gcc/mbchar.c

   1 /* Multibyte Character Functions.
   2    Copyright (C) 1998 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* Note regarding cross compilation:
  22
  23    In general, translation of multibyte characters to wide characters can
  24    only work in a native compiler since the translation function (mbtowc)
  25    needs to know about both the source and target character encoding.  However,
  26    this particular implementation for JIS, SJIS and EUCJP source characters
  27    will work for any compiler with a newlib target.  Other targets may also
  28    work provided that their wchar_t implementation is 2 bytes and the encoding
  29    leaves the source character values unchanged (except for removing the
  30    state shifting markers).  */
  31
  32 #include "config.h"
  33 #ifdef MULTIBYTE_CHARS
  34 #include "system.h"
  35 #include "mbchar.h"
  36 #include <locale.h>
  37
  38 typedef enum {ESCAPE, DOLLAR, BRACKET, AT, B, J, NUL, JIS_CHAR, OTHER,
  39               JIS_C_NUM} JIS_CHAR_TYPE;
  40
  41 typedef enum {ASCII, A_ESC, A_ESC_DL, JIS, JIS_1, JIS_2, J_ESC, J_ESC_BR,
  42              J2_ESC, J2_ESC_BR, INV, JIS_S_NUM} JIS_STATE;
  43
  44 typedef enum {COPYA, COPYJ, COPYJ2, MAKE_A, MAKE_J, NOOP,
  45               EMPTY, ERROR} JIS_ACTION;
  46
  47 /* State/action tables for processing JIS encoding:
  48
  49    Where possible, switches to JIS are grouped with proceding JIS characters
  50    and switches to ASCII are grouped with preceding JIS characters.
  51    Thus, maximum returned length is:
  52      2 (switch to JIS) + 2 (JIS characters) + 2 (switch back to ASCII) = 6.  */
  53
  54 static JIS_STATE JIS_state_table[JIS_S_NUM][JIS_C_NUM] = {
  55 /*            ESCAPE DOLLAR   BRACKET   AT     B      J     NUL JIS_CHAR OTH*/
  56 /*ASCII*/   { A_ESC, ASCII,   ASCII,    ASCII, ASCII, ASCII, ASCII,ASCII,ASCII},
  57 /*A_ESC*/   { ASCII, A_ESC_DL,ASCII,    ASCII, ASCII, ASCII, ASCII,ASCII,ASCII},
  58 /*A_ESC_DL*/{ ASCII, ASCII,   ASCII,    JIS,   JIS,   ASCII, ASCII,ASCII,ASCII},
  59 /*JIS*/     { J_ESC, JIS_1,   JIS_1,    JIS_1, JIS_1, JIS_1, INV,  JIS_1,INV },
  60 /*JIS_1*/   { INV,   JIS_2,   JIS_2,    JIS_2, JIS_2, JIS_2, INV,  JIS_2,INV },
  61 /*JIS_2*/   { J2_ESC,JIS,     JIS,      JIS,   JIS,   JIS,   INV,  JIS,  JIS },
  62 /*J_ESC*/   { INV,   INV,     J_ESC_BR, INV,   INV,   INV,   INV,  INV,  INV },
  63 /*J_ESC_BR*/{ INV,   INV,     INV,      INV,   ASCII, ASCII, INV,  INV,  INV },
  64 /*J2_ESC*/  { INV,   INV,     J2_ESC_BR,INV,   INV,   INV,   INV,  INV,  INV },
  65 /*J2_ESC_BR*/{INV,   INV,     INV,      INV,   ASCII, ASCII, INV,  INV,  INV },
  66 };
  67
  68 static JIS_ACTION JIS_action_table[JIS_S_NUM][JIS_C_NUM] = {
  69 /*            ESCAPE DOLLAR BRACKET AT     B       J      NUL  JIS_CHAR OTH */
  70 /*ASCII */   {NOOP,  COPYA, COPYA, COPYA,  COPYA,  COPYA, EMPTY, COPYA, COPYA},
  71 /*A_ESC */   {COPYA, NOOP,  COPYA, COPYA,  COPYA,  COPYA, COPYA, COPYA, COPYA},
  72 /*A_ESC_DL */{COPYA, COPYA, COPYA, MAKE_J, MAKE_J, COPYA, COPYA, COPYA, COPYA},
  73 /*JIS */     {NOOP,  NOOP,  NOOP,  NOOP,   NOOP,   NOOP,  ERROR, NOOP,  ERROR},
  74 /*JIS_1 */   {ERROR, NOOP,  NOOP,  NOOP,   NOOP,   NOOP,  ERROR, NOOP,  ERROR},
  75 /*JIS_2 */   {NOOP,  COPYJ2,COPYJ2,COPYJ2, COPYJ2, COPYJ2,ERROR, COPYJ2,COPYJ2},
  76 /*J_ESC */   {ERROR, ERROR, NOOP,  ERROR,  ERROR,  ERROR, ERROR, ERROR, ERROR},
  77 /*J_ESC_BR */{ERROR, ERROR, ERROR, ERROR,  NOOP,   NOOP,  ERROR, ERROR, ERROR},
  78 /*J2_ESC */  {ERROR, ERROR, NOOP,  ERROR,  ERROR,  ERROR, ERROR, ERROR, ERROR},
