| /*===--- ConvertUTF.c - Universal Character Names conversions ---------------=== |
| * |
| * The LLVM Compiler Infrastructure |
| * |
| * This file is distributed under the University of Illinois Open Source |
| * License. See LICENSE.TXT for details. |
| * |
| *===------------------------------------------------------------------------=*/ |
| /* |
| * Copyright 2001-2004 Unicode, Inc. |
| * |
| * Disclaimer |
| * |
| * This source code is provided as is by Unicode, Inc. No claims are |
| * made as to fitness for any particular purpose. No warranties of any |
| * kind are expressed or implied. The recipient agrees to determine |
| * applicability of information provided. If this file has been |
| * purchased on magnetic or optical media from Unicode, Inc., the |
| * sole remedy for any claim will be exchange of defective media |
| * within 90 days of receipt. |
| * |
| * Limitations on Rights to Redistribute This Code |
| * |
| * Unicode, Inc. hereby grants the right to freely use the information |
| * supplied in this file in the creation of products supporting the |
| * Unicode Standard, and to make copies of this file in any form |
| * for internal or external distribution as long as this notice |
| * remains attached. |
| */ |
| |
| /* --------------------------------------------------------------------- |
| |
| Conversions between UTF32, UTF-16, and UTF-8. Source code file. |
| Author: Mark E. Davis, 1994. |
| Rev History: Rick McGowan, fixes & updates May 2001. |
| Sept 2001: fixed const & error conditions per |
| mods suggested by S. Parent & A. Lillich. |
| June 2002: Tim Dodd added detection and handling of incomplete |
| source sequences, enhanced error detection, added casts |
| to eliminate compiler warnings. |
| July 2003: slight mods to back out aggressive FFFE detection. |
| Jan 2004: updated switches in from-UTF8 conversions. |
| Oct 2004: updated to use UNI_MAX_LEGAL_UTF32 in UTF-32 conversions. |
| |
| See the header file "ConvertUTF.h" for complete documentation. |
| |
| ------------------------------------------------------------------------ */ |
| |
| |
| #include "llvm/Support/ConvertUTF.h" |
| #ifdef CVTUTF_DEBUG |
| #include <stdio.h> |
| #endif |
| |
| static const int halfShift = 10; /* used for shifting by 10 bits */ |
| |
| static const UTF32 halfBase = 0x0010000UL; |
| static const UTF32 halfMask = 0x3FFUL; |
| |
| #define UNI_SUR_HIGH_START (UTF32)0xD800 |
| #define UNI_SUR_HIGH_END (UTF32)0xDBFF |
| #define UNI_SUR_LOW_START (UTF32)0xDC00 |
| #define UNI_SUR_LOW_END (UTF32)0xDFFF |
| #define false 0 |
| #define true 1 |
| |
| /* --------------------------------------------------------------------- */ |
| |
| /* |
| * Index into the table below with the first byte of a UTF-8 sequence to |
| * get the number of trailing bytes that are supposed to follow it. |
| * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is |
| * left as-is for anyone who may want to do such conversion, which was |
| * allowed in earlier algorithms. |
| */ |
| static const char trailingBytesForUTF8[256] = { |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, |
| 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 |
| }; |
| |
| /* |
| * Magic values subtracted from a buffer value during UTF8 conversion. |
| * This table contains as many values as there might be trailing bytes |
| * in a UTF-8 sequence. |
| */ |
| static const UTF32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL, |
| 0x03C82080UL, 0xFA082080UL, 0x82082080UL }; |
| |
| /* |
| * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed |
| * into the first byte, depending on how many bytes follow. There are |
| * as many entries in this table as there are UTF-8 sequence types. |
| * (I.e., one byte sequence, two byte... etc.). Remember that sequencs |
| * for *legal* UTF-8 will be 4 or fewer bytes total. |
| */ |
| static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC }; |
| |
| /* --------------------------------------------------------------------- */ |
