src/script/squirrel.cpp

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * 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.
   6  * 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.
   7  * 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/>.
   8  */
   9
  10 /** @file squirrel.cpp the implementation of the Squirrel class. It handles all Squirrel-stuff and gives a nice API back to work with. */
  11
  12 #include <stdarg.h>
  13 #include "../stdafx.h"
  14 #include "../debug.h"
  15 #include "squirrel_std.hpp"
  16 #include "../fileio_func.h"
  17 #include "../string_func.h"
  18 #include <sqstdaux.h>
  19 #include <../squirrel/sqpcheader.h>
  20 #include <../squirrel/sqvm.h>
  21
  22 #include "../safeguards.h"
  23
  24 void Squirrel::CompileError(HSQUIRRELVM vm, const SQChar *desc, const SQChar *source, SQInteger line, SQInteger column)
  25 {
  26         SQChar buf[1024];
  27
  28         seprintf(buf, lastof(buf), "Error %s:" OTTD_PRINTF64 "/" OTTD_PRINTF64 ": %s", source, line, column, desc);
  29
  30         /* Check if we have a custom print function */
  31         Squirrel *engine = (Squirrel *)sq_getforeignptr(vm);
  32         engine->crashed = true;
  33         SQPrintFunc *func = engine->print_func;
  34         if (func == NULL) {
  35                 DEBUG(misc, 0, "[Squirrel] Compile error: %s", buf);
  36         } else {
  37                 (*func)(true, buf);
  38         }
  39 }
  40
  41 void Squirrel::ErrorPrintFunc(HSQUIRRELVM vm, const SQChar *s, ...)
  42 {
  43         va_list arglist;
  44         SQChar buf[1024];
  45
  46         va_start(arglist, s);
  47         vseprintf(buf, lastof(buf), s, arglist);
  48         va_end(arglist);
  49
  50         /* Check if we have a custom print function */
  51         SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;
  52         if (func == NULL) {
  53                 fprintf(stderr, "%s", buf);
  54         } else {
  55                 (*func)(true, buf);
  56         }
  57 }
  58
  59 void Squirrel::RunError(HSQUIRRELVM vm, const SQChar *error)
  60 {
  61         /* Set the print function to something that prints to stderr */
  62         SQPRINTFUNCTION pf = sq_getprintfunc(vm);
  63         sq_setprintfunc(vm, &Squirrel::ErrorPrintFunc);
  64
  65         /* Check if we have a custom print function */
  66         SQChar buf[1024];
  67         seprintf(buf, lastof(buf), "Your script made an error: %s\n", error);
  68         Squirrel *engine = (Squirrel *)sq_getforeignptr(vm);
  69         SQPrintFunc *func = engine->print_func;
  70         if (func == NULL) {
  71                 fprintf(stderr, "%s", buf);
  72         } else {
  73                 (*func)(true, buf);
  74         }
  75
  76         /* Print below the error the stack, so the users knows what is happening */
  77         sqstd_printcallstack(vm);
  78         /* Reset the old print function */
  79         sq_setprintfunc(vm, pf);
  80 }
  81
  82 SQInteger Squirrel::_RunError(HSQUIRRELVM vm)
  83 {
  84         const SQChar *sErr = 0;
  85
  86         if (sq_gettop(vm) >= 1) {
  87                 if (SQ_SUCCEEDED(sq_getstring(vm, -1, &sErr))) {
  88                         Squirrel::RunError(vm, sErr);
  89                         return 0;
  90                 }
  91         }
  92
  93         Squirrel::RunError(vm, "unknown error");
  94         return 0;
  95 }
  96
  97 void Squirrel::PrintFunc(HSQUIRRELVM vm, const SQChar *s, ...)
