1 //===-- ConvertUTFWrapper.cpp - Wrap ConvertUTF.h with clang data types -----===
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "llvm/ADT/ArrayRef.h"
10 #include "llvm/ADT/StringRef.h"
11 #include "llvm/Support/ConvertUTF.h"
12 #include "llvm/Support/ErrorHandling.h"
13 #include "llvm/Support/SwapByteOrder.h"
14 #include <string>
15 #include <vector>
16
17 namespace llvm {
18
ConvertUTF8toWide(unsigned WideCharWidth,llvm::StringRef Source,char * & ResultPtr,const UTF8 * & ErrorPtr)19 bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source,
20 char *&ResultPtr, const UTF8 *&ErrorPtr) {
21 assert(WideCharWidth == 1 || WideCharWidth == 2 || WideCharWidth == 4);
22 ConversionResult result = conversionOK;
23 // Copy the character span over.
24 if (WideCharWidth == 1) {
25 const UTF8 *Pos = reinterpret_cast<const UTF8*>(Source.begin());
26 if (!isLegalUTF8String(&Pos, reinterpret_cast<const UTF8*>(Source.end()))) {
27 result = sourceIllegal;
28 ErrorPtr = Pos;
29 } else {
30 memcpy(ResultPtr, Source.data(), Source.size());
31 ResultPtr += Source.size();
32 }
33 } else if (WideCharWidth == 2) {
34 const UTF8 *sourceStart = (const UTF8*)Source.data();
35 // FIXME: Make the type of the result buffer correct instead of
36 // using reinterpret_cast.
37 UTF16 *targetStart = reinterpret_cast<UTF16 *>(ResultPtr);
38 ConversionFlags flags = strictConversion;
39 result =
40 ConvertUTF8toUTF16(&sourceStart, sourceStart + Source.size(),
41 &targetStart, targetStart + Source.size(), flags);
42 if (result == conversionOK)
43 ResultPtr = reinterpret_cast<char *>(targetStart);
44 else
45 ErrorPtr = sourceStart;
46 } else if (WideCharWidth == 4) {
47 const UTF8 *sourceStart = (const UTF8 *)Source.data();
48 // FIXME: Make the type of the result buffer correct instead of
49 // using reinterpret_cast.
50 UTF32 *targetStart = reinterpret_cast<UTF32 *>(ResultPtr);
51 ConversionFlags flags = strictConversion;
52 result =
53 ConvertUTF8toUTF32(&sourceStart, sourceStart + Source.size(),
54 &targetStart, targetStart + Source.size(), flags);
55 if (result == conversionOK)
56 ResultPtr = reinterpret_cast<char *>(targetStart);
57 else
58 ErrorPtr = sourceStart;
59 }
60 assert((result != targetExhausted) &&
61 "ConvertUTF8toUTFXX exhausted target buffer");
62 return result == conversionOK;
63 }
64
ConvertCodePointToUTF8(unsigned Source,char * & ResultPtr)65 bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr) {
66 const UTF32 *SourceStart = &Source;
67 const UTF32 *SourceEnd = SourceStart + 1;
68 UTF8 *TargetStart = reinterpret_cast<UTF8 *>(ResultPtr);
69 UTF8 *TargetEnd = TargetStart + 4;
70 ConversionResult CR = ConvertUTF32toUTF8(
71 &SourceStart, SourceEnd, &TargetStart, TargetEnd, strictConversion);
72 if (CR != conversionOK)
73 return false;
74
75 ResultPtr = reinterpret_cast<char *>(TargetStart);
76 return true;
77 }
78
hasUTF16ByteOrderMark(ArrayRef<char> S)79 bool hasUTF16ByteOrderMark(ArrayRef<char> S) {
80 return (S.size() >= 2 && ((S[0] == '\xff' && S[1] == '\xfe') ||
81 (S[0] == '\xfe' && S[1] == '\xff')));
82 }
83
convertUTF16ToUTF8String(ArrayRef<char> SrcBytes,std::string & Out)84 bool convertUTF16ToUTF8String(ArrayRef<char> SrcBytes, std::string &Out) {
85 assert(Out.empty());
86
87 // Error out on an uneven byte count.
88 if (SrcBytes.size() % 2)
89 return false;
90
91 // Avoid OOB by returning early on empty input.
92 if (SrcBytes.empty())
93 return true;
94
95 const UTF16 *Src = reinterpret_cast<const UTF16 *>(SrcBytes.begin());
96 const UTF16 *SrcEnd = reinterpret_cast<const UTF16 *>(SrcBytes.end());
97
98 assert((uintptr_t)Src % sizeof(UTF16) == 0);
99
100 // Byteswap if necessary.
