[deliverable/binutils-gdb.git] / gold / gc.h

// gc.h -- garbage collection of unused sections

// Copyright 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
// Written by Sriraman Tallam <tmsriram@google.com>.

// This file is part of gold.

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.

#ifndef GOLD_GC_H
#define GOLD_GC_H

#include <queue>
#include <vector>

#include "elfcpp.h"
#include "symtab.h"
#include "object.h"
#include "icf.h"

namespace gold
{

class Object;

template<int size, bool big_endian>
class Sized_relobj_file;

template<int sh_type, int size, bool big_endian>
struct Reloc_types;

class Output_section;
class General_options;
class Layout;

class Garbage_collection
{
 public:

  typedef Unordered_set<Section_id, Section_id_hash> Sections_reachable;
  typedef std::map<Section_id, Sections_reachable> Section_ref;
  typedef std::queue<Section_id> Worklist_type;
  // This maps the name of the section which can be represented as a C
  // identifier (cident) to the list of sections that have that name.
  // Different object files can have cident sections with the same name.
  typedef std::map<std::string, Sections_reachable> Cident_section_map;

  Garbage_collection()
  : is_worklist_ready_(false)
  { }

  // Accessor methods for the private members.

  Sections_reachable&
  referenced_list()
  { return referenced_list_; }

  Section_ref&
  section_reloc_map()
  { return this->section_reloc_map_; }

  Worklist_type&
  worklist()
  { return this->work_list_; }

  bool
  is_worklist_ready()
  { return this->is_worklist_ready_; }

  void
  worklist_ready()
  { this->is_worklist_ready_ = true; }

  void
  do_transitive_closure();

  bool
  is_section_garbage(Object* obj, unsigned int shndx)
  { return (this->referenced_list().find(Section_id(obj, shndx))
            == this->referenced_list().end()); }

  Cident_section_map*
  cident_sections()
  { return &cident_sections_; }

  void
  add_cident_section(std::string section_name,
		     Section_id secn)
  { this->cident_sections_[section_name].insert(secn); }

  // Add a reference from the SRC_SHNDX-th section of SRC_OBJECT to
  // DST_SHNDX-th section of DST_OBJECT.
  void
  add_reference(Object* src_object, unsigned int src_shndx,
		Object* dst_object, unsigned int dst_shndx)
  {
    Section_id src_id(src_object, src_shndx);
    Section_id dst_id(dst_object, dst_shndx);
    Section_ref::iterator p = this->section_reloc_map_.find(src_id);
    if (p == this->section_reloc_map_.end())
      this->section_reloc_map_[src_id].insert(dst_id);
    else
      p->second.insert(dst_id);
  }

 private:

  Worklist_type work_list_;
  bool is_worklist_ready_;
  Section_ref section_reloc_map_;
  Sections_reachable referenced_list_;
  Cident_section_map cident_sections_;
};

// Data to pass between successive invocations of do_layout
// in object.cc while garbage collecting.  This data structure
// is filled by using the data from Read_symbols_data.

struct Symbols_data
{
  // Section headers.
  unsigned char* section_headers_data;
  // Section names.
  unsigned char* section_names_data;
  // Size of section name data in bytes.
  section_size_type section_names_size;
  // Symbol data.
  unsigned char* symbols_data;
  // Size of symbol data in bytes.
  section_size_type symbols_size;
  // Offset of external symbols within symbol data.  This structure
  // sometimes contains only external symbols, in which case this will
  // be zero.  Sometimes it contains all symbols.
  section_offset_type external_symbols_offset;
  // Symbol names.
  unsigned char* symbol_names_data;
  // Size of symbol name data in bytes.
  section_size_type symbol_names_size;
};

// Relocations of type SHT_REL store the addend value in their bytes.
// This function returns the size of the embedded addend which is
// nothing but the size of the relocation.

template<typename Classify_reloc>
inline unsigned int
get_embedded_addend_size(int sh_type, int r_type, Relobj* obj)
{
  if (sh_type != elfcpp::SHT_REL)
    return 0;
  Classify_reloc classify_reloc;
  return classify_reloc.get_size_for_reloc(r_type, obj);
}

