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 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 2 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, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include <stdio.h>
  21 #include "defs.h"
  22 #include "frame.h"
  23 #include "inferior.h"
  24 #include "command.h"
  25 #include "signals.h"
  26 #include "terminal.h"
  27 #include "target.h"
  28
  29 #ifdef USG
  30 #include <sys/types.h>
  31 #endif
  32
  33 /* Some USG-esque systems (some of which are BSD-esque enough so that USG
  34    is not defined) want this header, and it won't do any harm.  */
  35 #include <fcntl.h>
  36
  37 #include <sys/param.h>
  38 #include <sys/dir.h>
  39 #include <signal.h>
  40
  41 extern struct target_ops child_ops;
  42
  43 /* Nonzero if we are debugging an attached outside process
  44    rather than an inferior.  */
  45
  46 int attach_flag;
  47
  48 \f
  49 /* Record terminal status separately for debugger and inferior.  */
  50
  51 static TERMINAL sg_inferior;
  52 static TERMINAL sg_ours;
  53
  54 static int tflags_inferior;
  55 static int tflags_ours;
  56
  57 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
  58 static struct tchars tc_inferior;
  59 static struct tchars tc_ours;
  60 #endif
  61
  62 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
  63 static struct ltchars ltc_inferior;
  64 static struct ltchars ltc_ours;
  65 #endif
  66
  67 #ifdef TIOCLGET
  68 static int lmode_inferior;
  69 static int lmode_ours;
  70 #endif
  71
  72 #ifdef TIOCGPGRP
  73 # ifdef SHORT_PGRP
  74 static short pgrp_inferior;
  75 static short pgrp_ours;
  76 # else
  77 static int pgrp_inferior;
  78 static int pgrp_ours;
  79 # endif
  80 #else
  81 static void (*sigint_ours) ();
  82 static void (*sigquit_ours) ();
  83 #endif /* TIOCGPGRP */
  84
  85 /* Copy of inferior_io_terminal when inferior was last started.  */
  86 static char *inferior_thisrun_terminal;
  87
  88 static void terminal_ours_1 ();
  89
  90 /* Nonzero if our terminal settings are in effect.
  91    Zero if the inferior's settings are in effect.  */
  92 static int terminal_is_ours;
  93
  94 /* Initialize the terminal settings we record for the inferior,
  95    before we actually run the inferior.  */
  96
  97 void
  98 terminal_init_inferior ()
  99 {
 100   sg_inferior = sg_ours;
 101   tflags_inferior = tflags_ours;
 102
 103 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 104   tc_inferior = tc_ours;
 105 #endif
 106
 107 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 108   ltc_inferior = ltc_ours;
 109 #endif
 110
 111 #ifdef TIOCLGET
 112   lmode_inferior = lmode_ours;
 113 #endif
 114
 115 #ifdef TIOCGPGRP
 116   pgrp_inferior = inferior_pid;
 117 #endif /* TIOCGPGRP */
 118
 119   terminal_is_ours = 1;
 120 }
 121
 122 /* Put the inferior's terminal settings into effect.
 123    This is preparation for starting or resuming the inferior.  */
 124
 125 void
 126 terminal_inferior ()
 127 {
 128   if (terminal_is_ours && inferior_thisrun_terminal == 0)
 129     {
 130       fcntl (0, F_SETFL, tflags_inferior);
 131       fcntl (0, F_SETFL, tflags_inferior);
 132       ioctl (0, TIOCSETN, &sg_inferior);
 133
 134 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 135       ioctl (0, TIOCSETC, &tc_inferior);
 136 #endif
 137 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 138       ioctl (0, TIOCSLTC, &ltc_inferior);
 139 #endif
 140 #ifdef TIOCLGET
 141       ioctl (0, TIOCLSET, &lmode_inferior);
 142 #endif
 143
 144 #ifdef TIOCGPGRP
 145       ioctl (0, TIOCSPGRP, &pgrp_inferior);
 146 #else
 147       sigint_ours = (void (*) ()) signal (SIGINT, SIG_IGN);
 148       sigquit_ours = (void (*) ()) signal (SIGQUIT, SIG_IGN);
 149 #endif /* TIOCGPGRP */
 150     }
 151   terminal_is_ours = 0;
 152 }
 153
 154 /* Put some of our terminal settings into effect,
 155    enough to get proper results from our output,
 156    but do not change into or out of RAW mode
 157    so that no input is discarded.