101 std::vector<UTF16> ByteSwapped;
102 if (Src[0] == UNI_UTF16_BYTE_ORDER_MARK_SWAPPED) {
103 ByteSwapped.insert(ByteSwapped.end(), Src, SrcEnd);
104 for (UTF16 &I : ByteSwapped)
105 I = llvm::byteswap<uint16_t>(I);
106 Src = &ByteSwapped[0];
107 SrcEnd = &ByteSwapped[ByteSwapped.size() - 1] + 1;
108 }
109
110 // Skip the BOM for conversion.
111 if (Src[0] == UNI_UTF16_BYTE_ORDER_MARK_NATIVE)
112 Src++;
113
114 // Just allocate enough space up front. We'll shrink it later. Allocate
115 // enough that we can fit a null terminator without reallocating.
116 Out.resize(SrcBytes.size() * UNI_MAX_UTF8_BYTES_PER_CODE_POINT + 1);
117 UTF8 *Dst = reinterpret_cast<UTF8 *>(&Out[0]);
118 UTF8 *DstEnd = Dst + Out.size();
119
120 ConversionResult CR =
121 ConvertUTF16toUTF8(&Src, SrcEnd, &Dst, DstEnd, strictConversion);
122 assert(CR != targetExhausted);
123
124 if (CR != conversionOK) {
125 Out.clear();
126 return false;
127 }
128
129 Out.resize(reinterpret_cast<char *>(Dst) - &Out[0]);
130 Out.push_back(0);
131 Out.pop_back();
132 return true;
133 }
134
convertUTF16ToUTF8String(ArrayRef<UTF16> Src,std::string & Out)135 bool convertUTF16ToUTF8String(ArrayRef<UTF16> Src, std::string &Out) {
136 return convertUTF16ToUTF8String(
137 llvm::ArrayRef<char>(reinterpret_cast<const char *>(Src.data()),
138 Src.size() * sizeof(UTF16)),
139 Out);
140 }
141
convertUTF32ToUTF8String(ArrayRef<char> SrcBytes,std::string & Out)142 bool convertUTF32ToUTF8String(ArrayRef<char> SrcBytes, std::string &Out) {
143 assert(Out.empty());
144
145 // Error out on an uneven byte count.
146 if (SrcBytes.size() % 4)
147 return false;
148
149 // Avoid OOB by returning early on empty input.
150 if (SrcBytes.empty())
151 return true;
152
153 const UTF32 *Src = reinterpret_cast<const UTF32 *>(SrcBytes.begin());
154 const UTF32 *SrcEnd = reinterpret_cast<const UTF32 *>(SrcBytes.end());
155
156 assert((uintptr_t)Src % sizeof(UTF32) == 0);
157
158 // Byteswap if necessary.
159 std::vector<UTF32> ByteSwapped;
160 if (Src[0] == UNI_UTF32_BYTE_ORDER_MARK_SWAPPED) {
161 ByteSwapped.insert(ByteSwapped.end(), Src, SrcEnd);
162 for (UTF32 &I : ByteSwapped)
163 I = llvm::byteswap<uint32_t>(I);
164 Src = &ByteSwapped[0];
165 SrcEnd = &ByteSwapped[ByteSwapped.size() - 1] + 1;
166 }
167
168 // Skip the BOM for conversion.
169 if (Src[0] == UNI_UTF32_BYTE_ORDER_MARK_NATIVE)
170 Src++;
171
172 // Just allocate enough space up front. We'll shrink it later. Allocate
173 // enough that we can fit a null terminator without reallocating.
174 Out.resize(SrcBytes.size() * UNI_MAX_UTF8_BYTES_PER_CODE_POINT + 1);
175 UTF8 *Dst = reinterpret_cast<UTF8 *>(&Out[0]);
176 UTF8 *DstEnd = Dst + Out.size();
177
178 ConversionResult CR =
179 ConvertUTF32toUTF8(&Src, SrcEnd, &Dst, DstEnd, strictConversion);
180 assert(CR != targetExhausted);
181
182 if (CR != conversionOK) {
183 Out.clear();
184 return false;
185 }
186
187 Out.resize(reinterpret_cast<char *>(Dst) - &Out[0]);
188 Out.push_back(0);
189 Out.pop_back();
190 return true;
191 }
192
convertUTF32ToUTF8String(ArrayRef<UTF32> Src,std::string & Out)193 bool convertUTF32ToUTF8String(ArrayRef<UTF32> Src, std::string &Out) {
194 return convertUTF32ToUTF8String(
195 llvm::ArrayRef<char>(reinterpret_cast<const char *>(Src.data()),
196 Src.size() * sizeof(UTF32)),
197 Out);
198 }
199
convertUTF8ToUTF16String(StringRef SrcUTF8,SmallVectorImpl<UTF16> & DstUTF16)200 bool convertUTF8ToUTF16String(StringRef SrcUTF8,
201 SmallVectorImpl<UTF16> &DstUTF16) {
202 assert(DstUTF16.empty());
203
204 // Avoid OOB by returning early on empty input.
