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