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binutils-gdb/gold/dynobj.cc

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// dynobj.cc -- dynamic object support for gold
// Copyright (C) 2006-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@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.
#include "gold.h"
#include <vector>
#include <cstring>
#include "elfcpp.h"
#include "parameters.h"
#include "script.h"
#include "symtab.h"
#include "dynobj.h"
namespace gold
{
// Class Dynobj.
// Sets up the default soname_ to use, in the (rare) cases we never
// see a DT_SONAME entry.
Dynobj::Dynobj(const std::string& name, Input_file* input_file, off_t offset)
: Object(name, input_file, true, offset),
needed_(),
unknown_needed_(UNKNOWN_NEEDED_UNSET)
{
// This will be overridden by a DT_SONAME entry, hopefully. But if
// we never see a DT_SONAME entry, our rule is to use the dynamic
// object's filename. The only exception is when the dynamic object
// is part of an archive (so the filename is the archive's
// filename). In that case, we use just the dynobj's name-in-archive.
if (input_file == NULL)
this->soname_ = name;
else
{
this->soname_ = input_file->found_name();
if (this->offset() != 0)
{
std::string::size_type open_paren = this->name().find('(');
std::string::size_type close_paren = this->name().find(')');
if (open_paren != std::string::npos
&& close_paren != std::string::npos)
{
// It's an archive, and name() is of the form 'foo.a(bar.so)'.
open_paren += 1;
this->soname_ = this->name().substr(open_paren,
close_paren - open_paren);
}
}
}
}
// Class Sized_dynobj.
template<int size, bool big_endian>
Sized_dynobj<size, big_endian>::Sized_dynobj(
const std::string& name,
Input_file* input_file,
off_t offset,
const elfcpp::Ehdr<size, big_endian>& ehdr)
: Dynobj(name, input_file, offset),
elf_file_(this, ehdr),
dynsym_shndx_(-1U),
symbols_(NULL),
defined_count_(0)
{
}
// Set up the object.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::setup()
{
const unsigned int shnum = this->elf_file_.shnum();
this->set_shnum(shnum);
}
// Find the SHT_DYNSYM section and the various version sections, and
// the dynamic section, given the section headers.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::find_dynsym_sections(
const unsigned char* pshdrs,
unsigned int* pversym_shndx,
unsigned int* pverdef_shndx,
unsigned int* pverneed_shndx,
unsigned int* pdynamic_shndx)
{
*pversym_shndx = -1U;
*pverdef_shndx = -1U;
*pverneed_shndx = -1U;
*pdynamic_shndx = -1U;
unsigned int symtab_shndx = 0;
unsigned int xindex_shndx = 0;
unsigned int xindex_link = 0;
const unsigned int shnum = this->shnum();
const unsigned char* p = pshdrs;
for (unsigned int i = 0; i < shnum; ++i, p += This::shdr_size)
{
typename This::Shdr shdr(p);
unsigned int* pi;
switch (shdr.get_sh_type())
{
case elfcpp::SHT_DYNSYM:
this->dynsym_shndx_ = i;
if (xindex_shndx > 0 && xindex_link == i)
{
Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
xindex->read_symtab_xindex<size, big_endian>(this, xindex_shndx,
pshdrs);
this->set_xindex(xindex);
}
pi = NULL;
break;
case elfcpp::SHT_SYMTAB:
symtab_shndx = i;
pi = NULL;
break;
case elfcpp::SHT_GNU_versym:
pi = pversym_shndx;
break;
case elfcpp::SHT_GNU_verdef:
pi = pverdef_shndx;
break;
case elfcpp::SHT_GNU_verneed:
pi = pverneed_shndx;
break;
case elfcpp::SHT_DYNAMIC:
pi = pdynamic_shndx;
break;
case elfcpp::SHT_SYMTAB_SHNDX:
xindex_shndx = i;
xindex_link = this->adjust_shndx(shdr.get_sh_link());
if (xindex_link == this->dynsym_shndx_)
{
Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
xindex->read_symtab_xindex<size, big_endian>(this, xindex_shndx,
pshdrs);
this->set_xindex(xindex);
}
pi = NULL;
break;
default:
pi = NULL;
break;
}
if (pi == NULL)
continue;
if (*pi != -1U)
this->error(_("unexpected duplicate type %u section: %u, %u"),
shdr.get_sh_type(), *pi, i);
*pi = i;
}
// If there is no dynamic symbol table, use the normal symbol table.
// On some SVR4 systems, a shared library is stored in an archive.
// The version stored in the archive only has a normal symbol table.
// It has an SONAME entry which points to another copy in the file
// system which has a dynamic symbol table as usual. This is way of
// addressing the issues which glibc addresses using GROUP with
// libc_nonshared.a.
if (this->dynsym_shndx_ == -1U && symtab_shndx != 0)
{
this->dynsym_shndx_ = symtab_shndx;
if (xindex_shndx > 0 && xindex_link == symtab_shndx)
{
Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
xindex->read_symtab_xindex<size, big_endian>(this, xindex_shndx,
pshdrs);
this->set_xindex(xindex);
}
}
}
// Read the contents of section SHNDX. PSHDRS points to the section
// headers. TYPE is the expected section type. LINK is the expected
// section link. Store the data in *VIEW and *VIEW_SIZE. The
// section's sh_info field is stored in *VIEW_INFO.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::read_dynsym_section(
const unsigned char* pshdrs,
unsigned int shndx,
elfcpp::SHT type,
unsigned int link,
File_view** view,
section_size_type* view_size,
unsigned int* view_info)
{
if (shndx == -1U)
{
*view = NULL;
*view_size = 0;
*view_info = 0;
return;
}
typename This::Shdr shdr(pshdrs + shndx * This::shdr_size);
gold_assert(shdr.get_sh_type() == type);
if (this->adjust_shndx(shdr.get_sh_link()) != link)
this->error(_("unexpected link in section %u header: %u != %u"),
shndx, this->adjust_shndx(shdr.get_sh_link()), link);
*view = this->get_lasting_view(shdr.get_sh_offset(), shdr.get_sh_size(),
true, false);
*view_size = convert_to_section_size_type(shdr.get_sh_size());
*view_info = shdr.get_sh_info();
}
// Read the dynamic tags. Set the soname field if this shared object
// has a DT_SONAME tag. Record the DT_NEEDED tags. PSHDRS points to
// the section headers. DYNAMIC_SHNDX is the section index of the
// SHT_DYNAMIC section. STRTAB_SHNDX, STRTAB, and STRTAB_SIZE are the
// section index and contents of a string table which may be the one
// associated with the SHT_DYNAMIC section.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::read_dynamic(const unsigned char* pshdrs,
unsigned int dynamic_shndx,
unsigned int strtab_shndx,
const unsigned char* strtabu,
off_t strtab_size)
{
typename This::Shdr dynamicshdr(pshdrs + dynamic_shndx * This::shdr_size);
gold_assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC);
const off_t dynamic_size = dynamicshdr.get_sh_size();
const unsigned char* pdynamic = this->get_view(dynamicshdr.get_sh_offset(),
dynamic_size, true, false);
const unsigned int link = this->adjust_shndx(dynamicshdr.get_sh_link());
if (link != strtab_shndx)
{
if (link >= this->shnum())
{
this->error(_("DYNAMIC section %u link out of range: %u"),
dynamic_shndx, link);
return;
}
typename This::Shdr strtabshdr(pshdrs + link * This::shdr_size);
if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
{
this->error(_("DYNAMIC section %u link %u is not a strtab"),
dynamic_shndx, link);
return;
}
strtab_size = strtabshdr.get_sh_size();
strtabu = this->get_view(strtabshdr.get_sh_offset(), strtab_size, false,
false);
}
const char* const strtab = reinterpret_cast<const char*>(strtabu);
for (const unsigned char* p = pdynamic;
p < pdynamic + dynamic_size;
p += This::dyn_size)
{
typename This::Dyn dyn(p);
switch (dyn.get_d_tag())
{
case elfcpp::DT_NULL:
// We should always see DT_NULL at the end of the dynamic
// tags.
