sim/common/callback.c

   1 /* Remote target callback routines.
   2    Copyright 1995-1997, 2000, 2002-2004, 2007-2012 Free Software
   3    Foundation, Inc.
   4    Contributed by Cygnus Solutions.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 /* This file provides a standard way for targets to talk to the host OS
  22    level.  */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include "cconfig.h"
  26 #endif
  27 #include "config.h"
  28 #include "ansidecl.h"
  29 #include <stdarg.h>
  30 #include <stdio.h>
  31 #ifdef HAVE_STDLIB_H
  32 #include <stdlib.h>
  33 #endif
  34 #ifdef HAVE_STRING_H
  35 #include <string.h>
  36 #else
  37 #ifdef HAVE_STRINGS_H
  38 #include <strings.h>
  39 #endif
  40 #endif
  41 #ifdef HAVE_LIMITS_H
  42 /* For PIPE_BUF.  */
  43 #include <limits.h>
  44 #endif
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <time.h>
  48 #include <sys/types.h>
  49 #include <sys/stat.h>
  50 #include "gdb/callback.h"
  51 #include "targ-vals.h"
  52 /* For xmalloc.  */
  53 #include "libiberty.h"
  54
  55 #ifdef HAVE_UNISTD_H
  56 #include <unistd.h>
  57 #endif
  58
  59 #ifndef PIPE_BUF
  60 #define PIPE_BUF 512
  61 #endif
  62
  63 /* ??? sim_cb_printf should be cb_printf, but until the callback support is
  64    broken out of the simulator directory, these are here to not require
  65    sim-utils.h.  */
  66 void sim_cb_printf PARAMS ((host_callback *, const char *, ...));
  67 void sim_cb_eprintf PARAMS ((host_callback *, const char *, ...));
  68
  69 extern CB_TARGET_DEFS_MAP cb_init_syscall_map[];
  70 extern CB_TARGET_DEFS_MAP cb_init_errno_map[];
  71 extern CB_TARGET_DEFS_MAP cb_init_open_map[];
  72
  73 extern int system PARAMS ((const char *));
  74
  75 static int os_init PARAMS ((host_callback *));
  76 static int os_shutdown PARAMS ((host_callback *));
  77 static int os_unlink PARAMS ((host_callback *, const char *));
  78 static long os_time PARAMS ((host_callback *, long *));
  79 static int os_system PARAMS ((host_callback *, const char *));
  80 static int os_rename PARAMS ((host_callback *, const char *, const char *));
  81 static int os_write_stdout PARAMS ((host_callback *, const char *, int));
  82 static void os_flush_stdout PARAMS ((host_callback *));
  83 static int os_write_stderr PARAMS ((host_callback *, const char *, int));
  84 static void os_flush_stderr PARAMS ((host_callback *));
  85 static int os_write PARAMS ((host_callback *, int, const char *, int));
  86 static int os_read_stdin PARAMS ((host_callback *, char *, int));
  87 static int os_read PARAMS ((host_callback *, int, char *, int));
  88 static int os_open PARAMS ((host_callback *, const char *, int));
  89 static int os_lseek PARAMS ((host_callback *, int, long, int));
  90 static int os_isatty PARAMS ((host_callback *, int));
  91 static int os_get_errno PARAMS ((host_callback *));
  92 static int os_close PARAMS ((host_callback *, int));
  93 static void os_vprintf_filtered PARAMS ((host_callback *, const char *, va_list));
  94 static void os_evprintf_filtered PARAMS ((host_callback *, const char *, va_list));
  95 static void os_error PARAMS ((host_callback *, const char *, ...))