  98 {
  99         va_list arglist;
 100         SQChar buf[1024];
 101
 102         va_start(arglist, s);
 103         vseprintf(buf, lastof(buf) - 2, s, arglist);
 104         va_end(arglist);
 105         strecat(buf, "\n", lastof(buf));
 106
 107         /* Check if we have a custom print function */
 108         SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;
 109         if (func == NULL) {
 110                 printf("%s", buf);
 111         } else {
 112                 (*func)(false, buf);
 113         }
 114 }
 115
 116 void Squirrel::AddMethod(const char *method_name, SQFUNCTION proc, uint nparam, const char *params, void *userdata, int size)
 117 {
 118         sq_pushstring(this->vm, method_name, -1);
 119
 120         if (size != 0) {
 121                 void *ptr = sq_newuserdata(vm, size);
 122                 memcpy(ptr, userdata, size);
 123         }
 124
 125         sq_newclosure(this->vm, proc, size != 0 ? 1 : 0);
 126         if (nparam != 0) sq_setparamscheck(this->vm, nparam, params);
 127         sq_setnativeclosurename(this->vm, -1, method_name);
 128         sq_newslot(this->vm, -3, SQFalse);
 129 }
 130
 131 void Squirrel::AddConst(const char *var_name, int value)
 132 {
 133         sq_pushstring(this->vm, var_name, -1);
 134         sq_pushinteger(this->vm, value);
 135         sq_newslot(this->vm, -3, SQTrue);
 136 }
 137
 138 void Squirrel::AddConst(const char *var_name, bool value)
 139 {
 140         sq_pushstring(this->vm, var_name, -1);
 141         sq_pushbool(this->vm, value);
 142         sq_newslot(this->vm, -3, SQTrue);
 143 }
 144
 145 void Squirrel::AddClassBegin(const char *class_name)
 146 {
 147         sq_pushroottable(this->vm);
 148         sq_pushstring(this->vm, class_name, -1);
 149         sq_newclass(this->vm, SQFalse);
 150 }
 151
 152 void Squirrel::AddClassBegin(const char *class_name, const char *parent_class)
 153 {
 154         sq_pushroottable(this->vm);
 155         sq_pushstring(this->vm, class_name, -1);
 156         sq_pushstring(this->vm, parent_class, -1);
 157         if (SQ_FAILED(sq_get(this->vm, -3))) {
 158                 DEBUG(misc, 0, "[squirrel] Failed to initialize class '%s' based on parent class '%s'", class_name, parent_class);
 159                 DEBUG(misc, 0, "[squirrel] Make sure that '%s' exists before trying to define '%s'", parent_class, class_name);
 160                 return;
 161         }
 162         sq_newclass(this->vm, SQTrue);
 163 }
 164
 165 void Squirrel::AddClassEnd()
 166 {
 167         sq_newslot(vm, -3, SQFalse);
 168         sq_pop(vm, 1);
 169 }
 170
 171 bool Squirrel::MethodExists(HSQOBJECT instance, const char *method_name)
 172 {
 173         assert(!this->crashed);
 174         int top = sq_gettop(this->vm);
 175         /* Go to the instance-root */
 176         sq_pushobject(this->vm, instance);
 177         /* Find the function-name inside the script */
 178         sq_pushstring(this->vm, method_name, -1);
 179         if (SQ_FAILED(sq_get(this->vm, -2))) {
 180                 sq_settop(this->vm, top);
 181                 return false;
 182         }
 183         sq_settop(this->vm, top);
 184         return true;
 185 }
 186
 187 bool Squirrel::Resume(int suspend)
 188 {
 189         assert(!this->crashed);
 190         /* Did we use more operations than we should have in the
 191          * previous tick? If so, subtract that from the current run. */
 192         if (this->overdrawn_ops > 0 && suspend > 0) {
 193                 this->overdrawn_ops -= suspend;
 194                 /* Do we need to wait even more? */
 195                 if (this->overdrawn_ops >= 0) return true;
 196
 197                 /* We can now only run whatever is "left". */
 198                 suspend = -this->overdrawn_ops;
 199         }
 200
 201         this->crashed = !sq_resumecatch(this->vm, suspend);
 202         this->overdrawn_ops = -this->vm->_ops_till_suspend;
