sim/common/sim-io.c

/* The common simulator framework for GDB, the GNU Debugger.

   Copyright 2002-2025 Free Software Foundation, Inc.

   Contributed by Andrew Cagney and Red Hat.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* This must come before any other includes.  */
#include "defs.h"

#include <errno.h>
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <stdarg.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>

#undef open

#include "sim-main.h"
#include "sim-io.h"
#include "sim/callback.h"

/* Define the rate at which the simulator should poll the host
   for a quit. */
#ifndef POLL_QUIT_INTERVAL
#define POLL_QUIT_INTERVAL 0x10
#endif

static int poll_quit_count = POLL_QUIT_INTERVAL;

/* See the file include/callbacks.h for a description */


int
sim_io_init (SIM_DESC sd)
{
  return STATE_CALLBACK (sd)->init (STATE_CALLBACK (sd));
}


int
sim_io_shutdown (SIM_DESC sd)
{
  return STATE_CALLBACK (sd)->shutdown (STATE_CALLBACK (sd));
}


int
sim_io_unlink (SIM_DESC sd,
	       const char *f1)
{
  return STATE_CALLBACK (sd)->unlink (STATE_CALLBACK (sd), f1);
}


int64_t
sim_io_time (SIM_DESC sd)
{
  return STATE_CALLBACK (sd)->time (STATE_CALLBACK (sd));
}


int
sim_io_system (SIM_DESC sd, const char *s)
{
  return STATE_CALLBACK (sd)->system (STATE_CALLBACK (sd), s);
}


int
sim_io_rename (SIM_DESC sd,
	       const char *f1,
	       const char *f2)
{
  return STATE_CALLBACK (sd)->rename (STATE_CALLBACK (sd), f1, f2);
}


int
sim_io_write_stdout (SIM_DESC sd,
		     const char *buf,
		     int len)
{
  switch (CURRENT_STDIO) {
  case DO_USE_STDIO:
    return STATE_CALLBACK (sd)->write_stdout (STATE_CALLBACK (sd), buf, len);
    break;
  case DONT_USE_STDIO:
    return STATE_CALLBACK (sd)->write (STATE_CALLBACK (sd), 1, buf, len);
    break;
  default:
    sim_io_error (sd, "sim_io_write_stdout: unaccounted switch\n");
    break;
  }
  return 0;
}


void
sim_io_flush_stdout (SIM_DESC sd)
{
  switch (CURRENT_STDIO) {
  case DO_USE_STDIO:
    STATE_CALLBACK (sd)->flush_stdout (STATE_CALLBACK (sd));
    break;
  case DONT_USE_STDIO:
    break;
  default:
    sim_io_error (sd, "sim_io_flush_stdout: unaccounted switch\n");
    break;
  }
}


int
sim_io_write_stderr (SIM_DESC sd,
		     const char *buf,
		     int len)
{
  switch (CURRENT_STDIO) {
  case DO_USE_STDIO:
    return STATE_CALLBACK (sd)->write_stderr (STATE_CALLBACK (sd), buf, len);
    break;
  case DONT_USE_STDIO:
    return STATE_CALLBACK (sd)->write (STATE_CALLBACK (sd), 2, buf, len);
    break;
  default:
    sim_io_error (sd, "sim_io_write_stderr: unaccounted switch\n");
    break;
  }
  return 0;
}


void
sim_io_flush_stderr (SIM_DESC sd)
{
  switch (CURRENT_STDIO) {
  case DO_USE_STDIO:
    STATE_CALLBACK (sd)->flush_stderr (STATE_CALLBACK (sd));
    break;
  case DONT_USE_STDIO:
    break;
  default:
    sim_io_error (sd, "sim_io_flush_stderr: unaccounted switch\n");
    break;
  }
}


int
sim_io_write (SIM_DESC sd,
	      int fd,
	      const char *buf,
	      int len)
{
  return STATE_CALLBACK (sd)->write (STATE_CALLBACK (sd), fd, buf, len);
}


int
sim_io_read_stdin (SIM_DESC sd,
		   char *buf,
		   int len)
{
  switch (CURRENT_STDIO) {
  case DO_USE_STDIO:
    return STATE_CALLBACK (sd)->read_stdin (STATE_CALLBACK (sd), buf, len);
    break;
  case DONT_USE_STDIO:
    return STATE_CALLBACK (sd)->read (STATE_CALLBACK (sd), 0, buf, len);
    break;
  default:
    sim_io_error (sd, "sim_io_read_stdin: unaccounted switch\n");
    break;
  }
  return 0;
}


int
sim_io_read (SIM_DESC sd, int fd,
	     char *buf,
	     int len)
{
  return STATE_CALLBACK (sd)->read (STATE_CALLBACK (sd), fd, buf, len);
}


int
sim_io_open (SIM_DESC sd,
	     const char *name,
	     int flags)
{
  return STATE_CALLBACK (sd)->open (STATE_CALLBACK (sd), name, flags);
}


int64_t
sim_io_lseek (SIM_DESC sd,
	      int fd,
	      int64_t off,
	      int way)
{
  return STATE_CALLBACK (sd)->lseek (STATE_CALLBACK (sd), fd, off, way);
}