  79 /*J2_ESC_BR*/{ERROR, ERROR, ERROR, ERROR,  COPYJ,  COPYJ, ERROR, ERROR, ERROR},
  80 };
  81
  82
  83 const char *literal_codeset = NULL;
  84
  85 /* Store into *PWC (if PWC is not null) the wide character
  86    corresponding to the multibyte character at the start of the
  87    buffer S of size N.  Return the number of bytes in the multibyte
  88    character.  Return -1 if the bytes do not form a valid character,
  89    or 0 if S is null or points to a null byte.
  90
  91    This function behaves like the Standard C function mbtowc, except
  92    it treats locale names of the form "C-..." specially.  */
  93
  94 int
  95 local_mbtowc (pwc, s, n)
  96      wchar_t *pwc;
  97      const char *s;
  98      size_t n;
  99 {
 100   static JIS_STATE save_state = ASCII;
 101   JIS_STATE curr_state = save_state;
 102   const unsigned char *t = (const unsigned char *) s;
 103
 104   if (s != NULL && n == 0)
 105     return -1;
 106
 107   if (literal_codeset == NULL || strlen (literal_codeset) <= 1)
 108     /* This must be the "C" locale or unknown locale -- fall thru */
 109     ;
 110   else if (! strcmp (literal_codeset, "C-SJIS"))
 111     {
 112       int char1;
 113       if (s == NULL)
 114         /* Not state-dependent.  */
 115         return 0;
 116
 117       char1 = *t;
 118       if (ISSJIS1 (char1))
 119         {
 120           int char2 = t[1];
 121
 122           if (n <= 1)
 123             return -1;
 124
 125           if (ISSJIS2 (char2))
 126             {
 127               if (pwc != NULL)
 128                 *pwc = (((wchar_t) *t) << 8) + (wchar_t) (*(t + 1));
 129               return 2;
 130             }
 131
 132           return -1;
 133         }
 134
 135       if (pwc != NULL)
 136         *pwc = (wchar_t) *t;
 137
 138       if (*t == '\0')
 139         return 0;
 140
 141       return 1;
 142     }
 143   else if (! strcmp (literal_codeset, "C-EUCJP"))
 144     {
 145       int char1;
 146
 147       if (s == NULL)
 148         /* Not state-dependent.  */
 149         return 0;
 150
 151       char1 = *t;
 152       if (ISEUCJP (char1))
 153         {
 154           int char2 = t[1];
 155
 156           if (n <= 1)
 157             return -1;
 158
 159           if (ISEUCJP (char2))
 160             {
 161               if (pwc != NULL)
 162                 *pwc = (((wchar_t) *t) << 8) + (wchar_t) (*(t + 1));
 163               return 2;
 164             }
 165
 166           return -1;
 167         }
 168
 169       if (pwc != NULL)
 170         *pwc = (wchar_t) *t;
 171
 172       if (*t == '\0')
 173         return 0;
 174
 175       return 1;
 176     }
 177   else if (! strcmp (literal_codeset, "C-JIS"))
 178     {
 179       JIS_ACTION action;
 180       JIS_CHAR_TYPE ch;
 181       const unsigned char *ptr;
 182       size_t i, curr_ch;
 183
 184       if (s == NULL)
 185         {
 186           save_state = ASCII;
 187           /* State-dependent. */
 188           return 1;
 189         }
 190
 191       ptr = t;
 192
 193       for (i = 0; i < n; i++)
 194         {
 195           curr_ch = t[i];
 196           switch (curr_ch)
 197             {
 198             case JIS_ESC_CHAR:
 199               ch = ESCAPE;
 200               break;
 201             case '$':
 202               ch = DOLLAR;
 203               break;
 204             case '@':
 205               ch = AT;
 206               break;
 207             case '(':
 208               ch = BRACKET;
 209               break;
 210             case 'B':