 203         return this->vm->_suspended != 0;
 204 }
 205
 206 void Squirrel::ResumeError()
 207 {
 208         assert(!this->crashed);
 209         sq_resumeerror(this->vm);
 210 }
 211
 212 void Squirrel::CollectGarbage()
 213 {
 214         sq_collectgarbage(this->vm);
 215 }
 216
 217 bool Squirrel::CallMethod(HSQOBJECT instance, const char *method_name, HSQOBJECT *ret, int suspend)
 218 {
 219         assert(!this->crashed);
 220         /* Store the stack-location for the return value. We need to
 221          * restore this after saving or the stack will be corrupted
 222          * if we're in the middle of a DoCommand. */
 223         SQInteger last_target = this->vm->_suspended_target;
 224         /* Store the current top */
 225         int top = sq_gettop(this->vm);
 226         /* Go to the instance-root */
 227         sq_pushobject(this->vm, instance);
 228         /* Find the function-name inside the script */
 229         sq_pushstring(this->vm, method_name, -1);
 230         if (SQ_FAILED(sq_get(this->vm, -2))) {
 231                 DEBUG(misc, 0, "[squirrel] Could not find '%s' in the class", method_name);
 232                 sq_settop(this->vm, top);
 233                 return false;
 234         }
 235         /* Call the method */
 236         sq_pushobject(this->vm, instance);
 237         if (SQ_FAILED(sq_call(this->vm, 1, ret == NULL ? SQFalse : SQTrue, SQTrue, suspend))) return false;
 238         if (ret != NULL) sq_getstackobj(vm, -1, ret);
 239         /* Reset the top, but don't do so for the script main function, as we need
 240          *  a correct stack when resuming. */
 241         if (suspend == -1 || !this->IsSuspended()) sq_settop(this->vm, top);
 242         /* Restore the return-value location. */
 243         this->vm->_suspended_target = last_target;
 244
 245         return true;
 246 }
 247
 248 bool Squirrel::CallStringMethodStrdup(HSQOBJECT instance, const char *method_name, const char **res, int suspend)
 249 {
 250         HSQOBJECT ret;
 251         if (!this->CallMethod(instance, method_name, &ret, suspend)) return false;
 252         if (ret._type != OT_STRING) return false;
 253         *res = stredup(ObjectToString(&ret));
 254         ValidateString(*res);
 255         return true;
 256 }
 257
 258 bool Squirrel::CallIntegerMethod(HSQOBJECT instance, const char *method_name, int *res, int suspend)
 259 {
 260         HSQOBJECT ret;
 261         if (!this->CallMethod(instance, method_name, &ret, suspend)) return false;
 262         if (ret._type != OT_INTEGER) return false;
 263         *res = ObjectToInteger(&ret);
 264         return true;
 265 }
 266
 267 bool Squirrel::CallBoolMethod(HSQOBJECT instance, const char *method_name, bool *res, int suspend)
 268 {
 269         HSQOBJECT ret;
 270         if (!this->CallMethod(instance, method_name, &ret, suspend)) return false;
 271         if (ret._type != OT_BOOL) return false;
 272         *res = ObjectToBool(&ret);
 273         return true;
 274 }
 275
 276 /* static */ bool Squirrel::CreateClassInstanceVM(HSQUIRRELVM vm, const char *class_name, void *real_instance, HSQOBJECT *instance, SQRELEASEHOOK release_hook, bool prepend_API_name)
 277 {
 278         Squirrel *engine = (Squirrel *)sq_getforeignptr(vm);
 279
 280         int oldtop = sq_gettop(vm);
 281
 282         /* First, find the class */
 283         sq_pushroottable(vm);
 284
 285         if (prepend_API_name) {
 286                 size_t len = strlen(class_name) + strlen(engine->GetAPIName()) + 1;
 287                 char *class_name2 = (char *)alloca(len);
 288                 seprintf(class_name2, class_name2 + len - 1, "%s%s", engine->GetAPIName(), class_name);
 289
 290                 sq_pushstring(vm, class_name2, -1);
 291         } else {
 292                 sq_pushstring(vm, class_name, -1);
 293         }
 294
 295         if (SQ_FAILED(sq_get(vm, -2))) {
