lua/src/lapi.c

   1 /*
   2 ** $Id: lapi.c,v 2.159 2011/11/30 12:32:05 roberto Exp $
   3 ** Lua API
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <stdarg.h>
   9 #include <string.h>
  10
  11 #define lapi_c
  12 #define LUA_CORE
  13
  14 #include "lua.h"
  15
  16 #include "lapi.h"
  17 #include "ldebug.h"
  18 #include "ldo.h"
  19 #include "lfunc.h"
  20 #include "lgc.h"
  21 #include "lmem.h"
  22 #include "lobject.h"
  23 #include "lstate.h"
  24 #include "lstring.h"
  25 #include "ltable.h"
  26 #include "ltm.h"
  27 #include "lundump.h"
  28 #include "lvm.h"
  29
  30
  31
  32 const char lua_ident[] =
  33   "$LuaVersion: " LUA_COPYRIGHT " $"
  34   "$LuaAuthors: " LUA_AUTHORS " $";
  35
  36
  37 /* value at a non-valid index */
  38 #define NONVALIDVALUE           cast(TValue *, luaO_nilobject)
  39
  40 /* corresponding test */
  41 #define isvalid(o)      ((o) != luaO_nilobject)
  42
  43 #define api_checkvalidindex(L, i)  api_check(L, isvalid(i), "invalid index")
  44
  45
  46 static TValue *index2addr (lua_State *L, int idx) {
  47   CallInfo *ci = L->ci;
  48   if (idx > 0) {
  49     TValue *o = ci->func + idx;
  50     api_check(L, idx <= ci->top - (ci->func + 1), "unacceptable index");
  51     if (o >= L->top) return NONVALIDVALUE;
  52     else return o;
  53   }
  54   else if (idx > LUA_REGISTRYINDEX) {
  55     api_check(L, idx != 0 && -idx <= L->top - (ci->func + 1), "invalid index");
  56     return L->top + idx;
  57   }
  58   else if (idx == LUA_REGISTRYINDEX)
  59     return &G(L)->l_registry;
  60   else {  /* upvalues */
  61     idx = LUA_REGISTRYINDEX - idx;
  62     api_check(L, idx <= MAXUPVAL + 1, "upvalue index too large");
  63     if (ttislcf(ci->func))  /* light C function? */
  64       return NONVALIDVALUE;  /* it has no upvalues */
  65     else {
  66       CClosure *func = clCvalue(ci->func);
  67       return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : NONVALIDVALUE;
  68     }
  69   }
  70 }
  71
  72
  73 /*
  74 ** to be called by 'lua_checkstack' in protected mode, to grow stack
  75 ** capturing memory errors
  76 */
  77 static void growstack (lua_State *L, void *ud) {
  78   int size = *(int *)ud;
  79   luaD_growstack(L, size);
  80 }
  81
  82
  83 LUA_API int lua_checkstack (lua_State *L, int size) {
  84   int res;
  85   CallInfo *ci = L->ci;
  86   lua_lock(L);
  87   if (L->stack_last - L->top > size)  /* stack large enough? */
  88     res = 1;  /* yes; check is OK */
  89   else {  /* no; need to grow stack */
  90     int inuse = cast_int(L->top - L->stack) + EXTRA_STACK;
  91     if (inuse > LUAI_MAXSTACK - size)  /* can grow without overflow? */
  92       res = 0;  /* no */
  93     else  /* try to grow stack */
  94       res = (luaD_rawrunprotected(L, &growstack, &size) == LUA_OK);
  95   }
  96   if (res && ci->top < L->top + size)
  97     ci->top = L->top + size;  /* adjust frame top */
  98   lua_unlock(L);
  99   return res;
 100 }
 101
 102
 103 LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
 104   int i;
 105   if (from == to) return;
 106   lua_lock(to);
 107   api_checknelems(from, n);
 108   api_check(from, G(from) == G(to), "moving among independent states");
 109   api_check(from, to->ci->top - to->top >= n, "not enough elements to move");
 110   from->top -= n;
 111   for (i = 0; i < n; i++) {
 112     setobj2s(to, to->top++, from->top + i);
 113   }
 114   lua_unlock(to);
 115 }
 116
 117
 118 LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
 119   lua_CFunction old;
 120   lua_lock(L);
 121   old = G(L)->panic;
 122   G(L)->panic = panicf;
 123   lua_unlock(L);
 124   return old;
 125 }
 126
 127
 128 LUA_API const lua_Number *lua_version (lua_State *L) {
 129   static const lua_Number version = LUA_VERSION_NUM;
 130   if (L == NULL) return &version;
 131   else return G(L)->version;
 132 }
 133
 134
 135
 136 /*
 137 ** basic stack manipulation
 138 */
 139
 140
 141 /*
 142 ** convert an acceptable stack index into an absolute index
 143 */
 144 LUA_API int lua_absindex (lua_State *L, int idx) {
 145   return (idx > 0 || idx <= LUA_REGISTRYINDEX)
