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1 /*
2  * Copyright (C) 2004, 2006, 2007, 2008 Apple Inc. All rights reserved.
3  * Copyright (C) 2006 Alexey Proskuryakov <ap@nypop.com>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "config.h"
28 #include "TextCodecICU.h"
29 
30 #include "CharacterNames.h"
31 #include "CString.h"
32 #include "PlatformString.h"
33 #include "ThreadGlobalData.h"
34 #include <unicode/ucnv.h>
35 #include <unicode/ucnv_cb.h>
36 #include <wtf/Assertions.h>
37 #include <wtf/PassOwnPtr.h>
38 #include <wtf/StringExtras.h>
39 #include <wtf/Threading.h>
40 
41 using std::min;
42 
43 namespace WebCore {
44 
45 const size_t ConversionBufferSize = 16384;
46 
~ICUConverterWrapper()47 ICUConverterWrapper::~ICUConverterWrapper()
48 {
49     if (converter)
50         ucnv_close(converter);
51 }
52 
cachedConverterICU()53 static UConverter*& cachedConverterICU()
54 {
55     return threadGlobalData().cachedConverterICU().converter;
56 }
57 
newTextCodecICU(const TextEncoding & encoding,const void *)58 static PassOwnPtr<TextCodec> newTextCodecICU(const TextEncoding& encoding, const void*)
59 {
60     return new TextCodecICU(encoding);
61 }
62 
registerBaseEncodingNames(EncodingNameRegistrar registrar)63 void TextCodecICU::registerBaseEncodingNames(EncodingNameRegistrar registrar)
64 {
65     registrar("UTF-8", "UTF-8");
66 }
67 
registerBaseCodecs(TextCodecRegistrar registrar)68 void TextCodecICU::registerBaseCodecs(TextCodecRegistrar registrar)
69 {
70     registrar("UTF-8", newTextCodecICU, 0);
71 }
72 
73 // FIXME: Registering all the encodings we get from ucnv_getAvailableName
74 // includes encodings we don't want or need. For example, all
75 // the encodings with commas and version numbers.
76 
registerExtendedEncodingNames(EncodingNameRegistrar registrar)77 void TextCodecICU::registerExtendedEncodingNames(EncodingNameRegistrar registrar)
78 {
79     // We register Hebrew with logical ordering using a separate name.
80     // Otherwise, this would share the same canonical name as the
81     // visual ordering case, and then TextEncoding could not tell them
82     // apart; ICU treats these names as synonyms.
83     registrar("ISO-8859-8-I", "ISO-8859-8-I");
84 
85     int32_t numEncodings = ucnv_countAvailable();
86     for (int32_t i = 0; i < numEncodings; ++i) {
87         const char* name = ucnv_getAvailableName(i);
88         UErrorCode error = U_ZERO_ERROR;
89         // Try MIME before trying IANA to pick up commonly used names like
90         // 'EUC-JP' instead of horrendously long names like
91         // 'Extended_UNIX_Code_Packed_Format_for_Japanese'.
92         const char* standardName = ucnv_getStandardName(name, "MIME", &error);
93         if (!U_SUCCESS(error) || !standardName) {
94             error = U_ZERO_ERROR;
95             // Try IANA to pick up 'windows-12xx' and other names
96             // which are not preferred MIME names but are widely used.
97             standardName = ucnv_getStandardName(name, "IANA", &error);
98             if (!U_SUCCESS(error) || !standardName)
99                 continue;
100         }
101 
102         // 1. Treat GB2312 encoding as GBK (its more modern superset), to match other browsers.
103         // 2. On the Web, GB2312 is encoded as EUC-CN or HZ, while ICU provides a native encoding
104         //    for encoding GB_2312-80 and several others. So, we need to override this behavior, too.
105         if (strcmp(standardName, "GB2312") == 0 || strcmp(standardName, "GB_2312-80") == 0)
106             standardName = "GBK";
107         // Similarly, EUC-KR encodings all map to an extended version.
108         else if (strcmp(standardName, "KSC_5601") == 0 || strcmp(standardName, "EUC-KR") == 0 || strcmp(standardName, "cp1363") == 0)
109             standardName = "windows-949";
110         // And so on.
111         else if (strcasecmp(standardName, "iso-8859-9") == 0) // This name is returned in different case by ICU 3.2 and 3.6.
