LLVM  3.7.0
ConvertUTF.h
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1 /*===--- ConvertUTF.h - Universal Character Names conversions ---------------===
2  *
3  * The LLVM Compiler Infrastructure
4  *
5  * This file is distributed under the University of Illinois Open Source
6  * License. See LICENSE.TXT for details.
7  *
8  *==------------------------------------------------------------------------==*/
9 /*
10  * Copyright 2001-2004 Unicode, Inc.
11  *
12  * Disclaimer
13  *
14  * This source code is provided as is by Unicode, Inc. No claims are
15  * made as to fitness for any particular purpose. No warranties of any
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17  * applicability of information provided. If this file has been
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19  * sole remedy for any claim will be exchange of defective media
20  * within 90 days of receipt.
21  *
22  * Limitations on Rights to Redistribute This Code
23  *
24  * Unicode, Inc. hereby grants the right to freely use the information
25  * supplied in this file in the creation of products supporting the
26  * Unicode Standard, and to make copies of this file in any form
27  * for internal or external distribution as long as this notice
28  * remains attached.
29  */
30 
31 /* ---------------------------------------------------------------------
32 
33  Conversions between UTF32, UTF-16, and UTF-8. Header file.
34 
35  Several funtions are included here, forming a complete set of
36  conversions between the three formats. UTF-7 is not included
37  here, but is handled in a separate source file.
38 
39  Each of these routines takes pointers to input buffers and output
40  buffers. The input buffers are const.
41 
42  Each routine converts the text between *sourceStart and sourceEnd,
43  putting the result into the buffer between *targetStart and
44  targetEnd. Note: the end pointers are *after* the last item: e.g.
45  *(sourceEnd - 1) is the last item.
46 
47  The return result indicates whether the conversion was successful,
48  and if not, whether the problem was in the source or target buffers.
49  (Only the first encountered problem is indicated.)
50 
51  After the conversion, *sourceStart and *targetStart are both
52  updated to point to the end of last text successfully converted in
53  the respective buffers.
54 
55  Input parameters:
56  sourceStart - pointer to a pointer to the source buffer.
57  The contents of this are modified on return so that
58  it points at the next thing to be converted.
59  targetStart - similarly, pointer to pointer to the target buffer.
60  sourceEnd, targetEnd - respectively pointers to the ends of the
61  two buffers, for overflow checking only.
62 
63  These conversion functions take a ConversionFlags argument. When this
64  flag is set to strict, both irregular sequences and isolated surrogates
65  will cause an error. When the flag is set to lenient, both irregular
66  sequences and isolated surrogates are converted.
67 
68  Whether the flag is strict or lenient, all illegal sequences will cause
69  an error return. This includes sequences such as: <F4 90 80 80>, <C0 80>,
70  or <A0> in UTF-8, and values above 0x10FFFF in UTF-32. Conformant code
71  must check for illegal sequences.
72 
73  When the flag is set to lenient, characters over 0x10FFFF are converted
74  to the replacement character; otherwise (when the flag is set to strict)
75  they constitute an error.
76 
77  Output parameters:
78  The value "sourceIllegal" is returned from some routines if the input
79  sequence is malformed. When "sourceIllegal" is returned, the source
80  value will point to the illegal value that caused the problem. E.g.,
81  in UTF-8 when a sequence is malformed, it points to the start of the
82  malformed sequence.
83 
84  Author: Mark E. Davis, 1994.
85  Rev History: Rick McGowan, fixes & updates May 2001.
86  Fixes & updates, Sept 2001.
87 
88 ------------------------------------------------------------------------ */
89 
90 #ifndef LLVM_SUPPORT_CONVERTUTF_H
91 #define LLVM_SUPPORT_CONVERTUTF_H
92 
93 /* ---------------------------------------------------------------------
94  The following 4 definitions are compiler-specific.
95  The C standard does not guarantee that wchar_t has at least
96  16 bits, so wchar_t is no less portable than unsigned short!
97  All should be unsigned values to avoid sign extension during
98  bit mask & shift operations.
