Assume termios is available, remove support for termio and sgtty

This commit garbage collects the termio and sgtty support.

GDB's terminal handling code still has support for the old termio and
sgtty interfaces in addition to termios.  However, I think it's pretty
safe to assume that for a long, long time, Unix-like systems provide
termios.  GNU/Linux, Solaris, Cygwin, AIX, DJGPP, macOS and the BSDs
all have had termios.h for many years.  Looking around the web, I
found discussions about FreeBSD folks trying to get rid of old sgtty.h
a decade ago:

  https://lists.freebsd.org/pipermail/freebsd-hackers/2007-March/019983.html

So I think support for termio and sgtty in GDB is just dead code that
is never compiled anywhere and is just getting in the way.  For
example, serial_noflush_set_tty_state and the raw<->cooked concerns
mentioned in inflow.c only exist because of sgtty (see
hardwire_noflush_set_tty_state).

Regtested on GNU/Linux.

Confirmed that I can still build Solaris, DJGPP and AIX GDB and that
the resulting GDBs still include the termios.h-guarded code.
Confirmed mingw-w64 GDB still builds and skips the termios.h-guarded
code.

gdb/ChangeLog:
2017-11-06  Pedro Alves  <palves@redhat.com>

	* Makefile.in (SER_HARDWIRE): Update comment.
	(HFILES_NO_SRCDIR): Remove gdb_termios.h.
	* common/gdb_termios.h: Delete file.
	* common/job-control.c: Include termios.h and unistd.h instead of
	gdb_termios.h.
	(gdb_setpgid): Remove HAVE_TERMIOS || TIOCGPGRP preprocessor
	check.
	(have_job_control): Check HAVE_TERMIOS_H instead of HAVE_TERMIOS.
	Remove sgtty code.
	* configure.ac: No longer check for termio.h and sgtty.h.
	* configure: Regenerate.
	* inflow.c: Include termios.h instead of gdb_termios.h.  Replace
	PROCESS_GROUP_TYPE checks with HAVE_TERMIOS_H checks throughout.
	Replace PROCESS_GROUP_TYPE references with pid_t references
	throughout.
	(gdb_getpgrp): Delete.
	(set_initial_gdb_ttystate): Use tcgetpgrp instead of gdb_getpgrp.
	(child_terminal_inferior): Remove comment.  Remove sgtty code.
	(child_terminal_ours_1): Use tcgetpgrp directly instead of
	gdb_getpgrp.  Use serial_set_tty_state instead aof
	serial_noflush_set_tty_state.  Remove sgtty code.
	* inflow.h: Include unistd.h instead of gdb_termios.h.  Replace
	PROCESS_GROUP_TYPE check with HAVE_TERMIOS_H check.
	(inferior_process_group): Now returns pid_t.
	* ser-base.c (ser_base_noflush_set_tty_state): Delete.
	* ser-base.h (ser_base_noflush_set_tty_state): Delete.
	* ser-event.c (serial_event_ops): Update.
	* ser-go32.c (dos_noflush_set_tty_state): Delete.
	(dos_ops): Update.
	* ser-mingw.c (hardwire_ops, tty_ops, pipe_ops, tcp_ops): Update.
	* ser-pipe.c (pipe_ops): Update.
	* ser-tcp.c (tcp_ops): Update.
	* ser-unix.c: Include termios.h instead of gdb_termios.h.  Remove
	HAVE_TERMIOS checks.
	[HAVE_TERMIO] (struct hardwire_ttystate): Delete.
	[HAVE_SGTTY] (struct hardwire_ttystate): Delete.
	(get_tty_state, set_tty_state): Drop termio and sgtty code, and
	assume termios.
	(hardwire_noflush_set_tty_state): Delete.
	(hardwire_print_tty_state, hardwire_drain_output)
	(hardwire_flush_output, hardwire_flush_input)
	(hardwire_send_break, hardwire_raw, hardwire_setbaudrate)
	(hardwire_setstopbits, hardwire_setparity): Drop termio and sgtty
	code, and assume termios.
	(hardwire_ops): Update.
	(_initialize_ser_hardwire): Remove HAVE_TERMIOS check.
	* serial.c (serial_noflush_set_tty_state): Delete.
	* serial.h (serial_noflush_set_tty_state): Delete.
	(serial_ops::noflush_set_tty_state): Delete.