// This function implements the generic part of reloc
// processing to map a section to all the sections it
// references through relocs.  It is called only during
// garbage collection (--gc-sections) and identical code
// folding (--icf).

template<int size, bool big_endian, typename Target_type, int sh_type,
	 typename Scan, typename Classify_reloc>
inline void
gc_process_relocs(
    Symbol_table* symtab,
    Layout*,
    Target_type* target,
    Sized_relobj_file<size, big_endian>* src_obj,
    unsigned int src_indx,
    const unsigned char* prelocs,
    size_t reloc_count,
    Output_section*,
    bool,
    size_t local_count,
    const unsigned char* plocal_syms)
{
  Scan scan;

  typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
  const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
  const int sym_size = elfcpp::Elf_sizes<size>::sym_size;

  Icf::Sections_reachable_info* secvec = NULL;
  Icf::Symbol_info* symvec = NULL;
  Icf::Addend_info* addendvec = NULL;
  Icf::Offset_info* offsetvec = NULL;
  Icf::Reloc_addend_size_info* reloc_addend_size_vec = NULL;
  bool is_icf_tracked = false;
  const char* cident_section_name = NULL;

  std::string src_section_name = (parameters->options().icf_enabled()
                                  ? src_obj->section_name(src_indx)
                                  : "");

  bool check_section_for_function_pointers = false;

  if (parameters->options().icf_enabled()
      && is_section_foldable_candidate(src_section_name.c_str()))
    {
      is_icf_tracked = true;
      Section_id src_id(src_obj, src_indx);
      Icf::Reloc_info* reloc_info =
        &symtab->icf()->reloc_info_list()[src_id];
      secvec = &reloc_info->section_info;
      symvec = &reloc_info->symbol_info;
      addendvec = &reloc_info->addend_info;
      offsetvec = &reloc_info->offset_info;
      reloc_addend_size_vec = &reloc_info->reloc_addend_size_info;
    }

  check_section_for_function_pointers =
    symtab->icf()->check_section_for_function_pointers(src_section_name,
                                                       target);

  for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
    {
      Reltype reloc(prelocs);
      typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
      unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
      unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
      typename elfcpp::Elf_types<size>::Elf_Swxword addend =
      Reloc_types<sh_type, size, big_endian>::get_reloc_addend_noerror(&reloc);
      Object* dst_obj;
      unsigned int dst_indx;
      typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
      Address dst_off;

      if (r_sym < local_count)
        {
          gold_assert(plocal_syms != NULL);
          typename elfcpp::Sym<size, big_endian> lsym(plocal_syms
                                                      + r_sym * sym_size);
	  dst_indx = lsym.get_st_shndx();
          bool is_ordinary;
	  dst_indx = src_obj->adjust_sym_shndx(r_sym, dst_indx, &is_ordinary);
          dst_obj = src_obj;
	  dst_off = lsym.get_st_value() + addend;

          if (is_icf_tracked)
            {
	      Address symvalue = dst_off - addend;
	      if (is_ordinary) 
		(*secvec).push_back(Section_id(dst_obj, dst_indx));
	      else
                (*secvec).push_back(Section_id(NULL, 0));
              (*symvec).push_back(NULL);
	      (*addendvec).push_back(std::make_pair(
					static_cast<long long>(symvalue),
					static_cast<long long>(addend)));
              uint64_t reloc_offset =
                convert_to_section_size_type(reloc.get_r_offset());
	      (*offsetvec).push_back(reloc_offset);
              (*reloc_addend_size_vec).push_back(
                get_embedded_addend_size<Classify_reloc>(sh_type, r_type,
                                                         src_obj));
            }

