gold/freebsd.h

   1 // freebsd.h -- FreeBSD support for gold    -*- C++ -*-
   2
   3 // Copyright 2009 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 #include "target.h"
  24 #include "target-select.h"
  25
  26 #ifndef GOLD_FREEBSD_H
  27 #define GOLD_FREEBSD_H
  28
  29 namespace gold
  30 {
  31
  32 // FreeBSD 4.1 and later wants the EI_OSABI field in the ELF header to
  33 // be set to ELFOSABI_FREEBSD.  This is a subclass of Sized_target
  34 // which supports that.  The real target would be a subclass of this
  35 // one.  We permit combining FreeBSD and non-FreeBSD object files.
  36 // The effect of this target is to set the code in the output file.
  37
  38 template<int size, bool big_endian>
  39 class Target_freebsd : public Sized_target<size, big_endian>
  40 {
  41  public:
  42   // Set the value to use for the EI_OSABI field in the ELF header.
  43   void
  44   set_osabi(elfcpp::ELFOSABI osabi)
  45   { this->osabi_ = osabi; }
  46
  47  protected:
  48   Target_freebsd(const Target::Target_info* pti)
  49     : Sized_target<size, big_endian>(pti),
  50       osabi_(elfcpp::ELFOSABI_NONE)
  51   { }
  52
  53   virtual void
  54   do_adjust_elf_header(unsigned char* view, int len) const;
  55
  56  private:
  57   // Value to store in the EI_OSABI field of the ELF file header.
  58   elfcpp::ELFOSABI osabi_;
  59 };
  60
  61 // Adjust the ELF file header by storing the requested value in the
  62 // OSABI field.  This is for FreeBSD support.
  63
  64 template<int size, bool big_endian>
  65 inline void
  66 Target_freebsd<size, big_endian>::do_adjust_elf_header(unsigned char* view,
  67                                                        int len) const
  68 {
  69   if (this->osabi_ != elfcpp::ELFOSABI_NONE)
  70     {
  71       gold_assert(len == elfcpp::Elf_sizes<size>::ehdr_size);
  72
  73       elfcpp::Ehdr<size, false> ehdr(view);
  74       unsigned char e_ident[elfcpp::EI_NIDENT];
  75       memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
  76
  77       e_ident[elfcpp::EI_OSABI] = this->osabi_;
  78
  79       elfcpp::Ehdr_write<size, false> oehdr(view);
  80       oehdr.put_e_ident(e_ident);
  81     }
  82 }
  83
  84 // A target selector for targets which permit combining both FreeBSD
  85 // and non-FreeBSD object files.
  86
  87 class Target_selector_freebsd : public Target_selector
  88 {
  89  public:
  90   Target_selector_freebsd(int machine, int size, bool is_big_endian,
  91                           const char* bfd_name,
  92                           const char* freebsd_bfd_name)
  93     : Target_selector(machine, size, is_big_endian, NULL),
  94       bfd_name_(bfd_name), freebsd_bfd_name_(freebsd_bfd_name)
  95   { }
  96
  97  protected:
  98   // If we see a FreeBSD input file, mark the output file as using
  99   // FreeBSD.
 100   virtual Target*
 101   do_recognize(int, int osabi, int)
 102   {
 103     Target* ret = this->instantiate_target();
 104     if (osabi == elfcpp::ELFOSABI_FREEBSD)
 105       this->set_osabi(ret);
 106     return ret;
 107   }
 108
 109   // Recognize two names.
 110   virtual Target*
 111   do_recognize_by_name(const char* name)
 112   {
 113     if (strcmp(name, this->bfd_name_) == 0)
 114       return this->instantiate_target();
 115     else if (strcmp(name, this->freebsd_bfd_name_) == 0)
 116       {
 117         Target* ret = this->instantiate_target();
 118         this->set_osabi(ret);
 119         return ret;
 120       }
 121     else
 122       return NULL;
 123   }
 124
 125   // Print both names in --help output.
 126   virtual void
 127   do_supported_names(std::vector<const char*>* names)
 128   {
 129     names->push_back(this->bfd_name_);
 130     names->push_back(this->freebsd_bfd_name_);
 131   }
 132
 133  private:
 134   // Set the OSABI field.  This is quite ugly.
 135   void
 136   set_osabi(Target* target)
 137   {
 138     if (this->get_size() == 32)
 139       {
 140         if (this->is_big_endian())
 141           static_cast<Target_freebsd<32, true>*>(target)->
 142             set_osabi(elfcpp::ELFOSABI_FREEBSD);
 143         else
 144           static_cast<Target_freebsd<32, false>*>(target)->
 145             set_osabi(elfcpp::ELFOSABI_FREEBSD);
 146       }
 147     else if (this->get_size() == 64)
 148       {
 149         if (this->is_big_endian())
 150           static_cast<Target_freebsd<64, true>*>(target)->
 151             set_osabi(elfcpp::ELFOSABI_FREEBSD);
 152         else
 153           static_cast<Target_freebsd<64, false>*>(target)->
 154             set_osabi(elfcpp::ELFOSABI_FREEBSD);
 155       }
 156     else
 157       gold_unreachable();
 158   }
 159
 160   // The BFD name for the non-Freebsd target.
 161   const char* bfd_name_;
 162   // The BFD name for the Freebsd target.
 163   const char* freebsd_bfd_name_;
 164 };
 165
 166 } // end namespace gold
 167
 168 #endif // !defined(GOLD_FREEBSD_H)