old-cross-binutils/gold/gold.cc
Ian Lance Taylor d491d34e93 * object.cc (Xindex::initialize_symtab_xindex): New function.
(Xindex::read_symtab_xindex): New function.
	(Xindex::sym_xindex_to_shndx): New function.
	(Sized_relobj::find_symtab): Pick up SHT_SYMTAB_SHNDX section if
	available.
	(Sized_relobj::do_initialize_xindex): New function.
	(Sized_relobj::do_read_symbols): Adjust section links.
	(Sized_relobj::symbol_section_and_value): Add is_ordinary
	parameter.  Change all callers.
	(Sized_relobj::include_section_group): Adjust section links and
	symbol section indexes.
	(Sized_relobj::do_layout): Adjust section links.
	(Sized_relobj::do_count_local_symbols): Adjust section links and
	symbol section indexes.
	(Sized_relobj::do_finalize_local_symbols): Distinguish between
	ordinary and special symbols.
	(Sized_relobj::write_local_symbols): Add symtab_xindex and
	dynsym_xindex parameters.  Change all callers.  Adjust section
	links.  Use SHN_XINDEX when needed.
	(Sized_relobj::get_symbol_location_info): Adjust section links.
	Don't get fooled by special symbols.
	* object.h (class Xindex): Define.
	(class Object): Add xindex_ parameter.  Declare virtual functoin
	do_initialize_xindex.
	(Object::adjust_sym_shndx): New function.
	(Object::set_xindex): New protected function.
	(class Symbol_value): Add is_ordinary_shndx_ field.
	(Symbol_value::Symbol_value): Initialize is_ordinary_shndx_.
	(Symbol_value::value): Assert ordinary section.
	(Symbol_value::initialize_input_to_output_map): Likewise.
	(Symbol_value::set_input_shndx): Add is_ordinary parameter.
	Change all callers.
	(Symbol_value::input_shndx): Add is_ordinary parameter.  Change
	all callers.
	(class Sized_relobj): Update declarations.
	(Sized_relobj::local_symbol_input_shndx): Add is_ordinary
	parameter.  Change all callers.
	(Sized_relobj::adjust_shndx): New function.
	* dynobj.cc (Sized_dynobj::Sized_dynobj): Initialize dynsym_shndx_
	field.
	(Sized_dynobj::find_dynsym_sections): Remove pdynsym_shndx
	parameter.  Change all callers.  Pick up SHT_DYNSYM_SHNDX section
	for SHT_DYNSYM section if available.  Set dynsym_shndx_ field.
	(Sized_dynobj::read_dynsym_section): Adjust section links.
	(Sized_dynobj::read_dynamic): Likewise.
	(Sized_dynobj::do_read_symbols): Use dynsym_shndx_ field.  Adjust
	section links.
	(Sized_dynobj::do_initialize_xindex): New function.
	* dynobj.h (class Sized_dynobj): Add dynsym_shndx_ field.  Declare
	do_initialize_xindex.
	(Sized_dynobj::adjust_shndx): New function.
	* layout.cc (Layout::Layout): Initialize symtab_xindex_ and
	dynsym_xindex_ fields.
	(Layout::finalize): Add a call to set_section_indexes before
	creating the symtab sections.
	(Layout::set_section_indexes): Don't do anything if the section
	already has a section index.
	(Layout::create_symtab_sections): Add shnum parameter.  Change
	caller.  Create .symtab_shndx section if needed.
	(Layout::create_shdrs): Add shstrtab_section parameter.  Change
	caller.
	(Layout::allocated_output_section_count): New function.
	(Layout::create_dynamic_symtab): Create .dynsym_shndx section if
	needed.
	* layout.h (class Layout): Add symtab_xindex_ and dynsym_xindex_
	fields.  Update declarations.
	(Layout::symtab_xindex): New function.
	(Layout::dynsym_xindex): New function.
	(class Write_symbols_task): Add layout_ field.
