src/gamelog.cpp

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   4  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file gamelog.cpp Definition of functions used for logging of important changes in the game */
   9
  10 #include "stdafx.h"
  11 #include "saveload/saveload.h"
  12 #include "string_func.h"
  13 #include "settings_type.h"
  14 #include "gamelog_internal.h"
  15 #include "console_func.h"
  16 #include "debug.h"
  17 #include "date_func.h"
  18 #include "rev.h"
  19
  20 #include <stdarg.h>
  21
  22 #include "safeguards.h"
  23
  24 extern const SaveLoadVersion SAVEGAME_VERSION;  ///< current savegame version
  25
  26 extern SavegameType _savegame_type; ///< type of savegame we are loading
  27
  28 extern uint32 _ttdp_version;        ///< version of TTDP savegame (if applicable)
  29 extern SaveLoadVersion _sl_version; ///< the major savegame version identifier
  30 extern byte   _sl_minor_version;    ///< the minor savegame version, DO NOT USE!
  31
  32
  33 static GamelogActionType _gamelog_action_type = GLAT_NONE; ///< action to record if anything changes
  34
  35 LoggedAction *_gamelog_action = nullptr;        ///< first logged action
  36 uint _gamelog_actions         = 0;           ///< number of actions
  37 static LoggedAction *_current_action = nullptr; ///< current action we are logging, nullptr when there is no action active
  38
  39
  40 /**
  41  * Return the revision string for the current client version, for use in gamelog.
  42  * The string returned is at most GAMELOG_REVISION_LENGTH bytes long.
  43  */
  44 static const char * GetGamelogRevisionString()
  45 {
  46         /* Allocate a buffer larger than necessary (git revision hash is 40 bytes) to avoid truncation later */
  47         static char gamelog_revision[48] = { 0 };
  48         static_assert(lengthof(gamelog_revision) > GAMELOG_REVISION_LENGTH);
  49
  50         if (IsReleasedVersion()) {
  51                 return _openttd_revision;
  52         } else if (gamelog_revision[0] == 0) {
  53                 /* Prefix character indication revision status */
  54                 assert(_openttd_revision_modified < 3);
  55                 gamelog_revision[0] = "gum"[_openttd_revision_modified]; // g = "git", u = "unknown", m = "modified"
  56                 /* Append the revision hash */
  57                 strecat(gamelog_revision, _openttd_revision_hash, lastof(gamelog_revision));
  58                 /* Truncate string to GAMELOG_REVISION_LENGTH bytes */
  59                 gamelog_revision[GAMELOG_REVISION_LENGTH - 1] = '\0';
  60         }
  61         return gamelog_revision;
  62 }
  63
  64 /**
  65  * Stores information about new action, but doesn't allocate it
  66  * Action is allocated only when there is at least one change
  67  * @param at type of action
  68  */
  69 void GamelogStartAction(GamelogActionType at)
  70 {
  71         assert(_gamelog_action_type == GLAT_NONE); // do not allow starting new action without stopping the previous first
  72         _gamelog_action_type = at;
  73 }
  74
  75 /**
  76  * Stops logging of any changes
  77  */
  78 void GamelogStopAction()
  79 {
  80         assert(_gamelog_action_type != GLAT_NONE); // nobody should try to stop if there is no action in progress
  81
  82         bool print = _current_action != nullptr;
  83
  84         _current_action = nullptr;
  85         _gamelog_action_type = GLAT_NONE;
  86
  87         if (print) GamelogPrintDebug(5);
  88 }
  89
  90 void GamelogStopAnyAction()
  91 {
  92         if (_gamelog_action_type != GLAT_NONE) GamelogStopAction();
  93 }
  94
  95 /**
  96  * Frees the memory allocated by a gamelog
  97  */
  98 void GamelogFree(LoggedAction *gamelog_action, uint gamelog_actions)
  99 {
 100         for (uint i = 0; i < gamelog_actions; i++) {
 101                 const LoggedAction *la = &gamelog_action[i];
 102                 for (uint j = 0; j < la->changes; j++) {
 103                         const LoggedChange *lc = &la->change[j];
 104                         if (lc->ct == GLCT_SETTING) free(lc->setting.name);
 105                 }
 106                 free(la->change);
 107         }
 108
 109         free(gamelog_action);
 110 }
 111
 112 /**
 113  * Resets and frees all memory allocated - used before loading or starting a new game
 114  */
 115 void GamelogReset()
 116 {
 117         assert(_gamelog_action_type == GLAT_NONE);
 118         GamelogFree(_gamelog_action, _gamelog_actions);
 119
 120         _gamelog_action  = nullptr;
 121         _gamelog_actions = 0;
 122         _current_action  = nullptr;
 123 }
 124
 125 /**
 126  * Prints GRF ID, checksum and filename if found
 127  * @param buf The location in the buffer to draw
 128  * @param last The end of the buffer
 129  * @param grfid GRF ID
 130  * @param md5sum array of md5sum to print, if known
 131  * @param gc GrfConfig, if known
 132  * @return The buffer location.
