libc/src/errno/libc_errno.h

   1 //===-- Implementation header for errno -------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIBC_SRC_ERRNO_LIBC_ERRNO_H
  10 #define LLVM_LIBC_SRC_ERRNO_LIBC_ERRNO_H
  11
  12 #include "src/__support/macros/attributes.h"
  13 #include "src/__support/macros/properties/architectures.h"
  14
  15 #include <errno.h>
  16
  17 // If we are targeting the GPU we currently don't support 'errno'. We simply
  18 // consume it.
  19 #ifdef LIBC_TARGET_ARCH_IS_GPU
  20 namespace LIBC_NAMESPACE {
  21 struct ErrnoConsumer {
  22   void operator=(int) {}
  23 };
  24 } // namespace LIBC_NAMESPACE
  25 #endif
  26
  27 // All of the libc runtime and test code should use the "libc_errno" macro. They
  28 // should not refer to the "errno" macro directly.
  29 #ifdef LIBC_COPT_PUBLIC_PACKAGING
  30 #ifdef LIBC_TARGET_ARCH_IS_GPU
  31 extern "C" LIBC_NAMESPACE::ErrnoConsumer __llvmlibc_errno;
  32 #define libc_errno __llvmlibc_errno
  33 #else
  34 // This macro will resolve to errno from the errno.h file included above. Under
  35 // full build, this will be LLVM libc's errno. In overlay build, it will be
  36 // system libc's errno.
  37 #define libc_errno errno
  38 #endif
  39 #else
  40 namespace LIBC_NAMESPACE {
  41
  42 // TODO: On the GPU build this will be mapped to a single global value. We need
  43 // to ensure that tests are not run with multiple threads that depend on errno
  44 // until we have true 'thread_local' support on the GPU.
  45 extern "C" LIBC_THREAD_LOCAL int __llvmlibc_internal_errno;
  46
  47 // TODO: After all of libc/src and libc/test are switched over to use
  48 // libc_errno, this header file will be "shipped" via an add_entrypoint_object
  49 // target. At which point libc_errno, should point to __llvmlibc_internal_errno
  50 // if LIBC_COPT_PUBLIC_PACKAGING is not defined.
  51 #define libc_errno LIBC_NAMESPACE::__llvmlibc_internal_errno
  52
  53 } // namespace LIBC_NAMESPACE
  54 #endif
  55
  56 #endif // LLVM_LIBC_SRC_ERRNO_LIBC_ERRNO_H