	(Write_symbols_task::Write_symbols_task): Add layout parameter.
	Change caller.
	* output.cc (Output_section_headers::Output_section_headers): Add
	shstrtab_section parameter.  Change all callers.
	(Output_section_headers::do_sized_write): Store overflow values
	for section count and section string table section index in
	section header zero.
	(Output_file_header::do_sized_write): Check for overflow of
	section count and section string table section index.
	(Output_symtab_xindex::do_write): New function.
	(Output_symtab_xindex::endian_do_write): New function.
	* output.h (class Output_section_headers): Add shstrtab_section_.
	Update declarations.
	(class Output_symtab_xindex): Define.
	(Output_section::has_out_shndx): New function.
	* symtab.cc (Symbol::init_fields): Initialize is_ordinary_shndx_
	field.
	(Symbol::init_base): Add st_shndx and is_ordinary parameters.
	Change all callers.
	(Sized_symbol::init): Likewise.
	(Symbol::output_section): Check for ordinary symbol.
	(Symbol_table::add_from_object): Remove orig_sym parameter.  Add
	st_shndx, is_ordinary, and orig_st_shndx parameters.  Change all
	callers.
	(Symbol_table::add_from_relobj): Add symndx_offset parameter.
	Change all callers.  Simplify handling of symbols from sections
	not included in the link.
	(Symbol_table::add_from_dynobj): Handle ordinary symbol
	distinction.
	(Weak_alias_sorter::operator()): Assert that symbols are
	ordinary.
	(Symbol_table::sized_finalize_symbol): Handle ordinary symbol
	distinction.
	(Symbol_table::write_globals): Add symtab_xindex and dynsym_xindex
	parameters.  Change all callers.
	(Symbol_table::sized_write_globals): Likewise.  Handle ordinary
	symbol distinction.  Use SHN_XINDEX when needed.
	(Symbol_table::write_section_symbol): Add symtab_xindex
	parameter.  Change all callers.
	(Symbol_table::sized_write_section_symbol): Likewise.  Use
	SHN_XINDEX when needed.
	* symtab.h (class Symbol): Add is_ordinary_shndx_ field.  Update
	declarations.
	(Symbol::shndx): Add is_ordinary parameter.  Change all callers.
	(Symbol::is_defined): Check is_ordinary.
	(Symbol::is_undefined, Symbol::is_weak_undefined): Likewise.
	(Symbol::is_absolute, Symbol::is_common): Likewise.
	(class Sized_symbol): Update declarations.
	(class Symbol_table): Update declarations.
	* resolve.cc (Symbol::override_base): Add st_shndx and is_ordinary
	parameters.  Change all callers.
	(Sized_symbol::override): Likewise.
	(Symbol_table::override): Likewise.
	(symbol_to_bits): Add is_ordinary parameter.  Change all callers.
	(Symbol_table::resolve): Remove orig_sym parameter.  Add st_shndx,
	is_ordinary, and orig_st_shndx parameters.  Change all callers.
	* copy-relocs.cc (Copy_relocs::emit_copy_reloc): Require symbol
	to be in an ordinary section.
	* dwarf_reader.cc (Sized_dwarf_line_info::symbol_section): Add
	object and is_ordinary parameters.  Change all callers.
	(Sized_dwarf_line_info::read_relocs): Add object parameter.
	Change all callers.  Don't add undefined or non-ordinary symbols
	to reloc_map_.
	(Sized_dwarf_line_info::read_line_mappings): Add object parameter.
	Change all callers.
	* dwarf_reader.h (class Sized_dwarf_line_info): Update
	declarations.
	* ehframe.cc (Eh_frame::read_fde): Check for ordinary symbol.
	* reloc.cc (Sized_relobj::do_read_relocs): Adjust section links.
	(Sized_relobj::relocate_sections): Likewise.
	* target-reloc.h (scan_relocs): Adjust section symbol index.
