1 /* $NetBSD: lobject.c,v 1.5 2015/10/08 13:21:00 mbalmer Exp $ */
2
3 /*
4 ** Id: lobject.c,v 2.104 2015/04/11 18:30:08 roberto Exp
5 ** Some generic functions over Lua objects
6 ** See Copyright Notice in lua.h
7 */
8
9 #define lobject_c
10 #define LUA_CORE
11
12 #include "lprefix.h"
13
14
15 #ifndef _KERNEL
16 #include <locale.h>
17 #include <math.h>
18 #include <stdarg.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #endif
23
24 #include "lua.h"
25
26 #include "lctype.h"
27 #include "ldebug.h"
28 #include "ldo.h"
29 #include "lmem.h"
30 #include "lobject.h"
31 #include "lstate.h"
32 #include "lstring.h"
33 #include "lvm.h"
34
35
36
37 LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
38
39
40 /*
41 ** converts an integer to a "floating point byte", represented as
42 ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
43 ** eeeee != 0 and (xxx) otherwise.
44 */
luaO_int2fb(unsigned int x)45 int luaO_int2fb (unsigned int x) {
46 int e = 0; /* exponent */
47 if (x < 8) return x;
48 while (x >= (8 << 4)) { /* coarse steps */
49 x = (x + 0xf) >> 4; /* x = ceil(x / 16) */
50 e += 4;
51 }
52 while (x >= (8 << 1)) { /* fine steps */
53 x = (x + 1) >> 1; /* x = ceil(x / 2) */
54 e++;
55 }
56 return ((e+1) << 3) | (cast_int(x) - 8);
57 }
58
59
60 /* converts back */
luaO_fb2int(int x)61 int luaO_fb2int (int x) {
62 int e = (x >> 3) & 0x1f;
63 if (e == 0) return x;
64 else return ((x & 7) + 8) << (e - 1);
65 }
66
67
68 /*
69 ** Computes ceil(log2(x))
70 */
luaO_ceillog2(unsigned int x)71 int luaO_ceillog2 (unsigned int x) {
72 static const lu_byte log_2[256] = { /* log_2[i] = ceil(log2(i - 1)) */
73 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,
74 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,
75 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,
76 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,
77 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,
78 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,
79 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,
80 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
81 };
82 int l = 0;
83 x--;
84 while (x >= 256) { l += 8; x >>= 8; }
85 return l + log_2[x];
86 }
87
88
intarith(lua_State * L,int op,lua_Integer v1,lua_Integer v2)89 static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
90 lua_Integer v2) {
91 switch (op) {
92 case LUA_OPADD: return intop(+, v1, v2);
93 case LUA_OPSUB:return intop(-, v1, v2);
94 case LUA_OPMUL:return intop(*, v1, v2);
95 case LUA_OPMOD: return luaV_mod(L, v1, v2);
96 case LUA_OPIDIV: return luaV_div(L, v1, v2);
97 case LUA_OPBAND: return intop(&, v1, v2);
98 case LUA_OPBOR: return intop(|, v1, v2);
99 case LUA_OPBXOR: return intop(^, v1, v2);
100 case LUA_OPSHL: return luaV_shiftl(v1, v2);
101 case LUA_OPSHR: return luaV_shiftl(v1, -v2);
102 case LUA_OPUNM: return intop(-, 0, v1);
103 case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
104 default: lua_assert(0); return 0;
105 }
106 }
107
108
109 #ifndef _KERNEL
numarith(lua_State * L,int op,lua_Number v1,lua_Number v2)110 static lua_Number numarith (lua_State *L, int op, lua_Number v1,
111 lua_Number v2) {
112 switch (op) {
113 case LUA_OPADD: return luai_numadd(L, v1, v2);
114 case LUA_OPSUB: return luai_numsub(L, v1, v2);
115 case LUA_OPMUL: return luai_nummul(L, v1, v2);
116 case LUA_OPDIV: return luai_numdiv(L, v1, v2);
117 case LUA_OPPOW: return luai_numpow(L, v1, v2);
118 case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
119 case LUA_OPUNM: return luai_numunm(L, v1);
120 case LUA_OPMOD: {
121 lua_Number m;
122 luai_nummod(L, v1, v2, m);
123 return m;
124 }
125 default: lua_assert(0); return 0;
126 }
127 }
128 #endif
129
130
luaO_arith(lua_State * L,int op,const TValue * p1,const TValue * p2,TValue * res)131 void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
132 TValue *res) {
133 switch (op) {
134 case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
135 case LUA_OPSHL: case LUA_OPSHR:
