1 /*
2 ** $Id: lobject.c,v 2.101 2014/12/26 14:43:45 roberto Exp $
3 ** Some generic functions over Lua objects
4 ** See Copyright Notice in lua.h
5 */
6
7 #define lobject_c
8 #define LUA_CORE
9
10 #include "lprefix.h"
11
12
13 #include <stdarg.h>
14 #include <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17
18 #include "lua.h"
19
20 #include "lctype.h"
21 #include "ldebug.h"
22 #include "ldo.h"
23 #include "lmem.h"
24 #include "lobject.h"
25 #include "lstate.h"
26 #include "lstring.h"
27 #include "lvm.h"
28
29
30
31 LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
32
33
34 /*
35 ** converts an integer to a "floating point byte", represented as
36 ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
37 ** eeeee != 0 and (xxx) otherwise.
38 */
luaO_int2fb(unsigned int x)39 int luaO_int2fb (unsigned int x) {
40 int e = 0; /* exponent */
41 if (x < 8) return x;
42 while (x >= 0x10) {
43 x = (x+1) >> 1;
44 e++;
45 }
46 return ((e+1) << 3) | (cast_int(x) - 8);
47 }
48
49
50 /* converts back */
luaO_fb2int(int x)51 int luaO_fb2int (int x) {
52 int e = (x >> 3) & 0x1f;
53 if (e == 0) return x;
54 else return ((x & 7) + 8) << (e - 1);
55 }
56
57
luaO_ceillog2(unsigned int x)58 int luaO_ceillog2 (unsigned int x) {
59 static const lu_byte log_2[256] = {
60 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
61 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
62 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
63 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
64 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
65 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
66 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
67 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
68 };
69 int l = 0;
70 x--;
71 while (x >= 256) { l += 8; x >>= 8; }
72 return l + log_2[x];
73 }
74
75
intarith(lua_State * L,int op,lua_Integer v1,lua_Integer v2)76 static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
77 lua_Integer v2) {
78 switch (op) {
79 case LUA_OPADD: return intop(+, v1, v2);
80 case LUA_OPSUB:return intop(-, v1, v2);
81 case LUA_OPMUL:return intop(*, v1, v2);
82 case LUA_OPMOD: return luaV_mod(L, v1, v2);
83 case LUA_OPIDIV: return luaV_div(L, v1, v2);
84 case LUA_OPBAND: return intop(&, v1, v2);
85 case LUA_OPBOR: return intop(|, v1, v2);
86 case LUA_OPBXOR: return intop(^, v1, v2);
87 case LUA_OPSHL: return luaV_shiftl(v1, v2);
88 case LUA_OPSHR: return luaV_shiftl(v1, -v2);
89 case LUA_OPUNM: return intop(-, 0, v1);
90 case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
91 default: lua_assert(0); return 0;
92 }
93 }
94
95
numarith(lua_State * L,int op,lua_Number v1,lua_Number v2)96 static lua_Number numarith (lua_State *L, int op, lua_Number v1,
97 lua_Number v2) {
98 switch (op) {
99 case LUA_OPADD: return luai_numadd(L, v1, v2);
100 case LUA_OPSUB: return luai_numsub(L, v1, v2);
101 case LUA_OPMUL: return luai_nummul(L, v1, v2);
102 case LUA_OPDIV: return luai_numdiv(L, v1, v2);
103 case LUA_OPPOW: return luai_numpow(L, v1, v2);
104 case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
105 case LUA_OPUNM: return luai_numunm(L, v1);
106 case LUA_OPMOD: {
107 lua_Number m;
108 luai_nummod(L, v1, v2, m);
109 return m;
110 }
111 default: lua_assert(0); return 0;
112 }
113 }
114
115
luaO_arith(lua_State * L,int op,const TValue * p1,const TValue * p2,TValue * res)116 void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
117 TValue *res) {
118 switch (op) {
119 case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
120 case LUA_OPSHL: case LUA_OPSHR:
121 case LUA_OPBNOT: { /* operate only on integers */
122 lua_Integer i1; lua_Integer i2;
123 if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