  96 #ifdef __GNUC__
  97   __attribute__ ((__noreturn__))
  98 #endif
  99   ;
 100 static int fdmap PARAMS ((host_callback *, int));
 101 static int fdbad PARAMS ((host_callback *, int));
 102 static int wrap PARAMS ((host_callback *, int));
 103
 104 /* Set the callback copy of errno from what we see now.  */
 105
 106 static int
 107 wrap (p, val)
 108      host_callback *p;
 109      int val;
 110 {
 111   p->last_errno = errno;
 112   return val;
 113 }
 114
 115 /* Make sure the FD provided is ok.  If not, return non-zero
 116    and set errno. */
 117
 118 static int
 119 fdbad (p, fd)
 120      host_callback *p;
 121      int fd;
 122 {
 123   if (fd < 0 || fd > MAX_CALLBACK_FDS || p->fd_buddy[fd] < 0)
 124     {
 125       p->last_errno = EBADF;
 126       return -1;
 127     }
 128   return 0;
 129 }
 130
 131 static int
 132 fdmap (p, fd)
 133      host_callback *p;
 134      int fd;
 135 {
 136   return p->fdmap[fd];
 137 }
 138
 139 static int
 140 os_close (p, fd)
 141      host_callback *p;
 142      int fd;
 143 {
 144   int result;
 145   int i, next;
 146
 147   result = fdbad (p, fd);
 148   if (result)
 149     return result;
 150   /* If this file descripter has one or more buddies (originals /
 151      duplicates from a dup), just remove it from the circular list.  */
 152   for (i = fd; (next = p->fd_buddy[i]) != fd; )
 153     i = next;
 154   if (fd != i)
 155     p->fd_buddy[i] = p->fd_buddy[fd];
 156   else
 157     {
 158       if (p->ispipe[fd])
 159         {
 160           int other = p->ispipe[fd];
 161           int reader, writer;
 162
 163           if (other > 0)
 164             {
 165               /* Closing the read side.  */
 166               reader = fd;
 167               writer = other;
 168             }
 169           else
 170             {
 171               /* Closing the write side.  */
 172               writer = fd;
 173               reader = -other;
 174             }
 175
 176           /* If there was data in the buffer, make a last "now empty"
 177              call, then deallocate data.  */
 178           if (p->pipe_buffer[writer].buffer != NULL)
 179             {
 180               (*p->pipe_empty) (p, reader, writer);
 181               free (p->pipe_buffer[writer].buffer);
 182               p->pipe_buffer[writer].buffer = NULL;
 183             }
 184
 185           /* Clear pipe data for this side.  */
 186           p->pipe_buffer[fd].size = 0;
 187           p->ispipe[fd] = 0;
 188
 189           /* If this was the first close, mark the other side as the
 190              only remaining side.  */
 191           if (fd != abs (other))
 192             p->ispipe[abs (other)] = -other;
 193           p->fd_buddy[fd] = -1;
 194           return 0;
 195         }
 196
 197       result = wrap (p, close (fdmap (p, fd)));
 198     }
 199   p->fd_buddy[fd] = -1;
 200
 201   return result;
 202 }
 203
 204
 205 /* taken from gdb/util.c:notice_quit() - should be in a library */
 206
 207
 208 #if defined(__GO32__) || defined (_MSC_VER)
 209 static int
 210 os_poll_quit (p)
 211      host_callback *p;
 212 {
 213 #if defined(__GO32__)
 214   int kbhit ();
 215   int getkey ();
 216   if (kbhit ())
 217     {
 218       int k = getkey ();
 219       if (k == 1)
 220         {
 221           return 1;
 222         }
 223       else if (k == 2)
 224         {
 225           return 1;
 226         }
 227       else
 228         {
 229           sim_cb_eprintf (p, "CTRL-A to quit, CTRL-B to quit harder\n");
 230         }
 231     }
 232 #endif
 233 #if defined (_MSC_VER)
 234   /* NB - this will not compile! */
 235   int k = win32pollquit ();
 236   if (k == 1)
 237     return 1;
 238   else if (k == 2)
 239     return 1;
 240 #endif
 241   return 0;
 242 }
 243 #else
 244 #define os_poll_quit 0
 245 #endif /* defined(__GO32__) || defined(_MSC_VER) */
 246
 247 static int
 248 os_get_errno (p)
