gdb/inflow.c

   1 /* Low level interface to ptrace, for GDB when running under Unix.
   2    Copyright (C) 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 GDB 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 1, or (at your option)
   9 any later version.
  10
  11 GDB 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 GDB; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include <stdio.h>
  21 #include "defs.h"
  22 #include "param.h"
  23 #include "frame.h"
  24 #include "inferior.h"
  25 #include "command.h"
  26 #include "signals.h"
  27 #include "terminal.h"
  28 #include "target.h"
  29
  30 #ifdef USG
  31 #include <sys/types.h>
  32 #endif
  33
  34 /* Some USG-esque systems (some of which are BSD-esque enough so that USG
  35    is not defined) want this header, and it won't do any harm.  */
  36 #include <fcntl.h>
  37
  38 #include <sys/param.h>
  39 #include <sys/dir.h>
  40 #include <signal.h>
  41
  42 extern struct target_ops child_ops;
  43
  44 /* Nonzero if we are debugging an attached outside process
  45    rather than an inferior.  */
  46
  47 int attach_flag;
  48
  49 \f
  50 /* Record terminal status separately for debugger and inferior.  */
  51
  52 static TERMINAL sg_inferior;
  53 static TERMINAL sg_ours;
  54
  55 static int tflags_inferior;
  56 static int tflags_ours;
  57
  58 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
  59 static struct tchars tc_inferior;
  60 static struct tchars tc_ours;
  61 #endif
  62
  63 #ifdef TIOCGLTC
  64 static struct ltchars ltc_inferior;
  65 static struct ltchars ltc_ours;
  66 #endif
  67
  68 #ifdef TIOCLGET
  69 static int lmode_inferior;
  70 static int lmode_ours;
  71 #endif
  72
  73 #ifdef TIOCGPGRP
  74 static int pgrp_inferior;
  75 static int pgrp_ours;
  76 #else
  77 static void (*sigint_ours) ();
  78 static void (*sigquit_ours) ();
  79 #endif /* TIOCGPGRP */
  80
  81 /* Copy of inferior_io_terminal when inferior was last started.  */
  82 static char *inferior_thisrun_terminal;
  83
  84 static void terminal_ours_1 ();
  85
  86 /* Nonzero if our terminal settings are in effect.
  87    Zero if the inferior's settings are in effect.  */
  88 static int terminal_is_ours;
  89
  90 /* Initialize the terminal settings we record for the inferior,
  91    before we actually run the inferior.  */
  92
  93 void
  94 terminal_init_inferior ()
  95 {
  96   sg_inferior = sg_ours;
  97   tflags_inferior = tflags_ours;
  98
  99 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 100   tc_inferior = tc_ours;
 101 #endif
 102
 103 #ifdef TIOCGLTC
 104   ltc_inferior = ltc_ours;
 105 #endif
 106
 107 #ifdef TIOCLGET
 108   lmode_inferior = lmode_ours;
 109 #endif
 110
 111 #ifdef TIOCGPGRP
 112   pgrp_inferior = inferior_pid;
 113 #endif /* TIOCGPGRP */
 114
 115   terminal_is_ours = 1;
 116 }
 117
 118 /* Put the inferior's terminal settings into effect.
 119    This is preparation for starting or resuming the inferior.  */
 120
 121 void
 122 terminal_inferior ()
 123 {
 124   if (terminal_is_ours && inferior_thisrun_terminal == 0)
 125     {
 126       fcntl (0, F_SETFL, tflags_inferior);
 127       fcntl (0, F_SETFL, tflags_inferior);
 128       ioctl (0, TIOCSETN, &sg_inferior);
 129
 130 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 131       ioctl (0, TIOCSETC, &tc_inferior);
 132 #endif
 133 #ifdef TIOCGLTC
 134       ioctl (0, TIOCSLTC, &ltc_inferior);
 135 #endif
 136 #ifdef TIOCLGET
 137       ioctl (0, TIOCLSET, &lmode_inferior);
 138 #endif
 139
 140 #ifdef TIOCGPGRP
 141       ioctl (0, TIOCSPGRP, &pgrp_inferior);
 142 #else
 143       sigint_ours = (void (*) ()) signal (SIGINT, SIG_IGN);
 144       sigquit_ours = (void (*) ()) signal (SIGQUIT, SIG_IGN);
 145 #endif /* TIOCGPGRP */
 146     }
 147   terminal_is_ours = 0;
 148 }
 149
 150 /* Put some of our terminal settings into effect,
 151    enough to get proper results from our output,
 152    but do not change into or out of RAW mode
 153    so that no input is discarded.