124 setivalue(res, intarith(L, op, i1, i2));
125 return;
126 }
127 else break; /* go to the end */
128 }
129 case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */
130 lua_Number n1; lua_Number n2;
131 if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
132 setfltvalue(res, numarith(L, op, n1, n2));
133 return;
134 }
135 else break; /* go to the end */
136 }
137 default: { /* other operations */
138 lua_Number n1; lua_Number n2;
139 if (ttisinteger(p1) && ttisinteger(p2)) {
140 setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
141 return;
142 }
143 else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
144 setfltvalue(res, numarith(L, op, n1, n2));
145 return;
146 }
147 else break; /* go to the end */
148 }
149 }
150 /* could not perform raw operation; try metamethod */
151 lua_assert(L != NULL); /* should not fail when folding (compile time) */
152 luaT_trybinTM(L, p1, p2, res, cast(TMS, op - LUA_OPADD + TM_ADD));
153 }
154
155
luaO_hexavalue(int c)156 int luaO_hexavalue (int c) {
157 if (lisdigit(c)) return c - '0';
158 else return ltolower(c) - 'a' + 10;
159 }
160
161
isneg(const char ** s)162 static int isneg (const char **s) {
163 if (**s == '-') { (*s)++; return 1; }
164 else if (**s == '+') (*s)++;
165 return 0;
166 }
167
168
169
170 /*
171 ** {==================================================================
172 ** Lua's implementation for 'lua_strx2number'
173 ** ===================================================================
174 */
175 #if !defined(lua_strx2number)
176
177 #include <math.h>
178
179 /* maximum number of significant digits to read (to avoid overflows
180 even with single floats) */
181 #define MAXSIGDIG 30
182
183 /*
184 ** convert an hexadecimal numeric string to a number, following
185 ** C99 specification for 'strtod'
186 */
lua_strx2number(const char * s,char ** endptr)187 static lua_Number lua_strx2number (const char *s, char **endptr) {
188 lua_Number r = 0.0; /* result (accumulator) */
189 int sigdig = 0; /* number of significant digits */
190 int nosigdig = 0; /* number of non-significant digits */
191 int e = 0; /* exponent correction */
192 int neg; /* 1 if number is negative */
193 int dot = 0; /* true after seen a dot */
194 *endptr = cast(char *, s); /* nothing is valid yet */
195 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
196 neg = isneg(&s); /* check signal */
197 if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */
198 return 0.0; /* invalid format (no '0x') */
199 for (s += 2; ; s++) { /* skip '0x' and read numeral */
200 if (*s == '.') {
201 if (dot) break; /* second dot? stop loop */
202 else dot = 1;
203 }
204 else if (lisxdigit(cast_uchar(*s))) {
205 if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */
206 nosigdig++;
207 else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */
208 r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
209 else e++; /* too many digits; ignore, but still count for exponent */
210 if (dot) e--; /* decimal digit? correct exponent */
211 }
212 else break; /* neither a dot nor a digit */
213 }
214 if (nosigdig + sigdig == 0) /* no digits? */
215 return 0.0; /* invalid format */
216 *endptr = cast(char *, s); /* valid up to here */
217 e *= 4; /* each digit multiplies/divides value by 2^4 */
218 if (*s == 'p' || *s == 'P') { /* exponent part? */
219 int exp1 = 0; /* exponent value */
220 int neg1; /* exponent signal */
221 s++; /* skip 'p' */
222 neg1 = isneg(&s); /* signal */
223 if (!lisdigit(cast_uchar(*s)))
224 return 0.0; /* invalid; must have at least one digit */
225 while (lisdigit(cast_uchar(*s))) /* read exponent */
226 exp1 = exp1 * 10 + *(s++) - '0';
227 if (neg1) exp1 = -exp1;
228 e += exp1;
229 *endptr = cast(char *, s); /* valid up to here */