 146          ? idx
 147          : cast_int(L->top - L->ci->func + idx);
 148 }
 149
 150
 151 LUA_API int lua_gettop (lua_State *L) {
 152   return cast_int(L->top - (L->ci->func + 1));
 153 }
 154
 155
 156 LUA_API void lua_settop (lua_State *L, int idx) {
 157   StkId func = L->ci->func;
 158   lua_lock(L);
 159   if (idx >= 0) {
 160     api_check(L, idx <= L->stack_last - (func + 1), "new top too large");
 161     while (L->top < (func + 1) + idx)
 162       setnilvalue(L->top++);
 163     L->top = (func + 1) + idx;
 164   }
 165   else {
 166     api_check(L, -(idx+1) <= (L->top - (func + 1)), "invalid new top");
 167     L->top += idx+1;  /* `subtract' index (index is negative) */
 168   }
 169   lua_unlock(L);
 170 }
 171
 172
 173 LUA_API void lua_remove (lua_State *L, int idx) {
 174   StkId p;
 175   lua_lock(L);
 176   p = index2addr(L, idx);
 177   api_checkvalidindex(L, p);
 178   while (++p < L->top) setobjs2s(L, p-1, p);
 179   L->top--;
 180   lua_unlock(L);
 181 }
 182
 183
 184 LUA_API void lua_insert (lua_State *L, int idx) {
 185   StkId p;
 186   StkId q;
 187   lua_lock(L);
 188   p = index2addr(L, idx);
 189   api_checkvalidindex(L, p);
 190   for (q = L->top; q>p; q--) setobjs2s(L, q, q-1);
 191   setobjs2s(L, p, L->top);
 192   lua_unlock(L);
 193 }
 194
 195
 196 static void moveto (lua_State *L, TValue *fr, int idx) {
 197   TValue *to = index2addr(L, idx);
 198   api_checkvalidindex(L, to);
 199   setobj(L, to, fr);
 200   if (idx < LUA_REGISTRYINDEX)  /* function upvalue? */
 201     luaC_barrier(L, clCvalue(L->ci->func), fr);
 202   /* LUA_REGISTRYINDEX does not need gc barrier
 203      (collector revisits it before finishing collection) */
 204 }
 205
 206
 207 LUA_API void lua_replace (lua_State *L, int idx) {
 208   lua_lock(L);
 209   api_checknelems(L, 1);
 210   moveto(L, L->top - 1, idx);
 211   L->top--;
 212   lua_unlock(L);
 213 }
 214
 215
 216 LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) {
 217   TValue *fr;
 218   lua_lock(L);
 219   fr = index2addr(L, fromidx);
 220   api_checkvalidindex(L, fr);
 221   moveto(L, fr, toidx);
 222   lua_unlock(L);
 223 }
 224
 225
 226 LUA_API void lua_pushvalue (lua_State *L, int idx) {
 227   lua_lock(L);
 228   setobj2s(L, L->top, index2addr(L, idx));
 229   api_incr_top(L);
 230   lua_unlock(L);
 231 }
 232
 233
 234
 235 /*
 236 ** access functions (stack -> C)
 237 */
 238
 239
 240 LUA_API int lua_type (lua_State *L, int idx) {
 241   StkId o = index2addr(L, idx);
 242   return (isvalid(o) ? ttypenv(o) : LUA_TNONE);
 243 }
 244
 245
 246 LUA_API const char *lua_typename (lua_State *L, int t) {
 247   UNUSED(L);
 248   return ttypename(t);
 249 }
 250
 251
 252 LUA_API int lua_iscfunction (lua_State *L, int idx) {
 253   StkId o = index2addr(L, idx);
 254   return (ttislcf(o) || (ttisCclosure(o)));
 255 }
 256
 257
 258 LUA_API int lua_isnumber (lua_State *L, int idx) {
 259   TValue n;
 260   const TValue *o = index2addr(L, idx);
 261   return tonumber(o, &n);
 262 }
 263
 264
 265 LUA_API int lua_isstring (lua_State *L, int idx) {
 266   int t = lua_type(L, idx);
 267   return (t == LUA_TSTRING || t == LUA_TNUMBER);
 268 }
 269
 270
 271 LUA_API int lua_isuserdata (lua_State *L, int idx) {
 272   const TValue *o = index2addr(L, idx);
 273   return (ttisuserdata(o) || ttislightuserdata(o));
 274 }
 275
 276
 277 LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
 278   StkId o1 = index2addr(L, index1);
 279   StkId o2 = index2addr(L, index2);
 280   return (isvalid(o1) && isvalid(o2)) ? luaV_rawequalobj(o1, o2) : 0;
 281 }
 282
 283
 284 LUA_API void  lua_arith (lua_State *L, int op) {
 285   StkId o1;  /* 1st operand */
 286   StkId o2;  /* 2nd operand */
 287   lua_lock(L);
 288   if (op != LUA_OPUNM) /* all other operations expect two operands */
 289     api_checknelems(L, 2);
 290   else {  /* for unary minus, add fake 2nd operand */
 291     api_checknelems(L, 1);
 292     setobjs2s(L, L->top, L->top - 1);
 293     L->top++;
 294   }
 295   o1 = L->top - 2;
 296   o2 = L->top - 1;
 297   if (ttisnumber(o1) && ttisnumber(o2)) {
