1 /*
   2  * Copyright (c) 1995, 2019, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 
  27 package sun.tools.java;
  28 
  29 import java.io.*;
  30 
  31 /**
  32  * WARNING: The contents of this source file are not part of any
  33  * supported API.  Code that depends on them does so at its own risk:
  34  * they are subject to change or removal without notice.
  35  */
  36 public class BinaryCode implements Constants {
  37     int maxStack;               // maximum stack used by code
  38     int maxLocals;              // maximum locals used by code
  39     BinaryExceptionHandler exceptionHandlers[];
  40     BinaryAttribute atts;       // code attributes
  41     BinaryConstantPool cpool;   // constant pool of the class
  42     byte code[];                // the byte code
  43 
  44     /**
  45      * Construct the binary code from the code attribute
  46      */
  47 
  48     public
  49     BinaryCode(byte data[], BinaryConstantPool cpool, Environment env) {
  50         DataInputStream in = new DataInputStream(new ByteArrayInputStream(data));
  51         try {
  52             this.cpool = cpool;
  53             // JVM 4.7.4 CodeAttribute.max_stack
  54             this.maxStack = in.readUnsignedShort();
  55             // JVM 4.7.4 CodeAttribute.max_locals
  56             this.maxLocals = in.readUnsignedShort();
  57             // JVM 4.7.4 CodeAttribute.code_length
  58             int code_length = in.readInt();
  59             this.code = new byte[code_length];
  60             // JVM 4.7.4 CodeAttribute.code[]
  61             in.read(this.code);
  62             // JVM 4.7.4 CodeAttribute.exception_table_length
  63             int exception_count = in.readUnsignedShort();
  64             this.exceptionHandlers = new BinaryExceptionHandler[exception_count];
  65             for (int i = 0; i < exception_count; i++) {
  66                 // JVM 4.7.4 CodeAttribute.exception_table.start_pc
  67                 int start = in.readUnsignedShort();
  68                 // JVM 4.7.4 CodeAttribute.exception_table.end_pc
  69                 int end = in.readUnsignedShort();
  70                 // JVM 4.7.4 CodeAttribute.exception_table.handler_pc
  71                 int handler = in.readUnsignedShort();
  72                 // JVM 4.7.4 CodeAttribute.exception_table.catch_type
  73                 ClassDeclaration xclass = cpool.getDeclaration(env, in.readUnsignedShort());
  74                 this.exceptionHandlers[i]  =
  75                     new BinaryExceptionHandler(start, end, handler, xclass);
  76             }
  77             this.atts = BinaryAttribute.load(in, cpool, ~0);
  78             if (in.available() != 0) {
  79                 System.err.println("Should have exhausted input stream!");
  80             }
  81         } catch (IOException e) {
  82             throw new CompilerError(e);
  83         }
  84     }
  85 
  86 
  87     /**
  88      * Accessors
  89      */
  90 
  91     public BinaryExceptionHandler[] getExceptionHandlers() {
  92         return exceptionHandlers;
  93     }
  94 
  95     public byte[] getCode() { return code; }
  96 
  97     public int getMaxStack() { return maxStack; }
  98 
  99     public int getMaxLocals() { return maxLocals; }
 100 
 101     public BinaryAttribute getAttributes() { return atts; }
 102 
 103     /**
 104      * Load a binary class
 105      */
 106     public static
 107     BinaryCode load(BinaryMember bf, BinaryConstantPool cpool, Environment env) {
 108         byte code[] = bf.getAttribute(idCode);
 109         return (code != null) ? new BinaryCode(code, cpool, env) : null;
 110     }
 111 }