| |
| /* The interface converts a whole buffer to avoid function-call overhead. |
| * Constants have been gathered. Loops & conditionals have been removed as |
| * much as possible for efficiency, in favor of drop-through switches. |
| * (See "Note A" at the bottom of the file for equivalent code.) |
| * If your compiler supports it, the "isLegalUTF8" call can be turned |
| * into an inline function. |
| */ |
| |
| |
| /* --------------------------------------------------------------------- */ |
| |
| ConversionResult ConvertUTF32toUTF16 ( |
| const UTF32** sourceStart, const UTF32* sourceEnd, |
| UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) { |
| ConversionResult result = conversionOK; |
| const UTF32* source = *sourceStart; |
| UTF16* target = *targetStart; |
| while (source < sourceEnd) { |
| UTF32 ch; |
| if (target >= targetEnd) { |
| result = targetExhausted; break; |
| } |
| ch = *source++; |
| if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */ |
| /* UTF-16 surrogate values are illegal in UTF-32; 0xffff or 0xfffe are both reserved values */ |
| if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { |
| if (flags == strictConversion) { |
| --source; /* return to the illegal value itself */ |
| result = sourceIllegal; |
| break; |
| } else { |
| *target++ = UNI_REPLACEMENT_CHAR; |
| } |
| } else { |
| *target++ = (UTF16)ch; /* normal case */ |
| } |
| } else if (ch > UNI_MAX_LEGAL_UTF32) { |
| if (flags == strictConversion) { |
| result = sourceIllegal; |
| } else { |
| *target++ = UNI_REPLACEMENT_CHAR; |
| } |
| } else { |
| /* target is a character in range 0xFFFF - 0x10FFFF. */ |
| if (target + 1 >= targetEnd) { |
| --source; /* Back up source pointer! */ |
| result = targetExhausted; break; |
| } |
| ch -= halfBase; |
| *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START); |
| *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START); |
| } |
| } |
| *sourceStart = source; |
| *targetStart = target; |
| return result; |
| } |
| |
| /* --------------------------------------------------------------------- */ |
| |
| ConversionResult ConvertUTF16toUTF32 ( |
| const UTF16** sourceStart, const UTF16* sourceEnd, |
| UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) { |
| ConversionResult result = conversionOK; |
| const UTF16* source = *sourceStart; |
| UTF32* target = *targetStart; |
| UTF32 ch, ch2; |
| while (source < sourceEnd) { |
| const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */ |
| ch = *source++; |
| /* If we have a surrogate pair, convert to UTF32 first. */ |
| if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) { |
| /* If the 16 bits following the high surrogate are in the source buffer... */ |
| if (source < sourceEnd) { |
| ch2 = *source; |
| /* If it's a low surrogate, convert to UTF32. */ |
| if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) { |
| ch = ((ch - UNI_SUR_HIGH_START) << halfShift) |
| + (ch2 - UNI_SUR_LOW_START) + halfBase; |
| ++source; |
| } else if (flags == strictConversion) { /* it's an unpaired high surrogate */ |
| --source; /* return to the illegal value itself */ |
| result = sourceIllegal; |
| break; |
| } |
| } else { /* We don't have the 16 bits following the high surrogate. */ |
| --source; /* return to the high surrogate */ |
| result = sourceExhausted; |
| break; |
| } |
| } else if (flags == strictConversion) { |
| /* UTF-16 surrogate values are illegal in UTF-32 */ |
| if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) { |
| --source; /* return to the illegal value itself */ |
| result = sourceIllegal; |
| break; |
| } |
| } |
| if (target >= targetEnd) { |
| source = oldSource; /* Back up source pointer! */ |
| result = targetExhausted; break; |
| } |
| *target++ = ch; |
| } |
| *sourceStart = source; |
| *targetStart = target; |
| #ifdef CVTUTF_DEBUG |
| if (result == sourceIllegal) { |
| fprintf(stderr, "ConvertUTF16toUTF32 illegal seq 0x%04x,%04x\n", ch, ch2); |
| fflush(stderr); |
| } |
