libc/src/errno/libc_errno.cpp

   1 //===-- Implementation of errno -------------------------------------------===//
   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 #include "src/__support/macros/attributes.h"
  10 #include "src/__support/macros/properties/architectures.h"
  11
  12 namespace LIBC_NAMESPACE {
  13
  14 #ifdef LIBC_TARGET_ARCH_IS_GPU
  15 struct ErrnoConsumer {
  16   void operator=(int) {}
  17 };
  18 #endif
  19
  20 extern "C" {
  21 #ifdef LIBC_COPT_PUBLIC_PACKAGING
  22 // TODO: Declare __llvmlibc_errno only under LIBC_COPT_PUBLIC_PACKAGING and
  23 // __llvmlibc_internal_errno otherwise.
  24 // In overlay mode, this will be an unused thread local variable as libc_errno
  25 // will resolve to errno from the system libc's errno.h. In full build mode
  26 // however, libc_errno will resolve to this thread local variable via the errno
  27 // macro defined in LLVM libc's public errno.h header file.
  28 // TODO: Use a macro to distinguish full build and overlay build which can be
  29 //       used to exclude __llvmlibc_errno under overlay build.
  30 #ifdef LIBC_TARGET_ARCH_IS_GPU
  31 ErrnoConsumer __llvmlibc_errno;
  32 #else
  33 LIBC_THREAD_LOCAL int __llvmlibc_errno;
  34 #endif // LIBC_TARGET_ARCH_IS_GPU
  35 #else
  36 LIBC_THREAD_LOCAL int __llvmlibc_internal_errno;
  37 #endif
  38 } // extern "C"
  39
  40 } // namespace LIBC_NAMESPACE