	  // When doing safe folding, check to see if this relocation is that
	  // of a function pointer being taken.
	  if (is_ordinary
	      && check_section_for_function_pointers
              && lsym.get_st_type() != elfcpp::STT_OBJECT
 	      && scan.local_reloc_may_be_function_pointer(symtab, NULL, NULL,
							  src_obj, src_indx,
			                       		  NULL, reloc, r_type,
							  lsym))
            symtab->icf()->set_section_has_function_pointers(
              src_obj, lsym.get_st_shndx());

          if (!is_ordinary || dst_indx == src_indx)
            continue;
        }
      else
        {
          Symbol* gsym = src_obj->global_symbol(r_sym);
          gold_assert(gsym != NULL);
          if (gsym->is_forwarder())
            gsym = symtab->resolve_forwards(gsym);

          dst_obj = NULL;
          dst_indx = 0;
          bool is_ordinary = false;
          if (gsym->source() == Symbol::FROM_OBJECT)
            {
              dst_obj = gsym->object();
              dst_indx = gsym->shndx(&is_ordinary);
            }
	  dst_off = static_cast<const Sized_symbol<size>*>(gsym)->value();
	  dst_off += addend;

	  // When doing safe folding, check to see if this relocation is that
	  // of a function pointer being taken.
	  if (gsym->source() == Symbol::FROM_OBJECT
              && check_section_for_function_pointers
              && gsym->type() != elfcpp::STT_OBJECT
              && (!is_ordinary
                  || scan.global_reloc_may_be_function_pointer(
                       symtab, NULL, NULL, src_obj, src_indx, NULL, reloc,
                       r_type, gsym)))
            symtab->icf()->set_section_has_function_pointers(dst_obj, dst_indx);

          // If the symbol name matches '__start_XXX' then the section with
          // the C identifier like name 'XXX' should not be garbage collected.
          // A similar treatment to symbols with the name '__stop_XXX'.
          if (is_prefix_of(cident_section_start_prefix, gsym->name()))
            {
              cident_section_name = (gsym->name() 
                                     + strlen(cident_section_start_prefix));
            }
          else if (is_prefix_of(cident_section_stop_prefix, gsym->name()))
            {
              cident_section_name = (gsym->name() 
                                     + strlen(cident_section_stop_prefix));
            }
          if (is_icf_tracked)
            {
	      Address symvalue = dst_off - addend;
              if (is_ordinary && gsym->source() == Symbol::FROM_OBJECT)
		(*secvec).push_back(Section_id(dst_obj, dst_indx));
	      else
                (*secvec).push_back(Section_id(NULL, 0));
              (*symvec).push_back(gsym);
	      (*addendvec).push_back(std::make_pair(
					static_cast<long long>(symvalue),
					static_cast<long long>(addend)));
              uint64_t reloc_offset =
                convert_to_section_size_type(reloc.get_r_offset());
	      (*offsetvec).push_back(reloc_offset);
              (*reloc_addend_size_vec).push_back(
                get_embedded_addend_size<Classify_reloc>(sh_type, r_type,
                                                         src_obj));
	    }

          if (gsym->source() != Symbol::FROM_OBJECT)
            continue;
          if (!is_ordinary)
            continue;
        }
      if (parameters->options().gc_sections())
        {
	  symtab->gc()->add_reference(src_obj, src_indx, dst_obj, dst_indx);
	  parameters->sized_target<size, big_endian>()
	    ->gc_add_reference(symtab, src_obj, src_indx,
			       dst_obj, dst_indx, dst_off);
          if (cident_section_name != NULL)
            {
              Garbage_collection::Cident_section_map::iterator ele =
                symtab->gc()->cident_sections()->find(std::string(cident_section_name));
              if (ele == symtab->gc()->cident_sections()->end())
                continue;
	      Section_id src_id(src_obj, src_indx);
              Garbage_collection::Sections_reachable&
                v(symtab->gc()->section_reloc_map()[src_id]);
              Garbage_collection::Sections_reachable& cident_secn(ele->second);
              for (Garbage_collection::Sections_reachable::iterator it_v
                     = cident_secn.begin();
                   it_v != cident_secn.end();
                   ++it_v)
                {
                  v.insert(*it_v);
                }
            }
        }
    }
  return;
}

} // End of namespace gold.

