Use the ConvertUTF.cpp from breakpad which is under a compatible license And reintegrate our custom changes

[sylvestre.ledru]

Summary

It breaks the following tests

LLVM-Unit :: Support/./SupportTests/ConvertUTFTest.ConvertUTF8toWide
LLVM-Unit :: Support/./SupportTests/ConvertUTFTest.UTF8ToUTF32Lenient
LLVM-Unit :: Support/./SupportTests/ConvertUTFTest.UTF8ToUTF32PartialLenient
LLVM-Unit :: Support/./SupportTests/ConvertUTFTest.convertWideToUTF8
LLVM-Unit :: Support/./SupportTests/JSONTest.UTF8

but only these (making me wonder if these tests are interesting or not)

[mgorny]

Any chance to move this forward? I've just noticed we're missing this one license, and fixing it would render LLVM non-free in Gentoo (read: cause a massive shitstorm for some of our users). I just wanted to do a similar port and found this while looking for earlier work.

unittests/Support/ConvertUTFTest.cpp

166

Why is this commented out? It looks at least weird, with no comment to explain it.

[mgorny]

Actually, I think the license change can be submitted separately, so I'll do just that.

[sylvestre.ledru]

unittests/Support/ConvertUTFTest.cpp

166

I think i removed it to build.
It should indeed be fixed or commented

[mgorny]

Do you want me to try to take a look at the problems?

[sylvestre.ledru]

With pleasure :)

[mgorny]

@sylvestre.ledru, I just went through breakpad code, comparing it with the initial code imported to clang. After reordering and aligning whitespace, the code is identical. This means that 1) the tests are failing because of regressions reintroduced by porting breakpad code, and 2) we can just change the license header because all differences in code are of our own making. Therefore, I propose that we go forward with D66390 instead of putting more time into regressing code just to fix it again.

include/llvm/Support/ConvertUTF.h

-/*===--- ConvertUTF.h - Universal Character Names conversions ---------------===
- *
- * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
- * See https://llvm.org/LICENSE.txt for license information.
- * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
- *
- *==------------------------------------------------------------------------==*/
 /*
- * 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.
+ * Copyright © 1991-2015 Unicode, Inc. All rights reserved.
+ * Distributed under the Terms of Use in 
+ * http://www.unicode.org/copyright.html.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of the Unicode data files and any associated documentation
+ * (the "Data Files") or Unicode software and any associated documentation
+ * (the "Software") to deal in the Data Files or Software
+ * without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, and/or sell copies of
+ * the Data Files or Software, and to permit persons to whom the Data Files
+ * or Software are furnished to do so, provided that
+ * (a) this copyright and permission notice appear with all copies 
+ * of the Data Files or Software,
+ * (b) this copyright and permission notice appear in associated 
+ * documentation, and
+ * (c) there is clear notice in each modified Data File or in the Software
+ * as well as in the documentation associated with the Data File(s) or
+ * Software that the data or software has been modified.
+ *
+ * THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF
+ * ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+ * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS
+ * NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL
+ * DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THE DATA FILES OR SOFTWARE.
+ *
+ * Except as contained in this notice, the name of a copyright holder
+ * shall not be used in advertising or otherwise to promote the sale,
+ * use or other dealings in these Data Files or Software without prior
+ * written authorization of the copyright holder.
  */
 
+#ifndef COMMON_CONVERT_UTF_H_
+#define COMMON_CONVERT_UTF_H_
+
 /* ---------------------------------------------------------------------
 
-    Conversions between UTF32, UTF-16, and UTF-8.  Header file.
 
-    Several funtions are included here, forming a complete set of
-    conversions between the three formats.  UTF-7 is not included
-    here, but is handled in a separate source file.
 
-    Each of these routines takes pointers to input buffers and output
-    buffers.  The input buffers are const.
 
-    Each routine converts the text between *sourceStart and sourceEnd,
-    putting the result into the buffer between *targetStart and
-    targetEnd. Note: the end pointers are *after* the last item: e.g.
-    *(sourceEnd - 1) is the last item.
 
-    The return result indicates whether the conversion was successful,
-    and if not, whether the problem was in the source or target buffers.
-    (Only the first encountered problem is indicated.)
 
