/*
* Copyright (C) 2005 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "unicode"
#include <android-base/macros.h>
#include <limits.h>
#include <utils/Unicode.h>
#include <log/log.h>
#if defined(_WIN32)
# undef nhtol
# undef htonl
# undef nhtos
# undef htons
# define ntohl(x) ( ((x) << 24) | (((x) >> 24) & 255) | (((x) << 8) & 0xff0000) | (((x) >> 8) & 0xff00) )
# define htonl(x) ntohl(x)
# define ntohs(x) ( (((x) << 8) & 0xff00) | (((x) >> 8) & 255) )
# define htons(x) ntohs(x)
#else
# include <netinet/in.h>
#endif
extern "C" {
static const char32_t kByteMask = 0x000000BF;
static const char32_t kByteMark = 0x00000080;
// Surrogates aren't valid for UTF-32 characters, so define some
// constants that will let us screen them out.
static const char32_t kUnicodeSurrogateHighStart = 0x0000D800;
// Unused, here for completeness:
// static const char32_t kUnicodeSurrogateHighEnd = 0x0000DBFF;
// static const char32_t kUnicodeSurrogateLowStart = 0x0000DC00;
static const char32_t kUnicodeSurrogateLowEnd = 0x0000DFFF;
static const char32_t kUnicodeSurrogateStart = kUnicodeSurrogateHighStart;
static const char32_t kUnicodeSurrogateEnd = kUnicodeSurrogateLowEnd;
static const char32_t kUnicodeMaxCodepoint = 0x0010FFFF;
// Mask used to set appropriate bits in first byte of UTF-8 sequence,
// indexed by number of bytes in the sequence.
// 0xxxxxxx
// -> (00-7f) 7bit. Bit mask for the first byte is 0x00000000
// 110yyyyx 10xxxxxx
// -> (c0-df)(80-bf) 11bit. Bit mask is 0x000000C0
// 1110yyyy 10yxxxxx 10xxxxxx
// -> (e0-ef)(80-bf)(80-bf) 16bit. Bit mask is 0x000000E0
// 11110yyy 10yyxxxx 10xxxxxx 10xxxxxx
// -> (f0-f7)(80-bf)(80-bf)(80-bf) 21bit. Bit mask is 0x000000F0
static const char32_t kFirstByteMark[] = {
0x00000000, 0x00000000, 0x000000C0, 0x000000E0, 0x000000F0
};
// --------------------------------------------------------------------------
// UTF-32
// --------------------------------------------------------------------------
/**
* Return number of UTF-8 bytes required for the character. If the character
* is invalid, return size of 0.
*/
static inline size_t utf32_codepoint_utf8_length(char32_t srcChar)
{
// Figure out how many bytes the result will require.
if (srcChar < 0x00000080) {
return 1;
} else if (srcChar < 0x00000800) {
return 2;
} else if (srcChar < 0x00010000) {
if ((srcChar < kUnicodeSurrogateStart) || (srcChar > kUnicodeSurrogateEnd)) {
return 3;
} else {
// Surrogates are invalid UTF-32 characters.
return 0;
}
}
// Max code point for Unicode is 0x0010FFFF.
else if (srcChar <= kUnicodeMaxCodepoint) {
return 4;
} else {
// Invalid UTF-32 character.
return 0;
}
}
// Write out the source character to <dstP>.
