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1 //===-- ConvertUTFWrapper.cpp - Wrap ConvertUTF.h with clang data types -----===
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 #include "llvm/Support/ConvertUTF.h"
11 #include "llvm/ADT/ArrayRef.h"
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/Support/ErrorHandling.h"
14 #include "llvm/Support/SwapByteOrder.h"
15 #include <string>
16 #include <vector>
17 
18 namespace llvm {
19 
ConvertUTF8toWide(unsigned WideCharWidth,llvm::StringRef Source,char * & ResultPtr,const UTF8 * & ErrorPtr)20 bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source,
21                        char *&ResultPtr, const UTF8 *&ErrorPtr) {
22   assert(WideCharWidth == 1 || WideCharWidth == 2 || WideCharWidth == 4);
23   ConversionResult result = conversionOK;
24   // Copy the character span over.
25   if (WideCharWidth == 1) {
26     const UTF8 *Pos = reinterpret_cast<const UTF8*>(Source.begin());
27     if (!isLegalUTF8String(&Pos, reinterpret_cast<const UTF8*>(Source.end()))) {
28       result = sourceIllegal;
29       ErrorPtr = Pos;
30     } else {
31       memcpy(ResultPtr, Source.data(), Source.size());
32       ResultPtr += Source.size();
33     }
34   } else if (WideCharWidth == 2) {
35     const UTF8 *sourceStart = (const UTF8*)Source.data();
36     // FIXME: Make the type of the result buffer correct instead of
37     // using reinterpret_cast.
38     UTF16 *targetStart = reinterpret_cast<UTF16*>(ResultPtr);
39     ConversionFlags flags = strictConversion;
40     result = ConvertUTF8toUTF16(
41         &sourceStart, sourceStart + Source.size(),
42         &targetStart, targetStart + Source.size(), flags);
43     if (result == conversionOK)
44       ResultPtr = reinterpret_cast<char*>(targetStart);
45     else
46       ErrorPtr = sourceStart;
47   } else if (WideCharWidth == 4) {
48     const UTF8 *sourceStart = (const UTF8*)Source.data();
49     // FIXME: Make the type of the result buffer correct instead of
50     // using reinterpret_cast.
51     UTF32 *targetStart = reinterpret_cast<UTF32*>(ResultPtr);
52     ConversionFlags flags = strictConversion;
53     result = ConvertUTF8toUTF32(
54         &sourceStart, sourceStart + Source.size(),
55         &targetStart, targetStart + Source.size(), flags);
56     if (result == conversionOK)
57       ResultPtr = reinterpret_cast<char*>(targetStart);
58     else
59       ErrorPtr = sourceStart;
60   }
61   assert((result != targetExhausted)
62          && "ConvertUTF8toUTFXX exhausted target buffer");
63   return result == conversionOK;
64 }
65 
ConvertCodePointToUTF8(unsigned Source,char * & ResultPtr)66 bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr) {
67   const UTF32 *SourceStart = &Source;
68   const UTF32 *SourceEnd = SourceStart + 1;
69   UTF8 *TargetStart = reinterpret_cast<UTF8 *>(ResultPtr);
70   UTF8 *TargetEnd = TargetStart + 4;
71   ConversionResult CR = ConvertUTF32toUTF8(&SourceStart, SourceEnd,
72                                            &TargetStart, TargetEnd,
73                                            strictConversion);
74   if (CR != conversionOK)
75     return false;
76 
77   ResultPtr = reinterpret_cast<char*>(TargetStart);
78   return true;
79 }
80 
hasUTF16ByteOrderMark(ArrayRef<char> S)81 bool hasUTF16ByteOrderMark(ArrayRef<char> S) {
82   return (S.size() >= 2 &&
83           ((S[0] == '\xff' && S[1] == '\xfe') ||
84            (S[0] == '\xfe' && S[1] == '\xff')));
85 }
86 
convertUTF16ToUTF8String(ArrayRef<char> SrcBytes,std::string & Out)87 bool convertUTF16ToUTF8String(ArrayRef<char> SrcBytes, std::string &Out) {
88   assert(Out.empty());
89 
90   // Error out on an uneven byte count.
