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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   lu_byte extra;  /* reserved words for short strings; "has hash" for longs */
306   lu_byte shrlen;  /* length for short strings */
307   unsigned int hash;
308   union {
309     size_t lnglen;  /* length for long strings */
310     struct TString *hnext;  /* linked list for hash table */
311   } u;
312 } TString;
313 
314 
315 /*
316 ** Ensures that address after this type is always fully aligned.
317 */
318 typedef union UTString {
319   L_Umaxalign dummy;  /* ensures maximum alignment for strings */
320   TString tsv;
321 } UTString;
322 
323 
324 /*
325 ** Get the actual string (array of bytes) from a 'TString'.
326 ** (Access to 'extra' ensures that value is really a 'TString'.)
327 */
328 #define getstr(ts)  \
329   check_exp(sizeof((ts)->extra), cast(char *, (ts)) + sizeof(UTString))
330 
331 
332 /* get the actual string (array of bytes) from a Lua value */
333 #define svalue(o)       getstr(tsvalue(o))
334 
335 /* get string length from 'TString *s' */
336 #define tsslen(s)	((s)->tt == LUA_TSHRSTR ? (s)->shrlen : (s)->u.lnglen)
337 
338 /* get string length from 'TValue *o' */
339 #define vslen(o)	tsslen(tsvalue(o))
340 
341 
342 /*
343 ** Header for userdata; memory area follows the end of this structure
344 ** (aligned according to 'UUdata'; see next).
345 */
346 typedef struct Udata {
347   CommonHeader;
348   lu_byte ttuv_;  /* user value's tag */
349   struct Table *metatable;
350   size_t len;  /* number of bytes */
351   union Value user_;  /* user value */
352 } Udata;
353 
354 
355 /*
356 ** Ensures that address after this type is always fully aligned.
357 */
358 typedef union UUdata {
359   L_Umaxalign dummy;  /* ensures maximum alignment for 'local' udata */
360   Udata uv;
361 } UUdata;
362 
363 
364 /*
365 **  Get the address of memory block inside 'Udata'.
366 ** (Access to 'ttuv_' ensures that value is really a 'Udata'.)
367 */
368 #define getudatamem(u)  \
369   check_exp(sizeof((u)->ttuv_), (cast(char*, (u)) + sizeof(UUdata)))
370 
371 #define setuservalue(L,u,o) \
372 	{ const TValue *io=(o); Udata *iu = (u); \
373 	  iu->user_ = io->value_; iu->ttuv_ = rttype(io); \
374 	  checkliveness(L,io); }
375 
376 
377 #define getuservalue(L,u,o) \
378 	{ TValue *io=(o); const Udata *iu = (u); \
379 	  io->value_ = iu->user_; settt_(io, iu->ttuv_); \
380 	  checkliveness(L,io); }
381 
382 
383 /*
384 ** Description of an upvalue for function prototypes
385 */
386 typedef struct Upvaldesc {
387   TString *name;  /* upvalue name (for debug information) */
388   lu_byte instack;  /* whether it is in stack (register) */
389   lu_byte idx;  /* index of upvalue (in stack or in outer function's list) */
390 } Upvaldesc;
391 
392 
393 /*
394 ** Description of a local variable for function prototypes
395 ** (used for debug information)
396 */
397 typedef struct LocVar {
398   TString *varname;
399   int startpc;  /* first point where variable is active */
400   int endpc;    /* first point where variable is dead */
401 } LocVar;
402 
403 
404 /*
405 ** Function Prototypes
406 */
407 typedef struct Proto {
408   CommonHeader;
409   lu_byte numparams;  /* number of fixed parameters */
410   lu_byte is_vararg;
411   lu_byte maxstacksize;  /* number of registers needed by this function */
412   int sizeupvalues;  /* size of 'upvalues' */
413   int sizek;  /* size of 'k' */
414   int sizecode;
415   int sizelineinfo;
416   int sizep;  /* size of 'p' */
417   int sizelocvars;
418   int linedefined;  /* debug information  */
