gdb/inflow.c

   1 /* Low level interface to ptrace, for GDB when running under Unix.
   2    Copyright 1986, 1987, 1989, 1991, 1992 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 <signal.h>
  39
  40 extern char *strerror();                /* strings corresponding to errno */
  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 /* Does GDB have a terminal (on stdin)?  */
  53 int gdb_has_a_terminal;
  54
  55 static TERMINAL sg_inferior;
  56 static TERMINAL sg_ours;
  57
  58 static int tflags_inferior;
  59 static int tflags_ours;
  60
  61 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
  62 static struct tchars tc_inferior;
  63 static struct tchars tc_ours;
  64 #endif
  65
  66 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
  67 static struct ltchars ltc_inferior;
  68 static struct ltchars ltc_ours;
  69 #endif
  70
  71 #ifdef TIOCLGET
  72 static int lmode_inferior;
  73 static int lmode_ours;
  74 #endif
  75
  76 #ifdef TIOCGPGRP
  77 # ifdef SHORT_PGRP
  78 static short pgrp_inferior;
  79 static short pgrp_ours;
  80 # else /* not def SHORT_PGRP */
  81 static int pgrp_inferior;
  82 static int pgrp_ours;
  83 # endif /* not def SHORT_PGRP */
  84 #else /* not def TIOCGPGRP */
  85 static void (*sigint_ours) ();
  86 static void (*sigquit_ours) ();
  87 #endif /* TIOCGPGRP */
  88
  89 /* The name of the tty (from the `tty' command) that we gave to the inferior
  90    when it was last started.  */
  91
  92 static char *inferior_thisrun_terminal;
  93
  94 /* Nonzero if our terminal settings are in effect.
  95    Zero if the inferior's settings are in effect.  */
  96
  97 static int terminal_is_ours;
  98
  99 /* Macro for printing errors from ioctl operations */
 100
 101 #define OOPSY(what)     \
 102   if (result == -1)     \
 103     fprintf(stderr, "[%s failed in terminal_inferior: %s]\n", \
 104             what, strerror (errno))
 105
 106 static void terminal_ours_1 ();
 107
 108 /* Initialize the terminal settings we record for the inferior,
 109    before we actually run the inferior.  */
 110
 111 void
 112 terminal_init_inferior ()
 113 {
 114   sg_inferior = sg_ours;
 115   tflags_inferior = tflags_ours;
 116
 117 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 118   tc_inferior = tc_ours;
 119 #endif
 120
 121 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 122   ltc_inferior = ltc_ours;
 123 #endif
 124
 125 #ifdef TIOCLGET
 126   lmode_inferior = lmode_ours;
 127 #endif
 128
 129 #ifdef TIOCGPGRP
 130   pgrp_inferior = inferior_pid;
 131 #endif /* TIOCGPGRP */
 132
 133   terminal_is_ours = 1;
 134 }
 135
 136 /* Put the inferior's terminal settings into effect.
 137    This is preparation for starting or resuming the inferior.  */
 138
 139 void
 140 terminal_inferior ()
 141 {
 142   int result;
 143
 144   if (gdb_has_a_terminal && terminal_is_ours && inferior_thisrun_terminal == 0)
 145     {
 146       result = fcntl (0, F_SETFL, tflags_inferior);
 147       result = fcntl (0, F_SETFL, tflags_inferior);
 148       OOPSY ("fcntl F_SETFL");
 149       result = ioctl (0, TIOCSETN, &sg_inferior);
 150       OOPSY ("ioctl TIOCSETN");
 151
 152 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 153       result = ioctl (0, TIOCSETC, &tc_inferior);
 154       OOPSY ("ioctl TIOCSETC");
 155 #endif
 156 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 157       result = ioctl (0, TIOCSLTC, &ltc_inferior);
 158       OOPSY ("ioctl TIOCSLTC");
 159 #endif
 160 #ifdef TIOCLGET
 161       result = ioctl (0, TIOCLSET, &lmode_inferior);
 162       OOPSY ("ioctl TIOCLSET");
 163 #endif
 164
 165 #ifdef TIOCGPGRP
 166       result = ioctl (0, TIOCSPGRP, &pgrp_inferior);
 167       /* If we attached to the process, we might or might not be sharing
 168          a terminal.  Avoid printing error msg if we are unable to set our
 169          terminal's process group to his process group ID.  */
 170       if (!attach_flag) {
 171         OOPSY ("ioctl TIOCSPGRP");
 172       }
 173 #else
 174       sigint_ours = (void (*) ()) signal (SIGINT, SIG_IGN);
 175       sigquit_ours = (void (*) ()) signal (SIGQUIT, SIG_IGN);
 176 #endif /* TIOCGPGRP */
 177     }
 178   terminal_is_ours = 0;
 179 }
 180
 181 /* Put some of our terminal settings into effect,
 182    enough to get proper results from our output,
 183    but do not change into or out of RAW mode
 184    so that no input is discarded.
