code: /**
   * Copyright (c) 2005, Regents of the University of California
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   *
   * Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   *
   * Neither the name of the University of California, Los Angeles nor the
   * names of its contributors may be used to endorse or promote products
   * derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * Created Sep 5, 2005
   */
  package cck.elf;
  
  import java.io.IOException;
  import java.io.RandomAccessFile;
  
  /**
   * The <code>ELFSymbolTable</code> class represents a symbol table within
   * an ELF file. The symbol table is used to locate functions and variables
   * for relocation and debugging purposes.
   *
   * @author Ben L. Titzer
   */
  public class ELFSymbolTable {
  
      public static final int STT_NOTYPE  = 0;
      public static final int STT_OBJECT  = 1;
      public static final int STT_FUNC    = 2;
      public static final int STT_SECTION = 3;
      public static final int STT_FILE    = 4;
      public static final int STT_LOPROC  = 13;
      public static final int STT_HIPROC  = 15;
  
      public static final int STB_LOCAL = 0;
      public static final int STB_GLOBAL = 1;
      public static final int STB_WEAK = 2;
      public static final int STB_LOPROC = 13;
      public static final int STB_HIPROC = 15;
  
      public class Entry {
          public int st_name;
          public int st_value;
          public int st_size;
          public int st_info;
          public int st_other;
          public short st_shndx;
  
          public String getBinding() {
              switch ( (st_info >> 4) & 0xf ) {
                  case STB_LOCAL: return "LOCAL";
                  case STB_GLOBAL: return "GLOBAL";
                  case STB_WEAK: return "WEAK";
                  default: return "unknown";
              }
          }
  
          public String getType() {
              switch ( st_info & 0xf ) {
                  case STT_NOTYPE: return "n";
                  case STT_OBJECT: return "object";
                  case STT_FUNC: return "func";
                  case STT_SECTION: return "section";
                  case STT_FILE: return "file";
                  default: return "unknown";
              }
          }
  
          public boolean isFunction() {
              return (st_info & 0xf) == STT_FUNC;
          }
  
          public boolean isObject() {
              return (st_info & 0xf) == STT_OBJECT;
          }
  
          public String getName() {
              if ( strtab != null ) return strtab.getString(st_name);
              return "";
          }
  
      }
  
      public final ELFHeader header;
      public final ELFSectionHeaderTable.Entry32 entry;
      public final Entry[] entries;
      protected ELFStringTable strtab;
  
      /**
       * The constructor for the <code>ELFSymbolTable</code> class creates a new
       * symbol table with the specified ELF header from the specified ELF section
       * header table entry.
       * @param header the header of the ELF file
       * @param entry the entry in the section header table corresponding to this
       * symbol table
       */
      public ELFSymbolTable(ELFHeader header, ELFSectionHeaderTable.Entry32 entry) {
          this.header = header;
          this.entry = entry;
          entries = new Entry[entry.sh_size / entry.sh_entsize];
      }
  
      /**
       * The <code>read()</code> method reads this symbol table from the specified random
       * access file. The file is first advanced to the appropriate position with the
       * <code>seek()</code> method and then the entries are loaded.
       * @param f the random access file from which to read the symbol table
       * @throws IOException if there is a problem reading from the file
       */
      public void read(RandomAccessFile f) throws IOException {
          // seek to the beginning of the section
          f.seek(entry.sh_offset);
          // create the elf data input stream
          ELFDataInputStream is = new ELFDataInputStream(header, f);
          // read each of the entries
          for ( int cntr = 0; cntr < entries.length; cntr++ ) {
              Entry e = new Entry();
              e.st_name = is.read_Elf32_Word();
              e.st_value = is.read_Elf32_Addr();
              e.st_size = is.read_Elf32_Word();
              e.st_info = is.read_Elf32_uchar();
              e.st_other = is.read_Elf32_uchar();
              e.st_shndx = is.read_Elf32_Half();
              entries[cntr] = e;
              for ( int pad = 16; pad < entry.sh_entsize; pad++ ) f.read();
          }
      }
  
      public void setStringTable(ELFStringTable str) {
          strtab = str;
      }
  
      public ELFStringTable getStringTable() {
          return strtab;
      }
  }
  