1/* 2 * Copyright (C) 2012 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#ifndef CodeBlockHash_h 27#define CodeBlockHash_h 28 29#include "CodeSpecializationKind.h" 30#include <wtf/PrintStream.h> 31 32// CodeBlock hashes are useful for informally identifying code blocks. They correspond 33// to the low 32 bits of a SHA1 hash of the source code with two low bit flipped 34// according to the role that the code block serves (call, construct). Additionally, the 35// hashes are typically operated over using a string in which the hash is transformed 36// into a 6-byte alphanumeric representation. This can be retrieved by using 37// toString(const CodeBlockHash&). Finally, we support CodeBlockHashes for native 38// functions, in which case the hash is replaced by the function address. 39 40namespace JSC { 41 42class SourceCode; 43 44class CodeBlockHash { 45public: 46 CodeBlockHash() 47 : m_hash(0) 48 { 49 } 50 51 explicit CodeBlockHash(unsigned hash) 52 : m_hash(hash) 53 { 54 } 55 56 CodeBlockHash(const SourceCode&, CodeSpecializationKind); 57 58 explicit CodeBlockHash(const char*); 59 60 bool isSet() const { return !!m_hash; } 61 bool operator!() const { return !isSet(); } 62 63 unsigned hash() const { return m_hash; } 64 65 void dump(PrintStream&) const; 66 67 // Comparison methods useful for bisection. 68 bool operator==(const CodeBlockHash& other) const { return hash() == other.hash(); } 69 bool operator!=(const CodeBlockHash& other) const { return hash() != other.hash(); } 70 bool operator<(const CodeBlockHash& other) const { return hash() < other.hash(); } 71 bool operator>(const CodeBlockHash& other) const { return hash() > other.hash(); } 72 bool operator<=(const CodeBlockHash& other) const { return hash() <= other.hash(); } 73 bool operator>=(const CodeBlockHash& other) const { return hash() >= other.hash(); } 74 75private: 76 unsigned m_hash; 77}; 78 79} // namespace JSC 80 81#endif // CodeBlockHash_h 82