ladybird/Kernel/Syscalls/waitid.cpp
Lenny Maiorani e6f907a155 AK: Simplify constructors and conversions from nullptr_t
Problem:
- Many constructors are defined as `{}` rather than using the ` =
  default` compiler-provided constructor.
- Some types provide an implicit conversion operator from `nullptr_t`
  instead of requiring the caller to default construct. This violates
  the C++ Core Guidelines suggestion to declare single-argument
  constructors explicit
  (https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#c46-by-default-declare-single-argument-constructors-explicit).

Solution:
- Change default constructors to use the compiler-provided default
  constructor.
- Remove implicit conversion operators from `nullptr_t` and change
  usage to enforce type consistency without conversion.
2021-01-12 09:11:45 +01:00

72 lines
2.6 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <Kernel/Process.h>
//#define PROCESS_DEBUG
namespace Kernel {
KResultOr<siginfo_t> Process::do_waitid(idtype_t idtype, int id, int options)
{
switch (idtype) {
case P_ALL:
case P_PID:
case P_PGID:
break;
default:
return KResult(-EINVAL);
}
KResultOr<siginfo_t> result = KResult(KSuccess);
if (Thread::current()->block<Thread::WaitBlocker>({}, options, idtype, id, result).was_interrupted())
return KResult(-EINTR);
ASSERT(!result.is_error() || (options & WNOHANG) || result.error() != KSuccess);
return result;
}
pid_t Process::sys$waitid(Userspace<const Syscall::SC_waitid_params*> user_params)
{
REQUIRE_PROMISE(proc);
Syscall::SC_waitid_params params;
if (!copy_from_user(&params, user_params))
return -EFAULT;
#ifdef PROCESS_DEBUG
dbg() << "sys$waitid(" << params.idtype << ", " << params.id << ", " << params.infop << ", " << params.options << ")";
#endif
auto siginfo_or_error = do_waitid(static_cast<idtype_t>(params.idtype), params.id, params.options);
if (siginfo_or_error.is_error())
return siginfo_or_error.error();
if (!copy_to_user(params.infop, &siginfo_or_error.value()))
return -EFAULT;
return 0;
}
}