// object.cc -- support for an object file for linking in gold
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "demangle.h"
#include "libiberty.h"
+#include "gc.h"
#include "target-select.h"
#include "dwarf_reader.h"
#include "layout.h"
{
Location loc(this->do_section_contents(shndx));
*plen = convert_to_section_size_type(loc.data_size);
+ if (*plen == 0)
+ {
+ static const unsigned char empty[1] = { '\0' };
+ return empty;
+ }
return this->get_view(loc.file_offset, *plen, true, cache);
}
section_size_type len;
const unsigned char* contents = this->section_contents(shndx, &len,
false);
+ if (len == 0)
+ {
+ const char* warning = name + warn_prefix_len;
+ contents = reinterpret_cast<const unsigned char*>(warning);
+ len = strlen(warning);
+ }
std::string warning(reinterpret_cast<const char*>(contents), len);
symtab->add_warning(name + warn_prefix_len, this, warning);
return true;
return false;
}
+// Class Relobj
+
+// To copy the symbols data read from the file to a local data structure.
+// This function is called from do_layout only while doing garbage
+// collection.
+
+void
+Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
+ unsigned int section_header_size)
+{
+ gc_sd->section_headers_data =
+ new unsigned char[(section_header_size)];
+ memcpy(gc_sd->section_headers_data, sd->section_headers->data(),
+ section_header_size);
+ gc_sd->section_names_data =
+ new unsigned char[sd->section_names_size];
+ memcpy(gc_sd->section_names_data, sd->section_names->data(),
+ sd->section_names_size);
+ gc_sd->section_names_size = sd->section_names_size;
+ if (sd->symbols != NULL)
+ {
+ gc_sd->symbols_data =
+ new unsigned char[sd->symbols_size];
+ memcpy(gc_sd->symbols_data, sd->symbols->data(),
+ sd->symbols_size);
+ }
+ else
+ {
+ gc_sd->symbols_data = NULL;
+ }
+ gc_sd->symbols_size = sd->symbols_size;
+ gc_sd->external_symbols_offset = sd->external_symbols_offset;
+ if (sd->symbol_names != NULL)
+ {
+ gc_sd->symbol_names_data =
+ new unsigned char[sd->symbol_names_size];
+ memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(),
+ sd->symbol_names_size);
+ }
+ else
+ {
+ gc_sd->symbol_names_data = NULL;
+ }
+ gc_sd->symbol_names_size = sd->symbol_names_size;
+}
+
+// This function determines if a particular section name must be included
+// in the link. This is used during garbage collection to determine the
+// roots of the worklist.
+
+bool
+Relobj::is_section_name_included(const char* name)
+{
+ if (is_prefix_of(".ctors", name)
+ || is_prefix_of(".dtors", name)
+ || is_prefix_of(".note", name)
+ || is_prefix_of(".init", name)
+ || is_prefix_of(".fini", name)
+ || is_prefix_of(".gcc_except_table", name)
+ || is_prefix_of(".jcr", name)
+ || is_prefix_of(".preinit_array", name)
+ || (is_prefix_of(".text", name)
+ && strstr(name, "personality"))
+ || (is_prefix_of(".data", name)
+ && strstr(name, "personality"))
+ || (is_prefix_of(".gnu.linkonce.d", name) &&
+ strstr(name, "personality")))
+ {
+ return true;
+ }
+ return false;
+}
+
// Class Sized_relobj.
template<int size, bool big_endian>
local_values_(),
local_got_offsets_(),
kept_comdat_sections_(),
- comdat_groups_(),
- has_eh_frame_(false)
+ has_eh_frame_(false),
+ discarded_eh_frame_shndx_(-1U)
{
}
// Record this section group in the layout, and see whether we've already
// seen one with the same signature.
- bool include_group = ((flags & elfcpp::GRP_COMDAT) == 0
- || layout->add_comdat(this, index, signature, true));
-
- Sized_relobj<size, big_endian>* kept_object = NULL;
- Comdat_group* kept_group = NULL;
+ bool include_group;
+ bool is_comdat;
+ Kept_section* kept_section = NULL;
- if (!include_group)
+ if ((flags & elfcpp::GRP_COMDAT) == 0)
{
- // This group is being discarded. Find the object and group
- // that was kept in its place.
