1 /*
2 ** $Id: lobject.h,v 2.20.1.2 2008/08/06 13:29:48 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 /* tags for values visible from Lua */
20 #define LAST_TAG    LUA_TTHREAD
21 
22 #define NUM_TAGS    (LAST_TAG+1)
23 
24 
25 /*
26 ** Extra tags for non-values
27 */
28 #define LUA_TPROTO  (LAST_TAG+1)
29 #define LUA_TUPVAL  (LAST_TAG+2)
30 #define LUA_TDEADKEY    (LAST_TAG+3)
31 
32 
33 /*
34 ** Union of all collectable objects
35 */
36 typedef union GCObject GCObject;
37 
38 
39 /*
40 ** Common Header for all collectable objects (in macro form, to be
41 ** included in other objects)
42 */
43 #define CommonHeader    GCObject *next; lu_byte tt; lu_byte marked
44 
45 
46 /*
47 ** Common header in struct form
48 */
49 typedef struct GCheader {
50   CommonHeader;
51 } GCheader;
52 
53 
54 
55 
56 /*
57 ** Union of all Lua values
58 */
59 typedef union {
60   GCObject *gc;
61   void *p;
62   lua_Number n;
63   int b;
64 } Value;
65 
66 
67 /*
68 ** Tagged Values
69 */
70 
71 #define TValuefields    Value value; int tt
72 
73 typedef struct lua_TValue {
74   TValuefields;
75 } TValue;
76 
77 
78 /* Macros to test type */
79 #define ttisnil(o)  (ttype(o) == LUA_TNIL)
80 #define ttisnumber(o)   (ttype(o) == LUA_TNUMBER)
81 #define ttisstring(o)   (ttype(o) == LUA_TSTRING)
82 #define ttistable(o)    (ttype(o) == LUA_TTABLE)
83 #define ttisfunction(o) (ttype(o) == LUA_TFUNCTION)
84 #define ttisboolean(o)  (ttype(o) == LUA_TBOOLEAN)
85 #define ttisuserdata(o) (ttype(o) == LUA_TUSERDATA)
86 #define ttisthread(o)   (ttype(o) == LUA_TTHREAD)
87 #define ttislightuserdata(o)    (ttype(o) == LUA_TLIGHTUSERDATA)
88 
89 /* Macros to access values */
90 #define ttype(o)    ((o)->tt)
91 #define gcvalue(o)  check_exp(iscollectable(o), (o)->value.gc)
92 #define pvalue(o)   check_exp(ttislightuserdata(o), (o)->value.p)
93 #define nvalue(o)   check_exp(ttisnumber(o), (o)->value.n)
94 #define rawtsvalue(o)   check_exp(ttisstring(o), &(o)->value.gc->ts)
95 #define tsvalue(o)  (&rawtsvalue(o)->tsv)
96 #define rawuvalue(o)    check_exp(ttisuserdata(o), &(o)->value.gc->u)
97 #define uvalue(o)   (&rawuvalue(o)->uv)
98 #define clvalue(o)  check_exp(ttisfunction(o), &(o)->value.gc->cl)
99 #define hvalue(o)   check_exp(ttistable(o), &(o)->value.gc->h)
100 #define bvalue(o)   check_exp(ttisboolean(o), (o)->value.b)
101 #define thvalue(o)  check_exp(ttisthread(o), &(o)->value.gc->th)
102 
103 #define l_isfalse(o)    (ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))
104 
105 /*
106 ** for internal debug only
107 */
108 #define checkconsistency(obj) \
109   lua_assert(!iscollectable(obj) || (ttype(obj) == (obj)->value.gc->gch.tt))
110 
111 #define checkliveness(g,obj) \
112   lua_assert(!iscollectable(obj) || \
113   ((ttype(obj) == (obj)->value.gc->gch.tt) && !isdead(g, (obj)->value.gc)))
114 
115 
116 /* Macros to set values */
117 #define setnilvalue(obj) ((obj)->tt=LUA_TNIL)
118 
119 #define setnvalue(obj,x) \
120   { TValue *i_o=(obj); i_o->value.n=(x); i_o->tt=LUA_TNUMBER; }
121 
122 #define setpvalue(obj,x) \
123   { TValue *i_o=(obj); i_o->value.p=(x); i_o->tt=LUA_TLIGHTUSERDATA; }
124 
125 #define setbvalue(obj,x) \
126   { TValue *i_o=(obj); i_o->value.b=(x); i_o->tt=LUA_TBOOLEAN; }
127 
128 #define setsvalue(L,obj,x) \
