1/*
2** $Id: lobject.h $
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 types for collectable non-values
21*/
22#define LUA_TUPVAL	LUA_NUMTYPES  /* upvalues */
23#define LUA_TPROTO	(LUA_NUMTYPES+1)  /* function prototypes */
24#define LUA_TDEADKEY	(LUA_NUMTYPES+2)  /* removed keys in tables */
25
26
27
28/*
29** number of all possible types (including LUA_TNONE but excluding DEADKEY)
30*/
31#define LUA_TOTALTYPES		(LUA_TPROTO + 2)
32
33
34/*
35** tags for Tagged Values have the following use of bits:
36** bits 0-3: actual tag (a LUA_T* constant)
37** bits 4-5: variant bits
38** bit 6: whether value is collectable
39*/
40
41/* add variant bits to a type */
42#define makevariant(t,v)	((t) | ((v) << 4))
43
44
45
46/*
47** Union of all Lua values
48*/
49typedef union Value {
50  struct GCObject *gc;    /* collectable objects */
51  void *p;         /* light userdata */
52  lua_CFunction f; /* light C functions */
53  lua_Integer i;   /* integer numbers */
54  lua_Number n;    /* float numbers */
55  /* not used, but may avoid warnings for uninitialized value */
56  lu_byte ub;
57} Value;
58
59
60/*
61** Tagged Values. This is the basic representation of values in Lua:
62** an actual value plus a tag with its type.
63*/
64
65#define TValuefields	Value value_; lu_byte tt_
66
67typedef struct TValue {
68  TValuefields;
69} TValue;
70
71
72#define val_(o)		((o)->value_)
73#define valraw(o)	(val_(o))
74
75
76/* raw type tag of a TValue */
77#define rawtt(o)	((o)->tt_)
78
79/* tag with no variants (bits 0-3) */
80#define novariant(t)	((t) & 0x0F)
81
82/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
83#define withvariant(t)	((t) & 0x3F)
84#define ttypetag(o)	withvariant(rawtt(o))
85
86/* type of a TValue */
87#define ttype(o)	(novariant(rawtt(o)))
88
89
90/* Macros to test type */
91#define checktag(o,t)		(rawtt(o) == (t))
92#define checktype(o,t)		(ttype(o) == (t))
93
94
95/* Macros for internal tests */
96
97/* collectable object has the same tag as the original value */
98#define righttt(obj)		(ttypetag(obj) == gcvalue(obj)->tt)
99
100/*
101** Any value being manipulated by the program either is non
102** collectable, or the collectable object has the right tag
103** and it is not dead. The option 'L == NULL' allows other
104** macros using this one to be used where L is not available.
105*/
106#define checkliveness(L,obj) \
107	((void)L, lua_longassert(!iscollectable(obj) || \
108		(righttt(obj) && (L == NULL || !isdead(G(L),gcvalue(obj))))))
109
110
111/* Macros to set values */
112
113/* set a value's tag */
114#define settt_(o,t)	((o)->tt_=(t))
115
116
117/* main macro to copy values (from 'obj2' to 'obj1') */
118#define setobj(L,obj1,obj2) \
119	{ TValue *io1=(obj1); const TValue *io2=(obj2); \
120          io1->value_ = io2->value_; settt_(io1, io2->tt_); \
121	  checkliveness(L,io1); lua_assert(!isnonstrictnil(io1)); }
122
123/*
124** Different types of assignments, according to source and destination.
125** (They are mostly equal now, but may be different in the future.)
126*/
127
128/* from stack to stack */
129#define setobjs2s(L,o1,o2)	setobj(L,s2v(o1),s2v(o2))
130/* to stack (not from same stack) */
131#define setobj2s(L,o1,o2)	setobj(L,s2v(o1),o2)
132/* from table to same table */
133#define setobjt2t	setobj
134/* to new object */
135#define setobj2n	setobj
136/* to table */
137#define setobj2t	setobj
138
139
140/*
141** Entries in a Lua stack. Field 'tbclist' forms a list of all
142** to-be-closed variables active in this stack. Dummy entries are
143** used when the distance between two tbc variables does not fit
144** in an unsigned short. They are represented by delta==0, and
145** their real delta is always the maximum value that fits in
146** that field.