gdb/gdbserver/ChangeLog:
2017-11-06  Pedro Alves  <palves@redhat.com>

	* configure.ac: No longer check for termio.h and sgtty.h.
	* configure: Regenerate.
	* remote-utils.c: Include termios.h instead of gdb_termios.h.
	(remote_open): Check HAVE_TERMIOS_H instead of HAVE_TERMIOS.
	Remove termio and sgtty code.

1 files changed, 1 insertions, 263 deletions

diff --git a/gdb/ser-unix.c b/gdb/ser-unix.c
index 53c33e663f..3cbb77fb98 100644
--- a/gdb/ser-unix.c
+++ b/gdb/ser-unix.c
@@ -31,9 +31,7 @@
 #include "gdb_select.h"
 #include "gdbcmd.h"
 #include "filestuff.h"
-#include "gdb_termios.h"
-
-#ifdef HAVE_TERMIOS
+#include <termios.h>
 
 struct hardwire_ttystate
   {
@@ -51,32 +49,6 @@ show_serial_hwflow (struct ui_file *file, int from_tty,
 }
 #endif
 
-#endif /* termios */
-
-#ifdef HAVE_TERMIO
-
-/* It is believed that all systems which have added job control to SVR3
-   (e.g. sco) have also added termios.  Even if not, trying to figure out
-   all the variations (TIOCGPGRP vs. TCGETPGRP, etc.) would be pretty
-   bewildering.  So we don't attempt it.  */
-
-struct hardwire_ttystate
-  {
-    struct termio termio;
-  };
-#endif /* termio */
-
-#ifdef HAVE_SGTTY
-struct hardwire_ttystate
-  {
-    struct sgttyb sgttyb;
-    struct tchars tc;
-    struct ltchars ltc;
-    /* Line discipline flags.  */
-    int lmode;
-  };
-#endif /* sgtty */
-
 static int hardwire_open (struct serial *scb, const char *name);
 static void hardwire_raw (struct serial *scb);
 static int rate_to_code (int rate);
@@ -89,8 +61,6 @@ static int set_tty_state (struct serial *scb,
 			  struct hardwire_ttystate * state);
 static serial_ttystate hardwire_get_tty_state (struct serial *scb);
 static int hardwire_set_tty_state (struct serial *scb, serial_ttystate state);
-static int hardwire_noflush_set_tty_state (struct serial *, serial_ttystate,
-					   serial_ttystate);
 static void hardwire_print_tty_state (struct serial *, serial_ttystate,
 				      struct ui_file *);
 static int hardwire_drain_output (struct serial *);
@@ -114,61 +84,19 @@ hardwire_open (struct serial *scb, const char *name)
 static int
 get_tty_state (struct serial *scb, struct hardwire_ttystate *state)
 {
-#ifdef HAVE_TERMIOS
   if (tcgetattr (scb->fd, &state->termios) < 0)
     return -1;
 
   return 0;
-#endif
-
-#ifdef HAVE_TERMIO
-  if (ioctl (scb->fd, TCGETA, &state->termio) < 0)
-    return -1;
-  return 0;
-#endif
-
-#ifdef HAVE_SGTTY
-  if (ioctl (scb->fd, TIOCGETP, &state->sgttyb) < 0)
-    return -1;
-  if (ioctl (scb->fd, TIOCGETC, &state->tc) < 0)
-    return -1;
-  if (ioctl (scb->fd, TIOCGLTC, &state->ltc) < 0)
-    return -1;
-  if (ioctl (scb->fd, TIOCLGET, &state->lmode) < 0)
-    return -1;
-
-  return 0;
-#endif
 }
 
