sim/common/callback.c

   1 /* Remote target callback routines.
   2    Copyright 1995-2014 Free Software Foundation, Inc.
   3    Contributed by Cygnus Solutions.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 /* This file provides a standard way for targets to talk to the host OS
  21    level.  */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include "cconfig.h"
  25 #endif
  26 #include "config.h"
  27 #include "ansidecl.h"
  28 #include <stdarg.h>
  29 #include <stdio.h>
  30 #ifdef HAVE_STDLIB_H
  31 #include <stdlib.h>
  32 #endif
  33 #ifdef HAVE_STRING_H
  34 #include <string.h>
  35 #else
  36 #ifdef HAVE_STRINGS_H
  37 #include <strings.h>
  38 #endif
  39 #endif
  40 #ifdef HAVE_LIMITS_H
  41 /* For PIPE_BUF.  */
  42 #include <limits.h>
  43 #endif
  44 #include <errno.h>
  45 #include <fcntl.h>
  46 #include <time.h>
  47 #include <sys/types.h>
  48 #include <sys/stat.h>
  49 #include "gdb/callback.h"
  50 #include "targ-vals.h"
  51 /* For xmalloc.  */
  52 #include "libiberty.h"
  53
  54 #ifdef HAVE_UNISTD_H
  55 #include <unistd.h>
  56 #endif
  57
  58 #ifndef PIPE_BUF
  59 #define PIPE_BUF 512
  60 #endif
  61
  62 /* ??? sim_cb_printf should be cb_printf, but until the callback support is
  63    broken out of the simulator directory, these are here to not require
  64    sim-utils.h.  */
  65 void sim_cb_printf PARAMS ((host_callback *, const char *, ...));
  66 void sim_cb_eprintf PARAMS ((host_callback *, const char *, ...));
  67
  68 extern CB_TARGET_DEFS_MAP cb_init_syscall_map[];
  69 extern CB_TARGET_DEFS_MAP cb_init_errno_map[];
  70 extern CB_TARGET_DEFS_MAP cb_init_open_map[];
  71
  72 extern int system PARAMS ((const char *));
  73
  74 static int os_init PARAMS ((host_callback *));
  75 static int os_shutdown PARAMS ((host_callback *));
  76 static int os_unlink PARAMS ((host_callback *, const char *));
  77 static long os_time PARAMS ((host_callback *, long *));
  78 static int os_system PARAMS ((host_callback *, const char *));
  79 static int os_rename PARAMS ((host_callback *, const char *, const char *));
  80 static int os_write_stdout PARAMS ((host_callback *, const char *, int));
  81 static void os_flush_stdout PARAMS ((host_callback *));
  82 static int os_write_stderr PARAMS ((host_callback *, const char *, int));
  83 static void os_flush_stderr PARAMS ((host_callback *));
  84 static int os_write PARAMS ((host_callback *, int, const char *, int));
  85 static int os_read_stdin PARAMS ((host_callback *, char *, int));
  86 static int os_read PARAMS ((host_callback *, int, char *, int));
  87 static int os_open PARAMS ((host_callback *, const char *, int));
  88 static int os_lseek PARAMS ((host_callback *, int, long, int));
  89 static int os_isatty PARAMS ((host_callback *, int));
  90 static int os_get_errno PARAMS ((host_callback *));
  91 static int os_close PARAMS ((host_callback *, int));
  92 static void os_vprintf_filtered PARAMS ((host_callback *, const char *, va_list));
  93 static void os_evprintf_filtered PARAMS ((host_callback *, const char *, va_list));
  94 static void os_error PARAMS ((host_callback *, const char *, ...))