-    After the conversion, *sourceStart and *targetStart are both
-    updated to point to the end of last text successfully converted in
-    the respective buffers.
 
-    Input parameters:
-        sourceStart - pointer to a pointer to the source buffer.
-                The contents of this are modified on return so that
-                it points at the next thing to be converted.
-        targetStart - similarly, pointer to pointer to the target buffer.
-        sourceEnd, targetEnd - respectively pointers to the ends of the
-                two buffers, for overflow checking only.
 
-    These conversion functions take a ConversionFlags argument. When this
-    flag is set to strict, both irregular sequences and isolated surrogates
-    will cause an error.  When the flag is set to lenient, both irregular
-    sequences and isolated surrogates are converted.
 
-    Whether the flag is strict or lenient, all illegal sequences will cause
-    an error return. This includes sequences such as: <F4 90 80 80>, <C0 80>,
-    or <A0> in UTF-8, and values above 0x10FFFF in UTF-32. Conformant code
-    must check for illegal sequences.
 
-    When the flag is set to lenient, characters over 0x10FFFF are converted
-    to the replacement character; otherwise (when the flag is set to strict)
-    they constitute an error.
 
-    Output parameters:
-        The value "sourceIllegal" is returned from some routines if the input
-        sequence is malformed.  When "sourceIllegal" is returned, the source
-        value will point to the illegal value that caused the problem. E.g.,
-        in UTF-8 when a sequence is malformed, it points to the start of the
-        malformed sequence.
 
-    Author: Mark E. Davis, 1994.
-    Rev History: Rick McGowan, fixes & updates May 2001.
-         Fixes & updates, Sept 2001.
 
 ------------------------------------------------------------------------ */
 
 #ifndef LLVM_SUPPORT_CONVERTUTF_H
 #define LLVM_SUPPORT_CONVERTUTF_H
 
 #include <cstddef>
 #include <string>
 #include <system_error>
 
 // Wrap everything in namespace llvm so that programs can link with llvm and
 // their own version of the unicode libraries.
 
 namespace llvm {
 
 /* ---------------------------------------------------------------------
-    The following 4 definitions are compiler-specific.
-    The C standard does not guarantee that wchar_t has at least
-    16 bits, so wchar_t is no less portable than unsigned short!
-    All should be unsigned values to avoid sign extension during
-    bit mask & shift operations.
 ------------------------------------------------------------------------ */
 
-typedef unsigned int    UTF32;  /* at least 32 bits */
-typedef unsigned short  UTF16;  /* at least 16 bits */
-typedef unsigned char   UTF8;   /* typically 8 bits */
-typedef unsigned char   Boolean; /* 0 or 1 */
+typedef unsigned long  UTF32;  /* at least 32 bits */
+typedef unsigned short  UTF16;  /* at least 16 bits */
+typedef unsigned char  UTF8;  /* typically 8 bits */
+typedef unsigned char Boolean; /* 0 or 1 */
 
 /* Some fundamental constants */
 #define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD
 #define UNI_MAX_BMP (UTF32)0x0000FFFF
 #define UNI_MAX_UTF16 (UTF32)0x0010FFFF
 #define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF
 #define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF
 
 #define UNI_MAX_UTF8_BYTES_PER_CODE_POINT 4
 
 #define UNI_UTF16_BYTE_ORDER_MARK_NATIVE  0xFEFF
 #define UNI_UTF16_BYTE_ORDER_MARK_SWAPPED 0xFFFE
 
 typedef enum {
-  conversionOK,           /* conversion successful */
-  sourceExhausted,        /* partial character in source, but hit end */
-  targetExhausted,        /* insuff. room in target for conversion */
-  sourceIllegal           /* source sequence is illegal/malformed */
+  conversionOK,     /* conversion successful */
+  sourceExhausted,  /* partial character in source, but hit end */
+  targetExhausted,  /* insuff. room in target for conversion */
+  sourceIllegal   /* source sequence is illegal/malformed */
 } ConversionResult;
 
 typedef enum {
-  strictConversion = 0,
-  lenientConversion
+  strictConversion = 0,
+  lenientConversion
 } ConversionFlags;
 