- unsigned int kept_group_index = 0;
- Relobj* kept_relobj = layout->find_kept_object(signature,
- &kept_group_index);
- kept_object = static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
- if (kept_object != NULL)
- kept_group = kept_object->find_comdat_group(kept_group_index);
+ include_group = true;
+ is_comdat = false;
}
- else if (flags & elfcpp::GRP_COMDAT)
+ else
{
- // This group is being kept. Create the table to map section names
- // to section indexes and add it to the table of groups.
- kept_group = new Comdat_group();
- this->add_comdat_group(index, kept_group);
+ include_group = layout->find_or_add_kept_section(signature,
+ this, index, true,
+ true, &kept_section);
+ is_comdat = true;
}
size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
for (size_t i = 1; i < count; ++i)
{
- elfcpp::Elf_Word secnum =
+ elfcpp::Elf_Word shndx =
this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
if (relocate_group)
- shndxes.push_back(secnum);
+ shndxes.push_back(shndx);
- if (secnum >= this->shnum())
+ if (shndx >= this->shnum())
{
this->error(_("section %u in section group %u out of range"),
- secnum, index);
+ shndx, index);
continue;
}
// Check for an earlier section number, since we're going to get
// it wrong--we may have already decided to include the section.
- if (secnum < index)
+ if (shndx < index)
this->error(_("invalid section group %u refers to earlier section %u"),
- index, secnum);
+ index, shndx);
// Get the name of the member section.
- typename This::Shdr member_shdr(shdrs + secnum * This::shdr_size);
+ typename This::Shdr member_shdr(shdrs + shndx * This::shdr_size);
if (member_shdr.get_sh_name() >= section_names_size)
{
// This is an error, but it will be diagnosed eventually
}
std::string mname(section_names + member_shdr.get_sh_name());
- if (!include_group)
+ if (include_group)
+ {
+ if (is_comdat)
+ kept_section->add_comdat_section(mname, shndx,
+ member_shdr.get_sh_size());
+ }
+ else
{
- (*omit)[secnum] = true;
- if (kept_group != NULL)
+ (*omit)[shndx] = true;
+
+ if (is_comdat)
{
- // Find the corresponding kept section, and store that info
- // in the discarded section table.
- Comdat_group::const_iterator p = kept_group->find(mname);
- if (p != kept_group->end())
- {
- Kept_comdat_section* kept =
- new Kept_comdat_section(kept_object, p->second);
- this->set_kept_comdat_section(secnum, kept);
- }
+ Relobj* kept_object = kept_section->object();
+ if (kept_section->is_comdat())
+ {
+ // Find the corresponding kept section, and store
+ // that info in the discarded section table.
+ unsigned int kept_shndx;
+ uint64_t kept_size;
+ if (kept_section->find_comdat_section(mname, &kept_shndx,
+ &kept_size))
+ {
+ // We don't keep a mapping for this section if
+ // it has a different size. The mapping is only
+ // used for relocation processing, and we don't
+ // want to treat the sections as similar if the
+ // sizes are different. Checking the section
+ // size is the approach used by the GNU linker.
+ if (kept_size == member_shdr.get_sh_size())
+ this->set_kept_comdat_section(shndx, kept_object,
+ kept_shndx);
+ }
+ }
+ else
+ {
+ // The existing section is a linkonce section. Add
+ // a mapping if there is exactly one section in the
+ // group (which is true when COUNT == 2) and if it
+ // is the same size.
+ if (count == 2
+ && (kept_section->linkonce_size()
+ == member_shdr.get_sh_size()))
+ this->set_kept_comdat_section(shndx, kept_object,
+ kept_section->shndx());
+ }
}
}
- else if (flags & elfcpp::GRP_COMDAT)
- {
- // Add the section to the kept group table.