 185
 186    After doing this, either terminal_ours or terminal_inferior
 187    should be called to get back to a normal state of affairs.  */
 188
 189 void
 190 terminal_ours_for_output ()
 191 {
 192   terminal_ours_1 (1);
 193 }
 194
 195 /* Put our terminal settings into effect.
 196    First record the inferior's terminal settings
 197    so they can be restored properly later.  */
 198
 199 void
 200 terminal_ours ()
 201 {
 202   terminal_ours_1 (0);
 203 }
 204
 205 static void
 206 terminal_ours_1 (output_only)
 207      int output_only;
 208 {
 209   int result;
 210 #ifdef TIOCGPGRP
 211   /* Ignore this signal since it will happen when we try to set the pgrp.  */
 212   void (*osigttou) ();
 213 #endif /* TIOCGPGRP */
 214
 215   /* Checking inferior_thisrun_terminal is necessary so that
 216      if GDB is running in the background, it won't block trying
 217      to do the ioctl()'s below.  Checking gdb_has_a_terminal
 218      avoids attempting all the ioctl's when running in batch.  */
 219   if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal == 0)
 220     return;
 221
 222   if (!terminal_is_ours)
 223     {
 224       terminal_is_ours = 1;
 225
 226 #ifdef TIOCGPGRP
 227       osigttou = (void (*) ()) signal (SIGTTOU, SIG_IGN);
 228
 229       result = ioctl (0, TIOCGPGRP, &pgrp_inferior);
 230       result = ioctl (0, TIOCSPGRP, &pgrp_ours);
 231
 232       signal (SIGTTOU, osigttou);
 233 #else
 234       signal (SIGINT, sigint_ours);
 235       signal (SIGQUIT, sigquit_ours);
 236 #endif /* TIOCGPGRP */
 237
 238       tflags_inferior = fcntl (0, F_GETFL, 0);
 239       result = ioctl (0, TIOCGETP, &sg_inferior);
 240
 241 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 242       result = ioctl (0, TIOCGETC, &tc_inferior);
 243 #endif
 244 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 245       result = ioctl (0, TIOCGLTC, &ltc_inferior);
 246 #endif
 247 #ifdef TIOCLGET
 248       result = ioctl (0, TIOCLGET, &lmode_inferior);
 249 #endif
 250     }
 251
 252 #ifdef HAVE_TERMIO
 253   sg_ours.c_lflag |= ICANON;
 254   if (output_only && !(sg_inferior.c_lflag & ICANON))
 255     sg_ours.c_lflag &= ~ICANON;
 256 #else /* not HAVE_TERMIO */
 257   sg_ours.sg_flags &= ~RAW & ~CBREAK;
 258   if (output_only)
 259     sg_ours.sg_flags |= (RAW | CBREAK) & sg_inferior.sg_flags;
 260 #endif /* not HAVE_TERMIO */
 261
 262   result = fcntl (0, F_SETFL, tflags_ours);
 263   result = fcntl (0, F_SETFL, tflags_ours);
 264   result = ioctl (0, TIOCSETN, &sg_ours);
 265
 266 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 267   result = ioctl (0, TIOCSETC, &tc_ours);
 268 #endif
 269 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 270   result = ioctl (0, TIOCSLTC, &ltc_ours);
 271 #endif
 272 #ifdef TIOCLGET
 273   result = ioctl (0, TIOCLSET, &lmode_ours);
 274 #endif
 275
 276 #ifdef HAVE_TERMIO
 277   sg_ours.c_lflag |= ICANON;
 278 #else /* not HAVE_TERMIO */
 279   sg_ours.sg_flags &= ~RAW & ~CBREAK;
 280 #endif /* not HAVE_TERMIO */
 281 }
 282
 283 /* ARGSUSED */
 284 void
 285 term_info (arg, from_tty)
 286      char *arg;
 287      int from_tty;
 288 {
 289   target_terminal_info (arg, from_tty);
 290 }
 291
 292 /* ARGSUSED */
 293 void
 294 child_terminal_info (args, from_tty)
 295      char *args;
 296      int from_tty;
 297 {
 298   register int i;
 299
 300   if (!gdb_has_a_terminal) {
 301     printf_filtered ("This GDB does not control a terminal.\n");
 302     return;
 303   }
 304
 305 #ifdef TIOCGPGRP
 306   printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
 307
 308   printf_filtered ("owner pgrp = %d, fcntl flags = 0x%x.\n",
 309           pgrp_inferior, tflags_inferior);
 310 #endif /* TIOCGPGRP */
 311
 312 #ifdef HAVE_TERMIO
 313
 314   printf_filtered ("c_iflag = 0x%x, c_oflag = 0x%x,\n",
