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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