[llvm] r282822 - Move UTF functions into namespace llvm.

Justin Lebar via llvm-commits llvm-commits at lists.llvm.org
Thu Sep 29 17:38:46 PDT 2016


Author: jlebar
Date: Thu Sep 29 19:38:45 2016
New Revision: 282822

URL: http://llvm.org/viewvc/llvm-project?rev=282822&view=rev
Log:
Move UTF functions into namespace llvm.

Summary:
This lets people link against LLVM and their own version of the UTF
library.

I determined this only affects llvm, clang, lld, and lldb by running

$ git grep -wl 'UTF[0-9]\+\|\bConvertUTF\bisLegalUTF\|getNumBytesFor' | cut -f 1 -d '/' | sort | uniq
  clang
  lld
  lldb
  llvm

Tested with

  ninja lldb
  ninja check-clang check-llvm check-lld

(ninja check-lldb doesn't complete for me with or without this patch.)

Reviewers: rnk

Subscribers: klimek, beanz, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D24996

Added:
    llvm/trunk/lib/Support/ConvertUTF.cpp
Removed:
    llvm/trunk/lib/Support/ConvertUTF.c
Modified:
    llvm/trunk/include/llvm/Support/ConvertUTF.h
    llvm/trunk/lib/Support/CMakeLists.txt

Modified: llvm/trunk/include/llvm/Support/ConvertUTF.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/ConvertUTF.h?rev=282822&r1=282821&r2=282822&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/ConvertUTF.h (original)
+++ llvm/trunk/include/llvm/Support/ConvertUTF.h Thu Sep 29 19:38:45 2016
@@ -90,6 +90,14 @@
 #ifndef LLVM_SUPPORT_CONVERTUTF_H
 #define LLVM_SUPPORT_CONVERTUTF_H
 
+#include <string>
+#include <cstddef>
+
+// 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
@@ -127,11 +135,6 @@ typedef enum {
   lenientConversion
 } ConversionFlags;
 
-/* This is for C++ and does no harm in C */
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 ConversionResult ConvertUTF8toUTF16 (
   const UTF8** sourceStart, const UTF8* sourceEnd,
   UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
@@ -174,16 +177,9 @@ Boolean isLegalUTF8String(const UTF8 **s
 
 unsigned getNumBytesForUTF8(UTF8 firstByte);
 
-#ifdef __cplusplus
-}
-
 /*************************************************************************/
 /* Below are LLVM-specific wrappers of the functions above. */
 
-#include <string>
-#include <cstddef>
-
-namespace llvm {
 template <typename T> class ArrayRef;
 template <typename T> class SmallVectorImpl;
 class StringRef;
@@ -293,7 +289,3 @@ bool convertUTF8ToUTF16String(StringRef
 } /* end namespace llvm */
 
 #endif
-
-/* --------------------------------------------------------------------- */
-
-#endif

Modified: llvm/trunk/lib/Support/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/CMakeLists.txt?rev=282822&r1=282821&r2=282822&view=diff
==============================================================================
--- llvm/trunk/lib/Support/CMakeLists.txt (original)
+++ llvm/trunk/lib/Support/CMakeLists.txt Thu Sep 29 19:38:45 2016
@@ -40,7 +40,7 @@ add_llvm_library(LLVMSupport
   COM.cpp
   CommandLine.cpp
   Compression.cpp
-  ConvertUTF.c
+  ConvertUTF.cpp
   ConvertUTFWrapper.cpp
   CrashRecoveryContext.cpp
   DataExtractor.cpp

Removed: llvm/trunk/lib/Support/ConvertUTF.c
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/ConvertUTF.c?rev=282821&view=auto
==============================================================================
--- llvm/trunk/lib/Support/ConvertUTF.c (original)
+++ llvm/trunk/lib/Support/ConvertUTF.c (removed)
@@ -1,708 +0,0 @@
-/*===--- 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
-#include <assert.h>
-
-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);
-}
-
-/* --------------------------------------------------------------------- */
-
-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;
-}
-
-/* --------------------------------------------------------------------- */
-
-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;
-}
-
-/* --------------------------------------------------------------------- */
-
-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;
-        }
-
-        /* 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];
-
-        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;
-}
-
-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.
-
-   --------------------------------------------------------------------- */

Added: llvm/trunk/lib/Support/ConvertUTF.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/ConvertUTF.cpp?rev=282822&view=auto
==============================================================================
--- llvm/trunk/lib/Support/ConvertUTF.cpp (added)
+++ llvm/trunk/lib/Support/ConvertUTF.cpp Thu Sep 29 19:38:45 2016
@@ -0,0 +1,710 @@
+/*===--- 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
+#include <assert.h>
+
+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.
+ */
+
+
+/* --------------------------------------------------------------------- */
+
+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);
+}
+
+/* --------------------------------------------------------------------- */
+
+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;
+}
+
+/* --------------------------------------------------------------------- */
+
+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;
+}
+
+/* --------------------------------------------------------------------- */
+
+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;
+        }
+
+        /* 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];
+
+        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;
+}
+
+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.
+
+   --------------------------------------------------------------------- */
+
+} // namespace llvm




More information about the llvm-commits mailing list