 315           sg_inferior.c_iflag, sg_inferior.c_oflag);
 316   printf_filtered ("c_cflag = 0x%x, c_lflag = 0x%x, c_line = 0x%x.\n",
 317           sg_inferior.c_cflag, sg_inferior.c_lflag, sg_inferior.c_line);
 318   printf_filtered ("c_cc: ");
 319   for (i = 0; (i < NCC); i += 1)
 320     printf_filtered ("0x%x ", sg_inferior.c_cc[i]);
 321   printf_filtered ("\n");
 322
 323 #else /* not HAVE_TERMIO */
 324
 325   printf_filtered ("sgttyb.sg_flags = 0x%x.\n", sg_inferior.sg_flags);
 326
 327 #endif /* not HAVE_TERMIO */
 328
 329 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 330   printf_filtered ("tchars: ");
 331   for (i = 0; i < (int)sizeof (struct tchars); i++)
 332     printf_filtered ("0x%x ", ((unsigned char *)&tc_inferior)[i]);
 333   printf_filtered ("\n");
 334 #endif
 335
 336 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 337   printf_filtered ("ltchars: ");
 338   for (i = 0; i < (int)sizeof (struct ltchars); i++)
 339     printf_filtered ("0x%x ", ((unsigned char *)&ltc_inferior)[i]);
 340   printf_filtered ("\n");
 341 #endif
 342
 343 #ifdef TIOCLGET
 344   printf_filtered ("lmode:  0x%x\n", lmode_inferior);
 345 #endif
 346 }
 347 \f
 348 /* NEW_TTY_PREFORK is called before forking a new child process,
 349    so we can record the state of ttys in the child to be formed.
 350    TTYNAME is null if we are to share the terminal with gdb;
 351    or points to a string containing the name of the desired tty.
 352
 353    NEW_TTY is called in new child processes under Unix, which will
 354    become debugger target processes.  This actually switches to
 355    the terminal specified in the NEW_TTY_PREFORK call.  */
 356
 357 void
 358 new_tty_prefork (ttyname)
 359      char *ttyname;
 360 {
 361   /* Save the name for later, for determining whether we and the child
 362      are sharing a tty.  */
 363   inferior_thisrun_terminal = ttyname;
 364 }
 365
 366 void
 367 new_tty ()
 368 {
 369   register int tty;
 370
 371   if (inferior_thisrun_terminal == 0)
 372     return;
 373
 374 #ifdef TIOCNOTTY
 375   /* Disconnect the child process from our controlling terminal.  */
 376   tty = open("/dev/tty", O_RDWR);
 377   if (tty > 0)
 378     {
 379       ioctl(tty, TIOCNOTTY, 0);
 380       close(tty);
 381     }
 382 #endif
 383
 384   /* Now open the specified new terminal.  */
 385
 386 #ifdef USE_O_NOCTTY
 387   tty = open(inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
 388 #else
 389   tty = open(inferior_thisrun_terminal, O_RDWR);
 390 #endif
 391   if (tty == -1)
 392     {
 393       print_sys_errmsg (inferior_thisrun_terminal, errno);
 394       _exit(1);
 395     }
 396
 397   /* Avoid use of dup2; doesn't exist on all systems.  */
 398   if (tty != 0)
 399     { close (0); dup (tty); }
 400   if (tty != 1)
 401     { close (1); dup (tty); }
 402   if (tty != 2)
 403     { close (2); dup (tty); }
 404   if (tty > 2)
 405     close(tty);
 406 }
 407 \f
 408 /* Kill the inferior process.  Make us have no inferior.  */
 409
 410 /* ARGSUSED */
 411 static void
 412 kill_command (arg, from_tty)
 413      char *arg;
 414      int from_tty;
 415 {
 416   if (inferior_pid == 0)
 417     error ("The program is not being run.");
 418   if (!query ("Kill the inferior process? "))
 419     error ("Not confirmed.");
 420   target_kill ();
 421
 422   /* Killing off the inferior can leave us with a core file.  If so,
 423      print the state we are left in.  */
 424   if (target_has_stack) {
 425     printf_filtered ("In %s,\n", current_target->to_longname);
 426     if (selected_frame == NULL)
 427       fputs_filtered ("No selected stack frame.\n", stdout);
 428     else
 429       print_stack_frame (selected_frame, selected_frame_level, 1);
 430   }
 431 }
 432
 433 /* The inferior process has died.  Long live the inferior!  */
