lua/include/lobject.h

   1 /*
   2 ** $Id: lobject.h,v 2.117.1.1 2017/04/19 17:39:34 roberto Exp $
   3 ** Type definitions for Lua objects
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #ifndef lobject_h
   9 #define lobject_h
  10
  11
  12 #include <stdarg.h>
  13
  14
  15 #include "llimits.h"
  16 #include "lua.h"
  17
  18
  19 /*
  20 ** Extra tags for non-values
  21 */
  22 #define LUA_TPROTO      LUA_NUMTAGS             /* function prototypes */
  23 #define LUA_TDEADKEY    (LUA_NUMTAGS+1)         /* removed keys in tables */
  24
  25 /*
  26 ** number of all possible tags (including LUA_TNONE but excluding DEADKEY)
  27 */
  28 #define LUA_TOTALTAGS   (LUA_TPROTO + 2)
  29
  30
  31 /*
  32 ** tags for Tagged Values have the following use of bits:
  33 ** bits 0-3: actual tag (a LUA_T* value)
  34 ** bits 4-5: variant bits
  35 ** bit 6: whether value is collectable
  36 */
  37
  38
  39 /*
  40 ** LUA_TFUNCTION variants:
  41 ** 0 - Lua function
  42 ** 1 - light C function
  43 ** 2 - regular C function (closure)
  44 */
  45
  46 /* Variant tags for functions */
  47 #define LUA_TLCL        (LUA_TFUNCTION | (0 << 4))  /* Lua closure */
  48 #define LUA_TLCF        (LUA_TFUNCTION | (1 << 4))  /* light C function */
  49 #define LUA_TCCL        (LUA_TFUNCTION | (2 << 4))  /* C closure */
  50
  51
  52 /* Variant tags for strings */
  53 #define LUA_TSHRSTR     (LUA_TSTRING | (0 << 4))  /* short strings */
  54 #define LUA_TLNGSTR     (LUA_TSTRING | (1 << 4))  /* long strings */
  55
  56
  57 /* Variant tags for numbers */
  58 #define LUA_TNUMFLT     (LUA_TNUMBER | (0 << 4))  /* float numbers */
  59 #define LUA_TNUMINT     (LUA_TNUMBER | (1 << 4))  /* integer numbers */
  60
  61
  62 /* Bit mark for collectable types */
  63 #define BIT_ISCOLLECTABLE       (1 << 6)
  64
  65 /* mark a tag as collectable */
  66 #define ctb(t)                  ((t) | BIT_ISCOLLECTABLE)
  67
  68
  69 /*
  70 ** Common type for all collectable objects
  71 */
  72 typedef struct GCObject GCObject;
  73
  74
  75 /*
  76 ** Common Header for all collectable objects (in macro form, to be
  77 ** included in other objects)
  78 */
  79 #define CommonHeader    GCObject *next; lu_byte tt; lu_byte marked
  80
  81
  82 /*
  83 ** Common type has only the common header
  84 */
  85 struct GCObject {
  86   CommonHeader;
  87 };
  88
  89
  90
  91
  92 /*
  93 ** Tagged Values. This is the basic representation of values in Lua,
  94 ** an actual value plus a tag with its type.
