1/*
2** $Id: lobject.h,v 2.71 2012/09/11 18:21:44 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
23#define LUA_TUPVAL	(LUA_NUMTAGS+1)
24#define LUA_TDEADKEY	(LUA_NUMTAGS+2)
25
26/*
27** number of all possible tags (including LUA_TNONE but excluding DEADKEY)
28*/
29#define LUA_TOTALTAGS	(LUA_TUPVAL+2)
30
31
32/*
33** tags for Tagged Values have the following use of bits:
34** bits 0-3: actual tag (a LUA_T* value)
35** bits 4-5: variant bits
36** bit 6: whether value is collectable
37*/
38
39#define VARBITS		(3 << 4)
40
41
42/*
43** LUA_TFUNCTION variants:
44** 0 - Lua function
45** 1 - light C function
46** 2 - regular C function (closure)
47*/
48
49/* Variant tags for functions */
50#define LUA_TLCL	(LUA_TFUNCTION | (0 << 4))  /* Lua closure */
51#define LUA_TLCF	(LUA_TFUNCTION | (1 << 4))  /* light C function */
52#define LUA_TCCL	(LUA_TFUNCTION | (2 << 4))  /* C closure */
53
54
55/* Variant tags for strings */
56#define LUA_TSHRSTR	(LUA_TSTRING | (0 << 4))  /* short strings */
57#define LUA_TLNGSTR	(LUA_TSTRING | (1 << 4))  /* long strings */
58
59
60/* Bit mark for collectable types */
61#define BIT_ISCOLLECTABLE	(1 << 6)
62
63/* mark a tag as collectable */
64#define ctb(t)			((t) | BIT_ISCOLLECTABLE)
65
66
67/*
68** Union of all collectable objects
69*/
70typedef union GCObject GCObject;
71
72
73/*
74** Common Header for all collectable objects (in macro form, to be
75** included in other objects)
76*/
77#define CommonHeader	GCObject *next; lu_byte tt; lu_byte marked
78
79
80/*
81** Common header in struct form
82*/
83typedef struct GCheader {
84  CommonHeader;
85} GCheader;
86
87
88
89/*
90** Union of all Lua values
91*/
92typedef union Value Value;
93
94
95#define numfield	lua_Number n;    /* numbers */
96
97
98
99/*
100** Tagged Values. This is the basic representation of values in Lua,
101** an actual value plus a tag with its type.
102*/
103
104#define TValuefields	Value value_; int tt_
105
106typedef struct lua_TValue TValue;
107
108
109/* macro defining a nil value */
110#define NILCONSTANT	{NULL}, LUA_TNIL
111
112
113#define val_(o)		((o)->value_)
114#define num_(o)		(val_(o).n)
115
116
117/* raw type tag of a TValue */
118#define rttype(o)	((o)->tt_)
119
120/* tag with no variants (bits 0-3) */
121#define novariant(x)	((x) & 0x0F)
122
123/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
124#define ttype(o)	(rttype(o) & 0x3F)
125
126/* type tag of a TValue with no variants (bits 0-3) */
127#define ttypenv(o)	(novariant(rttype(o)))
128
129
130/* Macros to test type */
131#define checktag(o,t)		(rttype(o) == (t))
132#define checktype(o,t)		(ttypenv(o) == (t))
133#define ttisnumber(o)		checktag((o), LUA_TNUMBER)
134#define ttisnil(o)		checktag((o), LUA_TNIL)
135#define ttisboolean(o)		checktag((o), LUA_TBOOLEAN)
136#define ttislightuserdata(o)	checktag((o), LUA_TLIGHTUSERDATA)
137#define ttisstring(o)		checktype((o), LUA_TSTRING)
138#define ttisshrstring(o)	checktag((o), ctb(LUA_TSHRSTR))
139#define ttislngstring(o)	checktag((o), ctb(LUA_TLNGSTR))
140#define ttistable(o)		checktag((o), ctb(LUA_TTABLE))
141#define ttisfunction(o)		checktype(o, LUA_TFUNCTION)
142#define ttisclosure(o)		((rttype(o) & 0x1F) == LUA_TFUNCTION)
143#define ttisCclosure(o)		checktag((o), ctb(LUA_TCCL))
144#define ttisLclosure(o)		checktag((o), ctb(LUA_TLCL))
145#define ttislcf(o)		checktag((o), LUA_TLCF)
146#define ttisuserdata(o)		checktag((o), ctb(LUA_TUSERDATA))
147#define ttisthread(o)		checktag((o), ctb(LUA_TTHREAD))
148#define ttisdeadkey(o)		checktag((o), LUA_TDEADKEY)
149
150#define ttisequal(o1,o2)	(rttype(o1) == rttype(o2))
151
152/* Macros to access values */
153#define nvalue(o)	check_exp(ttisnumber(o), num_(o))
154#define gcvalue(o)	check_exp(iscollectable(o), val_(o).gc)
155#define pvalue(o)	check_exp(ttislightuserdata(o), val_(o).p)
156#define rawtsvalue(o)	check_exp(ttisstring(o), &val_(o).gc->ts)
157#define tsvalue(o)	(&rawtsvalue(o)->tsv)
158#define rawuvalue(o)	check_exp(ttisuserdata(o), &val_(o).gc->u)
159#define uvalue(o)	(&rawuvalue(o)->uv)
160#define clvalue(o)	check_exp(ttisclosure(o), &val_(o).gc->cl)
