upload android base code part8

android/toolchain/binutils/binutils-2.25/gold/target-select.h

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+// target-select.h -- select a target for an object file  -*- C++ -*-
+
+// Copyright (C) 2006-2014 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.
+
+#ifndef GOLD_TARGET_SELECT_H
+#define GOLD_TARGET_SELECT_H
+
+#include <vector>
+
+#include "gold-threads.h"
+
+namespace gold
+{
+
+class Input_file;
+class Target;
+class Target_selector;
+
+// Used to set the target only once.
+
+class Set_target_once : public Once
+{
+ public:
+  Set_target_once(Target_selector* target_selector)
+    : target_selector_(target_selector)
+  { }
+
+ protected:
+  void
+  do_run_once(void*);
+
+ private:
+  Target_selector* target_selector_;
+};
+
+// We want to avoid a master list of targets, which implies using a
+// global constructor.  And we also want the program to start up as
+// quickly as possible, which implies avoiding global constructors.
+// We compromise on a very simple global constructor.  We use a target
+// selector, which specifies an ELF machine number and a recognition
+// function.  We use global constructors to build a linked list of
+// target selectors--a simple pointer list, not a std::list.
+
+class Target_selector
+{
+ public:
+  // Create a target selector for a specific machine number, size (32
+  // or 64), and endianness.  The machine number can be EM_NONE to
+  // test for any machine number.  BFD_NAME is the name of the target
+  // used by the GNU linker, for backward compatibility; it may be
+  // NULL.  EMULATION is the name of the emulation used by the GNU
+  // linker; it is similar to BFD_NAME.
+  Target_selector(int machine, int size, bool is_big_endian,
+		  const char* bfd_name, const char* emulation);
+
+  virtual ~Target_selector()
+  { }
+
+  // If we can handle this target, return a pointer to a target
+  // structure.  The size and endianness are known.
+  Target*
+  recognize(Input_file* input_file, off_t offset,
+	    int machine, int osabi, int abiversion)
+  { return this->do_recognize(input_file, offset, machine, osabi, abiversion); }
+
+  // If NAME matches the target, return a pointer to a target
+  // structure.
+  Target*
+  recognize_by_bfd_name(const char* name)
+  { return this->do_recognize_by_bfd_name(name); }
+
+  // Push all supported BFD names onto the vector.  This is only used
+  // for help output.
+  void
+  supported_bfd_names(std::vector<const char*>* names)
+  { this->do_supported_bfd_names(names); }
+
+  // If NAME matches the target emulation, return a pointer to a
+  // target structure.
+  Target*
+  recognize_by_emulation(const char* name)
+  { return this->do_recognize_by_emulation(name); }
+
+  // Push all supported emulations onto the vector.  This is only used
+  // for help output.
+  void
+  supported_emulations(std::vector<const char*>* names)
+  { this->do_supported_emulations(names); }
+
+  // Return the next Target_selector in the linked list.
+  Target_selector*
+  next() const
+  { return this->next_; }
+
+  // Return the machine number this selector is looking for.  This can
+  // be EM_NONE to match any machine number, in which case the
+  // do_recognize hook will be responsible for matching the machine
+  // number.
+  int
+  machine() const
+  { return this->machine_; }
+
+  // Return the size this is looking for (32 or 64).
+  int
+  get_size() const
+  { return this->size_; }
+
+  // Return the endianness this is looking for.
+  bool
+  is_big_endian() const
+  { return this->is_big_endian_; }
+
+  // Return the BFD name.  This may return NULL, in which case the
+  // do_recognize_by_bfd_name hook will be responsible for matching
+  // the BFD name.
+  const char*
+  bfd_name() const
+  { return this->bfd_name_; }
+
+  // Return the emulation.  This may return NULL, in which case the
+  // do_recognize_by_emulation hook will be responsible for matching
+  // the emulation.
+  const char*
+  emulation() const
+  { return this->emulation_; }
+
+  // The reverse mapping, for --print-output-format: if we
+  // instantiated TARGET, return our BFD_NAME.  If we did not
+  // instantiate it, return NULL.