-ConversionResult ConvertUTF8toUTF16 (
-  const UTF8** sourceStart, const UTF8* sourceEnd,
-  UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
+/* This is for C++ and does no harm in C */
+#ifdef __cplusplus
+extern "C" {
+#endif
 
-/**
- * Convert a partial UTF8 sequence to UTF32.  If the sequence ends in an
- * incomplete code unit sequence, returns \c sourceExhausted.
- */
-ConversionResult ConvertUTF8toUTF32Partial(
-  const UTF8** sourceStart, const UTF8* sourceEnd,
-  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
 
-/**
- * Convert a partial UTF8 sequence to UTF32.  If the sequence ends in an
- * incomplete code unit sequence, returns \c sourceIllegal.
- */
-ConversionResult ConvertUTF8toUTF32(
-  const UTF8** sourceStart, const UTF8* sourceEnd,
-  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
+ConversionResult ConvertUTF8toUTF16 (const UTF8** sourceStart, const UTF8* sourceEnd,
+                                     UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
 
-ConversionResult ConvertUTF16toUTF8 (
-  const UTF16** sourceStart, const UTF16* sourceEnd,
+ConversionResult ConvertUTF16toUTF8 (const UTF16** sourceStart, const UTF16* sourceEnd,
                                      UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
 
-ConversionResult ConvertUTF32toUTF8 (
-  const UTF32** sourceStart, const UTF32* sourceEnd,
+ConversionResult ConvertUTF8toUTF32 (const UTF8** sourceStart, const UTF8* sourceEnd,
+                                     UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
+
+ConversionResult ConvertUTF32toUTF8 (const UTF32** sourceStart, const UTF32* sourceEnd,
                                      UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
 
-ConversionResult ConvertUTF16toUTF32 (
-  const UTF16** sourceStart, const UTF16* sourceEnd,
+ConversionResult ConvertUTF16toUTF32 (const UTF16** sourceStart, const UTF16* sourceEnd,
                                       UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
 
-ConversionResult ConvertUTF32toUTF16 (
-  const UTF32** sourceStart, const UTF32* sourceEnd,
+ConversionResult ConvertUTF32toUTF16 (const UTF32** sourceStart, const UTF32* sourceEnd,
                                       UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
 
 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd);
 
 Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd);
 
 unsigned getNumBytesForUTF8(UTF8 firstByte);
 
+#ifdef __cplusplus
+}
+#endif
+
+/* --------------------------------------------------------------------- */
+
 /*************************************************************************/
 /* Below are LLVM-specific wrappers of the functions above. */
 
 template <typename T> class ArrayRef;
 template <typename T> class SmallVectorImpl;
 class StringRef;
 
 /**
std::error_code UTF16ToCurCP(const wchar_t *utf16, size_t utf16_len,
                              SmallVectorImpl<char> &utf8);
 } // namespace windows
 } // namespace sys
 #endif
 
 } /* end namespace llvm */
 
 #endif
+
+#endif  // COMMON_CONVERT_UTF_H_

lib/Support/ConvertUTF.cpp

-/*===--- ConvertUTF.c - Universal Character Names conversions ---------------===
- *
- * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
- * See https://llvm.org/LICENSE.txt for license information.
- * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
- *
- *===------------------------------------------------------------------------=*/
 /*
- * Copyright 2001-2004 Unicode, Inc.
- *
- * Disclaimer
+ * Copyright © 1991-2015 Unicode, Inc. All rights reserved.
+ * Distributed under the Terms of Use in 
+ * http://www.unicode.org/copyright.html.
  *
- * 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.
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of the Unicode data files and any associated documentation
+ * (the "Data Files") or Unicode software and any associated documentation
+ * (the "Software") to deal in the Data Files or Software
+ * without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, and/or sell copies of
+ * the Data Files or Software, and to permit persons to whom the Data Files
+ * or Software are furnished to do so, provided that
+ * (a) this copyright and permission notice appear with all copies 
+ * of the Data Files or Software,
+ * (b) this copyright and permission notice appear in associated 
+ * documentation, and
+ * (c) there is clear notice in each modified Data File or in the Software
+ * as well as in the documentation associated with the Data File(s) or
+ * Software that the data or software has been modified.
  *
- * Limitations on Rights to Redistribute This Code
+ * THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF
+ * ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+ * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS
+ * NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL
+ * DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THE DATA FILES OR SOFTWARE.
  *
- * 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.
+ * Except as contained in this notice, the name of a copyright holder
+ * shall not be used in advertising or otherwise to promote the sale,
+ * use or other dealings in these Data Files or Software without prior
+ * written authorization of the copyright holder.
  */
 