161#define clLvalue(o)	check_exp(ttisLclosure(o), &val_(o).gc->cl.l)
162#define clCvalue(o)	check_exp(ttisCclosure(o), &val_(o).gc->cl.c)
163#define fvalue(o)	check_exp(ttislcf(o), val_(o).f)
164#define hvalue(o)	check_exp(ttistable(o), &val_(o).gc->h)
165#define bvalue(o)	check_exp(ttisboolean(o), val_(o).b)
166#define thvalue(o)	check_exp(ttisthread(o), &val_(o).gc->th)
167/* a dead value may get the 'gc' field, but cannot access its contents */
168#define deadvalue(o)	check_exp(ttisdeadkey(o), cast(void *, val_(o).gc))
169
170#define l_isfalse(o)	(ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))
171
172
173#define iscollectable(o)	(rttype(o) & BIT_ISCOLLECTABLE)
174
175
176/* Macros for internal tests */
177#define righttt(obj)		(ttype(obj) == gcvalue(obj)->gch.tt)
178
179#define checkliveness(g,obj) \
180	lua_longassert(!iscollectable(obj) || \
181			(righttt(obj) && !isdead(g,gcvalue(obj))))
182
183
184/* Macros to set values */
185#define settt_(o,t)	((o)->tt_=(t))
186
187#define setnvalue(obj,x) \
188  { TValue *io=(obj); num_(io)=(x); settt_(io, LUA_TNUMBER); }
189
190#define setnilvalue(obj) settt_(obj, LUA_TNIL)
191
192#define setfvalue(obj,x) \
193  { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_TLCF); }
194
195#define setpvalue(obj,x) \
196  { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_TLIGHTUSERDATA); }
197
198#define setbvalue(obj,x) \
199  { TValue *io=(obj); val_(io).b=(x); settt_(io, LUA_TBOOLEAN); }
200
201#define setgcovalue(L,obj,x) \
202  { TValue *io=(obj); GCObject *i_g=(x); \
203    val_(io).gc=i_g; settt_(io, ctb(gch(i_g)->tt)); }
204
205#define setsvalue(L,obj,x) \
206  { TValue *io=(obj); \
207    TString *x_ = (x); \
208    val_(io).gc=cast(GCObject *, x_); settt_(io, ctb(x_->tsv.tt)); \
209    checkliveness(G(L),io); }
210
211#define setuvalue(L,obj,x) \
212  { TValue *io=(obj); \
213    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TUSERDATA)); \
214    checkliveness(G(L),io); }
215
216#define setthvalue(L,obj,x) \
217  { TValue *io=(obj); \
218    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TTHREAD)); \
219    checkliveness(G(L),io); }
220
221#define setclLvalue(L,obj,x) \
222  { TValue *io=(obj); \
223    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TLCL)); \
224    checkliveness(G(L),io); }
225
226#define setclCvalue(L,obj,x) \
227  { TValue *io=(obj); \
228    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TCCL)); \
229    checkliveness(G(L),io); }
230
231#define sethvalue(L,obj,x) \
232  { TValue *io=(obj); \
233    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TTABLE)); \
234    checkliveness(G(L),io); }
235
236#define setdeadvalue(obj)	settt_(obj, LUA_TDEADKEY)
237
238
239
240#define setobj(L,obj1,obj2) \
241	{ const TValue *io2=(obj2); TValue *io1=(obj1); \
242	  io1->value_ = io2->value_; io1->tt_ = io2->tt_; \
243	  checkliveness(G(L),io1); }
244
245
246/*
247** different types of assignments, according to destination
248*/
249
250/* from stack to (same) stack */
251#define setobjs2s	setobj
252/* to stack (not from same stack) */
253#define setobj2s	setobj
254#define setsvalue2s	setsvalue
255#define sethvalue2s	sethvalue
256#define setptvalue2s	setptvalue
257/* from table to same table */
258#define setobjt2t	setobj
259/* to table */
260#define setobj2t	setobj
261/* to new object */
262#define setobj2n	setobj
263#define setsvalue2n	setsvalue
264
265
266/* check whether a number is valid (useful only for NaN trick) */
267#define luai_checknum(L,o,c)	{ /* empty */ }
268
269
270/*
271** {======================================================
272** NaN Trick
273** =======================================================
274*/
275#if defined(LUA_NANTRICK)
276
277/*
278** numbers are represented in the 'd_' field. All other values have the
279** value (NNMARK | tag) in 'tt__'. A number with such pattern would be
280** a "signaled NaN", which is never generated by regular operations by
281** the CPU (nor by 'strtod')
282*/
283
284/* allows for external implementation for part of the trick */
285#if !defined(NNMARK)	/* { */
