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 char *strerror();                /* strings corresponding to errno */
  42
  43 extern struct target_ops child_ops;
  44
  45 /* Nonzero if we are debugging an attached outside process
  46    rather than an inferior.  */
  47
  48 int attach_flag;
  49
  50 \f
  51 /* Record terminal status separately for debugger and inferior.  */
  52
  53 /* Does GDB have a terminal (on stdin)?  */
  54 int gdb_has_a_terminal;
  55
  56 static TERMINAL sg_inferior;
  57 static TERMINAL sg_ours;
  58
  59 static int tflags_inferior;
  60 static int tflags_ours;
  61
  62 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
  63 static struct tchars tc_inferior;
  64 static struct tchars tc_ours;
  65 #endif
  66
  67 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
  68 static struct ltchars ltc_inferior;
  69 static struct ltchars ltc_ours;
  70 #endif
  71
  72 #ifdef TIOCLGET
  73 static int lmode_inferior;
  74 static int lmode_ours;
  75 #endif
  76
  77 #ifdef TIOCGPGRP
  78 # ifdef SHORT_PGRP
  79 static short pgrp_inferior;
  80 static short pgrp_ours;
  81 # else
  82 static int pgrp_inferior;
  83 static int pgrp_ours;
  84 # endif
  85 #else
  86 static void (*sigint_ours) ();
  87 static void (*sigquit_ours) ();
  88 #endif /* TIOCGPGRP */
  89
  90 /* The name of the tty (from the `tty' command) that we gave to the inferior
  91    when it was last started.  */
  92
  93 static char *inferior_thisrun_terminal;
  94
  95 /* Nonzero if our terminal settings are in effect.
  96    Zero if the inferior's settings are in effect.  */
  97
  98 static int terminal_is_ours;
  99
 100 /* Macro for printing errors from ioctl operations */
 101
 102 #define OOPSY(what)     \
 103   if (result == -1)     \
 104     fprintf(stderr, "[%s failed in terminal_inferior: %s]\n", \
 105             what, strerror (errno))
 106
 107 static void terminal_ours_1 ();
 108
 109 /* Initialize the terminal settings we record for the inferior,
 110    before we actually run the inferior.  */
 111
 112 void
 113 terminal_init_inferior ()
 114 {
 115   sg_inferior = sg_ours;
 116   tflags_inferior = tflags_ours;
 117
 118 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 119   tc_inferior = tc_ours;
 120 #endif
 121
 122 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 123   ltc_inferior = ltc_ours;
 124 #endif
 125
 126 #ifdef TIOCLGET
 127   lmode_inferior = lmode_ours;
 128 #endif
 129
 130 #ifdef TIOCGPGRP
 131   pgrp_inferior = inferior_pid;
 132 #endif /* TIOCGPGRP */
 133
 134   terminal_is_ours = 1;
 135 }
 136
 137 /* Put the inferior's terminal settings into effect.
 138    This is preparation for starting or resuming the inferior.  */
 139
 140 void
 141 terminal_inferior ()
 142 {
 143   int result;
 144
 145   if (gdb_has_a_terminal && terminal_is_ours && inferior_thisrun_terminal == 0)
 146     {
 147       result = fcntl (0, F_SETFL, tflags_inferior);
 148       result = fcntl (0, F_SETFL, tflags_inferior);
 149       OOPSY ("fcntl F_SETFL");
 150       result = ioctl (0, TIOCSETN, &sg_inferior);
 151       OOPSY ("ioctl TIOCSETN");
 152
 153 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 154       result = ioctl (0, TIOCSETC, &tc_inferior);
 155       OOPSY ("ioctl TIOCSETC");
 156 #endif
 157 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 158       result = ioctl (0, TIOCSLTC, &ltc_inferior);
 159       OOPSY ("ioctl TIOCSLTC");
 160 #endif
 161 #ifdef TIOCLGET
 162       result = ioctl (0, TIOCLSET, &lmode_inferior);
 163       OOPSY ("ioctl TIOCLSET");
 164 #endif
 165
 166 #ifdef TIOCGPGRP
 167       result = ioctl (0, TIOCSPGRP, &pgrp_inferior);
 168       OOPSY ("ioctl TIOCSPGRP");
 169 #else
 170       sigint_ours = (void (*) ()) signal (SIGINT, SIG_IGN);
 171       sigquit_ours = (void (*) ()) signal (SIGQUIT, SIG_IGN);
 172 #endif /* TIOCGPGRP */
 173     }
 174   terminal_is_ours = 0;
 175 }
 176
 177 /* Put some of our terminal settings into effect,
 178    enough to get proper results from our output,
 179    but do not change into or out of RAW mode
 180    so that no input is discarded.
