/*

 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef SHARE_VM_RUNTIME_STUBCODEGENERATOR_HPP

#define SHARE_VM_RUNTIME_STUBCODEGENERATOR_HPP

#include "asm/assembler.hpp"

#include "memory/allocation.hpp"

// All the basic framework for stub code generation/debugging/printing.

// A StubCodeDesc describes a piece of generated code (usually stubs).

// This information is mainly useful for debugging and printing.

// Currently, code descriptors are simply chained in a linked list,

// this may have to change if searching becomes too slow.

class StubCodeDesc: public CHeapObj<mtCode> {

 private:

  static StubCodeDesc* _list;                  // the list of all descriptors

  static bool          _frozen;                // determines whether _list modifications are allowed

  StubCodeDesc*        _next;                  // the next element in the linked list

  const char*          _group;                 // the group to which the stub code belongs

  const char*          _name;                  // the name assigned to the stub code

  address              _begin;                 // points to the first byte of the stub code    (included)

  address              _end;                   // points to the first byte after the stub code (excluded)

  void set_end(address end) {

    assert(_begin <= end, "begin & end not properly ordered");

    _end = end;

  }

  void set_begin(address begin) {

    assert(begin >= _begin, "begin may not decrease");

    assert(_end == NULL || begin <= _end, "begin & end not properly ordered");

    _begin = begin;

  }

  friend class StubCodeMark;

  friend class StubCodeGenerator;

 public:

  static StubCodeDesc* first() { return _list; }

  static StubCodeDesc* next(StubCodeDesc* desc)  { return desc->_next; }

  static StubCodeDesc* desc_for(address pc);     // returns the code descriptor for the code containing pc or NULL

  static const char*   name_for(address pc);     // returns the name of the code containing pc or NULL

  StubCodeDesc(const char* group, const char* name, address begin, address end = NULL) {

    assert(!_frozen, "no modifications allowed");

    assert(name != NULL, "no name specified");

    _next           = _list;

    _group          = group;

    _name           = name;

    _begin          = begin;

    _end            = end;

    _list           = this;

  };

  static void freeze();

  const char* group() const                      { return _group; }

  const char* name() const                       { return _name; }

  address     begin() const                      { return _begin; }

  address     end() const                        { return _end; }

  int         size_in_bytes() const              { return _end - _begin; }

  bool        contains(address pc) const         { return _begin <= pc && pc < _end; }

  void        print_on(outputStream* st) const;

  void        print() const                      { print_on(tty); }

};

// The base class for all stub-generating code generators.

// Provides utility functions.

class StubCodeGenerator: public StackObj {

 private:

  bool _print_code;

 protected:

  MacroAssembler*  _masm;

 public:

  StubCodeGenerator(CodeBuffer* code, bool print_code = false);

  ~StubCodeGenerator();

  MacroAssembler* assembler() const              { return _masm; }

  virtual void stub_prolog(StubCodeDesc* cdesc); // called by StubCodeMark constructor

  virtual void stub_epilog(StubCodeDesc* cdesc); // called by StubCodeMark destructor

};

// Stack-allocated helper class used to associate a stub code with a name.

// All stub code generating functions that use a StubCodeMark will be registered

// in the global StubCodeDesc list and the generated stub code can be identified

// later via an address pointing into it.

class StubCodeMark: public StackObj {

 private:

  StubCodeGenerator* _cgen;

  StubCodeDesc*      _cdesc;

 public:

  StubCodeMark(StubCodeGenerator* cgen, const char* group, const char* name);

  ~StubCodeMark();

};

#endif // SHARE_VM_RUNTIME_STUBCODEGENERATOR_HPP