1 /*
2 ** $Id: lobject.c,v 2.108 2015/11/02 16:09:30 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 <locale.h>
14 #include <math.h>
15 #include <stdarg.h>
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <string.h>
19
20 #include "lua.h"
21
22 #include "lctype.h"
23 #include "ldebug.h"
24 #include "ldo.h"
25 #include "lmem.h"
26 #include "lobject.h"
27 #include "lstate.h"
28 #include "lstring.h"
29 #include "lvm.h"
30
31
32
33 LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
34
35
36 /*
37 ** converts an integer to a "floating point byte", represented as
38 ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
39 ** eeeee != 0 and (xxx) otherwise.
40 */
41 int luaO_int2fb (unsigned int x) {
42 int e = 0; /* exponent */
43 if (x < 8) return x;
44 while (x >= (8 << 4)) { /* coarse steps */
45 x = (x + 0xf) >> 4; /* x = ceil(x / 16) */
46 e += 4;
47 }
48 while (x >= (8 << 1)) { /* fine steps */
49 x = (x + 1) >> 1; /* x = ceil(x / 2) */
50 e++;
51 }
52 return ((e+1) << 3) | (cast_int(x) - 8);
53 }
54
55
56 /* converts back */
57 int luaO_fb2int (int x) {
58 return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1);
59 }
60
61
62 /*
63 ** Computes ceil(log2(x))
64 */
65 int luaO_ceillog2 (unsigned int x) {
66 static const lu_byte log_2[256] = { /* log_2[i] = ceil(log2(i - 1)) */
67 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,
68 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,
69 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,
70 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,
71 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,
72 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,
73 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,
74 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
75 };
76 int l = 0;
77 x--;
78 while (x >= 256) { l += 8; x >>= 8; }
79 return l + log_2[x];
80 }
81
82
83 static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
84 lua_Integer v2) {
85 switch (op) {
86 case LUA_OPADD: return intop(+, v1, v2);
87 case LUA_OPSUB:return intop(-, v1, v2);
88 case LUA_OPMUL:return intop(*, v1, v2);
89 case LUA_OPMOD: return luaV_mod(L, v1, v2);
90 case LUA_OPIDIV: return luaV_div(L, v1, v2);
91 case LUA_OPBAND: return intop(&, v1, v2);
92 case LUA_OPBOR: return intop(|, v1, v2);
93 case LUA_OPBXOR: return intop(^, v1, v2);
94 case LUA_OPSHL: return luaV_shiftl(v1, v2);
95 case LUA_OPSHR: return luaV_shiftl(v1, -v2);
96 case LUA_OPUNM: return intop(-, 0, v1);
97 case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
98 default: lua_assert(0); return 0;
99 }
100 }
101
102
103 static lua_Number numarith (lua_State *L, int op, lua_Number v1,
104 lua_Number v2) {
105 switch (op) {
106 case LUA_OPADD: return luai_numadd(L, v1, v2);
107 case LUA_OPSUB: return luai_numsub(L, v1, v2);
108 case LUA_OPMUL: return luai_nummul(L, v1, v2);
109 case LUA_OPDIV: return luai_numdiv(L, v1, v2);
110 case LUA_OPPOW: return luai_numpow(L, v1, v2);
111 case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
112 case LUA_OPUNM: return luai_numunm(L, v1);
113 case LUA_OPMOD: {
114 lua_Number m;
115 luai_nummod(L, v1, v2, m);
116 return m;
117 }
118 default: lua_assert(0); return 0;
119 }
120 }
121
122
123 void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
124 TValue *res) {
125 switch (op) {
126 case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
127 case LUA_OPSHL: case LUA_OPSHR:
128 case LUA_OPBNOT: { /* operate only on integers */
129 lua_Integer i1; lua_Integer i2;
130 if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
131 setivalue(res, intarith(L, op, i1, i2));
132 return;
133 }
134 else break; /* go to the end */
135 }
136 case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */
137 lua_Number n1; lua_Number n2;
138 if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
139 setfltvalue(res, numarith(L, op, n1, n2));
140 return;
141 }
142 else break; /* go to the end */
143 }
144 default: { /* other operations */
145 lua_Number n1; lua_Number n2;
146 if (ttisinteger(p1) && ttisinteger(p2)) {
147 setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
148 return;
149 }
150 else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
151 setfltvalue(res, numarith(L, op, n1, n2));
152 return;
153 }
154 else break; /* go to the end */
155 }
156 }
157 /* could not perform raw operation; try metamethod */
158 lua_assert(L != NULL); /* should not fail when folding (compile time) */
159 luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
160 }
161
162
163 int luaO_hexavalue (int c) {
164 if (lisdigit(c)) return c - '0';
165 else return (ltolower(c) - 'a') + 10;
166 }
167
168
169 static int isneg (const char **s) {
170 if (**s == '-') { (*s)++; return 1; }
171 else if (**s == '+') (*s)++;
172 return 0;
173 }
174
175
176
177 /*