 296                 DEBUG(misc, 0, "[squirrel] Failed to find class by the name '%s%s'", prepend_API_name ? engine->GetAPIName() : "", class_name);
 297                 sq_settop(vm, oldtop);
 298                 return false;
 299         }
 300
 301         /* Create the instance */
 302         if (SQ_FAILED(sq_createinstance(vm, -1))) {
 303                 DEBUG(misc, 0, "[squirrel] Failed to create instance for class '%s%s'", prepend_API_name ? engine->GetAPIName() : "", class_name);
 304                 sq_settop(vm, oldtop);
 305                 return false;
 306         }
 307
 308         if (instance != NULL) {
 309                 /* Find our instance */
 310                 sq_getstackobj(vm, -1, instance);
 311                 /* Add a reference to it, so it survives for ever */
 312                 sq_addref(vm, instance);
 313         }
 314         sq_remove(vm, -2); // Class-name
 315         sq_remove(vm, -2); // Root-table
 316
 317         /* Store it in the class */
 318         sq_setinstanceup(vm, -1, real_instance);
 319         if (release_hook != NULL) sq_setreleasehook(vm, -1, release_hook);
 320
 321         if (instance != NULL) sq_settop(vm, oldtop);
 322
 323         return true;
 324 }
 325
 326 bool Squirrel::CreateClassInstance(const char *class_name, void *real_instance, HSQOBJECT *instance)
 327 {
 328         return Squirrel::CreateClassInstanceVM(this->vm, class_name, real_instance, instance, NULL);
 329 }
 330
 331 Squirrel::Squirrel(const char *APIName) :
 332         APIName(APIName)
 333 {
 334         this->Initialize();
 335 }
 336
 337 void Squirrel::Initialize()
 338 {
 339         this->global_pointer = NULL;
 340         this->print_func = NULL;
 341         this->crashed = false;
 342         this->overdrawn_ops = 0;
 343         this->vm = sq_open(1024);
 344
 345         /* Handle compile-errors ourself, so we can display it nicely */
 346         sq_setcompilererrorhandler(this->vm, &Squirrel::CompileError);
 347         sq_notifyallexceptions(this->vm, SQTrue);
 348         /* Set a good print-function */
 349         sq_setprintfunc(this->vm, &Squirrel::PrintFunc);
 350         /* Handle runtime-errors ourself, so we can display it nicely */
 351         sq_newclosure(this->vm, &Squirrel::_RunError, 0);
 352         sq_seterrorhandler(this->vm);
 353
 354         /* Set the foreign pointer, so we can always find this instance from within the VM */
 355         sq_setforeignptr(this->vm, this);
 356
 357         sq_pushroottable(this->vm);
 358         squirrel_register_global_std(this);
 359 }
 360
 361 class SQFile {
 362 private:
 363         FILE *file;
 364         size_t size;
 365         size_t pos;
 366
 367 public:
 368         SQFile(FILE *file, size_t size) : file(file), size(size), pos(0) {}
 369
 370         size_t Read(void *buf, size_t elemsize, size_t count)
 371         {
 372                 assert(elemsize != 0);
 373                 if (this->pos + (elemsize * count) > this->size) {
 374                         count = (this->size - this->pos) / elemsize;
 375                 }
 376                 if (count == 0) return 0;
 377                 size_t ret = fread(buf, elemsize, count, this->file);
 378                 this->pos += ret * elemsize;
 379                 return ret;
 380         }
 381 };
 382
 383 static WChar _io_file_lexfeed_ASCII(SQUserPointer file)
 384 {
 385         unsigned char c;
 386         if (((SQFile *)file)->Read(&c, sizeof(c), 1) > 0) return c;
 387         return 0;
 388 }
 389
 390 static WChar _io_file_lexfeed_UTF8(SQUserPointer file)
 391 {
 392         char buffer[5];
 393
 394         /* Read the first character, and get the length based on UTF-8 specs. If invalid, bail out. */
 395         if (((SQFile *)file)->Read(buffer, sizeof(buffer[0]), 1) != 1) return 0;
 396         uint len = Utf8EncodedCharLen(buffer[0]);
 397         if (len == 0) return -1;
 398