 158
 159    After doing this, either terminal_ours or terminal_inferior
 160    should be called to get back to a normal state of affairs.  */
 161
 162 void
 163 terminal_ours_for_output ()
 164 {
 165   terminal_ours_1 (1);
 166 }
 167
 168 /* Put our terminal settings into effect.
 169    First record the inferior's terminal settings
 170    so they can be restored properly later.  */
 171
 172 void
 173 terminal_ours ()
 174 {
 175   terminal_ours_1 (0);
 176 }
 177
 178 static void
 179 terminal_ours_1 (output_only)
 180      int output_only;
 181 {
 182 #ifdef TIOCGPGRP
 183   /* Ignore this signal since it will happen when we try to set the pgrp.  */
 184   void (*osigttou) ();
 185 #endif /* TIOCGPGRP */
 186
 187   /* The check for inferior_thisrun_terminal had been commented out
 188      when the call to ioctl (TIOCNOTTY) was commented out.
 189      Checking inferior_thisrun_terminal is necessary so that
 190      if GDB is running in the background, it won't block trying
 191      to do the ioctl()'s below.  */
 192   if (inferior_thisrun_terminal != 0)
 193     return;
 194
 195   if (!terminal_is_ours)
 196     {
 197       terminal_is_ours = 1;
 198
 199 #ifdef TIOCGPGRP
 200       osigttou = (void (*) ()) signal (SIGTTOU, SIG_IGN);
 201
 202       ioctl (0, TIOCGPGRP, &pgrp_inferior);
 203       ioctl (0, TIOCSPGRP, &pgrp_ours);
 204
 205       signal (SIGTTOU, osigttou);
 206 #else
 207       signal (SIGINT, sigint_ours);
 208       signal (SIGQUIT, sigquit_ours);
 209 #endif /* TIOCGPGRP */
 210
 211       tflags_inferior = fcntl (0, F_GETFL, 0);
 212       ioctl (0, TIOCGETP, &sg_inferior);
 213
 214 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 215       ioctl (0, TIOCGETC, &tc_inferior);
 216 #endif
 217 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 218       ioctl (0, TIOCGLTC, &ltc_inferior);
 219 #endif
 220 #ifdef TIOCLGET
 221       ioctl (0, TIOCLGET, &lmode_inferior);
 222 #endif
 223     }
 224
 225 #ifdef HAVE_TERMIO
 226   sg_ours.c_lflag |= ICANON;
 227   if (output_only && !(sg_inferior.c_lflag & ICANON))
 228     sg_ours.c_lflag &= ~ICANON;
 229 #else /* not HAVE_TERMIO */
 230   sg_ours.sg_flags &= ~RAW & ~CBREAK;
 231   if (output_only)
 232     sg_ours.sg_flags |= (RAW | CBREAK) & sg_inferior.sg_flags;
 233 #endif /* not HAVE_TERMIO */
 234
 235   fcntl (0, F_SETFL, tflags_ours);
 236   fcntl (0, F_SETFL, tflags_ours);
 237   ioctl (0, TIOCSETN, &sg_ours);
 238
 239 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 240   ioctl (0, TIOCSETC, &tc_ours);
 241 #endif
 242 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 243   ioctl (0, TIOCSLTC, &ltc_ours);
 244 #endif
 245 #ifdef TIOCLGET
 246   ioctl (0, TIOCLSET, &lmode_ours);
 247 #endif
 248
 249 #ifdef HAVE_TERMIO
 250   sg_ours.c_lflag |= ICANON;
 251 #else /* not HAVE_TERMIO */
 252   sg_ours.sg_flags &= ~RAW & ~CBREAK;
 253 #endif /* not HAVE_TERMIO */
 254 }
 255
 256 /* ARGSUSED */
 257 void
 258 term_info (arg, from_tty)
 259      char *arg;
 260      int from_tty;
 261 {
 262   target_terminal_info (arg, from_tty);
 263 }
 264
 265 /* ARGSUSED */
 266 void
 267 child_terminal_info (args, from_tty)
 268      char *args;
 269      int from_tty;
 270 {
 271   register int i;
 272
 273   printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
 274
 275 #ifdef HAVE_TERMIO
 276
 277   printf_filtered ("fcntl flags = 0x%x, c_iflag = 0x%x, c_oflag = 0x%x,\n",
 278           tflags_inferior, sg_inferior.c_iflag, sg_inferior.c_oflag);
 279   printf_filtered ("c_cflag = 0x%x, c_lflag = 0x%x, c_line = 0x%x.\n",
