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Diffstat (limited to 'lib/striconv.c')
| -rw-r--r-- | lib/striconv.c | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/lib/striconv.c b/lib/striconv.c new file mode 100644 index 0000000..d3da10a --- /dev/null +++ b/lib/striconv.c @@ -0,0 +1,451 @@ +/* Charset conversion. + Copyright (C) 2001-2007, 2010-2022 Free Software Foundation, Inc. + Written by Bruno Haible and Simon Josefsson. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + This file is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include "striconv.h" + +#include <errno.h> +#include <stdlib.h> +#include <string.h> + +#if HAVE_ICONV +# include <iconv.h> +/* Get MB_LEN_MAX, CHAR_BIT. */ +# include <limits.h> +#endif + +#include "c-strcase.h" + +#ifndef SIZE_MAX +# define SIZE_MAX ((size_t) -1) +#endif + + +#if HAVE_ICONV + +int +mem_cd_iconv (const char *src, size_t srclen, iconv_t cd, + char **resultp, size_t *lengthp) +{ +# define tmpbufsize 4096 + size_t length; + char *result; + + /* Avoid glibc-2.1 bug and Solaris 2.7-2.9 bug. */ +# if defined _LIBICONV_VERSION \ + || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \ + || defined __sun) + /* Set to the initial state. */ + iconv (cd, NULL, NULL, NULL, NULL); +# endif + + /* Determine the length we need. */ + { + size_t count = 0; + /* The alignment is needed when converting e.g. to glibc's WCHAR_T or + libiconv's UCS-4-INTERNAL encoding. */ + union { unsigned int align; char buf[tmpbufsize]; } tmp; +# define tmpbuf tmp.buf + const char *inptr = src; + size_t insize = srclen; + + while (insize > 0) + { + char *outptr = tmpbuf; + size_t outsize = tmpbufsize; + size_t res = iconv (cd, + (ICONV_CONST char **) &inptr, &insize, + &outptr, &outsize); + + if (res == (size_t)(-1)) + { + if (errno == E2BIG) + ; + else if (errno == EINVAL) + break; + else + return -1; + } +# if !defined _LIBICONV_VERSION && !(defined __GLIBC__ && !defined __UCLIBC__) + /* Irix iconv() inserts a NUL byte if it cannot convert. + NetBSD iconv() inserts a question mark if it cannot convert. + Only GNU libiconv and GNU libc are known to prefer to fail rather + than doing a lossy conversion. */ + else if (res > 0) + { + errno = EILSEQ; + return -1; + } +# endif + count += outptr - tmpbuf; + } + /* Avoid glibc-2.1 bug and Solaris 2.7 bug. */ +# if defined _LIBICONV_VERSION \ + || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \ + || defined __sun) + { + char *outptr = tmpbuf; + size_t outsize = tmpbufsize; + size_t res = iconv (cd, NULL, NULL, &outptr, &outsize); + + if (res == (size_t)(-1)) + return -1; + count += outptr - tmpbuf; + } +# endif + length = count; +# undef tmpbuf + } + + if (length == 0) + { + *lengthp = 0; + return 0; + } + if (*resultp != NULL && *lengthp >= length) + result = *resultp; + else + { + result = (char *) malloc (length); + if (result == NULL) + { + errno = ENOMEM; + return -1; + } + } + + /* Avoid glibc-2.1 bug and Solaris 2.7-2.9 bug. */ +# if defined _LIBICONV_VERSION \ + || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \ + || defined __sun) + /* Return to the initial state. */ + iconv (cd, NULL, NULL, NULL, NULL); +# endif + + /* Do the conversion for real. */ + { + const char *inptr = src; + size_t insize = srclen; + char *outptr = result; + size_t outsize = length; + + while (insize > 0) + { + size_t res = iconv (cd, + (ICONV_CONST char **) &inptr, &insize, + &outptr, &outsize); + + if (res == (size_t)(-1)) + { + if (errno == EINVAL) + break; + else + goto fail; + } +# if !defined _LIBICONV_VERSION && !(defined __GLIBC__ && !defined __UCLIBC__) + /* Irix iconv() inserts a NUL byte if it cannot convert. + NetBSD iconv() inserts a question mark if it cannot convert. + Only GNU libiconv and GNU libc are known to prefer to fail rather + than doing a lossy conversion. */ + else if (res > 0) + { + errno = EILSEQ; + goto fail; + } +# endif + } + /* Avoid glibc-2.1 bug and Solaris 2.7 bug. */ +# if defined _LIBICONV_VERSION \ + || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \ + || defined __sun) + { + size_t res = iconv (cd, NULL, NULL, &outptr, &outsize); + + if (res == (size_t)(-1)) + goto fail; + } +# endif + if (outsize != 0) + abort (); + } + + *resultp = result; + *lengthp = length; + + return 0; + + fail: + { + if (result != *resultp) + free (result); + return -1; + } +# undef tmpbufsize +} + +char * +str_cd_iconv (const char *src, iconv_t cd) +{ + /* For most encodings, a trailing NUL byte in the input will be converted + to a trailing NUL byte in the output. But not for UTF-7. So that this + function is usable for UTF-7, we have to exclude the NUL byte from the + conversion and add it by hand afterwards. */ +# if !defined _LIBICONV_VERSION && !