 154
 155    After doing this, either terminal_ours or terminal_inferior
 156    should be called to get back to a normal state of affairs.  */
 157
 158 void
 159 terminal_ours_for_output ()
 160 {
 161   terminal_ours_1 (1);
 162 }
 163
 164 /* Put our terminal settings into effect.
 165    First record the inferior's terminal settings
 166    so they can be restored properly later.  */
 167
 168 void
 169 terminal_ours ()
 170 {
 171   terminal_ours_1 (0);
 172 }
 173
 174 static void
 175 terminal_ours_1 (output_only)
 176      int output_only;
 177 {
 178 #ifdef TIOCGPGRP
 179   /* Ignore this signal since it will happen when we try to set the pgrp.  */
 180   void (*osigttou) ();
 181 #endif /* TIOCGPGRP */
 182
 183   /* The check for inferior_thisrun_terminal had been commented out
 184      when the call to ioctl (TIOCNOTTY) was commented out.
 185      Checking inferior_thisrun_terminal is necessary so that
 186      if GDB is running in the background, it won't block trying
 187      to do the ioctl()'s below.  */
 188   if (inferior_thisrun_terminal != 0)
 189     return;
 190
 191   if (!terminal_is_ours)
 192     {
 193       terminal_is_ours = 1;
 194
 195 #ifdef TIOCGPGRP
 196       osigttou = (void (*) ()) signal (SIGTTOU, SIG_IGN);
 197
 198       ioctl (0, TIOCGPGRP, &pgrp_inferior);
 199       ioctl (0, TIOCSPGRP, &pgrp_ours);
 200
 201       signal (SIGTTOU, osigttou);
 202 #else
 203       signal (SIGINT, sigint_ours);
 204       signal (SIGQUIT, sigquit_ours);
 205 #endif /* TIOCGPGRP */
 206
 207       tflags_inferior = fcntl (0, F_GETFL, 0);
 208       ioctl (0, TIOCGETP, &sg_inferior);
 209
 210 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 211       ioctl (0, TIOCGETC, &tc_inferior);
 212 #endif
 213 #ifdef TIOCGLTC
 214       ioctl (0, TIOCGLTC, &ltc_inferior);
 215 #endif
 216 #ifdef TIOCLGET
 217       ioctl (0, TIOCLGET, &lmode_inferior);
 218 #endif
 219     }
 220
 221 #ifdef HAVE_TERMIO
 222   sg_ours.c_lflag |= ICANON;
 223   if (output_only && !(sg_inferior.c_lflag & ICANON))
 224     sg_ours.c_lflag &= ~ICANON;
 225 #else /* not HAVE_TERMIO */
 226   sg_ours.sg_flags &= ~RAW & ~CBREAK;
 227   if (output_only)
 228     sg_ours.sg_flags |= (RAW | CBREAK) & sg_inferior.sg_flags;
 229 #endif /* not HAVE_TERMIO */
 230
 231   fcntl (0, F_SETFL, tflags_ours);
 232   fcntl (0, F_SETFL, tflags_ours);
 233   ioctl (0, TIOCSETN, &sg_ours);
 234
 235 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 236   ioctl (0, TIOCSETC, &tc_ours);
 237 #endif
 238 #ifdef TIOCGLTC
 239   ioctl (0, TIOCSLTC, &ltc_ours);
 240 #endif
 241 #ifdef TIOCLGET
 242   ioctl (0, TIOCLSET, &lmode_ours);
 243 #endif
 244
 245 #ifdef HAVE_TERMIO
 246   sg_ours.c_lflag |= ICANON;
 247 #else /* not HAVE_TERMIO */
 248   sg_ours.sg_flags &= ~RAW & ~CBREAK;
 249 #endif /* not HAVE_TERMIO */
 250 }
 251
 252 /* ARGSUSED */
 253 void
 254 term_info (arg, from_tty)
 255      char *arg;
 256      int from_tty;
 257 {
 258   target_terminal_info (arg, from_tty);
 259 }
 260
 261 void
 262 child_terminal_info (args, from_tty)
 263      char *args;
 264      int from_tty;
 265 {
 266   register int i;
 267
 268   printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