 181
 182    After doing this, either terminal_ours or terminal_inferior
 183    should be called to get back to a normal state of affairs.  */
 184
 185 void
 186 terminal_ours_for_output ()
 187 {
 188   terminal_ours_1 (1);
 189 }
 190
 191 /* Put our terminal settings into effect.
 192    First record the inferior's terminal settings
 193    so they can be restored properly later.  */
 194
 195 void
 196 terminal_ours ()
 197 {
 198   terminal_ours_1 (0);
 199 }
 200
 201 static void
 202 terminal_ours_1 (output_only)
 203      int output_only;
 204 {
 205   int result;
 206 #ifdef TIOCGPGRP
 207   /* Ignore this signal since it will happen when we try to set the pgrp.  */
 208   void (*osigttou) ();
 209 #endif /* TIOCGPGRP */
 210
 211   /* Checking inferior_thisrun_terminal is necessary so that
 212      if GDB is running in the background, it won't block trying
 213      to do the ioctl()'s below.  Checking gdb_has_a_terminal
 214      avoids attempting all the ioctl's when running in batch.  */
 215   if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal == 0)
 216     return;
 217
 218   if (!terminal_is_ours)
 219     {
 220       terminal_is_ours = 1;
 221
 222 #ifdef TIOCGPGRP
 223       osigttou = (void (*) ()) signal (SIGTTOU, SIG_IGN);
 224
 225       result = ioctl (0, TIOCGPGRP, &pgrp_inferior);
 226       result = ioctl (0, TIOCSPGRP, &pgrp_ours);
 227
 228       signal (SIGTTOU, osigttou);
 229 #else
 230       signal (SIGINT, sigint_ours);
 231       signal (SIGQUIT, sigquit_ours);
 232 #endif /* TIOCGPGRP */
 233
 234       tflags_inferior = fcntl (0, F_GETFL, 0);
 235       result = ioctl (0, TIOCGETP, &sg_inferior);
 236
 237 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 238       result = ioctl (0, TIOCGETC, &tc_inferior);
 239 #endif
 240 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 241       result = ioctl (0, TIOCGLTC, &ltc_inferior);
 242 #endif
 243 #ifdef TIOCLGET
 244       result = ioctl (0, TIOCLGET, &lmode_inferior);
 245 #endif
 246     }
 247
 248 #ifdef HAVE_TERMIO
 249   sg_ours.c_lflag |= ICANON;
 250   if (output_only && !(sg_inferior.c_lflag & ICANON))
 251     sg_ours.c_lflag &= ~ICANON;
 252 #else /* not HAVE_TERMIO */
 253   sg_ours.sg_flags &= ~RAW & ~CBREAK;
 254   if (output_only)
 255     sg_ours.sg_flags |= (RAW | CBREAK) & sg_inferior.sg_flags;
 256 #endif /* not HAVE_TERMIO */
 257
 258   result = fcntl (0, F_SETFL, tflags_ours);
 259   result = fcntl (0, F_SETFL, tflags_ours);
 260   result = ioctl (0, TIOCSETN, &sg_ours);
 261
 262 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 263   result = ioctl (0, TIOCSETC, &tc_ours);
 264 #endif
 265 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 266   result = ioctl (0, TIOCSLTC, &ltc_ours);
 267 #endif
 268 #ifdef TIOCLGET
 269   result = ioctl (0, TIOCLSET, &lmode_ours);
 270 #endif
 271
 272 #ifdef HAVE_TERMIO
 273   sg_ours.c_lflag |= ICANON;
 274 #else /* not HAVE_TERMIO */
 275   sg_ours.sg_flags &= ~RAW & ~CBREAK;
 276 #endif /* not HAVE_TERMIO */
 277 }
 278
 279 /* ARGSUSED */
 280 void
 281 term_info (arg, from_tty)
 282      char *arg;
 283      int from_tty;
 284 {
 285   target_terminal_info (arg, from_tty);
 286 }
 287
 288 /* ARGSUSED */
 289 void
 290 child_terminal_info (args, from_tty)
 291      char *args;
 292      int from_tty;
 293 {
 294   register int i;
 295
 296   if (!gdb_has_a_terminal) {
 297     printf_filtered ("This GDB does not control a terminal.\n");
 298     return;
 299   }
 300
 301   printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
 302
 303   printf_filtered ("owner pgrp = %d, fcntl flags = 0x%x.\n",
 304           pgrp_inferior, tflags_inferior);
 305
 306 #ifdef HAVE_TERMIO
 307
 308   printf_filtered (c_iflag = 0x%x, c_oflag = 0x%x,\n",