 298     changenvalue(o1, luaO_arith(op, nvalue(o1), nvalue(o2)));
 299   }
 300   else
 301     luaV_arith(L, o1, o1, o2, cast(TMS, op - LUA_OPADD + TM_ADD));
 302   L->top--;
 303   lua_unlock(L);
 304 }
 305
 306
 307 LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
 308   StkId o1, o2;
 309   int i = 0;
 310   lua_lock(L);  /* may call tag method */
 311   o1 = index2addr(L, index1);
 312   o2 = index2addr(L, index2);
 313   if (isvalid(o1) && isvalid(o2)) {
 314     switch (op) {
 315       case LUA_OPEQ: i = equalobj(L, o1, o2); break;
 316       case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break;
 317       case LUA_OPLE: i = luaV_lessequal(L, o1, o2); break;
 318       default: api_check(L, 0, "invalid option");
 319     }
 320   }
 321   lua_unlock(L);
 322   return i;
 323 }
 324
 325
 326 LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *isnum) {
 327   TValue n;
 328   const TValue *o = index2addr(L, idx);
 329   if (tonumber(o, &n)) {
 330     if (isnum) *isnum = 1;
 331     return nvalue(o);
 332   }
 333   else {
 334     if (isnum) *isnum = 0;
 335     return 0;
 336   }
 337 }
 338
 339
 340 LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *isnum) {
 341   TValue n;
 342   const TValue *o = index2addr(L, idx);
 343   if (tonumber(o, &n)) {
 344     lua_Integer res;
 345     lua_Number num = nvalue(o);
 346     lua_number2integer(res, num);
 347     if (isnum) *isnum = 1;
 348     return res;
 349   }
 350   else {
 351     if (isnum) *isnum = 0;
 352     return 0;
 353   }
 354 }
 355
 356
 357 LUA_API lua_Unsigned lua_tounsignedx (lua_State *L, int idx, int *isnum) {
 358   TValue n;
 359   const TValue *o = index2addr(L, idx);
 360   if (tonumber(o, &n)) {
 361     lua_Unsigned res;
 362     lua_Number num = nvalue(o);
 363     lua_number2unsigned(res, num);
 364     if (isnum) *isnum = 1;
 365     return res;
 366   }
 367   else {
 368     if (isnum) *isnum = 0;
 369     return 0;
 370   }
 371 }
 372
 373
 374 LUA_API int lua_toboolean (lua_State *L, int idx) {
 375   const TValue *o = index2addr(L, idx);
 376   return !l_isfalse(o);
 377 }
 378
 379
 380 LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
 381   StkId o = index2addr(L, idx);
 382   if (!ttisstring(o)) {
 383     lua_lock(L);  /* `luaV_tostring' may create a new string */
 384     if (!luaV_tostring(L, o)) {  /* conversion failed? */
 385       if (len != NULL) *len = 0;
 386       lua_unlock(L);
 387       return NULL;
 388     }
 389     luaC_checkGC(L);
 390     o = index2addr(L, idx);  /* previous call may reallocate the stack */
 391     lua_unlock(L);
 392   }
 393   if (len != NULL) *len = tsvalue(o)->len;
 394   return svalue(o);
 395 }
 396
 397
 398 LUA_API size_t lua_rawlen (lua_State *L, int idx) {
 399   StkId o = index2addr(L, idx);
 400   switch (ttypenv(o)) {
 401     case LUA_TSTRING: return tsvalue(o)->len;
 402     case LUA_TUSERDATA: return uvalue(o)->len;
 403     case LUA_TTABLE: return luaH_getn(hvalue(o));
 404     default: return 0;
 405   }
 406 }
 407
 408
 409 LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
 410   StkId o = index2addr(L, idx);
 411   if (ttislcf(o)) return fvalue(o);
 412   else if (ttisCclosure(o))
 413     return clCvalue(o)->f;
 414   else return NULL;  /* not a C function */
 415 }
 416
 417
 418 LUA_API void *lua_touserdata (lua_State *L, int idx) {
 419   StkId o = index2addr(L, idx);
 420   switch (ttypenv(o)) {
 421     case LUA_TUSERDATA: return (rawuvalue(o) + 1);
 422     case LUA_TLIGHTUSERDATA: return pvalue(o);
 423     default: return NULL;
 424   }
 425 }
 426
 427
 428 LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
 429   StkId o = index2addr(L, idx);
 430   return (!ttisthread(o)) ? NULL : thvalue(o);
 431 }
 432
 433
 434 LUA_API const void *lua_topointer (lua_State *L, int idx) {
 435   StkId o = index2addr(L, idx);
 436   switch (ttype(o)) {
 437     case LUA_TTABLE: return hvalue(o);
 438     case LUA_TLCL: return clLvalue(o);
 439     case LUA_TCCL: return clCvalue(o);
 440     case LUA_TLCF: return cast(void *, cast(size_t, fvalue(o)));
 441     case LUA_TTHREAD: return thvalue(o);