112             standardName = "windows-1254";
113         else if (strcmp(standardName, "TIS-620") == 0)
114             standardName = "windows-874";
115 
116         registrar(standardName, standardName);
117 
118         uint16_t numAliases = ucnv_countAliases(name, &error);
119         ASSERT(U_SUCCESS(error));
120         if (U_SUCCESS(error))
121             for (uint16_t j = 0; j < numAliases; ++j) {
122                 error = U_ZERO_ERROR;
123                 const char* alias = ucnv_getAlias(name, j, &error);
124                 ASSERT(U_SUCCESS(error));
125                 if (U_SUCCESS(error) && alias != standardName)
126                     registrar(alias, standardName);
127             }
128     }
129 
130     // Additional aliases.
131     // These are present in modern versions of ICU, but not in ICU 3.2 (shipped with Mac OS X 10.4).
132     registrar("macroman", "macintosh");
133     registrar("maccyrillic", "x-mac-cyrillic");
134 
135     // Additional aliases that historically were present in the encoding
136     // table in WebKit on Macintosh that don't seem to be present in ICU.
137     // Perhaps we can prove these are not used on the web and remove them.
138     // Or perhaps we can get them added to ICU.
139     registrar("xmacroman", "macintosh");
140     registrar("xmacukrainian", "x-mac-cyrillic");
141     registrar("cnbig5", "Big5");
142     registrar("xxbig5", "Big5");
143     registrar("cngb", "GBK");
144     registrar("csgb231280", "GBK");
145     registrar("xeuccn", "GBK");
146     registrar("xgbk", "GBK");
147     registrar("csISO88598I", "ISO_8859-8-I");
148     registrar("koi", "KOI8-R");
149     registrar("logical", "ISO-8859-8-I");
150     registrar("unicode11utf8", "UTF-8");
151     registrar("unicode20utf8", "UTF-8");
152     registrar("xunicode20utf8", "UTF-8");
153     registrar("visual", "ISO-8859-8");
154     registrar("winarabic", "windows-1256");
155     registrar("winbaltic", "windows-1257");
156     registrar("wincyrillic", "windows-1251");
157     registrar("iso885911", "windows-874");
158     registrar("dos874", "windows-874");
159     registrar("wingreek", "windows-1253");
160     registrar("winhebrew", "windows-1255");
161     registrar("winlatin2", "windows-1250");
162     registrar("winturkish", "windows-1254");
163     registrar("winvietnamese", "windows-1258");
164     registrar("xcp1250", "windows-1250");
165     registrar("xcp1251", "windows-1251");
166     registrar("xeuc", "EUC-JP");
167     registrar("xwindows949", "windows-949");
168     registrar("xuhc", "windows-949");
169 
170     // These aliases are present in modern versions of ICU, but use different codecs, and have no standard names.
171     // They are not present in ICU 3.2.
172     registrar("dos720", "cp864");
173     registrar("jis7", "ISO-2022-JP");
174 }
175 
registerExtendedCodecs(TextCodecRegistrar registrar)176 void TextCodecICU::registerExtendedCodecs(TextCodecRegistrar registrar)
177 {
178     // See comment above in registerEncodingNames.
179     registrar("ISO-8859-8-I", newTextCodecICU, 0);
180 
181     int32_t numEncodings = ucnv_countAvailable();
182     for (int32_t i = 0; i < numEncodings; ++i) {
183         const char* name = ucnv_getAvailableName(i);
184         UErrorCode error = U_ZERO_ERROR;
185         const char* standardName = ucnv_getStandardName(name, "MIME", &error);
186         if (!U_SUCCESS(error) || !standardName) {
187             error = U_ZERO_ERROR;
188             standardName = ucnv_getStandardName(name, "IANA", &error);
189             if (!U_SUCCESS(error) || !standardName)
190                 continue;
191         }
192         registrar(standardName, newTextCodecICU, 0);
193     }
194 }
195 
TextCodecICU(const TextEncoding & encoding)196 TextCodecICU::TextCodecICU(const TextEncoding& encoding)
197     : m_encoding(encoding)
