1 /*
  2  * Copyright (c) 1999, 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 "ci/ciInstanceKlass.hpp"
 27 #include "ci/ciObjArrayKlass.hpp"
 28 #include "ci/ciSymbol.hpp"
 29 #include "ci/ciUtilities.inline.hpp"
 30 #include "oops/objArrayKlass.hpp"
 31 #include "runtime/signature.hpp"
 32 
 33 // ciObjArrayKlass
 34 //
 35 // This class represents a Klass* in the HotSpot virtual machine
 36 // whose Klass part is an ObjArrayKlass.
 37 
 38 // ------------------------------------------------------------------
 39 // ciObjArrayKlass::ciObjArrayKlass
 40 //
 41 // Constructor for loaded object array klasses.
 42 ciObjArrayKlass::ciObjArrayKlass(Klass* k) : ciArrayKlass(k) {
 43   assert(get_Klass()->is_objArray_klass(), "wrong type");
 44   Klass* element_Klass = get_ObjArrayKlass()->bottom_klass();
 45   _base_element_klass = CURRENT_ENV->get_klass(element_Klass);
 46   assert(_base_element_klass->is_instance_klass() ||
 47          _base_element_klass->is_type_array_klass(), "bad base klass");
 48   if (dimension() == 1) {
 49     _element_klass = _base_element_klass;
 50   } else {
 51     _element_klass = NULL;
 52   }
 53   if (!ciObjectFactory::is_initialized()) {
 54     assert(_element_klass->is_java_lang_Object(), "only arrays of object are shared");
 55   }
 56 }
 57 
 58 // ------------------------------------------------------------------
 59 // ciObjArrayKlass::ciObjArrayKlass
 60 //
 61 // Constructor for unloaded object array klasses.
 62 ciObjArrayKlass::ciObjArrayKlass(ciSymbol* array_name,
 63                                  ciKlass* base_element_klass,
 64                                  int dimension)
 65   : ciArrayKlass(array_name,
 66                  dimension, T_OBJECT) {
 67     _base_element_klass = base_element_klass;
 68     assert(_base_element_klass->is_instance_klass() ||
 69            _base_element_klass->is_type_array_klass(), "bad base klass");
 70     if (dimension == 1) {
 71       _element_klass = base_element_klass;
 72     } else {
 73       _element_klass = NULL;
 74     }
 75 }
 76 
 77 // ------------------------------------------------------------------
 78 // ciObjArrayKlass::element_klass
 79 //
 80 // What is the one-level element type of this array?
 81 ciKlass* ciObjArrayKlass::element_klass() {
 82   if (_element_klass == NULL) {
 83     assert(dimension() > 1, "_element_klass should not be NULL");
 84     // Produce the element klass.
 85     if (is_loaded()) {
 86       VM_ENTRY_MARK;
 87       Klass* element_Klass = get_ObjArrayKlass()->element_klass();
 88       _element_klass = CURRENT_THREAD_ENV->get_klass(element_Klass);
 89     } else {
 90       VM_ENTRY_MARK;
 91       // We are an unloaded array klass.  Attempt to fetch our
 92       // element klass by name.
 93       _element_klass = CURRENT_THREAD_ENV->get_klass_by_name_impl(
 94                           this,
 95                           constantPoolHandle(),
 96                           construct_array_name(base_element_klass()->name(),
 97                                                dimension() - 1),
 98                           false);
 99     }
100   }
101   return _element_klass;
102 }
103 
104 // ------------------------------------------------------------------
105 // ciObjArrayKlass::construct_array_name
106 //
107 // Build an array name from an element name and a dimension.
108 ciSymbol* ciObjArrayKlass::construct_array_name(ciSymbol* element_name,
109                                                 int dimension) {
110   EXCEPTION_CONTEXT;
111   int element_len = element_name->utf8_length();
112   int buflen = dimension + element_len + 3;  // '['+ + 'L'? + (element) + ';'? + '\0'
113   char* name = CURRENT_THREAD_ENV->name_buffer(buflen);
114   int pos = 0;
115   for ( ; pos < dimension; pos++) {
116     name[pos] = JVM_SIGNATURE_ARRAY;
117   }
118   Symbol* base_name_sym = element_name->get_symbol();
119 
120   if (Signature::is_array(base_name_sym) ||
121       Signature::has_envelope(base_name_sym)) {
122     strncpy(&name[pos], (char*)element_name->base(), element_len);
123     name[pos + element_len] = '\0';
124   } else {
125     name[pos++] = JVM_SIGNATURE_CLASS;
126     strncpy(&name[pos], (char*)element_name->base(), element_len);
127     name[pos + element_len] = JVM_SIGNATURE_ENDCLASS;
128     name[pos + element_len + 1] = '\0';
129   }
130   return ciSymbol::make(name);
131 }
132 
133 // ------------------------------------------------------------------
134 // ciObjArrayKlass::make_impl
135 //
136 // Implementation of make.
137 ciObjArrayKlass* ciObjArrayKlass::make_impl(ciKlass* element_klass) {
138 
139   if (element_klass->is_loaded()) {
140     EXCEPTION_CONTEXT;
141     // The element klass is loaded
142     Klass* array = element_klass->get_Klass()->array_klass(THREAD);
143     if (HAS_PENDING_EXCEPTION) {
144       CLEAR_PENDING_EXCEPTION;
145       CURRENT_THREAD_ENV->record_out_of_memory_failure();
146       return ciEnv::unloaded_ciobjarrayklass();
147     }
148     return CURRENT_THREAD_ENV->get_obj_array_klass(array);
149   }
150 
151   // The array klass was unable to be made or the element klass was
152   // not loaded.
153   ciSymbol* array_name = construct_array_name(element_klass->name(), 1);
154   if (array_name == ciEnv::unloaded_cisymbol()) {
155     return ciEnv::unloaded_ciobjarrayklass();
156   }
157   return
158     CURRENT_ENV->get_unloaded_klass(element_klass, array_name)
159                         ->as_obj_array_klass();
160 }
161 
162 // ------------------------------------------------------------------
163 // ciObjArrayKlass::make
164 //
165 // Make an array klass corresponding to the specified primitive type.
166 ciObjArrayKlass* ciObjArrayKlass::make(ciKlass* element_klass) {
167   GUARDED_VM_ENTRY(return make_impl(element_klass);)
168 }
169 
170 ciKlass* ciObjArrayKlass::exact_klass() {
171   ciType* base = base_element_type();
172   if (base->is_instance_klass()) {
173     ciInstanceKlass* ik = base->as_instance_klass();
174     if (ik->exact_klass() != NULL) {
175       return this;
176     }
177   } else if (base->is_primitive_type()) {
178     return this;
179   }
180   return NULL;
181 }