1 /*
   2  * Copyright (c) 1997, 2014, 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/vmSymbols.hpp"
  28 
  29 void ClassFileStream::truncated_file_error(TRAPS) {
  30   THROW_MSG(vmSymbols::java_lang_ClassFormatError(), "Truncated class file");
  31 }
  32 
  33 ClassFileStream::ClassFileStream(u1* buffer, int length, const char* source, bool need_verify) {
  34   _buffer_start = buffer;
  35   _buffer_end   = buffer + length;
  36   _current      = buffer;
  37   _source       = source;
  38   _need_verify  = need_verify;
  39 }
  40 
  41 u1 ClassFileStream::get_u1(TRAPS) {
  42   if (_need_verify) {
  43     guarantee_more(1, CHECK_0);
  44   } else {
  45     assert(1 <= _buffer_end - _current, "buffer overflow");
  46   }
  47   return *_current++;
  48 }
  49 
  50 u2 ClassFileStream::get_u2(TRAPS) {
  51   if (_need_verify) {
  52     guarantee_more(2, CHECK_0);
  53   } else {
  54     assert(2 <= _buffer_end - _current, "buffer overflow");
  55   }
  56   u1* tmp = _current;
  57   _current += 2;
  58   return Bytes::get_Java_u2(tmp);
  59 }
  60 
  61 u4 ClassFileStream::get_u4(TRAPS) {
  62   if (_need_verify) {
  63     guarantee_more(4, CHECK_0);
  64   } else {
  65     assert(4 <= _buffer_end - _current, "buffer overflow");
  66   }
  67   u1* tmp = _current;
  68   _current += 4;
  69   return Bytes::get_Java_u4(tmp);
  70 }
  71 
  72 u8 ClassFileStream::get_u8(TRAPS) {
  73   if (_need_verify) {
  74     guarantee_more(8, CHECK_0);
  75   } else {
  76     assert(8 <= _buffer_end - _current, "buffer overflow");
  77   }
  78   u1* tmp = _current;
  79   _current += 8;
  80   return Bytes::get_Java_u8(tmp);
  81 }
  82 
  83 void ClassFileStream::skip_u1(int length, TRAPS) {
  84   if (_need_verify) {
  85     guarantee_more(length, CHECK);
  86   }
  87   _current += length;
  88 }
  89 
  90 void ClassFileStream::skip_u2(int length, TRAPS) {
  91   if (_need_verify) {
  92     guarantee_more(length * 2, CHECK);
  93   }
  94   _current += length * 2;
  95 }
  96 
  97 void ClassFileStream::skip_u4(int length, TRAPS) {
  98   if (_need_verify) {
  99     guarantee_more(length * 4, CHECK);
 100   }
 101   _current += length * 4;
 102 }
 103 
 104 #if INCLUDE_JFR
 105 
 106 u1* ClassFileStream::clone_buffer() const {
 107   u1* const new_buffer_start = NEW_RESOURCE_ARRAY(u1, length());
 108   memcpy(new_buffer_start, _buffer_start, length());
 109   return new_buffer_start;
 110 }
 111 
 112 const char* const ClassFileStream::clone_source() const {
 113   const char* const src = source();
 114   char* source_copy = NULL;
 115   if (src != NULL) {
 116     size_t source_len = strlen(src);
 117     source_copy = NEW_RESOURCE_ARRAY(char, source_len + 1);
 118     strncpy(source_copy, src, source_len + 1);
 119   }
 120   return source_copy;
 121 }
 122 
 123 ClassFileStream* ClassFileStream::clone() const {
 124   u1* const new_buffer_start = clone_buffer();
 125   return new ClassFileStream(new_buffer_start,
 126                              length(),
 127                              clone_source(),
 128                              need_verify());
 129 }
 130 #endif // INCLUDE_JFR