1 /* 2 * Copyright (C) 2010 Apple Inc. All Rights Reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include "config.h" 27 28 #ifdef SKIP_STATIC_CONSTRUCTORS_ON_GCC 29 #define ATOMICSTRING_HIDE_GLOBALS 1 30 #endif 31 32 #include "AtomicString.h" 33 #include "DynamicAnnotations.h" 34 #include "StaticConstructors.h" 35 #include "StringImpl.h" 36 37 namespace WTF { 38 39 StringImpl* StringImpl::empty() 40 { 41 // FIXME: This works around a bug in our port of PCRE, that a regular expression 42 // run on the empty string may still perform a read from the first element, and 43 // as such we need this to be a valid pointer. No code should ever be reading 44 // from a zero length string, so this should be able to be a non-null pointer 45 // into the zero-page. 46 // Replace this with 'reinterpret_cast<UChar*>(static_cast<intptr_t>(1))' once 47 // PCRE goes away. 48 static UChar emptyUCharData = 0; 49 DEFINE_STATIC_LOCAL(StringImpl, emptyString, (&emptyUCharData, 0, ConstructStaticString)); 50 WTF_ANNOTATE_BENIGN_RACE(&emptyString, "Benign race on StringImpl::emptyString reference counter"); 51 return &emptyString; 52 } 53 54 JS_EXPORTDATA DEFINE_GLOBAL(AtomicString, nullAtom) 55 JS_EXPORTDATA DEFINE_GLOBAL(AtomicString, emptyAtom, "") 56 JS_EXPORTDATA DEFINE_GLOBAL(AtomicString, textAtom, "#text") 57 JS_EXPORTDATA DEFINE_GLOBAL(AtomicString, commentAtom, "#comment") 58 JS_EXPORTDATA DEFINE_GLOBAL(AtomicString, starAtom, "*") 59 JS_EXPORTDATA DEFINE_GLOBAL(AtomicString, xmlAtom, "xml") 60 JS_EXPORTDATA DEFINE_GLOBAL(AtomicString, xmlnsAtom, "xmlns") 61 62 void AtomicString::init() 63 { 64 static bool initialized; 65 if (!initialized) { 66 // Initialization is not thread safe, so this function must be called from the main thread first. 67 ASSERT(isMainThread()); 68 69 // Use placement new to initialize the globals. 70 new ((void*)&nullAtom) AtomicString; 71 new ((void*)&emptyAtom) AtomicString(""); 72 new ((void*)&textAtom) AtomicString("#text"); 73 new ((void*)&commentAtom) AtomicString("#comment"); 74 new ((void*)&starAtom) AtomicString("*"); 75 new ((void*)&xmlAtom) AtomicString("xml"); 76 new ((void*)&xmlnsAtom) AtomicString("xmlns"); 77 78 initialized = true; 79 } 80 } 81 82 } 83