- gold_assert(kept_group != NULL);
- kept_group->insert(std::make_pair(mname, secnum));
- }
}
if (relocate_group)
Layout* layout,
unsigned int index,
const char* name,
- const elfcpp::Shdr<size, big_endian>&)
+ const elfcpp::Shdr<size, big_endian>& shdr)
{
+ typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
// In general the symbol name we want will be the string following
// the last '.'. However, we have to handle the case of
// .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
symname = strrchr(name, '.') + 1;
std::string sig1(symname);
std::string sig2(name);
- bool include1 = layout->add_comdat(this, index, sig1, false);
- bool include2 = layout->add_comdat(this, index, sig2, true);
+ Kept_section* kept1;
+ Kept_section* kept2;
+ bool include1 = layout->find_or_add_kept_section(sig1, this, index, false,
+ false, &kept1);
+ bool include2 = layout->find_or_add_kept_section(sig2, this, index, false,
+ true, &kept2);
if (!include2)
{
- // The section is being discarded on the basis of its section
- // name (i.e., the kept section was also a linkonce section).
- // In this case, the section index stored with the layout object
- // is the linkonce section that was kept.
- unsigned int kept_group_index = 0;
- Relobj* kept_relobj = layout->find_kept_object(sig2, &kept_group_index);
- if (kept_relobj != NULL)
- {
- Sized_relobj<size, big_endian>* kept_object
- = static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
- Kept_comdat_section* kept =
- new Kept_comdat_section(kept_object, kept_group_index);
- this->set_kept_comdat_section(index, kept);
- }
+ // We are not including this section because we already saw the
+ // name of the section as a signature. This normally implies
+ // that the kept section is another linkonce section. If it is
+ // the same size, record it as the section which corresponds to
+ // this one.
+ if (kept2->object() != NULL
+ && !kept2->is_comdat()
+ && kept2->linkonce_size() == sh_size)
+ this->set_kept_comdat_section(index, kept2->object(), kept2->shndx());
}
else if (!include1)
{
// this linkonce section. We'll handle the simple case where
// the group has only one member section. Otherwise, it's not
// worth the effort.
- unsigned int kept_group_index = 0;
- Relobj* kept_relobj = layout->find_kept_object(sig1, &kept_group_index);
- if (kept_relobj != NULL)
- {
- Sized_relobj<size, big_endian>* kept_object =
- static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
- Comdat_group* kept_group =
- kept_object->find_comdat_group(kept_group_index);
- if (kept_group != NULL && kept_group->size() == 1)
- {
- Comdat_group::const_iterator p = kept_group->begin();
- gold_assert(p != kept_group->end());
- Kept_comdat_section* kept =
- new Kept_comdat_section(kept_object, p->second);
- this->set_kept_comdat_section(index, kept);
- }
- }
+ unsigned int kept_shndx;
+ uint64_t kept_size;
+ if (kept1->object() != NULL
+ && kept1->is_comdat()
+ && kept1->find_single_comdat_section(&kept_shndx, &kept_size)
+ && kept_size == sh_size)
+ this->set_kept_comdat_section(index, kept1->object(), kept_shndx);
+ }
+ else
+ {
+ kept1->set_linkonce_size(sh_size);
+ kept2->set_linkonce_size(sh_size);
}
return include1 && include2;
// Lay out the input sections. We walk through the sections and check
// whether they should be included in the link. If they should, we
// pass them to the Layout object, which will return an output section
-// and an offset.
+// and an offset.
+// During garbage collection (gc-sections), this function is called
+// twice. When it is called the first time, it is for setting up some
+// sections as roots to a work-list and to do comdat processing. Actual
+// layout happens the second time around after all the relevant sections
+// have been determined. The first time, is_worklist_ready is false.
+// It is then set to true after the worklist is processed and the relevant
+// sections are determined. Then, this function is called again to
+// layout the sections.
template<int size, bool big_endian>
void
Read_symbols_data* sd)
{
const unsigned int shnum = this->shnum();
+ bool is_gc_pass_one = (parameters->options().gc_sections()
+ && !symtab->gc()->is_worklist_ready());
+ bool is_gc_pass_two = (parameters->options().gc_sections()
+ && symtab->gc()->is_worklist_ready());
if (shnum == 0)
return;
+ Symbols_data* gc_sd = NULL;
+ if (is_gc_pass_one)
+ {
+ // During garbage collection save the symbols data to use it when
+ // re-entering this function.