 399         /* Read the remaining bits. */
 400         if (len > 1 && ((SQFile *)file)->Read(buffer + 1, sizeof(buffer[0]), len - 1) != len - 1) return 0;
 401
 402         /* Convert the character, and when definitely invalid, bail out as well. */
 403         WChar c;
 404         if (Utf8Decode(&c, buffer) != len) return -1;
 405
 406         return c;
 407 }
 408
 409 static WChar _io_file_lexfeed_UCS2_no_swap(SQUserPointer file)
 410 {
 411         unsigned short c;
 412         if (((SQFile *)file)->Read(&c, sizeof(c), 1) > 0) return (WChar)c;
 413         return 0;
 414 }
 415
 416 static WChar _io_file_lexfeed_UCS2_swap(SQUserPointer file)
 417 {
 418         unsigned short c;
 419         if (((SQFile *)file)->Read(&c, sizeof(c), 1) > 0) {
 420                 c = ((c >> 8) & 0x00FF)| ((c << 8) & 0xFF00);
 421                 return (WChar)c;
 422         }
 423         return 0;
 424 }
 425
 426 static SQInteger _io_file_read(SQUserPointer file, SQUserPointer buf, SQInteger size)
 427 {
 428         SQInteger ret = ((SQFile *)file)->Read(buf, 1, size);
 429         if (ret == 0) return -1;
 430         return ret;
 431 }
 432
 433 SQRESULT Squirrel::LoadFile(HSQUIRRELVM vm, const char *filename, SQBool printerror)
 434 {
 435         size_t size;
 436         FILE *file;
 437         SQInteger ret;
 438         unsigned short us;
 439         unsigned char uc;
 440         SQLEXREADFUNC func;
 441
 442         if (strncmp(this->GetAPIName(), "AI", 2) == 0) {
 443                 file = FioFOpenFile(filename, "rb", AI_DIR, &size);
 444                 if (file == NULL) file = FioFOpenFile(filename, "rb", AI_LIBRARY_DIR, &size);
 445         } else if (strncmp(this->GetAPIName(), "GS", 2) == 0) {
 446                 file = FioFOpenFile(filename, "rb", GAME_DIR, &size);
 447                 if (file == NULL) file = FioFOpenFile(filename, "rb", GAME_LIBRARY_DIR, &size);
 448         } else {
 449                 NOT_REACHED();
 450         }
 451
 452         if (file != NULL) {
 453                 SQFile f(file, size);
 454                 ret = fread(&us, 1, sizeof(us), file);
 455                 /* Most likely an empty file */
 456                 if (ret != 2) us = 0;
 457
 458                 switch (us) {
 459                         case SQ_BYTECODE_STREAM_TAG: { // BYTECODE
 460                                 if (fseek(file, -2, SEEK_CUR) < 0) {
 461                                         FioFCloseFile(file);
 462                                         return sq_throwerror(vm, "cannot seek the file");
 463                                 }
 464                                 if (SQ_SUCCEEDED(sq_readclosure(vm, _io_file_read, &f))) {
 465                                         FioFCloseFile(file);
 466                                         return SQ_OK;
 467                                 }
 468                                 FioFCloseFile(file);
 469                                 return sq_throwerror(vm, "Couldn't read bytecode");
 470                         }
 471                         case 0xFFFE:
 472                                 /* Either this file is encoded as big-endian and we're on a little-endian
 473                                  * machine, or this file is encoded as little-endian and we're on a big-endian
 474                                  * machine. Either way, swap the bytes of every word we read. */
 475                                 func = _io_file_lexfeed_UCS2_swap;
 476                                 break;
 477                         case 0xFEFF: func = _io_file_lexfeed_UCS2_no_swap; break;
 478                         case 0xBBEF: // UTF-8
 479                         case 0xEFBB: // UTF-8 on big-endian machine
 480                                 if (fread(&uc, 1, sizeof(uc), file) == 0) {
 481                                         FioFCloseFile(file);
 482                                         return sq_throwerror(vm, "I/O error");