147*/
148typedef union StackValue {
149  TValue val;
150  struct {
151    TValuefields;
152    unsigned short delta;
153  } tbclist;
154} StackValue;
155
156
157/* index to stack elements */
158typedef StackValue *StkId;
159
160
161/*
162** When reallocating the stack, change all pointers to the stack into
163** proper offsets.
164*/
165typedef union {
166  StkId p;  /* actual pointer */
167  ptrdiff_t offset;  /* used while the stack is being reallocated */
168} StkIdRel;
169
170
171/* convert a 'StackValue' to a 'TValue' */
172#define s2v(o)	(&(o)->val)
173
174
175
176/*
177** {==================================================================
178** Nil
179** ===================================================================
180*/
181
182/* Standard nil */
183#define LUA_VNIL	makevariant(LUA_TNIL, 0)
184
185/* Empty slot (which might be different from a slot containing nil) */
186#define LUA_VEMPTY	makevariant(LUA_TNIL, 1)
187
188/* Value returned for a key not found in a table (absent key) */
189#define LUA_VABSTKEY	makevariant(LUA_TNIL, 2)
190
191
192/* macro to test for (any kind of) nil */
193#define ttisnil(v)		checktype((v), LUA_TNIL)
194
195
196/* macro to test for a standard nil */
197#define ttisstrictnil(o)	checktag((o), LUA_VNIL)
198
199
200#define setnilvalue(obj) settt_(obj, LUA_VNIL)
201
202
203#define isabstkey(v)		checktag((v), LUA_VABSTKEY)
204
205
206/*
207** macro to detect non-standard nils (used only in assertions)
208*/
209#define isnonstrictnil(v)	(ttisnil(v) && !ttisstrictnil(v))
210
211
212/*
213** By default, entries with any kind of nil are considered empty.
214** (In any definition, values associated with absent keys must also
215** be accepted as empty.)
216*/
217#define isempty(v)		ttisnil(v)
218
219
220/* macro defining a value corresponding to an absent key */
221#define ABSTKEYCONSTANT		{NULL}, LUA_VABSTKEY
222
223
224/* mark an entry as empty */
225#define setempty(v)		settt_(v, LUA_VEMPTY)
226
227
228
229/* }================================================================== */
230
231
232/*
233** {==================================================================
234** Booleans
235** ===================================================================
236*/
237
238
239#define LUA_VFALSE	makevariant(LUA_TBOOLEAN, 0)
240#define LUA_VTRUE	makevariant(LUA_TBOOLEAN, 1)
241
242#define ttisboolean(o)		checktype((o), LUA_TBOOLEAN)
243#define ttisfalse(o)		checktag((o), LUA_VFALSE)
244#define ttistrue(o)		checktag((o), LUA_VTRUE)
245
246
247#define l_isfalse(o)	(ttisfalse(o) || ttisnil(o))
248
249
250#define setbfvalue(obj)		settt_(obj, LUA_VFALSE)
251#define setbtvalue(obj)		settt_(obj, LUA_VTRUE)
252
253/* }================================================================== */
254
255
256/*
257** {==================================================================
258** Threads
259** ===================================================================
260*/
261
262#define LUA_VTHREAD		makevariant(LUA_TTHREAD, 0)
263
264#define ttisthread(o)		checktag((o), ctb(LUA_VTHREAD))
265
266#define thvalue(o)	check_exp(ttisthread(o), gco2th(val_(o).gc))
267
268#define setthvalue(L,obj,x) \
269  { TValue *io = (obj); lua_State *x_ = (x); \
270    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VTHREAD)); \
271    checkliveness(L,io); }
272
273#define setthvalue2s(L,o,t)	setthvalue(L,s2v(o),t)
274
275/* }================================================================== */
