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src/hotspot/share/ci/ciField.cpp

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 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #include "ci/ciField.hpp"
 26 #include "ci/ciInstanceKlass.hpp"
 27 #include "ci/ciSymbols.hpp"
 28 #include "ci/ciUtilities.inline.hpp"
 29 #include "classfile/javaClasses.hpp"
 30 #include "classfile/vmClasses.hpp"

 31 #include "gc/shared/collectedHeap.inline.hpp"
 32 #include "interpreter/linkResolver.hpp"
 33 #include "oops/klass.inline.hpp"
 34 #include "oops/oop.inline.hpp"
 35 #include "runtime/fieldDescriptor.inline.hpp"
 36 #include "runtime/handles.inline.hpp"
 37 #include "runtime/reflection.hpp"
 38 
 39 // ciField
 40 //
 41 // This class represents the result of a field lookup in the VM.
 42 // The lookup may not succeed, in which case the information in
 43 // the ciField will be incomplete.
 44 
 45 // The ciObjectFactory cannot create circular data structures in one query.
 46 // To avoid vicious circularities, we initialize ciField::_type to null
 47 // for reference types and derive it lazily from the ciField::_signature.
 48 // Primitive types are eagerly initialized, and basic layout queries
 49 // can succeed without initialization, using only the BasicType of the field.
 50 

274     }
275   }
276 }
277 
278 // ------------------------------------------------------------------
279 // ciField::constant_value
280 // Get the constant value of a this static field.
281 ciConstant ciField::constant_value() {
282   assert(is_static() && is_constant(), "illegal call to constant_value()");
283   if (!_holder->is_initialized()) {
284     return ciConstant(); // Not initialized yet
285   }
286   if (_constant_value.basic_type() == T_ILLEGAL) {
287     // Static fields are placed in mirror objects.
288     ciInstance* mirror = _holder->java_mirror();
289     _constant_value = mirror->field_value_impl(type()->basic_type(), offset_in_bytes());
290   }
291   if (FoldStableValues && is_stable() && _constant_value.is_null_or_zero()) {
292     return ciConstant();
293   }



294   return _constant_value;
295 }
296 
297 // ------------------------------------------------------------------
298 // ciField::constant_value_of
299 // Get the constant value of non-static final field in the given object.
300 ciConstant ciField::constant_value_of(ciObject* object) {
301   assert(!is_static() && is_constant(), "only if field is non-static constant");
302   assert(object->is_instance(), "must be instance");
303   ciConstant field_value = object->as_instance()->field_value(this);
304   if (FoldStableValues && is_stable() && field_value.is_null_or_zero()) {
305     return ciConstant();
306   }



307   return field_value;
308 }
309 
310 // ------------------------------------------------------------------
311 // ciField::compute_type
312 //
313 // Lazily compute the type, if it is an instance klass.
314 ciType* ciField::compute_type() {
315   GUARDED_VM_ENTRY(return compute_type_impl();)
316 }
317 
318 ciType* ciField::compute_type_impl() {
319   ciKlass* type = CURRENT_ENV->get_klass_by_name_impl(_holder, constantPoolHandle(), _signature, false);
320   if (!type->is_primitive_type() && is_shared()) {
321     // We must not cache a pointer to an unshared type, in a shared field.
322     bool type_is_also_shared = false;
323     if (type->is_type_array_klass()) {
324       type_is_also_shared = true;  // int[] etc. are explicitly bootstrapped
325     } else if (type->is_instance_klass()) {
326       type_is_also_shared = type->as_instance_klass()->is_shared();

 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #include "ci/ciField.hpp"
 26 #include "ci/ciInstanceKlass.hpp"
 27 #include "ci/ciSymbols.hpp"
 28 #include "ci/ciUtilities.inline.hpp"
 29 #include "classfile/javaClasses.hpp"
 30 #include "classfile/vmClasses.hpp"
 31 #include "code/aotCodeCache.hpp"
 32 #include "gc/shared/collectedHeap.inline.hpp"
 33 #include "interpreter/linkResolver.hpp"
 34 #include "oops/klass.inline.hpp"
 35 #include "oops/oop.inline.hpp"
 36 #include "runtime/fieldDescriptor.inline.hpp"
 37 #include "runtime/handles.inline.hpp"
 38 #include "runtime/reflection.hpp"
 39 
 40 // ciField
 41 //
 42 // This class represents the result of a field lookup in the VM.
 43 // The lookup may not succeed, in which case the information in
 44 // the ciField will be incomplete.
 45 
 46 // The ciObjectFactory cannot create circular data structures in one query.
 47 // To avoid vicious circularities, we initialize ciField::_type to null
 48 // for reference types and derive it lazily from the ciField::_signature.
 49 // Primitive types are eagerly initialized, and basic layout queries
 50 // can succeed without initialization, using only the BasicType of the field.
 51 

275     }
276   }
277 }
278 
279 // ------------------------------------------------------------------
280 // ciField::constant_value
281 // Get the constant value of a this static field.
282 ciConstant ciField::constant_value() {
283   assert(is_static() && is_constant(), "illegal call to constant_value()");
284   if (!_holder->is_initialized()) {
285     return ciConstant(); // Not initialized yet
286   }
287   if (_constant_value.basic_type() == T_ILLEGAL) {
288     // Static fields are placed in mirror objects.
289     ciInstance* mirror = _holder->java_mirror();
290     _constant_value = mirror->field_value_impl(type()->basic_type(), offset_in_bytes());
291   }
292   if (FoldStableValues && is_stable() && _constant_value.is_null_or_zero()) {
293     return ciConstant();
294   }
295   if (!AOTCodeCache::allow_const_field(_constant_value)) {
296     return ciConstant();
297   }
298   return _constant_value;
299 }
300 
301 // ------------------------------------------------------------------
302 // ciField::constant_value_of
303 // Get the constant value of non-static final field in the given object.
304 ciConstant ciField::constant_value_of(ciObject* object) {
305   assert(!is_static() && is_constant(), "only if field is non-static constant");
306   assert(object->is_instance(), "must be instance");
307   ciConstant field_value = object->as_instance()->field_value(this);
308   if (FoldStableValues && is_stable() && field_value.is_null_or_zero()) {
309     return ciConstant();
310   }
311   if (!AOTCodeCache::allow_const_field(field_value)) {
312     return ciConstant();
313   }
314   return field_value;
315 }
316 
317 // ------------------------------------------------------------------
318 // ciField::compute_type
319 //
320 // Lazily compute the type, if it is an instance klass.
321 ciType* ciField::compute_type() {
322   GUARDED_VM_ENTRY(return compute_type_impl();)
323 }
324 
325 ciType* ciField::compute_type_impl() {
326   ciKlass* type = CURRENT_ENV->get_klass_by_name_impl(_holder, constantPoolHandle(), _signature, false);
327   if (!type->is_primitive_type() && is_shared()) {
328     // We must not cache a pointer to an unshared type, in a shared field.
329     bool type_is_also_shared = false;
330     if (type->is_type_array_klass()) {
331       type_is_also_shared = true;  // int[] etc. are explicitly bootstrapped
332     } else if (type->is_instance_klass()) {
333       type_is_also_shared = type->as_instance_klass()->is_shared();
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