/*

 * Copyright 1999-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

#include "incls/_precompiled.incl"

#include "incls/_ciInstanceKlass.cpp.incl"

// ciInstanceKlass

//

// This class represents a klassOop in the HotSpot virtual machine

// whose Klass part in an instanceKlass.

// ------------------------------------------------------------------

// ciInstanceKlass::ciInstanceKlass

//

// Loaded instance klass.

ciInstanceKlass::ciInstanceKlass(KlassHandle h_k) : ciKlass(h_k) {

  assert(get_Klass()->oop_is_instance(), "wrong type");

  instanceKlass* ik = get_instanceKlass();

  AccessFlags access_flags = ik->access_flags();

  _flags = ciFlags(access_flags);

  _has_finalizer = access_flags.has_finalizer();

  _has_subklass = ik->subklass() != NULL;

  _is_initialized = ik->is_initialized();

  // Next line must follow and use the result of the previous line:

  _is_linked = _is_initialized || ik->is_linked();

  _nonstatic_field_size = ik->nonstatic_field_size();

  _nonstatic_fields = NULL; // initialized lazily by compute_nonstatic_fields:

  _nof_implementors = ik->nof_implementors();

  for (int i = 0; i < implementors_limit; i++) {

    _implementors[i] = NULL;  // we will fill these lazily

  }

  Thread *thread = Thread::current();

  if (ciObjectFactory::is_initialized()) {

    _loader = JNIHandles::make_local(thread, ik->class_loader());

    _protection_domain = JNIHandles::make_local(thread,

                                                ik->protection_domain());

    _is_shared = false;

  } else {

    Handle h_loader(thread, ik->class_loader());

    Handle h_protection_domain(thread, ik->protection_domain());

    _loader = JNIHandles::make_global(h_loader);

    _protection_domain = JNIHandles::make_global(h_protection_domain);

    _is_shared = true;

  }

  // Lazy fields get filled in only upon request.

  _super  = NULL;

  _java_mirror = NULL;

  if (is_shared()) {

    if (h_k() != SystemDictionary::object_klass()) {

      super();

    }

    java_mirror();

    //compute_nonstatic_fields();  // done outside of constructor

  }

  _field_cache = NULL;

}

// Version for unloaded classes:

ciInstanceKlass::ciInstanceKlass(ciSymbol* name,

                                 jobject loader, jobject protection_domain)

  : ciKlass(name, ciInstanceKlassKlass::make())

{

  assert(name->byte_at(0) != '[', "not an instance klass");

  _is_initialized = false;

  _is_linked = false;

  _nonstatic_field_size = -1;

  _nonstatic_fields = NULL;

  _nof_implementors = -1;

  _loader = loader;

  _protection_domain = protection_domain;

  _is_shared = false;

  _super = NULL;

  _java_mirror = NULL;

  _field_cache = NULL;

}

// ------------------------------------------------------------------

// ciInstanceKlass::compute_shared_is_initialized

bool ciInstanceKlass::compute_shared_is_initialized() {

  GUARDED_VM_ENTRY(

    instanceKlass* ik = get_instanceKlass();

    _is_initialized = ik->is_initialized();

    return _is_initialized;

  )

}

// ------------------------------------------------------------------

// ciInstanceKlass::compute_shared_is_linked

bool ciInstanceKlass::compute_shared_is_linked() {

  GUARDED_VM_ENTRY(

    instanceKlass* ik = get_instanceKlass();

    _is_linked = ik->is_linked();

    return _is_linked;

  )

}

// ------------------------------------------------------------------

// ciInstanceKlass::compute_shared_has_subklass

bool ciInstanceKlass::compute_shared_has_subklass() {

  GUARDED_VM_ENTRY(

    instanceKlass* ik = get_instanceKlass();

    _has_subklass = ik->subklass() != NULL;

    return _has_subklass;

  )

}

// ------------------------------------------------------------------

// ciInstanceKlass::compute_shared_nof_implementors

int ciInstanceKlass::compute_shared_nof_implementors() {

  // We requery this property, since it is a very old ciObject.