178 ** {==================================================================
179 ** Lua's implementation for 'lua_strx2number'
180 ** ===================================================================
181 */
182
183 #if !defined(lua_strx2number)
184
185 /* maximum number of significant digits to read (to avoid overflows
186 even with single floats) */
187 #define MAXSIGDIG 30
188
189 /*
190 ** convert an hexadecimal numeric string to a number, following
191 ** C99 specification for 'strtod'
192 */
193 static lua_Number lua_strx2number (const char *s, char **endptr) {
194 int dot = lua_getlocaledecpoint();
195 lua_Number r = 0.0; /* result (accumulator) */
196 int sigdig = 0; /* number of significant digits */
197 int nosigdig = 0; /* number of non-significant digits */
198 int e = 0; /* exponent correction */
199 int neg; /* 1 if number is negative */
200 int hasdot = 0; /* true after seen a dot */
201 *endptr = cast(char *, s); /* nothing is valid yet */
202 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
203 neg = isneg(&s); /* check signal */
204 if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */
205 return 0.0; /* invalid format (no '0x') */
206 for (s += 2; ; s++) { /* skip '0x' and read numeral */
207 if (*s == dot) {
208 if (hasdot) break; /* second dot? stop loop */
209 else hasdot = 1;
210 }
211 else if (lisxdigit(cast_uchar(*s))) {
212 if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */
213 nosigdig++;
214 else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */
215 r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
216 else e++; /* too many digits; ignore, but still count for exponent */
217 if (hasdot) e--; /* decimal digit? correct exponent */
218 }
219 else break; /* neither a dot nor a digit */
220 }
221 if (nosigdig + sigdig == 0) /* no digits? */
222 return 0.0; /* invalid format */
223 *endptr = cast(char *, s); /* valid up to here */
224 e *= 4; /* each digit multiplies/divides value by 2^4 */
225 if (*s == 'p' || *s == 'P') { /* exponent part? */
226 int exp1 = 0; /* exponent value */
227 int neg1; /* exponent signal */
228 s++; /* skip 'p' */
229 neg1 = isneg(&s); /* signal */
230 if (!lisdigit(cast_uchar(*s)))
231 return 0.0; /* invalid; must have at least one digit */
232 while (lisdigit(cast_uchar(*s))) /* read exponent */
233 exp1 = exp1 * 10 + *(s++) - '0';
234 if (neg1) exp1 = -exp1;
235 e += exp1;
236 *endptr = cast(char *, s); /* valid up to here */
237 }
238 if (neg) r = -r;
239 return l_mathop(ldexp)(r, e);
240 }
241
242 #endif
243 /* }====================================================== */
244
245
246 static const char *l_str2d (const char *s, lua_Number *result) {
247 char *endptr;
248 if (strpbrk(s, "nN")) /* reject 'inf' and 'nan' */
249 return NULL;
250 else if (strpbrk(s, "xX")) /* hex? */
251 *result = lua_strx2number(s, &endptr);
252 else
253 *result = lua_str2number(s, &endptr);
254 if (endptr == s) return NULL; /* nothing recognized */
255 while (lisspace(cast_uchar(*endptr))) endptr++;
256 return (*endptr == '\0' ? endptr : NULL); /* OK if no trailing characters */
257 }
258
259
260 static const char *l_str2int (const char *s, lua_Integer *result) {
261 lua_Unsigned a = 0;
262 int empty = 1;
263 int neg;
|
(1) Event deref_parm: |
Directly dereferencing parameter "s". |
264 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
265 neg = isneg(&s);
266 if (s[0] == '0' &&
267 (s[1] == 'x' || s[1] == 'X')) { /* hex? */
268 s += 2; /* skip '0x' */
269 for (; lisxdigit(cast_uchar(*s)); s++) {
270 a = a * 16 + luaO_hexavalue(*s);
271 empty = 0;
272 }
273 }
274 else { /* decimal */
275 for (; lisdigit(cast_uchar(*s)); s++) {
276 a = a * 10 + *s - '0';
277 empty = 0;
278 }
279 }
280 while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */
281 if (empty || *s != '\0') return NULL; /* something wrong in the numeral */
282 else {
283 *result = l_castU2S((neg) ? 0u - a : a);
284 return s;
285 }
286 }
287
288
289 size_t luaO_str2num (const char *s, TValue *o) {
290 lua_Integer i; lua_Number n;
291 const char *e;
|
(1) Event deref_parm_in_call: |
Function "l_str2int" dereferences "s". [details] |
292 if ((e = l_str2int(s, &i)) != NULL) { /* try as an integer */
293 setivalue(o, i);
294 }
295 else if ((e = l_str2d(s, &n)) != NULL) { /* else try as a float */
296 setfltvalue(o, n);
297 }
298 else
299 return 0; /* conversion failed */
300 return (e - s) + 1; /* success; return string size */
301 }
302
303
304 int luaO_utf8esc (char *buff, unsigned long x) {
305 int n = 1; /* number of bytes put in buffer (backwards) */
306 lua_assert(x <= 0x10FFFF);
307 if (x < 0x80) /* ascii? */
308 buff[UTF8BUFFSZ - 1] = cast(char, x);
309 else { /* need continuation bytes */
310 unsigned int mfb = 0x3f; /* maximum that fits in first byte */
311 do { /* add continuation bytes */
