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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 

297     }
298   }
299 }
300 
301 // ------------------------------------------------------------------
302 // ciField::constant_value
303 // Get the constant value of a this static field.
304 ciConstant ciField::constant_value() {
305   assert(is_static() && is_constant(), "illegal call to constant_value()");
306   if (!_holder->is_initialized()) {
307     return ciConstant(); // Not initialized yet
308   }
309   if (_constant_value.basic_type() == T_ILLEGAL) {
310     // Static fields are placed in mirror objects.
311     ciInstance* mirror = _holder->java_mirror();
312     _constant_value = mirror->field_value_impl(type()->basic_type(), offset_in_bytes());
313   }
314   if (FoldStableValues && is_stable() && _constant_value.is_null_or_zero()) {
315     return ciConstant();
316   }



317   return _constant_value;
318 }
319 
320 // ------------------------------------------------------------------
321 // ciField::constant_value_of
322 // Get the constant value of non-static final field in the given object.
323 ciConstant ciField::constant_value_of(ciObject* object) {
324   assert(!is_static() && is_constant(), "only if field is non-static constant");
325   assert(object->is_instance(), "must be instance");
326   ciConstant field_value = object->as_instance()->field_value(this);
327   if (FoldStableValues && is_stable() && field_value.is_null_or_zero()) {
328     return ciConstant();
329   }



330   return field_value;
331 }
332 
333 // ------------------------------------------------------------------
334 // ciField::compute_type
335 //
336 // Lazily compute the type, if it is an instance klass.
337 ciType* ciField::compute_type() {
338   GUARDED_VM_ENTRY(return compute_type_impl();)
339 }
340 
341 ciType* ciField::compute_type_impl() {
342   ciKlass* type = CURRENT_ENV->get_klass_by_name_impl(_holder, constantPoolHandle(), _signature, false);
343   if (!type->is_primitive_type() && is_shared()) {
344     // We must not cache a pointer to an unshared type, in a shared field.
345     bool type_is_also_shared = false;
346     if (type->is_type_array_klass()) {
347       type_is_also_shared = true;  // int[] etc. are explicitly bootstrapped
348     } else if (type->is_instance_klass()) {
349       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/SCCache.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 

298     }
299   }
300 }
301 
302 // ------------------------------------------------------------------
303 // ciField::constant_value
304 // Get the constant value of a this static field.
305 ciConstant ciField::constant_value() {
306   assert(is_static() && is_constant(), "illegal call to constant_value()");
307   if (!_holder->is_initialized()) {
308     return ciConstant(); // Not initialized yet
309   }
310   if (_constant_value.basic_type() == T_ILLEGAL) {
311     // Static fields are placed in mirror objects.
312     ciInstance* mirror = _holder->java_mirror();
313     _constant_value = mirror->field_value_impl(type()->basic_type(), offset_in_bytes());
314   }
315   if (FoldStableValues && is_stable() && _constant_value.is_null_or_zero()) {
316     return ciConstant();
317   }
318   if (!SCCache::allow_const_field(_constant_value)) {
319     return ciConstant();
320   }
321   return _constant_value;
322 }
323 
324 // ------------------------------------------------------------------
325 // ciField::constant_value_of
326 // Get the constant value of non-static final field in the given object.
327 ciConstant ciField::constant_value_of(ciObject* object) {
328   assert(!is_static() && is_constant(), "only if field is non-static constant");
329   assert(object->is_instance(), "must be instance");
330   ciConstant field_value = object->as_instance()->field_value(this);
331   if (FoldStableValues && is_stable() && field_value.is_null_or_zero()) {
332     return ciConstant();
333   }
334   if (!SCCache::allow_const_field(field_value)) {
335     return ciConstant();
336   }
337   return field_value;
338 }
339 
340 // ------------------------------------------------------------------
341 // ciField::compute_type
342 //
343 // Lazily compute the type, if it is an instance klass.
344 ciType* ciField::compute_type() {
345   GUARDED_VM_ENTRY(return compute_type_impl();)
346 }
347 
348 ciType* ciField::compute_type_impl() {
349   ciKlass* type = CURRENT_ENV->get_klass_by_name_impl(_holder, constantPoolHandle(), _signature, false);
350   if (!type->is_primitive_type() && is_shared()) {
351     // We must not cache a pointer to an unshared type, in a shared field.
352     bool type_is_also_shared = false;
353     if (type->is_type_array_klass()) {
354       type_is_also_shared = true;  // int[] etc. are explicitly bootstrapped
355     } else if (type->is_instance_klass()) {
356       type_is_also_shared = type->as_instance_klass()->is_shared();
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