1 /*
   2  * Copyright (c) 2017, 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 
  26 package jdk.tools.jaotc.binformat.pecoff;
  27 
  28 import java.nio.ByteBuffer;
  29 import java.nio.ByteOrder;
  30 import java.util.ArrayList;
  31 
  32 import jdk.tools.jaotc.binformat.pecoff.PECoff.IMAGE_SYMBOL;
  33 
  34 final class PECoffSymtab {
  35     ArrayList<PECoffSymbol> symbols = new ArrayList<>();
  36 
  37     /**
  38      * Number of symbols added.
  39      */
  40     private int symbolCount;
  41 
  42     /**
  43      * String holding symbol table strings.
  44      */
  45     private final StringBuilder strTabContent;
  46 
  47     /**
  48      * Keeps track of bytes in string table since strTabContent.length() is number of chars, not
  49      * bytes.
  50      */
  51     private int strTabNrOfBytes;
  52 
  53     /**
  54      * String holding Linker Directives.
  55      */
  56     private final StringBuilder directives;
  57 
  58     PECoffSymtab() {
  59         symbolCount = 0;
  60         strTabContent = new StringBuilder();
  61         directives = new StringBuilder();
  62 
  63         // The first 4 bytes of the string table contain
  64         // the length of the table (including this length field).
  65         strTabNrOfBytes = 4;
  66 
  67         // Make room for the 4 byte length field
  68         strTabContent.append('\0').append('\0').append('\0').append('\0');
  69 
  70         // Linker Directives start with 3 spaces to signify ANSI
  71         directives.append("   ");
  72     }
  73 
  74     PECoffSymbol addSymbolEntry(String name, byte type, byte storageclass, byte secHdrIndex, long offset) {
  75         // Get the current symbol index and append symbol name to string table.
  76         int index;
  77         PECoffSymbol sym;
  78 
  79         if (name.isEmpty()) {
  80             index = 0;
  81             strTabContent.append('\0');
  82             strTabNrOfBytes += 1;
  83             sym = new PECoffSymbol(symbolCount, index, type, storageclass, secHdrIndex, offset);
  84             symbols.add(sym);
  85         } else {
  86             int nameSize = name.getBytes().length;
  87 
  88             // We can't trust strTabContent.length() since that is
  89             // chars (UTF16), keep track of bytes on our own.
  90             index = strTabNrOfBytes;
  91             // strTabContent.append('_').append(name).append('\0');
  92             strTabContent.append(name).append('\0');
  93             strTabNrOfBytes += (nameSize + 1);
  94 
  95             sym = new PECoffSymbol(symbolCount, index, type, storageclass, secHdrIndex, offset);
  96             symbols.add(sym);
  97             if (storageclass == IMAGE_SYMBOL.IMAGE_SYM_CLASS_EXTERNAL) {
  98                 addDirective(name, type);
  99             }
 100         }
 101         symbolCount++;
 102         return (sym);
 103     }
 104 
 105     private void addDirective(String name, byte type) {
 106         directives.append("/EXPORT:" + name);
 107         if (type != IMAGE_SYMBOL.IMAGE_SYM_DTYPE_FUNCTION) {
 108             directives.append(",DATA");
 109         }
 110         directives.append(" ");
 111     }
 112 
 113     int getSymtabCount() {
 114         return symbolCount;
 115     }
 116 
 117     int getStrtabSize() {
 118         return strTabNrOfBytes;
 119     }
 120 
 121     // Return a byte array that contains the symbol table entries
 122     byte[] getSymtabArray() {
 123         ByteBuffer symtabData = PECoffByteBuffer.allocate(symbolCount * IMAGE_SYMBOL.totalsize);
 124         symtabData.order(ByteOrder.LITTLE_ENDIAN);
 125 
 126         // copy all symbols
 127         for (int i = 0; i < symbolCount; i++) {
 128             PECoffSymbol sym = symbols.get(i);
 129             byte[] arr = sym.getArray();
 130             symtabData.put(arr);
 131         }
 132         return (symtabData.array());
 133     }
 134 
 135     // Return the string table array
 136     byte[] getStrtabArray() {
 137         byte[] strs = strTabContent.toString().getBytes();
 138 
 139         // Update the size of the string table
 140         ByteBuffer buff = ByteBuffer.wrap(strs);
 141         buff.order(ByteOrder.LITTLE_ENDIAN);
 142         buff.putInt(0, strTabNrOfBytes);
 143 
 144         return (strs);
 145     }
 146 
 147     byte[] getDirectiveArray() {
 148         return (directives.toString().getBytes());
 149     }
 150 }