276
277
278/*
279** {==================================================================
280** Collectable Objects
281** ===================================================================
282*/
283
284/*
285** Common Header for all collectable objects (in macro form, to be
286** included in other objects)
287*/
288#define CommonHeader	struct GCObject *next; lu_byte tt; lu_byte marked
289
290
291/* Common type for all collectable objects */
292typedef struct GCObject {
293  CommonHeader;
294} GCObject;
295
296
297/* Bit mark for collectable types */
298#define BIT_ISCOLLECTABLE	(1 << 6)
299
300#define iscollectable(o)	(rawtt(o) & BIT_ISCOLLECTABLE)
301
302/* mark a tag as collectable */
303#define ctb(t)			((t) | BIT_ISCOLLECTABLE)
304
305#define gcvalue(o)	check_exp(iscollectable(o), val_(o).gc)
306
307#define gcvalueraw(v)	((v).gc)
308
309#define setgcovalue(L,obj,x) \
310  { TValue *io = (obj); GCObject *i_g=(x); \
311    val_(io).gc = i_g; settt_(io, ctb(i_g->tt)); }
312
313/* }================================================================== */
314
315
316/*
317** {==================================================================
318** Numbers
319** ===================================================================
320*/
321
322/* Variant tags for numbers */
323#define LUA_VNUMINT	makevariant(LUA_TNUMBER, 0)  /* integer numbers */
324#define LUA_VNUMFLT	makevariant(LUA_TNUMBER, 1)  /* float numbers */
325
326#define ttisnumber(o)		checktype((o), LUA_TNUMBER)
327#define ttisfloat(o)		checktag((o), LUA_VNUMFLT)
328#define ttisinteger(o)		checktag((o), LUA_VNUMINT)
329
330#define nvalue(o)	check_exp(ttisnumber(o), \
331	(ttisinteger(o) ? cast_num(ivalue(o)) : fltvalue(o)))
332#define fltvalue(o)	check_exp(ttisfloat(o), val_(o).n)
333#define ivalue(o)	check_exp(ttisinteger(o), val_(o).i)
334
335#define fltvalueraw(v)	((v).n)
336#define ivalueraw(v)	((v).i)
337
338#define setfltvalue(obj,x) \
339  { TValue *io=(obj); val_(io).n=(x); settt_(io, LUA_VNUMFLT); }
340
341#define chgfltvalue(obj,x) \
342  { TValue *io=(obj); lua_assert(ttisfloat(io)); val_(io).n=(x); }
343
344#define setivalue(obj,x) \
345  { TValue *io=(obj); val_(io).i=(x); settt_(io, LUA_VNUMINT); }
346
347#define chgivalue(obj,x) \
348  { TValue *io=(obj); lua_assert(ttisinteger(io)); val_(io).i=(x); }
349
350/* }================================================================== */
351
352
353/*
354** {==================================================================
355** Strings
356** ===================================================================
357*/
358
359/* Variant tags for strings */
360#define LUA_VSHRSTR	makevariant(LUA_TSTRING, 0)  /* short strings */
361#define LUA_VLNGSTR	makevariant(LUA_TSTRING, 1)  /* long strings */
362
363#define ttisstring(o)		checktype((o), LUA_TSTRING)
364#define ttisshrstring(o)	checktag((o), ctb(LUA_VSHRSTR))
365#define ttislngstring(o)	checktag((o), ctb(LUA_VLNGSTR))
366
367#define tsvalueraw(v)	(gco2ts((v).gc))
368
369#define tsvalue(o)	check_exp(ttisstring(o), gco2ts(val_(o).gc))
370
371#define setsvalue(L,obj,x) \
372  { TValue *io = (obj); TString *x_ = (x); \
373    val_(io).gc = obj2gco(x_); settt_(io, ctb(x_->tt)); \
374    checkliveness(L,io); }
375
376/* set a string to the stack */
377#define setsvalue2s(L,o,s)	setsvalue(L,s2v(o),s)
378
379/* set a string to a new object */
380#define setsvalue2n	setsvalue
381
382
383/*
384** Header for a string value.
