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
28 LUAI_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 */
luaO_int2fb(unsigned int x)36 int 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 */
luaO_fb2int(int x)48 int 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
luaO_ceillog2(unsigned int x)55 int 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
luaO_arith(int op,lua_Number v1,lua_Number v2)73 lua_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
luaO_hexavalue(int c)87 int 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
isneg(const char ** s)98 static int isneg (const char **s) {
99 if (**s == '-') { (*s)++; return 1; }
100 else if (**s == '+') (*s)++;
101 return 0;
102 }
103
104
readhexa(const char ** s,lua_Number r,int * count)105 static 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 */
lua_strx2number(const char * s,char ** endptr)118 static 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
luaO_str2d(const char * s,size_t len,lua_Number * result)158 int 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
pushstr(lua_State * L,const char * str,size_t l)173 static 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 */
luaO_pushvfstring(lua_State * L,const char * fmt,va_list argp)179 const 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
luaO_pushfstring(lua_State * L,const char * fmt,...)233 const 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
luaO_chunkid(char * out,const char * source,size_t bufflen)252 void 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