+ gc_sd = new Symbols_data;
+ this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
+ this->set_symbols_data(gc_sd);
+ }
+ else if (is_gc_pass_two)
+ {
+ gc_sd = this->get_symbols_data();
+ }
+
+ const unsigned char* section_headers_data = NULL;
+ section_size_type section_names_size;
+ const unsigned char* symbols_data = NULL;
+ section_size_type symbols_size;
+ section_offset_type external_symbols_offset;
+ const unsigned char* symbol_names_data = NULL;
+ section_size_type symbol_names_size;
+
+ if (parameters->options().gc_sections())
+ {
+ section_headers_data = gc_sd->section_headers_data;
+ section_names_size = gc_sd->section_names_size;
+ symbols_data = gc_sd->symbols_data;
+ symbols_size = gc_sd->symbols_size;
+ external_symbols_offset = gc_sd->external_symbols_offset;
+ symbol_names_data = gc_sd->symbol_names_data;
+ symbol_names_size = gc_sd->symbol_names_size;
+ }
+ else
+ {
+ section_headers_data = sd->section_headers->data();
+ section_names_size = sd->section_names_size;
+ if (sd->symbols != NULL)
+ symbols_data = sd->symbols->data();
+ symbols_size = sd->symbols_size;
+ external_symbols_offset = sd->external_symbols_offset;
+ if (sd->symbol_names != NULL)
+ symbol_names_data = sd->symbol_names->data();
+ symbol_names_size = sd->symbol_names_size;
+ }
// Get the section headers.
- const unsigned char* shdrs = sd->section_headers->data();
+ const unsigned char* shdrs = section_headers_data;
const unsigned char* pshdrs;
// Get the section names.
- const unsigned char* pnamesu = sd->section_names->data();
+ const unsigned char* pnamesu = parameters->options().gc_sections() ?
+ gc_sd->section_names_data :
+ sd->section_names->data();
const char* pnames = reinterpret_cast<const char*>(pnamesu);
// If any input files have been claimed by plugins, we need to defer
Output_sections& out_sections(this->output_sections());
std::vector<Address>& out_section_offsets(this->section_offsets_);
- out_sections.resize(shnum);
- out_section_offsets.resize(shnum);
+ if (!is_gc_pass_two)
+ {
+ out_sections.resize(shnum);
+ out_section_offsets.resize(shnum);
+ }
// If we are only linking for symbols, then there is nothing else to
// do here.
if (this->input_file()->just_symbols())
{
- delete sd->section_headers;
- sd->section_headers = NULL;
- delete sd->section_names;
- sd->section_names = NULL;
+ if (!is_gc_pass_two)
+ {
+ delete sd->section_headers;
+ sd->section_headers = NULL;
+ delete sd->section_names;
+ sd->section_names = NULL;
+ }
return;
}
{
typename This::Shdr shdr(pshdrs);
- if (shdr.get_sh_name() >= sd->section_names_size)
+ if (shdr.get_sh_name() >= section_names_size)
{
this->error(_("bad section name offset for section %u: %lu"),
i, static_cast<unsigned long>(shdr.get_sh_name()));
const char* name = pnames + shdr.get_sh_name();
- if (this->handle_gnu_warning_section(name, i, symtab))
- {
- if (!relocatable)
- omit[i] = true;
- }
+ if (!is_gc_pass_two)
+ {
+ if (this->handle_gnu_warning_section(name, i, symtab))
+ {
+ if (!relocatable)
+ omit[i] = true;
+ }
- // The .note.GNU-stack section is special. It gives the
- // protection flags that this object file requires for the stack
- // in memory.
- if (strcmp(name, ".note.GNU-stack") == 0)
- {
- seen_gnu_stack = true;
- gnu_stack_flags |= shdr.get_sh_flags();
- omit[i] = true;
- }
+ // The .note.GNU-stack section is special. It gives the
+ // protection flags that this object file requires for the stack
+ // in memory.
+ if (strcmp(name, ".note.GNU-stack") == 0)
+ {
+ seen_gnu_stack = true;
+ gnu_stack_flags |= shdr.get_sh_flags();
+ omit[i] = true;
+ }
- bool discard = omit[i];
- if (!discard)
- {
- if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
- {
- if (!this->include_section_group(symtab, layout, i, name, shdrs,
- pnames, sd->section_names_size,
- &omit))
- discard = true;
- }
- else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
- && Layout::is_linkonce(name))
- {
- if (!this->include_linkonce_section(layout, i, name, shdr))
- discard = true;
+ bool discard = omit[i];
+ if (!discard)
+ {
+ if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
+ {
+ if (!this->include_section_group(symtab, layout, i, name,
+ shdrs, pnames,
+ section_names_size,
+ &omit))
+ discard = true;
+ }
+ else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
+ && Layout::is_linkonce(name))
+ {
+ if (!this->include_linkonce_section(layout, i, name, shdr))
+ discard = true;
+ }
}
- }
- if (discard)
- {
- // Do not include this section in the link.