 133  */
 134 static char *PrintGrfInfo(char *buf, const char *last, uint grfid, const uint8 *md5sum, const GRFConfig *gc)
 135 {
 136         char txt[40];
 137
 138         if (md5sum != nullptr) {
 139                 md5sumToString(txt, lastof(txt), md5sum);
 140                 buf += seprintf(buf, last, "GRF ID %08X, checksum %s", BSWAP32(grfid), txt);
 141         } else {
 142                 buf += seprintf(buf, last, "GRF ID %08X", BSWAP32(grfid));
 143         }
 144
 145         if (gc != nullptr) {
 146                 buf += seprintf(buf, last, ", filename: %s (md5sum matches)", gc->filename);
 147         } else {
 148                 gc = FindGRFConfig(grfid, FGCM_ANY);
 149                 if (gc != nullptr) {
 150                         buf += seprintf(buf, last, ", filename: %s (matches GRFID only)", gc->filename);
 151                 } else {
 152                         buf += seprintf(buf, last, ", unknown GRF");
 153                 }
 154         }
 155         return buf;
 156 }
 157
 158
 159 /** Text messages for various logged actions */
 160 static const char * const la_text[] = {
 161         "new game started",
 162         "game loaded",
 163         "GRF config changed",
 164         "cheat was used",
 165         "settings changed",
 166         "GRF bug triggered",
 167         "emergency savegame",
 168 };
 169
 170 static_assert(lengthof(la_text) == GLAT_END);
 171
 172 /**
 173  * Information about the presence of a Grf at a certain point during gamelog history
 174  * Note about missing Grfs:
 175  * Changes to missing Grfs are not logged including manual removal of the Grf.
 176  * So if the gamelog tells a Grf is missing we do not know whether it was readded or completely removed
 177  * at some later point.
 178  */
 179 struct GRFPresence{
 180         const GRFConfig *gc;  ///< GRFConfig, if known
 181         bool was_missing;     ///< Grf was missing during some gameload in the past
 182
 183         GRFPresence(const GRFConfig *gc) : gc(gc), was_missing(false) {}
 184         GRFPresence() = default;
 185 };
 186 typedef SmallMap<uint32, GRFPresence> GrfIDMapping;
 187
 188 /**
 189  * Prints active gamelog
 190  * @param proc the procedure to draw with
 191  */
 192 void GamelogPrint(GamelogPrintProc *proc)
 193 {
 194         char buffer[1024];
 195         GrfIDMapping grf_names;
 196
 197         proc("---- gamelog start ----");
 198
 199         const LoggedAction *laend = &_gamelog_action[_gamelog_actions];
 200
 201         for (const LoggedAction *la = _gamelog_action; la != laend; la++) {
 202                 assert((uint)la->at < GLAT_END);
 203
 204                 seprintf(buffer, lastof(buffer), "Tick %u: %s", (uint)la->tick, la_text[(uint)la->at]);
 205                 proc(buffer);
 206
 207                 const LoggedChange *lcend = &la->change[la->changes];
 208
 209                 for (const LoggedChange *lc = la->change; lc != lcend; lc++) {
 210                         char *buf = buffer;
 211
 212                         switch (lc->ct) {
 213                                 default: NOT_REACHED();
 214                                 case GLCT_MODE:
 215                                         buf += seprintf(buf, lastof(buffer), "New game mode: %u landscape: %u",
 216                                                 (uint)lc->mode.mode, (uint)lc->mode.landscape);
 217                                         break;
 218
 219                                 case GLCT_REVISION:
 220                                         buf += seprintf(buf, lastof(buffer), "Revision text changed to %s, savegame version %u, ",
 221                                                 lc->revision.text, lc->revision.slver);
 222
 223                                         switch (lc->revision.modified) {
 224                                                 case 0: buf += seprintf(buf, lastof(buffer), "not "); break;
 225                                                 case 1: buf += seprintf(buf, lastof(buffer), "maybe "); break;
 226                                                 default: break;
 227                                         }
 228
 229                                         buf += seprintf(buf, lastof(buffer), "modified, _openttd_newgrf_version = 0x%08x", lc->revision.newgrf);
 230                                         break;
 231
 232                                 case GLCT_OLDVER:
 233                                         buf += seprintf(buf, lastof(buffer), "Conversion from ");
 234                                         switch (lc->oldver.type) {
 235                                                 default: NOT_REACHED();