198     , m_numBufferedBytes(0)
199     , m_converterICU(0)
200     , m_needsGBKFallbacks(false)
201 {
202 }
203 
~TextCodecICU()204 TextCodecICU::~TextCodecICU()
205 {
206     releaseICUConverter();
207 }
208 
releaseICUConverter() const209 void TextCodecICU::releaseICUConverter() const
210 {
211     if (m_converterICU) {
212         UConverter*& cachedConverter = cachedConverterICU();
213         if (cachedConverter)
214             ucnv_close(cachedConverter);
215         cachedConverter = m_converterICU;
216         m_converterICU = 0;
217     }
218 }
219 
createICUConverter() const220 void TextCodecICU::createICUConverter() const
221 {
222     ASSERT(!m_converterICU);
223 
224     const char* name = m_encoding.name();
225     m_needsGBKFallbacks = name[0] == 'G' && name[1] == 'B' && name[2] == 'K' && !name[3];
226 
227     UErrorCode err;
228 
229     UConverter*& cachedConverter = cachedConverterICU();
230     if (cachedConverter) {
231         err = U_ZERO_ERROR;
232         const char* cachedName = ucnv_getName(cachedConverter, &err);
233         if (U_SUCCESS(err) && m_encoding == cachedName) {
234             m_converterICU = cachedConverter;
235             cachedConverter = 0;
236             return;
237         }
238     }
239 
240     err = U_ZERO_ERROR;
241     m_converterICU = ucnv_open(m_encoding.name(), &err);
242 #if !LOG_DISABLED
243     if (err == U_AMBIGUOUS_ALIAS_WARNING)
244         LOG_ERROR("ICU ambiguous alias warning for encoding: %s", m_encoding.name());
245 #endif
246     if (m_converterICU)
247         ucnv_setFallback(m_converterICU, TRUE);
248 }
249 
decodeToBuffer(UChar * target,UChar * targetLimit,const char * & source,const char * sourceLimit,int32_t * offsets,bool flush,UErrorCode & err)250 int TextCodecICU::decodeToBuffer(UChar* target, UChar* targetLimit, const char*& source, const char* sourceLimit, int32_t* offsets, bool flush, UErrorCode& err)
251 {
252     UChar* targetStart = target;
253     err = U_ZERO_ERROR;
254     ucnv_toUnicode(m_converterICU, &target, targetLimit, &source, sourceLimit, offsets, flush, &err);
255     return target - targetStart;
256 }
257 
258 class ErrorCallbackSetter {
259 public:
ErrorCallbackSetter(UConverter * converter,bool stopOnError)260     ErrorCallbackSetter(UConverter* converter, bool stopOnError)
261         : m_converter(converter)
262         , m_shouldStopOnEncodingErrors(stopOnError)
263     {
264         if (m_shouldStopOnEncodingErrors) {
265             UErrorCode err = U_ZERO_ERROR;
266             ucnv_setToUCallBack(m_converter, UCNV_TO_U_CALLBACK_SUBSTITUTE,
267                            UCNV_SUB_STOP_ON_ILLEGAL, &m_savedAction,
268                            &m_savedContext, &err);
269             ASSERT(err == U_ZERO_ERROR);
270         }
271     }
~ErrorCallbackSetter()272     ~ErrorCallbackSetter()
273     {
274         if (m_shouldStopOnEncodingErrors) {
275             UErrorCode err = U_ZERO_ERROR;
276             const void* oldContext;
277             UConverterToUCallback oldAction;
278             ucnv_setToUCallBack(m_converter, m_savedAction,
279                    m_savedContext, &oldAction,
280                    &oldContext, &err);
281             ASSERT(oldAction == UCNV_TO_U_CALLBACK_SUBSTITUTE);
282             ASSERT(!strcmp(static_cast<const char*>(oldContext), UCNV_SUB_STOP_ON_ILLEGAL));
283             ASSERT(err == U_ZERO_ERROR);
284         }
285     }
286 private:
287     UConverter* m_converter;
288     bool m_shouldStopOnEncodingErrors;
289     const void* m_savedContext;
290     UConverterToUCallback m_savedAction;
291 };
292 
decode(const char * bytes,size_t length,bool flush,bool stopOnError,bool & sawError)293 String TextCodecICU::decode(const char* bytes, size_t length, bool flush, bool stopOnError, bool& sawError)
294 {
295     // Get a converter for the passed-in encoding.