 249      host_callback *p;
 250 {
 251   return cb_host_to_target_errno (p, p->last_errno);
 252 }
 253
 254
 255 static int
 256 os_isatty (p, fd)
 257      host_callback *p;
 258      int fd;
 259 {
 260   int result;
 261
 262   result = fdbad (p, fd);
 263   if (result)
 264     return result;
 265   result = wrap (p, isatty (fdmap (p, fd)));
 266
 267   return result;
 268 }
 269
 270 static int
 271 os_lseek (p, fd, off, way)
 272      host_callback *p;
 273      int fd;
 274      long off;
 275      int way;
 276 {
 277   int result;
 278
 279   result = fdbad (p, fd);
 280   if (result)
 281     return result;
 282   result = wrap (p, lseek (fdmap (p, fd), off, way));
 283   return result;
 284 }
 285
 286 static int
 287 os_open (p, name, flags)
 288      host_callback *p;
 289      const char *name;
 290      int flags;
 291 {
 292   int i;
 293   for (i = 0; i < MAX_CALLBACK_FDS; i++)
 294     {
 295       if (p->fd_buddy[i] < 0)
 296         {
 297           int f = open (name, cb_target_to_host_open (p, flags), 0644);
 298           if (f < 0)
 299             {
 300               p->last_errno = errno;
 301               return f;
 302             }
 303           p->fd_buddy[i] = i;
 304           p->fdmap[i] = f;
 305           return i;
 306         }
 307     }
 308   p->last_errno = EMFILE;
 309   return -1;
 310 }
 311
 312 static int
 313 os_read (p, fd, buf, len)
 314      host_callback *p;
 315      int fd;
 316      char *buf;
 317      int len;
 318 {
 319   int result;
 320
 321   result = fdbad (p, fd);
 322   if (result)
 323     return result;
 324   if (p->ispipe[fd])
 325     {
 326       int writer = p->ispipe[fd];
 327
 328       /* Can't read from the write-end.  */
 329       if (writer < 0)
 330         {
 331           p->last_errno = EBADF;
 332           return -1;
 333         }
 334
 335       /* Nothing to read if nothing is written.  */
 336       if (p->pipe_buffer[writer].size == 0)
 337         return 0;
 338
 339       /* Truncate read request size to buffer size minus what's already
 340          read.  */
 341       if (len > p->pipe_buffer[writer].size - p->pipe_buffer[fd].size)
 342         len = p->pipe_buffer[writer].size - p->pipe_buffer[fd].size;
 343
 344       memcpy (buf, p->pipe_buffer[writer].buffer + p->pipe_buffer[fd].size,
 345               len);
 346
 347       /* Account for what we just read.  */
 348       p->pipe_buffer[fd].size += len;
 349
 350       /* If we've read everything, empty and deallocate the buffer and
 351          signal buffer-empty to client.  (This isn't expected to be a
 352          hot path in the simulator, so we don't hold on to the buffer.)  */
 353       if (p->pipe_buffer[fd].size == p->pipe_buffer[writer].size)
 354         {
 355           free (p->pipe_buffer[writer].buffer);
 356           p->pipe_buffer[writer].buffer = NULL;
 357           p->pipe_buffer[fd].size = 0;
 358           p->pipe_buffer[writer].size = 0;
 359           (*p->pipe_empty) (p, fd, writer);
 360         }
 361
 362       return len;
 363     }
 364
 365   result = wrap (p, read (fdmap (p, fd), buf, len));
 366   return result;
 367 }
 368
 369 static int
 370 os_read_stdin (p, buf, len)
 371      host_callback *p;
 372      char *buf;
 373      int len;
 374 {
 375   return wrap (p, read (0, buf, len));
 376 }
 377
 378 static int
 379 os_write (p, fd, buf, len)
 380      host_callback *p;
 381      int fd;
 382      const char *buf;
 383      int len;
 384 {
 385   int result;
 386   int real_fd;
 387
 388   result = fdbad (p, fd);
 389   if (result)
 390     return result;
 391
 392   if (p->ispipe[fd])
 393     {
 394       int reader = -p->ispipe[fd];
 395
 396       /* Can't write to the read-end.  */
 397       if (reader < 0)
 398         {
 399           p->last_errno = EBADF;
 400           return -1;
 401         }
 402
 403       /* Can't write to pipe with closed read end.