  95 */
  96
  97 /*
  98 ** Union of all Lua values
  99 */
 100 typedef union Value {
 101   GCObject *gc;    /* collectable objects */
 102   void *p;         /* light userdata */
 103   int b;           /* booleans */
 104   lua_CFunction f; /* light C functions */
 105   lua_Integer i;   /* integer numbers */
 106   lua_Number n;    /* float numbers */
 107 } Value;
 108
 109
 110 #define TValuefields    Value value_; int tt_
 111
 112
 113 typedef struct lua_TValue {
 114   TValuefields;
 115 } TValue;
 116
 117
 118
 119 /* macro defining a nil value */
 120 #define NILCONSTANT     {NULL}, LUA_TNIL
 121
 122
 123 #define val_(o)         ((o)->value_)
 124
 125
 126 /* raw type tag of a TValue */
 127 #define rttype(o)       ((o)->tt_)
 128
 129 /* tag with no variants (bits 0-3) */
 130 #define novariant(x)    ((x) & 0x0F)
 131
 132 /* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
 133 #define ttype(o)        (rttype(o) & 0x3F)
 134
 135 /* type tag of a TValue with no variants (bits 0-3) */
 136 #define ttnov(o)        (novariant(rttype(o)))
 137
 138
 139 /* Macros to test type */
 140 #define checktag(o,t)           (rttype(o) == (t))
 141 #define checktype(o,t)          (ttnov(o) == (t))
 142 #define ttisnumber(o)           checktype((o), LUA_TNUMBER)
 143 #define ttisfloat(o)            checktag((o), LUA_TNUMFLT)
 144 #define ttisinteger(o)          checktag((o), LUA_TNUMINT)
 145 #define ttisnil(o)              checktag((o), LUA_TNIL)
 146 #define ttisboolean(o)          checktag((o), LUA_TBOOLEAN)
 147 #define ttislightuserdata(o)    checktag((o), LUA_TLIGHTUSERDATA)
 148 #define ttisstring(o)           checktype((o), LUA_TSTRING)
 149 #define ttisshrstring(o)        checktag((o), ctb(LUA_TSHRSTR))
 150 #define ttislngstring(o)        checktag((o), ctb(LUA_TLNGSTR))
 151 #define ttistable(o)            checktag((o), ctb(LUA_TTABLE))
 152 #define ttisfunction(o)         checktype(o, LUA_TFUNCTION)
 153 #define ttisclosure(o)          ((rttype(o) & 0x1F) == LUA_TFUNCTION)
 154 #define ttisCclosure(o)         checktag((o), ctb(LUA_TCCL))
 155 #define ttisLclosure(o)         checktag((o), ctb(LUA_TLCL))
 156 #define ttislcf(o)              checktag((o), LUA_TLCF)
 157 #define ttisfulluserdata(o)     checktag((o), ctb(LUA_TUSERDATA))
 158 #define ttisthread(o)           checktag((o), ctb(LUA_TTHREAD))
 159 #define ttisdeadkey(o)          checktag((o), LUA_TDEADKEY)
 160
 161
 162 /* Macros to access values */
 163 #define ivalue(o)       check_exp(ttisinteger(o), val_(o).i)
 164 #define fltvalue(o)     check_exp(ttisfloat(o), val_(o).n)
 165 #define nvalue(o)       check_exp(ttisnumber(o), \
 166         (ttisinteger(o) ? cast_num(ivalue(o)) : fltvalue(o)))
 167 #define gcvalue(o)      check_exp(iscollectable(o), val_(o).gc)
 168 #define pvalue(o)       check_exp(ttislightuserdata(o), val_(o).p)
 169 #define tsvalue(o)      check_exp(ttisstring(o), gco2ts(val_(o).gc))
 170 #define uvalue(o)       check_exp(ttisfulluserdata(o), gco2u(val_(o).gc))
 171 #define clvalue(o)      check_exp(ttisclosure(o), gco2cl(val_(o).gc))
 172 #define clLvalue(o)     check_exp(ttisLclosure(o), gco2lcl(val_(o).gc))
 173 #define clCvalue(o)     check_exp(ttisCclosure(o), gco2ccl(val_(o).gc))
 174 #define fvalue(o)       check_exp(ttislcf(o), val_(o).f)
 175 #define hvalue(o)       check_exp(ttistable(o), gco2t(val_(o).gc))
 176 #define bvalue(o)       check_exp(ttisboolean(o), val_(o).b)
 177 #define thvalue(o)      check_exp(ttisthread(o), gco2th(val_(o).gc))
 178 /* a dead value may get the 'gc' field, but cannot access its contents */
 179 #define deadvalue(o)    check_exp(ttisdeadkey(o), cast(void *, val_(o).gc))
 180
 181 #define l_isfalse(o)    (ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))
 182
 183
 184 #define iscollectable(o)        (rttype(o) & BIT_ISCOLLECTABLE)
 185
 186
 187 /* Macros for internal tests */
 188 #define righttt(obj)            (ttype(obj) == gcvalue(obj)->tt)
 189
 190 #define checkliveness(L,obj) \
 191         lua_longassert(!iscollectable(obj) || \
 192                 (righttt(obj) && (L == NULL || !isdead(G(L),gcvalue(obj)))))
 193
 194
 195 /* Macros to set values */
 196 #define settt_(o,t)     ((o)->tt_=(t))
 197
 198 #define setfltvalue(obj,x) \
 199   { TValue *io=(obj); val_(io).n=(x); settt_(io, LUA_TNUMFLT); }
 200