 483                                 }
 484                                 if (uc != 0xBF) {
 485                                         FioFCloseFile(file);
 486                                         return sq_throwerror(vm, "Unrecognized encoding");
 487                                 }
 488                                 func = _io_file_lexfeed_UTF8;
 489                                 break;
 490                         default: // ASCII
 491                                 func = _io_file_lexfeed_ASCII;
 492                                 if (fseek(file, -2, SEEK_CUR) < 0) {
 493                                         FioFCloseFile(file);
 494                                         return sq_throwerror(vm, "cannot seek the file");
 495                                 }
 496                                 break;
 497                 }
 498
 499                 if (SQ_SUCCEEDED(sq_compile(vm, func, &f, filename, printerror))) {
 500                         FioFCloseFile(file);
 501                         return SQ_OK;
 502                 }
 503                 FioFCloseFile(file);
 504                 return SQ_ERROR;
 505         }
 506         return sq_throwerror(vm, "cannot open the file");
 507 }
 508
 509 bool Squirrel::LoadScript(HSQUIRRELVM vm, const char *script, bool in_root)
 510 {
 511         /* Make sure we are always in the root-table */
 512         if (in_root) sq_pushroottable(vm);
 513
 514         SQInteger ops_left = vm->_ops_till_suspend;
 515         /* Load and run the script */
 516         if (SQ_SUCCEEDED(LoadFile(vm, script, SQTrue))) {
 517                 sq_push(vm, -2);
 518                 if (SQ_SUCCEEDED(sq_call(vm, 1, SQFalse, SQTrue, 100000))) {
 519                         sq_pop(vm, 1);
 520                         /* After compiling the file we want to reset the amount of opcodes. */
 521                         vm->_ops_till_suspend = ops_left;
 522                         return true;
 523                 }
 524         }
 525
 526         vm->_ops_till_suspend = ops_left;
 527         DEBUG(misc, 0, "[squirrel] Failed to compile '%s'", script);
 528         return false;
 529 }
 530
 531 bool Squirrel::LoadScript(const char *script)
 532 {
 533         return LoadScript(this->vm, script);
 534 }
 535
 536 Squirrel::~Squirrel()
 537 {
 538         this->Uninitialize();
 539 }
 540
 541 void Squirrel::Uninitialize()
 542 {
 543         /* Clean up the stuff */
 544         sq_pop(this->vm, 1);
 545         sq_close(this->vm);
 546 }
 547
 548 void Squirrel::Reset()
 549 {
 550         this->Uninitialize();
 551         this->Initialize();
 552 }
 553
 554 void Squirrel::InsertResult(bool result)
 555 {
 556         sq_pushbool(this->vm, result);
 557         if (this->IsSuspended()) { // Called before resuming a suspended script?
 558                 vm->GetAt(vm->_stackbase + vm->_suspended_target) = vm->GetUp(-1);
 559                 vm->Pop();
 560         }
 561 }
 562
 563 void Squirrel::InsertResult(int result)
 564 {
 565         sq_pushinteger(this->vm, result);
 566         if (this->IsSuspended()) { // Called before resuming a suspended script?
 567                 vm->GetAt(vm->_stackbase + vm->_suspended_target) = vm->GetUp(-1);
 568                 vm->Pop();
 569         }
 570 }
 571
 572 /* static */ void Squirrel::DecreaseOps(HSQUIRRELVM vm, int ops)
 573 {
 574         vm->DecreaseOps(ops);
 575 }
 576
 577 bool Squirrel::IsSuspended()
 578 {
 579         return this->vm->_suspended != 0;
 580 }
 581
 582 bool Squirrel::HasScriptCrashed()
 583 {
 584         return this->crashed;
 585 }
 586
 587 void Squirrel::CrashOccurred()
 588 {
 589         this->crashed = true;
 590 }
 591
 592 bool Squirrel::CanSuspend()
 593 {
 594         return sq_can_suspend(this->vm);
 595 }
 596
 597 SQInteger Squirrel::GetOpsTillSuspend()
 598 {
 599         return this->vm->_ops_till_suspend;
 600 }