312 buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
313 x >>= 6; /* remove added bits */
314 mfb >>= 1; /* now there is one less bit available in first byte */
315 } while (x > mfb); /* still needs continuation byte? */
316 buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x); /* add first byte */
317 }
318 return n;
319 }
320
321
322 /* maximum length of the conversion of a number to a string */
323 #define MAXNUMBER2STR 50
324
325
326 /*
327 ** Convert a number object to a string
328 */
329 void luaO_tostring (lua_State *L, StkId obj) {
330 char buff[MAXNUMBER2STR];
331 size_t len;
332 lua_assert(ttisnumber(obj));
333 if (ttisinteger(obj))
334 len = lua_integer2str(buff, sizeof(buff), ivalue(obj));
335 else {
336 len = lua_number2str(buff, sizeof(buff), fltvalue(obj));
337 #if !defined(LUA_COMPAT_FLOATSTRING)
338 if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */
339 buff[len++] = lua_getlocaledecpoint();
340 buff[len++] = '0'; /* adds '.0' to result */
341 }
342 #endif
343 }
344 setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
345 }
346
347
348 static void pushstr (lua_State *L, const char *str, size_t l) {
349 setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
350 luaD_inctop(L);
351 }
352
353
354 /* this function handles only '%d', '%c', '%f', '%p', and '%s'
355 conventional formats, plus Lua-specific '%I' and '%U' */
356 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
357 int n = 0;
358 for (;;) {
359 const char *e = strchr(fmt, '%');
360 if (e == NULL) break;
361 pushstr(L, fmt, e - fmt);
362 switch (*(e+1)) {
363 case 's': {
364 const char *s = va_arg(argp, char *);
365 if (s == NULL) s = "(null)";
366 pushstr(L, s, strlen(s));
367 break;
368 }
369 case 'c': {
370 char buff = cast(char, va_arg(argp, int));
371 if (lisprint(cast_uchar(buff)))
372 pushstr(L, &buff, 1);
373 else /* non-printable character; print its code */
374 luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
375 break;
376 }
377 case 'd': {
378 setivalue(L->top, va_arg(argp, int));
379 goto top2str;
380 }
381 case 'I': {
382 setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt)));
383 goto top2str;
384 }
385 case 'f': {
386 setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
387 top2str:
388 luaD_inctop(L);
389 luaO_tostring(L, L->top - 1);
390 break;
391 }
392 case 'p': {
393 char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
394 int l = l_sprintf(buff, sizeof(buff), "%p", va_arg(argp, void *));
395 pushstr(L, buff, l);
396 break;
397 }
398 case 'U': {
399 char buff[UTF8BUFFSZ];
400 int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
401 pushstr(L, buff + UTF8BUFFSZ - l, l);
402 break;
403 }
404 case '%': {
405 pushstr(L, "%", 1);
406 break;
407 }
408 default: {
409 luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
410 *(e + 1));
411 }
412 }
413 n += 2;
414 fmt = e+2;
415 }
416 luaD_checkstack(L, 1);
417 pushstr(L, fmt, strlen(fmt));
418 if (n > 0) luaV_concat(L, n + 1);
419 return svalue(L->top - 1);
420 }
421
422
423 const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
424 const char *msg;
425 va_list argp;
426 va_start(argp, fmt);
427 msg = luaO_pushvfstring(L, fmt, argp);
428 va_end(argp);
429 return msg;
430 }
431
432
433 /* number of chars of a literal string without the ending \0 */
434 #define LL(x) (sizeof(x)/sizeof(char) - 1)
435
436 #define RETS "..."
437 #define PRE "[string \""
438 #define POS "\"]"
439
440 #define addstr(a,b,l) ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
441
442 void luaO_chunkid (char *out, const char *source, size_t bufflen) {
443 size_t l = strlen(source);
444 if (*source == '=') { /* 'literal' source */
445 if (l <= bufflen) /* small enough? */
446 memcpy(out, source + 1, l * sizeof(char));
447 else { /* truncate it */
448 addstr(out, source + 1, bufflen - 1);
449 *out = '\0';
450 }
451 }
452 else if (*source == '@') { /* file name */
453 if (l <= bufflen) /* small enough? */
454 memcpy(out, source + 1, l * sizeof(char));
455 else { /* add '...' before rest of name */
456 addstr(out, RETS, LL(RETS));
457 bufflen -= LL(RETS);
458 memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
459 }
460 }
461 else { /* string; format as [string "source"] */
462 const char *nl = strchr(source, '\n'); /* find first new line (if any) */
463 addstr(out, PRE, LL(PRE)); /* add prefix */
464 bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */
465 if (l < bufflen && nl == NULL) { /* small one-line source? */
466 addstr(out, source, l); /* keep it */
467 }
468 else {
469 if (nl != NULL) l = nl - source; /* stop at first newline */
470 if (l > bufflen) l = bufflen;
471 addstr(out, source, l);
472 addstr(out, RETS, LL(RETS));
473 }
474 memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
475 }
476 }
477
478