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
32const bool ClassFileStream::verify = true;
33const bool ClassFileStream::no_verification = false;
34
35void ClassFileStream::truncated_file_error(TRAPS) const {
36  THROW_MSG(vmSymbols::java_lang_ClassFormatError(), "Truncated class file");
37}
38
39ClassFileStream::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
49const 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
55const 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
68const 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
76u1 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
85u2 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
96u4 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
107u8 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
118void ClassFileStream::skip_u1(int length, TRAPS) const {
119  if (_need_verify) {
120    guarantee_more(length, CHECK);
121  }
122  _current += length;
123}
124
125void ClassFileStream::skip_u2(int length, TRAPS) const {
126  if (_need_verify) {
127    guarantee_more(length * 2, CHECK);
128  }
129  _current += length * 2;
130}
131
132void ClassFileStream::skip_u4(int length, TRAPS) const {
133  if (_need_verify) {
134    guarantee_more(length * 4, CHECK);
135  }
136  _current += length * 4;
137}
138
139uint64_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