return;
case elfcpp::DT_SONAME:
{
off_t val = dyn.get_d_val();
if (val >= strtab_size)
this->error(_("DT_SONAME value out of range: %lld >= %lld"),
static_cast<long long>(val),
static_cast<long long>(strtab_size));
else
this->set_soname_string(strtab + val);
}
break;
case elfcpp::DT_NEEDED:
{
off_t val = dyn.get_d_val();
if (val >= strtab_size)
this->error(_("DT_NEEDED value out of range: %lld >= %lld"),
static_cast<long long>(val),
static_cast<long long>(strtab_size));
else
this->add_needed(strtab + val);
}
break;
default:
break;
}
}
this->error(_("missing DT_NULL in dynamic segment"));
}
// Read the symbols and sections from a dynamic object. We read the
// dynamic symbols, not the normal symbols.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
{
this->base_read_symbols(sd);
}
// Read the symbols and sections from a dynamic object. We read the
// dynamic symbols, not the normal symbols. This is common code for
// all target-specific overrides of do_read_symbols().
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::base_read_symbols(Read_symbols_data* sd)
{
this->read_section_data(&this->elf_file_, sd);
const unsigned char* const pshdrs = sd->section_headers->data();
unsigned int versym_shndx;
unsigned int verdef_shndx;
unsigned int verneed_shndx;
unsigned int dynamic_shndx;
this->find_dynsym_sections(pshdrs, &versym_shndx, &verdef_shndx,
&verneed_shndx, &dynamic_shndx);
unsigned int strtab_shndx = -1U;
sd->symbols = NULL;
sd->symbols_size = 0;
sd->external_symbols_offset = 0;
sd->symbol_names = NULL;
sd->symbol_names_size = 0;
sd->versym = NULL;
sd->versym_size = 0;
sd->verdef = NULL;
sd->verdef_size = 0;
sd->verdef_info = 0;
sd->verneed = NULL;
sd->verneed_size = 0;
sd->verneed_info = 0;
const unsigned char* namesu = sd->section_names->data();
const char* names = reinterpret_cast<const char*>(namesu);
if (memmem(names, sd->section_names_size, ".zdebug_", 8) != NULL)
{
Compressed_section_map* compressed_sections =
build_compressed_section_map<size, big_endian>(
pshdrs, this->shnum(), names, sd->section_names_size, this, true);
if (compressed_sections != NULL)
this->set_compressed_sections(compressed_sections);
}
if (this->dynsym_shndx_ != -1U)
{
// Get the dynamic symbols.
typename This::Shdr dynsymshdr(pshdrs
+ this->dynsym_shndx_ * This::shdr_size);
sd->symbols = this->get_lasting_view(dynsymshdr.get_sh_offset(),
dynsymshdr.get_sh_size(), true,
false);
sd->symbols_size =
convert_to_section_size_type(dynsymshdr.get_sh_size());
// Get the symbol names.
strtab_shndx = this->adjust_shndx(dynsymshdr.get_sh_link());
if (strtab_shndx >= this->shnum())
{
this->error(_("invalid dynamic symbol table name index: %u"),
strtab_shndx);
return;
}
typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
{
this->error(_("dynamic symbol table name section "
"has wrong type: %u"),
static_cast<unsigned int>(strtabshdr.get_sh_type()));
return;
}
sd->symbol_names = this->get_lasting_view(strtabshdr.get_sh_offset(),
strtabshdr.get_sh_size(),
false, false);
sd->symbol_names_size =
convert_to_section_size_type(strtabshdr.get_sh_size());
// Get the version information.
unsigned int dummy;
this->read_dynsym_section(pshdrs, versym_shndx, elfcpp::SHT_GNU_versym,
this->dynsym_shndx_,
&sd->versym, &sd->versym_size, &dummy);
// We require that the version definition and need section link
// to the same string table as the dynamic symbol table. This
// is not a technical requirement, but it always happens in
// practice. We could change this if necessary.
this->read_dynsym_section(pshdrs, verdef_shndx, elfcpp::SHT_GNU_verdef,
strtab_shndx, &sd->verdef, &sd->verdef_size,
&sd->verdef_info);
this->read_dynsym_section(pshdrs, verneed_shndx, elfcpp::SHT_GNU_verneed,
strtab_shndx, &sd->verneed, &sd->verneed_size,
&sd->verneed_info);
}
// Read the SHT_DYNAMIC section to find whether this shared object
// has a DT_SONAME tag and to record any DT_NEEDED tags. This
// doesn't really have anything to do with reading the symbols, but
// this is a convenient place to do it.
if (dynamic_shndx != -1U)
this->read_dynamic(pshdrs, dynamic_shndx, strtab_shndx,
(sd->symbol_names == NULL
? NULL
: sd->symbol_names->data()),
sd->symbol_names_size);
}
// Return the Xindex structure to use for object with lots of
// sections.
template<int size, bool big_endian>
Xindex*
Sized_dynobj<size, big_endian>::do_initialize_xindex()
{
gold_assert(this->dynsym_shndx_ != -1U);
Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
xindex->initialize_symtab_xindex<size, big_endian>(this, this->dynsym_shndx_);
return xindex;
}
// Lay out the input sections for a dynamic object. We don't want to
// include sections from a dynamic object, so all that we actually do
// here is check for .gnu.warning and .note.GNU-split-stack sections.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::do_layout(Symbol_table* symtab,
Layout*,
Read_symbols_data* sd)
{
const unsigned int shnum = this->shnum();
if (shnum == 0)
return;
// Get the section headers.