136 case LUA_OPBNOT: { /* operate only on integers */
137 lua_Integer i1; lua_Integer i2;
138 if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
139 setivalue(res, intarith(L, op, i1, i2));
140 return;
141 }
142 else break; /* go to the end */
143 }
144 #ifndef _KERNEL
145 case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */
146 lua_Number n1; lua_Number n2;
147 if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
148 setfltvalue(res, numarith(L, op, n1, n2));
149 return;
150 }
151 else break; /* go to the end */
152 }
153 #endif
154 default: { /* other operations */
155 #ifndef _KERNEL
156 lua_Number n1; lua_Number n2;
157 if (ttisinteger(p1) && ttisinteger(p2)) {
158 setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
159 return;
160 }
161 else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
162 setfltvalue(res, numarith(L, op, n1, n2));
163 return;
164 }
165 #else /* _KERNEL */
166 lua_Integer i1; lua_Integer i2;
167 if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
168 setivalue(res, intarith(L, op, i1, i2));
169 return;
170 }
171 #endif
172 else break; /* go to the end */
173 }
174 }
175 /* could not perform raw operation; try metamethod */
176 lua_assert(L != NULL); /* should not fail when folding (compile time) */
177 luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
178 }
179
180
luaO_hexavalue(int c)181 int luaO_hexavalue (int c) {
182 if (lisdigit(c)) return c - '0';
183 else return (ltolower(c) - 'a') + 10;
184 }
185
186
isneg(const char ** s)187 static int isneg (const char **s) {
188 if (**s == '-') { (*s)++; return 1; }
189 else if (**s == '+') (*s)++;
190 return 0;
191 }
192
193
194
195 #ifndef _KERNEL
196 /*
197 ** {==================================================================
198 ** Lua's implementation for 'lua_strx2number'
199 ** ===================================================================
200 */
201
202 #if !defined(lua_strx2number)
203
204 /* maximum number of significant digits to read (to avoid overflows
205 even with single floats) */
206 #define MAXSIGDIG 30
207
208 /*
209 ** convert an hexadecimal numeric string to a number, following
210 ** C99 specification for 'strtod'
211 */
lua_strx2number(const char * s,char ** endptr)212 static lua_Number lua_strx2number (const char *s, char **endptr) {
213 int dot = lua_getlocaledecpoint();
214 lua_Number r = 0.0; /* result (accumulator) */
215 int sigdig = 0; /* number of significant digits */
216 int nosigdig = 0; /* number of non-significant digits */
217 int e = 0; /* exponent correction */
218 int neg; /* 1 if number is negative */
219 int hasdot = 0; /* true after seen a dot */
220 *endptr = cast(char *, s); /* nothing is valid yet */
221 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
222 neg = isneg(&s); /* check signal */
223 if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */
224 return 0.0; /* invalid format (no '0x') */
225 for (s += 2; ; s++) { /* skip '0x' and read numeral */
226 if (*s == dot) {
227 if (hasdot) break; /* second dot? stop loop */
228 else hasdot = 1;
229 }
230 else if (lisxdigit(cast_uchar(*s))) {
231 if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */
232 nosigdig++;
233 else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */
234 r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
235 else e++; /* too many digits; ignore, but still count for exponent */
236 if (hasdot) e--; /* decimal digit? correct exponent */
237 }
238 else break; /* neither a dot nor a digit */
239 }
240 if (nosigdig + sigdig == 0) /* no digits? */
241 return 0.0; /* invalid format */
242 *endptr = cast(char *, s); /* valid up to here */
243 e *= 4; /* each digit multiplies/divides value by 2^4 */
244 if (*s == 'p' || *s == 'P') { /* exponent part? */
245 int exp1 = 0; /* exponent value */
246 int neg1; /* exponent signal */
247 s++; /* skip 'p' */
248 neg1 = isneg(&s); /* signal */
249 if (!lisdigit(cast_uchar(*s)))
250 return 0.0; /* invalid; must have at least one digit */