 201 #define chgfltvalue(obj,x) \
 202   { TValue *io=(obj); lua_assert(ttisfloat(io)); val_(io).n=(x); }
 203
 204 #define setivalue(obj,x) \
 205   { TValue *io=(obj); val_(io).i=(x); settt_(io, LUA_TNUMINT); }
 206
 207 #define chgivalue(obj,x) \
 208   { TValue *io=(obj); lua_assert(ttisinteger(io)); val_(io).i=(x); }
 209
 210 #define setnilvalue(obj) settt_(obj, LUA_TNIL)
 211
 212 #define setfvalue(obj,x) \
 213   { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_TLCF); }
 214
 215 #define setpvalue(obj,x) \
 216   { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_TLIGHTUSERDATA); }
 217
 218 #define setbvalue(obj,x) \
 219   { TValue *io=(obj); val_(io).b=(x); settt_(io, LUA_TBOOLEAN); }
 220
 221 #define setgcovalue(L,obj,x) \
 222   { TValue *io = (obj); GCObject *i_g=(x); \
 223     val_(io).gc = i_g; settt_(io, ctb(i_g->tt)); }
 224
 225 #define setsvalue(L,obj,x) \
 226   { TValue *io = (obj); TString *x_ = (x); \
 227     val_(io).gc = obj2gco(x_); settt_(io, ctb(x_->tt)); \
 228     checkliveness(L,io); }
 229
 230 #define setuvalue(L,obj,x) \
 231   { TValue *io = (obj); Udata *x_ = (x); \
 232     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TUSERDATA)); \
 233     checkliveness(L,io); }
 234
 235 #define setthvalue(L,obj,x) \
 236   { TValue *io = (obj); lua_State *x_ = (x); \
 237     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTHREAD)); \
 238     checkliveness(L,io); }
 239
 240 #define setclLvalue(L,obj,x) \
 241   { TValue *io = (obj); LClosure *x_ = (x); \
 242     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TLCL)); \
 243     checkliveness(L,io); }
 244
 245 #define setclCvalue(L,obj,x) \
 246   { TValue *io = (obj); CClosure *x_ = (x); \
 247     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TCCL)); \
 248     checkliveness(L,io); }
 249
 250 #define sethvalue(L,obj,x) \
 251   { TValue *io = (obj); Table *x_ = (x); \
 252     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTABLE)); \
 253     checkliveness(L,io); }
 254
 255 #define setdeadvalue(obj)       settt_(obj, LUA_TDEADKEY)
 256
 257
 258
 259 #define setobj(L,obj1,obj2) \
 260         { TValue *io1=(obj1); *io1 = *(obj2); \
 261           (void)L; checkliveness(L,io1); }
 262
 263
 264 /*
 265 ** different types of assignments, according to destination
 266 */
 267
 268 /* from stack to (same) stack */
 269 #define setobjs2s       setobj
 270 /* to stack (not from same stack) */
 271 #define setobj2s        setobj
 272 #define setsvalue2s     setsvalue
 273 #define sethvalue2s     sethvalue
 274 #define setptvalue2s    setptvalue
 275 /* from table to same table */
 276 #define setobjt2t       setobj
 277 /* to new object */
 278 #define setobj2n        setobj
 279 #define setsvalue2n     setsvalue
 280
 281 /* to table (define it as an expression to be used in macros) */
 282 #define setobj2t(L,o1,o2)  ((void)L, *(o1)=*(o2), checkliveness(L,(o1)))
 283
 284
 285
 286
 287 /*
 288 ** {======================================================
 289 ** types and prototypes
 290 ** =======================================================
 291 */
 292
 293
 294 typedef TValue *StkId;  /* index to stack elements */
 295
 296
 297
 298
 299 /*
 300 ** Header for string value; string bytes follow the end of this structure
 301 ** (aligned according to 'UTString'; see next).
 302 */
 303 typedef struct TString {
 304   CommonHeader;
 305 #if defined(__LUATOS_SMALL_RAM__) && defined(__LUATOS_SCRIPT_BASE__)
 306   struct
 307   {
 308         uint16_t extra:5;
 309         uint16_t shrlen:6;
 310         uint16_t static_flag:5;
 311   };
 312   unsigned int hash;
 313   union {
 314         struct
 315         {
 316           uint32_t lnglen:17;/* length for long strings */
 317           uint32_t static_offset:15;
 318         };
 319     struct TString *hnext;  /* linked list for hash table */
 320
 321   } u;
 322 #else
 323   lu_byte extra;  /* reserved words for short strings; "has hash" for longs */
 324   lu_byte shrlen;  /* length for short strings */
 325   unsigned int hash;
 326   union {
 327     size_t lnglen;  /* length for long strings */
 328     struct TString *hnext;  /* linked list for hash table */
 329   } u;
 330 #endif
 331 } TString;
 332
 333
 334 /*
 335 ** Ensures that address after this type is always fully aligned.