const unsigned char* pshdrs = sd->section_headers->data();
// Get the section names.
const unsigned char* pnamesu = sd->section_names->data();
const char* pnames = reinterpret_cast<const char*>(pnamesu);
// Skip the first, dummy, section.
pshdrs += This::shdr_size;
for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
{
typename This::Shdr shdr(pshdrs);
if (shdr.get_sh_name() >= sd->section_names_size)
{
this->error(_("bad section name offset for section %u: %lu"),
i, static_cast<unsigned long>(shdr.get_sh_name()));
return;
}
const char* name = pnames + shdr.get_sh_name();
this->handle_gnu_warning_section(name, i, symtab);
this->handle_split_stack_section(name);
}
delete sd->section_headers;
sd->section_headers = NULL;
delete sd->section_names;
sd->section_names = NULL;
}
// Add an entry to the vector mapping version numbers to version
// strings.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::set_version_map(
Version_map* version_map,
unsigned int ndx,
const char* name) const
{
if (ndx >= version_map->size())
version_map->resize(ndx + 1);
if ((*version_map)[ndx] != NULL)
this->error(_("duplicate definition for version %u"), ndx);
(*version_map)[ndx] = name;
}
// Add mappings for the version definitions to VERSION_MAP.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::make_verdef_map(
Read_symbols_data* sd,
Version_map* version_map) const
{
if (sd->verdef == NULL)
return;
const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
section_size_type names_size = sd->symbol_names_size;
const unsigned char* pverdef = sd->verdef->data();
section_size_type verdef_size = sd->verdef_size;
const unsigned int count = sd->verdef_info;
const unsigned char* p = pverdef;
for (unsigned int i = 0; i < count; ++i)
{
elfcpp::Verdef<size, big_endian> verdef(p);
if (verdef.get_vd_version() != elfcpp::VER_DEF_CURRENT)
{
this->error(_("unexpected verdef version %u"),
verdef.get_vd_version());
return;
}
const section_size_type vd_ndx = verdef.get_vd_ndx();
// The GNU linker clears the VERSYM_HIDDEN bit. I'm not
// sure why.
// The first Verdaux holds the name of this version. Subsequent
// ones are versions that this one depends upon, which we don't
// care about here.
const section_size_type vd_cnt = verdef.get_vd_cnt();
if (vd_cnt < 1)
{
this->error(_("verdef vd_cnt field too small: %u"),
static_cast<unsigned int>(vd_cnt));
return;
}
const section_size_type vd_aux = verdef.get_vd_aux();
if ((p - pverdef) + vd_aux >= verdef_size)
{
this->error(_("verdef vd_aux field out of range: %u"),
static_cast<unsigned int>(vd_aux));
return;
}
const unsigned char* pvda = p + vd_aux;
elfcpp::Verdaux<size, big_endian> verdaux(pvda);
const section_size_type vda_name = verdaux.get_vda_name();
if (vda_name >= names_size)
{
this->error(_("verdaux vda_name field out of range: %u"),
static_cast<unsigned int>(vda_name));
return;
}
this->set_version_map(version_map, vd_ndx, names + vda_name);
const section_size_type vd_next = verdef.get_vd_next();
if ((p - pverdef) + vd_next >= verdef_size)
{
this->error(_("verdef vd_next field out of range: %u"),
static_cast<unsigned int>(vd_next));
return;
}
p += vd_next;
}
}
// Add mappings for the required versions to VERSION_MAP.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::make_verneed_map(
Read_symbols_data* sd,
Version_map* version_map) const
{
if (sd->verneed == NULL)
return;
const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
section_size_type names_size = sd->symbol_names_size;
const unsigned char* pverneed = sd->verneed->data();
const section_size_type verneed_size = sd->verneed_size;
const unsigned int count = sd->verneed_info;
const unsigned char* p = pverneed;
for (unsigned int i = 0; i < count; ++i)
{
elfcpp::Verneed<size, big_endian> verneed(p);
if (verneed.get_vn_version() != elfcpp::VER_NEED_CURRENT)
{
this->error(_("unexpected verneed version %u"),
verneed.get_vn_version());
return;
}
const section_size_type vn_aux = verneed.get_vn_aux();
if ((p - pverneed) + vn_aux >= verneed_size)
{
this->error(_("verneed vn_aux field out of range: %u"),
static_cast<unsigned int>(vn_aux));
return;
}
const unsigned int vn_cnt = verneed.get_vn_cnt();
const unsigned char* pvna = p + vn_aux;
for (unsigned int j = 0; j < vn_cnt; ++j)
{
elfcpp::Vernaux<size, big_endian> vernaux(pvna);
const unsigned int vna_name = vernaux.get_vna_name();
if (vna_name >= names_size)
{
this->error(_("vernaux vna_name field out of range: %u"),
static_cast<unsigned int>(vna_name));
return;
}
this->set_version_map(version_map, vernaux.get_vna_other(),
names + vna_name);
const section_size_type vna_next = vernaux.get_vna_next();
if ((pvna - pverneed) + vna_next >= verneed_size)
{
this->error(_("verneed vna_next field out of range: %u"),
static_cast<unsigned int>(vna_next));
return;
}
pvna += vna_next;
}
const section_size_type vn_next = verneed.get_vn_next();
if ((p - pverneed) + vn_next >= verneed_size)
{
this->error(_("verneed vn_next field out of range: %u"),
static_cast<unsigned int>(vn_next));
return;
}
p += vn_next;
}
}
// Create a vector mapping version numbers to version strings.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::make_version_map(
Read_symbols_data* sd,
Version_map* version_map) const
{
if (sd->verdef == NULL && sd->verneed == NULL)
return;
// A guess at the maximum version number we will see. If this is
// wrong we will be less efficient but still correct.
version_map->reserve(sd->verdef_info + sd->verneed_info * 10);
this->make_verdef_map(sd, version_map);
this->make_verneed_map(sd, version_map);
}
// Add the dynamic symbols to the symbol table.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
Read_symbols_data* sd,
Layout*)
{
if (sd->symbols == NULL)
{
gold_assert(sd->symbol_names == NULL);
gold_assert(sd->versym == NULL && sd->verdef == NULL
&& sd->verneed == NULL);
return;
}
const int sym_size = This::sym_size;
const size_t symcount = sd->symbols_size / sym_size;
gold_assert(sd->external_symbols_offset == 0);
if (symcount * sym_size != sd->symbols_size)
{
this->error(_("size of dynamic symbols is not multiple of symbol size"));
return;
}
Version_map version_map;
this->make_version_map(sd, &version_map);
// If printing symbol counts or a cross reference table or
// preparing for an incremental link, we want to track symbols.