419   int lastlinedefined;  /* debug information  */
420   TValue *k;  /* constants used by the function */
421   Instruction *code;  /* opcodes */
422   struct Proto **p;  /* functions defined inside the function */
423   int *lineinfo;  /* map from opcodes to source lines (debug information) */
424   LocVar *locvars;  /* information about local variables (debug information) */
425   Upvaldesc *upvalues;  /* upvalue information */
426   struct LClosure *cache;  /* last-created closure with this prototype */
427   TString  *source;  /* used for debug information */
428   GCObject *gclist;
429 } Proto;
430 
431 
432 
433 /*
434 ** Lua Upvalues
435 */
436 typedef struct UpVal UpVal;
437 
438 
439 /*
440 ** Closures
441 */
442 
443 #define ClosureHeader \
444 	CommonHeader; lu_byte nupvalues; GCObject *gclist
445 
446 typedef struct CClosure {
447   ClosureHeader;
448   lua_CFunction f;
449   TValue upvalue[1];  /* list of upvalues */
450 } CClosure;
451 
452 
453 typedef struct LClosure {
454   ClosureHeader;
455   struct Proto *p;
456   UpVal *upvals[1];  /* list of upvalues */
457 } LClosure;
458 
459 
460 typedef union Closure {
461   CClosure c;
462   LClosure l;
463 } Closure;
464 
465 
466 #define isLfunction(o)	ttisLclosure(o)
467 
468 #define getproto(o)	(clLvalue(o)->p)
469 
470 
471 /*
472 ** Tables
473 */
474 
475 typedef union TKey {
476   struct {
477     TValuefields;
478     int next;  /* for chaining (offset for next node) */
479   } nk;
480   TValue tvk;
481 } TKey;
482 
483 
484 /* copy a value into a key without messing up field 'next' */
485 #define setnodekey(L,key,obj) \
486 	{ TKey *k_=(key); const TValue *io_=(obj); \
487 	  k_->nk.value_ = io_->value_; k_->nk.tt_ = io_->tt_; \
488 	  (void)L; checkliveness(L,io_); }
489 
490 
491 typedef struct Node {
492   TValue i_val;
493   TKey i_key;
494 } Node;
495 
496 
497 typedef struct Table {
498   CommonHeader;
499   lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
500   lu_byte lsizenode;  /* log2 of size of 'node' array */
501   unsigned int sizearray;  /* size of 'array' array */
502   TValue *array;  /* array part */
503   Node *node;
504   Node *lastfree;  /* any free position is before this position */
505   struct Table *metatable;
506   GCObject *gclist;
507 } Table;
508 
509 
510 
511 /*
512 ** 'module' operation for hashing (size is always a power of 2)
513 */
514 #define lmod(s,size) \
515 	(check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1)))))
516 
517 
518 #define twoto(x)	(1<<(x))
519 #define sizenode(t)	(twoto((t)->lsizenode))
520 
521 
522 /*
523 ** (address of) a fixed nil value
524 */
525 #define luaO_nilobject		(&luaO_nilobject_)
526 
527 
528 LUAI_DDEC const TValue luaO_nilobject_;
529 
530 /* size of buffer for 'luaO_utf8esc' function */
531 #define UTF8BUFFSZ	8
532 
533 LUAI_FUNC int luaO_int2fb (unsigned int x);
534 LUAI_FUNC int luaO_fb2int (int x);
535 LUAI_FUNC int luaO_utf8esc (char *buff, unsigned long x);
536 LUAI_FUNC int luaO_ceillog2 (unsigned int x);
537 LUAI_FUNC void luaO_arith (lua_State *L, int op, const TValue *p1,
538                            const TValue *p2, TValue *res);
539 LUAI_FUNC size_t luaO_str2num (const char *s, TValue *o);
540 LUAI_FUNC int luaO_hexavalue (int c);
541 LUAI_FUNC void luaO_tostring (lua_State *L, StkId obj);
542 LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
543                                                        va_list argp);
544 LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
545 LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);
546 
547 
548 #endif
549 
550