// Scintilla source code edit control
/** @file UniConversion.cxx
** Functions to handle UTF-8 and UTF-16 strings.
**/
// Copyright 1998-2001 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.
#include <stdlib.h>
#include "UniConversion.h"
enum { SURROGATE_LEAD_FIRST = 0xD800 };
enum { SURROGATE_TRAIL_FIRST = 0xDC00 };
enum { SURROGATE_TRAIL_LAST = 0xDFFF };
unsigned int UTF8Length(const wchar_t *uptr, unsigned int tlen) {
unsigned int len = 0;
for (unsigned int i = 0; i < tlen && uptr[i];) {
unsigned int uch = uptr[i];
if (uch < 0x80) {
len++;
} else if (uch < 0x800) {
len += 2;
} else if ((uch >= SURROGATE_LEAD_FIRST) &&
(uch <= SURROGATE_TRAIL_LAST)) {
len += 4;
i++;
} else {
len += 3;
}
i++;
}
return len;
}
void UTF8FromUTF16(const wchar_t *uptr, unsigned int tlen, char *putf, unsigned int len) {
int k = 0;
for (unsigned int i = 0; i < tlen && uptr[i];) {
unsigned int uch = uptr[i];
if (uch < 0x80) {
putf[k++] = static_cast<char>(uch);
} else if (uch < 0x800) {
putf[k++] = static_cast<char>(0xC0 | (uch >> 6));
putf[k++] = static_cast<char>(0x80 | (uch & 0x3f));
} else if ((uch >= SURROGATE_LEAD_FIRST) &&
(uch <= SURROGATE_TRAIL_LAST)) {
// Half a surrogate pair
i++;
unsigned int xch = 0x10000 + ((uch & 0x3ff) << 10) + (uptr[i] & 0x3ff);
putf[k++] = static_cast<char>(0xF0 | (xch >> 18));
putf[k++] = static_cast<char>(0x80 | ((xch >> 12) & 0x3f));
putf[k++] = static_cast<char>(0x80 | ((xch >> 6) & 0x3f));
putf[k++] = static_cast<char>(0x80 | (xch & 0x3f));
} else {
putf[k++] = static_cast<char>(0xE0 | (uch >> 12));
putf[k++] = static_cast<char>(0x80 | ((uch >> 6) & 0x3f));
putf[k++] = static_cast<char>(0x80 | (uch & 0x3f));
}
i++;
}
putf[len] = '\0';
}
unsigned int UTF8CharLength(unsigned char ch) {
if (ch < 0x80) {
return 1;
} else if (ch < 0x80 + 0x40 + 0x20) {
return 2;
} else if (ch < 0x80 + 0x40 + 0x20 + 0x10) {
return 3;
} else {
return 4;
}
}
unsigned int UTF16Length(const char *s, unsigned int len) {
unsigned int ulen = 0;
unsigned int charLen;
for (unsigned int i=0; i<len;) {
unsigned char ch = static_cast<unsigned char>(s[i]);
if (ch < 0x80) {
charLen = 1;
} else if (ch < 0x80 + 0x40 + 0x20) {
charLen = 2;
} else if (ch < 0x80 + 0x40 + 0x20 + 0x10) {
charLen = 3;
} else {
charLen = 4;
ulen++;
}
i += charLen;
ulen++;
}
return ulen;
}
unsigned int UTF16FromUTF8(const char *s, unsigned int len, wchar_t *tbuf, unsigned int tlen) {
unsigned int ui=0;
const unsigned char *us = reinterpret_cast<const unsigned char *>(s);
unsigned int i=0;
while ((i<len) && (ui<tlen)) {
unsigned char ch = us[i++];
if (ch < 0x80) {
tbuf[ui] = ch;
} else if (ch < 0x80 + 0x40 + 0x20) {
tbuf[ui] = static_cast<wchar_t>((ch & 0x1F) << 6);
ch = us[i++];
tbuf[ui] = static_cast<wchar_t>(tbuf[ui] + (ch & 0x7F));
} else if (ch < 0x80 + 0x40 + 0x20 + 0x10) {
tbuf[ui] = static_cast<wchar_t>((ch & 0xF) << 12);
ch = us[i++];
tbuf[ui] = static_cast<wchar_t>(tbuf[ui] + ((ch & 0x7F) << 6));
ch = us[i++];
tbuf[ui] = static_cast<wchar_t>(tbuf[ui] + (ch & 0x7F));
} else {
// Outside the BMP so need two surrogates
int val = (ch & 0x7) << 18;
ch = us[i++];
val += (ch & 0x3F) << 12;
ch = us[i++];
val += (ch & 0x3F) << 6;
ch = us[i++];
val += (ch & 0x3F);
tbuf[ui] = static_cast<wchar_t>(((val - 0x10000) >> 10) + SURROGATE_LEAD_FIRST);
ui++;
tbuf[ui] = static_cast<wchar_t>((val & 0x3ff) + SURROGATE_TRAIL_FIRST);
}
ui++;
}
return ui;
}
int UTF8BytesOfLead[256];
static bool initialisedBytesOfLead = false;
static int BytesFromLead(int leadByte) {
if (leadByte < 0xC2) {
// Single byte or invalid
return 1;
} else if (leadByte < 0xE0) {
return 2;
} else if (leadByte < 0xF0) {
return 3;
} else if (leadByte < 0xF5) {
return 4;
} else {
// Characters longer than 4 bytes not possible in current UTF-8
return 1;
}
}
void UTF8BytesOfLeadInitialise() {
if (!initialisedBytesOfLead) {
for (int i=0;i<256;i++) {
UTF8BytesOfLead[i] = BytesFromLead(i);
}
initialisedBytesOfLead = true;
}
}
// Return both the width of the first character in the string and a status
// saying whether it is valid or invalid.