  GUARDED_VM_ENTRY(

    instanceKlass* ik = get_instanceKlass();

    _nof_implementors = ik->nof_implementors();

    return _nof_implementors;

  )

}

// ------------------------------------------------------------------

// ciInstanceKlass::loader

oop ciInstanceKlass::loader() {

  ASSERT_IN_VM;

  return JNIHandles::resolve(_loader);

}

// ------------------------------------------------------------------

// ciInstanceKlass::loader_handle

jobject ciInstanceKlass::loader_handle() {

  return _loader;

}

// ------------------------------------------------------------------

// ciInstanceKlass::protection_domain

oop ciInstanceKlass::protection_domain() {

  ASSERT_IN_VM;

  return JNIHandles::resolve(_protection_domain);

}

// ------------------------------------------------------------------

// ciInstanceKlass::protection_domain_handle

jobject ciInstanceKlass::protection_domain_handle() {

  return _protection_domain;

}

// ------------------------------------------------------------------

// ciInstanceKlass::field_cache

//

// Get the field cache associated with this klass.

ciConstantPoolCache* ciInstanceKlass::field_cache() {

  if (is_shared()) {

    return NULL;

  }

  if (_field_cache == NULL) {

    assert(!is_java_lang_Object(), "Object has no fields");

    Arena* arena = CURRENT_ENV->arena();

    _field_cache = new (arena) ciConstantPoolCache(arena, 5);

  }

  return _field_cache;

}

// ------------------------------------------------------------------

// ciInstanceKlass::get_canonical_holder

//

ciInstanceKlass* ciInstanceKlass::get_canonical_holder(int offset) {

  #ifdef ASSERT

  if (!(offset >= 0 && offset < layout_helper())) {

    tty->print("*** get_canonical_holder(%d) on ", offset);

    this->print();

    tty->print_cr(" ***");

  };

  assert(offset >= 0 && offset < layout_helper(), "offset must be tame");

  #endif

  if (offset < (instanceOopDesc::header_size() * wordSize)) {

    // All header offsets belong properly to java/lang/Object.

    return CURRENT_ENV->Object_klass();

  }

  ciInstanceKlass* self = this;

  for (;;) {

    assert(self->is_loaded(), "must be loaded to have size");

    ciInstanceKlass* super = self->super();

    if (super == NULL || !super->contains_field_offset(offset)) {

      return self;

    } else {

      self = super;  // return super->get_canonical_holder(offset)

    }

  }

}

// ------------------------------------------------------------------

// ciInstanceKlass::is_java_lang_Object

//

// Is this klass java.lang.Object?

bool ciInstanceKlass::is_java_lang_Object() {

  return equals(CURRENT_ENV->Object_klass());

}

// ------------------------------------------------------------------

// ciInstanceKlass::uses_default_loader

bool ciInstanceKlass::uses_default_loader() {

  VM_ENTRY_MARK;

  return loader() == NULL;

}

// ------------------------------------------------------------------

// ciInstanceKlass::print_impl

//

// Implementation of the print method.

void ciInstanceKlass::print_impl(outputStream* st) {

  ciKlass::print_impl(st);

  GUARDED_VM_ENTRY(st->print(" loader=0x%x", (address)loader());)

  if (is_loaded()) {

    st->print(" loaded=true initialized=%s finalized=%s subklass=%s size=%d flags=",

              bool_to_str(is_initialized()),

              bool_to_str(has_finalizer()),

              bool_to_str(has_subklass()),

              layout_helper());

    _flags.print_klass_flags();

    if (_super) {

      st->print(" super=");

      _super->print_name();

    }

    if (_java_mirror) {

      st->print(" mirror=PRESENT");

    }

  } else {

    st->print(" loaded=false");

  }

}

// ------------------------------------------------------------------

// ciInstanceKlass::super

//

// Get the superklass of this klass.

ciInstanceKlass* ciInstanceKlass::super() {

  assert(is_loaded(), "must be loaded");

  if (_super == NULL && !is_java_lang_Object()) {

    GUARDED_VM_ENTRY(

      klassOop super_klass = get_instanceKlass()->super();

      _super = CURRENT_ENV->get_object(super_klass)->as_instance_klass();

    )

  }

  return _super;

}

// ------------------------------------------------------------------

// ciInstanceKlass::java_mirror

//

// Get the instance of java.lang.Class corresponding to this klass.

ciInstance* ciInstanceKlass::java_mirror() {

  assert(is_loaded(), "must be loaded");

  if (_java_mirror == NULL) {

    _java_mirror = ciKlass::java_mirror();

  }

  return _java_mirror;

}

// ------------------------------------------------------------------

// ciInstanceKlass::unique_concrete_subklass

ciInstanceKlass* ciInstanceKlass::unique_concrete_subklass() {

  if (!is_loaded())     return NULL; // No change if class is not loaded

  if (!is_abstract())   return NULL; // Only applies to abstract classes.

  if (!has_subklass())  return NULL; // Must have at least one subklass.