286
287
288#if !defined(LUA_IEEEENDIAN)
289#error option 'LUA_NANTRICK' needs 'LUA_IEEEENDIAN'
290#endif
291
292
293#define NNMARK		0x7FF7A500
294#define NNMASK		0x7FFFFF00
295
296#undef TValuefields
297#undef NILCONSTANT
298
299#if (LUA_IEEEENDIAN == 0)	/* { */
300
301/* little endian */
302#define TValuefields  \
303	union { struct { Value v__; int tt__; } i; double d__; } u
304#define NILCONSTANT	{{{NULL}, tag2tt(LUA_TNIL)}}
305/* field-access macros */
306#define v_(o)		((o)->u.i.v__)
307#define d_(o)		((o)->u.d__)
308#define tt_(o)		((o)->u.i.tt__)
309
310#else				/* }{ */
311
312/* big endian */
313#define TValuefields  \
314	union { struct { int tt__; Value v__; } i; double d__; } u
315#define NILCONSTANT	{{tag2tt(LUA_TNIL), {NULL}}}
316/* field-access macros */
317#define v_(o)		((o)->u.i.v__)
318#define d_(o)		((o)->u.d__)
319#define tt_(o)		((o)->u.i.tt__)
320
321#endif				/* } */
322
323#endif			/* } */
324
325
326/* correspondence with standard representation */
327#undef val_
328#define val_(o)		v_(o)
329#undef num_
330#define num_(o)		d_(o)
331
332
333#undef numfield
334#define numfield	/* no such field; numbers are the entire struct */
335
336/* basic check to distinguish numbers from non-numbers */
337#undef ttisnumber
338#define ttisnumber(o)	((tt_(o) & NNMASK) != NNMARK)
339
340#define tag2tt(t)	(NNMARK | (t))
341
342#undef rttype
343#define rttype(o)	(ttisnumber(o) ? LUA_TNUMBER : tt_(o) & 0xff)
344
345#undef settt_
346#define settt_(o,t)	(tt_(o) = tag2tt(t))
347
348#undef setnvalue
349#define setnvalue(obj,x) \
350	{ TValue *io_=(obj); num_(io_)=(x); lua_assert(ttisnumber(io_)); }
351
352#undef setobj
353#define setobj(L,obj1,obj2) \
354	{ const TValue *o2_=(obj2); TValue *o1_=(obj1); \
355	  o1_->u = o2_->u; \
356	  checkliveness(G(L),o1_); }
357
358
359/*
360** these redefinitions are not mandatory, but these forms are more efficient
361*/
362
363#undef checktag
364#undef checktype
365#define checktag(o,t)	(tt_(o) == tag2tt(t))
366#define checktype(o,t)	(ctb(tt_(o) | VARBITS) == ctb(tag2tt(t) | VARBITS))
367
368#undef ttisequal
369#define ttisequal(o1,o2)  \
370	(ttisnumber(o1) ? ttisnumber(o2) : (tt_(o1) == tt_(o2)))
371
372
373#undef luai_checknum
374#define luai_checknum(L,o,c)	{ if (!ttisnumber(o)) c; }
375
376#endif
377/* }====================================================== */
378
379
380
381/*
382** {======================================================
383** types and prototypes
384** =======================================================
385*/
386
387
388union Value {
389  GCObject *gc;    /* collectable objects */
390  void *p;         /* light userdata */
391  int b;           /* booleans */
392  lua_CFunction f; /* light C functions */
393  numfield         /* numbers */
394};
395
396
397struct lua_TValue {
398  TValuefields;
399};
400
401
402typedef TValue *StkId;  /* index to stack elements */
403
404
405
406
407/*
408** Header for string value; string bytes follow the end of this structure
409*/
410typedef union TString {
411  L_Umaxalign dummy;  /* ensures maximum alignment for strings */
412  struct {
413    CommonHeader;
414    lu_byte extra;  /* reserved words for short strings; "has hash" for longs */
415    unsigned int hash;
416    size_t len;  /* number of characters in string */
417  } tsv;
418} TString;
419
420
421/* get the actual string (array of bytes) from a TString */
422#define getstr(ts)	cast(const char *, (ts) + 1)
423
424/* get the actual string (array of bytes) from a Lua value */
425#define svalue(o)       getstr(rawtsvalue(o))
426
427
428/*
429** Header for userdata; memory area follows the end of this structure
430*/
431typedef union Udata {
432  L_Umaxalign dummy;  /* ensures maximum alignment for `local' udata */
433  struct {
434    CommonHeader;
435    struct Table *metatable;
436    struct Table *env;
437    size_t len;  /* number of bytes */
438  } uv;
439} Udata;
440
441
442
443/*
444** Description of an upvalue for function prototypes
445*/
446typedef struct Upvaldesc {
447  TString *name;  /* upvalue name (for debug information) */