91   if (SrcBytes.size() % 2)
92     return false;
93 
94   // Avoid OOB by returning early on empty input.
95   if (SrcBytes.empty())
96     return true;
97 
98   const UTF16 *Src = reinterpret_cast<const UTF16 *>(SrcBytes.begin());
99   const UTF16 *SrcEnd = reinterpret_cast<const UTF16 *>(SrcBytes.end());
100 
101   // Byteswap if necessary.
102   std::vector<UTF16> ByteSwapped;
103   if (Src[0] == UNI_UTF16_BYTE_ORDER_MARK_SWAPPED) {
104     ByteSwapped.insert(ByteSwapped.end(), Src, SrcEnd);
105     for (unsigned I = 0, E = ByteSwapped.size(); I != E; ++I)
106       ByteSwapped[I] = llvm::sys::SwapByteOrder_16(ByteSwapped[I]);
107     Src = &ByteSwapped[0];
108     SrcEnd = &ByteSwapped[ByteSwapped.size() - 1] + 1;
109   }
110 
111   // Skip the BOM for conversion.
112   if (Src[0] == UNI_UTF16_BYTE_ORDER_MARK_NATIVE)
113     Src++;
114 
115   // Just allocate enough space up front.  We'll shrink it later.  Allocate
116   // enough that we can fit a null terminator without reallocating.
117   Out.resize(SrcBytes.size() * UNI_MAX_UTF8_BYTES_PER_CODE_POINT + 1);
118   UTF8 *Dst = reinterpret_cast<UTF8 *>(&Out[0]);
119   UTF8 *DstEnd = Dst + Out.size();
120 
121   ConversionResult CR =
122       ConvertUTF16toUTF8(&Src, SrcEnd, &Dst, DstEnd, strictConversion);
123   assert(CR != targetExhausted);
124 
125   if (CR != conversionOK) {
126     Out.clear();
127     return false;
128   }
129 
130   Out.resize(reinterpret_cast<char *>(Dst) - &Out[0]);
131   Out.push_back(0);
132   Out.pop_back();
133   return true;
134 }
135 
convertUTF16ToUTF8String(ArrayRef<UTF16> Src,std::string & Out)136 bool convertUTF16ToUTF8String(ArrayRef<UTF16> Src, std::string &Out)
137 {
138   return convertUTF16ToUTF8String(
139       llvm::ArrayRef<char>(reinterpret_cast<const char *>(Src.data()),
140       Src.size() * sizeof(UTF16)), Out);
141 }
142 
convertUTF8ToUTF16String(StringRef SrcUTF8,SmallVectorImpl<UTF16> & DstUTF16)143 bool convertUTF8ToUTF16String(StringRef SrcUTF8,
144                               SmallVectorImpl<UTF16> &DstUTF16) {
145   assert(DstUTF16.empty());
146 
147   // Avoid OOB by returning early on empty input.
148   if (SrcUTF8.empty()) {
149     DstUTF16.push_back(0);
150     DstUTF16.pop_back();
151     return true;
152   }
153 
154   const UTF8 *Src = reinterpret_cast<const UTF8 *>(SrcUTF8.begin());
155   const UTF8 *SrcEnd = reinterpret_cast<const UTF8 *>(SrcUTF8.end());
156 
157   // Allocate the same number of UTF-16 code units as UTF-8 code units. Encoding
158   // as UTF-16 should always require the same amount or less code units than the
159   // UTF-8 encoding.  Allocate one extra byte for the null terminator though,
160   // so that someone calling DstUTF16.data() gets a null terminated string.
161   // We resize down later so we don't have to worry that this over allocates.