// Most invalid sequences return a width of 1 so are treated as isolated bytes but
// the non-characters *FFFE, *FFFF and FDD0 .. FDEF return 3 or 4 as they can be
// reasonably treated as code points in some circumstances. They will, however,
// not have associated glyphs.
int UTF8Classify(const unsigned char *us, int len) {
// For the rules: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
if (*us < 0x80) {
// Single bytes easy
return 1;
} else if (*us > 0xf4) {
// Characters longer than 4 bytes not possible in current UTF-8
return UTF8MaskInvalid | 1;
} else if (*us >= 0xf0) {
// 4 bytes
if (len < 4)
return UTF8MaskInvalid | 1;
if (UTF8IsTrailByte(us[1]) && UTF8IsTrailByte(us[2]) && UTF8IsTrailByte(us[3])) {
if (((us[1] & 0xf) == 0xf) && (us[2] == 0xbf) && ((us[3] == 0xbe) || (us[3] == 0xbf))) {
// *FFFE or *FFFF non-character
return UTF8MaskInvalid | 4;
}
if (*us == 0xf4) {
// Check if encoding a value beyond the last Unicode character 10FFFF
if (us[1] > 0x8f) {
return UTF8MaskInvalid | 1;
} else if (us[1] == 0x8f) {
if (us[2] > 0xbf) {
return UTF8MaskInvalid | 1;
} else if (us[2] == 0xbf) {
if (us[3] > 0xbf) {
return UTF8MaskInvalid | 1;
}
}
}
} else if ((*us == 0xf0) && ((us[1] & 0xf0) == 0x80)) {
// Overlong
return UTF8MaskInvalid | 1;
}
return 4;
} else {
return UTF8MaskInvalid | 1;
}
} else if (*us >= 0xe0) {
// 3 bytes
if (len < 3)
return UTF8MaskInvalid | 1;
if (UTF8IsTrailByte(us[1]) && UTF8IsTrailByte(us[2])) {
if ((*us == 0xe0) && ((us[1] & 0xe0) == 0x80)) {
// Overlong
return UTF8MaskInvalid | 1;
}
if ((*us == 0xed) && ((us[1] & 0xe0) == 0xa0)) {
// Surrogate
return UTF8MaskInvalid | 1;
}
if ((*us == 0xef) && (us[1] == 0xbf) && (us[2] == 0xbe)) {
// U+FFFE non-character - 3 bytes long
return UTF8MaskInvalid | 3;
}
if ((*us == 0xef) && (us[1] == 0xbf) && (us[2] == 0xbf)) {
// U+FFFF non-character - 3 bytes long
return UTF8MaskInvalid | 3;
}
if ((*us == 0xef) && (us[1] == 0xb7) && (((us[2] & 0xf0) == 0x90) || ((us[2] & 0xf0) == 0xa0))) {
// U+FDD0 .. U+FDEF
return UTF8MaskInvalid | 3;
}
return 3;
} else {
return UTF8MaskInvalid | 1;
}
} else if (*us >= 0xc2) {
// 2 bytes
if (len < 2)
return UTF8MaskInvalid | 1;
if (UTF8IsTrailByte(us[1])) {
return 2;
} else {
return UTF8MaskInvalid | 1;
}
} else {
// 0xc0 .. 0xc1 is overlong encoding
// 0x80 .. 0xbf is trail byte
return UTF8MaskInvalid | 1;
}
}
