2009-01-20 Sriraman Tallam <tmsriram@google.com>

	* 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.

1 files changed, 8 insertions, 1 deletions

diff --git a/gold/main.cc b/gold/main.cc
index 8e8e8f9..0019863 100644
--- a/gold/main.cc
+++ b/gold/main.cc
@@ -1,6 +1,6 @@
 // main.cc -- gold main function.
 
-// 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.
@@ -43,6 +43,7 @@
 #include "symtab.h"
 #include "layout.h"
 #include "plugin.h"
+#include "gc.h"
 
 using namespace gold;
 
@@ -201,6 +202,9 @@ main(int argc, char** argv)
   // The list of input objects.
   Input_objects input_objects;
 
+  // The Garbage Collection Object.
+  Garbage_collection gc;
+
   // The symbol table.  We're going to guess here how many symbols
   // we're going to see based on the number of input files.  Even when
   // this is off, it means at worst we don't quite optimize hashtable
@@ -208,6 +212,9 @@ main(int argc, char** argv)
   Symbol_table symtab(command_line.number_of_input_files() * 1024,
                       command_line.version_script());
 
+  if (parameters->options().gc_sections())
+    symtab.set_gc(&gc);
+
   // The layout object.
   Layout layout(command_line.options(), &command_line.script_options());