1 /*
2 ** $Id: lobject.h,v 2.71.1.1 2013/04/12 18:48:47 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 */
70 typedef 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 */
83 typedef struct GCheader {
84   CommonHeader;
85 } GCheader;
86 
87 
88 
89 /*
90 ** Union of all Lua values
91 */
92 typedef 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 
106 typedef 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 
388 union 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 
397 struct lua_TValue {
398   TValuefields;
399 };
400 
401 
402 typedef 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 */
410 typedef 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 */
431 typedef 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 */
446 typedef 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 */
457 typedef 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 */
467 typedef 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 */
496 typedef 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 
516 typedef struct CClosure {
517   ClosureHeader;
518   lua_CFunction f;
519   TValue upvalue[1];  /* list of upvalues */
520 } CClosure;
521 
522 
523 typedef struct LClosure {
524   ClosureHeader;
525   struct Proto *p;
526   UpVal *upvals[1];  /* list of upvalues */
527 } LClosure;
528 
529 
530 typedef 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 
545 typedef union TKey {
546   struct {
547     TValuefields;
548     struct Node *next;  /* for chaining */
549   } nk;
550   TValue tvk;
551 } TKey;
552 
553 
554 typedef struct Node {
555   TValue i_val;
556   TKey i_key;
557 } Node;
558 
559 
560 typedef 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 
591 LUAI_DDEC const TValue luaO_nilobject_;
592 
593 
594 LUAI_FUNC int luaO_int2fb (unsigned int x);
595 LUAI_FUNC int luaO_fb2int (int x);
596 LUAI_FUNC int luaO_ceillog2 (unsigned int x);
597 LUAI_FUNC lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2);
598 LUAI_FUNC int luaO_str2d (const char *s, size_t len, lua_Number *result);
599 LUAI_FUNC int luaO_hexavalue (int c);
600 LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
601                                                        va_list argp);
602 LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
603 LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);
604 
605 
606 #endif
607 
608