	(scan_relocatable_relocs): Likewise.
	* i386.cc (Scan::local): Check for ordinary symbols.
	* sparc.cc (Scan::local): Likewise.
	* x86_64.cc (Scan::local): Likewise.
	* testsuite/binary_unittest.cc (Sized_binary_test): Update calls
	to symbol_section_and_value.
	* testsuite/many_sections_test.cc: New file.
	* testsuite/Makefile.am (BUILT_SOURCES): Define.
	(check_PROGRAMS): Add many_sections_test.
	(many_sections_test_SOURCES): Define.
	(many_sections_test_DEPENDENCIES): Define.
	(many_sections_test_LDFLAGS): Define.
	(BUILT_SOURCES): Add many_sections_define.h.
	(many_sections_define.h): New target.
	(BUILT_SOURCES): Add many_sections_check.h.
	(many_sections_check.h): New target.
	(check_PROGRAMS): Add many_sections_r_test.
	(many_sections_r_test_SOURCES): Define.
	(many_sections_r_test_DEPENDENCIES): Define.
	(many_sections_r_test_LDFLAGS): Define.
	(many_sections_r_test_LDADD): Define.
	(many_sections_r_test.o): New target.
	* testsuite/Makefile.in: Rebuild.
2008-04-19 18:30:58 +00:00

377 lines
12 KiB
C++

// gold.cc -- main linker functions
// Copyright 2006, 2007, 2008 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 <cstdlib>
#include <cstdio>
#include <cstring>
#include <unistd.h>
#include <algorithm>
#include "libiberty.h"
#include "options.h"
#include "debug.h"
#include "workqueue.h"
#include "dirsearch.h"
#include "readsyms.h"
#include "symtab.h"
#include "common.h"
#include "object.h"
#include "layout.h"
#include "reloc.h"
#include "defstd.h"
namespace gold
{
const char* program_name;
void
gold_exit(bool status)
{
if (!status && parameters != NULL && parameters->options_valid())
unlink_if_ordinary(parameters->options().output_file_name());
exit(status ? EXIT_SUCCESS : EXIT_FAILURE);
}
void
gold_nomem()
{
// We are out of memory, so try hard to print a reasonable message.
// Note that we don't try to translate this message, since the
// translation process itself will require memory.
write(2, program_name, strlen(program_name));
const char* const s = ": out of memory\n";
write(2, s, strlen(s));
gold_exit(false);
}
// Handle an unreachable case.
void
do_gold_unreachable(const char* filename, int lineno, const char* function)
{
fprintf(stderr, _("%s: internal error in %s, at %s:%d\n"),
program_name, function, filename, lineno);
gold_exit(false);
}
// This class arranges to run the functions done in the middle of the
// link. It is just a closure.
class Middle_runner : public Task_function_runner
{
public:
Middle_runner(const General_options& options,
const Input_objects* input_objects,
Symbol_table* symtab,
Layout* layout)
: options_(options), input_objects_(input_objects), symtab_(symtab),
layout_(layout)
{ }
void
run(Workqueue*, const Task*);
private:
const General_options& options_;
const Input_objects* input_objects_;
Symbol_table* symtab_;
Layout* layout_;
};
void
Middle_runner::run(Workqueue* workqueue, const Task* task)
{
queue_middle_tasks(this->options_, task, this->input_objects_, this->symtab_,
this->layout_, workqueue);
}
// Queue up the initial set of tasks for this link job.
void
queue_initial_tasks(const General_options& options,
Dirsearch& search_path,
const Command_line& cmdline,
Workqueue* workqueue, Input_objects* input_objects,
Symbol_table* symtab, Layout* layout)
{
if (cmdline.begin() == cmdline.end())
gold_fatal(_("no input files"));
int thread_count = options.thread_count_initial();
if (thread_count == 0)
thread_count = cmdline.number_of_input_files();
workqueue->set_thread_count(thread_count);
// Read the input files. We have to add the symbols to the symbol
// table in order. We do this by creating a separate blocker for
// each input file. We associate the blocker with the following
// input file, to give us a convenient place to delete it.