296     if (!m_converterICU) {
297         createICUConverter();
298         ASSERT(m_converterICU);
299         if (!m_converterICU) {
300             LOG_ERROR("error creating ICU encoder even though encoding was in table");
301             return String();
302         }
303     }
304 
305     ErrorCallbackSetter callbackSetter(m_converterICU, stopOnError);
306 
307     Vector<UChar> result;
308 
309     UChar buffer[ConversionBufferSize];
310     UChar* bufferLimit = buffer + ConversionBufferSize;
311     const char* source = reinterpret_cast<const char*>(bytes);
312     const char* sourceLimit = source + length;
313     int32_t* offsets = NULL;
314     UErrorCode err = U_ZERO_ERROR;
315 
316     do {
317         int ucharsDecoded = decodeToBuffer(buffer, bufferLimit, source, sourceLimit, offsets, flush, err);
318         result.append(buffer, ucharsDecoded);
319     } while (err == U_BUFFER_OVERFLOW_ERROR);
320 
321     if (U_FAILURE(err)) {
322         // flush the converter so it can be reused, and not be bothered by this error.
323         do {
324             decodeToBuffer(buffer, bufferLimit, source, sourceLimit, offsets, true, err);
325         } while (source < sourceLimit);
326         sawError = true;
327     }
328 
329     String resultString = String::adopt(result);
330 
331     // <http://bugs.webkit.org/show_bug.cgi?id=17014>
332     // Simplified Chinese pages use the code A3A0 to mean "full-width space", but ICU decodes it as U+E5E5.
333     if (strcmp(m_encoding.name(), "GBK") == 0 || strcasecmp(m_encoding.name(), "gb18030") == 0)
334         resultString.replace(0xE5E5, ideographicSpace);
335 
336     return resultString;
337 }
338 
339 // We need to apply these fallbacks ourselves as they are not currently supported by ICU and
340 // they were provided by the old TEC encoding path
341 // Needed to fix <rdar://problem/4708689>
getGbkEscape(UChar32 codePoint)342 static UChar getGbkEscape(UChar32 codePoint)
343 {
344     switch (codePoint) {
345         case 0x01F9:
346             return 0xE7C8;
347         case 0x1E3F:
348             return 0xE7C7;
349         case 0x22EF:
350             return 0x2026;
351         case 0x301C:
352             return 0xFF5E;
353         default:
354             return 0;
355     }
356 }
357 
358 // Invalid character handler when writing escaped entities for unrepresentable
359 // characters. See the declaration of TextCodec::encode for more.
urlEscapedEntityCallback(const void * context,UConverterFromUnicodeArgs * fromUArgs,const UChar * codeUnits,int32_t length,UChar32 codePoint,UConverterCallbackReason reason,UErrorCode * err)360 static void urlEscapedEntityCallback(const void* context, UConverterFromUnicodeArgs* fromUArgs, const UChar* codeUnits, int32_t length,
361                                      UChar32 codePoint, UConverterCallbackReason reason, UErrorCode* err)
362 {
363     if (reason == UCNV_UNASSIGNED) {
364         *err = U_ZERO_ERROR;
365 
366         UnencodableReplacementArray entity;
367         int entityLen = TextCodec::getUnencodableReplacement(codePoint, URLEncodedEntitiesForUnencodables, entity);
368         ucnv_cbFromUWriteBytes(fromUArgs, entity, entityLen, 0, err);
369     } else
370         UCNV_FROM_U_CALLBACK_ESCAPE(context, fromUArgs, codeUnits, length, codePoint, reason, err);
371 }
372 
373 // Substitutes special GBK characters, escaping all other unassigned entities.
gbkCallbackEscape(const void * context,UConverterFromUnicodeArgs * fromUArgs,const UChar * codeUnits,int32_t length,UChar32 codePoint,UConverterCallbackReason reason,UErrorCode * err)374 static void gbkCallbackEscape(const void* context, UConverterFromUnicodeArgs* fromUArgs, const UChar* codeUnits, int32_t length,
375                               UChar32 codePoint, UConverterCallbackReason reason, UErrorCode* err)
376 {
377     UChar outChar;
378     if (reason == UCNV_UNASSIGNED && (outChar = getGbkEscape(codePoint))) {
379         const UChar* source = &outChar;
380         *err = U_ZERO_ERROR;
381         ucnv_cbFromUWriteUChars(fromUArgs, &source, source + 1, 0, err);
382         return;
383     }
384     UCNV_FROM_U_CALLBACK_ESCAPE(context, fromUArgs, codeUnits, length, codePoint, reason, err);
385 }
386 
387 // Combines both gbkUrlEscapedEntityCallback and GBK character substitution.
