libgloss/arc/hl/hl_isatty.c

   1 /*
   2  * hl_isatty.c -- provide _isatty().
   3  *
   4  * Copyright (c) 2024 Synopsys Inc.
   5  *
   6  * The authors hereby grant permission to use, copy, modify, distribute,
   7  * and license this software and its documentation for any purpose, provided
   8  * that existing copyright notices are retained in all copies and that this
   9  * notice is included verbatim in any distributions. No written agreement,
  10  * license, or royalty fee is required for any of the authorized uses.
  11  * Modifications to this software may be copyrighted by their authors
  12  * and need not follow the licensing terms described here, provided that
  13  * the new terms are clearly indicated on the first page of each file where
  14  * they apply.
  15  *
  16  */
  17
  18 #include <errno.h>
  19 #include <stdint.h>
  20 #include <unistd.h>
  21
  22 #include "hl_toolchain.h"
  23 #include "hl_api.h"
  24
  25 /* Check if fd is a tty on the host.  Implements HL_SYSCALL_ISATTY.  */
  26 static __always_inline int
  27 _hl_isatty (int fd)
  28 {
  29   int32_t ret;
  30   uint32_t host_errno;
  31   volatile __uncached char *p;
  32
  33   p = _hl_message (HL_SYSCALL_ISATTY, "i:ii",
  34                    (uint32_t) fd,               /* i */
  35                    (uint32_t *) &ret,           /* :i */
  36                    (uint32_t *) &host_errno     /* :i */);
  37
  38   if (p == NULL)
  39     {
  40       errno = ETIMEDOUT;
  41       ret = 0;
  42     }
  43   /* isatty() returns 1 if fd is a terminal;
  44    * otherwise it returns 0 and set errno.
  45    */
  46   else if (ret == 0)
  47     {
  48       errno = host_errno;
  49     }
  50   else
  51     {
  52       ret = 1;
  53     }
  54
  55   _hl_delete ();
  56
  57   return ret;
  58 }
  59
  60 int
  61 _isatty (int fd)
  62 {
  63   return _hl_isatty (fd);
  64 }