Task_token* this_blocker = NULL;
for (Command_line::const_iterator p = cmdline.begin();
p != cmdline.end();
++p)
{
Task_token* next_blocker = new Task_token(true);
next_blocker->add_blocker();
workqueue->queue(new Read_symbols(options, input_objects, symtab, layout,
&search_path, &*p, NULL, this_blocker,
next_blocker));
this_blocker = next_blocker;
}
workqueue->queue(new Task_function(new Middle_runner(options,
input_objects,
symtab,
layout),
this_blocker,
"Task_function Middle_runner"));
}
// Queue up the middle set of tasks. These are the tasks which run
// after all the input objects have been found and all the symbols
// have been read, but before we lay out the output file.
void
queue_middle_tasks(const General_options& options,
const Task* task,
const Input_objects* input_objects,
Symbol_table* symtab,
Layout* layout,
Workqueue* workqueue)
{
// We have to support the case of not seeing any input objects, and
// generate an empty file. Existing builds depend on being able to
// pass an empty archive to the linker and get an empty object file
// out. In order to do this we need to use a default target.
if (input_objects->number_of_input_objects() == 0)
set_parameters_target(&parameters->default_target());
int thread_count = options.thread_count_middle();
if (thread_count == 0)
thread_count = std::max(2, input_objects->number_of_input_objects());
workqueue->set_thread_count(thread_count);
// Now we have seen all the input files.
const bool doing_static_link = (!input_objects->any_dynamic()
&& !parameters->options().shared());
set_parameters_doing_static_link(doing_static_link);
if (!doing_static_link && options.is_static())
{
// We print out just the first .so we see; there may be others.
gold_error(_("cannot mix -static with dynamic object %s"),
(*input_objects->dynobj_begin())->name().c_str());
}
if (!doing_static_link && parameters->options().relocatable())
gold_error(_("cannot mix -r with dynamic object %s"),
(*input_objects->dynobj_begin())->name().c_str());
if (!doing_static_link
&& options.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
gold_fatal(_("cannot use non-ELF output format with dynamic object %s"),
(*input_objects->dynobj_begin())->name().c_str());
if (is_debugging_enabled(DEBUG_SCRIPT))
layout->script_options()->print(stderr);
// For each dynamic object, record whether we've seen all the
// dynamic objects that it depends upon.
input_objects->check_dynamic_dependencies();
// See if any of the input definitions violate the One Definition Rule.
// TODO: if this is too slow, do this as a task, rather than inline.
symtab->detect_odr_violations(task, options.output_file_name());
// Create any output sections required by any linker script.
layout->create_script_sections();
// Define some sections and symbols needed for a dynamic link. This
// handles some cases we want to see before we read the relocs.
layout->create_initial_dynamic_sections(symtab);
// Define symbols from any linker scripts.
layout->define_script_symbols(symtab);
// Attach sections to segments.
layout->attach_sections_to_segments();
if (!parameters->options().relocatable())
{
// Predefine standard symbols.
define_standard_symbols(symtab, layout);
// Define __start and __stop symbols for output sections where
// appropriate.
layout->define_section_symbols(symtab);
}
// Make sure we have symbols for any required group signatures.
layout->define_group_signatures(symtab);
// Read the relocations of the input files. We do this to find
// which symbols are used by relocations which require a GOT and/or
// a PLT entry, or a COPY reloc. When we implement garbage
// collection we will do it here by reading the relocations in a
// breadth first search by references.
//
// We could also read the relocations during the first pass, and
// mark symbols at that time. That is how the old GNU linker works.
// Doing that is more complex, since we may later decide to discard
// some of the sections, and thus change our minds about the types
// of references made to the symbols.