  95 #ifdef __GNUC__
  96   __attribute__ ((__noreturn__))
  97 #endif
  98   ;
  99 static int fdmap PARAMS ((host_callback *, int));
 100 static int fdbad PARAMS ((host_callback *, int));
 101 static int wrap PARAMS ((host_callback *, int));
 102
 103 /* Set the callback copy of errno from what we see now.  */
 104
 105 static int
 106 wrap (p, val)
 107      host_callback *p;
 108      int val;
 109 {
 110   p->last_errno = errno;
 111   return val;
 112 }
 113
 114 /* Make sure the FD provided is ok.  If not, return non-zero
 115    and set errno. */
 116
 117 static int
 118 fdbad (p, fd)
 119      host_callback *p;
 120      int fd;
 121 {
 122   if (fd < 0 || fd > MAX_CALLBACK_FDS || p->fd_buddy[fd] < 0)
 123     {
 124       p->last_errno = EBADF;
 125       return -1;
 126     }
 127   return 0;
 128 }
 129
 130 static int
 131 fdmap (p, fd)
 132      host_callback *p;
 133      int fd;
 134 {
 135   return p->fdmap[fd];
 136 }
 137
 138 static int
 139 os_close (p, fd)
 140      host_callback *p;
 141      int fd;
 142 {
 143   int result;
 144   int i, next;
 145
 146   result = fdbad (p, fd);
 147   if (result)
 148     return result;
 149   /* If this file descripter has one or more buddies (originals /
 150      duplicates from a dup), just remove it from the circular list.  */
 151   for (i = fd; (next = p->fd_buddy[i]) != fd; )
 152     i = next;
 153   if (fd != i)
 154     p->fd_buddy[i] = p->fd_buddy[fd];
 155   else
 156     {
 157       if (p->ispipe[fd])
 158         {
 159           int other = p->ispipe[fd];
 160           int reader, writer;
 161
 162           if (other > 0)
 163             {
 164               /* Closing the read side.  */
 165               reader = fd;
 166               writer = other;
 167             }
 168           else
 169             {
 170               /* Closing the write side.  */
 171               writer = fd;
 172               reader = -other;
 173             }
 174
 175           /* If there was data in the buffer, make a last "now empty"
 176              call, then deallocate data.  */
 177           if (p->pipe_buffer[writer].buffer != NULL)
 178             {
 179               (*p->pipe_empty) (p, reader, writer);
 180               free (p->pipe_buffer[writer].buffer);
 181               p->pipe_buffer[writer].buffer = NULL;
 182             }
 183
 184           /* Clear pipe data for this side.  */
 185           p->pipe_buffer[fd].size = 0;
 186           p->ispipe[fd] = 0;
 187
 188           /* If this was the first close, mark the other side as the
 189              only remaining side.  */
 190           if (fd != abs (other))
 191             p->ispipe[abs (other)] = -other;
 192           p->fd_buddy[fd] = -1;
 193           return 0;
 194         }
 195
 196       result = wrap (p, close (fdmap (p, fd)));
 197     }
 198   p->fd_buddy[fd] = -1;
 199
 200   return result;
 201 }
 202
 203
 204 /* taken from gdb/util.c:notice_quit() - should be in a library */
 205
 206
 207 #if defined(__GO32__) || defined (_MSC_VER)
 208 static int
 209 os_poll_quit (p)
 210      host_callback *p;
 211 {
 212 #if defined(__GO32__)
 213   int kbhit ();
 214   int getkey ();
 215   if (kbhit ())
 216     {
 217       int k = getkey ();
 218       if (k == 1)
 219         {
 220           return 1;
 221         }
 222       else if (k == 2)
 223         {
 224           return 1;
 225         }
 226       else
 227         {
 228           sim_cb_eprintf (p, "CTRL-A to quit, CTRL-B to quit harder\n");
 229         }
 230     }
 231 #endif
 232 #if defined (_MSC_VER)
 233   /* NB - this will not compile! */
 234   int k = win32pollquit ();
 235   if (k == 1)
 236     return 1;
 237   else if (k == 2)
 238     return 1;
 239 #endif
 240   return 0;
 241 }
 242 #else
 243 #define os_poll_quit 0
 244 #endif /* defined(__GO32__) || defined(_MSC_VER) */
 245
 246 static int
 247 os_get_errno (p)
