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
18 * purchased on magnetic or optical media from Unicode, Inc., the
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 */
123 } ConversionResult;
124
125 typedef enum {
126 strictConversion = 0,
127 lenientConversion
128 } ConversionFlags;
129
130 /* This is for C++ and does no harm in C */
131 #ifdef __cplusplus
132 extern "C" {
133 #endif
134
135 ConversionResult ConvertUTF8toUTF16 (
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 */
143 ConversionResult ConvertUTF8toUTF32Partial(
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 */
151 ConversionResult ConvertUTF8toUTF32(
152 const UTF8** sourceStart, const UTF8* sourceEnd,
153 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
154
155 ConversionResult ConvertUTF16toUTF8 (
156 const UTF16** sourceStart, const UTF16* sourceEnd,
157 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
158
159 ConversionResult ConvertUTF32toUTF8 (
160 const UTF32** sourceStart, const UTF32* sourceEnd,
161 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
162
163 ConversionResult ConvertUTF16toUTF32 (
164 const UTF16** sourceStart, const UTF16* sourceEnd,
165 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
166
167 ConversionResult ConvertUTF32toUTF16 (
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 */
convertUTF8Sequence(const UTF8 ** source,const UTF8 * sourceEnd,UTF32 * target,ConversionFlags flags)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
269