- out_sections[i] = NULL;
- out_section_offsets[i] = invalid_address;
- continue;
- }
+ if (discard)
+ {
+ // Do not include this section in the link.
+ out_sections[i] = NULL;
+ out_section_offsets[i] = invalid_address;
+ continue;
+ }
+ }
+
+ if (is_gc_pass_one)
+ {
+ if (is_section_name_included(name)
+ || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY
+ || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
+ {
+ symtab->gc()->worklist().push(Section_id(this, i));
+ }
+ }
// When doing a relocatable link we are going to copy input
// reloc sections into the output. We only want to copy the
// ones associated with sections which are not being discarded.
// However, we don't know that yet for all sections. So save
- // reloc sections and process them later.
+ // reloc sections and process them later. Garbage collection is
+ // not triggered when relocatable code is desired.
if (emit_relocs
&& (shdr.get_sh_type() == elfcpp::SHT_REL
|| shdr.get_sh_type() == elfcpp::SHT_RELA))
// determine which sections are being discarded, and discard the
// corresponding information.
if (!relocatable
- && strcmp(name, ".eh_frame") == 0
- && this->check_eh_frame_flags(&shdr))
- {
- eh_frame_sections.push_back(i);
- continue;
- }
+ && strcmp(name, ".eh_frame") == 0
+ && this->check_eh_frame_flags(&shdr))
+ {
+ if (is_gc_pass_one)
+ {
+ out_sections[i] = reinterpret_cast<Output_section*>(1);
+ out_section_offsets[i] = invalid_address;
+ }
+ else
+ eh_frame_sections.push_back(i);
+ continue;
+ }
+ if (is_gc_pass_two)
+ {
+ // This is executed during the second pass of garbage
+ // collection. do_layout has been called before and some
+ // sections have been already discarded. Simply ignore
+ // such sections this time around.
+ if (out_sections[i] == NULL)
+ {
+ gold_assert(out_section_offsets[i] == invalid_address);
+ continue;
+ }
+ if ((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
+ if (symtab->gc()->referenced_list().find(Section_id(this,i))
+ == symtab->gc()->referenced_list().end())
+ {
+ if (parameters->options().print_gc_sections())
+ gold_info(_("%s: removing unused section from '%s'"
+ " in file '%s"),
+ program_name, this->section_name(i).c_str(),
+ this->name().c_str());
+ out_sections[i] = NULL;
+ out_section_offsets[i] = invalid_address;
+ continue;
+ }
+ }
+ // Defer layout here if input files are claimed by plugins. When gc
+ // is turned on this function is called twice. For the second call
+ // should_defer_layout should be false.
if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
{
- this->deferred_layout_.push_back(Deferred_layout(i, name, pshdrs,
+ gold_assert(!is_gc_pass_two);
+ this->deferred_layout_.push_back(Deferred_layout(i, name,
+ pshdrs,
reloc_shndx[i],
reloc_type[i]));
-
// Put dummy values here; real values will be supplied by
// do_layout_deferred_sections.
+ out_sections[i] = reinterpret_cast<Output_section*>(2);
+ out_section_offsets[i] = invalid_address;
+ continue;
+ }
+ // During gc_pass_two if a section that was previously deferred is
+ // found, do not layout the section as layout_deferred_sections will
+ // do it later from gold.cc.
+ if (is_gc_pass_two
+ && (out_sections[i] == reinterpret_cast<Output_section*>(2)))
+ continue;
+
+ if (is_gc_pass_one)
+ {
+ // This is during garbage collection. The out_sections are
+ // assigned in the second call to this function.
out_sections[i] = reinterpret_cast<Output_section*>(1);
out_section_offsets[i] = invalid_address;
}
else
{
+ // When garbage collection is switched on the actual layout
+ // only happens in the second call.
this->layout_section(layout, i, name, shdr, reloc_shndx[i],
reloc_type[i]);
}
}
- layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
+ if (!is_gc_pass_one)
+ layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
// When doing a relocatable link handle the reloc sections at the
- // end.
