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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 #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