 404          FIXME: We should send a SIGPIPE.  */
 405       if (reader == fd)
 406         {
 407           p->last_errno = EPIPE;
 408           return -1;
 409         }
 410
 411       /* As a sanity-check, we bail out it the buffered contents is much
 412          larger than the size of the buffer on the host.  We don't want
 413          to run out of memory in the simulator due to a target program
 414          bug if we can help it.  Unfortunately, regarding the value that
 415          reaches the simulated program, it's no use returning *less*
 416          than the requested amount, because cb_syscall loops calling
 417          this function until the whole amount is done.  */
 418       if (p->pipe_buffer[fd].size + len > 10 * PIPE_BUF)
 419         {
 420           p->last_errno = EFBIG;
 421           return -1;
 422         }
 423
 424       p->pipe_buffer[fd].buffer
 425         = xrealloc (p->pipe_buffer[fd].buffer, p->pipe_buffer[fd].size + len);
 426       memcpy (p->pipe_buffer[fd].buffer + p->pipe_buffer[fd].size,
 427               buf, len);
 428       p->pipe_buffer[fd].size += len;
 429
 430       (*p->pipe_nonempty) (p, reader, fd);
 431       return len;
 432     }
 433
 434   real_fd = fdmap (p, fd);
 435   switch (real_fd)
 436     {
 437     default:
 438       result = wrap (p, write (real_fd, buf, len));
 439       break;
 440     case 1:
 441       result = p->write_stdout (p, buf, len);
 442       break;
 443     case 2:
 444       result = p->write_stderr (p, buf, len);
 445       break;
 446     }
 447   return result;
 448 }
 449
 450 static int
 451 os_write_stdout (p, buf, len)
 452      host_callback *p ATTRIBUTE_UNUSED;
 453      const char *buf;
 454      int len;
 455 {
 456   return fwrite (buf, 1, len, stdout);
 457 }
 458
 459 static void
 460 os_flush_stdout (p)
 461      host_callback *p ATTRIBUTE_UNUSED;
 462 {
 463   fflush (stdout);
 464 }
 465
 466 static int
 467 os_write_stderr (p, buf, len)
 468      host_callback *p ATTRIBUTE_UNUSED;
 469      const char *buf;
 470      int len;
 471 {
 472   return fwrite (buf, 1, len, stderr);
 473 }
 474
 475 static void
 476 os_flush_stderr (p)
 477      host_callback *p ATTRIBUTE_UNUSED;
 478 {
 479   fflush (stderr);
 480 }
 481
 482 static int
 483 os_rename (p, f1, f2)
 484      host_callback *p;
 485      const char *f1;
 486      const char *f2;
 487 {
 488   return wrap (p, rename (f1, f2));
 489 }
 490
 491
 492 static int
 493 os_system (p, s)
 494      host_callback *p;
 495      const char *s;
 496 {
 497   return wrap (p, system (s));
 498 }
 499
 500 static long
 501 os_time (p, t)
 502      host_callback *p;
 503      long *t;
 504 {
 505   return wrap (p, time (t));
 506 }
 507
 508
 509 static int
 510 os_unlink (p, f1)
 511      host_callback *p;
 512      const char *f1;
 513 {
 514   return wrap (p, unlink (f1));
 515 }
 516
 517 static int
 518 os_stat (p, file, buf)
 519      host_callback *p;
 520      const char *file;
 521      struct stat *buf;
 522 {
 523   /* ??? There is an issue of when to translate to the target layout.
 524      One could do that inside this function, or one could have the
 525      caller do it.  It's more flexible to let the caller do it, though
 526      I'm not sure the flexibility will ever be useful.  */
 527   return wrap (p, stat (file, buf));
 528 }
 529
 530 static int
 531 os_fstat (p, fd, buf)
 532      host_callback *p;
 533      int fd;
 534      struct stat *buf;
 535 {
 536   if (fdbad (p, fd))
 537     return -1;
 538
 539   if (p->ispipe[fd])
 540     {
 541 #if defined (HAVE_STRUCT_STAT_ST_ATIME) || defined (HAVE_STRUCT_STAT_ST_CTIME) || defined (HAVE_STRUCT_STAT_ST_MTIME)
 542       time_t t = (*p->time) (p, NULL);
 543 #endif
 544
 545       /* We have to fake the struct stat contents, since the pipe is
 546          made up in the simulator.  */
 547       memset (buf, 0, sizeof (*buf));
 548
 549 #ifdef HAVE_STRUCT_STAT_ST_MODE
 550       buf->st_mode = S_IFIFO;
 551 #endif
 552
 553       /* If more accurate tracking than current-time is needed (for
 554          example, on GNU/Linux we get accurate numbers), the p->time
 555          callback (which may be something other than os_time) should
 556          happen for each read and write, and we'd need to keep track of
 557          atime, ctime and mtime.  */
 558 #ifdef HAVE_STRUCT_STAT_ST_ATIME
 559       buf->st_atime = t;
 560 #endif
 561 #ifdef HAVE_STRUCT_STAT_ST_CTIME
 562       buf->st_ctime = t;
 563 #endif
 564 #ifdef HAVE_STRUCT_STAT_ST_MTIME
 565       buf->st_mtime = t;
 566 #endif
 567       return 0;
 568     }
 569
 570   /* ??? There is an issue of when to translate to the target layout.