int
sim_io_isatty (SIM_DESC sd,
	       int fd)
{
  return STATE_CALLBACK (sd)->isatty (STATE_CALLBACK (sd), fd);
}


int
sim_io_get_errno (SIM_DESC sd)
{
  return STATE_CALLBACK (sd)->get_errno (STATE_CALLBACK (sd));
}


int
sim_io_close (SIM_DESC sd,
	      int fd)
{
  return STATE_CALLBACK (sd)->close (STATE_CALLBACK (sd), fd);
}


void
sim_io_printf (SIM_DESC sd,
	       const char *fmt,
	       ...)
{
  va_list ap;
  va_start (ap, fmt);
  STATE_CALLBACK (sd)->vprintf_filtered (STATE_CALLBACK (sd), fmt, ap);
  va_end (ap);
}


void
sim_io_vprintf (SIM_DESC sd,
		const char *fmt,
		va_list ap)
{
  STATE_CALLBACK (sd)->vprintf_filtered (STATE_CALLBACK (sd), fmt, ap);
}


void
sim_io_eprintf (SIM_DESC sd,
	       const char *fmt,
	       ...)
{
  va_list ap;
  va_start (ap, fmt);
  STATE_CALLBACK (sd)->evprintf_filtered (STATE_CALLBACK (sd), fmt, ap);
  va_end (ap);
}


void
sim_io_evprintf (SIM_DESC sd,
		 const char *fmt,
		 va_list ap)
{
  STATE_CALLBACK (sd)->evprintf_filtered (STATE_CALLBACK (sd), fmt, ap);
}


void
sim_io_error (SIM_DESC sd,
	      const char *fmt,
	      ...)
{
  if (sd == NULL || STATE_CALLBACK (sd) == NULL) {
    va_list ap;
    va_start (ap, fmt);
    vfprintf (stderr, fmt, ap);
    va_end (ap);
    fprintf (stderr, "\n");
    abort ();
  }
  else {
    va_list ap;
    va_start (ap, fmt);
    STATE_CALLBACK (sd)->evprintf_filtered (STATE_CALLBACK (sd), fmt, ap);
    va_end (ap);
    /* The %s avoids empty printf compiler warnings.  Not ideal, but we want
       error's side-effect where it halts processing.  */
    STATE_CALLBACK (sd)->error (STATE_CALLBACK (sd), "%s", "");
  }
}


void
sim_io_poll_quit (SIM_DESC sd)
{
  if (STATE_CALLBACK (sd)->poll_quit != NULL && poll_quit_count-- < 0)
    {
      poll_quit_count = POLL_QUIT_INTERVAL;
      if (STATE_CALLBACK (sd)->poll_quit (STATE_CALLBACK (sd)))
	sim_stop (sd);
    }
}


/* Based on gdb-4.17/sim/ppc/main.c:sim_io_read_stdin().

   FIXME: Should not be calling fcntl() or grubbing around inside of
   ->fdmap and ->errno.

   FIXME: Some completly new mechanism for handling the general
   problem of asynchronous IO is needed.

   FIXME: This function does not suppress the echoing (ECHO) of input.
   Consequently polled input is always displayed.

   FIXME: This function does not perform uncooked reads.
   Consequently, data will not be read until an EOLN character has
   been entered. A cntrl-d may force the early termination of a line */


int
sim_io_poll_read (SIM_DESC sd,
		  int sim_io_fd,
		  char *buf,
		  int sizeof_buf)
{
#if defined(O_NONBLOCK) && defined(F_GETFL) && defined(F_SETFL)
  int fd = STATE_CALLBACK (sd)->fdmap[sim_io_fd];
  int flags;
  int status;
  int nr_read;
  int result;
  STATE_CALLBACK (sd)->last_errno = 0;
  /* get the old status */
  flags = fcntl (fd, F_GETFL, 0);
  if (flags == -1)
    {
      perror ("sim_io_poll_read");
      return 0;
    }
  /* temp, disable blocking IO */
  status = fcntl (fd, F_SETFL, flags | O_NONBLOCK);
  if (status == -1)
    {
      perror ("sim_io_read_stdin");
      return 0;
    }
  /* try for input */
  nr_read = read (fd, buf, sizeof_buf);
  if (nr_read >= 0)
    {
      /* printf ("<nr-read=%d>\n", nr_read); */
      result = nr_read;
    }
  else
    { /* nr_read < 0 */
      result = -1;
      STATE_CALLBACK (sd)->last_errno = errno;
    }
  /* return to regular vewing */
  status = fcntl (fd, F_SETFL, flags);
  if (status == -1)
    {
      perror ("sim_io_read_stdin");
      /* return 0; */
    }
  return result;
#else
  return sim_io_read (sd, sim_io_fd, buf, sizeof_buf);
#endif
}

int
sim_io_stat (SIM_DESC sd, const char *path, struct stat *buf)
{
  return STATE_CALLBACK (sd)->to_stat (STATE_CALLBACK (sd), path, buf);
}

int
sim_io_fstat (SIM_DESC sd, int fd, struct stat *buf)
{
  return STATE_CALLBACK (sd)->to_fstat (STATE_CALLBACK (sd), fd, buf);
}