385*/
386typedef struct TString {
387  CommonHeader;
388  lu_byte extra;  /* reserved words for short strings; "has hash" for longs */
389  lu_byte shrlen;  /* length for short strings */
390  unsigned int hash;
391  union {
392    size_t lnglen;  /* length for long strings */
393    struct TString *hnext;  /* linked list for hash table */
394  } u;
395  char contents[1];
396} TString;
397
398
399
400/*
401** Get the actual string (array of bytes) from a 'TString'.
402*/
403#define getstr(ts)  ((ts)->contents)
404
405
406/* get the actual string (array of bytes) from a Lua value */
407#define svalue(o)       getstr(tsvalue(o))
408
409/* get string length from 'TString *s' */
410#define tsslen(s)	((s)->tt == LUA_VSHRSTR ? (s)->shrlen : (s)->u.lnglen)
411
412/* get string length from 'TValue *o' */
413#define vslen(o)	tsslen(tsvalue(o))
414
415/* }================================================================== */
416
417
418/*
419** {==================================================================
420** Userdata
421** ===================================================================
422*/
423
424
425/*
426** Light userdata should be a variant of userdata, but for compatibility
427** reasons they are also different types.
428*/
429#define LUA_VLIGHTUSERDATA	makevariant(LUA_TLIGHTUSERDATA, 0)
430
431#define LUA_VUSERDATA		makevariant(LUA_TUSERDATA, 0)
432
433#define ttislightuserdata(o)	checktag((o), LUA_VLIGHTUSERDATA)
434#define ttisfulluserdata(o)	checktag((o), ctb(LUA_VUSERDATA))
435
436#define pvalue(o)	check_exp(ttislightuserdata(o), val_(o).p)
437#define uvalue(o)	check_exp(ttisfulluserdata(o), gco2u(val_(o).gc))
438
439#define pvalueraw(v)	((v).p)
440
441#define setpvalue(obj,x) \
442  { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_VLIGHTUSERDATA); }
443
444#define setuvalue(L,obj,x) \
445  { TValue *io = (obj); Udata *x_ = (x); \
446    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VUSERDATA)); \
447    checkliveness(L,io); }
448
449
450/* Ensures that addresses after this type are always fully aligned. */
451typedef union UValue {
452  TValue uv;
453  LUAI_MAXALIGN;  /* ensures maximum alignment for udata bytes */
454} UValue;
455
456
457/*
458** Header for userdata with user values;
459** memory area follows the end of this structure.
460*/
461typedef struct Udata {
462  CommonHeader;
463  unsigned short nuvalue;  /* number of user values */
464  size_t len;  /* number of bytes */
465  struct Table *metatable;
466  GCObject *gclist;
467  UValue uv[1];  /* user values */
468} Udata;
469
470
471/*
472** Header for userdata with no user values. These userdata do not need
473** to be gray during GC, and therefore do not need a 'gclist' field.
474** To simplify, the code always use 'Udata' for both kinds of userdata,
475** making sure it never accesses 'gclist' on userdata with no user values.
476** This structure here is used only to compute the correct size for
477** this representation. (The 'bindata' field in its end ensures correct
478** alignment for binary data following this header.)
