gdb/serial.h

   1 /* Remote serial support interface definitions for GDB, the GNU Debugger.
   2    Copyright (C) 1992-2020 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef SERIAL_H
  20 #define SERIAL_H
  21
  22 #ifdef USE_WIN32API
  23 #include <winsock2.h>
  24 #include <windows.h>
  25 #endif
  26
  27 struct ui_file;
  28
  29 /* For most routines, if a failure is indicated, then errno should be
  30    examined.  */
  31
  32 /* Terminal state pointer.  This is specific to each type of
  33    interface.  */
  34
  35 typedef void *serial_ttystate;
  36 struct serial;
  37 struct serial_ops;
  38
  39 /* Create a new serial for OPS.  The new serial is not opened.  */
  40
  41 /* Try to open NAME.  Returns a new `struct serial *' on success, NULL
  42    on failure.  The new serial object has a reference count of 1.
  43    Note that some open calls can block and, if possible, should be
  44    written to be non-blocking, with calls to ui_look_hook so they can
  45    be cancelled.  An async interface for open could be added to GDB if
  46    necessary.  */
  47
  48 extern struct serial *serial_open (const char *name);
  49
  50 /* Open a new serial stream using OPS.  */
  51
  52 extern struct serial *serial_open_ops (const struct serial_ops *ops);
  53
  54 /* Returns true if SCB is open.  */
  55
  56 extern int serial_is_open (struct serial *scb);
  57
  58 /* Find an already opened serial stream using a file handle.  */
  59
  60 extern struct serial *serial_for_fd (int fd);
  61
  62 /* Open a new serial stream using a file handle.  */
  63
  64 extern struct serial *serial_fdopen (const int fd);
  65
  66 /* Push out all buffers, close the device and unref SCB.  */
  67
  68 extern void serial_close (struct serial *scb);
  69
  70 /* Increment reference count of SCB.  */
  71
  72 extern void serial_ref (struct serial *scb);
  73
  74 /* Decrement reference count of SCB.  */
  75
  76 extern void serial_unref (struct serial *scb);
  77
  78 /* Create a pipe, and put the read end in FILDES[0], and the write end
  79    in FILDES[1].  Returns 0 for success, negative value for error (in
  80    which case errno contains the error).  */
  81
  82 extern int gdb_pipe (int fildes[2]);
  83
  84 /* Create a pipe with each end wrapped in a `struct serial' interface.
  85    Put the read end in scbs[0], and the write end in scbs[1].  Returns
  86    0 for success, negative value for error (in which case errno
  87    contains the error).  */
  88
  89 extern int serial_pipe (struct serial *scbs[2]);
  90
  91 /* Push out all buffers and destroy SCB without closing the device.  */
  92
  93 extern void serial_un_fdopen (struct serial *scb);
  94
  95 /* Read one char from the serial device with TIMEOUT seconds to wait
  96    or -1 to wait forever.  Use timeout of 0 to effect a poll.
