1 /* 2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/classFileStream.hpp" 27 #include "classfile/classLoader.hpp" 28 #include "classfile/dictionary.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "memory/resourceArea.hpp" 31 32 const bool ClassFileStream::verify = true; 33 const bool ClassFileStream::no_verification = false; 34 35 void ClassFileStream::truncated_file_error(TRAPS) const { 36 THROW_MSG(vmSymbols::java_lang_ClassFormatError(), "Truncated class file"); 37 } 38 39 ClassFileStream::ClassFileStream(const u1* buffer, 40 int length, 41 const char* source, 42 bool verify_stream) : 43 _buffer_start(buffer), 44 _buffer_end(buffer + length), 45 _current(buffer), 46 _source(source), 47 _need_verify(verify_stream) {} 48 49 const u1* ClassFileStream::clone_buffer() const { 50 u1* const new_buffer_start = NEW_RESOURCE_ARRAY(u1, length()); 51 memcpy(new_buffer_start, _buffer_start, length()); 52 return new_buffer_start; 53 } 54 55 const char* const ClassFileStream::clone_source() const { 56 const char* const src = source(); 57 char* source_copy = NULL; 58 if (src != NULL) { 59 size_t source_len = strlen(src); 60 source_copy = NEW_RESOURCE_ARRAY(char, source_len + 1); 61 strncpy(source_copy, src, source_len + 1); 62 } 63 return source_copy; 64 } 65 66 // Caller responsible for ResourceMark 67 // clone stream with a rewound position 68 const ClassFileStream* ClassFileStream::clone() const { 69 const u1* const new_buffer_start = clone_buffer(); 70 return new ClassFileStream(new_buffer_start, 71 length(), 72 clone_source(), 73 need_verify()); 74 } 75 76 u1 ClassFileStream::get_u1(TRAPS) const { 77 if (_need_verify) { 78 guarantee_more(1, CHECK_0); 79 } else { 80 assert(1 <= _buffer_end - _current, "buffer overflow"); 81 } 82 return *_current++; 83 } 84 85 u2 ClassFileStream::get_u2(TRAPS) const { 86 if (_need_verify) { 87 guarantee_more(2, CHECK_0); 88 } else { 89 assert(2 <= _buffer_end - _current, "buffer overflow"); 90 } 91 const u1* tmp = _current; 92 _current += 2; 93 return Bytes::get_Java_u2((address)tmp); 94 } 95 96 u4 ClassFileStream::get_u4(TRAPS) const { 97 if (_need_verify) { 98 guarantee_more(4, CHECK_0); 99 } else { 100 assert(4 <= _buffer_end - _current, "buffer overflow"); 101 } 102 const u1* tmp = _current; 103 _current += 4; 104 return Bytes::get_Java_u4((address)tmp); 105 } 106 107 u8 ClassFileStream::get_u8(TRAPS) const { 108 if (_need_verify) { 109 guarantee_more(8, CHECK_0); 110 } else { 111 assert(8 <= _buffer_end - _current, "buffer overflow"); 112 } 113 const u1* tmp = _current; 114 _current += 8; 115 return Bytes::get_Java_u8((address)tmp); 116 } 117 118 void ClassFileStream::skip_u1(int length, TRAPS) const { 119 if (_need_verify) { 120 guarantee_more(length, CHECK); 121 } 122 _current += length; 123 } 124 125 void ClassFileStream::skip_u2(int length, TRAPS) const { 126 if (_need_verify) { 127 guarantee_more(length * 2, CHECK); 128 } 129 _current += length * 2; 130 } 131 132 void ClassFileStream::skip_u4(int length, TRAPS) const { 133 if (_need_verify) { 134 guarantee_more(length * 4, CHECK); 135 } 136 _current += length * 4; 137 } 138 139 uint64_t ClassFileStream::compute_fingerprint() const { 140 int classfile_size = length(); 141 int classfile_crc = ClassLoader::crc32(0, (const char*)buffer(), length()); 142 uint64_t fingerprint = (uint64_t(classfile_size) << 32) | uint64_t(uint32_t(classfile_crc)); 143 assert(fingerprint != 0, "must not be zero"); 144 145 return fingerprint; 146 }