static inline void utf32_codepoint_to_utf8(uint8_t* dstP, char32_t srcChar, size_t bytes)
{
dstP += bytes;
switch (bytes)
{ /* note: everything falls through. */
case 4: *--dstP = (uint8_t)((srcChar | kByteMark) & kByteMask); srcChar >>= 6;
FALLTHROUGH_INTENDED;
case 3: *--dstP = (uint8_t)((srcChar | kByteMark) & kByteMask); srcChar >>= 6;
FALLTHROUGH_INTENDED;
case 2: *--dstP = (uint8_t)((srcChar | kByteMark) & kByteMask); srcChar >>= 6;
FALLTHROUGH_INTENDED;
case 1: *--dstP = (uint8_t)(srcChar | kFirstByteMark[bytes]);
}
}
size_t strlen32(const char32_t *s)
{
const char32_t *ss = s;
while ( *ss )
ss++;
return ss-s;
}
size_t strnlen32(const char32_t *s, size_t maxlen)
{
const char32_t *ss = s;
while ((maxlen > 0) && *ss) {
ss++;
maxlen--;
}
return ss-s;
}
static inline int32_t utf32_at_internal(const char* cur, size_t *num_read)
{
const char first_char = *cur;
if ((first_char & 0x80) == 0) { // ASCII
*num_read = 1;
return *cur;
}
cur++;
char32_t mask, to_ignore_mask;
size_t num_to_read = 0;
char32_t utf32 = first_char;
for (num_to_read = 1, mask = 0x40, to_ignore_mask = 0xFFFFFF80;
(first_char & mask);
num_to_read++, to_ignore_mask |= mask, mask >>= 1) {
// 0x3F == 00111111
utf32 = (utf32 << 6) + (*cur++ & 0x3F);
}
to_ignore_mask |= mask;
utf32 &= ~(to_ignore_mask << (6 * (num_to_read - 1)));
*num_read = num_to_read;
return static_cast<int32_t>(utf32);
}
int32_t utf32_from_utf8_at(const char *src, size_t src_len, size_t index, size_t *next_index)
{
if (index >= src_len) {
return -1;
}
size_t dummy_index;
if (next_index == nullptr) {
next_index = &dummy_index;
}
size_t num_read;
int32_t ret = utf32_at_internal(src + index, &num_read);
if (ret >= 0) {
*next_index = index + num_read;
}
return ret;
}
ssize_t utf32_to_utf8_length(const char32_t *src, size_t src_len)
{
if (src == nullptr || src_len == 0) {
return -1;
}
size_t ret = 0;
const char32_t *end = src + src_len;
while (src < end) {
size_t char_len = utf32_codepoint_utf8_length(*src++);
if (SSIZE_MAX - char_len < ret) {
// If this happens, we would overflow the ssize_t type when
// returning from this function, so we cannot express how
// long this string is in an ssize_t.
android_errorWriteLog(0x534e4554, "37723026");
return -1;
}
ret += char_len;
}
return ret;
}
void utf32_to_utf8(const char32_t* src, size_t src_len, char* dst, size_t dst_len)
{
if (src == nullptr || src_len == 0 || dst == nullptr) {
return;
}
const char32_t *cur_utf32 = src;
const char32_t *end_utf32 = src + src_len;
char *cur = dst;
while (cur_utf32 < end_utf32) {
size_t len = utf32_codepoint_utf8_length(*cur_utf32);
LOG_ALWAYS_FATAL_IF(dst_len < len, "%zu < %zu", dst_len, len);
utf32_codepoint_to_utf8((uint8_t *)cur, *cur_utf32++, len);
cur += len;
dst_len -= len;
}
LOG_ALWAYS_FATAL_IF(dst_len < 1, "dst_len < 1: %zu < 1", dst_len);
*cur = '\0';
}
// --------------------------------------------------------------------------
// UTF-16
// --------------------------------------------------------------------------
int strcmp16(const char16_t *s1, const char16_t *s2)
{
char16_t ch;
int d = 0;
while ( 1 ) {
d = (int)(ch = *s1++) - (int)*s2++;
if ( d || !ch )
break;
}
return d;
}
int strncmp16(const char16_t *s1, const char16_t *s2, size_t n)
{
char16_t ch;
int d = 0;
if (n == 0) {
return 0;
}
do {
d = (int)(ch = *s1++) - (int)*s2++;
if ( d || !ch ) {
break;
}
} while (--n);
return d;
}
char16_t *strcpy16(char16_t *dst, const char16_t *src)
{
char16_t *q = dst;
const char16_t *p = src;
char16_t ch;
do {
*q++ = ch = *p++;
} while ( ch );
return dst;
}
size_t strlen16(const char16_t *s)
{
const char16_t *ss = s;
while ( *ss )
ss++;