 571      One could do that inside this function, or one could have the
 572      caller do it.  It's more flexible to let the caller do it, though
 573      I'm not sure the flexibility will ever be useful.  */
 574   return wrap (p, fstat (fdmap (p, fd), buf));
 575 }
 576
 577 static int
 578 os_lstat (p, file, buf)
 579      host_callback *p;
 580      const char *file;
 581      struct stat *buf;
 582 {
 583   /* NOTE: hpn/2004-12-12: Same issue here as with os_fstat.  */
 584 #ifdef HAVE_LSTAT
 585   return wrap (p, lstat (file, buf));
 586 #else
 587   return wrap (p, stat (file, buf));
 588 #endif
 589 }
 590
 591 static int
 592 os_ftruncate (p, fd, len)
 593      host_callback *p;
 594      int fd;
 595      long len;
 596 {
 597   int result;
 598
 599   result = fdbad (p, fd);
 600   if (p->ispipe[fd])
 601     {
 602       p->last_errno = EINVAL;
 603       return -1;
 604     }
 605   if (result)
 606     return result;
 607 #ifdef HAVE_FTRUNCATE
 608   result = wrap (p, ftruncate (fdmap (p, fd), len));
 609 #else
 610   p->last_errno = EINVAL;
 611   result = -1;
 612 #endif
 613   return result;
 614 }
 615
 616 static int
 617 os_truncate (p, file, len)
 618      host_callback *p;
 619      const char *file;
 620      long len;
 621 {
 622 #ifdef HAVE_TRUNCATE
 623   return wrap (p, truncate (file, len));
 624 #else
 625   p->last_errno = EINVAL;
 626   return -1;
 627 #endif
 628 }
 629
 630 static int
 631 os_pipe (p, filedes)
 632      host_callback *p;
 633      int *filedes;
 634 {
 635   int i;
 636
 637   /* We deliberately don't use fd 0.  It's probably stdin anyway.  */
 638   for (i = 1; i < MAX_CALLBACK_FDS; i++)
 639     {
 640       int j;
 641
 642       if (p->fd_buddy[i] < 0)
 643         for (j = i + 1; j < MAX_CALLBACK_FDS; j++)
 644           if (p->fd_buddy[j] < 0)
 645             {
 646               /* Found two free fd:s.  Set stat to allocated and mark
 647                  pipeness.  */
 648               p->fd_buddy[i] = i;
 649               p->fd_buddy[j] = j;
 650               p->ispipe[i] = j;
 651               p->ispipe[j] = -i;
 652               filedes[0] = i;
 653               filedes[1] = j;
 654
 655               /* Poison the FD map to make bugs apparent.  */
 656               p->fdmap[i] = -1;
 657               p->fdmap[j] = -1;
 658               return 0;
 659             }
 660     }
 661
 662   p->last_errno = EMFILE;
 663   return -1;
 664 }
 665
 666 /* Stub functions for pipe support.  They should always be overridden in
 667    targets using the pipe support, but that's up to the target.  */
 668
 669 /* Called when the simulator says that the pipe at (reader, writer) is
 670    now empty (so the writer should leave its waiting state).  */
 671
 672 static void
 673 os_pipe_empty (p, reader, writer)
 674      host_callback *p;
 675      int reader;
 676      int writer;
 677 {
 678 }
 679
 680 /* Called when the simulator says the pipe at (reader, writer) is now
 681    non-empty (so the writer should wait).  */
 682
 683 static void
 684 os_pipe_nonempty (p, reader, writer)
 685      host_callback *p;
 686      int reader;
 687      int writer;
 688 {
 689 }
 690
 691 static int
 692 os_shutdown (p)
 693      host_callback *p;
 694 {
 695   int i, next, j;
 696   for (i = 0; i < MAX_CALLBACK_FDS; i++)
 697     {
 698       int do_close = 1;
 699
 700       /* Zero out all pipe state.  Don't call callbacks for non-empty
 701          pipes; the target program has likely terminated at this point
 702          or we're called at initialization time.  */
 703       p->ispipe[i] = 0;
 704       p->pipe_buffer[i].size = 0;
 705       p->pipe_buffer[i].buffer = NULL;
 706
 707       next = p->fd_buddy[i];
 708       if (next < 0)
 709         continue;
 710       do
 711         {
 712           j = next;
 713           if (j == MAX_CALLBACK_FDS)
 714             do_close = 0;
 715           next = p->fd_buddy[j];
 716           p->fd_buddy[j] = -1;
 717           /* At the initial call of os_init, we got -1, 0, 0, 0, ...  */
 718           if (next < 0)
 719             {
 720               p->fd_buddy[i] = -1;
 721               do_close = 0;
 722               break;
 723             }
 724         }
 725       while (j != i);
 726       if (do_close)
 727         close (p->fdmap[i]);
 728     }
 729   return 1;
 730 }
 731
 732 static int
 733 os_init (p)
 734      host_callback *p;
 735 {
 736   int i;
 737
 738   os_shutdown (p);
 739   for (i = 0; i < 3; i++)
 740     {
 741       p->fdmap[i] = i;
 742       p->fd_buddy[i] = i - 1;
 743     }
 744   p->fd_buddy[0] = MAX_CALLBACK_FDS;
 745   p->fd_buddy[MAX_CALLBACK_FDS] = 2;
 746
 747   p->syscall_map = cb_init_syscall_map;
 748   p->errno_map = cb_init_errno_map;
 749   p->open_map = cb_init_open_map;
 750
 751   return 1;
 752 }
 753
 754 /* DEPRECATED */
 755
 756 /* VARARGS */
 757 static void
 758 os_printf_filtered (host_callback *p ATTRIBUTE_UNUSED, const char *format, ...)