129   { TValue *i_o=(obj); \
130     i_o->value.gc=cast(GCObject *, (x)); i_o->tt=LUA_TSTRING; \
131     checkliveness(G(L),i_o); }
132 
133 #define setuvalue(L,obj,x) \
134   { TValue *i_o=(obj); \
135     i_o->value.gc=cast(GCObject *, (x)); i_o->tt=LUA_TUSERDATA; \
136     checkliveness(G(L),i_o); }
137 
138 #define setthvalue(L,obj,x) \
139   { TValue *i_o=(obj); \
140     i_o->value.gc=cast(GCObject *, (x)); i_o->tt=LUA_TTHREAD; \
141     checkliveness(G(L),i_o); }
142 
143 #define setclvalue(L,obj,x) \
144   { TValue *i_o=(obj); \
145     i_o->value.gc=cast(GCObject *, (x)); i_o->tt=LUA_TFUNCTION; \
146     checkliveness(G(L),i_o); }
147 
148 #define sethvalue(L,obj,x) \
149   { TValue *i_o=(obj); \
150     i_o->value.gc=cast(GCObject *, (x)); i_o->tt=LUA_TTABLE; \
151     checkliveness(G(L),i_o); }
152 
153 #define setptvalue(L,obj,x) \
154   { TValue *i_o=(obj); \
155     i_o->value.gc=cast(GCObject *, (x)); i_o->tt=LUA_TPROTO; \
156     checkliveness(G(L),i_o); }
157 
158 
159 
160 
161 #define setobj(L,obj1,obj2) \
162   { const TValue *o2=(obj2); TValue *o1=(obj1); \
163     o1->value = o2->value; o1->tt=o2->tt; \
164     checkliveness(G(L),o1); }
165 
166 
167 /*
168 ** different types of sets, according to destination
169 */
170 
171 /* from stack to (same) stack */
172 #define setobjs2s   setobj
173 /* to stack (not from same stack) */
174 #define setobj2s    setobj
175 #define setsvalue2s setsvalue
176 #define sethvalue2s sethvalue
177 #define setptvalue2s    setptvalue
178 /* from table to same table */
179 #define setobjt2t   setobj
180 /* to table */
181 #define setobj2t    setobj
182 /* to new object */
183 #define setobj2n    setobj
184 #define setsvalue2n setsvalue
185 
186 #define setttype(obj, tt) (ttype(obj) = (tt))
187 
188 
189 #define iscollectable(o)    (ttype(o) >= LUA_TSTRING)
190 
191 
192 
193 typedef TValue *StkId;  /* index to stack elements */
194 
195 
196 /*
197 ** String headers for string table
198 */
199 typedef union TString {
200   L_Umaxalign dummy;  /* ensures maximum alignment for strings */
201   struct {
202     CommonHeader;
203     lu_byte reserved;
204     unsigned int hash;
205     size_t len;
206   } tsv;
207 } TString;
208 
209 
210 #define getstr(ts)  cast(const char *, (ts) + 1)
211 #define svalue(o)       getstr(rawtsvalue(o))
212 
213 
214 
215 typedef union Udata {
216   L_Umaxalign dummy;  /* ensures maximum alignment for `local' udata */
217   struct {
218     CommonHeader;
219     struct Table *metatable;
220     struct Table *env;
221     size_t len;
222   } uv;
223 } Udata;
224 
225 
226 
227 
228 /*
229 ** Function Prototypes
230 */
231 typedef struct Proto {
232   CommonHeader;
233   TValue *k;  /* constants used by the function */
234   Instruction *code;
235   struct Proto **p;  /* functions defined inside the function */
236   int *lineinfo;  /* map from opcodes to source lines */
237   struct LocVar *locvars;  /* information about local variables */
238   TString **upvalues;  /* upvalue names */
239   TString  *source;
240   int sizeupvalues;
241   int sizek;  /* size of `k' */
242   int sizecode;
243   int sizelineinfo;
244   int sizep;  /* size of `p' */
245   int sizelocvars;
246   int linedefined;
247   int lastlinedefined;