gbkUrlEscapedEntityCallack(const void * context,UConverterFromUnicodeArgs * fromUArgs,const UChar * codeUnits,int32_t length,UChar32 codePoint,UConverterCallbackReason reason,UErrorCode * err)388 static void gbkUrlEscapedEntityCallack(const void* context, UConverterFromUnicodeArgs* fromUArgs, const UChar* codeUnits, int32_t length,
389                                        UChar32 codePoint, UConverterCallbackReason reason, UErrorCode* err)
390 {
391     if (reason == UCNV_UNASSIGNED) {
392         if (UChar outChar = getGbkEscape(codePoint)) {
393             const UChar* source = &outChar;
394             *err = U_ZERO_ERROR;
395             ucnv_cbFromUWriteUChars(fromUArgs, &source, source + 1, 0, err);
396             return;
397         }
398         urlEscapedEntityCallback(context, fromUArgs, codeUnits, length, codePoint, reason, err);
399         return;
400     }
401     UCNV_FROM_U_CALLBACK_ESCAPE(context, fromUArgs, codeUnits, length, codePoint, reason, err);
402 }
403 
gbkCallbackSubstitute(const void * context,UConverterFromUnicodeArgs * fromUArgs,const UChar * codeUnits,int32_t length,UChar32 codePoint,UConverterCallbackReason reason,UErrorCode * err)404 static void gbkCallbackSubstitute(const void* context, UConverterFromUnicodeArgs* fromUArgs, const UChar* codeUnits, int32_t length,
405                                   UChar32 codePoint, UConverterCallbackReason reason, UErrorCode* err)
406 {
407     UChar outChar;
408     if (reason == UCNV_UNASSIGNED && (outChar = getGbkEscape(codePoint))) {
409         const UChar* source = &outChar;
410         *err = U_ZERO_ERROR;
411         ucnv_cbFromUWriteUChars(fromUArgs, &source, source + 1, 0, err);
412         return;
413     }
414     UCNV_FROM_U_CALLBACK_SUBSTITUTE(context, fromUArgs, codeUnits, length, codePoint, reason, err);
415 }
416 
encode(const UChar * characters,size_t length,UnencodableHandling handling)417 CString TextCodecICU::encode(const UChar* characters, size_t length, UnencodableHandling handling)
418 {
419     if (!length)
420         return "";
421 
422     if (!m_converterICU)
423         createICUConverter();
424     if (!m_converterICU)
425         return CString();
426 
427     // FIXME: We should see if there is "force ASCII range" mode in ICU;
428     // until then, we change the backslash into a yen sign.
429     // Encoding will change the yen sign back into a backslash.
430     String copy(characters, length);
431     copy = m_encoding.displayString(copy.impl());
432 
433     const UChar* source = copy.characters();
434     const UChar* sourceLimit = source + copy.length();
435 
436     UErrorCode err = U_ZERO_ERROR;
437 
438     switch (handling) {
439         case QuestionMarksForUnencodables:
440             ucnv_setSubstChars(m_converterICU, "?", 1, &err);
441             ucnv_setFromUCallBack(m_converterICU, m_needsGBKFallbacks ? gbkCallbackSubstitute : UCNV_FROM_U_CALLBACK_SUBSTITUTE, 0, 0, 0, &err);
442             break;
443         case EntitiesForUnencodables:
444             ucnv_setFromUCallBack(m_converterICU, m_needsGBKFallbacks ? gbkCallbackEscape : UCNV_FROM_U_CALLBACK_ESCAPE, UCNV_ESCAPE_XML_DEC, 0, 0, &err);
445             break;
446         case URLEncodedEntitiesForUnencodables:
447             ucnv_setFromUCallBack(m_converterICU, m_needsGBKFallbacks ? gbkUrlEscapedEntityCallack : urlEscapedEntityCallback, 0, 0, 0, &err);
448             break;
449     }
450 
451     ASSERT(U_SUCCESS(err));
452     if (U_FAILURE(err))
453         return CString();
454 
455     Vector<char> result;
456     size_t size = 0;
457     do {
458         char buffer[ConversionBufferSize];
459         char* target = buffer;
460         char* targetLimit = target + ConversionBufferSize;
461         err = U_ZERO_ERROR;
462         ucnv_fromUnicode(m_converterICU, &target, targetLimit, &source, sourceLimit, 0, true, &err);
463         size_t count = target - buffer;
464         result.grow(size + count);
465         memcpy(result.data() + size, buffer, count);
466         size += count;
467     } while (err == U_BUFFER_OVERFLOW_ERROR);
468 
469     return CString(result.data(), size);
470 }
471 
472 
473 } // namespace WebCore
474