 236                                                 case SGT_OTTD:
 237                                                         buf += seprintf(buf, lastof(buffer), "OTTD savegame without gamelog: version %u, %u",
 238                                                                 GB(lc->oldver.version, 8, 16), GB(lc->oldver.version, 0, 8));
 239                                                         break;
 240
 241                                                 case SGT_TTO:
 242                                                         buf += seprintf(buf, lastof(buffer), "TTO savegame");
 243                                                         break;
 244
 245                                                 case SGT_TTD:
 246                                                         buf += seprintf(buf, lastof(buffer), "TTD savegame");
 247                                                         break;
 248
 249                                                 case SGT_TTDP1:
 250                                                 case SGT_TTDP2:
 251                                                         buf += seprintf(buf, lastof(buffer), "TTDP savegame, %s format",
 252                                                                 lc->oldver.type == SGT_TTDP1 ? "old" : "new");
 253                                                         if (lc->oldver.version != 0) {
 254                                                                 buf += seprintf(buf, lastof(buffer), ", TTDP version %u.%u.%u.%u",
 255                                                                         GB(lc->oldver.version, 24, 8), GB(lc->oldver.version, 20, 4),
 256                                                                         GB(lc->oldver.version, 16, 4), GB(lc->oldver.version, 0, 16));
 257                                                         }
 258                                                         break;
 259                                         }
 260                                         break;
 261
 262                                 case GLCT_SETTING:
 263                                         buf += seprintf(buf, lastof(buffer), "Setting changed: %s : %d -> %d", lc->setting.name, lc->setting.oldval, lc->setting.newval);
 264                                         break;
 265
 266                                 case GLCT_GRFADD: {
 267                                         const GRFConfig *gc = FindGRFConfig(lc->grfadd.grfid, FGCM_EXACT, lc->grfadd.md5sum);
 268                                         buf += seprintf(buf, lastof(buffer), "Added NewGRF: ");
 269                                         buf = PrintGrfInfo(buf, lastof(buffer), lc->grfadd.grfid, lc->grfadd.md5sum, gc);
 270                                         GrfIDMapping::Pair *gm = grf_names.Find(lc->grfrem.grfid);
 271                                         if (gm != grf_names.End() && !gm->second.was_missing) buf += seprintf(buf, lastof(buffer), ". Gamelog inconsistency: GrfID was already added!");
 272                                         grf_names[lc->grfadd.grfid] = gc;
 273                                         break;
 274                                 }
 275
 276                                 case GLCT_GRFREM: {
 277                                         GrfIDMapping::Pair *gm = grf_names.Find(lc->grfrem.grfid);
 278                                         buf += seprintf(buf, lastof(buffer), la->at == GLAT_LOAD ? "Missing NewGRF: " : "Removed NewGRF: ");
 279                                         buf = PrintGrfInfo(buf, lastof(buffer), lc->grfrem.grfid, nullptr, gm != grf_names.End() ? gm->second.gc : nullptr);
 280                                         if (gm == grf_names.End()) {
 281                                                 buf += seprintf(buf, lastof(buffer), ". Gamelog inconsistency: GrfID was never added!");
 282                                         } else {
 283                                                 if (la->at == GLAT_LOAD) {
 284                                                         /* Missing grfs on load are not removed from the configuration */
 285                                                         gm->second.was_missing = true;
 286                                                 } else {
 287                                                         grf_names.Erase(gm);
 288                                                 }
 289                                         }
 290                                         break;
 291                                 }
 292
 293                                 case GLCT_GRFCOMPAT: {
 294                                         const GRFConfig *gc = FindGRFConfig(lc->grfadd.grfid, FGCM_EXACT, lc->grfadd.md5sum);