 280           sg_inferior.c_cflag, sg_inferior.c_lflag, sg_inferior.c_line);
 281   printf_filtered ("c_cc: ");
 282   for (i = 0; (i < NCC); i += 1)
 283     printf_filtered ("0x%x ", sg_inferior.c_cc[i]);
 284   printf_filtered ("\n");
 285
 286 #else /* not HAVE_TERMIO */
 287
 288   printf_filtered ("fcntl flags = 0x%x, sgttyb.sg_flags = 0x%x, owner pid = %d.\n",
 289           tflags_inferior, sg_inferior.sg_flags, pgrp_inferior);
 290
 291 #endif /* not HAVE_TERMIO */
 292
 293 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 294   printf_filtered ("tchars: ");
 295   for (i = 0; i < (int)sizeof (struct tchars); i++)
 296     printf_filtered ("0x%x ", ((char *)&tc_inferior)[i]);
 297   printf_filtered ("\n");
 298 #endif
 299
 300 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 301   printf_filtered ("ltchars: ");
 302   for (i = 0; i < (int)sizeof (struct ltchars); i++)
 303     printf_filtered ("0x%x ", ((char *)&ltc_inferior)[i]);
 304   printf_filtered ("\n");
 305 #endif
 306
 307 #ifdef TIOCLGET
 308   printf_filtered ("lmode:  0x%x\n", lmode_inferior);
 309 #endif
 310 }
 311 \f
 312 /* NEW_TTY_PREFORK is called before forking a new child process,
 313    so we can record the state of ttys in the child to be formed.
 314    TTYNAME is null if we are to share the terminal with gdb;
 315    or points to a string containing the name of the desired tty.
 316
 317    NEW_TTY is called in new child processes under Unix, which will
 318    become debugger target processes.  This actually switches to
 319    the terminal specified in the NEW_TTY_PREFORK call.  */
 320
 321 void
 322 new_tty_prefork (ttyname)
 323      char *ttyname;
 324 {
 325   /* Save the name for later, for determining whether we and the child
 326      are sharing a tty.  */
 327   inferior_thisrun_terminal = ttyname;
 328 }
 329
 330 void
 331 new_tty ()
 332 {
 333   register int tty;
 334
 335   if (inferior_thisrun_terminal == 0)
 336     return;
 337
 338 #ifdef TIOCNOTTY
 339   /* Disconnect the child process from our controlling terminal.  */
 340   tty = open("/dev/tty", O_RDWR);
 341   if (tty > 0)
 342     {
 343       ioctl(tty, TIOCNOTTY, 0);
 344       close(tty);
 345     }
 346 #endif
 347
 348   /* Now open the specified new terminal.  */
 349
 350 #ifdef USE_O_NOCTTY
 351   tty = open(inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
 352 #else
 353   tty = open(inferior_thisrun_terminal, O_RDWR);
 354 #endif
 355   if (tty == -1)
 356     {
 357       print_sys_errmsg (inferior_thisrun_terminal, errno);
 358       _exit(1);
 359     }
 360
 361   /* Avoid use of dup2; doesn't exist on all systems.  */
 362   if (tty != 0)
 363     { close (0); dup (tty); }
 364   if (tty != 1)
 365     { close (1); dup (tty); }
 366   if (tty != 2)
 367     { close (2); dup (tty); }
 368   if (tty > 2)
 369     close(tty);
 370 }
 371 \f
 372 /* Kill the inferior process.  Make us have no inferior.  */
 373
 374 /* ARGSUSED */
 375 static void
 376 kill_command (arg, from_tty)
 377      char *arg;
 378      int from_tty;
 379 {
 380   if (inferior_pid == 0)
 381     error ("The program is not being run.");
 382   if (!query ("Kill the inferior process? "))
 383     error ("Not confirmed.");
 384   target_kill (arg, from_tty);
 385
 386   /* Killing off the inferior can leave us with a core file.  If so,
 387      print the state we are left in.  */
 388   if (target_has_stack) {
 389     printf_filtered ("In %s,\n", current_target->to_longname);
 390     if (selected_frame == NULL)
 391       fputs_filtered ("No selected stack frame.\n", stdout);