#endif
Commit	Line	Data
6d03d481 ST	1	// gc.h -- garbage collection of unused sections
6d03d481 ST	2
2c54b4f4	3	// Copyright 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
6d03d481 ST	4	// Written by Sriraman Tallam <tmsriram@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_GC_H
	24	#define GOLD_GC_H
	25
	26	#include <queue>
ef15dade	27	#include <vector>
6d03d481 ST	28
	29	#include "elfcpp.h"
	30	#include "symtab.h"
5ac169d4	31	#include "object.h"
f345227a	32	#include "icf.h"
6d03d481 ST	33
	34	namespace gold
	35	{
	36
	37	class Object;
	38
	39	template<int size, bool big_endian>
6fa2a40b	40	class Sized_relobj_file;
6d03d481 ST	41
6d03d481 ST	42	template<int sh_type, int size, bool big_endian>
2c54b4f4	43	struct Reloc_types;
6d03d481 ST	44
	45	class Output_section;
	46	class General_options;
	47	class Layout;
	48
6d03d481 ST	49	class Garbage_collection
6d03d481 ST	50	{
ef15dade ST	51	public:
ef15dade ST	52
6d03d481 ST	53	typedef Unordered_set<Section_id, Section_id_hash> Sections_reachable;
	54	typedef std::map<Section_id, Sections_reachable> Section_ref;
	55	typedef std::queue<Section_id> Worklist_type;
f1ec9ded ST	56	// This maps the name of the section which can be represented as a C
	57	// identifier (cident) to the list of sections that have that name.
	58	// Different object files can have cident sections with the same name.
	59	typedef std::map<std::string, Sections_reachable> Cident_section_map;
6d03d481	60
ef15dade ST	61	Garbage_collection()
	62	: is_worklist_ready_(false)
	63	{ }
	64
	65	// Accessor methods for the private members.
	66
	67	Sections_reachable&
	68	referenced_list()
	69	{ return referenced_list_; }
	70
	71	Section_ref&
	72	section_reloc_map()
	73	{ return this->section_reloc_map_; }
	74
	75	Worklist_type&
	76	worklist()
	77	{ return this->work_list_; }
	78
	79	bool
	80	is_worklist_ready()
	81	{ return this->is_worklist_ready_; }
	82
	83	void
	84	worklist_ready()
	85	{ this->is_worklist_ready_ = true; }
	86
	87	void
	88	do_transitive_closure();
	89
	90	bool
	91	is_section_garbage(Object* obj, unsigned int shndx)
	92	{ return (this->referenced_list().find(Section_id(obj, shndx))
	93	== this->referenced_list().end()); }
f1ec9ded ST	94
	95	Cident_section_map*
	96	cident_sections()
	97	{ return &cident_sections_; }
	98
	99	void
	100	add_cident_section(std::string section_name,
	101	Section_id secn)
	102	{ this->cident_sections_[section_name].insert(secn); }
	103
99e5bff2 DK	104	// Add a reference from the SRC_SHNDX-th section of SRC_OBJECT to
	105	// DST_SHNDX-th section of DST_OBJECT.
	106	void
	107	add_reference(Object* src_object, unsigned int src_shndx,
	108	Object* dst_object, unsigned int dst_shndx)
	109	{
	110	Section_id src_id(src_object, src_shndx);
	111	Section_id dst_id(dst_object, dst_shndx);
	112	Section_ref::iterator p = this->section_reloc_map_.find(src_id);
	113	if (p == this->section_reloc_map_.end())
	114	this->section_reloc_map_[src_id].insert(dst_id);
	115	else
	116	p->second.insert(dst_id);
	117	}
	118
ef15dade ST	119	private:
	120
	121	Worklist_type work_list_;
	122	bool is_worklist_ready_;
	123	Section_ref section_reloc_map_;
	124	Sections_reachable referenced_list_;
f1ec9ded	125	Cident_section_map cident_sections_;
6d03d481 ST	126	};
	127
	128	// Data to pass between successive invocations of do_layout