  97    Infinite waits are not permitted.  Returns unsigned char if ok, else
  98    one of the following codes.  Note that all error return-codes are
  99    guaranteed to be < 0.  */
 100
 101 enum serial_rc {
 102   SERIAL_ERROR = -1,    /* General error.  */
 103   SERIAL_TIMEOUT = -2,  /* Timeout or data-not-ready during read.
 104                            Unfortunately, through
 105                            deprecated_ui_loop_hook (), this can also
 106                            be a QUIT indication.  */
 107   SERIAL_EOF = -3       /* General end-of-file or remote target
 108                            connection closed, indication.  Includes
 109                            things like the line dropping dead.  */
 110 };
 111
 112 extern int serial_readchar (struct serial *scb, int timeout);
 113
 114 /* Write COUNT bytes from BUF to the port SCB.  Returns 0 for
 115    success, non-zero for failure.  */
 116
 117 extern int serial_write (struct serial *scb, const void *buf, size_t count);
 118
 119 /* Write a printf style string onto the serial port.  */
 120
 121 extern void serial_printf (struct serial *desc,
 122                            const char *,...) ATTRIBUTE_PRINTF (2, 3);
 123
 124 /* Allow pending output to drain.  */
 125
 126 extern int serial_drain_output (struct serial *);
 127
 128 /* Flush (discard) pending output.  Might also flush input (if this
 129    system can't flush only output).  */
 130
 131 extern int serial_flush_output (struct serial *);
 132
 133 /* Flush pending input.  Might also flush output (if this system can't
 134    flush only input).  */
 135
 136 extern int serial_flush_input (struct serial *);
 137
 138 /* Send a break between 0.25 and 0.5 seconds long.  */
 139
 140 extern int serial_send_break (struct serial *scb);
 141
 142 /* Turn the port into raw mode.  */
 143
 144 extern void serial_raw (struct serial *scb);
 145
 146 /* Return a pointer to a newly malloc'd ttystate containing the state
 147    of the tty.  */
 148
 149 extern serial_ttystate serial_get_tty_state (struct serial *scb);
 150
 151 /* Return a pointer to a newly malloc'd ttystate containing a copy
 152    of the state in TTYSTATE.  */
 153
 154 extern serial_ttystate serial_copy_tty_state (struct serial *scb,
 155                                               serial_ttystate ttystate);
 156
 157 /* Set the state of the tty to TTYSTATE.  The change is immediate.
 158    When changing to or from raw mode, input might be discarded.
 159    Returns 0 for success, negative value for error (in which case
 160    errno contains the error).  */
 161
 162 extern int serial_set_tty_state (struct serial *scb, serial_ttystate ttystate);
 163
 164 /* printf_filtered a user-comprehensible description of ttystate on
 165    the specified STREAM.  FIXME: At present this sends output to the
 166    default stream - GDB_STDOUT.  */
 167
 168 extern void serial_print_tty_state (struct serial *scb,
 169                                     serial_ttystate ttystate,
 170                                     struct ui_file *);
 171
 172 /* Set the baudrate to the decimal value supplied.  Returns 0 for
 173    success, -1 for failure.  */
 174
 175 extern int serial_setbaudrate (struct serial *scb, int rate);
 176
 177 /* Set the number of stop bits to the value specified.  Returns 0 for
 178    success, -1 for failure.  */
 179
 180 #define SERIAL_1_STOPBITS 1
 181 #define SERIAL_1_AND_A_HALF_STOPBITS 2  /* 1.5 bits, snicker...  */
 182 #define SERIAL_2_STOPBITS 3
 183
 184 extern int serial_setstopbits (struct serial *scb, int num);
 185
 186 #define GDBPARITY_NONE     0
 187 #define GDBPARITY_ODD      1
 188 #define GDBPARITY_EVEN     2
 189
 190 /* Set parity for serial port. Returns 0 for success, -1 for failure.  */
 191
 192 extern int serial_setparity (struct serial *scb, int parity);
 193
 194 /* Asynchronous serial interface: */
 195
 196 /* Can the serial device support asynchronous mode?  */
 197
 198 extern int serial_can_async_p (struct serial *scb);
 199
 200 /* Has the serial device been put in asynchronous mode?  */
 201
 202 extern int serial_is_async_p (struct serial *scb);
 203
 204 /* For ASYNC enabled devices, register a callback and enable
 205    asynchronous mode.  To disable asynchronous mode, register a NULL
 206    callback.  */
 207
 208 typedef void (serial_event_ftype) (struct serial *scb, void *context);
 209 extern void serial_async (struct serial *scb,
 210                           serial_event_ftype *handler, void *context);
 211
 212 /* Trace/debug mechanism.
 213
 214    serial_debug() enables/disables internal debugging.
 215    serial_debug_p() indicates the current debug state.  */
 216
 217 extern void serial_debug (struct serial *scb, int debug_p);
 218
 219 extern int serial_debug_p (struct serial *scb);
 220
 221
 222 /* Details of an instance of a serial object.  */
 223
 224 struct serial
 225   {
 226     /* serial objects are ref counted (but not the underlying
 227        connection, just the object's lifetime in memory).  */
 228     int refcnt;
 229
 230     int fd;                     /* File descriptor */
 231     /* File descriptor for a separate error stream that should be
 232        immediately forwarded to gdb_stderr.  This may be -1.