 248      host_callback *p;
 249 {
 250   return cb_host_to_target_errno (p, p->last_errno);
 251 }
 252
 253
 254 static int
 255 os_isatty (p, fd)
 256      host_callback *p;
 257      int fd;
 258 {
 259   int result;
 260
 261   result = fdbad (p, fd);
 262   if (result)
 263     return result;
 264   result = wrap (p, isatty (fdmap (p, fd)));
 265
 266   return result;
 267 }
 268
 269 static int
 270 os_lseek (p, fd, off, way)
 271      host_callback *p;
 272      int fd;
 273      long off;
 274      int way;
 275 {
 276   int result;
 277
 278   result = fdbad (p, fd);
 279   if (result)
 280     return result;
 281   result = wrap (p, lseek (fdmap (p, fd), off, way));
 282   return result;
 283 }
 284
 285 static int
 286 os_open (p, name, flags)
 287      host_callback *p;
 288      const char *name;
 289      int flags;
 290 {
 291   int i;
 292   for (i = 0; i < MAX_CALLBACK_FDS; i++)
 293     {
 294       if (p->fd_buddy[i] < 0)
 295         {
 296           int f = open (name, cb_target_to_host_open (p, flags), 0644);
 297           if (f < 0)
 298             {
 299               p->last_errno = errno;
 300               return f;
 301             }
 302           p->fd_buddy[i] = i;
 303           p->fdmap[i] = f;
 304           return i;
 305         }
 306     }
 307   p->last_errno = EMFILE;
 308   return -1;
 309 }
 310
 311 static int
 312 os_read (p, fd, buf, len)
 313      host_callback *p;
 314      int fd;
 315      char *buf;
 316      int len;
 317 {
 318   int result;
 319
 320   result = fdbad (p, fd);
 321   if (result)
 322     return result;
 323   if (p->ispipe[fd])
 324     {
 325       int writer = p->ispipe[fd];
 326
 327       /* Can't read from the write-end.  */
 328       if (writer < 0)
 329         {
 330           p->last_errno = EBADF;
 331           return -1;
 332         }
 333
 334       /* Nothing to read if nothing is written.  */
 335       if (p->pipe_buffer[writer].size == 0)
 336         return 0;
 337
 338       /* Truncate read request size to buffer size minus what's already
 339          read.  */
 340       if (len > p->pipe_buffer[writer].size - p->pipe_buffer[fd].size)
 341         len = p->pipe_buffer[writer].size - p->pipe_buffer[fd].size;
 342
 343       memcpy (buf, p->pipe_buffer[writer].buffer + p->pipe_buffer[fd].size,
 344               len);
 345
 346       /* Account for what we just read.  */
 347       p->pipe_buffer[fd].size += len;
 348
 349       /* If we've read everything, empty and deallocate the buffer and
 350          signal buffer-empty to client.  (This isn't expected to be a
 351          hot path in the simulator, so we don't hold on to the buffer.)  */
 352       if (p->pipe_buffer[fd].size == p->pipe_buffer[writer].size)
 353         {
 354           free (p->pipe_buffer[writer].buffer);
 355           p->pipe_buffer[writer].buffer = NULL;
 356           p->pipe_buffer[fd].size = 0;
 357           p->pipe_buffer[writer].size = 0;
 358           (*p->pipe_empty) (p, fd, writer);
 359         }
 360
 361       return len;
 362     }
 363
 364   result = wrap (p, read (fdmap (p, fd), buf, len));
 365   return result;
 366 }
 367
 368 static int
 369 os_read_stdin (p, buf, len)
 370      host_callback *p;
 371      char *buf;
 372      int len;
 373 {
 374   return wrap (p, read (0, buf, len));
 375 }
 376
 377 static int
 378 os_write (p, fd, buf, len)
 379      host_callback *p;
 380      int fd;
 381      const char *buf;
 382      int len;
 383 {
 384   int result;
 385   int real_fd;
 386
 387   result = fdbad (p, fd);
 388   if (result)
 389     return result;
 390
 391   if (p->ispipe[fd])
 392     {
 393       int reader = -p->ispipe[fd];
 394
 395       /* Can't write to the read-end.  */
 396       if (reader < 0)
 397         {
 398           p->last_errno = EBADF;
 399           return -1;
 400         }
 401
 402       /* Can't write to pipe with closed read end.