 295                                         buf += seprintf(buf, lastof(buffer), "Compatible NewGRF loaded: ");
 296                                         buf = PrintGrfInfo(buf, lastof(buffer), lc->grfcompat.grfid, lc->grfcompat.md5sum, gc);
 297                                         if (!grf_names.Contains(lc->grfcompat.grfid)) buf += seprintf(buf, lastof(buffer), ". Gamelog inconsistency: GrfID was never added!");
 298                                         grf_names[lc->grfcompat.grfid] = gc;
 299                                         break;
 300                                 }
 301
 302                                 case GLCT_GRFPARAM: {
 303                                         GrfIDMapping::Pair *gm = grf_names.Find(lc->grfrem.grfid);
 304                                         buf += seprintf(buf, lastof(buffer), "GRF parameter changed: ");
 305                                         buf = PrintGrfInfo(buf, lastof(buffer), lc->grfparam.grfid, nullptr, gm != grf_names.End() ? gm->second.gc : nullptr);
 306                                         if (gm == grf_names.End()) buf += seprintf(buf, lastof(buffer), ". Gamelog inconsistency: GrfID was never added!");
 307                                         break;
 308                                 }
 309
 310                                 case GLCT_GRFMOVE: {
 311                                         GrfIDMapping::Pair *gm = grf_names.Find(lc->grfrem.grfid);
 312                                         buf += seprintf(buf, lastof(buffer), "GRF order changed: %08X moved %d places %s",
 313                                                 BSWAP32(lc->grfmove.grfid), abs(lc->grfmove.offset), lc->grfmove.offset >= 0 ? "down" : "up" );
 314                                         buf = PrintGrfInfo(buf, lastof(buffer), lc->grfmove.grfid, nullptr, gm != grf_names.End() ? gm->second.gc : nullptr);
 315                                         if (gm == grf_names.End()) buf += seprintf(buf, lastof(buffer), ". Gamelog inconsistency: GrfID was never added!");
 316                                         break;
 317                                 }
 318
 319                                 case GLCT_GRFBUG: {
 320                                         GrfIDMapping::Pair *gm = grf_names.Find(lc->grfrem.grfid);
 321                                         switch (lc->grfbug.bug) {
 322                                                 default: NOT_REACHED();
 323                                                 case GBUG_VEH_LENGTH:
 324                                                         buf += seprintf(buf, lastof(buffer), "Rail vehicle changes length outside a depot: GRF ID %08X, internal ID 0x%X", BSWAP32(lc->grfbug.grfid), (uint)lc->grfbug.data);
 325                                                         break;
 326                                         }
 327                                         buf = PrintGrfInfo(buf, lastof(buffer), lc->grfbug.grfid, nullptr, gm != grf_names.End() ? gm->second.gc : nullptr);
 328                                         if (gm == grf_names.End()) buf += seprintf(buf, lastof(buffer), ". Gamelog inconsistency: GrfID was never added!");
 329                                         break;
 330                                 }
 331
 332                                 case GLCT_EMERGENCY:
 333                                         break;
 334                         }
 335
 336                         proc(buffer);
 337                 }
 338         }
 339
 340         proc("---- gamelog end ----");
 341 }
 342
 343
 344 static void GamelogPrintConsoleProc(const char *s)
 345 {
 346         IConsolePrint(CC_WARNING, s);
 347 }
 348
 349 /** Print the gamelog data to the console. */
 350 void GamelogPrintConsole()
 351 {
 352         GamelogPrint(&GamelogPrintConsoleProc);
 353 }
 354
 355 static int _gamelog_print_level = 0; ///< gamelog debug level we need to print stuff
 356
 357 static void GamelogPrintDebugProc(const char *s)
 358 {
 359         Debug(gamelog, _gamelog_print_level, "{}", s);
 360 }
 361
 362
 363 /**
 364  * Prints gamelog to debug output. Code is executed even when
 365  * there will be no output. It is called very seldom, so it
 366  * doesn't matter that much. At least it gives more uniform code...
 367  * @param level debug level we need to print stuff
 368  */
 369 void GamelogPrintDebug(int level)
 370 {
 371         _gamelog_print_level = level;
 372         GamelogPrint(&GamelogPrintDebugProc);
 373 }
 374
 375
 376 /**
 377  * Allocates new LoggedChange and new LoggedAction if needed.
 378  * If there is no action active, nullptr is returned.