if (parameters->options().user_set_print_symbol_counts()
|| parameters->options().cref()
|| parameters->incremental())
{
this->symbols_ = new Symbols();
this->symbols_->resize(symcount);
}
const char* sym_names =
reinterpret_cast<const char*>(sd->symbol_names->data());
symtab->add_from_dynobj(this, sd->symbols->data(), symcount,
sym_names, sd->symbol_names_size,
(sd->versym == NULL
? NULL
: sd->versym->data()),
sd->versym_size,
&version_map,
this->symbols_,
&this->defined_count_);
delete sd->symbols;
sd->symbols = NULL;
delete sd->symbol_names;
sd->symbol_names = NULL;
if (sd->versym != NULL)
{
delete sd->versym;
sd->versym = NULL;
}
if (sd->verdef != NULL)
{
delete sd->verdef;
sd->verdef = NULL;
}
if (sd->verneed != NULL)
{
delete sd->verneed;
sd->verneed = NULL;
}
// This is normally the last time we will read any data from this
// file.
this->clear_view_cache_marks();
}
template<int size, bool big_endian>
Archive::Should_include
Sized_dynobj<size, big_endian>::do_should_include_member(Symbol_table*,
Layout*,
Read_symbols_data*,
std::string*)
{
return Archive::SHOULD_INCLUDE_YES;
}
// Iterate over global symbols, calling a visitor class V for each.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::do_for_all_global_symbols(
Read_symbols_data* sd,
Library_base::Symbol_visitor_base* v)
{
const char* sym_names =
reinterpret_cast<const char*>(sd->symbol_names->data());
const unsigned char* syms =
sd->symbols->data() + sd->external_symbols_offset;
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
/ sym_size);
const unsigned char* p = syms;
for (size_t i = 0; i < symcount; ++i, p += sym_size)
{
elfcpp::Sym<size, big_endian> sym(p);
if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
&& sym.get_st_bind() != elfcpp::STB_LOCAL)
v->visit(sym_names + sym.get_st_name());
}
}
// Iterate over local symbols, calling a visitor class V for each GOT offset
// associated with a local symbol.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::do_for_all_local_got_entries(
Got_offset_list::Visitor*) const
{
}
// Get symbol counts.
template<int size, bool big_endian>
void
Sized_dynobj<size, big_endian>::do_get_global_symbol_counts(
const Symbol_table*,
size_t* defined,
size_t* used) const
{
*defined = this->defined_count_;
size_t count = 0;
for (typename Symbols::const_iterator p = this->symbols_->begin();
p != this->symbols_->end();
++p)
if (*p != NULL
&& (*p)->source() == Symbol::FROM_OBJECT
&& (*p)->object() == this
&& (*p)->is_defined()
&& (*p)->has_dynsym_index())
++count;
*used = count;
}
// Given a vector of hash codes, compute the number of hash buckets to
// use.
unsigned int
Dynobj::compute_bucket_count(const std::vector<uint32_t>& hashcodes,
bool for_gnu_hash_table)
{
// FIXME: Implement optional hash table optimization.
// Array used to determine the number of hash table buckets to use
// based on the number of symbols there are. If there are fewer
// than 3 symbols we use 1 bucket, fewer than 17 symbols we use 3
// buckets, fewer than 37 we use 17 buckets, and so forth. We never
// use more than 262147 buckets. This is straight from the old GNU
// linker.
static const unsigned int buckets[] =
{
1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
16411, 32771, 65537, 131101, 262147
};
const int buckets_count = sizeof buckets / sizeof buckets[0];
unsigned int symcount = hashcodes.size();
unsigned int ret = 1;
const double full_fraction
= 1.0 - parameters->options().hash_bucket_empty_fraction();
for (int i = 0; i < buckets_count; ++i)
{
if (symcount < buckets[i] * full_fraction)
break;
ret = buckets[i];
}
if (for_gnu_hash_table && ret < 2)
ret = 2;
return ret;
}
// The standard ELF hash function. This hash function must not
// change, as the dynamic linker uses it also.
uint32_t
Dynobj::elf_hash(const char* name)
{
const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
uint32_t h = 0;
unsigned char c;
while ((c = *nameu++) != '\0')
{
h = (h << 4) + c;
uint32_t g = h & 0xf0000000;
if (g != 0)
{
h ^= g >> 24;
// The ELF ABI says h &= ~g, but using xor is equivalent in
// this case (since g was set from h) and may save one
// instruction.
h ^= g;
}
}
return h;
}
// Create a standard ELF hash table, setting *PPHASH and *PHASHLEN.
// DYNSYMS is a vector with all the global dynamic symbols.
// LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
// symbol table.
void
Dynobj::create_elf_hash_table(const std::vector<Symbol*>& dynsyms,
unsigned int local_dynsym_count,
unsigned char** pphash,
unsigned int* phashlen)
{
unsigned int dynsym_count = dynsyms.size();
// Get the hash values for all the symbols.
std::vector<uint32_t> dynsym_hashvals(dynsym_count);
for (unsigned int i = 0; i < dynsym_count; ++i)
dynsym_hashvals[i] = Dynobj::elf_hash(dynsyms[i]->name());
const unsigned int bucketcount =
Dynobj::compute_bucket_count(dynsym_hashvals, false);
std::vector<uint32_t> bucket(bucketcount);
std::vector<uint32_t> chain(local_dynsym_count + dynsym_count);
for (unsigned int i = 0; i < dynsym_count; ++i)
{
unsigned int dynsym_index = dynsyms[i]->dynsym_index();
unsigned int bucketpos = dynsym_hashvals[i] % bucketcount;
chain[dynsym_index] = bucket[bucketpos];
bucket[bucketpos] = dynsym_index;
}
int size = parameters->target().hash_entry_size();
unsigned int hashlen = ((2
+ bucketcount
+ local_dynsym_count
+ dynsym_count)
* size / 8);
unsigned char* phash = new unsigned char[hashlen];
bool big_endian = parameters->target().is_big_endian();
if (size == 32)
{
if (big_endian)
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
Dynobj::sized_create_elf_hash_table<32, true>(bucket, chain, phash,
hashlen);
#else
gold_unreachable();
#endif
}
else
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
Dynobj::sized_create_elf_hash_table<32, false>(bucket, chain, phash,
hashlen);
#else
gold_unreachable();
#endif
}
}
else if (size == 64)
{
if (big_endian)
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
Dynobj::sized_create_elf_hash_table<64, true>(bucket, chain, phash,
hashlen);
#else
gold_unreachable();
#endif
}
else
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
Dynobj::sized_create_elf_hash_table<64, false>(bucket, chain, phash,
hashlen);
#else
gold_unreachable();
#endif
}
}
else
gold_unreachable();
*pphash = phash;
*phashlen = hashlen;
}
// Fill in an ELF hash table.