248   GCObject *gclist;
249   lu_byte nups;  /* number of upvalues */
250   lu_byte numparams;
251   lu_byte is_vararg;
252   lu_byte maxstacksize;
253 } Proto;
254 
255 
256 /* masks for new-style vararg */
257 #define VARARG_HASARG       1
258 #define VARARG_ISVARARG     2
259 #define VARARG_NEEDSARG     4
260 
261 
262 typedef struct LocVar {
263   TString *varname;
264   int startpc;  /* first point where variable is active */
265   int endpc;    /* first point where variable is dead */
266 } LocVar;
267 
268 
269 
270 /*
271 ** Upvalues
272 */
273 
274 typedef struct UpVal {
275   CommonHeader;
276   TValue *v;  /* points to stack or to its own value */
277   union {
278     TValue value;  /* the value (when closed) */
279     struct {  /* double linked list (when open) */
280       struct UpVal *prev;
281       struct UpVal *next;
282     } l;
283   } u;
284 } UpVal;
285 
286 
287 /*
288 ** Closures
289 */
290 
291 #define ClosureHeader \
292     CommonHeader; lu_byte isC; lu_byte nupvalues; GCObject *gclist; \
293     struct Table *env
294 
295 typedef struct CClosure {
296   ClosureHeader;
297   lua_CFunction f;
298   TValue upvalue[1];
299 } CClosure;
300 
301 
302 typedef struct LClosure {
303   ClosureHeader;
304   struct Proto *p;
305   UpVal *upvals[1];
306 } LClosure;
307 
308 
309 typedef union Closure {
310   CClosure c;
311   LClosure l;
312 } Closure;
313 
314 
315 #define iscfunction(o)  (ttype(o) == LUA_TFUNCTION && clvalue(o)->c.isC)
316 #define isLfunction(o)  (ttype(o) == LUA_TFUNCTION && !clvalue(o)->c.isC)
317 
318 
319 /*
320 ** Tables
321 */
322 
323 typedef union TKey {
324   struct {
325     TValuefields;
326     struct Node *next;  /* for chaining */
327   } nk;
328   TValue tvk;
329 } TKey;
330 
331 
332 typedef struct Node {
333   TValue i_val;
334   TKey i_key;
335 } Node;
336 
337 
338 typedef struct Table {
339   CommonHeader;
340   lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
341   lu_byte lsizenode;  /* log2 of size of `node' array */
342   struct Table *metatable;
343   TValue *array;  /* array part */
344   Node *node;
345   Node *lastfree;  /* any free position is before this position */
346   GCObject *gclist;
347   int sizearray;  /* size of `array' array */
348 } Table;
349 
350 
351 
352 /*
353 ** `module' operation for hashing (size is always a power of 2)
354 */
355 #define lmod(s,size) \
356     (check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1)))))
357 
358 
359 #define twoto(x)    (1<<(x))
360 #define sizenode(t) (twoto((t)->lsizenode))
361 
362 
363 #define luaO_nilobject      (&luaO_nilobject_)
364 
365 LUAI_DATA const TValue luaO_nilobject_;
366 
367 #define ceillog2(x) (luaO_log2((x)-1) + 1)
368 
369 LUAI_FUNC int luaO_log2 (unsigned int x);
370 LUAI_FUNC int luaO_int2fb (unsigned int x);
371 LUAI_FUNC int luaO_fb2int (int x);
372 LUAI_FUNC int luaO_rawequalObj (const TValue *t1, const TValue *t2);
373 LUAI_FUNC int luaO_str2d (const char *s, lua_Number *result);
374 LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
375                                                        va_list argp);
376 LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
377 LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);
378 
379 
380 #endif
381 
382