return ss-s;
}
size_t strnlen16(const char16_t *s, size_t maxlen)
{
const char16_t *ss = s;
/* Important: the maxlen test must precede the reference through ss;
since the byte beyond the maximum may segfault */
while ((maxlen > 0) && *ss) {
ss++;
maxlen--;
}
return ss-s;
}
char16_t* strstr16(const char16_t* src, const char16_t* target)
{
const char16_t needle = *target;
if (needle == '\0') return (char16_t*)src;
const size_t target_len = strlen16(++target);
do {
do {
if (*src == '\0') {
return nullptr;
}
} while (*src++ != needle);
} while (strncmp16(src, target, target_len) != 0);
src--;
return (char16_t*)src;
}
int strzcmp16(const char16_t *s1, size_t n1, const char16_t *s2, size_t n2)
{
const char16_t* e1 = s1+n1;
const char16_t* e2 = s2+n2;
while (s1 < e1 && s2 < e2) {
const int d = (int)*s1++ - (int)*s2++;
if (d) {
return d;
}
}
return n1 < n2
? (0 - (int)*s2)
: (n1 > n2
? ((int)*s1 - 0)
: 0);
}
void utf16_to_utf8(const char16_t* src, size_t src_len, char* dst, size_t dst_len)
{
if (src == nullptr || src_len == 0 || dst == nullptr) {
return;
}
const char16_t* cur_utf16 = src;
const char16_t* const end_utf16 = src + src_len;
char *cur = dst;
while (cur_utf16 < end_utf16) {
char32_t utf32;
// surrogate pairs
if((*cur_utf16 & 0xFC00) == 0xD800 && (cur_utf16 + 1) < end_utf16
&& (*(cur_utf16 + 1) & 0xFC00) == 0xDC00) {
utf32 = (*cur_utf16++ - 0xD800) << 10;
utf32 |= *cur_utf16++ - 0xDC00;
utf32 += 0x10000;
} else {
utf32 = (char32_t) *cur_utf16++;
}
const size_t len = utf32_codepoint_utf8_length(utf32);
LOG_ALWAYS_FATAL_IF(dst_len < len, "%zu < %zu", dst_len, len);
utf32_codepoint_to_utf8((uint8_t*)cur, utf32, len);
cur += len;
dst_len -= len;
}
LOG_ALWAYS_FATAL_IF(dst_len < 1, "%zu < 1", dst_len);
*cur = '\0';
}
// --------------------------------------------------------------------------
// UTF-8
// --------------------------------------------------------------------------
ssize_t utf8_length(const char *src)
{
const char *cur = src;
size_t ret = 0;
while (*cur != '\0') {
const char first_char = *cur++;
if ((first_char & 0x80) == 0) { // ASCII
ret += 1;
continue;
}
// (UTF-8's character must not be like 10xxxxxx,
// but 110xxxxx, 1110xxxx, ... or 1111110x)
if ((first_char & 0x40) == 0) {
return -1;
}
int32_t mask, to_ignore_mask;
size_t num_to_read = 0;
char32_t utf32 = 0;
for (num_to_read = 1, mask = 0x40, to_ignore_mask = 0x80;
num_to_read < 5 && (first_char & mask);
num_to_read++, to_ignore_mask |= mask, mask >>= 1) {
if ((*cur & 0xC0) != 0x80) { // must be 10xxxxxx
return -1;
}
// 0x3F == 00111111
utf32 = (utf32 << 6) + (*cur++ & 0x3F);
}
// "first_char" must be (110xxxxx - 11110xxx)
if (num_to_read == 5) {
return -1;
}
to_ignore_mask |= mask;
utf32 |= ((~to_ignore_mask) & first_char) << (6 * (num_to_read - 1));
if (utf32 > kUnicodeMaxCodepoint) {
return -1;
}
ret += num_to_read;
}
return ret;
}
ssize_t utf16_to_utf8_length(const char16_t *src, size_t src_len)
{
if (src == nullptr || src_len == 0) {
return -1;
}
size_t ret = 0;
const char16_t* const end = src + src_len;
while (src < end) {
size_t char_len;
if ((*src & 0xFC00) == 0xD800 && (src + 1) < end
&& (*(src + 1) & 0xFC00) == 0xDC00) {
// surrogate pairs are always 4 bytes.
char_len = 4;
src += 2;
} else {
char_len = utf32_codepoint_utf8_length((char32_t)*src++);
}
if (SSIZE_MAX - char_len < ret) {
// If this happens, we would overflow the ssize_t type when
// returning from this function, so we cannot express how
// long this string is in an ssize_t.
android_errorWriteLog(0x534e4554, "37723026");
return -1;
}
ret += char_len;
}
return ret;
}
/**
* Returns 1-4 based on the number of leading bits.