+ // end. Garbage collection is not turned on for relocatable code.
if (emit_relocs)
this->size_relocatable_relocs();
+ gold_assert(!parameters->options().gc_sections() || reloc_sections.empty());
for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
p != reloc_sections.end();
++p)
{
unsigned int i = *p;
const unsigned char* pshdr;
- pshdr = sd->section_headers->data() + i * This::shdr_size;
+ pshdr = section_headers_data + i * This::shdr_size;
typename This::Shdr shdr(pshdr);
unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
}
// Handle the .eh_frame sections at the end.
+ gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
p != eh_frame_sections.end();
++p)
{
gold_assert(this->has_eh_frame_);
- gold_assert(sd->external_symbols_offset != 0);
+ gold_assert(external_symbols_offset != 0);
unsigned int i = *p;
const unsigned char *pshdr;
- pshdr = sd->section_headers->data() + i * This::shdr_size;
+ pshdr = section_headers_data + i * This::shdr_size;
typename This::Shdr shdr(pshdr);
off_t offset;
Output_section* os = layout->layout_eh_frame(this,
- sd->symbols->data(),
- sd->symbols_size,
- sd->symbol_names->data(),
- sd->symbol_names_size,
+ symbols_data,
+ symbols_size,
+ symbol_names_data,
+ symbol_names_size,
i, shdr,
reloc_shndx[i],
reloc_type[i],
&offset);
out_sections[i] = os;
if (offset == -1)
- out_section_offsets[i] = invalid_address;
+ {
+ // An object can contain at most one section holding exception
+ // frame information.
+ gold_assert(this->discarded_eh_frame_shndx_ == -1U);
+ this->discarded_eh_frame_shndx_ = i;
+ out_section_offsets[i] = invalid_address;
+ }
else
out_section_offsets[i] = convert_types<Address, off_t>(offset);
this->set_relocs_must_follow_section_writes();
}
- delete sd->section_headers;
- sd->section_headers = NULL;
- delete sd->section_names;
- sd->section_names = NULL;
+ if (is_gc_pass_two)
+ {
+ delete[] gc_sd->section_headers_data;
+ delete[] gc_sd->section_names_data;
+ delete[] gc_sd->symbols_data;
+ delete[] gc_sd->symbol_names_data;
+ }
+ else
+ {
+ delete sd->section_headers;
+ sd->section_headers = NULL;
+ delete sd->section_names;
+ sd->section_names = NULL;
+ }
}
// Layout sections whose layout was deferred while waiting for
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
- Read_symbols_data* sd)
+ Read_symbols_data* sd,
+ Layout*)
{
if (sd->symbols == NULL)
{
unsigned int dyncount = 0;
// Skip the first, dummy, symbol.
psyms += sym_size;
+ bool discard_locals = parameters->options().discard_locals();
for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
{
elfcpp::Sym<size, big_endian> sym(psyms);
// Decide whether this symbol should go into the output file.
- if (shndx < shnum && out_sections[shndx] == NULL)
+ if ((shndx < shnum && out_sections[shndx] == NULL)
+ || (shndx == this->discarded_eh_frame_shndx_))
{
lv.set_no_output_symtab_entry();
gold_assert(!lv.needs_output_dynsym_entry());
continue;
}
- // Add the symbol to the symbol table string pool.
+ // If --discard-locals option is used, discard all temporary local
+ // symbols. These symbols start with system-specific local label
+ // prefixes, typically .L for ELF system. We want to be compatible
+ // with GNU ld so here we essentially use the same check in
+ // bfd_is_local_label(). The code is different because we already
+ // know that:
+ //
+ // - the symbol is local and thus cannot have global or weak binding.
+ // - the symbol is not a section symbol.
+ // - the symbol has a name.
