text: /* Remote serial support interface definitions for GDB, the GNU Debugger.
     Copyright (C) 1992-2019 Free Software Foundation, Inc.
  
     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/>.  */
  
  #ifndef SERIAL_H
  #define SERIAL_H
  
  #ifdef USE_WIN32API
  #include <winsock2.h>
  #include <windows.h>
  #endif
  
  struct ui_file;
  
  /* For most routines, if a failure is indicated, then errno should be
     examined.  */
  
  /* Terminal state pointer.  This is specific to each type of
     interface.  */
  
  typedef void *serial_ttystate;
  struct serial;
  struct serial_ops;
  
  /* Create a new serial for OPS.  The new serial is not opened.  */
  
  /* Try to open NAME.  Returns a new `struct serial *' on success, NULL
     on failure.  The new serial object has a reference count of 1.
     Note that some open calls can block and, if possible, should be
     written to be non-blocking, with calls to ui_look_hook so they can
     be cancelled.  An async interface for open could be added to GDB if
     necessary.  */
  
  extern struct serial *serial_open (const char *name);
  
  /* Open a new serial stream using OPS.  */
  
  extern struct serial *serial_open_ops (const struct serial_ops *ops);
  
  /* Returns true if SCB is open.  */
  
  extern int serial_is_open (struct serial *scb);
  
  /* Find an already opened serial stream using a file handle.  */
  
  extern struct serial *serial_for_fd (int fd);
  
  /* Open a new serial stream using a file handle.  */
  
  extern struct serial *serial_fdopen (const int fd);
  
  /* Push out all buffers, close the device and unref SCB.  */
  
  extern void serial_close (struct serial *scb);
  
  /* Increment reference count of SCB.  */
  
  extern void serial_ref (struct serial *scb);
  
  /* Decrement reference count of SCB.  */
  
  extern void serial_unref (struct serial *scb);
  
  /* Create a pipe, and put the read end in FILDES[0], and the write end
     in FILDES[1].  Returns 0 for success, negative value for error (in
     which case errno contains the error).  */
  
  extern int gdb_pipe (int fildes[2]);
  
  /* Create a pipe with each end wrapped in a `struct serial' interface.
     Put the read end in scbs[0], and the write end in scbs[1].  Returns
     0 for success, negative value for error (in which case errno
     contains the error).  */
  
  extern int serial_pipe (struct serial *scbs[2]);
  
  /* Push out all buffers and destroy SCB without closing the device.  */
  
  extern void serial_un_fdopen (struct serial *scb);
  
  /* Read one char from the serial device with TIMEOUT seconds to wait
     or -1 to wait forever.  Use timeout of 0 to effect a poll.
     Infinite waits are not permitted.  Returns unsigned char if ok, else
     one of the following codes.  Note that all error return-codes are
     guaranteed to be < 0.  */
  
  enum serial_rc {
    SERIAL_ERROR = -1,	/* General error.  */
    SERIAL_TIMEOUT = -2,	/* Timeout or data-not-ready during read.
  			   Unfortunately, through
  			   deprecated_ui_loop_hook (), this can also
  			   be a QUIT indication.  */
    SERIAL_EOF = -3	/* General end-of-file or remote target
  			   connection closed, indication.  Includes
  			   things like the line dropping dead.  */
  };
  
  extern int serial_readchar (struct serial *scb, int timeout);
  
  /* Write COUNT bytes from BUF to the port SCB.  Returns 0 for
     success, non-zero for failure.  */
  
  extern int serial_write (struct serial *scb, const void *buf, size_t count);
  
  /* Write a printf style string onto the serial port.  */
  
  extern void serial_printf (struct serial *desc, 
  			   const char *,...) ATTRIBUTE_PRINTF (2, 3);
  
  /* Allow pending output to drain.  */
  
  extern int serial_drain_output (struct serial *);
  
  /* Flush (discard) pending output.  Might also flush input (if this
     system can't flush only output).  */
  
  extern int serial_flush_output (struct serial *);
  
  /* Flush pending input.  Might also flush output (if this system can't
     flush only input).  */
  
  extern int serial_flush_input (struct serial *);
  
  /* Send a break between 0.25 and 0.5 seconds long.  */
  
  extern int serial_send_break (struct serial *scb);
  
  /* Turn the port into raw mode.  */
  
  extern void serial_raw (struct serial *scb);
  
  /* Return a pointer to a newly malloc'd ttystate containing the state
     of the tty.  */
  
  extern serial_ttystate serial_get_tty_state (struct serial *scb);
  
  /* Return a pointer to a newly malloc'd ttystate containing a copy
     of the state in TTYSTATE.  */
  
  extern serial_ttystate serial_copy_tty_state (struct serial *scb,
  					      serial_ttystate ttystate);
  
  /* Set the state of the tty to TTYSTATE.  The change is immediate.
     When changing to or from raw mode, input might be discarded.
     Returns 0 for success, negative value for error (in which case
     errno contains the error).  */
  
  extern int serial_set_tty_state (struct serial *scb, serial_ttystate ttystate);
  
  /* printf_filtered a user-comprehensible description of ttystate on
     the specified STREAM.  FIXME: At present this sends output to the
     default stream - GDB_STDOUT.  */
  
  extern void serial_print_tty_state (struct serial *scb,
  				    serial_ttystate ttystate,
  				    struct ui_file *);
  
  /* Set the baudrate to the decimal value supplied.  Returns 0 for
     success, -1 for failure.  */
  
  extern int serial_setbaudrate (struct serial *scb, int rate);
  
  /* Set the number of stop bits to the value specified.  Returns 0 for
     success, -1 for failure.  */
  