 403          FIXME: We should send a SIGPIPE.  */
 404       if (reader == fd)
 405         {
 406           p->last_errno = EPIPE;
 407           return -1;
 408         }
 409
 410       /* As a sanity-check, we bail out it the buffered contents is much
 411          larger than the size of the buffer on the host.  We don't want
 412          to run out of memory in the simulator due to a target program
 413          bug if we can help it.  Unfortunately, regarding the value that
 414          reaches the simulated program, it's no use returning *less*
 415          than the requested amount, because cb_syscall loops calling
 416          this function until the whole amount is done.  */
 417       if (p->pipe_buffer[fd].size + len > 10 * PIPE_BUF)
 418         {
 419           p->last_errno = EFBIG;
 420           return -1;
 421         }
 422
 423       p->pipe_buffer[fd].buffer
 424         = xrealloc (p->pipe_buffer[fd].buffer, p->pipe_buffer[fd].size + len);
 425       memcpy (p->pipe_buffer[fd].buffer + p->pipe_buffer[fd].size,
 426               buf, len);
 427       p->pipe_buffer[fd].size += len;
 428
 429       (*p->pipe_nonempty) (p, reader, fd);
 430       return len;
 431     }
 432
 433   real_fd = fdmap (p, fd);
 434   switch (real_fd)
 435     {
 436     default:
 437       result = wrap (p, write (real_fd, buf, len));
 438       break;
 439     case 1:
 440       result = p->write_stdout (p, buf, len);
 441       break;
 442     case 2:
 443       result = p->write_stderr (p, buf, len);
 444       break;
 445     }
 446   return result;
 447 }
 448
 449 static int
 450 os_write_stdout (p, buf, len)
 451      host_callback *p ATTRIBUTE_UNUSED;
 452      const char *buf;
 453      int len;
 454 {
 455   return fwrite (buf, 1, len, stdout);
 456 }
 457
 458 static void
 459 os_flush_stdout (p)
 460      host_callback *p ATTRIBUTE_UNUSED;
 461 {
 462   fflush (stdout);
 463 }
 464
 465 static int
 466 os_write_stderr (p, buf, len)
 467      host_callback *p ATTRIBUTE_UNUSED;
 468      const char *buf;
 469      int len;
 470 {
 471   return fwrite (buf, 1, len, stderr);
 472 }
 473
 474 static void
 475 os_flush_stderr (p)
 476      host_callback *p ATTRIBUTE_UNUSED;
 477 {
 478   fflush (stderr);
 479 }
 480
 481 static int
 482 os_rename (p, f1, f2)
 483      host_callback *p;
 484      const char *f1;
 485      const char *f2;
 486 {
 487   return wrap (p, rename (f1, f2));
 488 }
 489
 490
 491 static int
 492 os_system (p, s)
 493      host_callback *p;
 494      const char *s;
 495 {
 496   return wrap (p, system (s));
 497 }
 498
 499 static long
 500 os_time (p, t)
 501      host_callback *p;
 502      long *t;
 503 {
 504   return wrap (p, time (t));
 505 }
 506
 507
 508 static int
 509 os_unlink (p, f1)
 510      host_callback *p;
 511      const char *f1;
 512 {
 513   return wrap (p, unlink (f1));
 514 }
 515
 516 static int
 517 os_stat (p, file, buf)
 518      host_callback *p;
 519      const char *file;
 520      struct stat *buf;
 521 {
 522   /* ??? There is an issue of when to translate to the target layout.
 523      One could do that inside this function, or one could have the
 524      caller do it.  It's more flexible to let the caller do it, though
 525      I'm not sure the flexibility will ever be useful.  */
 526   return wrap (p, stat (file, buf));
 527 }
 528
 529 static int
 530 os_fstat (p, fd, buf)
 531      host_callback *p;
 532      int fd;
 533      struct stat *buf;
 534 {
 535   if (fdbad (p, fd))
 536     return -1;
 537
 538   if (p->ispipe[fd])
 539     {
 540 #if defined (HAVE_STRUCT_STAT_ST_ATIME) || defined (HAVE_STRUCT_STAT_ST_CTIME) || defined (HAVE_STRUCT_STAT_ST_MTIME)
 541       time_t t = (*p->time) (p, NULL);
 542 #endif
 543
 544       /* We have to fake the struct stat contents, since the pipe is
 545          made up in the simulator.  */
 546       memset (buf, 0, sizeof (*buf));
 547
 548 #ifdef HAVE_STRUCT_STAT_ST_MODE
 549       buf->st_mode = S_IFIFO;
 550 #endif
 551
 552       /* If more accurate tracking than current-time is needed (for
 553          example, on GNU/Linux we get accurate numbers), the p->time
 554          callback (which may be something other than os_time) should
 555          happen for each read and write, and we'd need to keep track of
 556          atime, ctime and mtime.  */
 557 #ifdef HAVE_STRUCT_STAT_ST_ATIME
 558       buf->st_atime = t;
 559 #endif
 560 #ifdef HAVE_STRUCT_STAT_ST_CTIME
 561       buf->st_ctime = t;
 562 #endif
 563 #ifdef HAVE_STRUCT_STAT_ST_MTIME
 564       buf->st_mtime = t;
 565 #endif
 566       return 0;
 567     }
 568
 569   /* ??? There is an issue of when to translate to the target layout.