 /* ---------------------------------------------------------------------
 
-    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
-#include <assert.h>
+
 
 /*
  * This code extensively uses fall-through switches.
  * Keep the compiler from warning about that.
  */
 #if defined(__clang__) && defined(__has_warning)
 # if __has_warning("-Wimplicit-fallthrough")
 #  define ConvertUTF_DISABLE_WARNINGS \

 #ifndef ConvertUTF_RESTORE_WARNINGS
 # define ConvertUTF_RESTORE_WARNINGS
 #endif
 
 ConvertUTF_DISABLE_WARNINGS
 
 namespace llvm {
 
+
 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
 
-/* --------------------------------------------------------------------- */
-
-/*
- * 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.
- */
-
+#ifndef false
+#define false    0
+#endif
+#ifndef true
+#define true      1
+#endif
 
 /* --------------------------------------------------------------------- */
 
-ConversionResult ConvertUTF32toUTF16 (
-        const UTF32** sourceStart, const UTF32* sourceEnd,
+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;
+      result = targetExhausted; break;
+      /* 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) {
+      } else {
+      }
+      if (flags == strictConversion) {
+      } else {
+      }
+      /* target is a character in range 0xFFFF - 0x10FFFF. */
+      if (target + 1 >= targetEnd) {
+      }
+      ch -= halfBase;
+      *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
+      *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
 }
 
 /* --------------------------------------------------------------------- */
 
-ConversionResult ConvertUTF16toUTF32 (
-        const UTF16** sourceStart, const UTF16* sourceEnd,
+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;
+      /* If the 16 bits following the high surrogate are in the source buffer... */
+      if (source < sourceEnd) {
+      } else { /* We don't have the 16 bits following the high surrogate. */
+      }
+      /* UTF-16 surrogate values are illegal in UTF-32 */
+      if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
+      }
+      source = oldSource; /* Back up source pointer! */
+      result = targetExhausted; break;
 #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,
+
+/* --------------------------------------------------------------------- */
+
+/*
+ * 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 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;
-        }
+      /* If the 16 bits following the high surrogate are in the source buffer... */
+      if (source < sourceEnd) {
+      } else { /* We don't have the 16 bits following the high surrogate. */
+      }
+      /* UTF-16 surrogate values are illegal in UTF-32 */
+      if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
+      }
+    if (ch < (UTF32)0x80) {       bytesToWrite = 1;
+    } else {          bytesToWrite = 3;
 
-        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;
+      source = oldSource; /* Back up source pointer! */
+      target -= bytesToWrite; result = targetExhausted; break;
+      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]);
 }
 
