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
29namespace 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
38template<int size, bool big_endian>
39class 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
64template<int size, bool big_endian>
65inline void
66Target_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
87class 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)
169