+  const char*
+  target_bfd_name(const Target* target)
+  { return this->do_target_bfd_name(target); }
+
+ protected:
+  // Return an instance of the real target.  This must be implemented
+  // by the child class.
+  virtual Target*
+  do_instantiate_target() = 0;
+
+  // Recognize an object file given a machine code, OSABI code, and
+  // ELF version value.  When this is called we already know that they
+  // match the machine_, size_, and is_big_endian_ fields.  The child
+  // class may implement a different version of this to do additional
+  // checks, or to check for multiple machine codes if the machine_
+  // field is EM_NONE.
+  virtual Target*
+  do_recognize(Input_file*, off_t, int, int, int)
+  { return this->instantiate_target(); }
+
+  // Recognize a target by name.  When this is called we already know
+  // that the name matches (or that the bfd_name_ field is NULL).  The
+  // child class may implement a different version of this to
+  // recognize more than one name.
+  virtual Target*
+  do_recognize_by_bfd_name(const char*)
+  { return this->instantiate_target(); }
+
+  // Return a list of supported BFD names.  The child class may
+  // implement a different version of this to handle more than one
+  // name.
+  virtual void
+  do_supported_bfd_names(std::vector<const char*>* names)
+  {
+    gold_assert(this->bfd_name_ != NULL);
+    names->push_back(this->bfd_name_);
+  }
+
+  // Recognize a target by emulation.  When this is called we already
+  // know that the name matches (or that the emulation_ field is
+  // NULL).  The child class may implement a different version of this
+  // to recognize more than one emulation.
+  virtual Target*
+  do_recognize_by_emulation(const char*)
+  { return this->instantiate_target(); }
+
+  // Return a list of supported emulations.  The child class may
+  // implement a different version of this to handle more than one
+  // emulation.
+  virtual void
+  do_supported_emulations(std::vector<const char*>* emulations)
+  {
+    gold_assert(this->emulation_ != NULL);
+    emulations->push_back(this->emulation_);
+  }
+
+  // Map from target to BFD name.
+  virtual const char*
+  do_target_bfd_name(const Target*);
+
+  // Instantiate the target and return it.
+  Target*
+  instantiate_target();
+
+  // Return whether TARGET is the target we instantiated.
+  bool
+  is_our_target(const Target* target)
+  { return target == this->instantiated_target_; }
+
+ private:
+  // Set the target.
+  void
+  set_target();
+
+  friend class Set_target_once;
+
+  // ELF machine code.
+  const int machine_;
+  // Target size--32 or 64.
+  const int size_;
+  // Whether the target is big endian.
+  const bool is_big_endian_;
+  // BFD name of target, for compatibility.
+  const char* const bfd_name_;
+  // GNU linker emulation for this target, for compatibility.
+  const char* const emulation_;
+  // Next entry in list built at global constructor time.
+  Target_selector* next_;
+  // The singleton Target structure--this points to an instance of the
+  // real implementation.
+  Target* instantiated_target_;
+  // Used to set the target only once.
+  Set_target_once set_target_once_;
+};
+
+// Select the target for an ELF file.
+
+extern Target*
+select_target(Input_file*, off_t,
+	      int machine, int size, bool big_endian, int osabi,
+	      int abiversion);
+
+// Select a target using a BFD name.
+
+extern Target*
+select_target_by_bfd_name(const char* name);
+
+// Select a target using a GNU linker emulation.
+
+extern Target*
+select_target_by_emulation(const char* name);
+
+// Fill in a vector with the list of supported targets.  This returns
+// a list of BFD names.
+
+extern void
+supported_target_names(std::vector<const char*>*);
+
+// Fill in a vector with the list of supported emulations.
+
+extern void
+supported_emulation_names(std::vector<const char*>*);
+
+// Print the output format, for the --print-output-format option.
+
+extern void
+print_output_format();
+
+} // End namespace gold.
+
+#endif // !defined(GOLD_TARGET_SELECT_H)