hotspot/src/share/vm/utilities/elfStringTable.cpp
changeset 7447 32c42d627f41
child 9403 6f3c6231c20a
equal deleted inserted replaced
7397:5b173b4ca846 7447:32c42d627f41
       
     1 /*
       
     2  * Copyright (c) 1997, 2010, 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 
       
    27 #ifndef _WINDOWS
       
    28 
       
    29 #include "memory/allocation.inline.hpp"
       
    30 #include "utilities/elfStringTable.hpp"
       
    31 
       
    32 // We will try to load whole string table into memory if we can.
       
    33 // Otherwise, fallback to more expensive file operation.
       
    34 ElfStringTable::ElfStringTable(FILE* file, Elf_Shdr shdr, int index) {
       
    35   assert(file, "null file handle");
       
    36   m_table = NULL;
       
    37   m_index = index;
       
    38   m_next = NULL;
       
    39   m_file = file;
       
    40   m_status = Decoder::no_error;
       
    41 
       
    42   // try to load the string table
       
    43   long cur_offset = ftell(file);
       
    44   m_table = (char*)NEW_C_HEAP_ARRAY(char, shdr.sh_size);
       
    45   if (m_table != NULL) {
       
    46     // if there is an error, mark the error
       
    47     if (fseek(file, shdr.sh_offset, SEEK_SET) ||
       
    48       fread((void*)m_table, shdr.sh_size, 1, file) != 1 ||
       
    49       fseek(file, cur_offset, SEEK_SET)) {
       
    50       m_status = Decoder::file_invalid;
       
    51       FREE_C_HEAP_ARRAY(char, m_table);
       
    52       m_table = NULL;
       
    53     }
       
    54   } else {
       
    55     memcpy(&m_shdr, &shdr, sizeof(Elf_Shdr));
       
    56   }
       
    57 }
       
    58 
       
    59 ElfStringTable::~ElfStringTable() {
       
    60   if (m_table != NULL) {
       
    61     FREE_C_HEAP_ARRAY(char, m_table);
       
    62   }
       
    63 
       
    64   if (m_next != NULL) {
       
    65     delete m_next;
       
    66   }
       
    67 }
       
    68 
       
    69 const char* ElfStringTable::string_at(int pos) {
       
    70   if (m_status != Decoder::no_error) {
       
    71     return NULL;
       
    72   }
       
    73   if (m_table != NULL) {
       
    74     return (const char*)(m_table + pos);
       
    75   } else {
       
    76     long cur_pos = ftell(m_file);
       
    77     if (cur_pos == -1 ||
       
    78       fseek(m_file, m_shdr.sh_offset + pos, SEEK_SET) ||
       
    79       fread(m_symbol, 1, MAX_SYMBOL_LEN, m_file) <= 0 ||
       
    80       fseek(m_file, cur_pos, SEEK_SET)) {
       
    81       m_status = Decoder::file_invalid;
       
    82       return NULL;
       
    83     }
       
    84     return (const char*)m_symbol;
       
    85   }
       
    86 }
       
    87 
       
    88 #endif // _WINDOWS
       
    89