 392     else
 393       print_stack_frame (selected_frame, selected_frame_level, 1);
 394   }
 395 }
 396
 397 /* The inferior process has died.  Long live the inferior!  */
 398
 399 void
 400 generic_mourn_inferior ()
 401 {
 402   inferior_pid = 0;
 403   attach_flag = 0;
 404   mark_breakpoints_out ();
 405   registers_changed ();
 406
 407 #ifdef CLEAR_DEFERRED_STORES
 408   /* Delete any pending stores to the inferior... */
 409   CLEAR_DEFERRED_STORES;
 410 #endif
 411
 412   reopen_exec_file ();
 413   if (target_has_stack) {
 414     set_current_frame ( create_new_frame (read_register (FP_REGNUM),
 415                                           read_pc ()));
 416     select_frame (get_current_frame (), 0);
 417   } else {
 418     set_current_frame (0);
 419     select_frame ((FRAME) 0, -1);
 420   }
 421   /* It is confusing to the user for ignore counts to stick around
 422      from previous runs of the inferior.  So clear them.  */
 423   breakpoint_clear_ignore_counts ();
 424 }
 425
 426 void
 427 child_mourn_inferior ()
 428 {
 429   unpush_target (&child_ops);
 430   generic_mourn_inferior ();
 431 }
 432 \f
 433 #if 0
 434 /* This function is just for testing, and on some systems (Sony NewsOS
 435    3.2) <sys/user.h> also includes <sys/time.h> which leads to errors
 436    (since on this system at least sys/time.h is not protected against
 437    multiple inclusion).  */
 438 /* ARGSUSED */
 439 static void
 440 try_writing_regs_command (arg, from_tty)
 441      char *arg;
 442      int from_tty;
 443 {
 444   register int i;
 445   register int value;
 446
 447   if (inferior_pid == 0)
 448     error ("There is no inferior process now.");
 449
 450   /* A Sun 3/50 or 3/60 (at least) running SunOS 4.0.3 will have a
 451      kernel panic if we try to write past the end of the user area.
 452      Presumably Sun will fix this bug (it has been reported), but it
 453      is tacky to crash the system, so at least on SunOS4 we need to
 454      stop writing when we hit the end of the user area.  */
 455   for (i = 0; i < sizeof (struct user); i += 2)
 456     {
 457       QUIT;
 458       errno = 0;
 459       value = call_ptrace (3, inferior_pid, i, 0);
 460       call_ptrace (6, inferior_pid, i, value);
 461       if (errno == 0)
 462         {
 463           printf (" Succeeded with address 0x%x; value 0x%x (%d).\n",
 464                   i, value, value);
 465         }
 466       else if ((i & 0377) == 0)
 467         printf (" Failed at 0x%x.\n", i);
 468     }
 469 }
 470 #endif
 471 \f
 472 void
 473 _initialize_inflow ()
 474 {
 475   add_info ("terminal", term_info,
 476            "Print inferior's saved terminal status.");
 477
 478 #if 0
 479   add_com ("try-writing-regs", class_obscure, try_writing_regs_command,
 480            "Try writing all locations in inferior's system block.\n\
 481 Report which ones can be written.");
 482 #endif
 483
 484   add_com ("kill", class_run, kill_command,
 485            "Kill execution of program being debugged.");
 486
 487   inferior_pid = 0;
 488
 489   ioctl (0, TIOCGETP, &sg_ours);
 490   tflags_ours = fcntl (0, F_GETFL, 0);
 491
 492 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 493   ioctl (0, TIOCGETC, &tc_ours);
 494 #endif
 495 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 496   ioctl (0, TIOCGLTC, &ltc_ours);
 497 #endif
 498 #ifdef TIOCLGET
 499   ioctl (0, TIOCLGET, &lmode_ours);
 500 #endif
 501
 502 #ifdef TIOCGPGRP
 503   ioctl (0, TIOCGPGRP, &pgrp_ours);
 504 #endif /* TIOCGPGRP */
 505
 506   terminal_is_ours = 1;
 507 }
 508