 379  * @param ct type of change
 380  * @return new LoggedChange, or nullptr if there is no action active
 381  */
 382 static LoggedChange *GamelogChange(GamelogChangeType ct)
 383 {
 384         if (_current_action == nullptr) {
 385                 if (_gamelog_action_type == GLAT_NONE) return nullptr;
 386
 387                 _gamelog_action  = ReallocT(_gamelog_action, _gamelog_actions + 1);
 388                 _current_action  = &_gamelog_action[_gamelog_actions++];
 389
 390                 _current_action->at      = _gamelog_action_type;
 391                 _current_action->tick    = _tick_counter;
 392                 _current_action->change  = nullptr;
 393                 _current_action->changes = 0;
 394         }
 395
 396         _current_action->change = ReallocT(_current_action->change, _current_action->changes + 1);
 397
 398         LoggedChange *lc = &_current_action->change[_current_action->changes++];
 399         lc->ct = ct;
 400
 401         return lc;
 402 }
 403
 404
 405 /**
 406  * Logs a emergency savegame
 407  */
 408 void GamelogEmergency()
 409 {
 410         /* Terminate any active action */
 411         if (_gamelog_action_type != GLAT_NONE) GamelogStopAction();
 412         GamelogStartAction(GLAT_EMERGENCY);
 413         GamelogChange(GLCT_EMERGENCY);
 414         GamelogStopAction();
 415 }
 416
 417 /**
 418  * Finds out if current game is a loaded emergency savegame.
 419  */
 420 bool GamelogTestEmergency()
 421 {
 422         const LoggedChange *emergency = nullptr;
 423
 424         const LoggedAction *laend = &_gamelog_action[_gamelog_actions];
 425         for (const LoggedAction *la = _gamelog_action; la != laend; la++) {
 426                 const LoggedChange *lcend = &la->change[la->changes];
 427                 for (const LoggedChange *lc = la->change; lc != lcend; lc++) {
 428                         if (lc->ct == GLCT_EMERGENCY) emergency = lc;
 429                 }
 430         }
 431
 432         return (emergency != nullptr);
 433 }
 434
 435 /**
 436  * Logs a change in game revision
 437  */
 438 void GamelogRevision()
 439 {
 440         assert(_gamelog_action_type == GLAT_START || _gamelog_action_type == GLAT_LOAD);
 441
 442         LoggedChange *lc = GamelogChange(GLCT_REVISION);
 443         if (lc == nullptr) return;
 444
 445         memset(lc->revision.text, 0, sizeof(lc->revision.text));
 446         strecpy(lc->revision.text, GetGamelogRevisionString(), lastof(lc->revision.text));
 447         lc->revision.slver = SAVEGAME_VERSION;
 448         lc->revision.modified = _openttd_revision_modified;
 449         lc->revision.newgrf = _openttd_newgrf_version;
 450 }
 451
 452 /**
 453  * Logs a change in game mode (scenario editor or game)
 454  */
 455 void GamelogMode()
 456 {
 457         assert(_gamelog_action_type == GLAT_START || _gamelog_action_type == GLAT_LOAD || _gamelog_action_type == GLAT_CHEAT);
 458
 459         LoggedChange *lc = GamelogChange(GLCT_MODE);
 460         if (lc == nullptr) return;
 461
 462         lc->mode.mode      = _game_mode;
 463         lc->mode.landscape = _settings_game.game_creation.landscape;
 464 }
 465
 466 /**
 467  * Logs loading from savegame without gamelog
 468  */
 469 void GamelogOldver()
 470 {
 471         assert(_gamelog_action_type == GLAT_LOAD);
 472
 473         LoggedChange *lc = GamelogChange(GLCT_OLDVER);
 474         if (lc == nullptr) return;
 475
 476         lc->oldver.type = _savegame_type;
 477         lc->oldver.version = (_savegame_type == SGT_OTTD ? ((uint32)_sl_version << 8 | _sl_minor_version) : _ttdp_version);
 478 }
 479
 480 /**
 481  * Logs change in game settings. Only non-networksafe settings are logged
 482  * @param name setting name
 483  * @param oldval old setting value
 484  * @param newval new setting value
 485  */
 486 void GamelogSetting(const std::string &name, int32 oldval, int32 newval)
 487 {
 488         assert(_gamelog_action_type == GLAT_SETTING);
 489
 490         LoggedChange *lc = GamelogChange(GLCT_SETTING);
 491         if (lc == nullptr) return;
 492
 493         lc->setting.name = stredup(name.c_str());
 494         lc->setting.oldval = oldval;
 495         lc->setting.newval = newval;
 496 }
 497
 498
 499 /**
 500  * Finds out if current revision is different than last revision stored in the savegame.