479*/
480typedef struct Udata0 {
481  CommonHeader;
482  unsigned short nuvalue;  /* number of user values */
483  size_t len;  /* number of bytes */
484  struct Table *metatable;
485  union {LUAI_MAXALIGN;} bindata;
486} Udata0;
487
488
489/* compute the offset of the memory area of a userdata */
490#define udatamemoffset(nuv) \
491	((nuv) == 0 ? offsetof(Udata0, bindata)  \
492                    : offsetof(Udata, uv) + (sizeof(UValue) * (nuv)))
493
494/* get the address of the memory block inside 'Udata' */
495#define getudatamem(u)	(cast_charp(u) + udatamemoffset((u)->nuvalue))
496
497/* compute the size of a userdata */
498#define sizeudata(nuv,nb)	(udatamemoffset(nuv) + (nb))
499
500/* }================================================================== */
501
502
503/*
504** {==================================================================
505** Prototypes
506** ===================================================================
507*/
508
509#define LUA_VPROTO	makevariant(LUA_TPROTO, 0)
510
511
512/*
513** Description of an upvalue for function prototypes
514*/
515typedef struct Upvaldesc {
516  TString *name;  /* upvalue name (for debug information) */
517  lu_byte instack;  /* whether it is in stack (register) */
518  lu_byte idx;  /* index of upvalue (in stack or in outer function's list) */
519  lu_byte kind;  /* kind of corresponding variable */
520} Upvaldesc;
521
522
523/*
524** Description of a local variable for function prototypes
525** (used for debug information)
526*/
527typedef struct LocVar {
528  TString *varname;
529  int startpc;  /* first point where variable is active */
530  int endpc;    /* first point where variable is dead */
531} LocVar;
532
533
534/*
535** Associates the absolute line source for a given instruction ('pc').
536** The array 'lineinfo' gives, for each instruction, the difference in
537** lines from the previous instruction. When that difference does not
538** fit into a byte, Lua saves the absolute line for that instruction.
539** (Lua also saves the absolute line periodically, to speed up the
540** computation of a line number: we can use binary search in the
541** absolute-line array, but we must traverse the 'lineinfo' array
542** linearly to compute a line.)
543*/
544typedef struct AbsLineInfo {
545  int pc;
546  int line;
547} AbsLineInfo;
548
549/*
550** Function Prototypes
551*/
552typedef struct Proto {
553  CommonHeader;
554  lu_byte numparams;  /* number of fixed (named) parameters */
555  lu_byte is_vararg;
556  lu_byte maxstacksize;  /* number of registers needed by this function */
557  int sizeupvalues;  /* size of 'upvalues' */
558  int sizek;  /* size of 'k' */
559  int sizecode;
560  int sizelineinfo;
561  int sizep;  /* size of 'p' */
562  int sizelocvars;
563  int sizeabslineinfo;  /* size of 'abslineinfo' */
564  int linedefined;  /* debug information  */
565  int lastlinedefined;  /* debug information  */
566  TValue *k;  /* constants used by the function */
567  Instruction *code;  /* opcodes */
568  struct Proto **p;  /* functions defined inside the function */
569  Upvaldesc *upvalues;  /* upvalue information */
570  ls_byte *lineinfo;  /* information about source lines (debug information) */
571  AbsLineInfo *abslineinfo;  /* idem */
572  LocVar *locvars;  /* information about local variables (debug information) */
573  TString  *source;  /* used for debug information */
574  GCObject *gclist;
575} Proto;
576
577/* }================================================================== */
578
579
580/*
581** {==================================================================