*
* 1111 -> 4
* 1110 -> 3
* 110x -> 2
* 10xx -> 1
* 0xxx -> 1
*/
static inline size_t utf8_codepoint_len(uint8_t ch)
{
return ((0xe5000000 >> ((ch >> 3) & 0x1e)) & 3) + 1;
}
static inline void utf8_shift_and_mask(uint32_t* codePoint, const uint8_t byte)
{
*codePoint <<= 6;
*codePoint |= 0x3F & byte;
}
size_t utf8_to_utf32_length(const char *src, size_t src_len)
{
if (src == nullptr || src_len == 0) {
return 0;
}
size_t ret = 0;
const char* cur;
const char* end;
size_t num_to_skip;
for (cur = src, end = src + src_len, num_to_skip = 1;
cur < end;
cur += num_to_skip, ret++) {
const char first_char = *cur;
num_to_skip = 1;
if ((first_char & 0x80) == 0) { // ASCII
continue;
}
int32_t mask;
for (mask = 0x40; (first_char & mask); num_to_skip++, mask >>= 1) {
}
}
return ret;
}
void utf8_to_utf32(const char* src, size_t src_len, char32_t* dst)
{
if (src == nullptr || src_len == 0 || dst == nullptr) {
return;
}
const char* cur = src;
const char* const end = src + src_len;
char32_t* cur_utf32 = dst;
while (cur < end) {
size_t num_read;
*cur_utf32++ = static_cast<char32_t>(utf32_at_internal(cur, &num_read));
cur += num_read;
}
*cur_utf32 = 0;
}
static inline uint32_t utf8_to_utf32_codepoint(const uint8_t *src, size_t length)
{
uint32_t unicode;
switch (length)
{
case 1:
return src[0];
case 2:
unicode = src[0] & 0x1f;
utf8_shift_and_mask(&unicode, src[1]);
return unicode;
case 3:
unicode = src[0] & 0x0f;
utf8_shift_and_mask(&unicode, src[1]);
utf8_shift_and_mask(&unicode, src[2]);
return unicode;
case 4:
unicode = src[0] & 0x07;
utf8_shift_and_mask(&unicode, src[1]);
utf8_shift_and_mask(&unicode, src[2]);
utf8_shift_and_mask(&unicode, src[3]);
return unicode;
default:
return 0xffff;
}
//printf("Char at %p: len=%d, utf-16=%p\n", src, length, (void*)result);
}
ssize_t utf8_to_utf16_length(const uint8_t* u8str, size_t u8len, bool overreadIsFatal)
{
const uint8_t* const u8end = u8str + u8len;
const uint8_t* u8cur = u8str;
/* Validate that the UTF-8 is the correct len */
size_t u16measuredLen = 0;
while (u8cur < u8end) {
u16measuredLen++;
int u8charLen = utf8_codepoint_len(*u8cur);
// Malformed utf8, some characters are beyond the end.
// Cases:
// If u8charLen == 1, this becomes u8cur >= u8end, which cannot happen as u8cur < u8end,
// then this condition fail and we continue, as expected.
// If u8charLen == 2, this becomes u8cur + 1 >= u8end, which fails only if
// u8cur == u8end - 1, that is, there was only one remaining character to read but we need
// 2 of them. This condition holds and we return -1, as expected.
if (u8cur + u8charLen - 1 >= u8end) {
if (overreadIsFatal) {
LOG_ALWAYS_FATAL("Attempt to overread computing length of utf8 string");
} else {
return -1;
}
}
uint32_t codepoint = utf8_to_utf32_codepoint(u8cur, u8charLen);
if (codepoint > 0xFFFF) u16measuredLen++; // this will be a surrogate pair in utf16
u8cur += u8charLen;
}
/**
* Make sure that we ended where we thought we would and the output UTF-16
* will be exactly how long we were told it would be.
*/
if (u8cur != u8end) {
return -1;
}
return u16measuredLen;
}
char16_t* utf8_to_utf16(const uint8_t* u8str, size_t u8len, char16_t* u16str, size_t u16len) {
// A value > SSIZE_MAX is probably a negative value returned as an error and casted.
LOG_ALWAYS_FATAL_IF(u16len == 0 || u16len > SSIZE_MAX, "u16len is %zu", u16len);
char16_t* end = utf8_to_utf16_no_null_terminator(u8str, u8len, u16str, u16len - 1);
*end = 0;
return end;
}
char16_t* utf8_to_utf16_no_null_terminator(
const uint8_t* src, size_t srcLen, char16_t* dst, size_t dstLen) {
if (dstLen == 0) {
return dst;
}
// A value > SSIZE_MAX is probably a negative value returned as an error and casted.
LOG_ALWAYS_FATAL_IF(dstLen > SSIZE_MAX, "dstLen is %zu", dstLen);
const uint8_t* const u8end = src + srcLen;
const uint8_t* u8cur = src;
const char16_t* const u16end = dst + dstLen;
char16_t* u16cur = dst;
while (u8cur < u8end && u16cur < u16end) {
size_t u8len = utf8_codepoint_len(*u8cur);
uint32_t codepoint = utf8_to_utf32_codepoint(u8cur, u8len);
// Convert the UTF32 codepoint to one or more UTF16 codepoints
if (codepoint <= 0xFFFF) {
// Single UTF16 character
*u16cur++ = (char16_t) codepoint;
} else {
// Multiple UTF16 characters with surrogates
codepoint = codepoint - 0x10000;
*u16cur++ = (char16_t) ((codepoint >> 10) + 0xD800);
if (u16cur >= u16end) {
// Ooops... not enough room for this surrogate pair.
return u16cur-1;
}
*u16cur++ = (char16_t) ((codepoint & 0x3FF) + 0xDC00);
}
u8cur += u8len;
}
return u16cur;
}
}