162   DstUTF16.resize(SrcUTF8.size()+1);
163   UTF16 *Dst = &DstUTF16[0];
164   UTF16 *DstEnd = Dst + DstUTF16.size();
165 
166   ConversionResult CR =
167       ConvertUTF8toUTF16(&Src, SrcEnd, &Dst, DstEnd, strictConversion);
168   assert(CR != targetExhausted);
169 
170   if (CR != conversionOK) {
171     DstUTF16.clear();
172     return false;
173   }
174 
175   DstUTF16.resize(Dst - &DstUTF16[0]);
176   DstUTF16.push_back(0);
177   DstUTF16.pop_back();
178   return true;
179 }
180 
181 static_assert(sizeof(wchar_t) == 1 || sizeof(wchar_t) == 2 ||
182                   sizeof(wchar_t) == 4,
183               "Expected wchar_t to be 1, 2, or 4 bytes");
184 
185 template <typename TResult>
ConvertUTF8toWideInternal(llvm::StringRef Source,TResult & Result)186 static inline bool ConvertUTF8toWideInternal(llvm::StringRef Source,
187                                              TResult &Result) {
188   // Even in the case of UTF-16, the number of bytes in a UTF-8 string is
189   // at least as large as the number of elements in the resulting wide
190   // string, because surrogate pairs take at least 4 bytes in UTF-8.
191   Result.resize(Source.size() + 1);
192   char *ResultPtr = reinterpret_cast<char *>(&Result[0]);
193   const UTF8 *ErrorPtr;
194   if (!ConvertUTF8toWide(sizeof(wchar_t), Source, ResultPtr, ErrorPtr)) {
195     Result.clear();
196     return false;
197   }
198   Result.resize(reinterpret_cast<wchar_t *>(ResultPtr) - &Result[0]);
199   return true;
200 }
201 
ConvertUTF8toWide(llvm::StringRef Source,std::wstring & Result)202 bool ConvertUTF8toWide(llvm::StringRef Source, std::wstring &Result) {
203   return ConvertUTF8toWideInternal(Source, Result);
204 }
205 
ConvertUTF8toWide(const char * Source,std::wstring & Result)206 bool ConvertUTF8toWide(const char *Source, std::wstring &Result) {
207   if (!Source) {
208     Result.clear();
209     return true;
210   }
211   return ConvertUTF8toWide(llvm::StringRef(Source), Result);
212 }
213 
convertWideToUTF8(const std::wstring & Source,std::string & Result)214 bool convertWideToUTF8(const std::wstring &Source, std::string &Result) {
215   if (sizeof(wchar_t) == 1) {
216     const UTF8 *Start = reinterpret_cast<const UTF8 *>(Source.data());
217     const UTF8 *End =
218         reinterpret_cast<const UTF8 *>(Source.data() + Source.size());
219     if (!isLegalUTF8String(&Start, End))
220       return false;
221     Result.resize(Source.size());
222     memcpy(&Result[0], Source.data(), Source.size());
223     return true;
224   } else if (sizeof(wchar_t) == 2) {
225     return convertUTF16ToUTF8String(
226         llvm::ArrayRef<UTF16>(reinterpret_cast<const UTF16 *>(Source.data()),
227                               Source.size()),
228         Result);
229   } else if (sizeof(wchar_t) == 4) {
230     const UTF32 *Start = reinterpret_cast<const UTF32 *>(Source.data());
231     const UTF32 *End =
232         reinterpret_cast<const UTF32 *>(Source.data() + Source.size());
233     Result.resize(UNI_MAX_UTF8_BYTES_PER_CODE_POINT * Source.size());
234     UTF8 *ResultPtr = reinterpret_cast<UTF8 *>(&Result[0]);
235     UTF8 *ResultEnd = reinterpret_cast<UTF8 *>(&Result[0] + Result.size());
236     if (ConvertUTF32toUTF8(&Start, End, &ResultPtr, ResultEnd,
237                            strictConversion) == conversionOK) {
238       Result.resize(reinterpret_cast<char *>(ResultPtr) - &Result[0]);
239       return true;
240     } else {
241       Result.clear();
242       return false;
243     }
244   } else {
245     llvm_unreachable(
246         "Control should never reach this point; see static_assert further up");
247   }
248 }
249 
250 } // end namespace llvm
251 
252