/src/middleware/lua/lobject.c

  1/*
  2** $Id: lobject.c,v 2.22.1.1 2007/12/27 13:02:25 roberto Exp $
  3** Some generic functions over Lua objects
  4** See Copyright Notice in lua.h
  5*/
  6
  7#include <ctype.h>
  8#include <stdarg.h>
  9#include <stdio.h>
 10#include <stdlib.h>
 11#include <string.h>
 12
 13#define lobject_c
 14#define LUA_CORE
 15
 16#include "lua.h"
 17
 18#include "ldo.h"
 19#include "lmem.h"
 20#include "lobject.h"
 21#include "lstate.h"
 22#include "lstring.h"
 23#include "lvm.h"
 24
 25
 26
 27const TValue luaO_nilobject_ = {{NULL}, LUA_TNIL};
 28
 29
 30/*
 31** converts an integer to a "floating point byte", represented as
 32** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
 33** eeeee != 0 and (xxx) otherwise.
 34*/
 35int luaO_int2fb (unsigned int x) {
 36  int e = 0;  /* expoent */
 37  while (x >= 16) {
 38    x = (x+1) >> 1;
 39    e++;
 40  }
 41  if (x < 8) return x;
 42  else return ((e+1) << 3) | (cast_int(x) - 8);
 43}
 44
 45
 46/* converts back */
 47int luaO_fb2int (int x) {
 48  int e = (x >> 3) & 31;
 49  if (e == 0) return x;
 50  else return ((x & 7)+8) << (e - 1);
 51}
 52
 53
 54int luaO_log2 (unsigned int x) {
 55  static const lu_byte log_2[256] = {
 56    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,
 57    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,
 58    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,
 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    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,
 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  };
 65  int l = -1;
 66  while (x >= 256) { l += 8; x >>= 8; }
 67  return l + log_2[x];
 68
 69}
 70
 71
 72int luaO_rawequalObj (const TValue *t1, const TValue *t2) {
 73  if (ttype(t1) != ttype(t2)) return 0;
 74  else switch (ttype(t1)) {
 75    case LUA_TNIL:
 76      return 1;
 77    case LUA_TNUMBER:
 78      return luai_numeq(nvalue(t1), nvalue(t2));
 79    case LUA_TBOOLEAN:
 80      return bvalue(t1) == bvalue(t2);  /* boolean true must be 1 !! */
 81    case LUA_TLIGHTUSERDATA:
 82      return pvalue(t1) == pvalue(t2);
 83    default:
 84      lua_assert(iscollectable(t1));
 85      return gcvalue(t1) == gcvalue(t2);
 86  }
 87}
 88
 89
 90int luaO_str2d (const char *s, lua_Number *result) {
 91  char *endptr;
 92  *result = lua_str2number(s, &endptr);
 93  if (endptr == s) return 0;  /* conversion failed */
 94  if (*endptr == 'x' || *endptr == 'X')  /* maybe an hexadecimal constant? */
 95    *result = cast_num(strtoul(s, &endptr, 16));
 96  if (*endptr == '\0') return 1;  /* most common case */
 97  while (isspace(cast(unsigned char, *endptr))) endptr++;
 98  if (*endptr != '\0') return 0;  /* invalid trailing characters? */
 99  return 1;
100}
101
102
103
104static void pushstr (lua_State *L, const char *str) {
105  setsvalue2s(L, L->top, luaS_new(L, str));
106  incr_top(L);
107}
108
109
110/* this function handles only `%d', `%c', %f, %p, and `%s' formats */
111const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
112  int n = 1;
113  pushstr(L, "");
114  for (;;) {
115    const char *e = strchr(fmt, '%');
116    if (e == NULL) break;
117    setsvalue2s(L, L->top, luaS_newlstr(L, fmt, e-fmt));
118    incr_top(L);
119    switch (*(e+1)) {
120      case 's': {
121        const char *s = va_arg(argp, char *);
122        if (s == NULL) s = "(null)";
123        pushstr(L, s);
124        break;
125      }
126      case 'c': {
127        char buff[2];
128        buff[0] = cast(char, va_arg(argp, int));
129        buff[1] = '\0';
130        pushstr(L, buff);
131        break;
132      }
133      case 'd': {
134        setnvalue(L->top, cast_num(va_arg(argp, int)));
135        incr_top(L);
136        break;
137      }
138      case 'f': {
139        setnvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
140        incr_top(L);
141        break;
142      }
143      case 'p': {
144        char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
145        sprintf(buff, "%p", va_arg(argp, void *));
146        pushstr(L, buff);
147        break;
148      }
149      case '%': {
150        pushstr(L, "%");
151        break;
152      }
153      default: {
154        char buff[3];
155        buff[0] = '%';
156        buff[1] = *(e+1);
157        buff[2] = '\0';
158        pushstr(L, buff);
159        break;
160      }
161    }
162    n += 2;
163    fmt = e+2;
164  }
165  pushstr(L, fmt);
166  luaV_concat(L, n+1, cast_int(L->top - L->base) - 1);
167  L->top -= n;
168  return svalue(L->top - 1);
169}
170
171
172const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
173  const char *msg;
174  va_list argp;
175  va_start(argp, fmt);
176  msg = luaO_pushvfstring(L, fmt, argp);
177  va_end(argp);
178  return msg;
179}
180
181
182void luaO_chunkid (char *out, const char *source, size_t bufflen) {
183  if (*source == '=') {
184    strncpy(out, source+1, bufflen);  /* remove first char */
185    out[bufflen-1] = '\0';  /* ensures null termination */
186  }
187  else {  /* out = "source", or "...source" */
188    if (*source == '@') {
189      size_t l;
190      source++;  /* skip the `@' */
191      bufflen -= sizeof(" '...' ");
192      l = strlen(source);
193      strcpy(out, "");
194      if (l > bufflen) {
195        source += (l-bufflen);  /* get last part of file name */
196        strcat(out, "...");
197      }
198      strcat(out, source);
199    }
200    else {  /* out = [string "string"] */
201      size_t len = strcspn(source, "\n\r");  /* stop at first newline */
202      bufflen -= sizeof(" [string \"...\"] ");
203      if (len > bufflen) len = bufflen;
204      strcpy(out, "[string \"");
205      if (source[len] != '\0') {  /* must truncate? */
206        strncat(out, source, len);
207        strcat(out, "...");
208      }
209      else
210        strcat(out, source);
211      strcat(out, "\"]");
212    }
213  }
214}