 442     case LUA_TUSERDATA:
 443     case LUA_TLIGHTUSERDATA:
 444       return lua_touserdata(L, idx);
 445     default: return NULL;
 446   }
 447 }
 448
 449
 450
 451 /*
 452 ** push functions (C -> stack)
 453 */
 454
 455
 456 LUA_API void lua_pushnil (lua_State *L) {
 457   lua_lock(L);
 458   setnilvalue(L->top);
 459   api_incr_top(L);
 460   lua_unlock(L);
 461 }
 462
 463
 464 LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
 465   lua_lock(L);
 466   setnvalue(L->top, n);
 467   luai_checknum(L, L->top,
 468     luaG_runerror(L, "C API - attempt to push a signaling NaN"));
 469   api_incr_top(L);
 470   lua_unlock(L);
 471 }
 472
 473
 474 LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
 475   lua_lock(L);
 476   setnvalue(L->top, cast_num(n));
 477   api_incr_top(L);
 478   lua_unlock(L);
 479 }
 480
 481
 482 LUA_API void lua_pushunsigned (lua_State *L, lua_Unsigned u) {
 483   lua_Number n;
 484   lua_lock(L);
 485   n = lua_unsigned2number(u);
 486   setnvalue(L->top, n);
 487   api_incr_top(L);
 488   lua_unlock(L);
 489 }
 490
 491
 492 LUA_API const char *lua_pushlstring (lua_State *L, const char *s, size_t len) {
 493   TString *ts;
 494   lua_lock(L);
 495   luaC_checkGC(L);
 496   ts = luaS_newlstr(L, s, len);
 497   setsvalue2s(L, L->top, ts);
 498   api_incr_top(L);
 499   lua_unlock(L);
 500   return getstr(ts);
 501 }
 502
 503
 504 LUA_API const char *lua_pushstring (lua_State *L, const char *s) {
 505   if (s == NULL) {
 506     lua_pushnil(L);
 507     return NULL;
 508   }
 509   else {
 510     TString *ts;
 511     lua_lock(L);
 512     luaC_checkGC(L);
 513     ts = luaS_new(L, s);
 514     setsvalue2s(L, L->top, ts);
 515     api_incr_top(L);
 516     lua_unlock(L);
 517     return getstr(ts);
 518   }
 519 }
 520
 521
 522 LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
 523                                       va_list argp) {
 524   const char *ret;
 525   lua_lock(L);
 526   luaC_checkGC(L);
 527   ret = luaO_pushvfstring(L, fmt, argp);
 528   lua_unlock(L);
 529   return ret;
 530 }
 531
 532
 533 LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
 534   const char *ret;
 535   va_list argp;
 536   lua_lock(L);
 537   luaC_checkGC(L);
 538   va_start(argp, fmt);
 539   ret = luaO_pushvfstring(L, fmt, argp);
 540   va_end(argp);
 541   lua_unlock(L);
 542   return ret;
 543 }
 544
 545
 546 LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
 547   lua_lock(L);
 548   if (n == 0) {
 549     setfvalue(L->top, fn);
 550   }
 551   else {
 552     Closure *cl;
 553     api_checknelems(L, n);
 554     api_check(L, n <= MAXUPVAL, "upvalue index too large");
 555     luaC_checkGC(L);
 556     cl = luaF_newCclosure(L, n);
 557     cl->c.f = fn;
 558     L->top -= n;
 559     while (n--)
 560       setobj2n(L, &cl->c.upvalue[n], L->top + n);
 561     setclCvalue(L, L->top, cl);
 562   }
 563   api_incr_top(L);
 564   lua_unlock(L);
 565 }
 566
 567
 568 LUA_API void lua_pushboolean (lua_State *L, int b) {
 569   lua_lock(L);
 570   setbvalue(L->top, (b != 0));  /* ensure that true is 1 */
 571   api_incr_top(L);
 572   lua_unlock(L);
 573 }
 574
 575
 576 LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
 577   lua_lock(L);
 578   setpvalue(L->top, p);
 579   api_incr_top(L);
 580   lua_unlock(L);
 581 }
 582
 583
 584 LUA_API int lua_pushthread (lua_State *L) {
 585   lua_lock(L);
 586   setthvalue(L, L->top, L);
 587   api_incr_top(L);
 588   lua_unlock(L);
 589   return (G(L)->mainthread == L);
 590 }
 591
 592
 593
 594 /*
 595 ** get functions (Lua -> stack)
 596 */
 597
 598
 599 LUA_API void lua_getglobal (lua_State *L, const char *var) {
 600   Table *reg = hvalue(&G(L)->l_registry);
 601   const TValue *gt;  /* global table */
 602   lua_lock(L);
 603   gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
 604   setsvalue2s(L, L->top++, luaS_new(L, var));
 605   luaV_gettable(L, gt, L->top - 1, L->top - 1);
 606   lua_unlock(L);
 607 }
 608
 609
 610 LUA_API void lua_gettable (lua_State *L, int idx) {
 611   StkId t;
 612   lua_lock(L);
 613   t = index2addr(L, idx);
 614   api_checkvalidindex(L, t);
