1/* Convert UTF-32 string to UTF-8 string. 2 Copyright (C) 2002, 2006-2007, 2009-2010 Free Software Foundation, Inc. 3 Written by Bruno Haible <bruno@clisp.org>, 2002. 4 5 This program is free software: you can redistribute it and/or modify it 6 under the terms of the GNU Lesser General Public License as published 7 by the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18#include <config.h> 19 20/* Specification. */ 21#include "unistr.h" 22 23#define FUNC u32_to_u8 24#define SRC_UNIT uint32_t 25#define DST_UNIT uint8_t 26 27#include <errno.h> 28#include <stdlib.h> 29#include <string.h> 30 31DST_UNIT * 32FUNC (const SRC_UNIT *s, size_t n, DST_UNIT *resultbuf, size_t *lengthp) 33{ 34 const SRC_UNIT *s_end = s + n; 35 /* Output string accumulator. */ 36 DST_UNIT *result; 37 size_t allocated; 38 size_t length; 39 40 if (resultbuf != NULL) 41 { 42 result = resultbuf; 43 allocated = *lengthp; 44 } 45 else 46 { 47 result = NULL; 48 allocated = 0; 49 } 50 length = 0; 51 /* Invariants: 52 result is either == resultbuf or == NULL or malloc-allocated. 53 If length > 0, then result != NULL. */ 54 55 while (s < s_end) 56 { 57 ucs4_t uc; 58 int count; 59 60 /* Fetch a Unicode character from the input string. */ 61 uc = *s++; 62 /* No need to call the safe variant u32_mbtouc, because 63 u8_uctomb will verify uc anyway. */ 64 65 /* Store it in the output string. */ 66 count = u8_uctomb (result + length, uc, allocated - length); 67 if (count == -1) 68 { 69 if (!(result == resultbuf || result == NULL)) 70 free (result); 71 errno = EILSEQ; 72 return NULL; 73 } 74 if (count == -2) 75 { 76 DST_UNIT *memory; 77 78 allocated = (allocated > 0 ? 2 * allocated : 12); 79 if (length + 6 > allocated) 80 allocated = length + 6; 81 if (result == resultbuf || result == NULL) 82 memory = (DST_UNIT *) malloc (allocated * sizeof (DST_UNIT)); 83 else 84 memory = 85 (DST_UNIT *) realloc (result, allocated * sizeof (DST_UNIT)); 86 87 if (memory == NULL) 88 { 89 if (!(result == resultbuf || result == NULL)) 90 free (result); 91 errno = ENOMEM; 92 return NULL; 93 } 94 if (result == resultbuf && length > 0) 95 memcpy ((char *) memory, (char *) result, 96 length * sizeof (DST_UNIT)); 97 result = memory; 98 count = u8_uctomb (result + length, uc, allocated - length); 99 if (count < 0) 100 abort (); 101 } 102 length += count; 103 } 104 105 if (length == 0) 106 { 107 if (result == NULL) 108 { 109 /* Return a non-NULL value. NULL means error. */ 110 result = (DST_UNIT *) malloc (1); 111 if (result == NULL) 112 { 113 errno = ENOMEM; 114 return NULL; 115 } 116 } 117 } 118 else if (result != resultbuf && length < allocated) 119 { 120 /* Shrink the allocated memory if possible. */ 121 DST_UNIT *memory; 122 123 memory = (DST_UNIT *) realloc (result, length * sizeof (DST_UNIT)); 124 if (memory != NULL) 125 result = memory; 126 } 127 128 *lengthp = length; 129 return result; 130} 131