(defined __GLIBC__ && !defined __UCLIBC__) + /* Irix iconv() inserts a NUL byte if it cannot convert. + NetBSD iconv() inserts a question mark if it cannot convert. + Only GNU libiconv and GNU libc are known to prefer to fail rather + than doing a lossy conversion. For other iconv() implementations, + we have to look at the number of irreversible conversions returned; + but this information is lost when iconv() returns for an E2BIG reason. + Therefore we cannot use the second, faster algorithm. */ + + char *result = NULL; + size_t length = 0; + int retval = mem_cd_iconv (src, strlen (src), cd, &result, &length); + char *final_result; + + if (retval < 0) + { + if (result != NULL) + abort (); + return NULL; + } + + /* Add the terminating NUL byte. */ + final_result = + (result != NULL ? realloc (result, length + 1) : malloc (length + 1)); + if (final_result == NULL) + { + free (result); + errno = ENOMEM; + return NULL; + } + final_result[length] = '\0'; + + return final_result; + +# else + /* This algorithm is likely faster than the one above. But it may produce + iconv() returns for an E2BIG reason, when the output size guess is too + small. Therefore it can only be used when we don't need the number of + irreversible conversions performed. */ + char *result; + size_t result_size; + size_t length; + const char *inptr = src; + size_t inbytes_remaining = strlen (src); + + /* Make a guess for the worst-case output size, in order to avoid a + realloc. It's OK if the guess is wrong as long as it is not zero and + doesn't lead to an integer overflow. */ + result_size = inbytes_remaining; + { + size_t approx_sqrt_SIZE_MAX = SIZE_MAX >> (sizeof (size_t) * CHAR_BIT / 2); + if (result_size <= approx_sqrt_SIZE_MAX / MB_LEN_MAX) + result_size *= MB_LEN_MAX; + } + result_size += 1; /* for the terminating NUL */ + + result = (char *) malloc (result_size); + if (result == NULL) + { + errno = ENOMEM; + return NULL; + } + + /* Avoid glibc-2.1 bug and Solaris 2.7-2.9 bug. */ +# if defined _LIBICONV_VERSION \ + || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \ + || defined __sun) + /* Set to the initial state. */ + iconv (cd, NULL, NULL, NULL, NULL); +# endif + + /* Do the conversion. */ + { + char *outptr = result; + size_t outbytes_remaining = result_size - 1; + + for (;;) + { + /* Here inptr + inbytes_remaining = src + strlen (src), + outptr + outbytes_remaining = result + result_size - 1. */ + size_t res = iconv (cd, + (ICONV_CONST char **) &inptr, &inbytes_remaining, + &outptr, &outbytes_remaining); + + if (res == (size_t)(-1)) + { + if (errno == EINVAL) + break; + else if (errno == E2BIG) + { + size_t used = outptr - result; + size_t newsize = result_size * 2; + char *newresult; + + if (!(newsize > result_size)) + { + errno = ENOMEM; + goto failed; + } + newresult = (char *) realloc (result, newsize); + if (newresult == NULL) + { + errno = ENOMEM; + goto failed; + } + result = newresult; + result_size = newsize; + outptr = result + used; + outbytes_remaining = result_size - 1 - used; + } + else + goto failed; + } + else + break; + } + /* Avoid glibc-2.1 bug and Solaris 2.7 bug. */ +# if defined _LIBICONV_VERSION \ + || !(((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \ + || defined __sun) + for (;;) + { + /* Here outptr + outbytes_remaining = result + result_size - 1. */ + size_t res = iconv (cd, NULL, NULL, &outptr, &outbytes_remaining); + + if (res == (size_t)(-1)) + { + if (errno == E2BIG) + { + size_t used = outptr - result; + size_t newsize = result_size * 2; + char *newresult; + + if (!(newsize > result_size)) + { + errno = ENOMEM; + goto failed; + } + newresult = (char *) realloc (result, newsize); + if (newresult == NULL) + { + errno = ENOMEM; + goto failed; + } + result = newresult; + result_size = newsize; + outptr = result + used; + outbytes_remaining = result_size - 1 - used; + } + else + goto failed; + } + else + break; + } +# endif + + /* Add the terminating NUL byte. */ + *outptr++ = '\0'; + + length = outptr - result; + } + + /* Give away unused memory. */ + if (length < result_size) + { + char *smaller_result = (char *) realloc (result, length); + + if (smaller_result != NULL) + result = smaller_result; + } + + return result; + + failed: + free (result); + return NULL; + +# endif +} + +#endif + +char * +str_iconv (const char *src, const char *from_codeset, const char *to_codeset) +{ + if (*src == '\0' || c_strcasecmp (from_codeset, to_codeset) == 0) + { + char *result = strdup (src); + + if (result == NULL) + errno = ENOMEM; + return result; + } + else + { +#if HAVE_ICONV + iconv_t cd; + char *result; + + /* Avoid glibc-2.1 bug with EUC-KR. */ +# if ((__GLIBC__ == 2 && __GLIBC_MINOR__ <= 1) && !defined __UCLIBC__) \ + && !defined _LIBICONV_VERSION + if (c_strcasecmp (from_codeset, "EUC-KR") == 0 + || c_strcasecmp (to_codeset, "EUC-KR") == 0) + { + errno = EINVAL; + return NULL; + } +# endif + cd = iconv_open (to_codeset, from_codeset); + if (cd == (iconv_t) -1) + return NULL; + + result = str_cd_iconv (src, cd); + + if (result == NULL) + { + /* Close cd, but preserve the errno from str_cd_iconv. */ + int saved_errno = errno; + iconv_close (cd); + errno = saved_errno; + } + else + { + if (iconv_close (cd) < 0) + { + free (result); + return NULL; + } + } + return result; +#else + /* This is a different error code than if iconv_open existed but didn't + support from_codeset and to_codeset, so that the caller can emit + an error message such as + "iconv() is not supported. Installing GNU libiconv and + then reinstalling this package would fix this." */ + errno = ENOSYS; + return NULL; +#endif + } +} |