 615   luaV_gettable(L, t, L->top - 1, L->top - 1);
 616   lua_unlock(L);
 617 }
 618
 619
 620 LUA_API void lua_getfield (lua_State *L, int idx, const char *k) {
 621   StkId t;
 622   lua_lock(L);
 623   t = index2addr(L, idx);
 624   api_checkvalidindex(L, t);
 625   setsvalue2s(L, L->top, luaS_new(L, k));
 626   api_incr_top(L);
 627   luaV_gettable(L, t, L->top - 1, L->top - 1);
 628   lua_unlock(L);
 629 }
 630
 631
 632 LUA_API void lua_rawget (lua_State *L, int idx) {
 633   StkId t;
 634   lua_lock(L);
 635   t = index2addr(L, idx);
 636   api_check(L, ttistable(t), "table expected");
 637   setobj2s(L, L->top - 1, luaH_get(hvalue(t), L->top - 1));
 638   lua_unlock(L);
 639 }
 640
 641
 642 LUA_API void lua_rawgeti (lua_State *L, int idx, int n) {
 643   StkId t;
 644   lua_lock(L);
 645   t = index2addr(L, idx);
 646   api_check(L, ttistable(t), "table expected");
 647   setobj2s(L, L->top, luaH_getint(hvalue(t), n));
 648   api_incr_top(L);
 649   lua_unlock(L);
 650 }
 651
 652
 653 LUA_API void lua_rawgetp (lua_State *L, int idx, const void *p) {
 654   StkId t;
 655   TValue k;
 656   lua_lock(L);
 657   t = index2addr(L, idx);
 658   api_check(L, ttistable(t), "table expected");
 659   setpvalue(&k, cast(void *, p));
 660   setobj2s(L, L->top, luaH_get(hvalue(t), &k));
 661   api_incr_top(L);
 662   lua_unlock(L);
 663 }
 664
 665
 666 LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
 667   Table *t;
 668   lua_lock(L);
 669   luaC_checkGC(L);
 670   t = luaH_new(L);
 671   sethvalue(L, L->top, t);
 672   api_incr_top(L);
 673   if (narray > 0 || nrec > 0)
 674     luaH_resize(L, t, narray, nrec);
 675   lua_unlock(L);
 676 }
 677
 678
 679 LUA_API int lua_getmetatable (lua_State *L, int objindex) {
 680   const TValue *obj;
 681   Table *mt = NULL;
 682   int res;
 683   lua_lock(L);
 684   obj = index2addr(L, objindex);
 685   switch (ttypenv(obj)) {
 686     case LUA_TTABLE:
 687       mt = hvalue(obj)->metatable;
 688       break;
 689     case LUA_TUSERDATA:
 690       mt = uvalue(obj)->metatable;
 691       break;
 692     default:
 693       mt = G(L)->mt[ttypenv(obj)];
 694       break;
 695   }
 696   if (mt == NULL)
 697     res = 0;
 698   else {
 699     sethvalue(L, L->top, mt);
 700     api_incr_top(L);
 701     res = 1;
 702   }
 703   lua_unlock(L);
 704   return res;
 705 }
 706
 707
 708 LUA_API void lua_getuservalue (lua_State *L, int idx) {
 709   StkId o;
 710   lua_lock(L);
 711   o = index2addr(L, idx);
 712   api_checkvalidindex(L, o);
 713   api_check(L, ttisuserdata(o), "userdata expected");
 714   if (uvalue(o)->env) {
 715     sethvalue(L, L->top, uvalue(o)->env);
 716   } else
 717     setnilvalue(L->top);
 718   api_incr_top(L);
 719   lua_unlock(L);
 720 }
 721
 722
 723 /*
 724 ** set functions (stack -> Lua)
 725 */
 726
 727
 728 LUA_API void lua_setglobal (lua_State *L, const char *var) {
 729   Table *reg = hvalue(&G(L)->l_registry);
 730   const TValue *gt;  /* global table */
 731   lua_lock(L);
 732   api_checknelems(L, 1);
 733   gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
 734   setsvalue2s(L, L->top++, luaS_new(L, var));
 735   luaV_settable(L, gt, L->top - 1, L->top - 2);
 736   L->top -= 2;  /* pop value and key */
 737   lua_unlock(L);
 738 }
 739
 740
 741 LUA_API void lua_settable (lua_State *L, int idx) {
 742   StkId t;
 743   lua_lock(L);
 744   api_checknelems(L, 2);
 745   t = index2addr(L, idx);
 746   api_checkvalidindex(L, t);
 747   luaV_settable(L, t, L->top - 2, L->top - 1);
 748   L->top -= 2;  /* pop index and value */
 749   lua_unlock(L);
 750 }
 751
 752
 753 LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
 754   StkId t;
 755   lua_lock(L);
 756   api_checknelems(L, 1);
 757   t = index2addr(L, idx);
 758   api_checkvalidindex(L, t);
 759   setsvalue2s(L, L->top++, luaS_new(L, k));
 760   luaV_settable(L, t, L->top - 1, L->top - 2);
 761   L->top -= 2;  /* pop value and key */
 762   lua_unlock(L);
 763 }
 764
 765
 766 LUA_API void lua_rawset (lua_State *L, int idx) {
 767   StkId t;
 768   lua_lock(L);
 769   api_checknelems(L, 2);
