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authorSriraman Tallam <tmsriram@google.com>2009-01-28 02:25:33 +0000
committerSriraman Tallam <tmsriram@google.com>2009-01-28 02:25:33 +0000
commit6d03d481a0827abf92804f8ffaf9ab00593943be (patch)
tree617f1054036bd3cca35f897b225b37b4ce1a3b0c /gold/object.h
parent7df3ce47694f5c804a9468d4c098825b5901216e (diff)
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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.
Diffstat (limited to 'gold/object.h')
-rw-r--r--gold/object.h68
1 files changed, 67 insertions, 1 deletions
diff --git a/gold/object.h b/gold/object.h
index 6c8c7a3..614a02e 100644
--- a/gold/object.h
+++ b/gold/object.h
@@ -1,6 +1,6 @@
// object.h -- support for an object file for linking in gold -*- C++ -*-
-// 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.
@@ -46,6 +46,7 @@ class Pluginobj;
class Dynobj;
class Object_merge_map;
class Relocatable_relocs;
+class Symbols_data;
template<typename Stringpool_char>
class Stringpool_template;
@@ -598,11 +599,52 @@ class Relobj : public Object
relocs_must_follow_section_writes_(false)
{ }
+ // During garbage collection, the Read_symbols_data pass for
+ // each object is stored as layout needs to be done after
+ // reloc processing.
+ Symbols_data*
+ get_symbols_data()
+ { return this->sd_; }
+
+ // Decides which section names have to be included in the worklist
+ // as roots.
+ bool
+ is_section_name_included(const char *name);
+
+ void
+ copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
+ unsigned int section_header_size);
+
+ void
+ set_symbols_data(Symbols_data* sd)
+ { this->sd_ = sd; }
+
+ // During garbage collection, the Read_relocs pass for all objects
+ // is done before scanning the relocs. In that case, this->rd_ is
+ // used to store the information from Read_relocs for each object.
+ // This data is also used to compute the list of relevant sections.
+ Read_relocs_data*
+ get_relocs_data()
+ { return this->rd_; }
+
+ void
+ set_relocs_data(Read_relocs_data* rd)
+ { this->rd_ = rd; }
+
+ virtual bool
+ is_output_section_offset_invalid(unsigned int shndx) const = 0;
+
// Read the relocs.
void
read_relocs(Read_relocs_data* rd)
{ return this->do_read_relocs(rd); }
+ // Process the relocs, during garbage collection only.
+ void
+ gc_process_relocs(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Read_relocs_data* rd)
+ { return this->do_gc_process_relocs(options, symtab, layout, rd); }
+
// Scan the relocs and adjust the symbol table.
void
scan_relocs(const General_options& options, Symbol_table* symtab,
@@ -728,6 +770,11 @@ class Relobj : public Object
virtual void
do_read_relocs(Read_relocs_data*) = 0;
+ // Process the relocs--implemented by child class.
+ virtual void
+ do_gc_process_relocs(const General_options&, Symbol_table*, Layout*,
+ Read_relocs_data*) = 0;
+
// Scan the relocs--implemented by child class.
virtual void
do_scan_relocs(const General_options&, Symbol_table*, Layout*,
@@ -810,6 +857,13 @@ class Relobj : public Object
// Whether we need to wait for output sections to be written before
// we can apply relocations.
bool relocs_must_follow_section_writes_;
+ // Used to store the relocs data computed by the Read_relocs pass.
+ // Used during garbage collection of unused sections.
+ Read_relocs_data* rd_;
+ // Used to store the symbols data computed by the Read_symbols pass.
+ // Again used during garbage collection when laying out referenced
+ // sections.
+ gold::Symbols_data *sd_;
};
// This class is used to handle relocations against a section symbol
@@ -1220,6 +1274,12 @@ class Sized_relobj : public Relobj
~Sized_relobj();
+ // Checks if the offset of input section SHNDX within its output
+ // section is invalid.
+ bool
+ is_output_section_offset_invalid(unsigned int shndx) const
+ { return this->get_output_section_offset(shndx) == invalid_address; }
+
// Set up the object file based on the ELF header.
void
setup(const typename elfcpp::Ehdr<size, big_endian>&);
@@ -1392,6 +1452,12 @@ class Sized_relobj : public Relobj
void
do_read_relocs(Read_relocs_data*);
+ // Process the relocs to find list of referenced sections. Used only
+ // during garbage collection.
+ void
+ do_gc_process_relocs(const General_options&, Symbol_table*, Layout*,
+ Read_relocs_data*);
+
// Scan the relocs and adjust the symbol table.
void
do_scan_relocs(const General_options&, Symbol_table*, Layout*,