libc/src/stdlib/exit.cpp

//===-- Implementation of exit --------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "src/stdlib/exit.h"
#include "src/__support/OSUtil/exit.h"
#include "src/__support/common.h"
#include "src/__support/macros/config.h"

namespace LIBC_NAMESPACE_DECL {

extern "C" void __cxa_finalize(void *);

// exit needs to clean up TLS and call associated destructors.
// TODO: Strictly speaking, it is not valid to call exit in overlay mode
//       as we have no way to ensure system libc will call the TLS destructors.
//       We should run exit related tests in hermetic mode but this is currently
//       blocked by https://github.com/llvm/llvm-project/issues/133925.
extern "C" [[gnu::weak]] void __cxa_thread_finalize();

// TODO: use recursive mutex to protect this routine.
[[noreturn]] LLVM_LIBC_FUNCTION(void, exit, (int status)) {
// FIXME: The NVPTX target does not support external weak symbols correctly
//        despite being an ELF platform. Disable pending a future split.
#if !defined(LIBC_TARGET_ARCH_IS_NVPTX)
  if (__cxa_thread_finalize)
    __cxa_thread_finalize();
#endif
  __cxa_finalize(nullptr);
  internal::exit(status);
}

} // namespace LIBC_NAMESPACE_DECL