1 /*
  2  * Copyright (c) 1997, 2021, 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 "precompiled.hpp"
 26 #include "classfile/vmSymbols.hpp"
 27 #include "memory/resourceArea.hpp"
 28 #include "oops/annotations.hpp"
 29 #include "oops/constantPool.hpp"
 30 #include "oops/instanceKlass.hpp"
 31 #include "oops/klass.inline.hpp"
 32 #include "oops/oop.inline.hpp"
 33 #include "oops/fieldStreams.inline.hpp"
 34 #include "oops/inlineKlass.inline.hpp"
 35 #include "runtime/fieldDescriptor.inline.hpp"
 36 #include "runtime/handles.inline.hpp"
 37 #include "runtime/signature.hpp"
 38 
 39 Symbol* fieldDescriptor::generic_signature() const {
 40   if (!has_generic_signature()) {
 41     return NULL;
 42   }
 43 
 44   int idx = 0;
 45   InstanceKlass* ik = field_holder();
 46   for (AllFieldStream fs(ik); !fs.done(); fs.next()) {
 47     if (idx == _index) {
 48       return fs.generic_signature();
 49     } else {
 50       idx ++;
 51     }
 52   }
 53   assert(false, "should never happen");
 54   return vmSymbols::void_signature(); // return a default value (for code analyzers)
 55 }
 56 
 57 bool fieldDescriptor::is_trusted_final() const {
 58   InstanceKlass* ik = field_holder();
 59   return is_final() && (is_static() || ik->is_hidden() || ik->is_record() || ik->is_inline_klass());
 60 }
 61 
 62 AnnotationArray* fieldDescriptor::annotations() const {
 63   InstanceKlass* ik = field_holder();
 64   Array<AnnotationArray*>* md = ik->fields_annotations();
 65   if (md == NULL)
 66     return NULL;
 67   return md->at(index());
 68 }
 69 
 70 AnnotationArray* fieldDescriptor::type_annotations() const {
 71   InstanceKlass* ik = field_holder();
 72   Array<AnnotationArray*>* type_annos = ik->fields_type_annotations();
 73   if (type_annos == NULL)
 74     return NULL;
 75   return type_annos->at(index());
 76 }
 77 
 78 constantTag fieldDescriptor::initial_value_tag() const {
 79   return constants()->tag_at(initial_value_index());
 80 }
 81 
 82 jint fieldDescriptor::int_initial_value() const {
 83   return constants()->int_at(initial_value_index());
 84 }
 85 
 86 jlong fieldDescriptor::long_initial_value() const {
 87   return constants()->long_at(initial_value_index());
 88 }
 89 
 90 jfloat fieldDescriptor::float_initial_value() const {
 91   return constants()->float_at(initial_value_index());
 92 }
 93 
 94 jdouble fieldDescriptor::double_initial_value() const {
 95   return constants()->double_at(initial_value_index());
 96 }
 97 
 98 oop fieldDescriptor::string_initial_value(TRAPS) const {
 99   return constants()->uncached_string_at(initial_value_index(), THREAD);
100 }
101 
102 void fieldDescriptor::reinitialize(InstanceKlass* ik, int index) {
103   if (_cp.is_null() || field_holder() != ik) {
104     _cp = constantPoolHandle(Thread::current(), ik->constants());
105     // _cp should now reference ik's constant pool; i.e., ik is now field_holder.
