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* Makefile.am (CCFILES): Add gc.cc. (HFILES): Add gc.h. * Makefile.in: Regenerate. * gold.cc (Gc_runner): New class. (queue_initial_tasks): Call garbage collection related tasks when corresponding options are invoked. (queue_middle_gc_tasks): New function. (queue_middle_tasks): Reorder tasks to allow relocs to be read and processed early before laying out sections during garbage collection. * gold.h (queue_middle_gc_tasks): New function. (is_prefix_of): Move from "layout.cc". * i386.cc (Target_i386::gc_process_relocs): New function. * layout.cc (is_prefix_of): Remove. Move to "gold.h" * main.cc (main): Create object of class "Garbage_collection". * object.cc (Relobj::copy_symbols_data): New function. (Relobj::is_section_name_included): New function. (Sized_relobj::do_layout): Allow this function to be called twice during garbage collection and defer layout of section during the first call. * object.h (Relobj::get_symbols_data): New function. (Relobj::is_section_name_included): New function. (Relobj::copy_symbols_data): New function. (Relobj::set_symbols_data): New function. (Relobj::get_relocs_data): New function. (Relobj::set_relocs_data): New function. (Relobj::is_output_section_offset_invalid): New pure virtual function. (Relobj::gc_process_relocs): New function. (Relobj::do_gc_process_relocs): New pure virtual function. (Relobj::sd_): New data member. (Sized_relobj::is_output_section_offset_invalid): New function. (Sized_relobj::do_gc_process_relocs): New function. * options.h (General_options::gc_sections): Modify to not be a no-op. (General_options::print_gc_sections): New option. * plugin.cc (Plugin_finish::run): Remove function call to Plugin_manager::layout_deferred_objects. Move it to "gold.cc". * powerpc.cc (Target_powerpc::gc_process_relocs): New function. * reloc.cc (Read_relocs::run): Add task to process relocs and determine unreferenced sections when doing garbage collection. (Gc_process_relocs): New class. (Sized_relobj::do_gc_process_relocs): New function. (Sized_relobj::do_scan_relocs): Don't try to scan the relocs for sections that are garbage collected. * reloc.h (Gc_process_relocs): New class. * sparc.cc (Target_sparc::gc_process_relocs): New function. * symtab.cc (Symbol::should_add_dynsym_entry): Do not add entries for symbols whose corresponding sections are garbage collected. (Symbol_table::Symbol_table): Add new parameter for the garbage collection object. (Symbol_table::gc_mark_undef_symbols): New function. (Symbol_table::gc_mark_symbol_for_shlib): New function. (Symbol_table::gc_mark_dyn_syms): New function. (Symbol_table::resolve): Do not treat symbols seen in dynamic objects as garbage. (Symbol_table::add_from_object): Likewise. (Symbol_table::add_from_relobj): When building shared objects, do not treat externally visible symbols as garbage. (Symbol_table::sized_finalize_symbol): Do not check dynamic symbol table information for static and relocatable links. * symtab.h (Symbol_table::set_gc): New function. (Symbol_table::gc): New function. (Symbol_table::gc_mark_undef_symbols): New function. (Symbol_table::gc_mark_symbol_for_shlib): New function. (Symbol_table::gc_mark_dyn_syms): New function. (Symbol_table::gc_): New data member. * target.h (Sized_target::gc_process_relocs): New pure virtual function. * x86_64.cc (Target_x86_64::gc_process_relocs): New function. * testsuite/testfile.cc (Target_test::gc_process_relocs): New function.
75 lines
2.3 KiB
C++
75 lines
2.3 KiB
C++
// gc.cc -- garbage collection of unused sections
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// Copyright 2009 Free Software Foundation, Inc.
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// Written by Sriraman Tallam <tmsriram@google.com>.
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// This file is part of gold.
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 3 of the License, or
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// (at your option) any later version.
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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// MA 02110-1301, USA.
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#include "gold.h"
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#include "object.h"
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#include "gc.h"
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#include "symtab.h"
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namespace gold
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{
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// Garbage collection uses a worklist style algorithm to determine the
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// transitive closure of all referenced sections.
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void
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Garbage_collection::do_transitive_closure()
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{
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while (!this->worklist().empty())
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{
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// Add elements from the work list to the referenced list
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// one by one.
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Section_id entry = this->worklist().front();
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this->worklist().pop();
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if (this->referenced_list().find(entry)
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== this->referenced_list().end())
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{
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this->referenced_list().insert(entry);
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}
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else
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{
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continue;
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}
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Garbage_collection::Section_ref::iterator find_it =
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this->section_reloc_map().find(entry);
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if (find_it == this->section_reloc_map().end())
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continue;
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Garbage_collection::Sections_reachable v = find_it->second;
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// Scan the vector of references for each work_list entry.
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for (Garbage_collection::Sections_reachable::iterator it_v = v.begin();
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it_v != v.end();
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++it_v)
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{
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// Do not add already processed sections to the work_list.
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if (this->referenced_list().find(*it_v)
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== this->referenced_list().end())
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{
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this->worklist().push(*it_v);
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}
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}
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}
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this->worklist_ready();
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}
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} // End namespace gold.
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