 /* --------------------------------------------------------------------- */
 
-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;
+    case 2: if ((a = (*--srcptr)) > 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);
-}
-
-/* --------------------------------------------------------------------- */
-
-static unsigned
-findMaximalSubpartOfIllFormedUTF8Sequence(const UTF8 *source,
-                                          const UTF8 *sourceEnd) {
-  UTF8 b1, b2, b3;
-
-  assert(!isLegalUTF8Sequence(source, sourceEnd));
-
-  /*
-   * Unicode 6.3.0, D93b:
-   *
-   *   Maximal subpart of an ill-formed subsequence: The longest code unit
-   *   subsequence starting at an unconvertible offset that is either:
-   *   a. the initial subsequence of a well-formed code unit sequence, or
-   *   b. a subsequence of length one.
-   */
-
-  if (source == sourceEnd)
-    return 0;
-
-  /*
-   * Perform case analysis.  See Unicode 6.3.0, Table 3-7. Well-Formed UTF-8
-   * Byte Sequences.
-   */
-
-  b1 = *source;
-  ++source;
-  if (b1 >= 0xC2 && b1 <= 0xDF) {
-    /*
-     * First byte is valid, but we know that this code unit sequence is
-     * invalid, so the maximal subpart has to end after the first byte.
-     */
-    return 1;
-  }
-
-  if (source == sourceEnd)
-    return 1;
-
-  b2 = *source;
-  ++source;
-
-  if (b1 == 0xE0) {
-    return (b2 >= 0xA0 && b2 <= 0xBF) ? 2 : 1;
-  }
-  if (b1 >= 0xE1 && b1 <= 0xEC) {
-    return (b2 >= 0x80 && b2 <= 0xBF) ? 2 : 1;
-  }
-  if (b1 == 0xED) {
-    return (b2 >= 0x80 && b2 <= 0x9F) ? 2 : 1;
-  }
-  if (b1 >= 0xEE && b1 <= 0xEF) {
-    return (b2 >= 0x80 && b2 <= 0xBF) ? 2 : 1;
-  }
-  if (b1 == 0xF0) {
-    if (b2 >= 0x90 && b2 <= 0xBF) {
-      if (source == sourceEnd)
-        return 2;
-
-      b3 = *source;
-      return (b3 >= 0x80 && b3 <= 0xBF) ? 3 : 2;
-    }
-    return 1;
-  }
-  if (b1 >= 0xF1 && b1 <= 0xF3) {
-    if (b2 >= 0x80 && b2 <= 0xBF) {
-      if (source == sourceEnd)
-        return 2;
-
-      b3 = *source;
-      return (b3 >= 0x80 && b3 <= 0xBF) ? 3 : 2;
-    }
-    return 1;
-  }
-  if (b1 == 0xF4) {
-    if (b2 >= 0x80 && b2 <= 0x8F) {
-      if (source == sourceEnd)
-        return 2;
-
-      b3 = *source;
-      return (b3 >= 0x80 && b3 <= 0xBF) ? 3 : 2;
-    }
-    return 1;
-  }
-
-  assert((b1 >= 0x80 && b1 <= 0xC1) || b1 >= 0xF5);
-  /*
-   * There are no valid sequences that start with these bytes.  Maximal subpart
-   * is defined to have length 1 in these cases.
-   */
-  return 1;
-}
-
-/* --------------------------------------------------------------------- */
-
-/*
  * 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;
 }
 
+/*
+ * 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 (source+length > sourceEnd) {
+    return false;
+  }
+  return isLegalUTF8(source, length);
+}
+
 /* --------------------------------------------------------------------- */
 
-ConversionResult ConvertUTF8toUTF16 (
-        const UTF8** sourceStart, const UTF8* sourceEnd,
+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 (source + extraBytesToRead >= sourceEnd) {
+      result = sourceExhausted; break;
+    if (! isLegalUTF8(source, extraBytesToRead+1)) {
+      result = sourceIllegal;
+      break;
+      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++;
 
-        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;
+      source -= (extraBytesToRead+1); /* Back up source pointer! */
+      result = targetExhausted; break;
+      /* UTF-16 surrogate values are illegal in UTF-32 */
+      if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
+      } else {
+      }
+      if (flags == strictConversion) {
+      } else {
+      }
+      /* target is a character in range 0xFFFF - 0x10FFFF. */
+      if (target + 1 >= targetEnd) {
+      }
+      ch -= halfBase;
+      *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
+      *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
 }
 
 /* --------------------------------------------------------------------- */
 
-static ConversionResult ConvertUTF8toUTF32Impl(
-        const UTF8** sourceStart, const UTF8* sourceEnd,
-        UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags,
-        Boolean InputIsPartial) {
-    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) {
-            if (flags == strictConversion || InputIsPartial) {
-                result = sourceExhausted;
-                break;
-            } else {
-                result = sourceIllegal;
-
-                /*
-                 * Replace the maximal subpart of ill-formed sequence with
-                 * replacement character.
-                 */
-                source += findMaximalSubpartOfIllFormedUTF8Sequence(source,
-                                                                    sourceEnd);
-                *target++ = UNI_REPLACEMENT_CHAR;
-                continue;
-            }
-        }
-        if (target >= targetEnd) {
-            result = targetExhausted; break;
-        }
+ConversionResult ConvertUTF32toUTF8 (const UTF32** sourceStart, const UTF32* sourceEnd,
+                                     UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) {
+  const UTF32* source = *sourceStart;
+  UTF8* target = *targetStart;
+    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 */
+        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;
 
