/*------------------------------------------------------------------ * wctomb_s.c * * September 2017, Reini Urban * * Copyright (c) 2017 by Reini Urban * All rights reserved. * * Permission is hereby granted, free of charge, to any person * obtaining a copy of this software and associated documentation * files (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, * copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following * conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. *------------------------------------------------------------------ */ #ifdef FOR_DOXYGEN #include "safe_str_lib.h" #else #include "safeclib_private.h" #endif #if (defined(TEST_MSVCRT) && defined(HAVE_WCSTOMBS_S)) || !defined(HAVE_WCHAR_H) #else #if defined(__CYGWIN__) && defined(__x86_64) #define wctomb(dest, wc) wcrtomb((dest), (wc), &st) #endif /** * @def wctomb_s(retvalp,dest,dmax,wc) * @brief * The \c wctomb_s function converts a single * wide character to its narrow multibyte representation from the current * LC_CTYPE locale. * If \c dest is not null, the converted multibyte characters are * stored in \c dest. Max. \c MB_CUR_MAX will be written to \c dest. * * If \c dest is a null pointer, the call is equivalent to * wcrtomb_s(&retval, buf, sizeof buf, L'\0', ps) with * internal variables \c retval and \c buf (whose size is greater than * \c MB_CUR_MAX). * * If the environment macro __STDC_ISO_10646__ is defined, the * values of type wchar_t are the same as the short identifiers of * the characters in the Unicode required set (typically UTF-32 * encoding); otherwise, it is implementation-defined. In any case, * the multibyte character encoding used by this function is * specified by the currently active C locale. * * If the environment macro __STDC_MB_MIGHT_NEQ_WC__ is defined, * then for members of the basic character set multibyte-character * encoding might not equal wide-character encoding * (non-ASCII-based systems, such as EBCDIC-based systems, may use * Unicode for their wide character encoding and still be * conforming). ASCII-based systems with __STDC_ISO_10646__ defined * leave __STDC_MB_MIGHT_NEQ_WC__ undefined. * * With SAFECLIB_STR_NULL_SLACK defined all elements following the * terminating null character (if any) written in the array of dmax * characters pointed to by dest are nulled. Also in the error cases for * ESNOSPC and EILSEQ. * * @remark SPECIFIED IN * * C11 standard (ISO/IEC 9899:2011): * K.3.6.4.1 The wctomb_s function (p: 610-611) * http://en.cppreference.com/w/c/string/multibyte/wctomb * * ISO/IEC TR 24731, Programming languages, environments * and system software interfaces, Extensions to the C Library, * Part I: Bounds-checking interfaces * * @param[out] retvalp pointer to a \c size_t object where the result will be * stored * @param[out] dest pointer to bytes where the result will be stored * @param[in] dmax restricted maximum length of \c dest * @param[in] wc the wide character to convert * * @pre retvalp shall not be a null pointer. * @pre dmax shall not be greater than \c RSIZE_MAX_STR and size of dest * (unless dest is null). * @pre dmax shall not equal zero (unless dest is null). * @pre dmax must be zero if dest is null. * * @note C11 uses RSIZE_MAX, not RSIZE_MAX_STR. * * @return Returns zero on success and non-zero on failure, in which * case, \c dest[0] is set to '\0' (unless dest is null or dmax is * invalid) and \c *retvalp is set to (size_t)-1 (unless retvalp is null). * * @retval EOK on successful conversion. * @retval ESNULLP when retvalp is a NULL pointer * @retval ESZEROL when dmax = 0, unless dest is NULL * @retval ESLEMAX when dmax > RSIZE_MAX_STR, unless dest is NULL * @retval EOVERFLOW when dmax > size of dest (optionally, when the compiler * knows the object_size statically) * @retval ESLEWRNG when dmax != size of dest and --enable-error-dmax * @retval ESNOSPC when dmax is smaller than the number of required bytes * @retval EILSEQ if returned by wctomb() * * @see * wcrtomb_s() */ #ifdef FOR_DOXYGEN errno_t wctomb_s(int *restrict retvalp, char *restrict dest, rsize_t dmax, wchar_t wc) #else EXPORT errno_t _wctomb_s_chk(int *restrict retvalp, char *restrict dest, rsize_t dmax, wchar_t wc, const size_t destbos) #endif { int len; errno_t rc; #if defined(__CYGWIN__) && defined(__x86_64) mbstate_t st; #endif CHK_SRC_NULL("wctomb_s", retvalp) /* GLIBC asserts with len=0 and wrong state. darwin and musl is fine. */ if (dest) { CHK_DMAX_ZERO("wctomb_s") if (destbos == BOS_UNKNOWN) { CHK_DMAX_MAX("wctomb_s", RSIZE_MAX_WSTR) BND_CHK_PTR_BOUNDS(dest, dmax); } else { CHK_DEST_OVR("wctomb_s", destbos) } } else { if (unlikely(dmax != 0)) { invoke_safe_str_constraint_handler("wctomb_s" ": dmax is not 0", (void *)dest, ESNULLP); return RCNEGATE(ESNULLP); } } len = *retvalp = wctomb(dest, wc); if (likely(len > 0 && (rsize_t)len < dmax)) { #ifdef SAFECLIB_STR_NULL_SLACK if (dest) memset(&dest[len], 0, dmax - len); #endif rc = EOK; } else { /* errno is usually EILSEQ */ rc = (len > 0) ? ESNOSPC : errno; if (dest) { /* the entire src must have been copied, if not reset dest * to null the string. (only with SAFECLIB_STR_NULL_SLACK) */ handle_error(dest, dmax, rc == ESNOSPC ? "wctomb_s: not enough space for src" : "wctomb_s: illegal sequence", rc); } } return RCNEGATE(rc); } #endif /* HAVE_WCHAR_H or !TEST_MSVCRT */