ceph/src/jaegertracing/opentelemetry-cpp/third_party/prometheus-cpp/3rdparty/civetweb/src/third_party/lua-5.4.3/src/lutf8lib.c

   1 /*
   2 ** $Id: lutf8lib.c $
   3 ** Standard library for UTF-8 manipulation
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7 #define lutf8lib_c
   8 #define LUA_LIB
   9
  10 #include "lprefix.h"
  11
  12
  13 #include <assert.h>
  14 #include <limits.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17
  18 #include "lua.h"
  19
  20 #include "lauxlib.h"
  21 #include "lualib.h"
  22
  23
  24 #define MAXUNICODE      0x10FFFFu
  25
  26 #define MAXUTF          0x7FFFFFFFu
  27
  28 /*
  29 ** Integer type for decoded UTF-8 values; MAXUTF needs 31 bits.
  30 */
  31 #if (UINT_MAX >> 30) >= 1
  32 typedef unsigned int utfint;
  33 #else
  34 typedef unsigned long utfint;
  35 #endif
  36
  37
  38 #define iscont(p)       ((*(p) & 0xC0) == 0x80)
  39
  40
  41 /* from strlib */
  42 /* translate a relative string position: negative means back from end */
  43 static lua_Integer u_posrelat (lua_Integer pos, size_t len) {
  44   if (pos >= 0) return pos;
  45   else if (0u - (size_t)pos > len) return 0;
  46   else return (lua_Integer)len + pos + 1;
  47 }
  48
  49
  50 /*
  51 ** Decode one UTF-8 sequence, returning NULL if byte sequence is
  52 ** invalid.  The array 'limits' stores the minimum value for each
  53 ** sequence length, to check for overlong representations. Its first
  54 ** entry forces an error for non-ascii bytes with no continuation
  55 ** bytes (count == 0).
  56 */
  57 static const char *utf8_decode (const char *s, utfint *val, int strict) {
  58   static const utfint limits[] =
  59         {~(utfint)0, 0x80, 0x800, 0x10000u, 0x200000u, 0x4000000u};
  60   unsigned int c = (unsigned char)s[0];
  61   utfint res = 0;  /* final result */
  62   if (c < 0x80)  /* ascii? */
  63     res = c;
  64   else {
  65     int count = 0;  /* to count number of continuation bytes */
  66     for (; c & 0x40; c <<= 1) {  /* while it needs continuation bytes... */
  67       unsigned int cc = (unsigned char)s[++count];  /* read next byte */
  68       if ((cc & 0xC0) != 0x80)  /* not a continuation byte? */
  69         return NULL;  /* invalid byte sequence */
  70       res = (res << 6) | (cc & 0x3F);  /* add lower 6 bits from cont. byte */
  71     }
  72     res |= ((utfint)(c & 0x7F) << (count * 5));  /* add first byte */
  73     if (count > 5 || res > MAXUTF || res < limits[count])
  74       return NULL;  /* invalid byte sequence */
  75     s += count;  /* skip continuation bytes read */
  76   }
  77   if (strict) {
  78     /* check for invalid code points; too large or surrogates */
  79     if (res > MAXUNICODE || (0xD800u <= res && res <= 0xDFFFu))
  80       return NULL;
  81   }
  82   if (val) *val = res;
  83   return s + 1;  /* +1 to include first byte */
  84 }
  85
  86
  87 /*
  88 ** utf8len(s [, i [, j [, lax]]]) --> number of characters that
  89 ** start in the range [i,j], or nil + current position if 's' is not
  90 ** well formed in that interval
  91 */
  92 static int utflen (lua_State *L) {
  93   lua_Integer n = 0;  /* counter for the number of characters */
  94   size_t len;  /* string length in bytes */
  95   const char *s = luaL_checklstring(L, 1, &len);
  96   lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);
  97   lua_Integer posj = u_posrelat(luaL_optinteger(L, 3, -1), len);
  98   int lax = lua_toboolean(L, 4);
  99   luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 2,
 100                    "initial position out of bounds");
 101   luaL_argcheck(L, --posj < (lua_Integer)len, 3,
 102                    "final position out of bounds");
 103   while (posi <= posj) {
 104     const char *s1 = utf8_decode(s + posi, NULL, !lax);
 105     if (s1 == NULL) {  /* conversion error? */
 106       luaL_pushfail(L);  /* return fail ... */
 107       lua_pushinteger(L, posi + 1);  /* ... and current position */
 108       return 2;
 109     }
 110     posi = s1 - s;
 111     n++;
 112   }
 113   lua_pushinteger(L, n);
 114   return 1;
 115 }
 116
 117
 118 /*
 119 ** codepoint(s, [i, [j [, lax]]]) -> returns codepoints for all
 120 ** characters that start in the range [i,j]
 121 */
 122 static int codepoint (lua_State *L) {
 123   size_t len;
 124   const char *s = luaL_checklstring(L, 1, &len);
 125   lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);
 126   lua_Integer pose = u_posrelat(luaL_optinteger(L, 3, posi), len);
 127   int lax = lua_toboolean(L, 4);
 128   int n;
 129   const char *se;
 130   luaL_argcheck(L, posi >= 1, 2, "out of bounds");
 131   luaL_argcheck(L, pose <= (lua_Integer)len, 3, "out of bounds");
 132   if (posi > pose) return 0;  /* empty interval; return no values */
 133   if (pose - posi >= INT_MAX)  /* (lua_Integer -> int) overflow? */
 134     return luaL_error(L, "string slice too long");
 135   n = (int)(pose -  posi) + 1;  /* upper bound for number of returns */
 136   luaL_checkstack(L, n, "string slice too long");
 137   n = 0;  /* count the number of returns */
 138   se = s + pose;  /* string end */
 139   for (s += posi - 1; s < se;) {
 140     utfint code;
 141     s = utf8_decode(s, &code, !lax);
 142     if (s == NULL)
 143       return luaL_error(L, "invalid UTF-8 code");
 144     lua_pushinteger(L, code);
 145     n++;
 146   }
 147   return n;
 148 }
 149
 150
 151 static void pushutfchar (lua_State *L, int arg) {
 152   lua_Unsigned code = (lua_Unsigned)luaL_checkinteger(L, arg);
 153   luaL_argcheck(L, code <= MAXUTF, arg, "value out of range");
 154   lua_pushfstring(L, "%U", (long)code);
 155 }
 156
 157
 158 /*
 159 ** utfchar(n1, n2, ...)  -> char(n1)..char(n2)...