582** Functions
583** ===================================================================
584*/
585
586#define LUA_VUPVAL	makevariant(LUA_TUPVAL, 0)
587
588
589/* Variant tags for functions */
590#define LUA_VLCL	makevariant(LUA_TFUNCTION, 0)  /* Lua closure */
591#define LUA_VLCF	makevariant(LUA_TFUNCTION, 1)  /* light C function */
592#define LUA_VCCL	makevariant(LUA_TFUNCTION, 2)  /* C closure */
593
594#define ttisfunction(o)		checktype(o, LUA_TFUNCTION)
595#define ttisLclosure(o)		checktag((o), ctb(LUA_VLCL))
596#define ttislcf(o)		checktag((o), LUA_VLCF)
597#define ttisCclosure(o)		checktag((o), ctb(LUA_VCCL))
598#define ttisclosure(o)         (ttisLclosure(o) || ttisCclosure(o))
599
600
601#define isLfunction(o)	ttisLclosure(o)
602
603#define clvalue(o)	check_exp(ttisclosure(o), gco2cl(val_(o).gc))
604#define clLvalue(o)	check_exp(ttisLclosure(o), gco2lcl(val_(o).gc))
605#define fvalue(o)	check_exp(ttislcf(o), val_(o).f)
606#define clCvalue(o)	check_exp(ttisCclosure(o), gco2ccl(val_(o).gc))
607
608#define fvalueraw(v)	((v).f)
609
610#define setclLvalue(L,obj,x) \
611  { TValue *io = (obj); LClosure *x_ = (x); \
612    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VLCL)); \
613    checkliveness(L,io); }
614
615#define setclLvalue2s(L,o,cl)	setclLvalue(L,s2v(o),cl)
616
617#define setfvalue(obj,x) \
618  { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_VLCF); }
619
620#define setclCvalue(L,obj,x) \
621  { TValue *io = (obj); CClosure *x_ = (x); \
622    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VCCL)); \
623    checkliveness(L,io); }
624
625
626/*
627** Upvalues for Lua closures
628*/
629typedef struct UpVal {
630  CommonHeader;
631  union {
632    TValue *p;  /* points to stack or to its own value */
633    ptrdiff_t offset;  /* used while the stack is being reallocated */
634  } v;
635  union {
636    struct {  /* (when open) */
637      struct UpVal *next;  /* linked list */
638      struct UpVal **previous;
639    } open;
640    TValue value;  /* the value (when closed) */
641  } u;
642} UpVal;
643
644
645
646#define ClosureHeader \
647	CommonHeader; lu_byte nupvalues; GCObject *gclist
648
649typedef struct CClosure {
650  ClosureHeader;
651  lua_CFunction f;
652  TValue upvalue[1];  /* list of upvalues */
653} CClosure;
654
655
656typedef struct LClosure {
657  ClosureHeader;
658  struct Proto *p;
659  UpVal *upvals[1];  /* list of upvalues */
660} LClosure;
661
662
663typedef union Closure {
664  CClosure c;
665  LClosure l;
666} Closure;
667
668
669#define getproto(o)	(clLvalue(o)->p)
670
671/* }================================================================== */
672
673
674/*
675** {==================================================================
676** Tables
677** ===================================================================
678*/
679
680#define LUA_VTABLE	makevariant(LUA_TTABLE, 0)
681
682#define ttistable(o)		checktag((o), ctb(LUA_VTABLE))
683
684#define hvalue(o)	check_exp(ttistable(o), gco2t(val_(o).gc))
685
686#define sethvalue(L,obj,x) \
687  { TValue *io = (obj); Table *x_ = (x); \
688    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VTABLE)); \
689    checkliveness(L,io); }
690
691#define sethvalue2s(L,o,h)	sethvalue(L,s2v(o),h)
692
693
694/*
695** Nodes for Hash tables: A pack of two TValue's (key-value pairs)
696** plus a 'next' field to link colliding entries. The distribution
697** of the key's fields ('key_tt' and 'key_val') not forming a proper
698** 'TValue' allows for a smaller size for 'Node' both in 4-byte
699** and 8-byte alignments.