 501  * Appends GLCT_REVISION when the revision string changed
 502  */
 503 void GamelogTestRevision()
 504 {
 505         const LoggedChange *rev = nullptr;
 506
 507         const LoggedAction *laend = &_gamelog_action[_gamelog_actions];
 508         for (const LoggedAction *la = _gamelog_action; la != laend; la++) {
 509                 const LoggedChange *lcend = &la->change[la->changes];
 510                 for (const LoggedChange *lc = la->change; lc != lcend; lc++) {
 511                         if (lc->ct == GLCT_REVISION) rev = lc;
 512                 }
 513         }
 514
 515         if (rev == nullptr || strcmp(rev->revision.text, GetGamelogRevisionString()) != 0 ||
 516                         rev->revision.modified != _openttd_revision_modified ||
 517                         rev->revision.newgrf != _openttd_newgrf_version) {
 518                 GamelogRevision();
 519         }
 520 }
 521
 522 /**
 523  * Finds last stored game mode or landscape.
 524  * Any change is logged
 525  */
 526 void GamelogTestMode()
 527 {
 528         const LoggedChange *mode = nullptr;
 529
 530         const LoggedAction *laend = &_gamelog_action[_gamelog_actions];
 531         for (const LoggedAction *la = _gamelog_action; la != laend; la++) {
 532                 const LoggedChange *lcend = &la->change[la->changes];
 533                 for (const LoggedChange *lc = la->change; lc != lcend; lc++) {
 534                         if (lc->ct == GLCT_MODE) mode = lc;
 535                 }
 536         }
 537
 538         if (mode == nullptr || mode->mode.mode != _game_mode || mode->mode.landscape != _settings_game.game_creation.landscape) GamelogMode();
 539 }
 540
 541
 542 /**
 543  * Logs triggered GRF bug.
 544  * @param grfid ID of problematic GRF
 545  * @param bug type of bug, @see enum GRFBugs
 546  * @param data additional data
 547  */
 548 static void GamelogGRFBug(uint32 grfid, byte bug, uint64 data)
 549 {
 550         assert(_gamelog_action_type == GLAT_GRFBUG);
 551
 552         LoggedChange *lc = GamelogChange(GLCT_GRFBUG);
 553         if (lc == nullptr) return;
 554
 555         lc->grfbug.data  = data;
 556         lc->grfbug.grfid = grfid;
 557         lc->grfbug.bug   = bug;
 558 }
 559
 560 /**
 561  * Logs GRF bug - rail vehicle has different length after reversing.
 562  * Ensures this is logged only once for each GRF and engine type
 563  * This check takes some time, but it is called pretty seldom, so it
 564  * doesn't matter that much (ideally it shouldn't be called at all).
 565  * @param grfid the broken NewGRF
 566  * @param internal_id the internal ID of whatever's broken in the NewGRF
 567  * @return true iff a unique record was done
 568  */
 569 bool GamelogGRFBugReverse(uint32 grfid, uint16 internal_id)
 570 {
 571         const LoggedAction *laend = &_gamelog_action[_gamelog_actions];
 572         for (const LoggedAction *la = _gamelog_action; la != laend; la++) {
 573                 const LoggedChange *lcend = &la->change[la->changes];
 574                 for (const LoggedChange *lc = la->change; lc != lcend; lc++) {
 575                         if (lc->ct == GLCT_GRFBUG && lc->grfbug.grfid == grfid &&
 576                                         lc->grfbug.bug == GBUG_VEH_LENGTH && lc->grfbug.data == internal_id) {
 577                                 return false;
 578                         }
 579                 }
 580         }
 581
 582         GamelogStartAction(GLAT_GRFBUG);
 583         GamelogGRFBug(grfid, GBUG_VEH_LENGTH, internal_id);
 584         GamelogStopAction();
 585
 586         return true;
 587 }
 588
 589
 590 /**
 591  * Decides if GRF should be logged
 592  * @param g grf to determine
 593  * @return true iff GRF is not static and is loaded
 594  */
 595 static inline bool IsLoggableGrfConfig(const GRFConfig *g)
 596 {
 597         return !HasBit(g->flags, GCF_STATIC) && g->status != GCS_NOT_FOUND;
 598 }
 599
 600 /**
 601  * Logs removal of a GRF
 602  * @param grfid ID of removed GRF
 603  */
 604 void GamelogGRFRemove(uint32 grfid)
 605 {
 606         assert(_gamelog_action_type == GLAT_LOAD || _gamelog_action_type == GLAT_GRF);
 607
 608         LoggedChange *lc = GamelogChange(GLCT_GRFREM);
 609         if (lc == nullptr) return;
 610
 611         lc->grfrem.grfid = grfid;
 612 }
 613
