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Diffstat (limited to 'lib/iconv_open.c')
| -rw-r--r-- | lib/iconv_open.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/lib/iconv_open.c b/lib/iconv_open.c new file mode 100644 index 0000000..be70de2 --- /dev/null +++ b/lib/iconv_open.c @@ -0,0 +1,173 @@ +/* Character set conversion. + Copyright (C) 2007, 2009-2023 Free Software Foundation, Inc. + + 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 <iconv.h> + +#include <errno.h> +#include <string.h> +#include "c-ctype.h" +#include "c-strcase.h" + +#define SIZEOF(a) (sizeof(a) / sizeof(a[0])) + +/* Namespace cleanliness. */ +#define mapping_lookup rpl_iconv_open_mapping_lookup + +/* The macro ICONV_FLAVOR is defined to one of these or undefined. */ + +#define ICONV_FLAVOR_AIX "iconv_open-aix.h" +#define ICONV_FLAVOR_HPUX "iconv_open-hpux.h" +#define ICONV_FLAVOR_IRIX "iconv_open-irix.h" +#define ICONV_FLAVOR_OSF "iconv_open-osf.h" +#define ICONV_FLAVOR_SOLARIS "iconv_open-solaris.h" +#define ICONV_FLAVOR_ZOS "iconv_open-zos.h" + +#ifdef ICONV_FLAVOR +# include ICONV_FLAVOR +#endif + +iconv_t +rpl_iconv_open (const char *tocode, const char *fromcode) +#undef iconv_open +{ + char fromcode_upper[32]; + char tocode_upper[32]; + char *fromcode_upper_end; + char *tocode_upper_end; + +#if REPLACE_ICONV_UTF + /* Special handling of conversion between UTF-8 and UTF-{16,32}{BE,LE}. + Do this here, before calling the real iconv_open(), because OSF/1 5.1 + iconv() to these encoding inserts a BOM, which is wrong. + We do not need to handle conversion between arbitrary encodings and + UTF-{16,32}{BE,LE}, because the 'striconveh' module implements two-step + conversion through UTF-8. + The _ICONV_* constants are chosen to be disjoint from any iconv_t + returned by the system's iconv_open() functions. Recall that iconv_t + is a scalar type. */ + if (c_toupper (fromcode[0]) == 'U' + && c_toupper (fromcode[1]) == 'T' + && c_toupper (fromcode[2]) == 'F' + && fromcode[3] == '-') + { + if (c_toupper (tocode[0]) == 'U' + && c_toupper (tocode[1]) == 'T' + && c_toupper (tocode[2]) == 'F' + && tocode[3] == '-') + { + if (strcmp (fromcode + 4, "8") == 0) + { + if (c_strcasecmp (tocode + 4, "16BE") == 0) + return _ICONV_UTF8_UTF16BE; + if (c_strcasecmp (tocode + 4, "16LE") == 0) + return _ICONV_UTF8_UTF16LE; + if (c_strcasecmp (tocode + 4, "32BE") == 0) + return _ICONV_UTF8_UTF32BE; + if (c_strcasecmp (tocode + 4, "32LE") == 0) + return _ICONV_UTF8_UTF32LE; + } + else if (strcmp (tocode + 4, "8") == 0) + { + if (c_strcasecmp (fromcode + 4, "16BE") == 0) + return _ICONV_UTF16BE_UTF8; + if (c_strcasecmp (fromcode + 4, "16LE") == 0) + return _ICONV_UTF16LE_UTF8; + if (c_strcasecmp (fromcode + 4, "32BE") == 0) + return _ICONV_UTF32BE_UTF8; + if (c_strcasecmp (fromcode + 4, "32LE") == 0) + return _ICONV_UTF32LE_UTF8; + } + } + } +#endif + + /* Do *not* add special support for 8-bit encodings like ASCII or ISO-8859-1 + here. This would lead to programs that work in some locales (such as the + "C" or "en_US" locales) but do not work in East Asian locales. It is + better if programmers make their programs depend on GNU libiconv (except + on glibc systems), e.g. by using the AM_ICONV macro and documenting the + dependency in an INSTALL or DEPENDENCIES file. */ + + /* Try with the original names first. + This covers the case when fromcode or tocode is a lowercase encoding name + that is understood by the system's iconv_open but not listed in our + mappings table. */ + { + iconv_t cd = iconv_open (tocode, fromcode); + if (cd != (iconv_t)(-1)) + return cd; + } + + /* Convert the encodings to upper case, because + 1. in the arguments of iconv_open() on AIX, HP-UX, and OSF/1 the case + matters, + 2. it makes searching in the table faster. */ + { + const char *p = fromcode; + char *q = fromcode_upper; + while ((*q = c_toupper (*p)) != '\0') + { + p++; + q++; + if (q == &fromcode_upper[SIZEOF (fromcode_upper)]) + { + errno = EINVAL; + return (iconv_t)(-1); + } + } + fromcode_upper_end = q; + } + + { + const char *p = tocode; + char *q = tocode_upper; + while ((*q = c_toupper (*p)) != '\0') + { + p++; + q++; + if (q == &tocode_upper[SIZEOF (tocode_upper)]) + { + errno = EINVAL; + return (iconv_t)(-1); + } + } + tocode_upper_end = q; + } + +#ifdef ICONV_FLAVOR + /* Apply the mappings. */ + { + const struct mapping *m = + mapping_lookup (fromcode_upper, fromcode_upper_end - fromcode_upper); + + fromcode = (m != NULL ? m->vendor_name : fromcode_upper); + } + { + const struct mapping *m = + mapping_lookup (tocode_upper, tocode_upper_end - tocode_upper); + + tocode = (m != NULL ? m->vendor_name : tocode_upper); + } +#else + fromcode = fromcode_upper; + tocode = tocode_upper; +#endif + + return iconv_open (tocode, fromcode); +} |