template<int size, bool big_endian>
void
Dynobj::sized_create_elf_hash_table(const std::vector<uint32_t>& bucket,
const std::vector<uint32_t>& chain,
unsigned char* phash,
unsigned int hashlen)
{
unsigned char* p = phash;
const unsigned int bucketcount = bucket.size();
const unsigned int chaincount = chain.size();
elfcpp::Swap<size, big_endian>::writeval(p, bucketcount);
p += size / 8;
elfcpp::Swap<size, big_endian>::writeval(p, chaincount);
p += size / 8;
for (unsigned int i = 0; i < bucketcount; ++i)
{
elfcpp::Swap<size, big_endian>::writeval(p, bucket[i]);
p += size / 8;
}
for (unsigned int i = 0; i < chaincount; ++i)
{
elfcpp::Swap<size, big_endian>::writeval(p, chain[i]);
p += size / 8;
}
gold_assert(static_cast<unsigned int>(p - phash) == hashlen);
}
// The hash function used for the GNU hash table. This hash function
// must not change, as the dynamic linker uses it also.
uint32_t
Dynobj::gnu_hash(const char* name)
{
const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
uint32_t h = 5381;
unsigned char c;
while ((c = *nameu++) != '\0')
h = (h << 5) + h + c;
return h;
}
// Create a GNU hash table, setting *PPHASH and *PHASHLEN. GNU hash
// tables are an extension to ELF which are recognized by the GNU
// dynamic linker. They are referenced using dynamic tag DT_GNU_HASH.
// TARGET is the target. DYNSYMS is a vector with all the global
// symbols which will be going into the dynamic symbol table.
// LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
// symbol table.
void
Dynobj::create_gnu_hash_table(const std::vector<Symbol*>& dynsyms,
unsigned int local_dynsym_count,
unsigned char** pphash,
unsigned int* phashlen)
{
const unsigned int count = dynsyms.size();
// Sort the dynamic symbols into two vectors. Symbols which we do
// not want to put into the hash table we store into
// UNHASHED_DYNSYMS. Symbols which we do want to store we put into
// HASHED_DYNSYMS. DYNSYM_HASHVALS is parallel to HASHED_DYNSYMS,
// and records the hash codes.
std::vector<Symbol*> unhashed_dynsyms;
unhashed_dynsyms.reserve(count);
std::vector<Symbol*> hashed_dynsyms;
hashed_dynsyms.reserve(count);
std::vector<uint32_t> dynsym_hashvals;
dynsym_hashvals.reserve(count);
for (unsigned int i = 0; i < count; ++i)
{
Symbol* sym = dynsyms[i];
if (!sym->needs_dynsym_value()
&& (sym->is_undefined()
|| sym->is_from_dynobj()
|| sym->is_forced_local()))
unhashed_dynsyms.push_back(sym);
else
{
hashed_dynsyms.push_back(sym);
dynsym_hashvals.push_back(Dynobj::gnu_hash(sym->name()));
}
}
// Put the unhashed symbols at the start of the global portion of
// the dynamic symbol table.
const unsigned int unhashed_count = unhashed_dynsyms.size();
unsigned int unhashed_dynsym_index = local_dynsym_count;
for (unsigned int i = 0; i < unhashed_count; ++i)
{
unhashed_dynsyms[i]->set_dynsym_index(unhashed_dynsym_index);
++unhashed_dynsym_index;
}
// For the actual data generation we call out to a templatized
// function.
int size = parameters->target().get_size();
bool big_endian = parameters->target().is_big_endian();
if (size == 32)
{
if (big_endian)
{
#ifdef HAVE_TARGET_32_BIG
Dynobj::sized_create_gnu_hash_table<32, true>(hashed_dynsyms,
dynsym_hashvals,
unhashed_dynsym_index,
pphash,
phashlen);
#else
gold_unreachable();
#endif
}
else
{
#ifdef HAVE_TARGET_32_LITTLE
Dynobj::sized_create_gnu_hash_table<32, false>(hashed_dynsyms,
dynsym_hashvals,
unhashed_dynsym_index,
pphash,
phashlen);
#else
gold_unreachable();
#endif
}
}
else if (size == 64)
{
if (big_endian)
{
#ifdef HAVE_TARGET_64_BIG
Dynobj::sized_create_gnu_hash_table<64, true>(hashed_dynsyms,
dynsym_hashvals,
unhashed_dynsym_index,
pphash,
phashlen);
#else
gold_unreachable();
#endif
}
else
{
#ifdef HAVE_TARGET_64_LITTLE
Dynobj::sized_create_gnu_hash_table<64, false>(hashed_dynsyms,
dynsym_hashvals,
unhashed_dynsym_index,
pphash,
phashlen);
#else
gold_unreachable();
#endif
}
}
else
gold_unreachable();
}
// Create the actual data for a GNU hash table. This is just a copy
// of the code from the old GNU linker.
template<int size, bool big_endian>
void
Dynobj::sized_create_gnu_hash_table(
const std::vector<Symbol*>& hashed_dynsyms,
const std::vector<uint32_t>& dynsym_hashvals,
unsigned int unhashed_dynsym_count,
unsigned char** pphash,
unsigned int* phashlen)
{
if (hashed_dynsyms.empty())
{
// Special case for the empty hash table.
unsigned int hashlen = 5 * 4 + size / 8;
unsigned char* phash = new unsigned char[hashlen];
// One empty bucket.
elfcpp::Swap<32, big_endian>::writeval(phash, 1);
// Symbol index above unhashed symbols.
elfcpp::Swap<32, big_endian>::writeval(phash + 4, unhashed_dynsym_count);
// One word for bitmask.
elfcpp::Swap<32, big_endian>::writeval(phash + 8, 1);
// Only bloom filter.
elfcpp::Swap<32, big_endian>::writeval(phash + 12, 0);
// No valid hashes.
elfcpp::Swap<size, big_endian>::writeval(phash + 16, 0);
// No hashes in only bucket.