	129	// in object.cc while garbage collecting. This data structure
	130	// is filled by using the data from Read_symbols_data.
	131
	132	struct Symbols_data
	133	{
	134	// Section headers.
	135	unsigned char* section_headers_data;
	136	// Section names.
	137	unsigned char* section_names_data;
	138	// Size of section name data in bytes.
	139	section_size_type section_names_size;
	140	// Symbol data.
	141	unsigned char* symbols_data;
	142	// Size of symbol data in bytes.
	143	section_size_type symbols_size;
	144	// Offset of external symbols within symbol data. This structure
	145	// sometimes contains only external symbols, in which case this will
	146	// be zero. Sometimes it contains all symbols.
	147	section_offset_type external_symbols_offset;
	148	// Symbol names.
	149	unsigned char* symbol_names_data;
	150	// Size of symbol name data in bytes.
	151	section_size_type symbol_names_size;
	152	};
	153
41cbeecc ST	154	// Relocations of type SHT_REL store the addend value in their bytes.
	155	// This function returns the size of the embedded addend which is
	156	// nothing but the size of the relocation.
	157
	158	template<typename Classify_reloc>
	159	inline unsigned int
	160	get_embedded_addend_size(int sh_type, int r_type, Relobj* obj)
	161	{
	162	if (sh_type != elfcpp::SHT_REL)
	163	return 0;
	164	Classify_reloc classify_reloc;
	165	return classify_reloc.get_size_for_reloc(r_type, obj);
	166	}
	167
ef15dade ST	168	// This function implements the generic part of reloc
	169	// processing to map a section to all the sections it
	170	// references through relocs. It is called only during
	171	// garbage collection (--gc-sections) and identical code
	172	// folding (--icf).
6d03d481 ST	173
6d03d481 ST	174	template<int size, bool big_endian, typename Target_type, int sh_type,
41cbeecc	175	typename Scan, typename Classify_reloc>
6d03d481 ST	176	inline void
6d03d481 ST	177	gc_process_relocs(
6d03d481 ST	178	Symbol_table* symtab,
6d03d481 ST	179	Layout*,
21bb3914	180	Target_type* target,
6fa2a40b	181	Sized_relobj_file<size, big_endian>* src_obj,
ef15dade	182	unsigned int src_indx,
6d03d481 ST	183	const unsigned char* prelocs,
	184	size_t reloc_count,
	185	Output_section*,
21bb3914	186	bool,
6d03d481 ST	187	size_t local_count,
	188	const unsigned char* plocal_syms)
	189	{
21bb3914	190	Scan scan;
6d03d481	191
6d03d481 ST	192	typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
	193	const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
	194	const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
	195
b487ad64 ST	196	Icf::Sections_reachable_info* secvec = NULL;
	197	Icf::Symbol_info* symvec = NULL;
	198	Icf::Addend_info* addendvec = NULL;
	199	Icf::Offset_info* offsetvec = NULL;
41cbeecc	200	Icf::Reloc_addend_size_info* reloc_addend_size_vec = NULL;
ef15dade	201	bool is_icf_tracked = false;
f1ec9ded	202	const char* cident_section_name = NULL;
ef15dade	203
21bb3914 ST	204	std::string src_section_name = (parameters->options().icf_enabled()
	205	? src_obj->section_name(src_indx)
	206	: "");
	207
	208	bool check_section_for_function_pointers = false;
	209
032ce4e9	210	if (parameters->options().icf_enabled()
21bb3914	211	&& is_section_foldable_candidate(src_section_name.c_str()))
ef15dade ST	212	{
	213	is_icf_tracked = true;
