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
truncated_file_error(TRAPS) const35 void ClassFileStream::truncated_file_error(TRAPS) const {
36 THROW_MSG(vmSymbols::java_lang_ClassFormatError(), "Truncated class file");
37 }
38
ClassFileStream(const u1 * buffer,int length,const char * source,bool verify_stream)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
clone_buffer() const49 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
clone_source() const55 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
clone() const68 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
get_u1(TRAPS) const76 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
get_u2(TRAPS) const85 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
get_u4(TRAPS) const96 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
get_u8(TRAPS) const107 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
skip_u1(int length,TRAPS) const118 void ClassFileStream::skip_u1(int length, TRAPS) const {
119 if (_need_verify) {
120 guarantee_more(length, CHECK);
121 }
122 _current += length;
123 }
124
skip_u2(int length,TRAPS) const125 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
skip_u4(int length,TRAPS) const132 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
compute_fingerprint() const139 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 }
147