  VM_ENTRY_MARK;

  instanceKlass* ik = get_instanceKlass();

  Klass* up = ik->up_cast_abstract();

  assert(up->oop_is_instance(), "must be instanceKlass");

  if (ik == up) {

    return NULL;

  }

  return CURRENT_THREAD_ENV->get_object(up->as_klassOop())->as_instance_klass();

}

// ------------------------------------------------------------------

// ciInstanceKlass::has_finalizable_subclass

bool ciInstanceKlass::has_finalizable_subclass() {

  if (!is_loaded())     return true;

  VM_ENTRY_MARK;

  return Dependencies::find_finalizable_subclass(get_instanceKlass()) != NULL;

}

// ------------------------------------------------------------------

// ciInstanceKlass::get_field_by_offset

ciField* ciInstanceKlass::get_field_by_offset(int field_offset, bool is_static) {

  if (!is_static) {

    for (int i = 0, len = nof_nonstatic_fields(); i < len; i++) {

      ciField* field = _nonstatic_fields->at(i);

      int  field_off = field->offset_in_bytes();

      if (field_off == field_offset)

        return field;

      if (field_off > field_offset)

        break;

      // could do binary search or check bins, but probably not worth it

    }

    return NULL;

  }

  VM_ENTRY_MARK;

  instanceKlass* k = get_instanceKlass();

  fieldDescriptor fd;

  if (!k->find_field_from_offset(field_offset, is_static, &fd)) {

    return NULL;

  }

  ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);

  return field;

}

static int sort_field_by_offset(ciField** a, ciField** b) {

  return (*a)->offset_in_bytes() - (*b)->offset_in_bytes();

  // (no worries about 32-bit overflow...)

}

// ------------------------------------------------------------------

// ciInstanceKlass::compute_nonstatic_fields

int ciInstanceKlass::compute_nonstatic_fields() {

  assert(is_loaded(), "must be loaded");

  if (_nonstatic_fields != NULL)

    return _nonstatic_fields->length();

  // Size in bytes of my fields, including inherited fields.

  // About equal to size_helper() - sizeof(oopDesc).

  int fsize = nonstatic_field_size() * wordSize;

  if (fsize == 0) {     // easy shortcut

    Arena* arena = CURRENT_ENV->arena();

    _nonstatic_fields = new (arena) GrowableArray<ciField*>(arena, 0, 0, NULL);

    return 0;

  }

  assert(!is_java_lang_Object(), "bootstrap OK");

  ciInstanceKlass* super = this->super();

  int      super_fsize = 0;

  int      super_flen  = 0;

  GrowableArray<ciField*>* super_fields = NULL;

  if (super != NULL) {

    super_fsize  = super->nonstatic_field_size() * wordSize;

    super_flen   = super->nof_nonstatic_fields();

    super_fields = super->_nonstatic_fields;

    assert(super_flen == 0 || super_fields != NULL, "first get nof_fields");

  }

  // See if I am no larger than my super; if so, I can use his fields.

  if (fsize == super_fsize) {

    _nonstatic_fields = super_fields;

    return super_fields->length();

  }

  GrowableArray<ciField*>* fields = NULL;

  GUARDED_VM_ENTRY({

      fields = compute_nonstatic_fields_impl(super_fields);

    });

  if (fields == NULL) {

    // This can happen if this class (java.lang.Class) has invisible fields.

    _nonstatic_fields = super_fields;

    return super_fields->length();

  }

  int flen = fields->length();

  // Now sort them by offset, ascending.