 233        If != -1, this descriptor should be non-blocking or
 234        ops->avail should be non-NULL.  */
 235     int error_fd;
 236     const struct serial_ops *ops; /* Function vector */
 237     void *state;                /* Local context info for open FD */
 238     serial_ttystate ttystate;   /* Not used (yet) */
 239     int bufcnt;                 /* Amount of data remaining in receive
 240                                    buffer.  -ve for sticky errors.  */
 241     unsigned char *bufp;        /* Current byte */
 242     unsigned char buf[BUFSIZ];  /* Da buffer itself */
 243     char *name;                 /* The name of the device or host */
 244     struct serial *next;        /* Pointer to the next `struct serial *' */
 245     int debug_p;                /* Trace this serial devices operation.  */
 246     int async_state;            /* Async internal state.  */
 247     void *async_context;        /* Async event thread's context */
 248     serial_event_ftype *async_handler;/* Async event handler */
 249   };
 250
 251 struct serial_ops
 252   {
 253     const char *name;
 254     int (*open) (struct serial *, const char *name);
 255     void (*close) (struct serial *);
 256     int (*fdopen) (struct serial *, int fd);
 257     int (*readchar) (struct serial *, int timeout);
 258     int (*write) (struct serial *, const void *buf, size_t count);
 259     /* Discard pending output */
 260     int (*flush_output) (struct serial *);
 261     /* Discard pending input */
 262     int (*flush_input) (struct serial *);
 263     int (*send_break) (struct serial *);
 264     void (*go_raw) (struct serial *);
 265     serial_ttystate (*get_tty_state) (struct serial *);
 266     serial_ttystate (*copy_tty_state) (struct serial *, serial_ttystate);
 267     int (*set_tty_state) (struct serial *, serial_ttystate);
 268     void (*print_tty_state) (struct serial *, serial_ttystate,
 269                              struct ui_file *);
 270     int (*setbaudrate) (struct serial *, int rate);
 271     int (*setstopbits) (struct serial *, int num);
 272     /* Set the value PARITY as parity setting for serial object.
 273        Return 0 in the case of success.  */
 274     int (*setparity) (struct serial *, int parity);
 275     /* Wait for output to drain.  */
 276     int (*drain_output) (struct serial *);
 277     /* Change the serial device into/out of asynchronous mode, call
 278        the specified function when ever there is something
 279        interesting.  */
 280     void (*async) (struct serial *scb, int async_p);
 281     /* Perform a low-level read operation, reading (at most) COUNT
 282        bytes into SCB->BUF.  Return zero at end of file.  */
 283     int (*read_prim)(struct serial *scb, size_t count);
 284     /* Perform a low-level write operation, writing (at most) COUNT
 285        bytes from BUF.  */
 286     int (*write_prim)(struct serial *scb, const void *buf, size_t count);
 287     /* Return that number of bytes that can be read from FD
 288        without blocking.  Return value of -1 means that the
 289        read will not block even if less that requested bytes
 290        are available.  */
 291     int (*avail)(struct serial *scb, int fd);
 292
 293 #ifdef USE_WIN32API
 294     /* Return a handle to wait on, indicating available data from SCB
 295        when signaled, in *READ.  Return a handle indicating errors
 296        in *EXCEPT.  */
 297     void (*wait_handle) (struct serial *scb, HANDLE *read, HANDLE *except);
 298     void (*done_wait_handle) (struct serial *scb);
 299 #endif /* USE_WIN32API */
 300   };
 301
 302 /* Add a new serial interface to the interface list.  */
 303
 304 extern void serial_add_interface (const struct serial_ops * optable);
 305
 306 /* File in which to record the remote debugging session.  */
 307
 308 extern void serial_log_command (struct target_ops *self, const char *);
 309
 310 #ifdef USE_WIN32API
 311
 312 /* Windows-only: find or create handles that we can wait on for this
 313    serial device.  */
 314 extern void serial_wait_handle (struct serial *, HANDLE *, HANDLE *);
 315
 316 /* Windows-only: signal that we are done with the wait handles.  */
 317 extern void serial_done_wait_handle (struct serial *);
 318
 319 #endif /* USE_WIN32API */
 320
 321 #endif /* SERIAL_H */