1 /* 2 * Copyright (c) 2017, 2018, 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.elf; 27 28 import java.nio.ByteBuffer; 29 import java.util.ArrayList; 30 31 import jdk.tools.jaotc.binformat.elf.Elf.Elf64_Sym; 32 33 final class ElfSymtab { 34 35 private final ArrayList<ElfSymbol> localSymbols = new ArrayList<>(); 36 private final ArrayList<ElfSymbol> globalSymbols = new ArrayList<>(); 37 38 /** 39 * Number of symbols added. 40 */ 41 private int symbolCount; 42 43 /** 44 * String holding symbol table strings. 45 */ 46 private final StringBuilder strTabContent = new StringBuilder(); 47 48 /** 49 * Keeps track of bytes in string table since strTabContent.length() is number of chars, not 50 * bytes. 51 */ 52 private int strTabNrOfBytes = 0; 53 54 ElfSymtab() { 55 symbolCount = 0; 56 } 57 58 ElfSymbol addSymbolEntry(String name, byte type, byte bind, byte secHdrIndex, long offset, long size) { 59 // Get the current symbol index and append symbol name to string table. 60 int index; 61 ElfSymbol sym; 62 63 if (name.isEmpty()) { 64 index = 0; 65 strTabContent.append('\0'); 66 strTabNrOfBytes += 1; 67 sym = new ElfSymbol(symbolCount, index, type, bind, secHdrIndex, offset, size); 68 localSymbols.add(sym); 69 } else { 70 // We can't trust strTabContent.length() since that is 71 // chars (UTF16), keep track of bytes on our own. 72 index = strTabNrOfBytes; 73 // strTabContent.append("_").append(name).append('\0'); 74 strTabContent.append(name).append('\0'); 75 // + 1 for null, + 1 for "_" 76 // strTabNrOfBytes += (name.getBytes().length + 1 + 1); 77 strTabNrOfBytes += (name.getBytes().length + 1); 78 79 sym = new ElfSymbol(symbolCount, index, type, bind, secHdrIndex, offset, size); 80 if ((bind & Elf64_Sym.STB_GLOBAL) != 0) { 81 globalSymbols.add(sym); 82 } else { 83 localSymbols.add(sym); 84 } 85 } 86 symbolCount++; 87 return (sym); 88 } 89 90 // Update the symbol indexes once all symbols have been added. 91 // This is required since we'll be reordering the symbols in the 92 // file to be in the order of Local then global. 93 void updateIndexes() { 94 int index = 0; 95 96 // Update the local symbol indexes 97 for (int i = 0; i < localSymbols.size(); i++) { 98 ElfSymbol sym = localSymbols.get(i); 99 sym.setIndex(index++); 100 } 101 102 // Update the global symbol indexes 103 for (int i = 0; i < globalSymbols.size(); i++) { 104 ElfSymbol sym = globalSymbols.get(i); 105 sym.setIndex(index++); 106 } 107 } 108 109 int getNumLocalSyms() { 110 return localSymbols.size(); 111 } 112 113 int getNumGlobalSyms() { 114 return globalSymbols.size(); 115 } 116 117 // Create a single byte array that contains the symbol table entries 118 byte[] getSymtabArray() { 119 ByteBuffer symtabData = ElfByteBuffer.allocate(symbolCount * Elf64_Sym.totalsize); 120 byte[] retarray; 121 122 updateIndexes(); 123 124 // Add the local symbols 125 for (int i = 0; i < localSymbols.size(); i++) { 126 ElfSymbol sym = localSymbols.get(i); 127 byte[] arr = sym.getArray(); 128 symtabData.put(arr); 129 } 130 // Add the global symbols 131 for (int i = 0; i < globalSymbols.size(); i++) { 132 ElfSymbol sym = globalSymbols.get(i); 133 byte[] arr = sym.getArray(); 134 symtabData.put(arr); 135 } 136 retarray = symtabData.array(); 137 138 return (retarray); 139 } 140 141 // Return the string table array 142 byte[] getStrtabArray() { 143 byte[] strs = strTabContent.toString().getBytes(); 144 return (strs); 145 } 146 }