 570      One could do that inside this function, or one could have the
 571      caller do it.  It's more flexible to let the caller do it, though
 572      I'm not sure the flexibility will ever be useful.  */
 573   return wrap (p, fstat (fdmap (p, fd), buf));
 574 }
 575
 576 static int
 577 os_lstat (p, file, buf)
 578      host_callback *p;
 579      const char *file;
 580      struct stat *buf;
 581 {
 582   /* NOTE: hpn/2004-12-12: Same issue here as with os_fstat.  */
 583 #ifdef HAVE_LSTAT
 584   return wrap (p, lstat (file, buf));
 585 #else
 586   return wrap (p, stat (file, buf));
 587 #endif
 588 }
 589
 590 static int
 591 os_ftruncate (p, fd, len)
 592      host_callback *p;
 593      int fd;
 594      long len;
 595 {
 596   int result;
 597
 598   result = fdbad (p, fd);
 599   if (p->ispipe[fd])
 600     {
 601       p->last_errno = EINVAL;
 602       return -1;
 603     }
 604   if (result)
 605     return result;
 606 #ifdef HAVE_FTRUNCATE
 607   result = wrap (p, ftruncate (fdmap (p, fd), len));
 608 #else
 609   p->last_errno = EINVAL;
 610   result = -1;
 611 #endif
 612   return result;
 613 }
 614
 615 static int
 616 os_truncate (p, file, len)
 617      host_callback *p;
 618      const char *file;
 619      long len;
 620 {
 621 #ifdef HAVE_TRUNCATE
 622   return wrap (p, truncate (file, len));
 623 #else
 624   p->last_errno = EINVAL;
 625   return -1;
 626 #endif
 627 }
 628
 629 static int
 630 os_pipe (p, filedes)
 631      host_callback *p;
 632      int *filedes;
 633 {
 634   int i;
 635
 636   /* We deliberately don't use fd 0.  It's probably stdin anyway.  */
 637   for (i = 1; i < MAX_CALLBACK_FDS; i++)
 638     {
 639       int j;
 640
 641       if (p->fd_buddy[i] < 0)
 642         for (j = i + 1; j < MAX_CALLBACK_FDS; j++)
 643           if (p->fd_buddy[j] < 0)
 644             {
 645               /* Found two free fd:s.  Set stat to allocated and mark
 646                  pipeness.  */
 647               p->fd_buddy[i] = i;
 648               p->fd_buddy[j] = j;
 649               p->ispipe[i] = j;
 650               p->ispipe[j] = -i;
 651               filedes[0] = i;
 652               filedes[1] = j;
 653
 654               /* Poison the FD map to make bugs apparent.  */
 655               p->fdmap[i] = -1;
 656               p->fdmap[j] = -1;
 657               return 0;
 658             }
 659     }
 660
 661   p->last_errno = EMFILE;
 662   return -1;
 663 }
 664
 665 /* Stub functions for pipe support.  They should always be overridden in
 666    targets using the pipe support, but that's up to the target.  */
 667
 668 /* Called when the simulator says that the pipe at (reader, writer) is
 669    now empty (so the writer should leave its waiting state).  */
 670
 671 static void
 672 os_pipe_empty (p, reader, writer)
 673      host_callback *p;
 674      int reader;
 675      int writer;
 676 {
 677 }
 678
 679 /* Called when the simulator says the pipe at (reader, writer) is now
 680    non-empty (so the writer should wait).  */
 681
 682 static void
 683 os_pipe_nonempty (p, reader, writer)
 684      host_callback *p;
 685      int reader;
 686      int writer;
 687 {
 688 }
 689
 690 static int
 691 os_shutdown (p)
 692      host_callback *p;
 693 {
 694   int i, next, j;
 695   for (i = 0; i < MAX_CALLBACK_FDS; i++)
 696     {
 697       int do_close = 1;
 698
 699       /* Zero out all pipe state.  Don't call callbacks for non-empty
 700          pipes; the target program has likely terminated at this point
 701          or we're called at initialization time.  */
 702       p->ispipe[i] = 0;
 703       p->pipe_buffer[i].size = 0;
 704       p->pipe_buffer[i].buffer = NULL;
 705
 706       next = p->fd_buddy[i];
 707       if (next < 0)
 708         continue;
 709       do
 710         {
 711           j = next;
 712           if (j == MAX_CALLBACK_FDS)
 713             do_close = 0;
 714           next = p->fd_buddy[j];
 715           p->fd_buddy[j] = -1;
 716           /* At the initial call of os_init, we got -1, 0, 0, 0, ...  */
 717           if (next < 0)
 718             {
 719               p->fd_buddy[i] = -1;
 720               do_close = 0;
 721               break;
 722             }
 723         }
 724       while (j != i);
 725       if (do_close)
 726         close (p->fdmap[i]);
 727     }
 728   return 1;
 729 }
 730
 731 static int
 732 os_init (p)
 733      host_callback *p;
 734 {
 735   int i;
 736
 737   os_shutdown (p);
 738   for (i = 0; i < 3; i++)
 739     {
 740       p->fdmap[i] = i;
 741       p->fd_buddy[i] = i - 1;
 742     }
 743   p->fd_buddy[0] = MAX_CALLBACK_FDS;
 744   p->fd_buddy[MAX_CALLBACK_FDS] = 2;
 745
 746   p->syscall_map = cb_init_syscall_map;
 747   p->errno_map = cb_init_errno_map;
 748   p->open_map = cb_init_open_map;
 749
 750   return 1;
 751 }
 752
 753 /* DEPRECATED */
 754
 755 /* VARARGS */
 756 static void
 757 os_printf_filtered (host_callback *p ATTRIBUTE_UNUSED, const char *format, ...)