 269
 270 #ifdef HAVE_TERMIO
 271
 272   printf_filtered ("fcntl flags = 0x%x, c_iflag = 0x%x, c_oflag = 0x%x,\n",
 273           tflags_inferior, sg_inferior.c_iflag, sg_inferior.c_oflag);
 274   printf_filtered ("c_cflag = 0x%x, c_lflag = 0x%x, c_line = 0x%x.\n",
 275           sg_inferior.c_cflag, sg_inferior.c_lflag, sg_inferior.c_line);
 276   printf_filtered ("c_cc: ");
 277   for (i = 0; (i < NCC); i += 1)
 278     printf_filtered ("0x%x ", sg_inferior.c_cc[i]);
 279   printf_filtered ("\n");
 280
 281 #else /* not HAVE_TERMIO */
 282
 283   printf_filtered ("fcntl flags = 0x%x, sgttyb.sg_flags = 0x%x, owner pid = %d.\n",
 284           tflags_inferior, sg_inferior.sg_flags, pgrp_inferior);
 285
 286 #endif /* not HAVE_TERMIO */
 287
 288 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 289   printf_filtered ("tchars: ");
 290   for (i = 0; i < (int)sizeof (struct tchars); i++)
 291     printf_filtered ("0x%x ", ((char *)&tc_inferior)[i]);
 292   printf_filtered ("\n");
 293 #endif
 294
 295 #ifdef TIOCGLTC
 296   printf_filtered ("ltchars: ");
 297   for (i = 0; i < (int)sizeof (struct ltchars); i++)
 298     printf_filtered ("0x%x ", ((char *)&ltc_inferior)[i]);
 299   printf_filtered ("\n");
 300 #endif
 301
 302 #ifdef TIOCLGET
 303   printf_filtered ("lmode:  0x%x\n", lmode_inferior);
 304 #endif
 305 }
 306 \f
 307 /* NEW_TTY is called in new child processes under Unix, which will
 308    become debugger target processes.
 309    If the TTYNAME argument is non-null, we switch to that tty for further
 310    input and output.  In either case, we remember the setup.  */
 311
 312 void
 313 new_tty (ttyname)
 314      char *ttyname;
 315 {
 316   register int tty;
 317
 318   /* Save the name for later, for determining whether we and the child
 319      are sharing a tty.  */
 320   inferior_thisrun_terminal = ttyname;
 321   if (ttyname == 0)
 322     return;
 323
 324 #ifdef TIOCNOTTY
 325   /* Disconnect the child process from our controlling terminal.  */
 326   tty = open("/dev/tty", O_RDWR);
 327   if (tty > 0)
 328     {
 329       ioctl(tty, TIOCNOTTY, 0);
 330       close(tty);
 331     }
 332 #endif
 333
 334   /* Now open the specified new terminal.  */
 335
 336   tty = open(ttyname, O_RDWR);
 337   if (tty == -1)
 338     {
 339       print_sys_errmsg (ttyname, errno);
 340       _exit(1);
 341     }
 342
 343   /* Avoid use of dup2; doesn't exist on all systems.  */
 344   if (tty != 0)
 345     { close (0); dup (tty); }
 346   if (tty != 1)
 347     { close (1); dup (tty); }
 348   if (tty != 2)
 349     { close (2); dup (tty); }
 350   if (tty > 2)
 351     close(tty);
 352 }
 353 \f
 354 /* Kill the inferior process.  Make us have no inferior.  */
 355
 356 /* ARGSUSED */
 357 static void
 358 kill_command (arg, from_tty)
 359      char *arg;
 360      int from_tty;
 361 {
 362   if (inferior_pid == 0)
 363     error ("The program is not being run.");
 364   if (!query ("Kill the inferior process? "))
 365     error ("Not confirmed.");
 366   target_kill (arg, from_tty);
 367 }
 368
 369 /* The inferior process has died.  Long live the inferior!  */
 370
 371 void
 372 generic_mourn_inferior ()
 373 {
 374   inferior_pid = 0;