elfcpp::Swap<32, big_endian>::writeval(phash + 16 + size / 8, 0);
*phashlen = hashlen;
*pphash = phash;
return;
}
const unsigned int bucketcount =
Dynobj::compute_bucket_count(dynsym_hashvals, true);
const unsigned int nsyms = hashed_dynsyms.size();
uint32_t maskbitslog2 = 1;
uint32_t x = nsyms >> 1;
while (x != 0)
{
++maskbitslog2;
x >>= 1;
}
if (maskbitslog2 < 3)
maskbitslog2 = 5;
else if (((1U << (maskbitslog2 - 2)) & nsyms) != 0)
maskbitslog2 += 3;
else
maskbitslog2 += 2;
uint32_t shift1;
if (size == 32)
shift1 = 5;
else
{
if (maskbitslog2 == 5)
maskbitslog2 = 6;
shift1 = 6;
}
uint32_t mask = (1U << shift1) - 1U;
uint32_t shift2 = maskbitslog2;
uint32_t maskbits = 1U << maskbitslog2;
uint32_t maskwords = 1U << (maskbitslog2 - shift1);
typedef typename elfcpp::Elf_types<size>::Elf_WXword Word;
std::vector<Word> bitmask(maskwords);
std::vector<uint32_t> counts(bucketcount);
std::vector<uint32_t> indx(bucketcount);
uint32_t symindx = unhashed_dynsym_count;
// Count the number of times each hash bucket is used.
for (unsigned int i = 0; i < nsyms; ++i)
++counts[dynsym_hashvals[i] % bucketcount];
unsigned int cnt = symindx;
for (unsigned int i = 0; i < bucketcount; ++i)
{
indx[i] = cnt;
cnt += counts[i];
}
unsigned int hashlen = (4 + bucketcount + nsyms) * 4;
hashlen += maskbits / 8;
unsigned char* phash = new unsigned char[hashlen];
elfcpp::Swap<32, big_endian>::writeval(phash, bucketcount);
elfcpp::Swap<32, big_endian>::writeval(phash + 4, symindx);
elfcpp::Swap<32, big_endian>::writeval(phash + 8, maskwords);
elfcpp::Swap<32, big_endian>::writeval(phash + 12, shift2);
unsigned char* p = phash + 16 + maskbits / 8;
for (unsigned int i = 0; i < bucketcount; ++i)
{
if (counts[i] == 0)
elfcpp::Swap<32, big_endian>::writeval(p, 0);
else
elfcpp::Swap<32, big_endian>::writeval(p, indx[i]);
p += 4;
}
for (unsigned int i = 0; i < nsyms; ++i)
{
Symbol* sym = hashed_dynsyms[i];
uint32_t hashval = dynsym_hashvals[i];
unsigned int bucket = hashval % bucketcount;
unsigned int val = ((hashval >> shift1)
& ((maskbits >> shift1) - 1));
bitmask[val] |= (static_cast<Word>(1U)) << (hashval & mask);
bitmask[val] |= (static_cast<Word>(1U)) << ((hashval >> shift2) & mask);
val = hashval & ~ 1U;
if (counts[bucket] == 1)
{
// Last element terminates the chain.
val |= 1;
}
elfcpp::Swap<32, big_endian>::writeval(p + (indx[bucket] - symindx) * 4,
val);
--counts[bucket];
sym->set_dynsym_index(indx[bucket]);
++indx[bucket];
}
p = phash + 16;
for (unsigned int i = 0; i < maskwords; ++i)
{
elfcpp::Swap<size, big_endian>::writeval(p, bitmask[i]);
p += size / 8;
}
*phashlen = hashlen;
*pphash = phash;
}
// Verdef methods.
// Write this definition to a buffer for the output section.
template<int size, bool big_endian>
unsigned char*
Verdef::write(const Stringpool* dynpool, bool is_last, unsigned char* pb) const
{
const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size;
const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size;
elfcpp::Verdef_write<size, big_endian> vd(pb);
vd.set_vd_version(elfcpp::VER_DEF_CURRENT);
vd.set_vd_flags((this->is_base_ ? elfcpp::VER_FLG_BASE : 0)
| (this->is_weak_ ? elfcpp::VER_FLG_WEAK : 0)
| (this->is_info_ ? elfcpp::VER_FLG_INFO : 0));
vd.set_vd_ndx(this->index());
vd.set_vd_cnt(1 + this->deps_.size());
vd.set_vd_hash(Dynobj::elf_hash(this->name()));
vd.set_vd_aux(verdef_size);
vd.set_vd_next(is_last
? 0
: verdef_size + (1 + this->deps_.size()) * verdaux_size);
pb += verdef_size;
elfcpp::Verdaux_write<size, big_endian> vda(pb);
vda.set_vda_name(dynpool->get_offset(this->name()));
vda.set_vda_next(this->deps_.empty() ? 0 : verdaux_size);
pb += verdaux_size;
Deps::const_iterator p;
unsigned int i;
for (p = this->deps_.begin(), i = 0;
p != this->deps_.end();
++p, ++i)
{
elfcpp::Verdaux_write<size, big_endian> vda(pb);
vda.set_vda_name(dynpool->get_offset(*p));
vda.set_vda_next(i + 1 >= this->deps_.size() ? 0 : verdaux_size);
pb += verdaux_size;
}
return pb;
}
// Verneed methods.
Verneed::~Verneed()
{
for (Need_versions::iterator p = this->need_versions_.begin();
p != this->need_versions_.end();
++p)
delete *p;
}
// Add a new version to this file reference.
Verneed_version*
Verneed::add_name(const char* name)
{
Verneed_version* vv = new Verneed_version(name);
this->need_versions_.push_back(vv);
return vv;
}
// Set the version indexes starting at INDEX.
unsigned int
Verneed::finalize(unsigned int index)
{
for (Need_versions::iterator p = this->need_versions_.begin();
p != this->need_versions_.end();
++p)
{
(*p)->set_index(index);
++index;
}
return index;
}
// Write this list of referenced versions to a buffer for the output
// section.
template<int size, bool big_endian>
unsigned char*
Verneed::write(const Stringpool* dynpool, bool is_last,
unsigned char* pb) const
{
const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size;
const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size;
elfcpp::Verneed_write<size, big_endian> vn(pb);
vn.set_vn_version(elfcpp::VER_NEED_CURRENT);
vn.set_vn_cnt(this->need_versions_.size());
vn.set_vn_file(dynpool->get_offset(this->filename()));
vn.set_vn_aux(verneed_size);
vn.set_vn_next(is_last
? 0
: verneed_size + this->need_versions_.size() * vernaux_size);
pb += verneed_size;
Need_versions::const_iterator p;
unsigned int i;
for (p = this->need_versions_.begin(), i = 0;
p != this->need_versions_.end();
++p, ++i)
{
elfcpp::Vernaux_write<size, big_endian> vna(pb);
vna.set_vna_hash(Dynobj::elf_hash((*p)->version()));
// FIXME: We need to sometimes set VER_FLG_WEAK here.
vna.set_vna_flags(0);
vna.set_vna_other((*p)->index());
vna.set_vna_name(dynpool->get_offset((*p)->version()));
vna.set_vna_next(i + 1 >= this->need_versions_.size()
? 0
: vernaux_size);
pb += vernaux_size;
}
return pb;
}
// Versions methods.