-        /* Do this check whether lenient or strict */
-        if (!isLegalUTF8(source, extraBytesToRead+1)) {
-            result = sourceIllegal;
-            if (flags == strictConversion) {
-                /* Abort conversion. */
-                break;
-            } else {
-                /*
-                 * Replace the maximal subpart of ill-formed sequence with
-                 * replacement character.
-                 */
-                source += findMaximalSubpartOfIllFormedUTF8Sequence(source,
-                                                                    sourceEnd);
-                *target++ = UNI_REPLACEMENT_CHAR;
-                continue;
-            }
-        }
-        /*
-         * 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];
+/* --------------------------------------------------------------------- */
+
+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 (source + extraBytesToRead >= sourceEnd) {
+      result = sourceExhausted; break;
+    }
+    if (! isLegalUTF8(source, extraBytesToRead+1)) {
+      result = sourceIllegal;
+      break;
+      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++;
 
-        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;
+    if (target >= targetEnd) {
+      source -= (extraBytesToRead+1); /* Back up the source pointer! */
+      result = targetExhausted; break;
+    }
+      /*
+       * 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) {
+      } else {
+      }
+      result = sourceIllegal;
+      *target++ = UNI_REPLACEMENT_CHAR;
 }
 
-ConversionResult ConvertUTF8toUTF32Partial(const UTF8 **sourceStart,
-                                           const UTF8 *sourceEnd,
-                                           UTF32 **targetStart,
-                                           UTF32 *targetEnd,
-                                           ConversionFlags flags) {
-  return ConvertUTF8toUTF32Impl(sourceStart, sourceEnd, targetStart, targetEnd,
-                                flags, /*InputIsPartial=*/true);
-}
-
-ConversionResult ConvertUTF8toUTF32(const UTF8 **sourceStart,
-                                    const UTF8 *sourceEnd, UTF32 **targetStart,
-                                    UTF32 *targetEnd, ConversionFlags flags) {
-  return ConvertUTF8toUTF32Impl(sourceStart, sourceEnd, targetStart, targetEnd,
-                                flags, /*InputIsPartial=*/false);
-}
-
 /* ---------------------------------------------------------------------
 
-    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.
+    ch += *source++;
+    --tmpBytesToRead;
+    if (tmpBytesToRead) ch <<= 6;
 
-   --------------------------------------------------------------------- */
 
 } // namespace llvm
 
 ConvertUTF_RESTORE_WARNINGS

lib/Support/ConvertUTFWrapper.cpp

if (WideCharWidth == 1) {
     else
       ErrorPtr = sourceStart;
   }
   assert((result != targetExhausted)
          && "ConvertUTF8toUTFXX exhausted target buffer");
   return result == conversionOK;
 }
 
-bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr) {
+bool ConvertCodePointToUTF8(unsigned long Source, char *&ResultPtr) {
   const UTF32 *SourceStart = &Source;
   const UTF32 *SourceEnd = SourceStart + 1;
   UTF8 *TargetStart = reinterpret_cast<UTF8 *>(ResultPtr);
   UTF8 *TargetEnd = TargetStart + 4;
   ConversionResult CR = ConvertUTF32toUTF8(&SourceStart, SourceEnd,
                                            &TargetStart, TargetEnd,
                                            strictConversion);
   if (CR != conversionOK)

unittests/Support/ConvertUTFTest.cpp

TEST(ConvertUTFTest, convertWideToUTF8) {
   bool Success = convertWideToUTF8(Src, Result);
   EXPECT_TRUE(Success);
   std::string Expected("\xe0\xb2\xa0_\xe0\xb2\xa0");
   EXPECT_EQ(Expected, Result);
 }
 
 struct ConvertUTFResultContainer {
   ConversionResult ErrorCode;
-  std::vector<unsigned> UnicodeScalars;
+  std::vector<unsigned long> UnicodeScalars;
 
