1/*
2** $Id: lobject.c,v 2.58.1.1 2013/04/12 18:48:47 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 <sys/lua/lua.h>
11
12#include "lctype.h"
13#include "ldebug.h"
14#include "ldo.h"
15#include "lmem.h"
16#include "lobject.h"
17#include "lstate.h"
18#include "lstring.h"
19#include "lvm.h"
20
21
22
23LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
24
25
26/*
27** converts an integer to a "floating point byte", represented as
28** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
29** eeeee != 0 and (xxx) otherwise.
30*/
31int luaO_int2fb (unsigned int x) {
32  int e = 0;  /* exponent */
33  if (x < 8) return x;
34  while (x >= 0x10) {
35    x = (x+1) >> 1;
36    e++;
37  }
38  return ((e+1) << 3) | (cast_int(x) - 8);
39}
40
41
42/* converts back */
43int luaO_fb2int (int x) {
44  int e = (x >> 3) & 0x1f;
45  if (e == 0) return x;
46  else return ((x & 7) + 8) << (e - 1);
47}
48
49
50int luaO_ceillog2 (unsigned int x) {
51  static const lu_byte log_2[256] = {
52    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,
53    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,
54    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,
55    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,
56    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,
57    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,
58    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,
59    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
60  };
61  int l = 0;
62  x--;
63  while (x >= 256) { l += 8; x >>= 8; }
64  return l + log_2[x];
65}
66
67
68lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2) {
69  switch (op) {
70    case LUA_OPADD: return luai_numadd(NULL, v1, v2);
71    case LUA_OPSUB: return luai_numsub(NULL, v1, v2);
72    case LUA_OPMUL: return luai_nummul(NULL, v1, v2);
73    case LUA_OPDIV: return luai_numdiv(NULL, v1, v2);
74    case LUA_OPMOD: return luai_nummod(NULL, v1, v2);
75    case LUA_OPPOW: return luai_numpow(NULL, v1, v2);
76    case LUA_OPUNM: return luai_numunm(NULL, v1);
77    default: lua_assert(0); return 0;
78  }
79}
80
81
82int luaO_hexavalue (int c) {
83  if (lisdigit(c)) return c - '0';
84  else return ltolower(c) - 'a' + 10;
85}
86
87
88#if !defined(lua_strx2number)
89
90
91
92static int isneg (const char **s) {
93  if (**s == '-') { (*s)++; return 1; }
94  else if (**s == '+') (*s)++;
95  return 0;
96}
97
98
99static lua_Number readhexa (const char **s, lua_Number r, int *count) {
100  for (; lisxdigit(cast_uchar(**s)); (*s)++) {  /* read integer part */
101    r = (r * cast_num(16.0)) + cast_num(luaO_hexavalue(cast_uchar(**s)));
102    (*count)++;
103  }
104  return r;
105}
106
107
108/*
109** convert an hexadecimal numeric string to a number, following
110** C99 specification for 'strtod'
111*/
112static lua_Number lua_strx2number (const char *s, char **endptr) {
113  lua_Number r = 0.0;
114  int e = 0, i = 0;
115  int neg = 0;  /* 1 if number is negative */
116  *endptr = cast(char *, s);  /* nothing is valid yet */
117  while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
118  neg = isneg(&s);  /* check signal */
119  if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
120    return 0.0;  /* invalid format (no '0x') */
121  s += 2;  /* skip '0x' */
122  r = readhexa(&s, r, &i);  /* read integer part */
123  if (*s == '.') {
124    s++;  /* skip dot */
125    r = readhexa(&s, r, &e);  /* read fractional part */
126  }
127  if (i == 0 && e == 0)
128    return 0.0;  /* invalid format (no digit) */
129  e *= -4;  /* each fractional digit divides value by 2^-4 */
130  *endptr = cast(char *, s);  /* valid up to here */
131  if (*s == 'p' || *s == 'P') {  /* exponent part? */
132    int exp1 = 0;
133    int neg1;
134    s++;  /* skip 'p' */
135    neg1 = isneg(&s);  /* signal */
136    if (!lisdigit(cast_uchar(*s)))
137      goto ret;  /* must have at least one digit */
138    while (lisdigit(cast_uchar(*s)))  /* read exponent */
139      exp1 = exp1 * 10 + *(s++) - '0';
140    if (neg1) exp1 = -exp1;
141    e += exp1;
142  }
143  *endptr = cast(char *, s);  /* valid up to here */
144 ret:
145  if (neg) r = -r;
