gold/ehframe.h

   1 // ehframe.h -- handle exception frame sections for gold  -*- C++ -*-
   2
   3 // Copyright 2006, 2007 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #ifndef GOLD_EHFRAME_H
  24 #define GOLD_EHFRAME_H
  25
  26 #include "output.h"
  27
  28 namespace gold
  29 {
  30
  31 // This class manages the .eh_frame_hdr section, which holds the data
  32 // for the PT_GNU_EH_FRAME segment.  gcc's unwind support code uses
  33 // the PT_GNU_EH_FRAME segment to find the list of FDEs.  This saves
  34 // the time required to register the exception handlers at startup
  35 // time and when a shared object is loaded, and the time required to
  36 // deregister the exception handlers when a shared object is unloaded.
  37
  38 // FIXME: gcc supports using storing a sorted lookup table for the
  39 // FDEs in the PT_GNU_EH_FRAME segment, but we do not yet generate
  40 // that.
  41
  42 class Eh_frame_hdr : public Output_section_data
  43 {
  44  public:
  45   Eh_frame_hdr(const Target*, Output_section* eh_frame_section);
  46
  47   // Set the final data size.
  48   void
  49   do_set_address(uint64_t address, off_t offset);
  50
  51   // Write the data to the file.
  52   void
  53   do_write(Output_file*);
  54
  55  private:
  56   // The output target.
  57   const Target* target_;
  58   // The .eh_frame section.
  59   Output_section* eh_frame_section_;
  60 };
  61
  62 } // End namespace gold.
  63
  64 #endif // !defined(GOLD_EHFRAME_H)