| #endif |
| return result; |
| } |
| ConversionResult ConvertUTF16toUTF8 ( |
| const UTF16** sourceStart, const UTF16* sourceEnd, |
| UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) { |
| ConversionResult result = conversionOK; |
| const UTF16* source = *sourceStart; |
| UTF8* target = *targetStart; |
| while (source < sourceEnd) { |
| UTF32 ch; |
| unsigned short bytesToWrite = 0; |
| const UTF32 byteMask = 0xBF; |
| const UTF32 byteMark = 0x80; |
| const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */ |
| ch = *source++; |
| /* If we have a surrogate pair, convert to UTF32 first. */ |
| if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) { |
| /* If the 16 bits following the high surrogate are in the source buffer... */ |
| if (source < sourceEnd) { |
| UTF32 ch2 = *source; |
| /* If it's a low surrogate, convert to UTF32. */ |
| if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) { |
| ch = ((ch - UNI_SUR_HIGH_START) << halfShift) |
| + (ch2 - UNI_SUR_LOW_START) + halfBase; |
| ++source; |
| } else if (flags == strictConversion) { /* it's an unpaired high surrogate */ |
| --source; /* return to the illegal value itself */ |
| result = sourceIllegal; |
| break; |
| } |
| } else { /* We don't have the 16 bits following the high surrogate. */ |
| --source; /* return to the high surrogate */ |
| result = sourceExhausted; |
| break; |
| } |
| } else if (flags == strictConversion) { |
| /* UTF-16 surrogate values are illegal in UTF-32 */ |
| if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) { |
| --source; /* return to the illegal value itself */ |
| result = sourceIllegal; |
| break; |
| } |
| } |
| /* Figure out how many bytes the result will require */ |
| if (ch < (UTF32)0x80) { bytesToWrite = 1; |
| } else if (ch < (UTF32)0x800) { bytesToWrite = 2; |
| } else if (ch < (UTF32)0x10000) { bytesToWrite = 3; |
| } else if (ch < (UTF32)0x110000) { bytesToWrite = 4; |
| } else { bytesToWrite = 3; |
| ch = UNI_REPLACEMENT_CHAR; |
| } |
| |
| target += bytesToWrite; |
| if (target > targetEnd) { |
| source = oldSource; /* Back up source pointer! */ |
| target -= bytesToWrite; result = targetExhausted; break; |
| } |
| switch (bytesToWrite) { /* note: everything falls through. */ |
| case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| case 1: *--target = (UTF8)(ch | firstByteMark[bytesToWrite]); |
| } |
| target += bytesToWrite; |
| } |
| *sourceStart = source; |
| *targetStart = target; |
| return result; |
| } |
| |
| /* --------------------------------------------------------------------- */ |
| |
| ConversionResult ConvertUTF32toUTF8 ( |
| const UTF32** sourceStart, const UTF32* sourceEnd, |
| UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) { |
| ConversionResult result = conversionOK; |
| const UTF32* source = *sourceStart; |
| UTF8* target = *targetStart; |
| while (source < sourceEnd) { |
| UTF32 ch; |
| unsigned short bytesToWrite = 0; |
| const UTF32 byteMask = 0xBF; |
| const UTF32 byteMark = 0x80; |
| ch = *source++; |
| if (flags == strictConversion ) { |
| /* UTF-16 surrogate values are illegal in UTF-32 */ |
| if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { |
| --source; /* return to the illegal value itself */ |
| result = sourceIllegal; |
| break; |
| } |
| } |
| /* |
| * Figure out how many bytes the result will require. Turn any |
| * illegally large UTF32 things (> Plane 17) into replacement chars. |
| */ |
| if (ch < (UTF32)0x80) { bytesToWrite = 1; |
| } else if (ch < (UTF32)0x800) { bytesToWrite = 2; |
| } else if (ch < (UTF32)0x10000) { bytesToWrite = 3; |
| } else if (ch <= UNI_MAX_LEGAL_UTF32) { bytesToWrite = 4; |
| } else { bytesToWrite = 3; |
| ch = UNI_REPLACEMENT_CHAR; |
| result = sourceIllegal; |
| } |
| |
| target += bytesToWrite; |
| if (target > targetEnd) { |
| --source; /* Back up source pointer! */ |
| target -= bytesToWrite; result = targetExhausted; break; |
| } |
| switch (bytesToWrite) { /* note: everything falls through. */ |