Versions::Versions(const Version_script_info& version_script,
Stringpool* dynpool)
: defs_(), needs_(), version_table_(),
is_finalized_(false), version_script_(version_script),
needs_base_version_(true)
{
if (!this->version_script_.empty())
{
// Parse the version script, and insert each declared version into
// defs_ and version_table_.
std::vector<std::string> versions = this->version_script_.get_versions();
if (this->needs_base_version_ && !versions.empty())
this->define_base_version(dynpool);
for (size_t k = 0; k < versions.size(); ++k)
{
Stringpool::Key version_key;
const char* version = dynpool->add(versions[k].c_str(),
true, &version_key);
Verdef* const vd = new Verdef(
version,
this->version_script_.get_dependencies(version),
false, false, false, false);
this->defs_.push_back(vd);
Key key(version_key, 0);
this->version_table_.insert(std::make_pair(key, vd));
}
}
}
Versions::~Versions()
{
for (Defs::iterator p = this->defs_.begin();
p != this->defs_.end();
++p)
delete *p;
for (Needs::iterator p = this->needs_.begin();
p != this->needs_.end();
++p)
delete *p;
}
// Define the base version of a shared library. The base version definition
// must be the first entry in defs_. We insert it lazily so that defs_ is
// empty if no symbol versioning is used. Then layout can just drop the
// version sections.
void
Versions::define_base_version(Stringpool* dynpool)
{
// If we do any versioning at all, we always need a base version, so
// define that first. Nothing explicitly declares itself as part of base,
// so it doesn't need to be in version_table_.
gold_assert(this->defs_.empty());
const char* name = parameters->options().soname();
if (name == NULL)
name = parameters->options().output_file_name();
name = dynpool->add(name, false, NULL);
Verdef* vdbase = new Verdef(name, std::vector<std::string>(),
true, false, false, true);
this->defs_.push_back(vdbase);
this->needs_base_version_ = false;
}
// Return the dynamic object which a symbol refers to.
Dynobj*
Versions::get_dynobj_for_sym(const Symbol_table* symtab,
const Symbol* sym) const
{
if (sym->is_copied_from_dynobj())
return symtab->get_copy_source(sym);
else
{
Object* object = sym->object();
gold_assert(object->is_dynamic());
return static_cast<Dynobj*>(object);
}
}
// Record version information for a symbol going into the dynamic
// symbol table.
void
Versions::record_version(const Symbol_table* symtab,
Stringpool* dynpool, const Symbol* sym)
{
gold_assert(!this->is_finalized_);
gold_assert(sym->version() != NULL);
// A symbol defined as "sym@" is bound to an unspecified base version.
if (sym->version()[0] == '\0')
return;
Stringpool::Key version_key;
const char* version = dynpool->add(sym->version(), false, &version_key);
if (!sym->is_from_dynobj() && !sym->is_copied_from_dynobj())
{
this->add_def(dynpool, sym, version, version_key);
}
else
{
// This is a version reference.
Dynobj* dynobj = this->get_dynobj_for_sym(symtab, sym);
this->add_need(dynpool, dynobj->soname(), version, version_key);
}
}
// We've found a symbol SYM defined in version VERSION.
void
Versions::add_def(Stringpool* dynpool, const Symbol* sym, const char* version,
Stringpool::Key version_key)
{
Key k(version_key, 0);
Version_base* const vbnull = NULL;
std::pair<Version_table::iterator, bool> ins =
this->version_table_.insert(std::make_pair(k, vbnull));
if (!ins.second)
{
// We already have an entry for this version.
Version_base* vb = ins.first->second;
// We have now seen a symbol in this version, so it is not
// weak.
gold_assert(vb != NULL);
vb->clear_weak();
}
else
{
// If we are creating a shared object, it is an error to
// find a definition of a symbol with a version which is not
// in the version script.
if (parameters->options().shared())
gold_error(_("symbol %s has undefined version %s"),
sym->demangled_name().c_str(), version);
// When creating a regular executable, automatically define
// a new version.
if (this->needs_base_version_)
this->define_base_version(dynpool);
Verdef* vd = new Verdef(version, std::vector<std::string>(),
false, false, false, false);
this->defs_.push_back(vd);
ins.first->second = vd;
}
}
// Add a reference to version NAME in file FILENAME.
void
Versions::add_need(Stringpool* dynpool, const char* filename, const char* name,
Stringpool::Key name_key)
{
Stringpool::Key filename_key;
filename = dynpool->add(filename, true, &filename_key);
Key k(name_key, filename_key);
Version_base* const vbnull = NULL;
std::pair<Version_table::iterator, bool> ins =
this->version_table_.insert(std::make_pair(k, vbnull));
if (!ins.second)
{
// We already have an entry for this filename/version.
return;
}
// See whether we already have this filename. We don't expect many
// version references, so we just do a linear search. This could be
// replaced by a hash table.
Verneed* vn = NULL;
for (Needs::iterator p = this->needs_.begin();
p != this->needs_.end();
++p)
{
if ((*p)->filename() == filename)
{
vn = *p;
break;
}
}
if (vn == NULL)
{
// Create base version definition lazily for shared library.
if (parameters->options().shared() && this->needs_base_version_)
this->define_base_version(dynpool);
// We have a new filename.
vn = new Verneed(filename);
this->needs_.push_back(vn);
}
ins.first->second = vn->add_name(name);
}
// Set the version indexes. Create a new dynamic version symbol for
// each new version definition.
unsigned int
Versions::finalize(Symbol_table* symtab, unsigned int dynsym_index,
std::vector<Symbol*>* syms)
{
gold_assert(!this->is_finalized_);
unsigned int vi = 1;
for (Defs::iterator p = this->defs_.begin();
p != this->defs_.end();
++p)
{
(*p)->set_index(vi);
++vi;
// Create a version symbol if necessary.
if (!(*p)->is_symbol_created())
{
Symbol* vsym = symtab->define_as_constant((*p)->name(),
(*p)->name(),
Symbol_table::PREDEFINED,
0, 0,
elfcpp::STT_OBJECT,
elfcpp::STB_GLOBAL,
elfcpp::STV_DEFAULT, 0,
false, false);
vsym->set_needs_dynsym_entry();
vsym->set_dynsym_index(dynsym_index);
vsym->set_is_default();
++dynsym_index;
syms->push_back(vsym);
// The name is already in the dynamic pool.
}
}
// Index 1 is used for global symbols.
if (vi == 1)
{
gold_assert(this->defs_.empty());
vi = 2;
}
for (Needs::iterator p = this->needs_.begin();
p != this->needs_.end();
++p)
vi = (*p)->finalize(vi);
this->is_finalized_ = true;
return dynsym_index;
}
// Return the version index to use for a symbol. This does two hash
// table lookups: one in DYNPOOL and one in this->version_table_.