 614 /**
 615  * Logs adding of a GRF
 616  * @param newg added GRF
 617  */
 618 void GamelogGRFAdd(const GRFConfig *newg)
 619 {
 620         assert(_gamelog_action_type == GLAT_LOAD || _gamelog_action_type == GLAT_START || _gamelog_action_type == GLAT_GRF);
 621
 622         if (!IsLoggableGrfConfig(newg)) return;
 623
 624         LoggedChange *lc = GamelogChange(GLCT_GRFADD);
 625         if (lc == nullptr) return;
 626
 627         lc->grfadd = newg->ident;
 628 }
 629
 630 /**
 631  * Logs loading compatible GRF
 632  * (the same ID, but different MD5 hash)
 633  * @param newg new (updated) GRF
 634  */
 635 void GamelogGRFCompatible(const GRFIdentifier *newg)
 636 {
 637         assert(_gamelog_action_type == GLAT_LOAD || _gamelog_action_type == GLAT_GRF);
 638
 639         LoggedChange *lc = GamelogChange(GLCT_GRFCOMPAT);
 640         if (lc == nullptr) return;
 641
 642         lc->grfcompat = *newg;
 643 }
 644
 645 /**
 646  * Logs changing GRF order
 647  * @param grfid GRF that is moved
 648  * @param offset how far it is moved, positive = moved down
 649  */
 650 static void GamelogGRFMove(uint32 grfid, int32 offset)
 651 {
 652         assert(_gamelog_action_type == GLAT_GRF);
 653
 654         LoggedChange *lc = GamelogChange(GLCT_GRFMOVE);
 655         if (lc == nullptr) return;
 656
 657         lc->grfmove.grfid  = grfid;
 658         lc->grfmove.offset = offset;
 659 }
 660
 661 /**
 662  * Logs change in GRF parameters.
 663  * Details about parameters changed are not stored
 664  * @param grfid ID of GRF to store
 665  */
 666 static void GamelogGRFParameters(uint32 grfid)
 667 {
 668         assert(_gamelog_action_type == GLAT_GRF);
 669
 670         LoggedChange *lc = GamelogChange(GLCT_GRFPARAM);
 671         if (lc == nullptr) return;
 672
 673         lc->grfparam.grfid = grfid;
 674 }
 675
 676 /**
 677  * Logs adding of list of GRFs.
 678  * Useful when old savegame is loaded or when new game is started
 679  * @param newg head of GRF linked list
 680  */
 681 void GamelogGRFAddList(const GRFConfig *newg)
 682 {
 683         assert(_gamelog_action_type == GLAT_START || _gamelog_action_type == GLAT_LOAD);
 684
 685         for (; newg != nullptr; newg = newg->next) {
 686                 GamelogGRFAdd(newg);
 687         }
 688 }
 689
 690 /** List of GRFs using array of pointers instead of linked list */
 691 struct GRFList {
 692         uint n;
 693         const GRFConfig *grf[];
 694 };
 695
 696 /**
 697  * Generates GRFList
 698  * @param grfc head of GRF linked list
 699  */
 700 static GRFList *GenerateGRFList(const GRFConfig *grfc)
 701 {
 702         uint n = 0;
 703         for (const GRFConfig *g = grfc; g != nullptr; g = g->next) {
 704                 if (IsLoggableGrfConfig(g)) n++;
 705         }
 706
 707         GRFList *list = (GRFList*)MallocT<byte>(sizeof(GRFList) + n * sizeof(GRFConfig*));
 708
 709         list->n = 0;
 710         for (const GRFConfig *g = grfc; g != nullptr; g = g->next) {
 711                 if (IsLoggableGrfConfig(g)) list->grf[list->n++] = g;
 712         }
 713
 714         return list;
 715 }
 716
 717 /**
 718  * Compares two NewGRF lists and logs any change
 719  * @param oldc original GRF list
 720  * @param newc new GRF list
 721  */
 722 void GamelogGRFUpdate(const GRFConfig *oldc, const GRFConfig *newc)
 723 {
 724         GRFList *ol = GenerateGRFList(oldc);
 725         GRFList *nl = GenerateGRFList(newc);
 726
 727         uint o = 0, n = 0;
 728
 729         while (o < ol->n && n < nl->n) {
 730                 const GRFConfig *og = ol->grf[o];
 731                 const GRFConfig *ng = nl->grf[n];
 732
 733                 if (og->ident.grfid != ng->ident.grfid) {
 734                         uint oi, ni;
 735                         for (oi = 0; oi < ol->n; oi++) {
 736                                 if (ol->grf[oi]->ident.grfid == nl->grf[n]->ident.grfid) break;
 737                         }
 738                         if (oi < o) {
 739                                 /* GRF was moved, this change has been logged already */
 740                                 n++;
 741                                 continue;
 742                         }
 743                         if (oi == ol->n) {
 744                                 /* GRF couldn't be found in the OLD list, GRF was ADDED */