 770   t = index2addr(L, idx);
 771   api_check(L, ttistable(t), "table expected");
 772   setobj2t(L, luaH_set(L, hvalue(t), L->top-2), L->top-1);
 773   invalidateTMcache(hvalue(t));
 774   luaC_barrierback(L, gcvalue(t), L->top-1);
 775   L->top -= 2;
 776   lua_unlock(L);
 777 }
 778
 779
 780 LUA_API void lua_rawseti (lua_State *L, int idx, int n) {
 781   StkId t;
 782   lua_lock(L);
 783   api_checknelems(L, 1);
 784   t = index2addr(L, idx);
 785   api_check(L, ttistable(t), "table expected");
 786   luaH_setint(L, hvalue(t), n, L->top - 1);
 787   luaC_barrierback(L, gcvalue(t), L->top-1);
 788   L->top--;
 789   lua_unlock(L);
 790 }
 791
 792
 793 LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {
 794   StkId t;
 795   TValue k;
 796   lua_lock(L);
 797   api_checknelems(L, 1);
 798   t = index2addr(L, idx);
 799   api_check(L, ttistable(t), "table expected");
 800   setpvalue(&k, cast(void *, p));
 801   setobj2t(L, luaH_set(L, hvalue(t), &k), L->top - 1);
 802   luaC_barrierback(L, gcvalue(t), L->top - 1);
 803   L->top--;
 804   lua_unlock(L);
 805 }
 806
 807
 808 LUA_API int lua_setmetatable (lua_State *L, int objindex) {
 809   TValue *obj;
 810   Table *mt;
 811   lua_lock(L);
 812   api_checknelems(L, 1);
 813   obj = index2addr(L, objindex);
 814   api_checkvalidindex(L, obj);
 815   if (ttisnil(L->top - 1))
 816     mt = NULL;
 817   else {
 818     api_check(L, ttistable(L->top - 1), "table expected");
 819     mt = hvalue(L->top - 1);
 820   }
 821   switch (ttypenv(obj)) {
 822     case LUA_TTABLE: {
 823       hvalue(obj)->metatable = mt;
 824       if (mt)
 825         luaC_objbarrierback(L, gcvalue(obj), mt);
 826         luaC_checkfinalizer(L, gcvalue(obj), mt);
 827       break;
 828     }
 829     case LUA_TUSERDATA: {
 830       uvalue(obj)->metatable = mt;
 831       if (mt) {
 832         luaC_objbarrier(L, rawuvalue(obj), mt);
 833         luaC_checkfinalizer(L, gcvalue(obj), mt);
 834       }
 835       break;
 836     }
 837     default: {
 838       G(L)->mt[ttypenv(obj)] = mt;
 839       break;
 840     }
 841   }
 842   L->top--;
 843   lua_unlock(L);
 844   return 1;
 845 }
 846
 847
 848 LUA_API void lua_setuservalue (lua_State *L, int idx) {
 849   StkId o;
 850   lua_lock(L);
 851   api_checknelems(L, 1);
 852   o = index2addr(L, idx);
 853   api_checkvalidindex(L, o);
 854   api_check(L, ttisuserdata(o), "userdata expected");
 855   if (ttisnil(L->top - 1))
 856     uvalue(o)->env = NULL;
 857   else {
 858     api_check(L, ttistable(L->top - 1), "table expected");
 859     uvalue(o)->env = hvalue(L->top - 1);
 860     luaC_objbarrier(L, gcvalue(o), hvalue(L->top - 1));
 861   }
 862   L->top--;
 863   lua_unlock(L);
 864 }
 865
 866
 867 /*
 868 ** `load' and `call' functions (run Lua code)
 869 */
 870
 871
 872 #define checkresults(L,na,nr) \
 873      api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)), \
 874         "results from function overflow current stack size")
 875
 876
 877 LUA_API int lua_getctx (lua_State *L, int *ctx) {
 878   if (L->ci->callstatus & CIST_YIELDED) {
 879     if (ctx) *ctx = L->ci->u.c.ctx;
 880     return L->ci->u.c.status;
 881   }
 882   else return LUA_OK;
 883 }
 884
 885
 886 LUA_API void lua_callk (lua_State *L, int nargs, int nresults, int ctx,
 887                         lua_CFunction k) {
 888   StkId func;
 889   lua_lock(L);
 890   api_check(L, k == NULL || !isLua(L->ci),
 891     "cannot use continuations inside hooks");
 892   api_checknelems(L, nargs+1);
 893   api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
 894   checkresults(L, nargs, nresults);
 895   func = L->top - (nargs+1);
 896   if (k != NULL && L->nny == 0) {  /* need to prepare continuation? */
 897     L->ci->u.c.k = k;  /* save continuation */
 898     L->ci->u.c.ctx = ctx;  /* save context */
 899     luaD_call(L, func, nresults, 1);  /* do the call */
 900   }
 901   else  /* no continuation or no yieldable */
 902     luaD_call(L, func, nresults, 0);  /* just do the call */
 903   adjustresults(L, nresults);
 904   lua_unlock(L);
 905 }
 906
 907
 908
 909 /*
 910 ** Execute a protected call.