230 }
231 if (neg) r = -r;
232 return l_mathop(ldexp)(r, e);
233 }
234
235 #endif
236 /* }====================================================== */
237
238
l_str2d(const char * s,lua_Number * result)239 static const char *l_str2d (const char *s, lua_Number *result) {
240 char *endptr;
241 if (strpbrk(s, "nN")) /* reject 'inf' and 'nan' */
242 return NULL;
243 else if (strpbrk(s, "xX")) /* hex? */
244 *result = lua_strx2number(s, &endptr);
245 else
246 *result = lua_str2number(s, &endptr);
247 if (endptr == s) return 0; /* nothing recognized */
248 while (lisspace(cast_uchar(*endptr))) endptr++;
249 return (*endptr == '\0' ? endptr : NULL); /* OK if no trailing characters */
250 }
251
252
l_str2int(const char * s,lua_Integer * result)253 static const char *l_str2int (const char *s, lua_Integer *result) {
254 lua_Unsigned a = 0;
255 int empty = 1;
256 int neg;
257 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
258 neg = isneg(&s);
259 if (s[0] == '0' &&
260 (s[1] == 'x' || s[1] == 'X')) { /* hex? */
261 s += 2; /* skip '0x' */
262 for (; lisxdigit(cast_uchar(*s)); s++) {
263 a = a * 16 + luaO_hexavalue(*s);
264 empty = 0;
265 }
266 }
267 else { /* decimal */
268 for (; lisdigit(cast_uchar(*s)); s++) {
269 a = a * 10 + *s - '0';
270 empty = 0;
271 }
272 }
273 while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */
274 if (empty || *s != '\0') return NULL; /* something wrong in the numeral */
275 else {
276 *result = l_castU2S((neg) ? 0u - a : a);
277 return s;
278 }
279 }
280
281
luaO_str2num(const char * s,TValue * o)282 size_t luaO_str2num (const char *s, TValue *o) {
283 lua_Integer i; lua_Number n;
284 const char *e;
285 if ((e = l_str2int(s, &i)) != NULL) { /* try as an integer */
286 setivalue(o, i);
287 }
288 else if ((e = l_str2d(s, &n)) != NULL) { /* else try as a float */
289 setfltvalue(o, n);
290 }
291 else
292 return 0; /* conversion failed */
293 return (e - s + 1); /* success; return string size */
294 }
295
296
luaO_utf8esc(char * buff,unsigned long x)297 int luaO_utf8esc (char *buff, unsigned long x) {
298 int n = 1; /* number of bytes put in buffer (backwards) */
299 lua_assert(x <= 0x10FFFF);
300 if (x < 0x80) /* ascii? */
301 buff[UTF8BUFFSZ - 1] = cast(char, x);
302 else { /* need continuation bytes */
303 unsigned int mfb = 0x3f; /* maximum that fits in first byte */
304 do { /* add continuation bytes */
305 buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
306 x >>= 6; /* remove added bits */
307 mfb >>= 1; /* now there is one less bit available in first byte */
308 } while (x > mfb); /* still needs continuation byte? */
309 buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x); /* add first byte */
310 }
311 return n;
312 }
313
314
315 /* maximum length of the conversion of a number to a string */
316 #define MAXNUMBER2STR 50
317
318
319 /*
320 ** Convert a number object to a string
321 */
luaO_tostring(lua_State * L,StkId obj)322 void luaO_tostring (lua_State *L, StkId obj) {
323 char buff[MAXNUMBER2STR];
324 size_t len;
325 lua_assert(ttisnumber(obj));
326 if (ttisinteger(obj))
327 len = lua_integer2str(buff, ivalue(obj));
328 else {
329 len = lua_number2str(buff, fltvalue(obj));
330 #if !defined(LUA_COMPAT_FLOATSTRING)
331 if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */
332 buff[len++] = '.';
333 buff[len++] = '0'; /* adds '.0' to result */
334 }
335 #endif
336 }
337 setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
338 }
339
340
pushstr(lua_State * L,const char * str,size_t l)341 static void pushstr (lua_State *L, const char *str, size_t l) {
342 setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
343 }
344
345
346 /* this function handles only '%d', '%c', '%f', '%p', and '%s'