	214	Section_id src_id(src_obj, src_indx);
b487ad64 ST	215	Icf::Reloc_info* reloc_info =
	216	&symtab->icf()->reloc_info_list()[src_id];
	217	secvec = &reloc_info->section_info;
	218	symvec = &reloc_info->symbol_info;
	219	addendvec = &reloc_info->addend_info;
	220	offsetvec = &reloc_info->offset_info;
41cbeecc	221	reloc_addend_size_vec = &reloc_info->reloc_addend_size_info;
ef15dade ST	222	}
ef15dade ST	223
21bb3914 ST	224	check_section_for_function_pointers =
	225	symtab->icf()->check_section_for_function_pointers(src_section_name,
	226	target);
	227
6d03d481 ST	228	for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
	229	{
	230	Reltype reloc(prelocs);
	231	typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
	232	unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
21bb3914	233	unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
ef15dade ST	234	typename elfcpp::Elf_types<size>::Elf_Swxword addend =
ef15dade ST	235	Reloc_types<sh_type, size, big_endian>::get_reloc_addend_noerror(&reloc);
e81fea4d AM	236	Object* dst_obj;
e81fea4d AM	237	unsigned int dst_indx;
57420c20 AM	238	typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
57420c20 AM	239	Address dst_off;
ef15dade	240
6d03d481 ST	241	if (r_sym < local_count)
	242	{
	243	gold_assert(plocal_syms != NULL);
	244	typename elfcpp::Sym<size, big_endian> lsym(plocal_syms
	245	+ r_sym * sym_size);
57420c20	246	dst_indx = lsym.get_st_shndx();
6d03d481	247	bool is_ordinary;
57420c20	248	dst_indx = src_obj->adjust_sym_shndx(r_sym, dst_indx, &is_ordinary);
6d03d481	249	dst_obj = src_obj;
57420c20	250	dst_off = lsym.get_st_value() + addend;
e81fea4d	251
ef15dade ST	252	if (is_icf_tracked)
ef15dade ST	253	{
57420c20	254	Address symvalue = dst_off - addend;
ef38fd8a	255	if (is_ordinary)
ad3d8a2f	256	(*secvec).push_back(Section_id(dst_obj, dst_indx));
ef38fd8a ST	257	else
ef38fd8a ST	258	(*secvec).push_back(Section_id(NULL, 0));
ef15dade	259	(*symvec).push_back(NULL);
57420c20 AM	260	(*addendvec).push_back(std::make_pair(
	261	static_cast<long long>(symvalue),
	262	static_cast<long long>(addend)));
b487ad64 ST	263	uint64_t reloc_offset =
	264	convert_to_section_size_type(reloc.get_r_offset());
	265	(*offsetvec).push_back(reloc_offset);
41cbeecc ST	266	(*reloc_addend_size_vec).push_back(
	267	get_embedded_addend_size<Classify_reloc>(sh_type, r_type,
	268	src_obj));
ef15dade	269	}
21bb3914 ST	270
	271	// When doing safe folding, check to see if this relocation is that
	272	// of a function pointer being taken.
ef38fd8a ST	273	if (is_ordinary
ef38fd8a ST	274	&& check_section_for_function_pointers
21bb3914 ST	275	&& lsym.get_st_type() != elfcpp::STT_OBJECT
	276	&& scan.local_reloc_may_be_function_pointer(symtab, NULL, NULL,
	277	src_obj, src_indx,
	278	NULL, reloc, r_type,
	279	lsym))
	280	symtab->icf()->set_section_has_function_pointers(
	281	src_obj, lsym.get_st_shndx());
	282
57420c20	283	if (!is_ordinary \|\| dst_indx == src_indx)
ef15dade	284	continue;
6d03d481 ST	285	}
	286	else
	287	{
ef15dade	288	Symbol* gsym = src_obj->global_symbol(r_sym);
6d03d481 ST	289	gold_assert(gsym != NULL);
	290	if (gsym->is_forwarder())
	291	gsym = symtab->resolve_forwards(gsym);
ef38fd8a ST	292
	293	dst_obj = NULL;
	294	dst_indx = 0;
	295	bool is_ordinary = false;
