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 /*

  * Copyright (c) 1999, 2010, 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

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  */

 #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), _non_static_fields(NULL)

 {

   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;

   _init_state = (instanceKlass::ClassState)ik->get_init_state();

   _nonstatic_field_size = ik->nonstatic_field_size();

   _has_nonstatic_fields = ik->has_nonstatic_fields();

   _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");

   _init_state = (instanceKlass::ClassState)0;

   _nonstatic_field_size = -1;

   _has_nonstatic_fields = false;

   _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

 void ciInstanceKlass::compute_shared_init_state() {

   GUARDED_VM_ENTRY(

     instanceKlass* ik = get_instanceKlass();

     _init_state = (instanceKlass::ClassState)ik->get_init_state();

   )

 }

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

 // 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::base_offset_in_bytes()) {

     // 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->nof_nonstatic_fields() == 0 ||

         !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() {

   // Note:  We do not need to resolve the handle or enter the VM

   // in order to test null-ness.

   return _loader == NULL;

 }

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

 // ciInstanceKlass::is_in_package

 //

 // Is this klass in the given package?

 bool ciInstanceKlass::is_in_package(const char* packagename, int len) {

   // To avoid class loader mischief, this test always rejects application classes.

   if (!uses_default_loader())

     return false;

   GUARDED_VM_ENTRY(

     return is_in_package_impl(packagename, len);

   )

 }

 bool ciInstanceKlass::is_in_package_impl(const char* packagename, int len) {

   ASSERT_IN_VM;

   // If packagename contains trailing '/' exclude it from the

   // prefix-test since we test for it explicitly.

   if (packagename[len - 1] == '/')

     len--;

   if (!name()->starts_with(packagename, len))

     return false;

   // Test if the class name is something like "java/lang".

   if ((len + 1) > name()->utf8_length())

     return false;

   // Test for trailing '/'

   if ((char) name()->byte_at(len) != '/')

     return false;

   // Make sure it's not actually in a subpackage:

   if (name()->index_of_at(len+1, "/", 1) >= 0)

     return false;

   return true;

 }

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

 // 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.

 // Cache it on this->_java_mirror.

 ciInstance* ciInstanceKlass::java_mirror() {

   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;

 }

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

 // ciInstanceKlass::get_field_by_name

 ciField* ciInstanceKlass::get_field_by_name(ciSymbol* name, ciSymbol* signature, bool is_static) {

   VM_ENTRY_MARK;

   instanceKlass* k = get_instanceKlass();

   fieldDescriptor fd;

   klassOop def = k->find_field(name->get_symbolOop(), signature->get_symbolOop(), is_static, &fd);

   if (def == NULL) {

     return NULL;

   }

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

   return field;

 }

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

 // ciInstanceKlass::non_static_fields.

 class NonStaticFieldFiller: public FieldClosure {

   GrowableArray<ciField*>* _arr;

   ciEnv* _curEnv;

 public:

   NonStaticFieldFiller(ciEnv* curEnv, GrowableArray<ciField*>* arr) :

     _curEnv(curEnv), _arr(arr)

   {}

   void do_field(fieldDescriptor* fd) {

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

     _arr->append(field);

   }

 };

 GrowableArray<ciField*>* ciInstanceKlass::non_static_fields() {

   if (_non_static_fields == NULL) {

     VM_ENTRY_MARK;

     ciEnv* curEnv = ciEnv::current();

     instanceKlass* ik = get_instanceKlass();

     int max_n_fields = ik->fields()->length()/instanceKlass::next_offset;

     Arena* arena = curEnv->arena();

     _non_static_fields =

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

     NonStaticFieldFiller filler(curEnv, _non_static_fields);

     ik->do_nonstatic_fields(&filler);

   }

   return _non_static_fields;

 }

 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();

   if (!has_nonstatic_fields()) {

     Arena* arena = CURRENT_ENV->arena();

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

     return 0;

   }

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

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

   int fsize = nonstatic_field_size() * heapOopSize;

   ciInstanceKlass* super = this->super();

   GrowableArray<ciField*>* super_fields = NULL;

   if (super != NULL && super->has_nonstatic_fields()) {

     int super_fsize  = super->nonstatic_field_size() * heapOopSize;

     int 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 = instanceOopDesc::base_offset_in_bytes();

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

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

     int offset = field->offset_in_bytes();

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

     assert(last_offset <= offset, err_msg("no field overlap: %d <= %d", last_offset, offset));

     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)instanceOopDesc::base_offset_in_bytes() + 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;

 }