+ //
+ // We do not discard a symbol if it needs a dynamic symbol entry.
const char* name = pnames + sym.get_st_name();
+ if (discard_locals
+ && sym.get_st_type() != elfcpp::STT_FILE
+ && !lv.needs_output_dynsym_entry()
+ && parameters->target().is_local_label_name(name))
+ {
+ lv.set_no_output_symtab_entry();
+ continue;
+ }
+
+ // Add the symbol to the symbol table string pool.
pool->add(name, true, NULL);
++count;
const unsigned int loccount = this->local_symbol_count_;
this->local_symbol_offset_ = off;
+ const bool relocatable = parameters->options().relocatable();
const Output_sections& out_sections(this->output_sections());
const std::vector<Address>& out_offsets(this->section_offsets_);
unsigned int shnum = this->shnum();
if (!is_ordinary)
{
- if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)
+ if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
lv.set_output_value(lv.input_value());
else
{
}
else if (out_offsets[shndx] == invalid_address)
{
+ uint64_t start;
+
// This is a SHF_MERGE section or one which otherwise
- // requires special handling. We get the output address
- // of the start of the merged section. If this is not a
- // section symbol, we can then determine the final
- // value. If it is a section symbol, we can not, as in
- // that case we have to consider the addend to determine
- // the value to use in a relocation.
- if (!lv.is_section_symbol())
- lv.set_output_value(os->output_address(this, shndx,
- lv.input_value()));
+ // requires special handling.
+ if (shndx == this->discarded_eh_frame_shndx_)
+ {
+ // This local symbol belongs to a discarded .eh_frame
+ // section. Just treat it like the case in which
+ // os == NULL above.
+ gold_assert(this->has_eh_frame_);
+ continue;
+ }
+ else if (!lv.is_section_symbol())
+ {
+ // This is not a section symbol. We can determine
+ // the final value now.
+ lv.set_output_value(os->output_address(this, shndx,
+ lv.input_value()));
+ }
+ else if (!os->find_starting_output_address(this, shndx, &start))
+ {
+ // This is a section symbol, but apparently not one
+ // in a merged section. Just use the start of the
+ // output section. This happens with relocatable
+ // links when the input object has section symbols
+ // for arbitrary non-merge sections.
+ lv.set_output_value(os->address());
+ }
else
{
- section_offset_type start =
- os->starting_output_address(this, shndx);
+ // We have to consider the addend to determine the
+ // value to use in a relocation. START is the start
+ // of this input section.
Merged_symbol_value<size>* msv =
new Merged_symbol_value<size>(lv.input_value(), start);
lv.set_merged_symbol_value(msv);
+ out_offsets[shndx]
+ lv.input_value());
else
- lv.set_output_value(os->address()
+ lv.set_output_value((relocatable ? 0 : os->address())
+ out_offsets[shndx]
+ lv.input_value());
}
Output_symtab_xindex* symtab_xindex,
Output_symtab_xindex* dynsym_xindex)
{
- if (parameters->options().strip_all()
- && this->output_local_dynsym_count_ == 0)
- return;
+ const bool strip_all = parameters->options().strip_all();
+ if (strip_all)
+ {
+ if (this->output_local_dynsym_count_ == 0)
+ return;
+ this->output_local_symbol_count_ = 0;
+ }
gold_assert(this->symtab_shndx_ != -1U);
if (this->symtab_shndx_ == 0)
st_shndx = out_sections[st_shndx]->out_shndx();
if (st_shndx >= elfcpp::SHN_LORESERVE)
{
- if (lv.needs_output_symtab_entry())
+ if (lv.needs_output_symtab_entry() && !strip_all)
symtab_xindex->add(lv.output_symtab_index(), st_shndx);
if (lv.needs_output_dynsym_entry())
dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
}
// Write the symbol to the output symbol table.
- if (!parameters->options().strip_all()
- && lv.needs_output_symtab_entry())
+ if (!strip_all && lv.needs_output_symtab_entry())
{
elfcpp::Sym_write<size, big_endian> osym(ov);
unsigned int shndx,
bool* found) const
{
- Kept_comdat_section *kept = this->get_kept_comdat_section(shndx);
- if (kept != NULL)
+ Relobj* kept_object;
+ unsigned int kept_shndx;
+ if (this->get_kept_comdat_section(shndx, &kept_object, &kept_shndx))
{
- gold_assert(kept->object_ != NULL);
- *found = true;
- Output_section* os = kept->object_->output_section(kept->shndx_);
- Address offset = kept->object_->get_output_section_offset(kept->shndx_);
- gold_assert(os != NULL && offset != invalid_address);
- return os->address() + offset;
+ Sized_relobj<size, big_endian>* kept_relobj =
+ static_cast<Sized_relobj<size, big_endian>*>(kept_object);
+ Output_section* os = kept_relobj->output_section(kept_shndx);
+ Address offset = kept_relobj->get_output_section_offset(kept_shndx);
+ if (os != NULL && offset != invalid_address)
+ {
+ *found = true;
+ return os->address() + offset;
+ }
}
*found = false;
return 0;
}
this->dynobj_list_.push_back(dynobj);
-
- // If this is -lc, remember the directory in which we found it.
