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/*
* Copyright (C) 2014 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 <errno.h>
#include <uchar.h>
#include <wchar.h>
#include "private/bionic_mbstate.h"
size_t c32rtomb(char* s, char32_t c32, mbstate_t* ps) {
static mbstate_t __private_state;
mbstate_t* state = (ps == nullptr) ? &__private_state : ps;
if (s == nullptr) {
// Equivalent to c32rtomb(buf, U'\0', ps).
return mbstate_reset_and_return(1, state);
}
// POSIX states that if char32_t is a null wide character, a null byte shall
// be stored, preceded by any shift sequence needed to restore the initial
// shift state. Since shift states are not supported, only the null byte is
// stored.
if (c32 == U'\0') {
*s = '\0';
return mbstate_reset_and_return(1, state);
}
if (!mbsinit(state)) {
return mbstate_reset_and_return_illegal(EILSEQ, state);
}
if ((c32 & ~0x7f) == 0) {
// Fast path for plain ASCII characters.
*s = c32;
return 1;
}
// Determine the number of octets needed to represent this character.
// We always output the shortest sequence possible. Also specify the
// first few bits of the first octet, which contains the information
// about the sequence length.
uint8_t lead;
size_t length;
if ((c32 & ~0x7f) == 0) {
lead = 0;
length = 1;
} else if ((c32 & ~0x7ff) == 0) {
lead = 0xc0;
length = 2;
} else if ((c32 & ~0xffff) == 0) {
lead = 0xe0;
length = 3;
} else if ((c32 & ~0x1fffff) == 0) {
lead = 0xf0;
length = 4;
} else {
errno = EILSEQ;
return __MB_ERR_ILLEGAL_SEQUENCE;
}
// Output the octets representing the character in chunks
// of 6 bits, least significant last. The first octet is
// a special case because it contains the sequence length
// information.
for (size_t i = length - 1; i > 0; i--) {
s[i] = (c32 & 0x3f) | 0x80;
c32 >>= 6;
}
*s = (c32 & 0xff) | lead;
return length;
}
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