 758 {
 759   va_list args;
 760   va_start (args, format);
 761
 762   vfprintf (stdout, format, args);
 763   va_end (args);
 764 }
 765
 766 /* VARARGS */
 767 static void
 768 os_vprintf_filtered (host_callback *p ATTRIBUTE_UNUSED, const char *format, va_list args)
 769 {
 770   vprintf (format, args);
 771 }
 772
 773 /* VARARGS */
 774 static void
 775 os_evprintf_filtered (host_callback *p ATTRIBUTE_UNUSED, const char *format, va_list args)
 776 {
 777   vfprintf (stderr, format, args);
 778 }
 779
 780 /* VARARGS */
 781 static void
 782 os_error (host_callback *p ATTRIBUTE_UNUSED, const char *format, ...)
 783 {
 784   va_list args;
 785   va_start (args, format);
 786
 787   vfprintf (stderr, format, args);
 788   fprintf (stderr, "\n");
 789
 790   va_end (args);
 791   exit (1);
 792 }
 793
 794 host_callback default_callback =
 795 {
 796   os_close,
 797   os_get_errno,
 798   os_isatty,
 799   os_lseek,
 800   os_open,
 801   os_read,
 802   os_read_stdin,
 803   os_rename,
 804   os_system,
 805   os_time,
 806   os_unlink,
 807   os_write,
 808   os_write_stdout,
 809   os_flush_stdout,
 810   os_write_stderr,
 811   os_flush_stderr,
 812
 813   os_stat,
 814   os_fstat,
 815   os_lstat,
 816
 817   os_ftruncate,
 818   os_truncate,
 819
 820   os_pipe,
 821   os_pipe_empty,
 822   os_pipe_nonempty,
 823
 824   os_poll_quit,
 825
 826   os_shutdown,
 827   os_init,
 828
 829   os_printf_filtered,  /* deprecated */
 830
 831   os_vprintf_filtered,
 832   os_evprintf_filtered,
 833   os_error,
 834
 835   0,            /* last errno */
 836
 837   { 0, },       /* fdmap */
 838   { -1, },      /* fd_buddy */
 839   { 0, },       /* ispipe */
 840   { { 0, 0 }, }, /* pipe_buffer */
 841
 842   0, /* syscall_map */
 843   0, /* errno_map */
 844   0, /* open_map */
 845   0, /* signal_map */
 846   0, /* stat_map */
 847
 848   /* Defaults expected to be overridden at initialization, where needed.  */
 849   BFD_ENDIAN_UNKNOWN, /* target_endian */
 850   4, /* target_sizeof_int */
 851
 852   HOST_CALLBACK_MAGIC,
 853 };
 854 \f
 855 /* Read in a file describing the target's system call values.
 856    E.g. maybe someone will want to use something other than newlib.
 857    This assumes that the basic system call recognition and value passing/
 858    returning is supported.  So maybe some coding/recompilation will be
 859    necessary, but not as much.
 860
 861    If an error occurs, the existing mapping is not changed.  */
 862
 863 CB_RC
 864 cb_read_target_syscall_maps (cb, file)
 865      host_callback *cb;
 866      const char *file;
 867 {
 868   CB_TARGET_DEFS_MAP *syscall_map, *errno_map, *open_map, *signal_map;
 869   const char *stat_map;
 870   FILE *f;
 871
 872   if ((f = fopen (file, "r")) == NULL)
 873     return CB_RC_ACCESS;
 874
 875   /* ... read in and parse file ... */
 876
 877   fclose (f);
 878   return CB_RC_NO_MEM; /* FIXME:wip */
 879
 880   /* Free storage allocated for any existing maps.  */
 881   if (cb->syscall_map)
 882     free (cb->syscall_map);
 883   if (cb->errno_map)
 884     free (cb->errno_map);
 885   if (cb->open_map)
 886     free (cb->open_map);
 887   if (cb->signal_map)
 888     free (cb->signal_map);
 889   if (cb->stat_map)
 890     free ((PTR) cb->stat_map);
 891
 892   cb->syscall_map = syscall_map;
 893   cb->errno_map = errno_map;
 894   cb->open_map = open_map;
 895   cb->signal_map = signal_map;
 896   cb->stat_map = stat_map;
 897
 898   return CB_RC_OK;
 899 }
 900
 901 /* Translate the target's version of a syscall number to the host's.
