libc/src/termios/linux/kernel_termios.h

   1 //===-- Definition of kernel's version of struct termios --------*- 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_TERMIOS_LINUX_KERNEL_TERMIOS_H
  10 #define LLVM_LIBC_SRC_TERMIOS_LINUX_KERNEL_TERMIOS_H
  11
  12 #include "src/__support/macros/config.h"
  13 #include <stddef.h>
  14 #include <termios.h>
  15
  16 namespace LIBC_NAMESPACE_DECL {
  17
  18 // The kernel's struct termios is different from the libc's struct termios. The
  19 // kernel's syscalls expect the size and layout of its definition of struct
  20 // termios. So, we define a flavor of struct termios which matches that of the
  21 // kernel so that we can translate between the libc version and the kernel
  22 // version when passing struct termios objects to syscalls.
  23
  24 // NOTE: The definitions here are generic definitions valid for most target
  25 // architectures including x86_64 and aarch64. Definitions on some architectures
  26 // deviate from these generic definitions. Adjustments have to be made for those
  27 // architectures.
  28
  29 constexpr size_t KERNEL_NCCS = 19;
  30
  31 struct kernel_termios {
  32   tcflag_t c_iflag;
  33   tcflag_t c_oflag;
  34   tcflag_t c_cflag;
  35   tcflag_t c_lflag;
  36   cc_t c_line;
  37   cc_t c_cc[KERNEL_NCCS];
  38 };
  39
  40 } // namespace LIBC_NAMESPACE_DECL
  41
  42 #endif // LLVM_LIBC_SRC_TERMIOS_LINUX_KERNEL_TERMIOS_H