/*
 * Copyright (c) 2002-2004 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Nathan Binkert
 *          Steve Reinhardt
 */

#ifndef __BASE_LOADER_OBJECT_FILE_HH__
#define __BASE_LOADER_OBJECT_FILE_HH__

#include <string>

#include "base/loader/image_file.hh"
#include "base/loader/image_file_data.hh"
#include "base/loader/memory_image.hh"
#include "base/logging.hh"
#include "base/types.hh"

class Process;
class ProcessParams;
class SymbolTable;

class ObjectFile : public ImageFile
{
  public:

    enum Arch {
        UnknownArch,
        Alpha,
        SPARC64,
        SPARC32,
        Mips,
        X86_64,
        I386,
        Arm64,
        Arm,
        Thumb,
        Power,
        Riscv64,
        Riscv32
    };

    enum OpSys {
        UnknownOpSys,
        Tru64,
        Linux,
        Solaris,
        LinuxArmOABI,
        FreeBSD
    };

  protected:
    Arch arch = UnknownArch;
    OpSys opSys = UnknownOpSys;

    ObjectFile(ImageFileDataPtr ifd);

  public:
    virtual ~ObjectFile() {};

    virtual bool
    loadAllSymbols(SymbolTable *symtab, Addr base=0,
            Addr offset=0, Addr mask=MaxAddr)
    {
        return true;
    };
    virtual bool
    loadGlobalSymbols(SymbolTable *symtab, Addr base=0,
                      Addr offset=0, Addr mask=MaxAddr)
    {
        return true;
    }
    virtual bool
    loadLocalSymbols(SymbolTable *symtab, Addr base=0,
                     Addr offset=0, Addr mask=MaxAddr)
    {
        return true;
    }
    virtual bool
    loadWeakSymbols(SymbolTable *symtab, Addr base=0,
                    Addr offset=0, Addr mask=MaxAddr)
    {
        return true;
    }

    virtual ObjectFile *getInterpreter() const { return nullptr; }
    virtual bool relocatable() const { return false; }
    virtual Addr
    mapSize() const
    {
        panic("mapSize() should only be called on relocatable objects\n");
    }
    virtual void
    updateBias(Addr bias_addr)
    {
        panic("updateBias() should only be called on relocatable objects\n");
    }
    virtual Addr bias() const { return 0; }

    virtual bool hasTLS() { return false; }

    Arch  getArch()  const { return arch; }
    OpSys getOpSys() const { return opSys; }

  protected:
    Addr entry = 0;

  public:
    Addr entryPoint() const { return entry; }

    /**
     * Each instance of a Loader subclass will have a chance to try to load
     * an object file when tryLoaders is called. If they can't because they
     * aren't compatible with it (wrong arch, wrong OS, etc), then they
     * silently fail by returning nullptr so other loaders can try.
     */
    class Loader
    {
      public:
        Loader();

        /* Loader instances are singletons. */
        Loader(const Loader &) = delete;
        void operator=(const Loader &) = delete;

        virtual ~Loader() {}

        /**
         * Each subclass needs to implement this method. If the loader is
         * compatible with the passed in object file, it should return the
         * created Process object corresponding to it. If not, it should fail
         * silently and return nullptr. If there's a non-compatibliity related
         * error like file IO errors, etc., those should fail non-silently
         * with a panic or fail as normal.
         */
        virtual Process *load(ProcessParams *params, ObjectFile *obj_file) = 0;
    };

    // Try all the Loader instance's "load" methods one by one until one is
    // successful. If none are, complain and fail.
    static Process *tryLoaders(ProcessParams *params, ObjectFile *obj_file);
};

class ObjectFileFormat
{
  protected:
    ObjectFileFormat();

  public:
    ObjectFileFormat(const ObjectFileFormat &) = delete;
    void operator=(const ObjectFileFormat &) = delete;

    virtual ObjectFile *load(ImageFileDataPtr data) = 0;
};

ObjectFile *createObjectFile(const std::string &fname, bool raw=false);

#endif // __BASE_LOADER_OBJECT_FILE_HH__