 434
 435 void
 436 generic_mourn_inferior ()
 437 {
 438   inferior_pid = 0;
 439   attach_flag = 0;
 440   mark_breakpoints_out ();
 441   registers_changed ();
 442
 443 #ifdef CLEAR_DEFERRED_STORES
 444   /* Delete any pending stores to the inferior... */
 445   CLEAR_DEFERRED_STORES;
 446 #endif
 447
 448   reopen_exec_file ();
 449   if (target_has_stack) {
 450     set_current_frame ( create_new_frame (read_register (FP_REGNUM),
 451                                           read_pc ()));
 452     select_frame (get_current_frame (), 0);
 453   } else {
 454     set_current_frame (0);
 455     select_frame ((FRAME) 0, -1);
 456   }
 457   /* It is confusing to the user for ignore counts to stick around
 458      from previous runs of the inferior.  So clear them.  */
 459   breakpoint_clear_ignore_counts ();
 460 }
 461
 462 void
 463 child_mourn_inferior ()
 464 {
 465   unpush_target (&child_ops);
 466   generic_mourn_inferior ();
 467 }
 468 \f
 469 #if 0
 470 /* This function is just for testing, and on some systems (Sony NewsOS
 471    3.2) <sys/user.h> also includes <sys/time.h> which leads to errors
 472    (since on this system at least sys/time.h is not protected against
 473    multiple inclusion).  */
 474 /* ARGSUSED */
 475 static void
 476 try_writing_regs_command (arg, from_tty)
 477      char *arg;
 478      int from_tty;
 479 {
 480   register int i;
 481   register int value;
 482
 483   if (inferior_pid == 0)
 484     error ("There is no inferior process now.");
 485
 486   /* A Sun 3/50 or 3/60 (at least) running SunOS 4.0.3 will have a
 487      kernel panic if we try to write past the end of the user area.
 488      Presumably Sun will fix this bug (it has been reported), but it
 489      is tacky to crash the system, so at least on SunOS4 we need to
 490      stop writing when we hit the end of the user area.  */
 491   for (i = 0; i < sizeof (struct user); i += 2)
 492     {
 493       QUIT;
 494       errno = 0;
 495       value = call_ptrace (3, inferior_pid, i, 0);
 496       call_ptrace (6, inferior_pid, i, value);
 497       if (errno == 0)
 498         {
 499           printf (" Succeeded with address 0x%x; value 0x%x (%d).\n",
 500                   i, value, value);
 501         }
 502       else if ((i & 0377) == 0)
 503         printf (" Failed at 0x%x.\n", i);
 504     }
 505 }
 506 #endif
 507 \f
 508 void
 509 _initialize_inflow ()
 510 {
 511   int result;
 512
 513   add_info ("terminal", term_info,
 514            "Print inferior's saved terminal status.");
 515
 516 #if 0
 517   add_com ("try-writing-regs", class_obscure, try_writing_regs_command,
 518            "Try writing all locations in inferior's system block.\n\
 519 Report which ones can be written.");
 520 #endif
 521
 522   add_com ("kill", class_run, kill_command,
 523            "Kill execution of program being debugged.");
 524
 525   inferior_pid = 0;
 526
 527   /* Get all the current tty settings (including whether we have a tty at
 528      all!).  */
 529
 530   tflags_ours = fcntl (0, F_GETFL, 0);
 531   OOPSY ("fcntl F_GETFL");              /* Should always work */
 532
 533   result = ioctl (0, TIOCGETP, &sg_ours);
 534   if (result == 0) {
 535     gdb_has_a_terminal = 1;
 536     /* Get the rest of the tty settings, then... */
 537 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 538     ioctl (0, TIOCGETC, &tc_ours);
 539 #endif
 540 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 541     ioctl (0, TIOCGLTC, &ltc_ours);
 542 #endif
 543 #ifdef TIOCLGET
 544     ioctl (0, TIOCLGET, &lmode_ours);
 545 #endif
 546 #ifdef TIOCGPGRP
 547     ioctl (0, TIOCGPGRP, &pgrp_ours);
 548 #endif /* TIOCGPGRP */
 549   } else {
 550     gdb_has_a_terminal = 0;
 551   }
 552
 553   terminal_is_ours = 1;
 554 }