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
18namespace llvm {
19
20bool 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
66bool 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
81bool 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
87bool 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
136bool 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
143bool 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
181static_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
185template <typename TResult>
186static 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
202bool ConvertUTF8toWide(llvm::StringRef Source, std::wstring &Result) {
203  return ConvertUTF8toWideInternal(Source, Result);
204}
205
206bool 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
214bool 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