99 ------------------------------------------------------------------------ */
100 
101 typedef unsigned int UTF32; /* at least 32 bits */
102 typedef unsigned short UTF16; /* at least 16 bits */
103 typedef unsigned char UTF8; /* typically 8 bits */
104 typedef unsigned char Boolean; /* 0 or 1 */
105 
106 /* Some fundamental constants */
107 #define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD
108 #define UNI_MAX_BMP (UTF32)0x0000FFFF
109 #define UNI_MAX_UTF16 (UTF32)0x0010FFFF
110 #define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF
111 #define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF
112 
113 #define UNI_MAX_UTF8_BYTES_PER_CODE_POINT 4
114 
115 #define UNI_UTF16_BYTE_ORDER_MARK_NATIVE 0xFEFF
116 #define UNI_UTF16_BYTE_ORDER_MARK_SWAPPED 0xFFFE
117 
118 typedef enum {
119  conversionOK, /* conversion successful */
120  sourceExhausted, /* partial character in source, but hit end */
121  targetExhausted, /* insuff. room in target for conversion */
122  sourceIllegal /* source sequence is illegal/malformed */
124 
125 typedef enum {
129 
130 /* This is for C++ and does no harm in C */
131 #ifdef __cplusplus
132 extern "C" {
133 #endif
134 
136  const UTF8** sourceStart, const UTF8* sourceEnd,
137  UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
138 
139 /**
140  * Convert a partial UTF8 sequence to UTF32. If the sequence ends in an
141  * incomplete code unit sequence, returns \c sourceExhausted.
142  */
144  const UTF8** sourceStart, const UTF8* sourceEnd,
145  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
146 
147 /**
148  * Convert a partial UTF8 sequence to UTF32. If the sequence ends in an
149  * incomplete code unit sequence, returns \c sourceIllegal.
150  */
152  const UTF8** sourceStart, const UTF8* sourceEnd,
153  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
154 
156  const UTF16** sourceStart, const UTF16* sourceEnd,
157  UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
158 
160  const UTF32** sourceStart, const UTF32* sourceEnd,
161  UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
162 
164  const UTF16** sourceStart, const UTF16* sourceEnd,
165  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
166 
168  const UTF32** sourceStart, const UTF32* sourceEnd,
169  UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
170 
171 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd);
172 
173 Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd);
174 
175 unsigned getNumBytesForUTF8(UTF8 firstByte);
176 
177 #ifdef __cplusplus
178 }
179 
180 /*************************************************************************/
181 /* Below are LLVM-specific wrappers of the functions above. */
182 
183 #include "llvm/ADT/ArrayRef.h"
184 #include "llvm/ADT/StringRef.h"
185 
186 namespace llvm {
187 
188 /**
189  * Convert an UTF8 StringRef to UTF8, UTF16, or UTF32 depending on
190  * WideCharWidth. The converted data is written to ResultPtr, which needs to
191  * point to at least WideCharWidth * (Source.Size() + 1) bytes. On success,
192  * ResultPtr will point one after the end of the copied string. On failure,
193  * ResultPtr will not be changed, and ErrorPtr will be set to the location of
194  * the first character which could not be converted.
195  * \return true on success.
196  */
197 bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source,
198  char *&ResultPtr, const UTF8 *&ErrorPtr);
199 
200 /**
201  * Convert an Unicode code point to UTF8 sequence.
202  *
203  * \param Source a Unicode code point.
204  * \param [in,out] ResultPtr pointer to the output buffer, needs to be at least
205  * \c UNI_MAX_UTF8_BYTES_PER_CODE_POINT bytes. On success \c ResultPtr is
206  * updated one past end of the converted sequence.
207  *
208  * \returns true on success.
209  */
210 bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr);
211 
212 /**
213  * Convert the first UTF8 sequence in the given source buffer to a UTF32
214  * code point.
215  *
216  * \param [in,out] source A pointer to the source buffer. If the conversion
217  * succeeds, this pointer will be updated to point to the byte just past the
218  * end of the converted sequence.
219  * \param sourceEnd A pointer just past the end of the source buffer.
220  * \param [out] target The converted code
221  * \param flags Whether the conversion is strict or lenient.