 759 {
 760   va_list args;
 761   va_start (args, format);
 762
 763   vfprintf (stdout, format, args);
 764   va_end (args);
 765 }
 766
 767 /* VARARGS */
 768 static void
 769 os_vprintf_filtered (host_callback *p ATTRIBUTE_UNUSED, const char *format, va_list args)
 770 {
 771   vprintf (format, args);
 772 }
 773
 774 /* VARARGS */
 775 static void
 776 os_evprintf_filtered (host_callback *p ATTRIBUTE_UNUSED, const char *format, va_list args)
 777 {
 778   vfprintf (stderr, format, args);
 779 }
 780
 781 /* VARARGS */
 782 static void
 783 os_error (host_callback *p ATTRIBUTE_UNUSED, const char *format, ...)
 784 {
 785   va_list args;
 786   va_start (args, format);
 787
 788   vfprintf (stderr, format, args);
 789   fprintf (stderr, "\n");
 790
 791   va_end (args);
 792   exit (1);
 793 }
 794
 795 host_callback default_callback =
 796 {
 797   os_close,
 798   os_get_errno,
 799   os_isatty,
 800   os_lseek,
 801   os_open,
 802   os_read,
 803   os_read_stdin,
 804   os_rename,
 805   os_system,
 806   os_time,
 807   os_unlink,
 808   os_write,
 809   os_write_stdout,
 810   os_flush_stdout,
 811   os_write_stderr,
 812   os_flush_stderr,
 813
 814   os_stat,
 815   os_fstat,
 816   os_lstat,
 817
 818   os_ftruncate,
 819   os_truncate,
 820
 821   os_pipe,
 822   os_pipe_empty,
 823   os_pipe_nonempty,
 824
 825   os_poll_quit,
 826
 827   os_shutdown,
 828   os_init,
 829
 830   os_printf_filtered,  /* deprecated */
 831
 832   os_vprintf_filtered,
 833   os_evprintf_filtered,
 834   os_error,
 835
 836   0,            /* last errno */
 837
 838   { 0, },       /* fdmap */
 839   { -1, },      /* fd_buddy */
 840   { 0, },       /* ispipe */
 841   { { 0, 0 }, }, /* pipe_buffer */
 842
 843   0, /* syscall_map */
 844   0, /* errno_map */
 845   0, /* open_map */
 846   0, /* signal_map */
 847   0, /* stat_map */
 848
 849   /* Defaults expected to be overridden at initialization, where needed.  */
 850   BFD_ENDIAN_UNKNOWN, /* target_endian */
 851   4, /* target_sizeof_int */
 852
 853   HOST_CALLBACK_MAGIC,
 854 };
 855 \f
 856 /* Read in a file describing the target's system call values.
 857    E.g. maybe someone will want to use something other than newlib.
 858    This assumes that the basic system call recognition and value passing/
 859    returning is supported.  So maybe some coding/recompilation will be
 860    necessary, but not as much.
 861
 862    If an error occurs, the existing mapping is not changed.  */
 863
 864 CB_RC
 865 cb_read_target_syscall_maps (cb, file)
 866      host_callback *cb;
 867      const char *file;
 868 {
 869   CB_TARGET_DEFS_MAP *syscall_map, *errno_map, *open_map, *signal_map;
 870   const char *stat_map;
 871   FILE *f;
 872
 873   if ((f = fopen (file, "r")) == NULL)
 874     return CB_RC_ACCESS;
 875
 876   /* ... read in and parse file ... */
 877
 878   fclose (f);
 879   return CB_RC_NO_MEM; /* FIXME:wip */
 880
 881   /* Free storage allocated for any existing maps.  */
 882   if (cb->syscall_map)
 883     free (cb->syscall_map);
 884   if (cb->errno_map)
 885     free (cb->errno_map);
 886   if (cb->open_map)
 887     free (cb->open_map);
 888   if (cb->signal_map)
 889     free (cb->signal_map);
 890   if (cb->stat_map)
 891     free ((PTR) cb->stat_map);
 892
 893   cb->syscall_map = syscall_map;
 894   cb->errno_map = errno_map;
 895   cb->open_map = open_map;
 896   cb->signal_map = signal_map;
 897   cb->stat_map = stat_map;
 898
 899   return CB_RC_OK;
 900 }
 901
 902 /* Translate the target's version of a syscall number to the host's.