 static int
 set_tty_state (struct serial *scb, struct hardwire_ttystate *state)
 {
-#ifdef HAVE_TERMIOS
   if (tcsetattr (scb->fd, TCSANOW, &state->termios) < 0)
     return -1;
 
   return 0;
-#endif
-
-#ifdef HAVE_TERMIO
-  if (ioctl (scb->fd, TCSETA, &state->termio) < 0)
-    return -1;
-  return 0;
-#endif
-
-#ifdef HAVE_SGTTY
-  if (ioctl (scb->fd, TIOCSETN, &state->sgttyb) < 0)
-    return -1;
-  if (ioctl (scb->fd, TIOCSETC, &state->tc) < 0)
-    return -1;
-  if (ioctl (scb->fd, TIOCSLTC, &state->ltc) < 0)
-    return -1;
-  if (ioctl (scb->fd, TIOCLSET, &state->lmode) < 0)
-    return -1;
-
-  return 0;
-#endif
 }
 
 static serial_ttystate
@@ -205,39 +133,6 @@ hardwire_set_tty_state (struct serial *scb, serial_ttystate ttystate)
   return set_tty_state (scb, state);
 }
 
-static int
-hardwire_noflush_set_tty_state (struct serial *scb,
-				serial_ttystate new_ttystate,
-				serial_ttystate old_ttystate)
-{
-  struct hardwire_ttystate new_state;
-#ifdef HAVE_SGTTY
-  struct hardwire_ttystate *state = (struct hardwire_ttystate *) old_ttystate;
-#endif
-
-  new_state = *(struct hardwire_ttystate *) new_ttystate;
-
-  /* Don't change in or out of raw mode; we don't want to flush input.
-     termio and termios have no such restriction; for them flushing input
-     is separate from setting the attributes.  */
-
-#ifdef HAVE_SGTTY
-  if (state->sgttyb.sg_flags & RAW)
-    new_state.sgttyb.sg_flags |= RAW;
-  else
-    new_state.sgttyb.sg_flags &= ~RAW;
-
-  /* I'm not sure whether this is necessary; the manpage just mentions
-     RAW not CBREAK.  */
-  if (state->sgttyb.sg_flags & CBREAK)
-    new_state.sgttyb.sg_flags |= CBREAK;
-  else
-    new_state.sgttyb.sg_flags &= ~CBREAK;
-#endif
-
-  return set_tty_state (scb, &new_state);
-}
-
 static void
 hardwire_print_tty_state (struct serial *scb,
 			  serial_ttystate ttystate,
@@ -246,7 +141,6 @@ hardwire_print_tty_state (struct serial *scb,
   struct hardwire_ttystate *state = (struct hardwire_ttystate *) ttystate;
   int i;
 
-#ifdef HAVE_TERMIOS
   fprintf_filtered (stream, "c_iflag = 0x%x, c_oflag = 0x%x,\n",
 		    (int) state->termios.c_iflag,
 		    (int) state->termios.c_oflag);
@@ -262,36 +156,6 @@ hardwire_print_tty_state (struct serial *scb,
   for (i = 0; i < NCCS; i += 1)
     fprintf_filtered (stream, "0x%x ", state->termios.c_cc[i]);
   fprintf_filtered (stream, "\n");
-#endif
-
-#ifdef HAVE_TERMIO
-  fprintf_filtered (stream, "c_iflag = 0x%x, c_oflag = 0x%x,\n",
-		    state->termio.c_iflag, state->termio.c_oflag);
-  fprintf_filtered (stream, "c_cflag = 0x%x, c_lflag = 0x%x, c_line = 0x%x.\n",
-		    state->termio.c_cflag, state->termio.c_lflag,
-		    state->termio.c_line);
-  fprintf_filtered (stream, "c_cc: ");
-  for (i = 0; i < NCC; i += 1)
-    fprintf_filtered (stream, "0x%x ", state->termio.c_cc[i]);
-  fprintf_filtered (stream, "\n");
-#endif
-
-#ifdef HAVE_SGTTY
-  fprintf_filtered (stream, "sgttyb.sg_flags = 0x%x.\n",
-		    state->sgttyb.sg_flags);
-
-  fprintf_filtered (stream, "tchars: ");
-  for (i = 0; i < (int) sizeof (struct tchars); i++)
-    fprintf_filtered (stream, "0x%x ", ((unsigned char *) &state->tc)[i]);
-  fprintf_filtered (stream, "\n");
-
-  fprintf_filtered (stream, "ltchars: ");
-  for (i = 0; i < (int) sizeof (struct ltchars); i++)
-    fprintf_filtered (stream, "0x%x ", ((unsigned char *) &state->ltc)[i]);
-  fprintf_filtered (stream, "\n");
-
-  fprintf_filtered (stream, "lmode:  0x%x\n", state->lmode);
-#endif
 }
 
