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 CLANG_BASIC_CONVERTUTF_H
91#define CLANG_BASIC_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
101typedef unsigned int    UTF32;  /* at least 32 bits */
102typedef unsigned short  UTF16;  /* at least 16 bits */
103typedef unsigned char   UTF8;   /* typically 8 bits */
104typedef 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
115typedef enum {
116  conversionOK,           /* conversion successful */
117  sourceExhausted,        /* partial character in source, but hit end */
118  targetExhausted,        /* insuff. room in target for conversion */
119  sourceIllegal           /* source sequence is illegal/malformed */
120} ConversionResult;
121
122typedef enum {
123  strictConversion = 0,
124  lenientConversion
125} ConversionFlags;
126
127/* This is for C++ and does no harm in C */
128#ifdef __cplusplus
129extern "C" {
130#endif
131
132ConversionResult ConvertUTF8toUTF16 (
133  const UTF8** sourceStart, const UTF8* sourceEnd,
134  UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
135
136ConversionResult ConvertUTF8toUTF32 (
137  const UTF8** sourceStart, const UTF8* sourceEnd,
138  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
139
140ConversionResult ConvertUTF16toUTF8 (
141  const UTF16** sourceStart, const UTF16* sourceEnd,
142  UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
143
144ConversionResult ConvertUTF32toUTF8 (
145  const UTF32** sourceStart, const UTF32* sourceEnd,
146  UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
147
148ConversionResult ConvertUTF16toUTF32 (
149  const UTF16** sourceStart, const UTF16* sourceEnd,
150  UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
151
152ConversionResult ConvertUTF32toUTF16 (
153  const UTF32** sourceStart, const UTF32* sourceEnd,
154  UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
155
156Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd);
157
158Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd);
159
160unsigned getNumBytesForUTF8(UTF8 firstByte);
161
162#ifdef __cplusplus
163}
164
165/*************************************************************************/
166/* Below are LLVM-specific wrappers of the functions above. */
167
168#include "llvm/ADT/StringRef.h"
169
170namespace llvm {
171
172/**
173 * Convert an UTF8 StringRef to UTF8, UTF16, or UTF32 depending on
174 * WideCharWidth. The converted data is written to ResultPtr, which needs to
175 * point to at least WideCharWidth * (Source.Size() + 1) bytes. On success,
176 * ResultPtr will point one after the end of the copied string. On failure,
177 * ResultPtr will not be changed, and ErrorPtr will be set to the location of
178 * the first character which could not be converted.
179 * \return true on success.
180 */
181bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source,
182                       char *&ResultPtr, const UTF8 *&ErrorPtr);
183
184/**
185 * Convert an Unicode code point to UTF8 sequence.
186 *
187 * \param Source a Unicode code point.
188 * \param [in,out] ResultPtr pointer to the output buffer, needs to be at least
189 * \c UNI_MAX_UTF8_BYTES_PER_CODE_POINT bytes.  On success \c ResultPtr is
190 * updated one past end of the converted sequence.
191 *
192 * \returns true on success.
193 */
194bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr);
195
196/**
197 * Convert the first UTF8 sequence in the given source buffer to a UTF32
198 * code point.
199 *
200 * \param [in,out] source A pointer to the source buffer. If the conversion
201 * succeeds, this pointer will be updated to point to the byte just past the
202 * end of the converted sequence.
203 * \param sourceEnd A pointer just past the end of the source buffer.
204 * \param [out] target The converted code
205 * \param flags Whether the conversion is strict or lenient.
206 *
207 * \returns conversionOK on success
208 *
209 * \sa ConvertUTF8toUTF32
210 */
211static inline ConversionResult convertUTF8Sequence(const UTF8 **source,
212                                                   const UTF8 *sourceEnd,
213                                                   UTF32 *target,
214                                                   ConversionFlags flags) {
215  if (*source == sourceEnd)
216    return sourceExhausted;
217  unsigned size = getNumBytesForUTF8(**source);
218  if ((ptrdiff_t)size > sourceEnd - *source)
219    return sourceExhausted;
220  return ConvertUTF8toUTF32(source, *source + size, &target, target + 1, flags);
221}
222} /* end namespace llvm */
223
224#endif
225
226/* --------------------------------------------------------------------- */
227
228#endif
229