   ConvertUTFResultContainer(ConversionResult ErrorCode)
       : ErrorCode(ErrorCode) {}
 
   ConvertUTFResultContainer
   withScalars(unsigned US0 = 0x110000, unsigned US1 = 0x110000,
               unsigned US2 = 0x110000, unsigned US3 = 0x110000,
               unsigned US4 = 0x110000, unsigned US5 = 0x110000,
withScalars(unsigned US0 = 0x110000, unsigned US1 = 0x110000,
     if (US6 != 0x110000)
       Result.UnicodeScalars.push_back(US6);
     if (US7 != 0x110000)
       Result.UnicodeScalars.push_back(US7);
     return Result;
   }
 };
 
-std::pair<ConversionResult, std::vector<unsigned>>
+std::pair<ConversionResult, std::vector<unsigned long>>
 ConvertUTF8ToUnicodeScalarsLenient(StringRef S) {
   const UTF8 *SourceStart = reinterpret_cast<const UTF8 *>(S.data());
 
   const UTF8 *SourceNext = SourceStart;
   std::vector<UTF32> Decoded(S.size(), 0);
   UTF32 *TargetStart = Decoded.data();
 
   auto ErrorCode =
       ConvertUTF8toUTF32(&SourceNext, SourceStart + S.size(), &TargetStart,
                          Decoded.data() + Decoded.size(), lenientConversion);
 
   Decoded.resize(TargetStart - Decoded.data());
 
   return std::make_pair(ErrorCode, Decoded);
 }
 
-std::pair<ConversionResult, std::vector<unsigned>>
-ConvertUTF8ToUnicodeScalarsPartialLenient(StringRef S) {
-  const UTF8 *SourceStart = reinterpret_cast<const UTF8 *>(S.data());
-
-  const UTF8 *SourceNext = SourceStart;
-  std::vector<UTF32> Decoded(S.size(), 0);
-  UTF32 *TargetStart = Decoded.data();
+// std::pair<ConversionResult, std::vector<unsigned long>>
+// ConvertUTF8ToUnicodeScalarsPartialLenient(StringRef S) {
+//   const UTF8 *SourceStart = reinterpret_cast<const UTF8 *>(S.data());
+
+//   const UTF8 *SourceNext = SourceStart;
+//   std::vector<UTF32> Decoded(S.size(), 0);
+//   UTF32 *TargetStart = Decoded.data();
+
+//   auto ErrorCode = ConvertUTF8toUTF32Partial(
+//       &SourceNext, SourceStart + S.size(), &TargetStart,
+//       Decoded.data() + Decoded.size(), lenientConversion);
 
-  auto ErrorCode = ConvertUTF8toUTF32Partial(
-      &SourceNext, SourceStart + S.size(), &TargetStart,
-      Decoded.data() + Decoded.size(), lenientConversion);
-
-  Decoded.resize(TargetStart - Decoded.data());
+//   Decoded.resize(TargetStart - Decoded.data());
 
-  return std::make_pair(ErrorCode, Decoded);
-}
+//   return std::make_pair(ErrorCode, Decoded);
+// }
 
 ::testing::AssertionResult
 CheckConvertUTF8ToUnicodeScalars(ConvertUTFResultContainer Expected,
                                  StringRef S, bool Partial = false) {
   ConversionResult ErrorCode;
-  std::vector<unsigned> Decoded;
+  std::vector<unsigned long> Decoded;
   if (!Partial)
     std::tie(ErrorCode, Decoded) = ConvertUTF8ToUnicodeScalarsLenient(S);
-  else
-    std::tie(ErrorCode, Decoded) = ConvertUTF8ToUnicodeScalarsPartialLenient(S);
+//  else
+//    std::tie(ErrorCode, Decoded) = ConvertUTF8ToUnicodeScalarsPartialLenient(S);
 
   if (Expected.ErrorCode != ErrorCode)
     return ::testing::AssertionFailure() << "Expected error code "
                                          << Expected.ErrorCode << ", actual "
                                          << ErrorCode;
 
   if (Expected.UnicodeScalars != Decoded)
     return ::testing::AssertionFailure()