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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
16  * kind are expressed or implied. The recipient agrees to determine
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 #include <cstddef>
94 #include <string>
95 
96 // Wrap everything in namespace llvm so that programs can link with llvm and
97 // their own version of the unicode libraries.
98 
99 namespace llvm {
100 
101 /* ---------------------------------------------------------------------
102  The following 4 definitions are compiler-specific.
103  The C standard does not guarantee that wchar_t has at least
104  16 bits, so wchar_t is no less portable than unsigned short!
105  All should be unsigned values to avoid sign extension during
106  bit mask & shift operations.
107 ------------------------------------------------------------------------ */
108 
109 typedef unsigned int UTF32; /* at least 32 bits */
110 typedef unsigned short UTF16; /* at least 16 bits */
111 typedef unsigned char UTF8; /* typically 8 bits */
112 typedef unsigned char Boolean; /* 0 or 1 */
113 
114 /* Some fundamental constants */
115 #define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD
116 #define UNI_MAX_BMP (UTF32)0x0000FFFF
117 #define UNI_MAX_UTF16 (UTF32)0x0010FFFF
118 #define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF
119 #define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF
120 
121 #define UNI_MAX_UTF8_BYTES_PER_CODE_POINT 4
122 
123 #define UNI_UTF16_BYTE_ORDER_MARK_NATIVE 0xFEFF
124 #define UNI_UTF16_BYTE_ORDER_MARK_SWAPPED 0xFFFE
125 
126 typedef enum {
127  conversionOK, /* conversion successful */
128  sourceExhausted, /* partial character in source, but hit end */
129  targetExhausted, /* insuff. room in target for conversion */
130  sourceIllegal /* source sequence is illegal/malformed */
132 
133 typedef enum {
137 
138 ConversionResult ConvertUTF8toUTF16 (
139  const UTF8** sourceStart, const UTF8* sourceEnd,
140  UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
141 
142 /**
143  * Convert a partial UTF8 sequence to UTF32. If the sequence ends in an
144  * incomplete code unit sequence, returns \c sourceExhausted.
145  */
146 ConversionResult ConvertUTF8toUTF32Partial(
147  const UTF8** sourceStart, const UTF8* sourceEnd,
148  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
149 
150 /**
151  * Convert a partial UTF8 sequence to UTF32. If the sequence ends in an
152  * incomplete code unit sequence, returns \c sourceIllegal.
153  */
154 ConversionResult ConvertUTF8toUTF32(
155  const UTF8** sourceStart, const UTF8* sourceEnd,
156  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
157 
158 ConversionResult ConvertUTF16toUTF8 (
159  const UTF16** sourceStart, const UTF16* sourceEnd,
160  UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
161 
162 ConversionResult ConvertUTF32toUTF8 (
163  const UTF32** sourceStart, const UTF32* sourceEnd,
164  UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
165 
166 ConversionResult ConvertUTF16toUTF32 (
167  const UTF16** sourceStart, const UTF16* sourceEnd,
168  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
169 
170 ConversionResult ConvertUTF32toUTF16 (
171  const UTF32** sourceStart, const UTF32* sourceEnd,
172  UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
173 
174 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd);
175 
176 Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd);
177 
178 unsigned getNumBytesForUTF8(UTF8 firstByte);
179 
180 /*************************************************************************/
181 /* Below are LLVM-specific wrappers of the functions above. */
182 
183 template <typename T> class ArrayRef;
184 template <typename T> class SmallVectorImpl;
185 class StringRef;
186 
187 /**
188  * Convert an UTF8 StringRef to UTF8, UTF16, or UTF32 depending on
189  * WideCharWidth. The converted data is written to ResultPtr, which needs to
190  * point to at least WideCharWidth * (Source.Size() + 1) bytes. On success,
191  * ResultPtr will point one after the end of the copied string. On failure,
192  * ResultPtr will not be changed, and ErrorPtr will be set to the location of
193  * the first character which could not be converted.
194  * \return true on success.
195  */
196 bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source,
197  char *&ResultPtr, const UTF8 *&ErrorPtr);
198 
199 /**
200 * Converts a UTF-8 StringRef to a std::wstring.
201 * \return true on success.
202 */
203 bool ConvertUTF8toWide(llvm::StringRef Source, std::wstring &Result);
204 
205 /**
206 * Converts a UTF-8 C-string to a std::wstring.
207 * \return true on success.
208 */
209 bool ConvertUTF8toWide(const char *Source, std::wstring &Result);
210 
211 /**
212 * Converts a std::wstring to a UTF-8 encoded std::string.
213 * \return true on success.
214 */
215 bool convertWideToUTF8(const std::wstring &Source, std::string &Result);
216 
217 
218 /**
219  * Convert an Unicode code point to UTF8 sequence.
220  *
221  * \param Source a Unicode code point.
222  * \param [in,out] ResultPtr pointer to the output buffer, needs to be at least
223  * \c UNI_MAX_UTF8_BYTES_PER_CODE_POINT bytes. On success \c ResultPtr is
224  * updated one past end of the converted sequence.
225  *
226  * \returns true on success.
227  */
228 bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr);
229 
230 /**
231  * Convert the first UTF8 sequence in the given source buffer to a UTF32
232  * code point.
233  *
234  * \param [in,out] source A pointer to the source buffer. If the conversion
235  * succeeds, this pointer will be updated to point to the byte just past the
236  * end of the converted sequence.