 902    This isn't actually the host's version, rather a canonical form.
 903    ??? Perhaps this should be renamed to ..._canon_syscall.  */
 904
 905 int
 906 cb_target_to_host_syscall (cb, target_val)
 907      host_callback *cb;
 908      int target_val;
 909 {
 910   CB_TARGET_DEFS_MAP *m;
 911
 912   for (m = &cb->syscall_map[0]; m->target_val != -1; ++m)
 913     if (m->target_val == target_val)
 914       return m->host_val;
 915
 916   return -1;
 917 }
 918
 919 /* FIXME: sort tables if large.
 920    Alternatively, an obvious improvement for errno conversion is
 921    to machine generate a function with a large switch().  */
 922
 923 /* Translate the host's version of errno to the target's.  */
 924
 925 int
 926 cb_host_to_target_errno (cb, host_val)
 927      host_callback *cb;
 928      int host_val;
 929 {
 930   CB_TARGET_DEFS_MAP *m;
 931
 932   for (m = &cb->errno_map[0]; m->host_val; ++m)
 933     if (m->host_val == host_val)
 934       return m->target_val;
 935
 936   /* ??? Which error to return in this case is up for grabs.
 937      Note that some missing values may have standard alternatives.
 938      For now return 0 and require caller to deal with it.  */
 939   return 0;
 940 }
 941
 942 /* Given a set of target bitmasks for the open system call,
 943    return the host equivalent.
 944    Mapping open flag values is best done by looping so there's no need
 945    to machine generate this function.  */
 946
 947 int
 948 cb_target_to_host_open (cb, target_val)
 949      host_callback *cb;
 950      int target_val;
 951 {
 952   int host_val = 0;
 953   CB_TARGET_DEFS_MAP *m;
 954
 955   for (m = &cb->open_map[0]; m->host_val != -1; ++m)
 956     {
 957       switch (m->target_val)
 958         {
 959           /* O_RDONLY can be (and usually is) 0 which needs to be treated
 960              specially.  */
 961         case TARGET_O_RDONLY :
 962         case TARGET_O_WRONLY :
 963         case TARGET_O_RDWR :
 964           if ((target_val & (TARGET_O_RDONLY | TARGET_O_WRONLY | TARGET_O_RDWR))
 965               == m->target_val)
 966             host_val |= m->host_val;
 967           /* Handle the host/target differentiating between binary and
 968              text mode.  Only one case is of importance */
 969 #if ! defined (TARGET_O_BINARY) && defined (O_BINARY)
 970           host_val |= O_BINARY;
 971 #endif
 972           break;
 973         default :
 974           if ((m->target_val & target_val) == m->target_val)
 975             host_val |= m->host_val;
 976           break;
 977         }
 978     }
 979
 980   return host_val;
 981 }
 982
 983 /* Utility for e.g. cb_host_to_target_stat to store values in the target's
 984    stat struct.  */
 985
 986 void
 987 cb_store_target_endian (cb, p, size, val)
 988      host_callback *cb;
 989      char *p;
 990      int size;
 991      long val; /* ??? must be as big as target word size */
 992 {
 993   if (cb->target_endian == BFD_ENDIAN_BIG)
 994     {
 995       p += size;
 996       while (size-- > 0)
 997         {
 998           *--p = val;
 999           val >>= 8;
1000         }
1001     }
1002   else
1003     {
1004       while (size-- > 0)
1005         {
1006           *p++ = val;
1007           val >>= 8;
1008         }
1009     }
1010 }
1011
1012 /* Translate a host's stat struct into a target's.