| case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| case 1: *--target = (UTF8) (ch | firstByteMark[bytesToWrite]); |
| } |
| target += bytesToWrite; |
| } |
| *sourceStart = source; |
| *targetStart = target; |
| return result; |
| } |
| |
| /* --------------------------------------------------------------------- */ |
| |
| /* |
| * Utility routine to tell whether a sequence of bytes is legal UTF-8. |
| * This must be called with the length pre-determined by the first byte. |
| * If not calling this from ConvertUTF8to*, then the length can be set by: |
| * length = trailingBytesForUTF8[*source]+1; |
| * and the sequence is illegal right away if there aren't that many bytes |
| * available. |
| * If presented with a length > 4, this returns false. The Unicode |
| * definition of UTF-8 goes up to 4-byte sequences. |
| */ |
| |
| static Boolean isLegalUTF8(const UTF8 *source, int length) { |
| UTF8 a; |
| const UTF8 *srcptr = source+length; |
| switch (length) { |
| default: return false; |
| /* Everything else falls through when "true"... */ |
| case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; |
| case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; |
| case 2: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; |
| |
| switch (*source) { |
| /* no fall-through in this inner switch */ |
| case 0xE0: if (a < 0xA0) return false; break; |
| case 0xED: if (a > 0x9F) return false; break; |
| case 0xF0: if (a < 0x90) return false; break; |
| case 0xF4: if (a > 0x8F) return false; break; |
| default: if (a < 0x80) return false; |
| } |
| |
| case 1: if (*source >= 0x80 && *source < 0xC2) return false; |
| } |
| if (*source > 0xF4) return false; |
| return true; |
| } |
| |
| /* --------------------------------------------------------------------- */ |
| |
| /* |
| * Exported function to return whether a UTF-8 sequence is legal or not. |
| * This is not used here; it's just exported. |
| */ |
| Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd) { |
| int length = trailingBytesForUTF8[*source]+1; |
| if (length > sourceEnd - source) { |
| return false; |
| } |
| return isLegalUTF8(source, length); |
| } |
| |
| /* --------------------------------------------------------------------- */ |
| |
| /* |
| * Exported function to return the total number of bytes in a codepoint |
| * represented in UTF-8, given the value of the first byte. |
| */ |
| unsigned getNumBytesForUTF8(UTF8 first) { |
| return trailingBytesForUTF8[first] + 1; |
| } |
| |
| /* --------------------------------------------------------------------- */ |
| |
| /* |
| * Exported function to return whether a UTF-8 string is legal or not. |
| * This is not used here; it's just exported. |
| */ |
| Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd) { |
| while (*source != sourceEnd) { |
| int length = trailingBytesForUTF8[**source] + 1; |
| if (length > sourceEnd - *source || !isLegalUTF8(*source, length)) |
| return false; |
| *source += length; |
| } |
| return true; |
| } |
| |
| /* --------------------------------------------------------------------- */ |
| |
| ConversionResult ConvertUTF8toUTF16 ( |
| const UTF8** sourceStart, const UTF8* sourceEnd, |
| UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) { |
| ConversionResult result = conversionOK; |
| const UTF8* source = *sourceStart; |
| UTF16* target = *targetStart; |
| while (source < sourceEnd) { |
| UTF32 ch = 0; |
| unsigned short extraBytesToRead = trailingBytesForUTF8[*source]; |
| if (extraBytesToRead >= sourceEnd - source) { |
| result = sourceExhausted; break; |
| } |
| /* Do this check whether lenient or strict */ |
| if (!isLegalUTF8(source, extraBytesToRead+1)) { |
| result = sourceIllegal; |
| break; |
| } |
| /* |
| * The cases all fall through. See "Note A" below. |
| */ |
| switch (extraBytesToRead) { |
| case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ |
| case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ |
| case 3: ch += *source++; ch <<= 6; |