 /* Wait for the output to drain away, as opposed to flushing
@@ -300,48 +164,13 @@ hardwire_print_tty_state (struct serial *scb,
 static int
 hardwire_drain_output (struct serial *scb)
 {
-#ifdef HAVE_TERMIOS
   return tcdrain (scb->fd);
-#endif
-
-#ifdef HAVE_TERMIO
-  return ioctl (scb->fd, TCSBRK, 1);
-#endif
-
-#ifdef HAVE_SGTTY
-  /* Get the current state and then restore it using TIOCSETP,
-     which should cause the output to drain and pending input
-     to be discarded.  */
-  {
-    struct hardwire_ttystate state;
-
-    if (get_tty_state (scb, &state))
-      {
-	return (-1);
-      }
-    else
-      {
-	return (ioctl (scb->fd, TIOCSETP, &state.sgttyb));
-      }
-  }
-#endif
 }
 
 static int
 hardwire_flush_output (struct serial *scb)
 {
-#ifdef HAVE_TERMIOS
   return tcflush (scb->fd, TCOFLUSH);
-#endif
-
-#ifdef HAVE_TERMIO
-  return ioctl (scb->fd, TCFLSH, 1);
-#endif
-
-#ifdef HAVE_SGTTY
-  /* This flushes both input and output, but we can't do better.  */
-  return ioctl (scb->fd, TIOCFLUSH, 0);
-#endif
 }
 
 static int
@@ -349,45 +178,13 @@ hardwire_flush_input (struct serial *scb)
 {
   ser_base_flush_input (scb);
 
-#ifdef HAVE_TERMIOS
   return tcflush (scb->fd, TCIFLUSH);
-#endif
-
-#ifdef HAVE_TERMIO
-  return ioctl (scb->fd, TCFLSH, 0);
-#endif
-
-#ifdef HAVE_SGTTY
-  /* This flushes both input and output, but we can't do better.  */
-  return ioctl (scb->fd, TIOCFLUSH, 0);
-#endif
 }
 
 static int
 hardwire_send_break (struct serial *scb)
 {
-#ifdef HAVE_TERMIOS
   return tcsendbreak (scb->fd, 0);
-#endif
-
-#ifdef HAVE_TERMIO
-  return ioctl (scb->fd, TCSBRK, 0);
-#endif
-
-#ifdef HAVE_SGTTY
-  {
-    int status;
-
-    status = ioctl (scb->fd, TIOCSBRK, 0);
-
-    /* Can't use usleep; it doesn't exist in BSD 4.2.  */
-    /* Note that if this gdb_select() is interrupted by a signal it will not
-       wait the full length of time.  I think that is OK.  */
-    gdb_usleep (250000);
-    status = ioctl (scb->fd, TIOCCBRK, 0);
-    return status;
-  }
-#endif
 }
 
 static void
@@ -399,7 +196,6 @@ hardwire_raw (struct serial *scb)
     fprintf_unfiltered (gdb_stderr, "get_tty_state failed: %s\n",
 			safe_strerror (errno));
 