  // (In principle, they could mix with superclass fields.)

  fields->sort(sort_field_by_offset);

#ifdef ASSERT

  int last_offset = sizeof(oopDesc);

  for (int i = 0; i < fields->length(); i++) {

    ciField* field = fields->at(i);

    int offset = field->offset_in_bytes();

    int size   = (field->_type == NULL) ? oopSize : field->size_in_bytes();

    assert(last_offset <= offset, "no field overlap");

    if (last_offset > (int)sizeof(oopDesc))

      assert((offset - last_offset) < BytesPerLong, "no big holes");

    // Note:  Two consecutive T_BYTE fields will be separated by wordSize-1

    // padding bytes if one of them is declared by a superclass.

    // This is a minor inefficiency classFileParser.cpp.

    last_offset = offset + size;

  }

  assert(last_offset <= (int)sizeof(oopDesc) + fsize, "no overflow");

#endif

  _nonstatic_fields = fields;

  return flen;

}

GrowableArray<ciField*>*

ciInstanceKlass::compute_nonstatic_fields_impl(GrowableArray<ciField*>*

                                               super_fields) {

  ASSERT_IN_VM;

  Arena* arena = CURRENT_ENV->arena();

  int flen = 0;

  GrowableArray<ciField*>* fields = NULL;

  instanceKlass* k = get_instanceKlass();

  typeArrayOop fields_array = k->fields();

  for (int pass = 0; pass <= 1; pass++) {

    for (int i = 0, alen = fields_array->length(); i < alen; i += instanceKlass::next_offset) {

      fieldDescriptor fd;

      fd.initialize(k->as_klassOop(), i);

      if (fd.is_static())  continue;

      if (pass == 0) {

        flen += 1;

      } else {

        ciField* field = new (arena) ciField(&fd);

        fields->append(field);

      }

    }

    // Between passes, allocate the array:

    if (pass == 0) {

      if (flen == 0) {

        return NULL;  // return nothing if none are locally declared

      }

      if (super_fields != NULL) {

        flen += super_fields->length();

      }

      fields = new (arena) GrowableArray<ciField*>(arena, flen, 0, NULL);

      if (super_fields != NULL) {

        fields->appendAll(super_fields);

      }

    }

  }

  assert(fields->length() == flen, "sanity");

  return fields;

}

// ------------------------------------------------------------------

// ciInstanceKlass::find_method

//

// Find a method in this klass.

ciMethod* ciInstanceKlass::find_method(ciSymbol* name, ciSymbol* signature) {

  VM_ENTRY_MARK;

  instanceKlass* k = get_instanceKlass();

  symbolOop name_sym = name->get_symbolOop();

  symbolOop sig_sym= signature->get_symbolOop();

  methodOop m = k->find_method(name_sym, sig_sym);

  if (m == NULL)  return NULL;

  return CURRENT_THREAD_ENV->get_object(m)->as_method();

}

// ------------------------------------------------------------------

// ciInstanceKlass::is_leaf_type

bool ciInstanceKlass::is_leaf_type() {

  assert(is_loaded(), "must be loaded");

  if (is_shared()) {

    return is_final();  // approximately correct

  } else {

    return !_has_subklass && (_nof_implementors == 0);

  }

}

// ------------------------------------------------------------------

// ciInstanceKlass::implementor

//

// Report an implementor of this interface.

// Returns NULL if exact information is not available.

// Note that there are various races here, since my copy

// of _nof_implementors might be out of date with respect

// to results returned by instanceKlass::implementor.

// This is OK, since any dependencies we decide to assert

// will be checked later under the Compile_lock.

ciInstanceKlass* ciInstanceKlass::implementor(int n) {

  if (n > implementors_limit) {

    return NULL;

  }

  ciInstanceKlass* impl = _implementors[n];

  if (impl == NULL) {

    if (_nof_implementors > implementors_limit) {

      return NULL;

    }

    // Go into the VM to fetch the implementor.

    {

      VM_ENTRY_MARK;

      klassOop k = get_instanceKlass()->implementor(n);

      if (k != NULL) {

        impl = CURRENT_THREAD_ENV->get_object(k)->as_instance_klass();

      }

    }

    // Memoize this result.

    if (!is_shared()) {

      _implementors[n] = (impl == NULL)? this: impl;

    }

  } else if (impl == this) {

    impl = NULL;  // memoized null result from a VM query

  }

  return impl;

}