1 /*
  2  * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 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 "classfile/vmSymbols.hpp"
 26 #include "memory/resourceArea.hpp"
 27 #include "oops/annotations.hpp"
 28 #include "oops/constantPool.hpp"
 29 #include "oops/instanceKlass.hpp"
 30 #include "oops/klass.inline.hpp"
 31 #include "oops/oop.inline.hpp"
 32 #include "oops/fieldStreams.inline.hpp"
 33 #include "oops/inlineKlass.inline.hpp"
 34 #include "runtime/fieldDescriptor.inline.hpp"
 35 #include "runtime/handles.inline.hpp"
 36 #include "runtime/signature.hpp"
 37 
 38 Symbol* fieldDescriptor::generic_signature() const {
 39   if (!has_generic_signature()) {
 40     return nullptr;
 41   }
 42   return _cp->symbol_at(_fieldinfo.generic_signature_index());
 43 }
 44 
 45 bool fieldDescriptor::is_trusted_final() const {
 46   InstanceKlass* ik = field_holder();
 47   return is_final() && (is_static() || ik->is_hidden() || ik->is_record() || ik->is_inline_klass()
 48                         || (ik->is_abstract() && !ik->is_identity_class() && !ik->is_interface()));
 49 }
 50 
 51 AnnotationArray* fieldDescriptor::annotations() const {
 52   InstanceKlass* ik = field_holder();
 53   Array<AnnotationArray*>* md = ik->fields_annotations();
 54   if (md == nullptr)
 55     return nullptr;
 56   return md->at(index());
 57 }
 58 
 59 AnnotationArray* fieldDescriptor::type_annotations() const {
 60   InstanceKlass* ik = field_holder();
 61   Array<AnnotationArray*>* type_annos = ik->fields_type_annotations();
 62   if (type_annos == nullptr)
 63     return nullptr;
 64   return type_annos->at(index());
 65 }
 66 
 67 constantTag fieldDescriptor::initial_value_tag() const {
 68   return constants()->tag_at(initial_value_index());
 69 }
 70 
 71 jint fieldDescriptor::int_initial_value() const {
 72   return constants()->int_at(initial_value_index());
 73 }
 74 
 75 jlong fieldDescriptor::long_initial_value() const {
 76   return constants()->long_at(initial_value_index());
 77 }
 78 
 79 jfloat fieldDescriptor::float_initial_value() const {
 80   return constants()->float_at(initial_value_index());
 81 }
 82 
 83 jdouble fieldDescriptor::double_initial_value() const {
 84   return constants()->double_at(initial_value_index());
 85 }
 86 
 87 oop fieldDescriptor::string_initial_value(TRAPS) const {
 88   return constants()->uncached_string_at(initial_value_index(), THREAD);
 89 }
 90 
 91 void fieldDescriptor::reinitialize(InstanceKlass* ik, int index) {
 92   if (_cp.is_null() || field_holder() != ik) {
 93     _cp = constantPoolHandle(Thread::current(), ik->constants());
 94     // _cp should now reference ik's constant pool; i.e., ik is now field_holder.
 95     // If the class is a scratch class, the constant pool points to the original class,
 96     // but that's ok because of constant pool merging.