 309           sg_inferior.c_iflag, sg_inferior.c_oflag);
 310   printf_filtered ("c_cflag = 0x%x, c_lflag = 0x%x, c_line = 0x%x.\n",
 311           sg_inferior.c_cflag, sg_inferior.c_lflag, sg_inferior.c_line);
 312   printf_filtered ("c_cc: ");
 313   for (i = 0; (i < NCC); i += 1)
 314     printf_filtered ("0x%x ", sg_inferior.c_cc[i]);
 315   printf_filtered ("\n");
 316
 317 #else /* not HAVE_TERMIO */
 318
 319   printf_filtered ("sgttyb.sg_flags = 0x%x.\n", sg_inferior.sg_flags);
 320
 321 #endif /* not HAVE_TERMIO */
 322
 323 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 324   printf_filtered ("tchars: ");
 325   for (i = 0; i < (int)sizeof (struct tchars); i++)
 326     printf_filtered ("0x%x ", ((unsigned char *)&tc_inferior)[i]);
 327   printf_filtered ("\n");
 328 #endif
 329
 330 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 331   printf_filtered ("ltchars: ");
 332   for (i = 0; i < (int)sizeof (struct ltchars); i++)
 333     printf_filtered ("0x%x ", ((unsigned char *)&ltc_inferior)[i]);
 334   printf_filtered ("\n");
 335 #endif
 336
 337 #ifdef TIOCLGET
 338   printf_filtered ("lmode:  0x%x\n", lmode_inferior);
 339 #endif
 340 }
 341 \f
 342 /* NEW_TTY_PREFORK is called before forking a new child process,
 343    so we can record the state of ttys in the child to be formed.
 344    TTYNAME is null if we are to share the terminal with gdb;
 345    or points to a string containing the name of the desired tty.
 346
 347    NEW_TTY is called in new child processes under Unix, which will
 348    become debugger target processes.  This actually switches to
 349    the terminal specified in the NEW_TTY_PREFORK call.  */
 350
 351 void
 352 new_tty_prefork (ttyname)
 353      char *ttyname;
 354 {
 355   /* Save the name for later, for determining whether we and the child
 356      are sharing a tty.  */
 357   inferior_thisrun_terminal = ttyname;
 358 }
 359
 360 void
 361 new_tty ()
 362 {
 363   register int tty;
 364
 365   if (inferior_thisrun_terminal == 0)
 366     return;
 367
 368 #ifdef TIOCNOTTY
 369   /* Disconnect the child process from our controlling terminal.  */
 370   tty = open("/dev/tty", O_RDWR);
 371   if (tty > 0)
 372     {
 373       ioctl(tty, TIOCNOTTY, 0);
 374       close(tty);
 375     }
 376 #endif
 377
 378   /* Now open the specified new terminal.  */
 379
 380 #ifdef USE_O_NOCTTY
 381   tty = open(inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
 382 #else
 383   tty = open(inferior_thisrun_terminal, O_RDWR);
 384 #endif
 385   if (tty == -1)
 386     {
 387       print_sys_errmsg (inferior_thisrun_terminal, errno);
 388       _exit(1);
 389     }
 390
 391   /* Avoid use of dup2; doesn't exist on all systems.  */
 392   if (tty != 0)
 393     { close (0); dup (tty); }
 394   if (tty != 1)
 395     { close (1); dup (tty); }
 396   if (tty != 2)
 397     { close (2); dup (tty); }
 398   if (tty > 2)
 399     close(tty);
 400 }
 401 \f
 402 /* Kill the inferior process.  Make us have no inferior.  */
 403
 404 /* ARGSUSED */
 405 static void
 406 kill_command (arg, from_tty)
 407      char *arg;
 408      int from_tty;
 409 {
 410   if (inferior_pid == 0)
 411     error ("The program is not being run.");
 412   if (!query ("Kill the inferior process? "))
 413     error ("Not confirmed.");
 414   target_kill (arg, from_tty);
 415
 416   /* Killing off the inferior can leave us with a core file.  If so,
 417      print the state we are left in.  */
 418   if (target_has_stack) {
 419     printf_filtered ("In %s,\n", current_target->to_longname);
 420     if (selected_frame == NULL)
 421       fputs_filtered ("No selected stack frame.\n", stdout);
 422     else
 423       print_stack_frame (selected_frame, selected_frame_level, 1);
 424   }
 425 }
 426
 427 /* The inferior process has died.  Long live the inferior!  */
