1/*
2** $Id: lobject.c,v 2.58 2013/02/20 14:08:56 roberto Exp $
3** Some generic functions over Lua objects
4** See Copyright Notice in lua.h
5*/
6
7#include <stdarg.h>
8#include <stdio.h>
9#include <stdlib.h>
10#include <string.h>
11
12#define lobject_c
13#define LUA_CORE
14
15#include "lua.h"
16
17#include "lctype.h"
18#include "ldebug.h"
19#include "ldo.h"
20#include "lmem.h"
21#include "lobject.h"
22#include "lstate.h"
23#include "lstring.h"
24#include "lvm.h"
25
26
27
28LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
29
30
31/*
32** converts an integer to a "floating point byte", represented as
33** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
34** eeeee != 0 and (xxx) otherwise.
35*/
36int luaO_int2fb (unsigned int x) {
37  int e = 0;  /* exponent */
38  if (x < 8) return x;
39  while (x >= 0x10) {
40    x = (x+1) >> 1;
41    e++;
42  }
43  return ((e+1) << 3) | (cast_int(x) - 8);
44}
45
46
47/* converts back */
48int luaO_fb2int (int x) {
49  int e = (x >> 3) & 0x1f;
50  if (e == 0) return x;
51  else return ((x & 7) + 8) << (e - 1);
52}
53
54
55int luaO_ceillog2 (unsigned int x) {
56  static const lu_byte log_2[256] = {
57    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,
58    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,
59    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,
60    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,
61    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,
62    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,
63    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,
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  };
66  int l = 0;
67  x--;
68  while (x >= 256) { l += 8; x >>= 8; }
69  return l + log_2[x];
70}
71
72
73lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2) {
74  switch (op) {
75    case LUA_OPADD: return luai_numadd(NULL, v1, v2);
76    case LUA_OPSUB: return luai_numsub(NULL, v1, v2);
77    case LUA_OPMUL: return luai_nummul(NULL, v1, v2);
78    case LUA_OPDIV: return luai_numdiv(NULL, v1, v2);
79    case LUA_OPMOD: return luai_nummod(NULL, v1, v2);
80    case LUA_OPPOW: return luai_numpow(NULL, v1, v2);
81    case LUA_OPUNM: return luai_numunm(NULL, v1);
82    default: lua_assert(0); return 0;
83  }
84}
85
86
87int luaO_hexavalue (int c) {
88  if (lisdigit(c)) return c - '0';
89  else return ltolower(c) - 'a' + 10;
90}
91
92
93#if !defined(lua_strx2number)
94
95#include <math.h>
96
97
98static int isneg (const char **s) {
99  if (**s == '-') { (*s)++; return 1; }
100  else if (**s == '+') (*s)++;
101  return 0;
102}
103
104
105static lua_Number readhexa (const char **s, lua_Number r, int *count) {
106  for (; lisxdigit(cast_uchar(**s)); (*s)++) {  /* read integer part */
107    r = (r * cast_num(16.0)) + cast_num(luaO_hexavalue(cast_uchar(**s)));
108    (*count)++;
109  }
110  return r;
111}
112
113
114/*
115** convert an hexadecimal numeric string to a number, following
116** C99 specification for 'strtod'
117*/
118static lua_Number lua_strx2number (const char *s, char **endptr) {
119  lua_Number r = 0.0;
120  int e = 0, i = 0;
121  int neg = 0;  /* 1 if number is negative */
122  *endptr = cast(char *, s);  /* nothing is valid yet */
123  while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
124  neg = isneg(&s);  /* check signal */
125  if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
126    return 0.0;  /* invalid format (no '0x') */
127  s += 2;  /* skip '0x' */
128  r = readhexa(&s, r, &i);  /* read integer part */
129  if (*s == '.') {
130    s++;  /* skip dot */
131    r = readhexa(&s, r, &e);  /* read fractional part */
132  }
133  if (i == 0 && e == 0)
134    return 0.0;  /* invalid format (no digit) */
135  e *= -4;  /* each fractional digit divides value by 2^-4 */
136  *endptr = cast(char *, s);  /* valid up to here */
137  if (*s == 'p' || *s == 'P') {  /* exponent part? */
138    int exp1 = 0;
139    int neg1;
140    s++;  /* skip 'p' */
141    neg1 = isneg(&s);  /* signal */
142    if (!lisdigit(cast_uchar(*s)))
143      goto ret;  /* must have at least one digit */
144    while (lisdigit(cast_uchar(*s)))  /* read exponent */
145      exp1 = exp1 * 10 + *(s++) - '0';
146    if (neg1) exp1 = -exp1;
147    e += exp1;