448  lu_byte instack;  /* whether it is in stack */
449  lu_byte idx;  /* index of upvalue (in stack or in outer function's list) */
450} Upvaldesc;
451
452
453/*
454** Description of a local variable for function prototypes
455** (used for debug information)
456*/
457typedef struct LocVar {
458  TString *varname;
459  int startpc;  /* first point where variable is active */
460  int endpc;    /* first point where variable is dead */
461} LocVar;
462
463
464/*
465** Function Prototypes
466*/
467typedef struct Proto {
468  CommonHeader;
469  TValue *k;  /* constants used by the function */
470  Instruction *code;
471  struct Proto **p;  /* functions defined inside the function */
472  int *lineinfo;  /* map from opcodes to source lines (debug information) */
473  LocVar *locvars;  /* information about local variables (debug information) */
474  Upvaldesc *upvalues;  /* upvalue information */
475  union Closure *cache;  /* last created closure with this prototype */
476  TString  *source;  /* used for debug information */
477  int sizeupvalues;  /* size of 'upvalues' */
478  int sizek;  /* size of `k' */
479  int sizecode;
480  int sizelineinfo;
481  int sizep;  /* size of `p' */
482  int sizelocvars;
483  int linedefined;
484  int lastlinedefined;
485  GCObject *gclist;
486  lu_byte numparams;  /* number of fixed parameters */
487  lu_byte is_vararg;
488  lu_byte maxstacksize;  /* maximum stack used by this function */
489} Proto;
490
491
492
493/*
494** Lua Upvalues
495*/
496typedef struct UpVal {
497  CommonHeader;
498  TValue *v;  /* points to stack or to its own value */
499  union {
500    TValue value;  /* the value (when closed) */
501    struct {  /* double linked list (when open) */
502      struct UpVal *prev;
503      struct UpVal *next;
504    } l;
505  } u;
506} UpVal;
507
508
509/*
510** Closures
511*/
512
513#define ClosureHeader \
514	CommonHeader; lu_byte nupvalues; GCObject *gclist
515
516typedef struct CClosure {
517  ClosureHeader;
518  lua_CFunction f;
519  TValue upvalue[1];  /* list of upvalues */
520} CClosure;
521
522
523typedef struct LClosure {
524  ClosureHeader;
525  struct Proto *p;
526  UpVal *upvals[1];  /* list of upvalues */
527} LClosure;
528
529
530typedef union Closure {
531  CClosure c;
532  LClosure l;
533} Closure;
534
535
536#define isLfunction(o)	ttisLclosure(o)
537
538#define getproto(o)	(clLvalue(o)->p)
539
540
541/*
542** Tables
543*/
544
545typedef union TKey {
546  struct {
547    TValuefields;
548    struct Node *next;  /* for chaining */
549  } nk;
550  TValue tvk;
551} TKey;
552
553
554typedef struct Node {
555  TValue i_val;
556  TKey i_key;
557} Node;
558
559
560typedef struct Table {
561  CommonHeader;
562  lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
563  lu_byte lsizenode;  /* log2 of size of `node' array */
564  struct Table *metatable;
565  TValue *array;  /* array part */
566  Node *node;
567  Node *lastfree;  /* any free position is before this position */
568  GCObject *gclist;
569  int sizearray;  /* size of `array' array */
570} Table;
571
572
573
574/*
575** `module' operation for hashing (size is always a power of 2)
576*/
577#define lmod(s,size) \
578	(check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1)))))
579
580
581#define twoto(x)	(1<<(x))
582#define sizenode(t)	(twoto((t)->lsizenode))
583
584
585/*
586** (address of) a fixed nil value
587*/
588#define luaO_nilobject		(&luaO_nilobject_)
589
590
591LUAI_DDEC const TValue luaO_nilobject_;
592
593
594LUAI_FUNC int luaO_int2fb (unsigned int x);
595LUAI_FUNC int luaO_fb2int (int x);
596LUAI_FUNC int luaO_ceillog2 (unsigned int x);
597LUAI_FUNC lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2);
598LUAI_FUNC int luaO_str2d (const char *s, size_t len, lua_Number *result);
599LUAI_FUNC int luaO_hexavalue (int c);
600LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
601                                                       va_list argp);
602LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
603LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);
604
605
606#endif
607
608