 911 */
 912 struct CallS {  /* data to `f_call' */
 913   StkId func;
 914   int nresults;
 915 };
 916
 917
 918 static void f_call (lua_State *L, void *ud) {
 919   struct CallS *c = cast(struct CallS *, ud);
 920   luaD_call(L, c->func, c->nresults, 0);
 921 }
 922
 923
 924
 925 LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
 926                         int ctx, lua_CFunction k) {
 927   struct CallS c;
 928   int status;
 929   ptrdiff_t func;
 930   lua_lock(L);
 931   api_check(L, k == NULL || !isLua(L->ci),
 932     "cannot use continuations inside hooks");
 933   api_checknelems(L, nargs+1);
 934   api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
 935   checkresults(L, nargs, nresults);
 936   if (errfunc == 0)
 937     func = 0;
 938   else {
 939     StkId o = index2addr(L, errfunc);
 940     api_checkvalidindex(L, o);
 941     func = savestack(L, o);
 942   }
 943   c.func = L->top - (nargs+1);  /* function to be called */
 944   if (k == NULL || L->nny > 0) {  /* no continuation or no yieldable? */
 945     c.nresults = nresults;  /* do a 'conventional' protected call */
 946     status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
 947   }
 948   else {  /* prepare continuation (call is already protected by 'resume') */
 949     CallInfo *ci = L->ci;
 950     ci->u.c.k = k;  /* save continuation */
 951     ci->u.c.ctx = ctx;  /* save context */
 952     /* save information for error recovery */
 953     ci->u.c.extra = savestack(L, c.func);
 954     ci->u.c.old_allowhook = L->allowhook;
 955     ci->u.c.old_errfunc = L->errfunc;
 956     L->errfunc = func;
 957     /* mark that function may do error recovery */
 958     ci->callstatus |= CIST_YPCALL;
 959     luaD_call(L, c.func, nresults, 1);  /* do the call */
 960     ci->callstatus &= ~CIST_YPCALL;
 961     L->errfunc = ci->u.c.old_errfunc;
 962     status = LUA_OK;  /* if it is here, there were no errors */
 963   }
 964   adjustresults(L, nresults);
 965   lua_unlock(L);
 966   return status;
 967 }
 968
 969
 970 LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
 971                       const char *chunkname, const char *mode) {
 972   ZIO z;
 973   int status;
 974   lua_lock(L);
 975   if (!chunkname) chunkname = "?";
 976   luaZ_init(L, &z, reader, data);
 977   status = luaD_protectedparser(L, &z, chunkname, mode);
 978   if (status == LUA_OK) {  /* no errors? */
 979     LClosure *f = clLvalue(L->top - 1);  /* get newly created function */
 980     if (f->nupvalues == 1) {  /* does it have one upvalue? */
 981       /* get global table from registry */
 982       Table *reg = hvalue(&G(L)->l_registry);
 983       const TValue *gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
 984       /* set global table as 1st upvalue of 'f' (may be LUA_ENV) */
 985       setobj(L, f->upvals[0]->v, gt);
 986       luaC_barrier(L, f->upvals[0], gt);
 987     }
 988   }
 989   lua_unlock(L);
 990   return status;
 991 }
 992
 993
 994 LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data) {
 995   int status;
 996   TValue *o;
 997   lua_lock(L);
 998   api_checknelems(L, 1);
 999   o = L->top - 1;
1000   if (isLfunction(o))
1001     status = luaU_dump(L, getproto(o), writer, data, 0);
1002   else
1003     status = 1;
1004   lua_unlock(L);
1005   return status;
1006 }
1007
1008
1009 LUA_API int  lua_status (lua_State *L) {
1010   return L->status;
1011 }
1012
1013
1014 /*
1015 ** Garbage-collection function
1016 */
1017
1018 LUA_API int lua_gc (lua_State *L, int what, int data) {
1019   int res = 0;
1020   global_State *g;
1021   lua_lock(L);
1022   g = G(L);
1023   switch (what) {
1024     case LUA_GCSTOP: {
1025       g->gcrunning = 0;
1026       break;
1027     }
1028     case LUA_GCRESTART: {
1029       luaE_setdebt(g, 0);
1030       g->gcrunning = 1;
1031       break;
1032     }
1033     case LUA_GCCOLLECT: {
1034       luaC_fullgc(L, 0);
1035       break;
1036     }
1037     case LUA_GCCOUNT: {
1038       /* GC values are expressed in Kbytes: #bytes/2^10 */
1039       res = cast_int(gettotalbytes(g) >> 10);
1040       break;
1041     }
1042     case LUA_GCCOUNTB: {
1043       res = cast_int(gettotalbytes(g) & 0x3ff);
1044       break;
1045     }
1046     case LUA_GCSTEP: {
1047       if (g->gckind == KGC_GEN) {  /* generational mode? */
1048         res = (g->lastmajormem == 0);  /* 1 if will do major collection */
1049         luaC_forcestep(L);  /* do a single step */
1050       }
1051       else {
1052         while (data-- >= 0) {
1053           luaC_forcestep(L);
1054           if (g->gcstate == GCSpause) {  /* end of cycle? */
1055             res = 1;  /* signal it */
1056             break;
1057           }
1058         }
1059       }
1060       break;
1061     }
1062     case LUA_GCSETPAUSE: {
1063       res = g->gcpause;
1064       g->gcpause = data;
1065       break;
1066     }
1067     case LUA_GCSETMAJORINC: {
1068       res = g->gcmajorinc;
1069       g->gcmajorinc = data;
1070       break;
1071     }
1072     case LUA_GCSETSTEPMUL: {
1073       res = g->gcstepmul;
1074       g->gcstepmul = data;
1075       break;
1076     }
1077     case LUA_GCISRUNNING: {
1078       res = g->gcrunning;
1079       break;
1080     }
1081     case LUA_GCGEN: {  /* change collector to generational mode */
1082       luaC_changemode(L, KGC_GEN);
1083       break;