 903    This isn't actually the host's version, rather a canonical form.
 904    ??? Perhaps this should be renamed to ..._canon_syscall.  */
 905
 906 int
 907 cb_target_to_host_syscall (cb, target_val)
 908      host_callback *cb;
 909      int target_val;
 910 {
 911   CB_TARGET_DEFS_MAP *m;
 912
 913   for (m = &cb->syscall_map[0]; m->target_val != -1; ++m)
 914     if (m->target_val == target_val)
 915       return m->host_val;
 916
 917   return -1;
 918 }
 919
 920 /* FIXME: sort tables if large.
 921    Alternatively, an obvious improvement for errno conversion is
 922    to machine generate a function with a large switch().  */
 923
 924 /* Translate the host's version of errno to the target's.  */
 925
 926 int
 927 cb_host_to_target_errno (cb, host_val)
 928      host_callback *cb;
 929      int host_val;
 930 {
 931   CB_TARGET_DEFS_MAP *m;
 932
 933   for (m = &cb->errno_map[0]; m->host_val; ++m)
 934     if (m->host_val == host_val)
 935       return m->target_val;
 936
 937   /* ??? Which error to return in this case is up for grabs.
 938      Note that some missing values may have standard alternatives.
 939      For now return 0 and require caller to deal with it.  */
 940   return 0;
 941 }
 942
 943 /* Given a set of target bitmasks for the open system call,
 944    return the host equivalent.
 945    Mapping open flag values is best done by looping so there's no need
 946    to machine generate this function.  */
 947
 948 int
 949 cb_target_to_host_open (cb, target_val)
 950      host_callback *cb;
 951      int target_val;
 952 {
 953   int host_val = 0;
 954   CB_TARGET_DEFS_MAP *m;
 955
 956   for (m = &cb->open_map[0]; m->host_val != -1; ++m)
 957     {
 958       switch (m->target_val)
 959         {
 960           /* O_RDONLY can be (and usually is) 0 which needs to be treated
 961              specially.  */
 962         case TARGET_O_RDONLY :
 963         case TARGET_O_WRONLY :
 964         case TARGET_O_RDWR :
 965           if ((target_val & (TARGET_O_RDONLY | TARGET_O_WRONLY | TARGET_O_RDWR))
 966               == m->target_val)
 967             host_val |= m->host_val;
 968           /* Handle the host/target differentiating between binary and
 969              text mode.  Only one case is of importance */
 970 #if ! defined (TARGET_O_BINARY) && defined (O_BINARY)
 971           host_val |= O_BINARY;
 972 #endif
 973           break;
 974         default :
 975           if ((m->target_val & target_val) == m->target_val)
 976             host_val |= m->host_val;
 977           break;
 978         }
 979     }
 980
 981   return host_val;
 982 }
 983
 984 /* Utility for e.g. cb_host_to_target_stat to store values in the target's
 985    stat struct.  */
 986
 987 void
 988 cb_store_target_endian (cb, p, size, val)
 989      host_callback *cb;
 990      char *p;
 991      int size;
 992      long val; /* ??? must be as big as target word size */
 993 {
 994   if (cb->target_endian == BFD_ENDIAN_BIG)
 995     {
 996       p += size;
 997       while (size-- > 0)
 998         {
 999           *--p = val;
1000           val >>= 8;
1001         }
1002     }
1003   else
1004     {
1005       while (size-- > 0)
1006         {
1007           *p++ = val;
1008           val >>= 8;
1009         }
1010     }
1011 }
1012
1013 /* Translate a host's stat struct into a target's.