-#ifdef HAVE_TERMIOS
   state.termios.c_iflag = 0;
   state.termios.c_oflag = 0;
   state.termios.c_lflag = 0;
@@ -420,22 +216,6 @@ hardwire_raw (struct serial *scb)
 #endif
   state.termios.c_cc[VMIN] = 0;
   state.termios.c_cc[VTIME] = 0;
-#endif
-
-#ifdef HAVE_TERMIO
-  state.termio.c_iflag = 0;
-  state.termio.c_oflag = 0;
-  state.termio.c_lflag = 0;
-  state.termio.c_cflag &= ~CSIZE;
-  state.termio.c_cflag |= CLOCAL | CS8;
-  state.termio.c_cc[VMIN] = 0;
-  state.termio.c_cc[VTIME] = 0;
-#endif
-
-#ifdef HAVE_SGTTY
-  state.sgttyb.sg_flags |= RAW | ANYP;
-  state.sgttyb.sg_flags &= ~(CBREAK | ECHO);
-#endif
 
   if (set_tty_state (scb, &state))
     fprintf_unfiltered (gdb_stderr, "set_tty_state failed: %s\n",
@@ -604,24 +384,8 @@ hardwire_setbaudrate (struct serial *scb, int rate)
   if (get_tty_state (scb, &state))
     return -1;
 
-#ifdef HAVE_TERMIOS
   cfsetospeed (&state.termios, baud_code);
   cfsetispeed (&state.termios, baud_code);
-#endif
-
-#ifdef HAVE_TERMIO
-#ifndef CIBAUD
-#define CIBAUD CBAUD
-#endif
-
-  state.termio.c_cflag &= ~(CBAUD | CIBAUD);
-  state.termio.c_cflag |= baud_code;
-#endif
-
-#ifdef HAVE_SGTTY
-  state.sgttyb.sg_ispeed = baud_code;
-  state.sgttyb.sg_ospeed = baud_code;
-#endif
 
   return set_tty_state (scb, &state);
 }
@@ -648,23 +412,10 @@ hardwire_setstopbits (struct serial *scb, int num)
       return 1;
     }
 
-#ifdef HAVE_TERMIOS
   if (!newbit)
     state.termios.c_cflag &= ~CSTOPB;
   else
     state.termios.c_cflag |= CSTOPB;	/* two bits */
-#endif
-
-#ifdef HAVE_TERMIO
-  if (!newbit)
-    state.termio.c_cflag &= ~CSTOPB;
-  else
-    state.termio.c_cflag |= CSTOPB;	/* two bits */
-#endif
-
-#ifdef HAVE_SGTTY
-  return 0;			/* sgtty doesn't support this */
-#endif
 
   return set_tty_state (scb, &state);
 }
@@ -697,19 +448,9 @@ hardwire_setparity (struct serial *scb, int parity)
       return -1;
     }
 
-#ifdef HAVE_TERMIOS
   state.termios.c_cflag &= ~(PARENB | PARODD);
   state.termios.c_cflag |= newparity;
-#endif
 
-#ifdef HAVE_TERMIO
-  state.termio.c_cflag &= ~(PARENB | PARODD);
-  state.termio.c_cflag |= newparity;
-#endif
-
-#ifdef HAVE_SGTTY
-  return 0;            /* sgtty doesn't support this */
-#endif
   return set_tty_state (scb, &state);
 }
 
@@ -744,7 +485,6 @@ static const struct serial_ops hardwire_ops =
   hardwire_copy_tty_state,
   hardwire_set_tty_state,
   hardwire_print_tty_state,
-  hardwire_noflush_set_tty_state,
   hardwire_setbaudrate,
   hardwire_setstopbits,
   hardwire_setparity,
@@ -759,7 +499,6 @@ _initialize_ser_hardwire (void)
 {
   serial_add_interface (&hardwire_ops);
 
-#ifdef HAVE_TERMIOS
 #ifdef CRTSCTS
   add_setshow_boolean_cmd ("remoteflow", no_class,
 			   &serial_hwflow, _("\
@@ -771,7 +510,6 @@ when debugging using remote targets."),
 			   show_serial_hwflow,
 			   &setlist, &showlist);
 #endif
-#endif
 }
 
 int