 336 */
 337 typedef union UTString {
 338   L_Umaxalign dummy;  /* ensures maximum alignment for strings */
 339   TString tsv;
 340 } UTString;
 341
 342
 343 /*
 344 ** Get the actual string (array of bytes) from a 'TString'.
 345 ** (Access to 'extra' ensures that value is really a 'TString'.)
 346 */
 347 #if defined(__LUATOS_SMALL_RAM__) && defined(__LUATOS_SCRIPT_BASE__)
 348 char *getstr(TString *ts);
 349 #else
 350 #define getstr(ts)  \
 351   check_exp(sizeof((ts)->extra), cast(char *, (ts)) + sizeof(UTString))
 352 #endif
 353
 354 /* get the actual string (array of bytes) from a Lua value */
 355 #define svalue(o)       getstr(tsvalue(o))
 356
 357 /* get string length from 'TString *s' */
 358 #define tsslen(s)       ((s)->tt == LUA_TSHRSTR ? (s)->shrlen : (s)->u.lnglen)
 359
 360 /* get string length from 'TValue *o' */
 361 #define vslen(o)        tsslen(tsvalue(o))
 362
 363
 364 /*
 365 ** Header for userdata; memory area follows the end of this structure
 366 ** (aligned according to 'UUdata'; see next).
 367 */
 368 typedef struct Udata {
 369   CommonHeader;
 370   lu_byte ttuv_;  /* user value's tag */
 371   struct Table *metatable;
 372   size_t len;  /* number of bytes */
 373   union Value user_;  /* user value */
 374 } Udata;
 375
 376
 377 /*
 378 ** Ensures that address after this type is always fully aligned.
 379 */
 380 typedef union UUdata {
 381   L_Umaxalign dummy;  /* ensures maximum alignment for 'local' udata */
 382   Udata uv;
 383 } UUdata;
 384
 385
 386 /*
 387 **  Get the address of memory block inside 'Udata'.
 388 ** (Access to 'ttuv_' ensures that value is really a 'Udata'.)
 389 */
 390 #define getudatamem(u)  \
 391   check_exp(sizeof((u)->ttuv_), (cast(char*, (u)) + sizeof(UUdata)))
 392
 393 #define setuservalue(L,u,o) \
 394         { const TValue *io=(o); Udata *iu = (u); \
 395           iu->user_ = io->value_; iu->ttuv_ = rttype(io); \
 396           checkliveness(L,io); }
 397
 398
 399 #define getuservalue(L,u,o) \
 400         { TValue *io=(o); const Udata *iu = (u); \
 401           io->value_ = iu->user_; settt_(io, iu->ttuv_); \
 402           checkliveness(L,io); }
 403
 404
 405 /*
 406 ** Description of an upvalue for function prototypes
 407 */
 408 typedef struct Upvaldesc {
 409   TString *name;  /* upvalue name (for debug information) */
 410   lu_byte instack;  /* whether it is in stack (register) */
 411   lu_byte idx;  /* index of upvalue (in stack or in outer function's list) */
 412 } Upvaldesc;
 413
 414
 415 /*
 416 ** Description of a local variable for function prototypes
 417 ** (used for debug information)
 418 */
 419 typedef struct LocVar {
 420   TString *varname;
 421 #ifdef __LUATOS_SMALL_RAM__
 422   uint16_t startpc;
 423   uint16_t endpc;
 424 #else
 425   int startpc;  /* first point where variable is active */
 426   int endpc;    /* first point where variable is dead */
 427 #endif
 428 } LocVar;
 429
 430
 431 /*
 432 ** Function Prototypes
 433 */
 434 typedef struct Proto {
 435   CommonHeader;
 436   lu_byte numparams;  /* number of fixed parameters */
 437   lu_byte is_vararg;
 438   lu_byte maxstacksize;  /* number of registers needed by this function */
 439 #ifdef __LUATOS_SMALL_RAM__
 440   uint16_t sizeupvalues;  /* size of 'upvalues' */
 441   uint16_t sizek;  /* size of 'k' */
 442   uint16_t sizecode;
 443   uint16_t sizelineinfo;
 444   uint16_t sizep;  /* size of 'p' */
 445   uint16_t sizelocvars;
 446   uint16_t linedefined;
 447   uint16_t lastlinedefined;
 448 #else
 449   int sizeupvalues;  /* size of 'upvalues' */
 450   int sizek;  /* size of 'k' */
 451   int sizecode;
 452   int sizelineinfo;
 453   int sizep;  /* size of 'p' */
 454   int sizelocvars;
 455   int linedefined;  /* debug information  */