700*/
701typedef union Node {
702  struct NodeKey {
703    TValuefields;  /* fields for value */
704    lu_byte key_tt;  /* key type */
705    int next;  /* for chaining */
706    Value key_val;  /* key value */
707  } u;
708  TValue i_val;  /* direct access to node's value as a proper 'TValue' */
709} Node;
710
711
712/* copy a value into a key */
713#define setnodekey(L,node,obj) \
714	{ Node *n_=(node); const TValue *io_=(obj); \
715	  n_->u.key_val = io_->value_; n_->u.key_tt = io_->tt_; \
716	  checkliveness(L,io_); }
717
718
719/* copy a value from a key */
720#define getnodekey(L,obj,node) \
721	{ TValue *io_=(obj); const Node *n_=(node); \
722	  io_->value_ = n_->u.key_val; io_->tt_ = n_->u.key_tt; \
723	  checkliveness(L,io_); }
724
725
726/*
727** About 'alimit': if 'isrealasize(t)' is true, then 'alimit' is the
728** real size of 'array'. Otherwise, the real size of 'array' is the
729** smallest power of two not smaller than 'alimit' (or zero iff 'alimit'
730** is zero); 'alimit' is then used as a hint for #t.
731*/
732
733#define BITRAS		(1 << 7)
734#define isrealasize(t)		(!((t)->flags & BITRAS))
735#define setrealasize(t)		((t)->flags &= cast_byte(~BITRAS))
736#define setnorealasize(t)	((t)->flags |= BITRAS)
737
738
739typedef struct Table {
740  CommonHeader;
741  lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
742  lu_byte lsizenode;  /* log2 of size of 'node' array */
743  unsigned int alimit;  /* "limit" of 'array' array */
744  TValue *array;  /* array part */
745  Node *node;
746  Node *lastfree;  /* any free position is before this position */
747  struct Table *metatable;
748  GCObject *gclist;
749} Table;
750
751
752/*
753** Macros to manipulate keys inserted in nodes
754*/
755#define keytt(node)		((node)->u.key_tt)
756#define keyval(node)		((node)->u.key_val)
757
758#define keyisnil(node)		(keytt(node) == LUA_TNIL)
759#define keyisinteger(node)	(keytt(node) == LUA_VNUMINT)
760#define keyival(node)		(keyval(node).i)
761#define keyisshrstr(node)	(keytt(node) == ctb(LUA_VSHRSTR))
762#define keystrval(node)		(gco2ts(keyval(node).gc))
763
764#define setnilkey(node)		(keytt(node) = LUA_TNIL)
765
766#define keyiscollectable(n)	(keytt(n) & BIT_ISCOLLECTABLE)
767
768#define gckey(n)	(keyval(n).gc)
769#define gckeyN(n)	(keyiscollectable(n) ? gckey(n) : NULL)
770
771
772/*
773** Dead keys in tables have the tag DEADKEY but keep their original
774** gcvalue. This distinguishes them from regular keys but allows them to
775** be found when searched in a special way. ('next' needs that to find
776** keys removed from a table during a traversal.)
777*/
778#define setdeadkey(node)	(keytt(node) = LUA_TDEADKEY)
779#define keyisdead(node)		(keytt(node) == LUA_TDEADKEY)
780
781/* }================================================================== */
782
783
784
785/*
786** 'module' operation for hashing (size is always a power of 2)
787*/
788#define lmod(s,size) \
789	(check_exp((size&(size-1))==0, (cast_int((s) & ((size)-1)))))
790
791
792#define twoto(x)	(1<<(x))
793#define sizenode(t)	(twoto((t)->lsizenode))
794
795
796/* size of buffer for 'luaO_utf8esc' function */
797#define UTF8BUFFSZ	8
798
799LUAI_FUNC int luaO_utf8esc (char *buff, unsigned long x);
800LUAI_FUNC int luaO_ceillog2 (unsigned int x);
801LUAI_FUNC int luaO_rawarith (lua_State *L, int op, const TValue *p1,
802                             const TValue *p2, TValue *res);
803LUAI_FUNC void luaO_arith (lua_State *L, int op, const TValue *p1,
804                           const TValue *p2, StkId res);
805LUAI_FUNC size_t luaO_str2num (const char *s, TValue *o);
806LUAI_FUNC int luaO_hexavalue (int c);
807LUAI_FUNC void luaO_tostring (lua_State *L, TValue *obj);
808LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
809                                                       va_list argp);
810LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
811LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t srclen);
812
813
814#endif
815
816