1 /* 2 * Copyright (c) 1997, 2015, 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 #ifndef SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP 26 #define SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP 27 28 #include "utilities/top.hpp" 29 #ifdef TARGET_ARCH_x86 30 # include "bytes_x86.hpp" 31 #endif 32 #ifdef TARGET_ARCH_aarch64 33 # include "bytes_aarch64.hpp" 34 #endif 35 #ifdef TARGET_ARCH_sparc 36 # include "bytes_sparc.hpp" 37 #endif 38 #ifdef TARGET_ARCH_zero 39 # include "bytes_zero.hpp" 40 #endif 41 #ifdef TARGET_ARCH_arm 42 # include "bytes_arm.hpp" 43 #endif 44 #ifdef TARGET_ARCH_ppc 45 # include "bytes_ppc.hpp" 46 #endif 47 48 // Input stream for reading .class file 49 // 50 // The entire input stream is present in a buffer allocated by the caller. 51 // The caller is responsible for deallocating the buffer and for using 52 // ResourceMarks appropriately when constructing streams. 53 54 class ClassFileStream: public ResourceObj { 55 private: 56 u1* _buffer_start; // Buffer bottom 57 u1* _buffer_end; // Buffer top (one past last element) 58 u1* _current; // Current buffer position 59 const char* _source; // Source of stream (directory name, ZIP/JAR archive name) 60 bool _need_verify; // True if verification is on for the class file 61 62 void truncated_file_error(TRAPS); 63 64 #if INCLUDE_JFR 65 u1* clone_buffer() const; 66 const char* const clone_source() const; 67 #endif 68 69 public: 70 // Constructor 71 ClassFileStream(u1* buffer, int length, const char* source, bool need_verify = false); 72 73 // Buffer access buffer() const74 u1* buffer() const { return _buffer_start; } length() const75 int length() const { return _buffer_end - _buffer_start; } current() const76 u1* current() const { return _current; } set_current(u1 * pos)77 void set_current(u1* pos) { _current = pos; } 78 // for relative positioning current_offset() const79 juint current_offset() const { 80 return (juint)(_current - _buffer_start); 81 } source() const82 const char* source() const { return _source; } set_verify(bool flag)83 void set_verify(bool flag) { _need_verify = flag; } 84 check_truncated_file(bool b,TRAPS)85 void check_truncated_file(bool b, TRAPS) { 86 if (b) { 87 truncated_file_error(THREAD); 88 } 89 } 90 guarantee_more(int size,TRAPS)91 void guarantee_more(int size, TRAPS) { 92 size_t remaining = (size_t)(_buffer_end - _current); 93 unsigned int usize = (unsigned int)size; 94 check_truncated_file(usize > remaining, CHECK); 95 } 96 97 // Read u1 from stream 98 u1 get_u1(TRAPS); get_u1_fast()99 u1 get_u1_fast() { 100 return *_current++; 101 } 102 103 // Read u2 from stream 104 u2 get_u2(TRAPS); get_u2_fast()105 u2 get_u2_fast() { 106 u2 res = Bytes::get_Java_u2(_current); 107 _current += 2; 108 return res; 109 } 110 111 // Read u4 from stream 112 u4 get_u4(TRAPS); get_u4_fast()113 u4 get_u4_fast() { 114 u4 res = Bytes::get_Java_u4(_current); 115 _current += 4; 116 return res; 117 } 118 119 // Read u8 from stream 120 u8 get_u8(TRAPS); get_u8_fast()121 u8 get_u8_fast() { 122 u8 res = Bytes::get_Java_u8(_current); 123 _current += 8; 124 return res; 125 } 126 127 // Get direct pointer into stream at current position. 128 // Returns NULL if length elements are not remaining. The caller is 129 // responsible for calling skip below if buffer contents is used. get_u1_buffer()130 u1* get_u1_buffer() { 131 return _current; 132 } 133 get_u2_buffer()134 u2* get_u2_buffer() { 135 return (u2*) _current; 136 } 137 138 // Skip length u1 or u2 elements from stream 139 void skip_u1(int length, TRAPS); skip_u1_fast(int length)140 void skip_u1_fast(int length) { 141 _current += length; 142 } 143 144 void skip_u2(int length, TRAPS); skip_u2_fast(int length)145 void skip_u2_fast(int length) { 146 _current += 2 * length; 147 } 148 149 void skip_u4(int length, TRAPS); skip_u4_fast(int length)150 void skip_u4_fast(int length) { 151 _current += 4 * length; 152 } 153 154 // Tells whether eos is reached at_eos() const155 bool at_eos() const { return _current == _buffer_end; } 156 157 #if INCLUDE_JFR 158 ClassFileStream* clone() const; 159 need_verify() const160 bool need_verify() const { return _need_verify; } 161 #endif 162 }; 163 164 #endif // SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP 165