  #define SERIAL_1_STOPBITS 1
  #define SERIAL_1_AND_A_HALF_STOPBITS 2	/* 1.5 bits, snicker...  */
  #define SERIAL_2_STOPBITS 3
  
  extern int serial_setstopbits (struct serial *scb, int num);
  
  #define GDBPARITY_NONE     0
  #define GDBPARITY_ODD      1
  #define GDBPARITY_EVEN     2
  
  /* Set parity for serial port. Returns 0 for success, -1 for failure.  */
  
  extern int serial_setparity (struct serial *scb, int parity);
  
  /* Asynchronous serial interface: */
  
  /* Can the serial device support asynchronous mode?  */
  
  extern int serial_can_async_p (struct serial *scb);
  
  /* Has the serial device been put in asynchronous mode?  */
  
  extern int serial_is_async_p (struct serial *scb);
  
  /* For ASYNC enabled devices, register a callback and enable
     asynchronous mode.  To disable asynchronous mode, register a NULL
     callback.  */
  
  typedef void (serial_event_ftype) (struct serial *scb, void *context);
  extern void serial_async (struct serial *scb,
  			  serial_event_ftype *handler, void *context);
  
  /* Trace/debug mechanism.
  
     serial_debug() enables/disables internal debugging.
     serial_debug_p() indicates the current debug state.  */
  
  extern void serial_debug (struct serial *scb, int debug_p);
  
  extern int serial_debug_p (struct serial *scb);
  
  
  /* Details of an instance of a serial object.  */
  
  struct serial
    {
      /* serial objects are ref counted (but not the underlying
         connection, just the object's lifetime in memory).  */
      int refcnt;
  
      int fd;			/* File descriptor */
      /* File descriptor for a separate error stream that should be
         immediately forwarded to gdb_stderr.  This may be -1.
         If != -1, this descriptor should be non-blocking or
         ops->avail should be non-NULL.  */
      int error_fd;               
      const struct serial_ops *ops; /* Function vector */
      void *state;       		/* Local context info for open FD */
      serial_ttystate ttystate;	/* Not used (yet) */
      int bufcnt;			/* Amount of data remaining in receive
  				   buffer.  -ve for sticky errors.  */
      unsigned char *bufp;	/* Current byte */
      unsigned char buf[BUFSIZ];	/* Da buffer itself */
      struct serial *next;	/* Pointer to the next `struct serial *' */
      int debug_p;		/* Trace this serial devices operation.  */
      int async_state;		/* Async internal state.  */
      void *async_context;	/* Async event thread's context */
      serial_event_ftype *async_handler;/* Async event handler */
    };
  
  struct serial_ops
    {
      const char *name;
      int (*open) (struct serial *, const char *name);
      void (*close) (struct serial *);
      int (*fdopen) (struct serial *, int fd);
      int (*readchar) (struct serial *, int timeout);
      int (*write) (struct serial *, const void *buf, size_t count);
      /* Discard pending output */
      int (*flush_output) (struct serial *);
      /* Discard pending input */
      int (*flush_input) (struct serial *);
      int (*send_break) (struct serial *);
      void (*go_raw) (struct serial *);
      serial_ttystate (*get_tty_state) (struct serial *);
      serial_ttystate (*copy_tty_state) (struct serial *, serial_ttystate);
      int (*set_tty_state) (struct serial *, serial_ttystate);
      void (*print_tty_state) (struct serial *, serial_ttystate,
  			     struct ui_file *);
      int (*setbaudrate) (struct serial *, int rate);
      int (*setstopbits) (struct serial *, int num);
      /* Set the value PARITY as parity setting for serial object.
         Return 0 in the case of success.  */
      int (*setparity) (struct serial *, int parity);
      /* Wait for output to drain.  */
      int (*drain_output) (struct serial *);
      /* Change the serial device into/out of asynchronous mode, call
         the specified function when ever there is something
         interesting.  */
      void (*async) (struct serial *scb, int async_p);
      /* Perform a low-level read operation, reading (at most) COUNT
         bytes into SCB->BUF.  Return zero at end of file.  */
      int (*read_prim)(struct serial *scb, size_t count);
      /* Perform a low-level write operation, writing (at most) COUNT
         bytes from BUF.  */
      int (*write_prim)(struct serial *scb, const void *buf, size_t count);
      /* Return that number of bytes that can be read from FD
         without blocking.  Return value of -1 means that the
         read will not block even if less that requested bytes
         are available.  */
      int (*avail)(struct serial *scb, int fd);
  
  #ifdef USE_WIN32API
      /* Return a handle to wait on, indicating available data from SCB
         when signaled, in *READ.  Return a handle indicating errors
         in *EXCEPT.  */
      void (*wait_handle) (struct serial *scb, HANDLE *read, HANDLE *except);
      void (*done_wait_handle) (struct serial *scb);
  #endif /* USE_WIN32API */
    };
  
  /* Add a new serial interface to the interface list.  */
  
  extern void serial_add_interface (const struct serial_ops * optable);
  
  /* File in which to record the remote debugging session.  */
  
  extern void serial_log_command (struct target_ops *self, const char *);
  
  #ifdef USE_WIN32API
  
  /* Windows-only: find or create handles that we can wait on for this
     serial device.  */
  extern void serial_wait_handle (struct serial *, HANDLE *, HANDLE *);
  
  /* Windows-only: signal that we are done with the wait handles.  */
  extern void serial_done_wait_handle (struct serial *);
  
  #endif /* USE_WIN32API */
  
  #endif /* SERIAL_H */
  