| case 2: ch += *source++; ch <<= 6; |
| case 1: ch += *source++; ch <<= 6; |
| case 0: ch += *source++; |
| } |
| ch -= offsetsFromUTF8[extraBytesToRead]; |
| |
| if (target >= targetEnd) { |
| source -= (extraBytesToRead+1); /* Back up source pointer! */ |
| result = targetExhausted; break; |
| } |
| if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */ |
| /* UTF-16 surrogate values are illegal in UTF-32 */ |
| if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { |
| if (flags == strictConversion) { |
| source -= (extraBytesToRead+1); /* return to the illegal value itself */ |
| result = sourceIllegal; |
| break; |
| } else { |
| *target++ = UNI_REPLACEMENT_CHAR; |
| } |
| } else { |
| *target++ = (UTF16)ch; /* normal case */ |
| } |
| } else if (ch > UNI_MAX_UTF16) { |
| if (flags == strictConversion) { |
| result = sourceIllegal; |
| source -= (extraBytesToRead+1); /* return to the start */ |
| break; /* Bail out; shouldn't continue */ |
| } else { |
| *target++ = UNI_REPLACEMENT_CHAR; |
| } |
| } else { |
| /* target is a character in range 0xFFFF - 0x10FFFF. */ |
| if (target + 1 >= targetEnd) { |
| source -= (extraBytesToRead+1); /* Back up source pointer! */ |
| result = targetExhausted; break; |
| } |
| ch -= halfBase; |
| *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START); |
| *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START); |
| } |
| } |
| *sourceStart = source; |
| *targetStart = target; |
| return result; |
| } |
| |
| /* --------------------------------------------------------------------- */ |
| |
| ConversionResult ConvertUTF8toUTF32 ( |
| const UTF8** sourceStart, const UTF8* sourceEnd, |
| UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) { |
| ConversionResult result = conversionOK; |
| const UTF8* source = *sourceStart; |
| UTF32* target = *targetStart; |
| while (source < sourceEnd) { |
| UTF32 ch = 0; |
| unsigned short extraBytesToRead = trailingBytesForUTF8[*source]; |
| if (extraBytesToRead >= sourceEnd - source) { |
| result = sourceExhausted; break; |
| } |
| /* Do this check whether lenient or strict */ |
| if (!isLegalUTF8(source, extraBytesToRead+1)) { |
| result = sourceIllegal; |
| break; |
| } |
| /* |
| * The cases all fall through. See "Note A" below. |
| */ |
| switch (extraBytesToRead) { |
| case 5: ch += *source++; ch <<= 6; |
| case 4: ch += *source++; ch <<= 6; |
| case 3: ch += *source++; ch <<= 6; |
| case 2: ch += *source++; ch <<= 6; |
| case 1: ch += *source++; ch <<= 6; |
| case 0: ch += *source++; |
| } |
| ch -= offsetsFromUTF8[extraBytesToRead]; |
| |
| if (target >= targetEnd) { |
| source -= (extraBytesToRead+1); /* Back up the source pointer! */ |
| result = targetExhausted; break; |
| } |
| if (ch <= UNI_MAX_LEGAL_UTF32) { |
| /* |
| * UTF-16 surrogate values are illegal in UTF-32, and anything |
| * over Plane 17 (> 0x10FFFF) is illegal. |
| */ |
| if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { |
| if (flags == strictConversion) { |
| source -= (extraBytesToRead+1); /* return to the illegal value itself */ |
| result = sourceIllegal; |
| break; |
| } else { |
| *target++ = UNI_REPLACEMENT_CHAR; |
| } |
| } else { |
| *target++ = ch; |
| } |
| } else { /* i.e., ch > UNI_MAX_LEGAL_UTF32 */ |
| result = sourceIllegal; |
| *target++ = UNI_REPLACEMENT_CHAR; |
| } |
| } |
| *sourceStart = source; |
| *targetStart = target; |
| return result; |
| } |
| |
| /* --------------------------------------------------------------------- |
| |
| Note A. |
| The fall-through switches in UTF-8 reading code save a |
| temp variable, some decrements & conditionals. The switches |
| are equivalent to the following loop: |
| { |
| int tmpBytesToRead = extraBytesToRead+1; |
| do { |
| ch += *source++; |
| --tmpBytesToRead; |
| if (tmpBytesToRead) ch <<= 6; |
| } while (tmpBytesToRead > 0); |
| } |
| In UTF-8 writing code, the switches on "bytesToWrite" are |
| similarly unrolled loops. |
| |
| --------------------------------------------------------------------- */ |
