1 /* Tables for conversion to and from ISO-IR-165. 2 converting from UCS using gaps. 3 Copyright (C) 2000-2022 Free Software Foundation, Inc. 4 This file is part of the GNU C Library. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library 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 GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, see 18 <https://www.gnu.org/licenses/>. */ 19 20 #ifndef _ISO_IR_165_H 21 #define _ISO_IR_165_H 1 22 23 #include <gconv.h> 24 #include <stdint.h> 25 26 struct gap 27 { 28 uint16_t start; 29 uint16_t end; 30 int32_t idx; 31 }; 32 33 /* Table for ISO-IR-165 (CCITT Chinese) to UCS4 conversion. */ 34 #define ISOIR165_FROMSIZE 0x2284 35 extern const uint16_t __isoir165_to_tab[ISOIR165_FROMSIZE]; 36 37 38 /* XXX If we at some point need an offset value to decode the byte 39 sequences another parameter can be added. */ uint32_t(always_inline)40static inline uint32_t 41 __attribute ((always_inline)) 42 isoir165_to_ucs4 (const unsigned char **s, size_t avail) 43 { 44 unsigned char ch = *(*s); 45 unsigned char ch2; 46 uint32_t res; 47 48 if (ch <= 0x20 || ch >= 0x7f) 49 return __UNKNOWN_10646_CHAR; 50 51 if (avail < 2) 52 return 0; 53 54 ch2 = (*s)[1]; 55 if (ch2 <= 0x20 || ch2 >= 0x7f) 56 return __UNKNOWN_10646_CHAR; 57 58 res = __isoir165_to_tab[(ch - 0x21) * 94 + (ch2 - 0x21)]; 59 if (res == 0) 60 return __UNKNOWN_10646_CHAR; 61 62 *s += 2; 63 return res; 64 } 65 66 67 /* Tables for ISO-IR-165 (CCITT Chinese) from UCS4 conversion. */ 68 extern const struct gap __isoir165_from_idx[]; 69 extern const char __isoir165_from_tab[]; 70 size_t(always_inline)71static inline size_t 72 __attribute ((always_inline)) 73 ucs4_to_isoir165 (uint32_t wch, unsigned char *s, size_t avail) 74 { 75 unsigned int ch = (unsigned int) wch; 76 const char *cp; 77 const struct gap *rp = __isoir165_from_idx; 78 79 if (ch > 0xffe5) 80 /* This is an illegal character. */ 81 return __UNKNOWN_10646_CHAR; 82 83 while (ch > rp->end) 84 ++rp; 85 if (ch < rp->start) 86 /* This is an illegal character. */ 87 return __UNKNOWN_10646_CHAR; 88 89 /* The two bytes following the index given in this record give the 90 encoding in ISO-IR-165. Unless the bytes are zero. */ 91 cp = &__isoir165_from_tab[(ch + rp->idx) * 2]; 92 if (*cp == '\0') 93 /* This is an illegal character. */ 94 return __UNKNOWN_10646_CHAR; 95 96 if (avail < 2) 97 return 0; 98 99 s[0] = cp[0]; 100 s[1] = cp[1]; 101 102 return 2; 103 } 104 105 #endif /* iso-ir-165.h */ 106