106     assert(field_holder() == ik, "must be already initialized to this class");
107   }
108   FieldInfo* f = ik->field(index);
109   _access_flags = accessFlags_from(f->access_flags());
110   guarantee(f->name_index() != 0 && f->signature_index() != 0, "bad constant pool index for fieldDescriptor");
111   _index = index;
112   verify();
113 }
114 
115 #ifndef PRODUCT
116 
117 void fieldDescriptor::verify() const {
118   if (_cp.is_null()) {
119     assert(_index == badInt, "constructor must be called");  // see constructor
120   } else {
121     assert(_index >= 0, "good index");
122     assert(access_flags().is_internal() ||
123            _index < field_holder()->java_fields_count(), "oob");
124   }
125 }
126 
127 #endif /* PRODUCT */
128 
129 void fieldDescriptor::print_on(outputStream* st) const {
130   access_flags().print_on(st);
131   if (access_flags().is_internal()) st->print("internal ");
132   name()->print_value_on(st);
133   st->print(" ");
134   signature()->print_value_on(st);
135   st->print(" @%d ", offset());
136   if (WizardMode && has_initial_value()) {
137     st->print("(initval ");
138     constantTag t = initial_value_tag();
139     if (t.is_int()) {
140       st->print("int %d)", int_initial_value());
141     } else if (t.is_long()){
142       st->print_jlong(long_initial_value());
143     } else if (t.is_float()){
144       st->print("float %f)", float_initial_value());
145     } else if (t.is_double()){
146       st->print("double %lf)", double_initial_value());
147     }
148   }
149 }
150 
151 void fieldDescriptor::print() const { print_on(tty); }
152 
153 void fieldDescriptor::print_on_for(outputStream* st, oop obj) {
154   BasicType ft = field_type();
155   if (ft != T_PRIMITIVE_OBJECT) {
156     print_on(st);
157     st->print(" ");
158   }
159   jint as_int = 0;
160   switch (ft) {
161     case T_BYTE:
162       st->print("%d", obj->byte_field(offset()));
163       break;
164     case T_CHAR:
165       {
166         jchar c = obj->char_field(offset());
167         st->print("%c %d", isprint(c) ? c : ' ', c);
168       }
169       break;
170     case T_DOUBLE:
171       st->print("%lf", obj->double_field(offset()));
172       break;
173     case T_FLOAT:
174       st->print("%f", obj->float_field(offset()));
175       break;
176     case T_INT:
177       st->print("%d", obj->int_field(offset()));
178       break;
179     case T_LONG:
180       st->print_jlong(obj->long_field(offset()));
181       break;
182     case T_SHORT:
183       st->print("%d", obj->short_field(offset()));
184       break;
185     case T_BOOLEAN:
186       st->print("%s", obj->bool_field(offset()) ? "true" : "false");
187       break;
188     case T_PRIMITIVE_OBJECT:
189       if (is_inlined()) {
190         // Print fields of inlined fields (recursively)
191         InlineKlass* vk = InlineKlass::cast(field_holder()->get_inline_type_field_klass(index()));
192         int field_offset = offset() - vk->first_field_offset();
193         obj = cast_to_oop(cast_from_oop<address>(obj) + field_offset);
194         st->print_cr("Inline type field inlined '%s':", vk->name()->as_C_string());
195         FieldPrinter print_field(st, obj);
196         vk->do_nonstatic_fields(&print_field);
197         return; // Do not print underlying representation
198       }
199       // inline type field not inlined, fall through
200     case T_ARRAY:
201     case T_OBJECT:
202       if (obj->obj_field(offset()) != NULL) {
203         obj->obj_field(offset())->print_value_on(st);
204       } else {
205         st->print("NULL");
206       }
207       break;
208     default:
209       ShouldNotReachHere();
210       break;
211   }
212 
213   // Print a hint as to the underlying integer representation.
214   if (is_reference_type(ft)) {
215 #ifdef _LP64
216     if (UseCompressedOops) {
217       st->print(" (" INT32_FORMAT_X_0 ")", obj->int_field(offset()));
218     } else {
219       st->print(" (" INT64_FORMAT_X_0 ")", (int64_t)obj->long_field(offset()));
220     }
221 #else
222     st->print(" (" INT32_FORMAT_X_0 ")", obj->int_field(offset()));
223 #endif
224   } else { // Primitives
225     switch (ft) {
226       case T_LONG:    st->print(" (" INT64_FORMAT_X_0 ")", (int64_t)obj->long_field(offset())); break;
227       case T_DOUBLE:  st->print(" (" INT64_FORMAT_X_0 ")", (int64_t)obj->long_field(offset())); break;
228       case T_BYTE:    st->print(" (" INT8_FORMAT_X_0  ")", obj->byte_field(offset()));          break;
229       case T_CHAR:    st->print(" (" INT16_FORMAT_X_0 ")", obj->char_field(offset()));          break;
230       case T_FLOAT:   st->print(" (" INT32_FORMAT_X_0 ")", obj->int_field(offset()));           break;
231       case T_INT:     st->print(" (" INT32_FORMAT_X_0 ")", obj->int_field(offset()));           break;
232       case T_SHORT:   st->print(" (" INT16_FORMAT_X_0 ")", obj->short_field(offset()));         break;
233       case T_BOOLEAN: st->print(" (" INT8_FORMAT_X_0  ")", obj->bool_field(offset()));          break;
234     default:
235       ShouldNotReachHere();
236       break;
237     }
238   }
239   st->cr();
240 }