commit c22bcfd2f7dc9bb5ad394720f4a612327dc898ba Author: Jonathan Wakely Date: Thu Jul 22 11:57:38 2021 libstdc++: Initialize all subobjects of std::function The std::function::swap member swaps each data member unconditionally, resulting in -Wmaybe-uninitialized warnings for a default constructed object. This happens because the _M_invoker and _M_functor members are only initialized if the function has a target. This change ensures that all subobjects are zero-initialized on construction. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * include/bits/std_function.h (_Function_base): Add default member initializers and define constructor as defaulted. (function::_M_invoker): Add default member initializer. diff --git a/libstdc++-v3/include/bits/std_function.h b/libstdc++-v3/include/bits/std_function.h index 31eba2b822c..c08484465c9 100644 --- a/libstdc++-v3/include/bits/std_function.h +++ b/libstdc++-v3/include/bits/std_function.h @@ -237,7 +237,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { __functor._M_access<_Functor*>() = new _Functor(std::move(__f)); } }; - _Function_base() : _M_manager(nullptr) { } + _Function_base() = default; ~_Function_base() { @@ -247,11 +247,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION bool _M_empty() const { return !_M_manager; } - typedef bool (*_Manager_type)(_Any_data&, const _Any_data&, - _Manager_operation); + using _Manager_type + = bool (*)(_Any_data&, const _Any_data&, _Manager_operation); - _Any_data _M_functor; - _Manager_type _M_manager; + _Any_data _M_functor{}; + _Manager_type _M_manager{}; }; template @@ -261,7 +261,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION class _Function_handler<_Res(_ArgTypes...), _Functor> : public _Function_base::_Base_manager<_Functor> { - typedef _Function_base::_Base_manager<_Functor> _Base; + using _Base = _Function_base::_Base_manager<_Functor>; public: static bool @@ -414,7 +414,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION function(_Functor __f) : _Function_base() { - typedef _Function_handler<_Res(_ArgTypes...), _Functor> _My_handler; + using _My_handler = _Function_handler<_Res(_ArgTypes...), _Functor>; if (_My_handler::_M_not_empty_function(__f)) { @@ -634,8 +634,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION private: using _Invoker_type = _Res (*)(const _Any_data&, _ArgTypes&&...); - _Invoker_type _M_invoker; - }; + _Invoker_type _M_invoker = nullptr; + }; #if __cpp_deduction_guides >= 201606 template