205 if (SrcUTF8.empty()) {
206 DstUTF16.push_back(0);
207 DstUTF16.pop_back();
208 return true;
209 }
210
211 const UTF8 *Src = reinterpret_cast<const UTF8 *>(SrcUTF8.begin());
212 const UTF8 *SrcEnd = reinterpret_cast<const UTF8 *>(SrcUTF8.end());
213
214 // Allocate the same number of UTF-16 code units as UTF-8 code units. Encoding
215 // as UTF-16 should always require the same amount or less code units than the
216 // UTF-8 encoding. Allocate one extra byte for the null terminator though,
217 // so that someone calling DstUTF16.data() gets a null terminated string.
218 // We resize down later so we don't have to worry that this over allocates.
219 DstUTF16.resize(SrcUTF8.size()+1);
220 UTF16 *Dst = &DstUTF16[0];
221 UTF16 *DstEnd = Dst + DstUTF16.size();
222
223 ConversionResult CR =
224 ConvertUTF8toUTF16(&Src, SrcEnd, &Dst, DstEnd, strictConversion);
225 assert(CR != targetExhausted);
226
227 if (CR != conversionOK) {
228 DstUTF16.clear();
229 return false;
230 }
231
232 DstUTF16.resize(Dst - &DstUTF16[0]);
233 DstUTF16.push_back(0);
234 DstUTF16.pop_back();
235 return true;
236 }
237
238 static_assert(sizeof(wchar_t) == 1 || sizeof(wchar_t) == 2 ||
239 sizeof(wchar_t) == 4,
240 "Expected wchar_t to be 1, 2, or 4 bytes");
241
242 template <typename TResult>
ConvertUTF8toWideInternal(llvm::StringRef Source,TResult & Result)243 static inline bool ConvertUTF8toWideInternal(llvm::StringRef Source,
244 TResult &Result) {
245 // Even in the case of UTF-16, the number of bytes in a UTF-8 string is
246 // at least as large as the number of elements in the resulting wide
247 // string, because surrogate pairs take at least 4 bytes in UTF-8.
248 Result.resize(Source.size() + 1);
249 char *ResultPtr = reinterpret_cast<char *>(&Result[0]);
250 const UTF8 *ErrorPtr;
251 if (!ConvertUTF8toWide(sizeof(wchar_t), Source, ResultPtr, ErrorPtr)) {
252 Result.clear();
253 return false;
254 }
255 Result.resize(reinterpret_cast<wchar_t *>(ResultPtr) - &Result[0]);
256 return true;
257 }
258
ConvertUTF8toWide(llvm::StringRef Source,std::wstring & Result)259 bool ConvertUTF8toWide(llvm::StringRef Source, std::wstring &Result) {
260 return ConvertUTF8toWideInternal(Source, Result);
261 }
262
ConvertUTF8toWide(const char * Source,std::wstring & Result)263 bool ConvertUTF8toWide(const char *Source, std::wstring &Result) {
264 if (!Source) {
265 Result.clear();
266 return true;
267 }
268 return ConvertUTF8toWide(llvm::StringRef(Source), Result);
269 }
270
convertWideToUTF8(const std::wstring & Source,std::string & Result)271 bool convertWideToUTF8(const std::wstring &Source, std::string &Result) {
272 if (sizeof(wchar_t) == 1) {
273 const UTF8 *Start = reinterpret_cast<const UTF8 *>(Source.data());
274 const UTF8 *End =
275 reinterpret_cast<const UTF8 *>(Source.data() + Source.size());
276 if (!isLegalUTF8String(&Start, End))
277 return false;
278 Result.resize(Source.size());
279 memcpy(&Result[0], Source.data(), Source.size());
280 return true;
281 } else if (sizeof(wchar_t) == 2) {
282 return convertUTF16ToUTF8String(
283 llvm::ArrayRef<UTF16>(reinterpret_cast<const UTF16 *>(Source.data()),
284 Source.size()),
285 Result);
286 } else if (sizeof(wchar_t) == 4) {
287 const UTF32 *Start = reinterpret_cast<const UTF32 *>(Source.data());
288 const UTF32 *End =
289 reinterpret_cast<const UTF32 *>(Source.data() + Source.size());
290 Result.resize(UNI_MAX_UTF8_BYTES_PER_CODE_POINT * Source.size());
291 UTF8 *ResultPtr = reinterpret_cast<UTF8 *>(&Result[0]);
292 UTF8 *ResultEnd = reinterpret_cast<UTF8 *>(&Result[0] + Result.size());
293 if (ConvertUTF32toUTF8(&Start, End, &ResultPtr, ResultEnd,
294 strictConversion) == conversionOK) {
295 Result.resize(reinterpret_cast<char *>(ResultPtr) - &Result[0]);
296 return true;
297 } else {
298 Result.clear();
299 return false;
300 }
301 } else {
302 llvm_unreachable(
303 "Control should never reach this point; see static_assert further up");
304 }
305 }
306
307 } // end namespace llvm
308
309