 375   attach_flag = 0;
 376   mark_breakpoints_out ();
 377   registers_changed ();
 378
 379 #ifdef CLEAR_DEFERRED_STORES
 380   /* Delete any pending stores to the inferior... */
 381   CLEAR_DEFERRED_STORES;
 382 #endif
 383
 384   select_frame ((FRAME) 0, -1);
 385   reopen_exec_file ();
 386   if (target_has_stack)
 387     set_current_frame ( create_new_frame (read_register (FP_REGNUM),
 388                                           read_pc ()));
 389   else
 390     set_current_frame (0);
 391   /* It is confusing to the user for ignore counts to stick around
 392      from previous runs of the inferior.  So clear them.  */
 393   breakpoint_clear_ignore_counts ();
 394 }
 395
 396 void
 397 child_mourn_inferior ()
 398 {
 399   unpush_target (&child_ops);
 400   generic_mourn_inferior ();
 401 }
 402 \f
 403 #if 0
 404 /* This function is just for testing, and on some systems (Sony NewsOS
 405    3.2) <sys/user.h> also includes <sys/time.h> which leads to errors
 406    (since on this system at least sys/time.h is not protected against
 407    multiple inclusion).  */
 408 /* ARGSUSED */
 409 static void
 410 try_writing_regs_command (arg, from_tty)
 411      char *arg;
 412      int from_tty;
 413 {
 414   register int i;
 415   register int value;
 416
 417   if (inferior_pid == 0)
 418     error ("There is no inferior process now.");
 419
 420   /* A Sun 3/50 or 3/60 (at least) running SunOS 4.0.3 will have a
 421      kernel panic if we try to write past the end of the user area.
 422      Presumably Sun will fix this bug (it has been reported), but it
 423      is tacky to crash the system, so at least on SunOS4 we need to
 424      stop writing when we hit the end of the user area.  */
 425   for (i = 0; i < sizeof (struct user); i += 2)
 426     {
 427       QUIT;
 428       errno = 0;
 429       value = call_ptrace (3, inferior_pid, i, 0);
 430       call_ptrace (6, inferior_pid, i, value);
 431       if (errno == 0)
 432         {
 433           printf (" Succeeded with address 0x%x; value 0x%x (%d).\n",
 434                   i, value, value);
 435         }
 436       else if ((i & 0377) == 0)
 437         printf (" Failed at 0x%x.\n", i);
 438     }
 439 }
 440 #endif
 441 \f
 442 void
 443 _initialize_inflow ()
 444 {
 445   add_info ("terminal", term_info,
 446            "Print inferior's saved terminal status.");
 447
 448 #if 0
 449   add_com ("try-writing-regs", class_obscure, try_writing_regs_command,
 450            "Try writing all locations in inferior's system block.\n\
 451 Report which ones can be written.");
 452 #endif
 453
 454   add_com ("kill", class_run, kill_command,
 455            "Kill execution of program being debugged.");
 456
 457   inferior_pid = 0;
 458
 459   ioctl (0, TIOCGETP, &sg_ours);
 460   fcntl (0, F_GETFL, tflags_ours);
 461
 462 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 463   ioctl (0, TIOCGETC, &tc_ours);
 464 #endif
 465 #ifdef TIOCGLTC
 466   ioctl (0, TIOCGLTC, &ltc_ours);
 467 #endif
 468 #ifdef TIOCLGET
 469   ioctl (0, TIOCLGET, &lmode_ours);
 470 #endif
 471
 472 #ifdef TIOCGPGRP
 473   ioctl (0, TIOCGPGRP, &pgrp_ours);
 474 #endif /* TIOCGPGRP */
 475
 476   terminal_is_ours = 1;
 477 }
 478