- // We use this when issuing warnings about undefined symbols: as
- // a heuristic, we don't warn about system libraries found in
- // the same directory as -lc.
- if (strncmp(soname, "libc.so", 7) == 0)
- {
- const char* object_name = dynobj->name().c_str();
- const char* base = lbasename(object_name);
- if (base != object_name)
- this->system_library_directory_.assign(object_name,
- base - 1 - object_name);
- }
}
// Add this object to the cross-referencer if requested.
return true;
}
-// Return whether an object was found in the system library directory.
-
-bool
-Input_objects::found_in_system_library_directory(const Object* object) const
-{
- return (!this->system_library_directory_.empty()
- && object->name().compare(0,
- this->system_library_directory_.size(),
- this->system_library_directory_) == 0);
-}
-
// For each dynamic object, record whether we've seen all of its
// explicit dependencies.
namespace gold
{
+// Return whether INPUT_FILE is an ELF object.
+
+bool
+is_elf_object(Input_file* input_file, off_t offset,
+ const unsigned char** start, int *read_size)
+{
+ off_t filesize = input_file->file().filesize();
+ int want = elfcpp::Elf_sizes<64>::ehdr_size;
+ if (filesize - offset < want)
+ want = filesize - offset;
+
+ const unsigned char* p = input_file->file().get_view(offset, 0, want,
+ true, false);
+ *start = p;
+ *read_size = want;
+
+ if (want < 4)
+ return false;
+
+ static unsigned char elfmagic[4] =
+ {
+ elfcpp::ELFMAG0, elfcpp::ELFMAG1,
+ elfcpp::ELFMAG2, elfcpp::ELFMAG3
+ };
+ return memcmp(p, elfmagic, 4) == 0;
+}
+
// Read an ELF file and return the appropriate instance of Object.
Object*
make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
- const unsigned char* p, section_offset_type bytes)
+ const unsigned char* p, section_offset_type bytes,
+ bool* punconfigured)
{
+ if (punconfigured != NULL)
+ *punconfigured = false;
+
if (bytes < elfcpp::EI_NIDENT)
{
gold_error(_("%s: ELF file too short"), name.c_str());
return make_elf_sized_object<32, true>(name, input_file,
offset, ehdr);
#else
- gold_error(_("%s: not configured to support "
- "32-bit big-endian object"),
- name.c_str());
+ if (punconfigured != NULL)
+ *punconfigured = true;
+ else
+ gold_error(_("%s: not configured to support "
+ "32-bit big-endian object"),
+ name.c_str());
return NULL;
#endif
}
return make_elf_sized_object<32, false>(name, input_file,
offset, ehdr);
#else
- gold_error(_("%s: not configured to support "
- "32-bit little-endian object"),
- name.c_str());
+ if (punconfigured != NULL)
+ *punconfigured = true;
+ else
+ gold_error(_("%s: not configured to support "
+ "32-bit little-endian object"),
+ name.c_str());
return NULL;
#endif
}
return make_elf_sized_object<64, true>(name, input_file,
offset, ehdr);
#else
- gold_error(_("%s: not configured to support "
- "64-bit big-endian object"),
- name.c_str());
+ if (punconfigured != NULL)
+ *punconfigured = true;
+ else
+ gold_error(_("%s: not configured to support "
+ "64-bit big-endian object"),
+ name.c_str());
return NULL;
#endif
}
return make_elf_sized_object<64, false>(name, input_file,
offset, ehdr);
#else
- gold_error(_("%s: not configured to support "
- "64-bit little-endian object"),
- name.c_str());
+ if (punconfigured != NULL)
+ *punconfigured = true;
+ else
+ gold_error(_("%s: not configured to support "
+ "64-bit little-endian object"),
+ name.c_str());
return NULL;
#endif
}