251 while (lisdigit(cast_uchar(*s))) /* read exponent */
252 exp1 = exp1 * 10 + *(s++) - '0';
253 if (neg1) exp1 = -exp1;
254 e += exp1;
255 *endptr = cast(char *, s); /* valid up to here */
256 }
257 if (neg) r = -r;
258 return l_mathop(ldexp)(r, e);
259 }
260
261 #endif
262 /* }====================================================== */
263
264
l_str2d(const char * s,lua_Number * result)265 static const char *l_str2d (const char *s, lua_Number *result) {
266 char *endptr;
267 if (strpbrk(s, "nN")) /* reject 'inf' and 'nan' */
268 return NULL;
269 else if (strpbrk(s, "xX")) /* hex? */
270 *result = lua_strx2number(s, &endptr);
271 else
272 *result = lua_str2number(s, &endptr);
273 if (endptr == s) return NULL; /* nothing recognized */
274 while (lisspace(cast_uchar(*endptr))) endptr++;
275 return (*endptr == '\0' ? endptr : NULL); /* OK if no trailing characters */
276 }
277 #endif /* _KERNEL */
278
279
l_str2int(const char * s,lua_Integer * result)280 static const char *l_str2int (const char *s, lua_Integer *result) {
281 lua_Unsigned a = 0;
282 int empty = 1;
283 int neg;
284 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
285 neg = isneg(&s);
286 if (s[0] == '0' &&
287 (s[1] == 'x' || s[1] == 'X')) { /* hex? */
288 s += 2; /* skip '0x' */
289 for (; lisxdigit(cast_uchar(*s)); s++) {
290 a = a * 16 + luaO_hexavalue(*s);
291 empty = 0;
292 }
293 }
294 else { /* decimal */
295 for (; lisdigit(cast_uchar(*s)); s++) {
296 a = a * 10 + *s - '0';
297 empty = 0;
298 }
299 }
300 while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */
301 if (empty || *s != '\0') return NULL; /* something wrong in the numeral */
302 else {
303 *result = l_castU2S((neg) ? 0u - a : a);
304 return s;
305 }
306 }
307
308
luaO_str2num(const char * s,TValue * o)309 size_t luaO_str2num (const char *s, TValue *o) {
310 #ifndef _KERNEL
311 lua_Integer i; lua_Number n;
312 #else /* _KERNEL */
313 lua_Integer i;
314 #endif
315 const char *e;
316 if ((e = l_str2int(s, &i)) != NULL) { /* try as an integer */
317 setivalue(o, i);
318 }
319 #ifndef _KERNEL
320 else if ((e = l_str2d(s, &n)) != NULL) { /* else try as a float */
321 setfltvalue(o, n);
322 }
323 #endif
324 else
325 return 0; /* conversion failed */
326 return (e - s) + 1; /* success; return string size */
327 }
328
329
luaO_utf8esc(char * buff,unsigned long x)330 int luaO_utf8esc (char *buff, unsigned long x) {
331 int n = 1; /* number of bytes put in buffer (backwards) */
332 lua_assert(x <= 0x10FFFF);
333 if (x < 0x80) /* ascii? */
334 buff[UTF8BUFFSZ - 1] = cast(char, x);
335 else { /* need continuation bytes */
336 unsigned int mfb = 0x3f; /* maximum that fits in first byte */
337 do { /* add continuation bytes */
338 buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
339 x >>= 6; /* remove added bits */
340 mfb >>= 1; /* now there is one less bit available in first byte */
341 } while (x > mfb); /* still needs continuation byte? */
342 buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x); /* add first byte */
343 }
344 return n;
345 }
346
347
348 /* maximum length of the conversion of a number to a string */
349 #define MAXNUMBER2STR 50
350
351
352 /*
353 ** Convert a number object to a string
354 */
luaO_tostring(lua_State * L,StkId obj)355 void luaO_tostring (lua_State *L, StkId obj) {
356 char buff[MAXNUMBER2STR];
357 size_t len;
358 lua_assert(ttisnumber(obj));
359 #ifndef _KERNEL
360 if (ttisinteger(obj))
361 len = lua_integer2str(buff, ivalue(obj));
362 else {
363 len = lua_number2str(buff, fltvalue(obj));
364 #if !defined(LUA_COMPAT_FLOATSTRING)
365 if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */
366 buff[len++] = lua_getlocaledecpoint();
367 buff[len++] = '0'; /* adds '.0' to result */
368 }
369 #endif
370 }
371 #else /* _KERNEL */
372 lua_assert(ttisinteger(obj));
373 len = lua_integer2str(buff, ivalue(obj));
374 #endif
375 setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
376 }
377
378