1084     }
1085     case LUA_GCINC: {  /* change collector to incremental mode */
1086       luaC_changemode(L, KGC_NORMAL);
1087       break;
1088     }
1089     default: res = -1;  /* invalid option */
1090   }
1091   lua_unlock(L);
1092   return res;
1093 }
1094
1095
1096
1097 /*
1098 ** miscellaneous functions
1099 */
1100
1101
1102 LUA_API int lua_error (lua_State *L) {
1103   lua_lock(L);
1104   api_checknelems(L, 1);
1105   luaG_errormsg(L);
1106   lua_unlock(L);
1107   return 0;  /* to avoid warnings */
1108 }
1109
1110
1111 LUA_API int lua_next (lua_State *L, int idx) {
1112   StkId t;
1113   int more;
1114   lua_lock(L);
1115   t = index2addr(L, idx);
1116   api_check(L, ttistable(t), "table expected");
1117   more = luaH_next(L, hvalue(t), L->top - 1);
1118   if (more) {
1119     api_incr_top(L);
1120   }
1121   else  /* no more elements */
1122     L->top -= 1;  /* remove key */
1123   lua_unlock(L);
1124   return more;
1125 }
1126
1127
1128 LUA_API void lua_concat (lua_State *L, int n) {
1129   lua_lock(L);
1130   api_checknelems(L, n);
1131   if (n >= 2) {
1132     luaC_checkGC(L);
1133     luaV_concat(L, n);
1134   }
1135   else if (n == 0) {  /* push empty string */
1136     setsvalue2s(L, L->top, luaS_newlstr(L, "", 0));
1137     api_incr_top(L);
1138   }
1139   /* else n == 1; nothing to do */
1140   lua_unlock(L);
1141 }
1142
1143
1144 LUA_API void lua_len (lua_State *L, int idx) {
1145   StkId t;
1146   lua_lock(L);
1147   t = index2addr(L, idx);
1148   luaV_objlen(L, L->top, t);
1149   api_incr_top(L);
1150   lua_unlock(L);
1151 }
1152
1153
1154 LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) {
1155   lua_Alloc f;
1156   lua_lock(L);
1157   if (ud) *ud = G(L)->ud;
1158   f = G(L)->frealloc;
1159   lua_unlock(L);
1160   return f;
1161 }
1162
1163
1164 LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) {
1165   lua_lock(L);
1166   G(L)->ud = ud;
1167   G(L)->frealloc = f;
1168   lua_unlock(L);
1169 }
1170
1171
1172 LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
1173   Udata *u;
1174   lua_lock(L);
1175   luaC_checkGC(L);
1176   u = luaS_newudata(L, size, NULL);
1177   setuvalue(L, L->top, u);
1178   api_incr_top(L);
1179   lua_unlock(L);
1180   return u + 1;
1181 }
1182
1183
1184
1185 static const char *aux_upvalue (StkId fi, int n, TValue **val,
1186                                 GCObject **owner) {
1187   switch (ttype(fi)) {
1188     case LUA_TCCL: {  /* C closure */
1189       CClosure *f = clCvalue(fi);
1190       if (!(1 <= n && n <= f->nupvalues)) return NULL;
1191       *val = &f->upvalue[n-1];
1192       if (owner) *owner = obj2gco(f);
1193       return "";
1194     }
1195     case LUA_TLCL: {  /* Lua closure */
1196       LClosure *f = clLvalue(fi);
1197       TString *name;
1198       Proto *p = f->p;
1199       if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
1200       *val = f->upvals[n-1]->v;
1201       if (owner) *owner = obj2gco(f->upvals[n - 1]);
1202       name = p->upvalues[n-1].name;
1203       return (name == NULL) ? "" : getstr(name);
1204     }
1205     default: return NULL;  /* not a closure */
1206   }
1207 }
1208
1209
1210 LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
1211   const char *name;
1212   TValue *val = NULL;  /* to avoid warnings */
1213   lua_lock(L);
1214   name = aux_upvalue(index2addr(L, funcindex), n, &val, NULL);
1215   if (name) {
1216     setobj2s(L, L->top, val);
1217     api_incr_top(L);
1218   }
1219   lua_unlock(L);
1220   return name;
1221 }
1222
1223
1224 LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
1225   const char *name;
1226   TValue *val = NULL;  /* to avoid warnings */
1227   GCObject *owner = NULL;  /* to avoid warnings */
1228   StkId fi;
1229   lua_lock(L);
1230   fi = index2addr(L, funcindex);
1231   api_checknelems(L, 1);
1232   name = aux_upvalue(fi, n, &val, &owner);
1233   if (name) {
1234     L->top--;
1235     setobj(L, val, L->top);
1236     luaC_barrier(L, owner, L->top);
1237   }
1238   lua_unlock(L);
1239   return name;
1240 }
1241
1242
1243 static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) {
1244   LClosure *f;
1245   StkId fi = index2addr(L, fidx);
1246   api_check(L, ttisLclosure(fi), "Lua function expected");
1247   f = clLvalue(fi);
1248   api_check(L, (1 <= n && n <= f->p->sizeupvalues), "invalid upvalue index");
1249   if (pf) *pf = f;
1250   return &f->upvals[n - 1];  /* get its upvalue pointer */
1251 }
1252
1253
1254 LUA_API void *lua_upvalueid (lua_State *L, int fidx, int n) {
1255   StkId fi = index2addr(L, fidx);
1256   switch (ttype(fi)) {
1257     case LUA_TLCL: {  /* lua closure */
1258       return *getupvalref(L, fidx, n, NULL);
1259     }
1260     case LUA_TCCL: {  /* C closure */
1261       CClosure *f = clCvalue(fi);
1262       api_check(L, 1 <= n && n <= f->nupvalues, "invalid upvalue index");
1263       return &f->upvalue[n - 1];
1264     }
1265     default: {
1266       api_check(L, 0, "closure expected");
1267       return NULL;
1268     }
1269   }
1270 }
1271
1272
1273 LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1,
1274                                             int fidx2, int n2) {
1275   LClosure *f1;
1276   UpVal **up1 = getupvalref(L, fidx1, n1, &f1);
1277   UpVal **up2 = getupvalref(L, fidx2, n2, NULL);
1278   *up1 = *up2;
1279   luaC_objbarrier(L, f1, *up2);
1280 }
1281