1013    If HS is NULL, just compute the length of the buffer required,
1014    TS is ignored.
1015
1016    The result is the size of the target's stat struct,
1017    or zero if an error occurred during the translation.  */
1018
1019 int
1020 cb_host_to_target_stat (cb, hs, ts)
1021      host_callback *cb;
1022      const struct stat *hs;
1023      PTR ts;
1024 {
1025   const char *m = cb->stat_map;
1026   char *p;
1027
1028   if (hs == NULL)
1029     ts = NULL;
1030   p = ts;
1031
1032   while (m)
1033     {
1034       char *q = strchr (m, ',');
1035       int size;
1036
1037       /* FIXME: Use sscanf? */
1038       if (q == NULL)
1039         {
1040           /* FIXME: print error message */
1041           return 0;
1042         }
1043       size = atoi (q + 1);
1044       if (size == 0)
1045         {
1046           /* FIXME: print error message */
1047           return 0;
1048         }
1049
1050       if (hs != NULL)
1051         {
1052           if (0)
1053             ;
1054           /* Defined here to avoid emacs indigestion on a lone "else".  */
1055 #undef ST_x
1056 #define ST_x(FLD)                                       \
1057           else if (strncmp (m, #FLD, q - m) == 0)       \
1058             cb_store_target_endian (cb, p, size, hs->FLD)
1059
1060 #ifdef HAVE_STRUCT_STAT_ST_DEV
1061           ST_x (st_dev);
1062 #endif
1063 #ifdef HAVE_STRUCT_STAT_ST_INO
1064           ST_x (st_ino);
1065 #endif
1066 #ifdef HAVE_STRUCT_STAT_ST_MODE
1067           ST_x (st_mode);
1068 #endif
1069 #ifdef HAVE_STRUCT_STAT_ST_NLINK
1070           ST_x (st_nlink);
1071 #endif
1072 #ifdef HAVE_STRUCT_STAT_ST_UID
1073           ST_x (st_uid);
1074 #endif
1075 #ifdef HAVE_STRUCT_STAT_ST_GID
1076           ST_x (st_gid);
1077 #endif
1078 #ifdef HAVE_STRUCT_STAT_ST_RDEV
1079           ST_x (st_rdev);
1080 #endif
1081 #ifdef HAVE_STRUCT_STAT_ST_SIZE
1082           ST_x (st_size);
1083 #endif
1084 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
1085           ST_x (st_blksize);
1086 #endif
1087 #ifdef HAVE_STRUCT_STAT_ST_BLOCKS
1088           ST_x (st_blocks);
1089 #endif
1090 #ifdef HAVE_STRUCT_STAT_ST_ATIME
1091           ST_x (st_atime);
1092 #endif
1093 #ifdef HAVE_STRUCT_STAT_ST_MTIME
1094           ST_x (st_mtime);
1095 #endif
1096 #ifdef HAVE_STRUCT_STAT_ST_CTIME
1097           ST_x (st_ctime);
1098 #endif
1099 #undef ST_x
1100           /* FIXME:wip */
1101           else
1102             /* Unsupported field, store 0.  */
1103             cb_store_target_endian (cb, p, size, 0);
1104         }
1105
1106       p += size;
1107       m = strchr (q, ':');
1108       if (m)
1109         ++m;
1110     }
1111
1112   return p - (char *) ts;
1113 }
1114 \f
1115 /* Cover functions to the vfprintf callbacks.
1116
1117    ??? If one thinks of the callbacks as a subsystem onto itself [or part of
1118    a larger "remote target subsystem"] with a well defined interface, then
1119    one would think that the subsystem would provide these.  However, until
1120    one is allowed to create such a subsystem (with its own source tree
1121    independent of any particular user), such a critter can't exist.  Thus
1122    these functions are here for the time being.  */
1123
1124 void
1125 sim_cb_printf (host_callback *p, const char *fmt, ...)
1126 {
1127   va_list ap;
1128
1129   va_start (ap, fmt);
1130   p->vprintf_filtered (p, fmt, ap);
1131   va_end (ap);
1132 }
1133
1134 void
1135 sim_cb_eprintf (host_callback *p, const char *fmt, ...)
1136 {
1137   va_list ap;
1138
1139   va_start (ap, fmt);
1140   p->evprintf_filtered (p, fmt, ap);
1141   va_end (ap);
1142 }
1143
1144 int
1145 cb_is_stdin (host_callback *cb, int fd)
1146 {
1147   return fdbad (cb, fd) ? 0 : fdmap (cb, fd) == 0;
1148 }
1149
1150 int
1151 cb_is_stdout (host_callback *cb, int fd)
1152 {
1153   return fdbad (cb, fd) ? 0 : fdmap (cb, fd) == 1;
1154 }
1155
1156 int
1157 cb_is_stderr (host_callback *cb, int fd)
1158 {
1159   return fdbad (cb, fd) ? 0 : fdmap (cb, fd) == 2;
1160 }