	296	if (gsym->source() == Symbol::FROM_OBJECT)
	297	{
	298	dst_obj = gsym->object();
	299	dst_indx = gsym->shndx(&is_ordinary);
	300	}
57420c20 AM	301	dst_off = static_cast<const Sized_symbol<size>*>(gsym)->value();
57420c20 AM	302	dst_off += addend;
21bb3914 ST	303
	304	// When doing safe folding, check to see if this relocation is that
	305	// of a function pointer being taken.
ef38fd8a ST	306	if (gsym->source() == Symbol::FROM_OBJECT
ef38fd8a ST	307	&& check_section_for_function_pointers
21bb3914 ST	308	&& gsym->type() != elfcpp::STT_OBJECT
	309	&& (!is_ordinary
	310	\|\| scan.global_reloc_may_be_function_pointer(
	311	symtab, NULL, NULL, src_obj, src_indx, NULL, reloc,
	312	r_type, gsym)))
	313	symtab->icf()->set_section_has_function_pointers(dst_obj, dst_indx);
	314
f1ec9ded ST	315	// If the symbol name matches '__start_XXX' then the section with
	316	// the C identifier like name 'XXX' should not be garbage collected.
	317	// A similar treatment to symbols with the name '__stop_XXX'.
	318	if (is_prefix_of(cident_section_start_prefix, gsym->name()))
	319	{
	320	cident_section_name = (gsym->name()
	321	+ strlen(cident_section_start_prefix));
	322	}
	323	else if (is_prefix_of(cident_section_stop_prefix, gsym->name()))
	324	{
	325	cident_section_name = (gsym->name()
	326	+ strlen(cident_section_stop_prefix));
	327	}
ef15dade ST	328	if (is_icf_tracked)
ef15dade ST	329	{
57420c20	330	Address symvalue = dst_off - addend;
ef38fd8a	331	if (is_ordinary && gsym->source() == Symbol::FROM_OBJECT)
ad3d8a2f	332	(*secvec).push_back(Section_id(dst_obj, dst_indx));
ef38fd8a ST	333	else
ef38fd8a ST	334	(*secvec).push_back(Section_id(NULL, 0));
ef15dade	335	(*symvec).push_back(gsym);
57420c20 AM	336	(*addendvec).push_back(std::make_pair(
	337	static_cast<long long>(symvalue),
	338	static_cast<long long>(addend)));
b487ad64 ST	339	uint64_t reloc_offset =
	340	convert_to_section_size_type(reloc.get_r_offset());
	341	(*offsetvec).push_back(reloc_offset);
41cbeecc ST	342	(*reloc_addend_size_vec).push_back(
	343	get_embedded_addend_size<Classify_reloc>(sh_type, r_type,
	344	src_obj));
21bb3914	345	}
ef38fd8a ST	346
	347	if (gsym->source() != Symbol::FROM_OBJECT)
	348	continue;
	349	if (!is_ordinary)
	350	continue;
6d03d481	351	}
ef15dade	352	if (parameters->options().gc_sections())
6d03d481	353	{
99e5bff2	354	symtab->gc()->add_reference(src_obj, src_indx, dst_obj, dst_indx);
e81fea4d AM	355	parameters->sized_target<size, big_endian>()
	356	->gc_add_reference(symtab, src_obj, src_indx,
	357	dst_obj, dst_indx, dst_off);
f1ec9ded ST	358	if (cident_section_name != NULL)
	359	{
	360	Garbage_collection::Cident_section_map::iterator ele =
	361	symtab->gc()->cident_sections()->find(std::string(cident_section_name));
	362	if (ele == symtab->gc()->cident_sections()->end())
	363	continue;
99e5bff2	364	Section_id src_id(src_obj, src_indx);
f1ec9ded ST	365	Garbage_collection::Sections_reachable&
	366	v(symtab->gc()->section_reloc_map()[src_id]);
	367	Garbage_collection::Sections_reachable& cident_secn(ele->second);
	368	for (Garbage_collection::Sections_reachable::iterator it_v
	369	= cident_secn.begin();
	370	it_v != cident_secn.end();
	371	++it_v)
	372	{
	373	v.insert(*it_v);
	374	}
	375	}
6d03d481 ST	376	}
	377	}
	378	return;
	379	}
	380
	381	} // End of namespace gold.
	382
	383	#endif