From d27153f038c2f39ed1b7e6ba9dab59f88b8ca245 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Mon, 15 Feb 2021 14:00:36 +0000 Subject: [PATCH] libstdc++: Add missing return and use reserved name The once_flag::_M_activate() function is only ever called immediately after a call to once_flag::_M_passive(), and so in the non-gthreads case it is impossible for _M_passive() to be true in the body of _M_activate(). Add a check for it anyway, to avoid warnings about missing return. Also replace a non-reserved name with a reserved one. libstdc++-v3/ChangeLog: * include/std/mutex (once_flag::_M_activate()): Add explicit return statement for passive case. (once_flag::_M_finish(bool)): Use reserved name for parameter. --- libstdc++-v3/include/std/mutex | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/libstdc++-v3/include/std/mutex b/libstdc++-v3/include/std/mutex index 25e580cf0fc..f96c48e88ec 100644 --- a/libstdc++-v3/include/std/mutex +++ b/libstdc++-v3/include/std/mutex @@ -706,6 +706,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION bool _M_activate(); // Must be called to complete an active execution. + // The argument is true if the active execution was a returning execution, + // false if it was an exceptional execution. void _M_finish(bool __returning) noexcept; // RAII helper to call _M_finish. @@ -742,18 +744,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION inline bool once_flag::_M_activate() { - if (_M_once == _Bits::_Init) + if (_M_once == _Bits::_Init) [[__likely__]] { _M_once = _Bits::_Active; return true; } - else if (!_M_passive()) + else if (_M_passive()) // Caller should have checked this already. + return false; + else __throw_system_error(EDEADLK); } inline void - once_flag::_M_finish(bool returning) noexcept - { _M_once = returning ? _Bits::_Done : _Bits::_Init; } + once_flag::_M_finish(bool __returning) noexcept + { _M_once = __returning ? _Bits::_Done : _Bits::_Init; } #elif defined _GLIBCXX_HAVE_LINUX_FUTEX -- 2.30.2