Merge commit 'upstream/2.20'

[msp430-binutils.git] / gold / icf.h

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+// icf.h --  Identical Code Folding
+
+// Copyright 2009 Free Software Foundation, Inc.
+// Written by Sriraman Tallam <tmsriram@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.
+
+#ifndef GOLD_ICF_H
+#define GOLD_ICF_H
+
+#include <vector>
+
+#include "elfcpp.h"
+#include "symtab.h"
+
+namespace gold
+{
+
+class Object;
+class Input_objects;
+class Symbol_table;
+
+typedef std::pair<Object*, unsigned int> Section_id;
+
+class Icf
+{
+ public:
+  struct Section_id_hash
+  {
+    size_t operator()(const Section_id& loc) const
+    { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; }
+  };
+
+  typedef std::vector<Section_id> Sections_reachable_list;
+  typedef std::vector<Symbol*> Symbol_info;
+  typedef std::vector<std::pair<long long, long long> > Addend_info;
+  typedef Unordered_map<Section_id,
+                        Sections_reachable_list,
+                        Section_id_hash> Section_list;
+  typedef Unordered_map<Section_id, Symbol_info, Section_id_hash> Symbol_list;
+  typedef Unordered_map<Section_id, Addend_info, Section_id_hash> Addend_list;
+  typedef Unordered_map<Section_id,
+                        unsigned int,
+                        Section_id_hash> Uniq_secn_id_map;
+
+  Icf()
+  : id_section_(), section_id_(), kept_section_id_(),
+    num_tracked_relocs(NULL), icf_ready_(false),
+    section_reloc_list_(), symbol_reloc_list_(),
+    addend_reloc_list_()
+  { }
+
+  // Returns the kept folded identical section corresponding to
+  // dup_obj and dup_shndx.
+  Section_id
+  get_folded_section(Object* dup_obj, unsigned int dup_shndx);
+
+  // Forms groups of identical sections where the first member
+  // of each group is the kept section during folding.
+  void
+  find_identical_sections(const Input_objects* input_objects,
+                          Symbol_table* symtab);
+
+  // This is set when ICF has been run and the groups of
+  // identical sections have been formed.
+  void
+  icf_ready()
+  { this->icf_ready_ = true; }
+
+  // Returns true if ICF has been run.
+  bool
+  is_icf_ready()
+  { return this->icf_ready_; }
+
+  // Unfolds the section denoted by OBJ and SHNDX if folded.
+  void
+  unfold_section(Object* obj, unsigned int shndx);
+
+  // Returns the kept section corresponding to the 
+  // given section.
+  bool
+  is_section_folded(Object* obj, unsigned int shndx);
+    
+  // Returns a map of a section to a list of all sections referenced
+  // by its relocations.
+  Section_list&
+  section_reloc_list()
+  { return this->section_reloc_list_; }
+
+  // Returns a map of  a section to a list of all symbols referenced
+  // by its relocations.
+  Symbol_list&
+  symbol_reloc_list()
+  { return this->symbol_reloc_list_; }
+
+  // Returns a maps of a section to a list of symbol values and addends
+  // of its relocations.
+  Addend_list&
+  addend_reloc_list()
+  { return this->addend_reloc_list_; }
+  
+  // Returns a mapping of each section to a unique integer.
+  Uniq_secn_id_map&
+  section_to_int_map()
+  { return this->section_id_; }
+
+ private:
+
+  // Maps integers to sections.
+  std::vector<Section_id> id_section_;
+  // Does the reverse.
+  Uniq_secn_id_map section_id_;
+  // Given a section id, this maps it to the id of the kept
+  // section.  If the id's are the same then this section is
+  // not folded.
+  std::vector<unsigned int> kept_section_id_;
+  unsigned int* num_tracked_relocs;
+  // Flag to indicate if ICF has been run.
+  bool icf_ready_;
+
+  // These lists are populated by gc_process_relocs in gc.h.
+  Section_list section_reloc_list_;
+  Symbol_list symbol_reloc_list_;
+  Addend_list addend_reloc_list_;
+};
+
+} // End of namespace gold.
+
+#endif