146  return ((e >= 0) ? (r * (1ULL << e)) : (r / (1ULL << -e)));
147}
148
149#endif
150
151
152int luaO_str2d (const char *s, size_t len, lua_Number *result) {
153  char *endptr;
154  if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */
155    return 0;
156  else if (strpbrk(s, "xX"))  /* hexa? */
157    *result = lua_strx2number(s, &endptr);
158  else
159    *result = lua_str2number(s, &endptr);
160  if (endptr == s) return 0;  /* nothing recognized */
161  while (lisspace(cast_uchar(*endptr))) endptr++;
162  return (endptr == s + len);  /* OK if no trailing characters */
163}
164
165
166
167static void pushstr (lua_State *L, const char *str, size_t l) {
168  setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
169}
170
171
172/* this function handles only `%d', `%c', %f, %p, and `%s' formats */
173const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
174  int n = 0;
175  for (;;) {
176    const char *e = strchr(fmt, '%');
177    if (e == NULL) break;
178    luaD_checkstack(L, 2);  /* fmt + item */
179    pushstr(L, fmt, e - fmt);
180    switch (*(e+1)) {
181      case 's': {
182        const char *s = va_arg(argp, char *);
183        if (s == NULL) s = "(null)";
184        pushstr(L, s, strlen(s));
185        break;
186      }
187      case 'c': {
188        char buff;
189        buff = cast(char, va_arg(argp, int));
190        pushstr(L, &buff, 1);
191        break;
192      }
193      case 'd': {
194        setnvalue(L->top++, cast_num(va_arg(argp, int)));
195        break;
196      }
197      case 'f': {
198        setnvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
199        break;
200      }
201      case 'p': {
202        char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
203        int l = lcompat_sprintf(buff, sizeof(buff), "%p", va_arg(argp, void *));
204        pushstr(L, buff, l);
205        break;
206      }
207      case '%': {
208        pushstr(L, "%", 1);
209        break;
210      }
211      default: {
212        luaG_runerror(L,
213            "invalid option " LUA_QL("%%%c") " to " LUA_QL("lua_pushfstring"),
214            *(e + 1));
215      }
216    }
217    n += 2;
218    fmt = e+2;
219  }
220  luaD_checkstack(L, 1);
221  pushstr(L, fmt, strlen(fmt));
222  if (n > 0) luaV_concat(L, n + 1);
223  return svalue(L->top - 1);
224}
225
226
227const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
228  const char *msg;
229  va_list argp;
230  va_start(argp, fmt);
231  msg = luaO_pushvfstring(L, fmt, argp);
232  va_end(argp);
233  return msg;
234}
235
236
237/* number of chars of a literal string without the ending \0 */
238#define LL(x)	(sizeof(x)/sizeof(char) - 1)
239
240#define RETS	"..."
241#define PRE	"[string \""
242#define POS	"\"]"
243
244#define addstr(a,b,l)	( memcpy(a,b,(l) * sizeof(char)), a += (l) )
245
246void luaO_chunkid (char *out, const char *source, size_t bufflen) {
247  size_t l = strlen(source);
248  if (*source == '=') {  /* 'literal' source */
249    if (l <= bufflen)  /* small enough? */
250      memcpy(out, source + 1, l * sizeof(char));
251    else {  /* truncate it */
252      addstr(out, source + 1, bufflen - 1);
253      *out = '\0';
254    }
255  }
256  else if (*source == '@') {  /* file name */
257    if (l <= bufflen)  /* small enough? */
258      memcpy(out, source + 1, l * sizeof(char));
259    else {  /* add '...' before rest of name */
260      addstr(out, RETS, LL(RETS));
261      bufflen -= LL(RETS);
262      memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
263    }
264  }
265  else {  /* string; format as [string "source"] */
266    const char *nl = strchr(source, '\n');  /* find first new line (if any) */
267    addstr(out, PRE, LL(PRE));  /* add prefix */
268    bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
269    if (l < bufflen && nl == NULL) {  /* small one-line source? */
270      addstr(out, source, l);  /* keep it */
271    }
272    else {
273      if (nl != NULL) l = nl - source;  /* stop at first newline */
274      if (l > bufflen) l = bufflen;
275      addstr(out, source, l);
276      addstr(out, RETS, LL(RETS));
277    }
278    memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
279  }
280}
281