 745                                 GamelogGRFAdd(nl->grf[n++]);
 746                                 continue;
 747                         }
 748                         for (ni = 0; ni < nl->n; ni++) {
 749                                 if (nl->grf[ni]->ident.grfid == ol->grf[o]->ident.grfid) break;
 750                         }
 751                         if (ni < n) {
 752                                 /* GRF was moved, this change has been logged already */
 753                                 o++;
 754                                 continue;
 755                         }
 756                         if (ni == nl->n) {
 757                                 /* GRF couldn't be found in the NEW list, GRF was REMOVED */
 758                                 GamelogGRFRemove(ol->grf[o++]->ident.grfid);
 759                                 continue;
 760                         }
 761
 762                         /* o < oi < ol->n
 763                          * n < ni < nl->n */
 764                         assert(ni > n && ni < nl->n);
 765                         assert(oi > o && oi < ol->n);
 766
 767                         ni -= n; // number of GRFs it was moved downwards
 768                         oi -= o; // number of GRFs it was moved upwards
 769
 770                         if (ni >= oi) { // prefer the one that is moved further
 771                                 /* GRF was moved down */
 772                                 GamelogGRFMove(ol->grf[o++]->ident.grfid, ni);
 773                         } else {
 774                                 GamelogGRFMove(nl->grf[n++]->ident.grfid, -(int)oi);
 775                         }
 776                 } else {
 777                         if (memcmp(og->ident.md5sum, ng->ident.md5sum, sizeof(og->ident.md5sum)) != 0) {
 778                                 /* md5sum changed, probably loading 'compatible' GRF */
 779                                 GamelogGRFCompatible(&nl->grf[n]->ident);
 780                         }
 781
 782                         if (og->num_params != ng->num_params || memcmp(og->param, ng->param, og->num_params * sizeof(og->param[0])) != 0) {
 783                                 GamelogGRFParameters(ol->grf[o]->ident.grfid);
 784                         }
 785
 786                         o++;
 787                         n++;
 788                 }
 789         }
 790
 791         while (o < ol->n) GamelogGRFRemove(ol->grf[o++]->ident.grfid); // remaining GRFs were removed ...
 792         while (n < nl->n) GamelogGRFAdd   (nl->grf[n++]);              // ... or added
 793
 794         free(ol);
 795         free(nl);
 796 }
 797
 798 /**
 799  * Get some basic information from the given gamelog.
 800  * @param gamelog_action Pointer to the gamelog to extract information from.
 801  * @param gamelog_actions Number of actions in the given gamelog.
 802  * @param[out] last_ottd_rev OpenTTD NewGRF version from the binary that saved the savegame last.
 803  * @param[out] ever_modified Max value of 'modified' from all binaries that ever saved this savegame.
 804  * @param[out] removed_newgrfs Set to true if any NewGRFs have been removed.
 805  */
 806 void GamelogInfo(LoggedAction *gamelog_action, uint gamelog_actions, uint32 *last_ottd_rev, byte *ever_modified, bool *removed_newgrfs)
 807 {
 808         const LoggedAction *laend = &gamelog_action[gamelog_actions];
 809         for (const LoggedAction *la = gamelog_action; la != laend; la++) {
 810                 const LoggedChange *lcend = &la->change[la->changes];
 811                 for (const LoggedChange *lc = la->change; lc != lcend; lc++) {
 812                         switch (lc->ct) {
 813                                 default: break;
 814
 815                                 case GLCT_REVISION:
 816                                         *last_ottd_rev = lc->revision.newgrf;
 817                                         *ever_modified = std::max(*ever_modified, lc->revision.modified);
 818                                         break;
 819
 820                                 case GLCT_GRFREM:
 821                                         *removed_newgrfs = true;
 822                                         break;
 823                         }
 824                 }
 825         }
 826 }