 211               ch = B;
 212               break;
 213             case 'J':
 214               ch = J;
 215               break;
 216             case '\0':
 217               ch = NUL;
 218               break;
 219             default:
 220               if (ISJIS (curr_ch))
 221                 ch = JIS_CHAR;
 222               else
 223                 ch = OTHER;
 224             }
 225
 226           action = JIS_action_table[curr_state][ch];
 227           curr_state = JIS_state_table[curr_state][ch];
 228
 229           switch (action)
 230             {
 231             case NOOP:
 232               break;
 233
 234             case EMPTY:
 235               if (pwc != NULL)
 236                 *pwc = (wchar_t) 0;
 237
 238               save_state = curr_state;
 239               return i;
 240
 241             case COPYA:
 242               if (pwc != NULL)
 243                 *pwc = (wchar_t) *ptr;
 244               save_state = curr_state;
 245               return i + 1;
 246
 247             case COPYJ:
 248               if (pwc != NULL)
 249                 *pwc = (((wchar_t) *ptr) << 8) + (wchar_t) (*(ptr + 1));
 250
 251               save_state = curr_state;
 252               return i + 1;
 253
 254             case COPYJ2:
 255               if (pwc != NULL)
 256                 *pwc = (((wchar_t) *ptr) << 8) + (wchar_t) (*(ptr + 1));
 257
 258               save_state = curr_state;
 259               return ptr - t + 2;
 260
 261             case MAKE_A:
 262             case MAKE_J:
 263               ptr = (const unsigned char *) (t + i + 1);
 264               break;
 265
 266             case ERROR:
 267             default:
 268               return -1;
 269             }
 270         }
 271
 272       /* More than n bytes needed.  */
 273       return -1;
 274     }
 275
 276 #ifdef CROSS_COMPILE
 277   if (s == NULL)
 278     /* Not state-dependent.  */
 279     return 0;
 280
 281   if (pwc != NULL)
 282     *pwc = *s;
 283   return 1;
 284 #else
 285
 286   /* This must be the "C" locale or unknown locale. */
 287   return mbtowc (pwc, s, n);
 288 #endif
 289 }
 290
 291 /* Return the number of bytes in the multibyte character at the start
 292    of the buffer S of size N.  Return -1 if the bytes do not form a
 293    valid character, or 0 if S is null or points to a null byte.
 294
 295    This function behaves like the Standard C function mblen, except
 296    it treats locale names of the form "C-..." specially.  */
 297
 298 int
 299 local_mblen (s, n)
 300      const char *s;
 301      size_t n;
 302 {
 303   return local_mbtowc (NULL, s, n);
 304 }
 305
 306 /* Return the maximum mumber of bytes in a multibyte character.
 307
 308    This function returns the same value as the Standard C macro MB_CUR_MAX,
 309    except it treats locale names of the form "C-..." specially.  */
 310
 311 int
 312 local_mb_cur_max ()
 313 {
 314   if (literal_codeset == NULL || strlen (literal_codeset) <= 1)
 315     ;
 316   else if (! strcmp (literal_codeset, "C-SJIS"))
 317     return 2;
 318   else if (! strcmp (literal_codeset, "C-EUCJP"))
 319     return 2;
 320   else if (! strcmp (literal_codeset, "C-JIS"))
 321     return 8; /* 3 + 2 + 3 */
 322
 323 #ifdef CROSS_COMPILE
 324   return 1;
 325 #else
 326   if (MB_CUR_MAX > 0)
 327     return MB_CUR_MAX;
 328
 329   return 1; /* default */
 330 #endif
 331 }
 332 #else  /* MULTIBYTE_CHARS */
 333 extern int dummy;  /* silence 'ANSI C forbids an empty source file' warning */
 334 #endif /* MULTIBYTE_CHARS */