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/*
* Copyright (C) 2017 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <stdio.h>
#include <wchar.h>
#include "UniquePtr.h"
namespace {
const size_t MBS_FAILURE = static_cast<size_t>(-1);
}
int swprintf(wchar_t* wcs, size_t maxlen, const wchar_t* format, ...) {
va_list ap;
va_start(ap, format);
int result = vswprintf(wcs, maxlen, format, ap);
va_end(ap);
return result;
}
int vswprintf(wchar_t* wcs, size_t maxlen, const wchar_t* fmt, va_list ap) {
mbstate_t mbstate;
memset(&mbstate, 0, sizeof(mbstate));
// At most, each wide character (UTF-32) can be expanded to four narrow
// characters (UTF-8).
const size_t max_mb_len = maxlen * 4;
const size_t mb_fmt_len = wcslen(fmt) * 4 + 1;
UniquePtr<char[]> mbfmt(new char[mb_fmt_len]);
if (wcsrtombs(mbfmt.get(), &fmt, mb_fmt_len, &mbstate) == MBS_FAILURE) {
return -1;
}
UniquePtr<char[]> mbs(new char[max_mb_len]);
int nprinted = vsnprintf(mbs.get(), max_mb_len, mbfmt.get(), ap);
if (nprinted == -1) {
return -1;
}
const char* mbsp = mbs.get();
if (mbsrtowcs(wcs, &mbsp, maxlen, &mbstate) == MBS_FAILURE) {
return -1;
}
// Can't use return value from vsnprintf because that number is in narrow
// characters, not wide characters.
int result = wcslen(wcs);
// swprintf differs from snprintf in that it returns -1 if the output was
// truncated.
//
// Truncation can occur in two places:
// 1) vsnprintf truncated, in which case the return value is greater than the
// length we passed.
// 2) Since the char buffer we pass to vsnprintf might be oversized, that
// might not truncate while mbsrtowcs will. In this case, mbsp will point
// to the next unconverted character instead of nullptr.
if (nprinted >= max_mb_len || mbsp != nullptr) {
return -1;
}
return result;
}
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