 160 */
 161 static int utfchar (lua_State *L) {
 162   int n = lua_gettop(L);  /* number of arguments */
 163   if (n == 1)  /* optimize common case of single char */
 164     pushutfchar(L, 1);
 165   else {
 166     int i;
 167     luaL_Buffer b;
 168     luaL_buffinit(L, &b);
 169     for (i = 1; i <= n; i++) {
 170       pushutfchar(L, i);
 171       luaL_addvalue(&b);
 172     }
 173     luaL_pushresult(&b);
 174   }
 175   return 1;
 176 }
 177
 178
 179 /*
 180 ** offset(s, n, [i])  -> index where n-th character counting from
 181 **   position 'i' starts; 0 means character at 'i'.
 182 */
 183 static int byteoffset (lua_State *L) {
 184   size_t len;
 185   const char *s = luaL_checklstring(L, 1, &len);
 186   lua_Integer n  = luaL_checkinteger(L, 2);
 187   lua_Integer posi = (n >= 0) ? 1 : len + 1;
 188   posi = u_posrelat(luaL_optinteger(L, 3, posi), len);
 189   luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 3,
 190                    "position out of bounds");
 191   if (n == 0) {
 192     /* find beginning of current byte sequence */
 193     while (posi > 0 && iscont(s + posi)) posi--;
 194   }
 195   else {
 196     if (iscont(s + posi))
 197       return luaL_error(L, "initial position is a continuation byte");
 198     if (n < 0) {
 199        while (n < 0 && posi > 0) {  /* move back */
 200          do {  /* find beginning of previous character */
 201            posi--;
 202          } while (posi > 0 && iscont(s + posi));
 203          n++;
 204        }
 205      }
 206      else {
 207        n--;  /* do not move for 1st character */
 208        while (n > 0 && posi < (lua_Integer)len) {
 209          do {  /* find beginning of next character */
 210            posi++;
 211          } while (iscont(s + posi));  /* (cannot pass final '\0') */
 212          n--;
 213        }
 214      }
 215   }
 216   if (n == 0)  /* did it find given character? */
 217     lua_pushinteger(L, posi + 1);
 218   else  /* no such character */
 219     luaL_pushfail(L);
 220   return 1;
 221 }
 222
 223
 224 static int iter_aux (lua_State *L, int strict) {
 225   size_t len;
 226   const char *s = luaL_checklstring(L, 1, &len);
 227   lua_Integer n = lua_tointeger(L, 2) - 1;
 228   if (n < 0)  /* first iteration? */
 229     n = 0;  /* start from here */
 230   else if (n < (lua_Integer)len) {
 231     n++;  /* skip current byte */
 232     while (iscont(s + n)) n++;  /* and its continuations */
 233   }
 234   if (n >= (lua_Integer)len)
 235     return 0;  /* no more codepoints */
 236   else {
 237     utfint code;
 238     const char *next = utf8_decode(s + n, &code, strict);
 239     if (next == NULL)
 240       return luaL_error(L, "invalid UTF-8 code");
 241     lua_pushinteger(L, n + 1);
 242     lua_pushinteger(L, code);
 243     return 2;
 244   }
 245 }
 246
 247
 248 static int iter_auxstrict (lua_State *L) {
 249   return iter_aux(L, 1);
 250 }
 251
 252 static int iter_auxlax (lua_State *L) {
 253   return iter_aux(L, 0);
 254 }
 255
 256
 257 static int iter_codes (lua_State *L) {
 258   int lax = lua_toboolean(L, 2);
 259   luaL_checkstring(L, 1);
 260   lua_pushcfunction(L, lax ? iter_auxlax : iter_auxstrict);
 261   lua_pushvalue(L, 1);
 262   lua_pushinteger(L, 0);
 263   return 3;
 264 }
 265
 266
 267 /* pattern to match a single UTF-8 character */
 268 #define UTF8PATT        "[\0-\x7F\xC2-\xFD][\x80-\xBF]*"
 269
 270
 271 static const luaL_Reg funcs[] = {
 272   {"offset", byteoffset},
 273   {"codepoint", codepoint},
 274   {"char", utfchar},
 275   {"len", utflen},
 276   {"codes", iter_codes},
 277   /* placeholders */
 278   {"charpattern", NULL},
 279   {NULL, NULL}
 280 };
 281
 282
 283 LUAMOD_API int luaopen_utf8 (lua_State *L) {
 284   luaL_newlib(L, funcs);
 285   lua_pushlstring(L, UTF8PATT, sizeof(UTF8PATT)/sizeof(char) - 1);
 286   lua_setfield(L, -2, "charpattern");
 287   return 1;
 288 }
 289