1014    If HS is NULL, just compute the length of the buffer required,
1015    TS is ignored.
1016
1017    The result is the size of the target's stat struct,
1018    or zero if an error occurred during the translation.  */
1019
1020 int
1021 cb_host_to_target_stat (cb, hs, ts)
1022      host_callback *cb;
1023      const struct stat *hs;
1024      PTR ts;
1025 {
1026   const char *m = cb->stat_map;
1027   char *p;
1028
1029   if (hs == NULL)
1030     ts = NULL;
1031   p = ts;
1032
1033   while (m)
1034     {
1035       char *q = strchr (m, ',');
1036       int size;
1037
1038       /* FIXME: Use sscanf? */
1039       if (q == NULL)
1040         {
1041           /* FIXME: print error message */
1042           return 0;
1043         }
1044       size = atoi (q + 1);
1045       if (size == 0)
1046         {
1047           /* FIXME: print error message */
1048           return 0;
1049         }
1050
1051       if (hs != NULL)
1052         {
1053           if (0)
1054             ;
1055           /* Defined here to avoid emacs indigestion on a lone "else".  */
1056 #undef ST_x
1057 #define ST_x(FLD)                                       \
1058           else if (strncmp (m, #FLD, q - m) == 0)       \
1059             cb_store_target_endian (cb, p, size, hs->FLD)
1060
1061 #ifdef HAVE_STRUCT_STAT_ST_DEV
1062           ST_x (st_dev);
1063 #endif
1064 #ifdef HAVE_STRUCT_STAT_ST_INO
1065           ST_x (st_ino);
1066 #endif
1067 #ifdef HAVE_STRUCT_STAT_ST_MODE
1068           ST_x (st_mode);
1069 #endif
1070 #ifdef HAVE_STRUCT_STAT_ST_NLINK
1071           ST_x (st_nlink);
1072 #endif
1073 #ifdef HAVE_STRUCT_STAT_ST_UID
1074           ST_x (st_uid);
1075 #endif
1076 #ifdef HAVE_STRUCT_STAT_ST_GID
1077           ST_x (st_gid);
1078 #endif
1079 #ifdef HAVE_STRUCT_STAT_ST_RDEV
1080           ST_x (st_rdev);
1081 #endif
1082 #ifdef HAVE_STRUCT_STAT_ST_SIZE
1083           ST_x (st_size);
1084 #endif
1085 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
1086           ST_x (st_blksize);
1087 #endif
1088 #ifdef HAVE_STRUCT_STAT_ST_BLOCKS
1089           ST_x (st_blocks);
1090 #endif
1091 #ifdef HAVE_STRUCT_STAT_ST_ATIME
1092           ST_x (st_atime);
1093 #endif
1094 #ifdef HAVE_STRUCT_STAT_ST_MTIME
1095           ST_x (st_mtime);
1096 #endif
1097 #ifdef HAVE_STRUCT_STAT_ST_CTIME
1098           ST_x (st_ctime);
1099 #endif
1100 #undef ST_x
1101           /* FIXME:wip */
1102           else
1103             /* Unsupported field, store 0.  */
1104             cb_store_target_endian (cb, p, size, 0);
1105         }
1106
1107       p += size;
1108       m = strchr (q, ':');
1109       if (m)
1110         ++m;
1111     }
1112
1113   return p - (char *) ts;
1114 }
1115 \f
1116 /* Cover functions to the vfprintf callbacks.
1117
1118    ??? If one thinks of the callbacks as a subsystem onto itself [or part of
1119    a larger "remote target subsystem"] with a well defined interface, then
1120    one would think that the subsystem would provide these.  However, until
1121    one is allowed to create such a subsystem (with its own source tree
1122    independent of any particular user), such a critter can't exist.  Thus
1123    these functions are here for the time being.  */
1124
1125 void
1126 sim_cb_printf (host_callback *p, const char *fmt, ...)
1127 {
1128   va_list ap;
1129
1130   va_start (ap, fmt);
1131   p->vprintf_filtered (p, fmt, ap);
1132   va_end (ap);
1133 }
1134
1135 void
1136 sim_cb_eprintf (host_callback *p, const char *fmt, ...)
1137 {
1138   va_list ap;
1139
1140   va_start (ap, fmt);
1141   p->evprintf_filtered (p, fmt, ap);
1142   va_end (ap);
1143 }
1144
1145 int
1146 cb_is_stdin (host_callback *cb, int fd)
1147 {
1148   return fdbad (cb, fd) ? 0 : fdmap (cb, fd) == 0;
1149 }
1150
1151 int
1152 cb_is_stdout (host_callback *cb, int fd)
1153 {
1154   return fdbad (cb, fd) ? 0 : fdmap (cb, fd) == 1;
1155 }
1156
1157 int
1158 cb_is_stderr (host_callback *cb, int fd)
1159 {
1160   return fdbad (cb, fd) ? 0 : fdmap (cb, fd) == 2;
1161 }