347 conventional formats, plus Lua-specific '%I' and '%U' */
luaO_pushvfstring(lua_State * L,const char * fmt,va_list argp)348 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
349 int n = 0;
350 for (;;) {
351 const char *e = strchr(fmt, '%');
352 if (e == NULL) break;
353 luaD_checkstack(L, 2); /* fmt + item */
354 pushstr(L, fmt, e - fmt);
355 switch (*(e+1)) {
356 case 's': {
357 const char *s = va_arg(argp, char *);
358 if (s == NULL) s = "(null)";
359 pushstr(L, s, strlen(s));
360 break;
361 }
362 case 'c': {
363 char buff = cast(char, va_arg(argp, int));
364 if (lisprint(cast_uchar(buff)))
365 pushstr(L, &buff, 1);
366 else /* non-printable character; print its code */
367 luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
368 break;
369 }
370 case 'd': {
371 setivalue(L->top++, va_arg(argp, int));
372 luaO_tostring(L, L->top - 1);
373 break;
374 }
375 case 'I': {
376 setivalue(L->top++, cast(lua_Integer, va_arg(argp, l_uacInt)));
377 luaO_tostring(L, L->top - 1);
378 break;
379 }
380 case 'f': {
381 setfltvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
382 luaO_tostring(L, L->top - 1);
383 break;
384 }
385 case 'p': {
386 char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
387 int l = sprintf(buff, "%p", va_arg(argp, void *));
388 pushstr(L, buff, l);
389 break;
390 }
391 case 'U': {
392 char buff[UTF8BUFFSZ];
393 int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
394 pushstr(L, buff + UTF8BUFFSZ - l, l);
395 break;
396 }
397 case '%': {
398 pushstr(L, "%", 1);
399 break;
400 }
401 default: {
402 luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
403 *(e + 1));
404 }
405 }
406 n += 2;
407 fmt = e+2;
408 }
409 luaD_checkstack(L, 1);
410 pushstr(L, fmt, strlen(fmt));
411 if (n > 0) luaV_concat(L, n + 1);
412 return svalue(L->top - 1);
413 }
414
415
luaO_pushfstring(lua_State * L,const char * fmt,...)416 const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
417 const char *msg;
418 va_list argp;
419 va_start(argp, fmt);
420 msg = luaO_pushvfstring(L, fmt, argp);
421 va_end(argp);
422 return msg;
423 }
424
425
426 /* number of chars of a literal string without the ending \0 */
427 #define LL(x) (sizeof(x)/sizeof(char) - 1)
428
429 #define RETS "..."
430 #define PRE "[string \""
431 #define POS "\"]"
432
433 #define addstr(a,b,l) ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
434
luaO_chunkid(char * out,const char * source,size_t bufflen)435 void luaO_chunkid (char *out, const char *source, size_t bufflen) {
436 size_t l = strlen(source);
437 if (*source == '=') { /* 'literal' source */
438 if (l <= bufflen) /* small enough? */
439 memcpy(out, source + 1, l * sizeof(char));
440 else { /* truncate it */
441 addstr(out, source + 1, bufflen - 1);
442 *out = '\0';
443 }
444 }
445 else if (*source == '@') { /* file name */
446 if (l <= bufflen) /* small enough? */
447 memcpy(out, source + 1, l * sizeof(char));
448 else { /* add '...' before rest of name */
449 addstr(out, RETS, LL(RETS));
450 bufflen -= LL(RETS);
451 memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
452 }
453 }
454 else { /* string; format as [string "source"] */
455 const char *nl = strchr(source, '\n'); /* find first new line (if any) */
456 addstr(out, PRE, LL(PRE)); /* add prefix */
457 bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */
458 if (l < bufflen && nl == NULL) { /* small one-line source? */
459 addstr(out, source, l); /* keep it */
460 }
461 else {
462 if (nl != NULL) l = nl - source; /* stop at first newline */
463 if (l > bufflen) l = bufflen;
464 addstr(out, source, l);
465 addstr(out, RETS, LL(RETS));
466 }
467 memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
468 }
469 }
470
471