Task_token* blocker = new Task_token(true);
Task_token* symtab_lock = new Task_token(false);
for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
p != input_objects->relobj_end();
++p)
{
// We can read and process the relocations in any order. But we
// only want one task to write to the symbol table at a time.
// So we queue up a task for each object to read the
// relocations. That task will in turn queue a task to wait
// until it can write to the symbol table.
blocker->add_blocker();
workqueue->queue(new Read_relocs(options, symtab, layout, *p,
symtab_lock, blocker));
}
// Allocate common symbols. This requires write access to the
// symbol table, but is independent of the relocation processing.
if (parameters->options().define_common())
{
blocker->add_blocker();
workqueue->queue(new Allocate_commons_task(symtab, layout, symtab_lock,
blocker));
}
// When all those tasks are complete, we can start laying out the
// output file.
// TODO(csilvers): figure out a more principled way to get the target
Target* target = const_cast<Target*>(&parameters->target());
workqueue->queue(new Task_function(new Layout_task_runner(options,
input_objects,
symtab,
target,
layout),
blocker,
"Task_function Layout_task_runner"));
}
// Queue up the final set of tasks. This is called at the end of
// Layout_task.
void
queue_final_tasks(const General_options& options,
const Input_objects* input_objects,
const Symbol_table* symtab,
Layout* layout,
Workqueue* workqueue,
Output_file* of)
{
int thread_count = options.thread_count_final();
if (thread_count == 0)
thread_count = std::max(2, input_objects->number_of_input_objects());
workqueue->set_thread_count(thread_count);
bool any_postprocessing_sections = layout->any_postprocessing_sections();
// Use a blocker to wait until all the input sections have been
// written out.
Task_token* input_sections_blocker = NULL;
if (!any_postprocessing_sections)
input_sections_blocker = new Task_token(true);
// Use a blocker to block any objects which have to wait for the
// output sections to complete before they can apply relocations.
Task_token* output_sections_blocker = new Task_token(true);
// Use a blocker to block the final cleanup task.
Task_token* final_blocker = new Task_token(true);
// Queue a task to write out the symbol table.
final_blocker->add_blocker();
workqueue->queue(new Write_symbols_task(layout,
symtab,
input_objects,
layout->sympool(),
layout->dynpool(),
of,
final_blocker));
// Queue a task to write out the output sections.
output_sections_blocker->add_blocker();
final_blocker->add_blocker();
workqueue->queue(new Write_sections_task(layout, of, output_sections_blocker,
final_blocker));
// Queue a task to write out everything else.
final_blocker->add_blocker();
workqueue->queue(new Write_data_task(layout, symtab, of, final_blocker));
// Queue a task for each input object to relocate the sections and
// write out the local symbols.
for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
p != input_objects->relobj_end();
++p)
{
if (input_sections_blocker != NULL)
input_sections_blocker->add_blocker();
final_blocker->add_blocker();
workqueue->queue(new Relocate_task(options, symtab, layout, *p, of,
input_sections_blocker,
output_sections_blocker,
final_blocker));
}
// Queue a task to write out the output sections which depend on
// input sections. If there are any sections which require
// postprocessing, then we need to do this last, since it may resize
// the output file.
if (!any_postprocessing_sections)
{
final_blocker->add_blocker();
Task* t = new Write_after_input_sections_task(layout, of,
input_sections_blocker,
final_blocker);
workqueue->queue(t);
}
else
{
Task_token *new_final_blocker = new Task_token(true);
new_final_blocker->add_blocker();
Task* t = new Write_after_input_sections_task(layout, of,
final_blocker,
new_final_blocker);
workqueue->queue(t);
final_blocker = new_final_blocker;
}
// Queue a task to close the output file. This will be blocked by
// FINAL_BLOCKER.
workqueue->queue(new Task_function(new Close_task_runner(&options, layout,
of),
final_blocker,
"Task_function Close_task_runner"));
}
} // End namespace gold.