// Another approach alternative would be store a pointer in SYM, which
// would increase the size of the symbol table. Or perhaps we could
// use a hash table from dynamic symbol pointer values to Version_base
// pointers.
unsigned int
Versions::version_index(const Symbol_table* symtab, const Stringpool* dynpool,
const Symbol* sym) const
{
Stringpool::Key version_key;
const char* version = dynpool->find(sym->version(), &version_key);
gold_assert(version != NULL);
Key k;
if (!sym->is_from_dynobj() && !sym->is_copied_from_dynobj())
{
k = Key(version_key, 0);
}
else
{
Dynobj* dynobj = this->get_dynobj_for_sym(symtab, sym);
Stringpool::Key filename_key;
const char* filename = dynpool->find(dynobj->soname(), &filename_key);
gold_assert(filename != NULL);
k = Key(version_key, filename_key);
}
Version_table::const_iterator p = this->version_table_.find(k);
gold_assert(p != this->version_table_.end());
return p->second->index();
}
// Return an allocated buffer holding the contents of the symbol
// version section.
template<int size, bool big_endian>
void
Versions::symbol_section_contents(const Symbol_table* symtab,
const Stringpool* dynpool,
unsigned int local_symcount,
const std::vector<Symbol*>& syms,
unsigned char** pp,
unsigned int* psize) const
{
gold_assert(this->is_finalized_);
unsigned int sz = (local_symcount + syms.size()) * 2;
unsigned char* pbuf = new unsigned char[sz];
for (unsigned int i = 0; i < local_symcount; ++i)
elfcpp::Swap<16, big_endian>::writeval(pbuf + i * 2,
elfcpp::VER_NDX_LOCAL);
for (std::vector<Symbol*>::const_iterator p = syms.begin();
p != syms.end();
++p)
{
unsigned int version_index;
const char* version = (*p)->version();
if (version == NULL)
{
if ((*p)->is_defined() && !(*p)->is_from_dynobj())
version_index = elfcpp::VER_NDX_GLOBAL;
else
version_index = elfcpp::VER_NDX_LOCAL;
}
else if (version[0] == '\0')
version_index = elfcpp::VER_NDX_GLOBAL;
else
version_index = this->version_index(symtab, dynpool, *p);
// If the symbol was defined as foo@V1 instead of foo@@V1, add
// the hidden bit.
if ((*p)->version() != NULL
&& (*p)->is_defined()
&& !(*p)->is_default()
&& !(*p)->from_dyn())
version_index |= elfcpp::VERSYM_HIDDEN;
elfcpp::Swap<16, big_endian>::writeval(pbuf + (*p)->dynsym_index() * 2,
version_index);
}
*pp = pbuf;
*psize = sz;
}
// Return an allocated buffer holding the contents of the version
// definition section.
template<int size, bool big_endian>
void
Versions::def_section_contents(const Stringpool* dynpool,
unsigned char** pp, unsigned int* psize,
unsigned int* pentries) const
{
gold_assert(this->is_finalized_);
gold_assert(!this->defs_.empty());
const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size;
const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size;
unsigned int sz = 0;
for (Defs::const_iterator p = this->defs_.begin();
p != this->defs_.end();
++p)
{
sz += verdef_size + verdaux_size;
sz += (*p)->count_dependencies() * verdaux_size;
}
unsigned char* pbuf = new unsigned char[sz];
unsigned char* pb = pbuf;
Defs::const_iterator p;
unsigned int i;
for (p = this->defs_.begin(), i = 0;
p != this->defs_.end();
++p, ++i)
pb = (*p)->write<size, big_endian>(dynpool,
i + 1 >= this->defs_.size(),
pb);
gold_assert(static_cast<unsigned int>(pb - pbuf) == sz);
*pp = pbuf;
*psize = sz;
*pentries = this->defs_.size();
}
// Return an allocated buffer holding the contents of the version
// reference section.
template<int size, bool big_endian>
void
Versions::need_section_contents(const Stringpool* dynpool,
unsigned char** pp, unsigned int* psize,
unsigned int* pentries) const
{
gold_assert(this->is_finalized_);
gold_assert(!this->needs_.empty());
const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size;
const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size;
unsigned int sz = 0;
for (Needs::const_iterator p = this->needs_.begin();
p != this->needs_.end();
++p)
{
sz += verneed_size;
sz += (*p)->count_versions() * vernaux_size;
}
unsigned char* pbuf = new unsigned char[sz];
unsigned char* pb = pbuf;
Needs::const_iterator p;
unsigned int i;
for (p = this->needs_.begin(), i = 0;
p != this->needs_.end();
++p, ++i)
pb = (*p)->write<size, big_endian>(dynpool,
i + 1 >= this->needs_.size(),
pb);
gold_assert(static_cast<unsigned int>(pb - pbuf) == sz);
*pp = pbuf;
*psize = sz;
*pentries = this->needs_.size();
}
// Instantiate the templates we need. We could use the configure
// script to restrict this to only the ones for implemented targets.
#ifdef HAVE_TARGET_32_LITTLE
template
class Sized_dynobj<32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Sized_dynobj<32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Sized_dynobj<64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Sized_dynobj<64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
void
Versions::symbol_section_contents<32, false>(
const Symbol_table*,
const Stringpool*,
unsigned int,
const std::vector<Symbol*>&,
unsigned char**,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
Versions::symbol_section_contents<32, true>(
const Symbol_table*,
const Stringpool*,
unsigned int,
const std::vector<Symbol*>&,
unsigned char**,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
Versions::symbol_section_contents<64, false>(
const Symbol_table*,
const Stringpool*,
unsigned int,
const std::vector<Symbol*>&,
unsigned char**,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
Versions::symbol_section_contents<64, true>(
const Symbol_table*,
const Stringpool*,
unsigned int,
const std::vector<Symbol*>&,
unsigned char**,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
void
Versions::def_section_contents<32, false>(
const Stringpool*,
unsigned char**,
unsigned int*,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
Versions::def_section_contents<32, true>(
const Stringpool*,
unsigned char**,
unsigned int*,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
Versions::def_section_contents<64, false>(
const Stringpool*,
unsigned char**,
unsigned int*,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
Versions::def_section_contents<64, true>(
const Stringpool*,
unsigned char**,
unsigned int*,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
void
Versions::need_section_contents<32, false>(
const Stringpool*,
unsigned char**,
unsigned int*,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
Versions::need_section_contents<32, true>(
const Stringpool*,
unsigned char**,
unsigned int*,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
Versions::need_section_contents<64, false>(
const Stringpool*,
unsigned char**,
unsigned int*,
unsigned int*) const;
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
Versions::need_section_contents<64, true>(
const Stringpool*,
unsigned char**,
unsigned int*,
unsigned int*) const;
#endif
} // End namespace gold.
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