237  * \param sourceEnd A pointer just past the end of the source buffer.
238  * \param [out] target The converted code
239  * \param flags Whether the conversion is strict or lenient.
240  *
241  * \returns conversionOK on success
242  *
243  * \sa ConvertUTF8toUTF32
244  */
245 inline ConversionResult convertUTF8Sequence(const UTF8 **source,
246  const UTF8 *sourceEnd,
247  UTF32 *target,
248  ConversionFlags flags) {
249  if (*source == sourceEnd)
250  return sourceExhausted;
251  unsigned size = getNumBytesForUTF8(**source);
252  if ((ptrdiff_t)size > sourceEnd - *source)
253  return sourceExhausted;
254  return ConvertUTF8toUTF32(source, *source + size, &target, target + 1, flags);
255 }
256 
257 /**
258  * Returns true if a blob of text starts with a UTF-16 big or little endian byte
259  * order mark.
260  */
262 
263 /**
264  * Converts a stream of raw bytes assumed to be UTF16 into a UTF8 std::string.
265  *
266  * \param [in] SrcBytes A buffer of what is assumed to be UTF-16 encoded text.
267  * \param [out] Out Converted UTF-8 is stored here on success.
268  * \returns true on success
269  */
270 bool convertUTF16ToUTF8String(ArrayRef<char> SrcBytes, std::string &Out);
271 
272 /**
273 * Converts a UTF16 string into a UTF8 std::string.
274 *
275 * \param [in] Src A buffer of UTF-16 encoded text.
276 * \param [out] Out Converted UTF-8 is stored here on success.
277 * \returns true on success
278 */
279 bool convertUTF16ToUTF8String(ArrayRef<UTF16> Src, std::string &Out);
280 
281 /**
282  * Converts a UTF-8 string into a UTF-16 string with native endianness.
283  *
284  * \returns true on success
285  */
287  SmallVectorImpl<UTF16> &DstUTF16);
288 
289 } /* end namespace llvm */
290 
291 #endif
unsigned int UTF32
Definition: ConvertUTF.h:109
bool hasUTF16ByteOrderMark(ArrayRef< char > SrcBytes)
Returns true if a blob of text starts with a UTF-16 big or little endian byte order mark...
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
ConversionResult
Definition: ConvertUTF.h:126
unsigned short UTF16
Definition: ConvertUTF.h:110
ConversionResult ConvertUTF8toUTF32(const UTF8 **sourceStart, const UTF8 *sourceEnd, UTF32 **targetStart, UTF32 *targetEnd, ConversionFlags flags)
Convert a partial UTF8 sequence to UTF32.
Definition: ConvertUTF.cpp:711
ConversionResult ConvertUTF16toUTF8(const UTF16 **sourceStart, const UTF16 *sourceEnd, UTF8 **targetStart, UTF8 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.cpp:248
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:42
ConversionResult ConvertUTF32toUTF16(const UTF32 **sourceStart, const UTF32 *sourceEnd, UTF16 **targetStart, UTF16 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.cpp:145
unsigned char UTF8
Definition: ConvertUTF.h:111
bool convertWideToUTF8(const std::wstring &Source, std::string &Result)
Converts a std::wstring to a UTF-8 encoded std::string.
unsigned getNumBytesForUTF8(UTF8 firstByte)
Definition: ConvertUTF.cpp:520
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
bool convertUTF8ToUTF16String(StringRef SrcUTF8, SmallVectorImpl< UTF16 > &DstUTF16)
Converts a UTF-8 string into a UTF-16 string with native endianness.
ConversionResult ConvertUTF8toUTF16(const UTF8 **sourceStart, const UTF8 *sourceEnd, UTF16 **targetStart, UTF16 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.cpp:542
ConversionResult ConvertUTF32toUTF8(const UTF32 **sourceStart, const UTF32 *sourceEnd, UTF8 **targetStart, UTF8 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.cpp:318
bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source, char *&ResultPtr, const UTF8 *&ErrorPtr)
Convert an UTF8 StringRef to UTF8, UTF16, or UTF32 depending on WideCharWidth.
Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd)
Definition: ConvertUTF.cpp:413
bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr)
Convert an Unicode code point to UTF8 sequence.
Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd)
Definition: ConvertUTF.cpp:530
ConversionResult ConvertUTF8toUTF32Partial(const UTF8 **sourceStart, const UTF8 *sourceEnd, UTF32 **targetStart, UTF32 *targetEnd, ConversionFlags flags)
Convert a partial UTF8 sequence to UTF32.
Definition: ConvertUTF.cpp:702
unsigned char Boolean
Definition: ConvertUTF.h:112
ConversionResult convertUTF8Sequence(const UTF8 **source, const UTF8 *sourceEnd, UTF32 *target, ConversionFlags flags)
Convert the first UTF8 sequence in the given source buffer to a UTF32 code point. ...
Definition: ConvertUTF.h:245
ConversionFlags
Definition: ConvertUTF.h:133
ConversionResult ConvertUTF16toUTF32(const UTF16 **sourceStart, const UTF16 *sourceEnd, UTF32 **targetStart, UTF32 *targetEnd, ConversionFlags flags)
Definition: ConvertUTF.cpp:194
bool convertUTF16ToUTF8String(ArrayRef< char > SrcBytes, std::string &Out)
Converts a stream of raw bytes assumed to be UTF16 into a UTF8 std::string.
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49