdc++: Use nothrow new in std::stacktrace
We can avoid the overhead of handling a bad_alloc exception from
std::allocator<std::stacktrace_entry>::allocate by just calling the
nothrow operator new instead.
libstdc++-v3/ChangeLog:
* include/std/stacktrace (basic_stacktrace::_Impl::_M_allocate):
Use nothrow new instead of try block for std::allocator.
(basic_stacktrace::_Impl::_M_deallocate): Use delete for
std::allocator.
Diffstat (limited to 'libstdc++-v3/include')
| -rw-r--r-- | libstdc++-v3/include/std/stacktrace | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/libstdc++-v3/include/std/stacktrace b/libstdc++-v3/include/std/stacktrace index 5f928f10dee..f36c5a9abef 100644 --- a/libstdc++-v3/include/std/stacktrace +++ b/libstdc++-v3/include/std/stacktrace @@ -30,6 +30,7 @@ #if __cplusplus > 202002L && _GLIBCXX_HAVE_STACKTRACE #include <compare> +#include <new> #include <string> #include <sstream> #include <bits/stl_algobase.h> @@ -589,23 +590,43 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION return std::min(__size_max, __alloc_max); } +#if __has_builtin(__builtin_operator_new) >= 201802L +# define _GLIBCXX_OPERATOR_NEW __builtin_operator_new +# define _GLIBCXX_OPERATOR_DELETE __builtin_operator_delete +#else +# define _GLIBCXX_OPERATOR_NEW ::operator new +# define _GLIBCXX_OPERATOR_DELETE ::operator delete +#endif + // Precondition: _M_frames == nullptr && __n != 0 pointer _M_allocate(allocator_type& __alloc, size_type __n) noexcept { if (__n <= _S_max_size(__alloc)) [[likely]] { - __try + if constexpr (is_same_v<allocator_type, allocator<value_type>>) { - _M_frames = __alloc.allocate(__n); - _M_capacity = __n; - return _M_frames; + __n *= sizeof(value_type); + void* const __p = _GLIBCXX_OPERATOR_NEW (__n, nothrow_t{}); + if (__p == nullptr) [[unlikely]] + return nullptr; + _M_frames = static_cast<pointer>(__p); } - __catch (...) + else { + __try + { + _M_frames = __alloc.allocate(__n); + } + __catch (const std::bad_alloc&) + { + return nullptr; + } } + _M_capacity = __n; + return _M_frames; } - return nullptr;; + return nullptr; } void @@ -613,12 +634,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { if (_M_capacity) { - __alloc.deallocate(_M_frames, _M_capacity); + if constexpr (is_same_v<allocator_type, allocator<value_type>>) + _GLIBCXX_OPERATOR_DELETE (static_cast<void*>(_M_frames), + _M_capacity * sizeof(value_type)); + else + __alloc.deallocate(_M_frames, _M_capacity); _M_frames = nullptr; _M_capacity = 0; } } +#undef _GLIBCXX_OPERATOR_DELETE +#undef _GLIBCXX_OPERATOR_NEW + void _M_destroy() noexcept { |