222  *
223  * \returns conversionOK on success
224  *
225  * \sa ConvertUTF8toUTF32
226  */
227 static inline ConversionResult convertUTF8Sequence(const UTF8 **source,
228  const UTF8 *sourceEnd,
229  UTF32 *target,
230  ConversionFlags flags) {
231  if (*source == sourceEnd)
232  return sourceExhausted;
233  unsigned size = getNumBytesForUTF8(**source);
234  if ((ptrdiff_t)size > sourceEnd - *source)
235  return sourceExhausted;
236  return ConvertUTF8toUTF32(source, *source + size, &target, target + 1, flags);
237 }
238 
239 /**
240  * Returns true if a blob of text starts with a UTF-16 big or little endian byte
241  * order mark.
242  */
243 bool hasUTF16ByteOrderMark(ArrayRef<char> SrcBytes);
244 
245 /**
246  * Converts a stream of raw bytes assumed to be UTF16 into a UTF8 std::string.
247  *
248  * \param [in] SrcBytes A buffer of what is assumed to be UTF-16 encoded text.
249  * \param [out] Out Converted UTF-8 is stored here on success.
250  * \returns true on success
251  */
252 bool convertUTF16ToUTF8String(ArrayRef<char> SrcBytes, std::string &Out);
253 
254 /**
255  * Converts a UTF-8 string into a UTF-16 string with native endianness.
256  *
257  * \returns true on success
258  */
259 bool convertUTF8ToUTF16String(StringRef SrcUTF8,
260  SmallVectorImpl<UTF16> &DstUTF16);
261 
262 } /* end namespace llvm */
263 
264 #endif
265 
266 /* --------------------------------------------------------------------- */
267 
268 #endif
ConversionResult ConvertUTF32toUTF8(const UTF32 **sourceStart, const UTF32 *sourceEnd, UTF8 **targetStart, UTF8 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.c:291
ConversionResult ConvertUTF16toUTF32(const UTF16 **sourceStart, const UTF16 *sourceEnd, UTF32 **targetStart, UTF32 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.c:167
Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd)
Definition: ConvertUTF.c:386
ConversionResult ConvertUTF16toUTF8(const UTF16 **sourceStart, const UTF16 *sourceEnd, UTF8 **targetStart, UTF8 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.c:221
Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd)
Definition: ConvertUTF.c:503
ConversionResult
Definition: ConvertUTF.h:118
unsigned getNumBytesForUTF8(UTF8 firstByte)
Definition: ConvertUTF.c:493
ConversionResult ConvertUTF32toUTF16(const UTF32 **sourceStart, const UTF32 *sourceEnd, UTF16 **targetStart, UTF16 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.c:118
bool convertUTF8ToUTF16String(StringRef SrcUTF8, SmallVectorImpl< UTF16 > &DstUTF16)
unsigned char UTF8
Definition: ConvertUTF.h:103
bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source, char *&ResultPtr, const UTF8 *&ErrorPtr)
bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr)
unsigned short UTF16
Definition: ConvertUTF.h:102
unsigned char Boolean
Definition: ConvertUTF.h:104
ConversionResult ConvertUTF8toUTF32Partial(const UTF8 **sourceStart, const UTF8 *sourceEnd, UTF32 **targetStart, UTF32 *targetEnd, ConversionFlags flags)
Convert a partial UTF8 sequence to UTF32.
Definition: ConvertUTF.c:675
ConversionResult ConvertUTF8toUTF32(const UTF8 **sourceStart, const UTF8 *sourceEnd, UTF32 **targetStart, UTF32 *targetEnd, ConversionFlags flags)
Convert a partial UTF8 sequence to UTF32.
Definition: ConvertUTF.c:684
unsigned int UTF32
Definition: ConvertUTF.h:101
bool convertUTF16ToUTF8String(ArrayRef< char > SrcBytes, std::string &Out)
ConversionFlags
Definition: ConvertUTF.h:125
void size_t size
ConversionResult ConvertUTF8toUTF16(const UTF8 **sourceStart, const UTF8 *sourceEnd, UTF16 **targetStart, UTF16 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.c:515
bool hasUTF16ByteOrderMark(ArrayRef< char > S)
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:40