 456   int lastlinedefined;  /* debug information  */
 457 #endif
 458   TValue *k;  /* constants used by the function */
 459   Instruction *code;  /* opcodes */
 460   struct Proto **p;  /* functions defined inside the function */
 461   int *lineinfo;  /* map from opcodes to source lines (debug information) */
 462   LocVar *locvars;  /* information about local variables (debug information) */
 463   Upvaldesc *upvalues;  /* upvalue information */
 464   struct LClosure *cache;  /* last-created closure with this prototype */
 465   TString  *source;  /* used for debug information */
 466   GCObject *gclist;
 467 } Proto;
 468
 469
 470
 471 /*
 472 ** Lua Upvalues
 473 */
 474 typedef struct UpVal UpVal;
 475
 476
 477 /*
 478 ** Closures
 479 */
 480
 481 #define ClosureHeader \
 482         CommonHeader; lu_byte nupvalues; GCObject *gclist
 483
 484 typedef struct CClosure {
 485   ClosureHeader;
 486   lua_CFunction f;
 487   TValue upvalue[1];  /* list of upvalues */
 488 } CClosure;
 489
 490
 491 typedef struct LClosure {
 492   ClosureHeader;
 493   struct Proto *p;
 494   UpVal *upvals[1];  /* list of upvalues */
 495 } LClosure;
 496
 497
 498 typedef union Closure {
 499   CClosure c;
 500   LClosure l;
 501 } Closure;
 502
 503
 504 #define isLfunction(o)  ttisLclosure(o)
 505
 506 #define getproto(o)     (clLvalue(o)->p)
 507
 508
 509 /*
 510 ** Tables
 511 */
 512
 513 typedef union TKey {
 514   struct {
 515     TValuefields;
 516     int next;  /* for chaining (offset for next node) */
 517   } nk;
 518   TValue tvk;
 519 } TKey;
 520
 521
 522 /* copy a value into a key without messing up field 'next' */
 523 #define setnodekey(L,key,obj) \
 524         { TKey *k_=(key); const TValue *io_=(obj); \
 525           k_->nk.value_ = io_->value_; k_->nk.tt_ = io_->tt_; \
 526           (void)L; checkliveness(L,io_); }
 527
 528
 529 typedef struct Node {
 530   TValue i_val;
 531   TKey i_key;
 532 } Node;
 533
 534
 535 typedef struct Table {
 536   CommonHeader;
 537   lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
 538   lu_byte lsizenode;  /* log2 of size of 'node' array */
 539   unsigned int sizearray;  /* size of 'array' array */
 540   TValue *array;  /* array part */
 541   Node *node;
 542   Node *lastfree;  /* any free position is before this position */
 543   struct Table *metatable;
 544   GCObject *gclist;
 545 } Table;
 546
 547
 548
 549 /*
 550 ** 'module' operation for hashing (size is always a power of 2)
 551 */
 552 #define lmod(s,size) \
 553         (check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1)))))
 554
 555
 556 #define twoto(x)        (1<<(x))
 557 #define sizenode(t)     (twoto((t)->lsizenode))
 558
 559
 560 /*
 561 ** (address of) a fixed nil value
 562 */
 563 #define luaO_nilobject          (&luaO_nilobject_)
 564
 565
 566 LUAI_DDEC const TValue luaO_nilobject_;
 567
 568 /* size of buffer for 'luaO_utf8esc' function */
 569 #define UTF8BUFFSZ      8
 570
 571 LUAI_FUNC int luaO_int2fb (unsigned int x);
 572 LUAI_FUNC int luaO_fb2int (int x);
 573 LUAI_FUNC int luaO_utf8esc (char *buff, unsigned long x);
 574 LUAI_FUNC int luaO_ceillog2 (unsigned int x);
 575 LUAI_FUNC void luaO_arith (lua_State *L, int op, const TValue *p1,
 576                            const TValue *p2, TValue *res);
 577 LUAI_FUNC size_t luaO_str2num (const char *s, TValue *o);
 578 LUAI_FUNC int luaO_hexavalue (int c);
 579 LUAI_FUNC void luaO_tostring (lua_State *L, StkId obj);
 580 LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
 581                                                        va_list argp);
 582 LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
 583 LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);
 584
 585
 586 #endif
 587