 428
 429 void
 430 generic_mourn_inferior ()
 431 {
 432   inferior_pid = 0;
 433   attach_flag = 0;
 434   mark_breakpoints_out ();
 435   registers_changed ();
 436
 437 #ifdef CLEAR_DEFERRED_STORES
 438   /* Delete any pending stores to the inferior... */
 439   CLEAR_DEFERRED_STORES;
 440 #endif
 441
 442   reopen_exec_file ();
 443   if (target_has_stack) {
 444     set_current_frame ( create_new_frame (read_register (FP_REGNUM),
 445                                           read_pc ()));
 446     select_frame (get_current_frame (), 0);
 447   } else {
 448     set_current_frame (0);
 449     select_frame ((FRAME) 0, -1);
 450   }
 451   /* It is confusing to the user for ignore counts to stick around
 452      from previous runs of the inferior.  So clear them.  */
 453   breakpoint_clear_ignore_counts ();
 454 }
 455
 456 void
 457 child_mourn_inferior ()
 458 {
 459   unpush_target (&child_ops);
 460   generic_mourn_inferior ();
 461 }
 462 \f
 463 #if 0
 464 /* This function is just for testing, and on some systems (Sony NewsOS
 465    3.2) <sys/user.h> also includes <sys/time.h> which leads to errors
 466    (since on this system at least sys/time.h is not protected against
 467    multiple inclusion).  */
 468 /* ARGSUSED */
 469 static void
 470 try_writing_regs_command (arg, from_tty)
 471      char *arg;
 472      int from_tty;
 473 {
 474   register int i;
 475   register int value;
 476
 477   if (inferior_pid == 0)
 478     error ("There is no inferior process now.");
 479
 480   /* A Sun 3/50 or 3/60 (at least) running SunOS 4.0.3 will have a
 481      kernel panic if we try to write past the end of the user area.
 482      Presumably Sun will fix this bug (it has been reported), but it
 483      is tacky to crash the system, so at least on SunOS4 we need to
 484      stop writing when we hit the end of the user area.  */
 485   for (i = 0; i < sizeof (struct user); i += 2)
 486     {
 487       QUIT;
 488       errno = 0;
 489       value = call_ptrace (3, inferior_pid, i, 0);
 490       call_ptrace (6, inferior_pid, i, value);
 491       if (errno == 0)
 492         {
 493           printf (" Succeeded with address 0x%x; value 0x%x (%d).\n",
 494                   i, value, value);
 495         }
 496       else if ((i & 0377) == 0)
 497         printf (" Failed at 0x%x.\n", i);
 498     }
 499 }
 500 #endif
 501 \f
 502 void
 503 _initialize_inflow ()
 504 {
 505   int result;
 506
 507   add_info ("terminal", term_info,
 508            "Print inferior's saved terminal status.");
 509
 510 #if 0
 511   add_com ("try-writing-regs", class_obscure, try_writing_regs_command,
 512            "Try writing all locations in inferior's system block.\n\
 513 Report which ones can be written.");
 514 #endif
 515
 516   add_com ("kill", class_run, kill_command,
 517            "Kill execution of program being debugged.");
 518
 519   inferior_pid = 0;
 520
 521   /* Get all the current tty settings (including whether we have a tty at
 522      all!).  */
 523
 524   tflags_ours = fcntl (0, F_GETFL, 0);
 525   OOPSY ("fcntl F_GETFL");              /* Should always work */
 526
 527   result = ioctl (0, TIOCGETP, &sg_ours);
 528   if (result == 0) {
 529     gdb_has_a_terminal = 1;
 530     /* Get the rest of the tty settings, then... */
 531 #if defined(TIOCGETC) && !defined(TIOCGETC_BROKEN)
 532     ioctl (0, TIOCGETC, &tc_ours);
 533 #endif
 534 #if defined(TIOCGLTC) && !defined(TIOCGLTC_BROKEN)
 535     ioctl (0, TIOCGLTC, &ltc_ours);
 536 #endif
 537 #ifdef TIOCLGET
 538     ioctl (0, TIOCLGET, &lmode_ours);
 539 #endif
 540 #ifdef TIOCGPGRP
 541     ioctl (0, TIOCGPGRP, &pgrp_ours);
 542 #endif /* TIOCGPGRP */
 543   } else {
 544     gdb_has_a_terminal = 0;
 545   }
 546
 547   terminal_is_ours = 1;
 548 }