pushstr(lua_State * L,const char * str,size_t l)379 static void pushstr (lua_State *L, const char *str, size_t l) {
380 setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
381 }
382
383
384 /* this function handles only '%d', '%c', '%f', '%p', and '%s'
385 conventional formats, plus Lua-specific '%I' and '%U' */
luaO_pushvfstring(lua_State * L,const char * fmt,va_list argp)386 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
387 int n = 0;
388 for (;;) {
389 const char *e = strchr(fmt, '%');
390 if (e == NULL) break;
391 luaD_checkstack(L, 2); /* fmt + item */
392 pushstr(L, fmt, e - fmt);
393 switch (*(e+1)) {
394 case 's': {
395 const char *s = va_arg(argp, char *);
396 if (s == NULL) s = "(null)";
397 pushstr(L, s, strlen(s));
398 break;
399 }
400 case 'c': {
401 char buff = cast(char, va_arg(argp, int));
402 if (lisprint(cast_uchar(buff)))
403 pushstr(L, &buff, 1);
404 else /* non-printable character; print its code */
405 luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
406 break;
407 }
408 case 'd': {
409 setivalue(L->top++, va_arg(argp, int));
410 luaO_tostring(L, L->top - 1);
411 break;
412 }
413 case 'I': {
414 setivalue(L->top++, cast(lua_Integer, va_arg(argp, l_uacInt)));
415 luaO_tostring(L, L->top - 1);
416 break;
417 }
418 #ifndef _KERNEL
419 case 'f': {
420 setfltvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
421 luaO_tostring(L, L->top - 1);
422 break;
423 }
424 #endif
425 case 'p': {
426 char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
427 int l = sprintf(buff, "%p", va_arg(argp, void *));
428 pushstr(L, buff, l);
429 break;
430 }
431 case 'U': {
432 char buff[UTF8BUFFSZ];
433 int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
434 pushstr(L, buff + UTF8BUFFSZ - l, l);
435 break;
436 }
437 case '%': {
438 pushstr(L, "%", 1);
439 break;
440 }
441 default: {
442 luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
443 *(e + 1));
444 }
445 }
446 n += 2;
447 fmt = e+2;
448 }
449 luaD_checkstack(L, 1);
450 pushstr(L, fmt, strlen(fmt));
451 if (n > 0) luaV_concat(L, n + 1);
452 return svalue(L->top - 1);
453 }
454
455
luaO_pushfstring(lua_State * L,const char * fmt,...)456 const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
457 const char *msg;
458 va_list argp;
459 va_start(argp, fmt);
460 msg = luaO_pushvfstring(L, fmt, argp);
461 va_end(argp);
462 return msg;
463 }
464
465
466 /* number of chars of a literal string without the ending \0 */
467 #define LL(x) (sizeof(x)/sizeof(char) - 1)
468
469 #define RETS "..."
470 #define PRE "[string \""
471 #define POS "\"]"
472
473 #define addstr(a,b,l) ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
474
luaO_chunkid(char * out,const char * source,size_t bufflen)475 void luaO_chunkid (char *out, const char *source, size_t bufflen) {
476 size_t l = strlen(source);
477 if (*source == '=') { /* 'literal' source */
478 if (l <= bufflen) /* small enough? */
479 memcpy(out, source + 1, l * sizeof(char));
480 else { /* truncate it */
481 addstr(out, source + 1, bufflen - 1);
482 *out = '\0';
483 }
484 }
485 else if (*source == '@') { /* file name */
486 if (l <= bufflen) /* small enough? */
487 memcpy(out, source + 1, l * sizeof(char));
488 else { /* add '...' before rest of name */
489 addstr(out, RETS, LL(RETS));
490 bufflen -= LL(RETS);
491 memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
492 }
493 }
494 else { /* string; format as [string "source"] */
495 const char *nl = strchr(source, '\n'); /* find first new line (if any) */
496 addstr(out, PRE, LL(PRE)); /* add prefix */
497 bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */
498 if (l < bufflen && nl == NULL) { /* small one-line source? */
499 addstr(out, source, l); /* keep it */
500 }
501 else {
502 if (nl != NULL) l = nl - source; /* stop at first newline */
503 if (l > bufflen) l = bufflen;
504 addstr(out, source, l);
505 addstr(out, RETS, LL(RETS));
506 }
507 memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
508 }
509 }
510
511