 97     assert(field_holder() == ik || ik->is_scratch_class(), "must be already initialized to this class");
 98   }
 99   _fieldinfo= ik->field(index);
100   assert((int)_fieldinfo.index() == index, "just checking");
101   guarantee(_fieldinfo.name_index() != 0 && _fieldinfo.signature_index() != 0, "bad constant pool index for fieldDescriptor");
102 }
103 
104 void fieldDescriptor::print_on(outputStream* st, int base_offset) const {
105   access_flags().print_on(st);
106   if (field_flags().is_injected()) st->print("injected ");
107   name()->print_value_on(st);
108   st->print(" ");
109   signature()->print_value_on(st);
110   st->print(" @%d ", offset() + base_offset);
111   if (WizardMode && has_initial_value()) {
112     st->print("(initval ");
113     constantTag t = initial_value_tag();
114     if (t.is_int()) {
115       st->print("int %d)", int_initial_value());
116     } else if (t.is_long()){
117       st->print_jlong(long_initial_value());
118     } else if (t.is_float()){
119       st->print("float %f)", float_initial_value());
120     } else if (t.is_double()){
121       st->print("double %lf)", double_initial_value());
122     }
123   }
124 }
125 
126 void fieldDescriptor::print() const { print_on(tty); }
127 
128 void fieldDescriptor::print_on_for(outputStream* st, oop obj, int indent, int base_offset) {
129   BasicType ft = field_type();
130   print_on(st, base_offset);
131   st->print(" ");
132   jint as_int = 0;
133   switch (ft) {
134     case T_BYTE:
135       st->print("%d", obj->byte_field(offset()));
136       break;
137     case T_CHAR:
138       {
139         jchar c = obj->char_field(offset());
140         st->print("%c %d", isprint(c) ? c : ' ', c);
141       }
142       break;
143     case T_DOUBLE:
144       st->print("%lf", obj->double_field(offset()));
145       break;
146     case T_FLOAT:
147       st->print("%f", obj->float_field(offset()));
148       break;
149     case T_INT:
150       st->print("%d", obj->int_field(offset()));
151       break;
152     case T_LONG:
153       st->print_jlong(obj->long_field(offset()));
154       break;
155     case T_SHORT:
156       st->print("%d", obj->short_field(offset()));
157       break;
158     case T_BOOLEAN:
159       st->print("%s", obj->bool_field(offset()) ? "true" : "false");
160       break;
161     case T_ARRAY:
162     case T_OBJECT:
163       if (is_flat()) { // only some inline types can be flat
164         InlineKlass* vk = InlineKlass::cast(field_holder()->get_inline_type_field_klass(index()));
165         st->print("Flat inline type field '%s':", vk->name()->as_C_string());
166         if (!is_null_free_inline_type()) {
167           assert(has_null_marker(), "should have null marker");
168           InlineLayoutInfo* li = field_holder()->inline_layout_info_adr(index());
169           int nm_offset = li->null_marker_offset();
170           if (obj->byte_field_acquire(nm_offset) == 0) {
171             st->print(" null");
172             return;
173           }
174         }
175         st->cr();
176         // Print fields of flat field (recursively)
177         int field_offset = offset() - vk->payload_offset();
178         obj = cast_to_oop(cast_from_oop<address>(obj) + field_offset);
179         FieldPrinter print_field(st, obj, indent + 1, base_offset + field_offset );
180         vk->do_nonstatic_fields(&print_field);
181         if (this->field_flags().has_null_marker()) {
182           for (int i = 0; i < indent + 1; i++) st->print("  ");
183           st->print_cr(" - [null_marker] @%d %s",
184                     vk->null_marker_offset() - base_offset + field_offset,
185                     obj->bool_field(vk->null_marker_offset()) ? "Field marked as non-null" : "Field marked as null");
186         }
187         return; // Do not print underlying representation
188       }
189       // Not flat inline type field, fall through
190       if (obj->obj_field(offset()) != nullptr) {
191         obj->obj_field(offset())->print_value_on(st);
192       } else {
193         st->print("null");
194       }
195       break;
196     default:
197       ShouldNotReachHere();
198       break;
199   }
200 
201   // Print a hint as to the underlying integer representation.
202   if (is_reference_type(ft)) {
203 #ifdef _LP64
204     if (UseCompressedOops) {
205       st->print(" (" INT32_FORMAT_X_0 ")", obj->int_field(offset()));
206     } else {
207       st->print(" (" INT64_FORMAT_X_0 ")", (int64_t)obj->long_field(offset()));
208     }
209 #else
210     st->print(" (" INT32_FORMAT_X_0 ")", obj->int_field(offset()));
211 #endif
212   } else { // Primitives
213     switch (ft) {
214       case T_LONG:    st->print(" (" INT64_FORMAT_X_0 ")", (int64_t)obj->long_field(offset())); break;
215       case T_DOUBLE:  st->print(" (" INT64_FORMAT_X_0 ")", (int64_t)obj->long_field(offset())); break;
216       case T_BYTE:    st->print(" (" INT8_FORMAT_X_0  ")", obj->byte_field(offset()));          break;
217       case T_CHAR:    st->print(" (" INT16_FORMAT_X_0 ")", obj->char_field(offset()));          break;
218       case T_FLOAT:   st->print(" (" INT32_FORMAT_X_0 ")", obj->int_field(offset()));           break;
219       case T_INT:     st->print(" (" INT32_FORMAT_X_0 ")", obj->int_field(offset()));           break;
220       case T_SHORT:   st->print(" (" INT16_FORMAT_X_0 ")", obj->short_field(offset()));         break;
221       case T_BOOLEAN: st->print(" (" INT8_FORMAT_X_0  ")", obj->bool_field(offset()));          break;
222     default:
223       ShouldNotReachHere();
224       break;
225     }
226   }
227 }