148  }
149  *endptr = cast(char *, s);  /* valid up to here */
150 ret:
151  if (neg) r = -r;
152  return l_mathop(ldexp)(r, e);
153}
154
155#endif
156
157
158int luaO_str2d (const char *s, size_t len, lua_Number *result) {
159  char *endptr;
160  if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */
161    return 0;
162  else if (strpbrk(s, "xX"))  /* hexa? */
163    *result = lua_strx2number(s, &endptr);
164  else
165    *result = lua_str2number(s, &endptr);
166  if (endptr == s) return 0;  /* nothing recognized */
167  while (lisspace(cast_uchar(*endptr))) endptr++;
168  return (endptr == s + len);  /* OK if no trailing characters */
169}
170
171
172
173static void pushstr (lua_State *L, const char *str, size_t l) {
174  setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
175}
176
177
178/* this function handles only `%d', `%c', %f, %p, and `%s' formats */
179const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
180  int n = 0;
181  for (;;) {
182    const char *e = strchr(fmt, '%');
183    if (e == NULL) break;
184    luaD_checkstack(L, 2);  /* fmt + item */
185    pushstr(L, fmt, e - fmt);
186    switch (*(e+1)) {
187      case 's': {
188        const char *s = va_arg(argp, char *);
189        if (s == NULL) s = "(null)";
190        pushstr(L, s, strlen(s));
191        break;
192      }
193      case 'c': {
194        char buff;
195        buff = cast(char, va_arg(argp, int));
196        pushstr(L, &buff, 1);
197        break;
198      }
199      case 'd': {
200        setnvalue(L->top++, cast_num(va_arg(argp, int)));
201        break;
202      }
203      case 'f': {
204        setnvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
205        break;
206      }
207      case 'p': {
208        char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
209        int l = sprintf(buff, "%p", va_arg(argp, void *));
210        pushstr(L, buff, l);
211        break;
212      }
213      case '%': {
214        pushstr(L, "%", 1);
215        break;
216      }
217      default: {
218        luaG_runerror(L,
219            "invalid option " LUA_QL("%%%c") " to " LUA_QL("lua_pushfstring"),
220            *(e + 1));
221      }
222    }
223    n += 2;
224    fmt = e+2;
225  }
226  luaD_checkstack(L, 1);
227  pushstr(L, fmt, strlen(fmt));
228  if (n > 0) luaV_concat(L, n + 1);
229  return svalue(L->top - 1);
230}
231
232
233const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
234  const char *msg;
235  va_list argp;
236  va_start(argp, fmt);
237  msg = luaO_pushvfstring(L, fmt, argp);
238  va_end(argp);
239  return msg;
240}
241
242
243/* number of chars of a literal string without the ending \0 */
244#define LL(x)	(sizeof(x)/sizeof(char) - 1)
245
246#define RETS	"..."
247#define PRE	"[string \""
248#define POS	"\"]"
249
250#define addstr(a,b,l)	( memcpy(a,b,(l) * sizeof(char)), a += (l) )
251
252void luaO_chunkid (char *out, const char *source, size_t bufflen) {
253  size_t l = strlen(source);
254  if (*source == '=') {  /* 'literal' source */
255    if (l <= bufflen)  /* small enough? */
256      memcpy(out, source + 1, l * sizeof(char));
257    else {  /* truncate it */
258      addstr(out, source + 1, bufflen - 1);
259      *out = '\0';
260    }
261  }
262  else if (*source == '@') {  /* file name */
263    if (l <= bufflen)  /* small enough? */
264      memcpy(out, source + 1, l * sizeof(char));
265    else {  /* add '...' before rest of name */
266      addstr(out, RETS, LL(RETS));
267      bufflen -= LL(RETS);
268      memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
269    }
270  }
271  else {  /* string; format as [string "source"] */
272    const char *nl = strchr(source, '\n');  /* find first new line (if any) */
273    addstr(out, PRE, LL(PRE));  /* add prefix */
274    bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
275    if (l < bufflen && nl == NULL) {  /* small one-line source? */
276      addstr(out, source, l);  /* keep it */
277    }
278    else {
279      if (nl != NULL) l = nl - source;  /* stop at first newline */
280      if (l > bufflen) l = bufflen;
281      addstr(out, source, l);
282      addstr(out, RETS, LL(RETS));
283    }
284    memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
285  }
286}
287
288