1 /* 2 * Copyright (c) 1999, 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 "ci/ciInstanceKlass.hpp" 26 #include "ci/ciObjArrayKlass.hpp" 27 #include "ci/ciSymbol.hpp" 28 #include "ci/ciUtilities.inline.hpp" 29 #include "oops/inlineKlass.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 = nullptr; 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() || 70 _base_element_klass->is_flat_array_klass(), "bad base klass"); 71 if (dimension == 1) { 72 _element_klass = base_element_klass; 73 } else { 74 _element_klass = nullptr; 75 } 76 } 77 78 // ------------------------------------------------------------------ 79 // ciObjArrayKlass::element_klass 80 // 81 // What is the one-level element type of this array? 82 ciKlass* ciObjArrayKlass::element_klass() { 83 if (_element_klass == nullptr) { 84 assert(dimension() > 1, "_element_klass should not be null"); 85 // Produce the element klass. 86 if (is_loaded()) { 87 VM_ENTRY_MARK; 88 Klass* element_Klass = get_ObjArrayKlass()->element_klass(); 89 _element_klass = CURRENT_THREAD_ENV->get_klass(element_Klass); 90 } else { 91 VM_ENTRY_MARK; 92 // We are an unloaded array klass. Attempt to fetch our 93 // element klass by name. 94 _element_klass = CURRENT_THREAD_ENV->get_klass_by_name_impl( 95 this, 96 constantPoolHandle(), 97 construct_array_name(base_element_klass()->name(), 98 dimension() - 1), 99 false); 100 } 101 } 102 return _element_klass; 103 } 104 105 // ------------------------------------------------------------------ 106 // ciObjArrayKlass::construct_array_name 107 // 108 // Build an array name from an element name and a dimension. 109 ciSymbol* ciObjArrayKlass::construct_array_name(ciSymbol* element_name, 110 int dimension) { 111 EXCEPTION_CONTEXT; 112 int element_len = element_name->utf8_length(); 113 int buflen = dimension + element_len + 3; // '['+ + 'L'? + (element) + ';'? + '\0' 114 char* name = CURRENT_THREAD_ENV->name_buffer(buflen); 115 int pos = 0; 116 for ( ; pos < dimension; pos++) { 117 name[pos] = JVM_SIGNATURE_ARRAY; 118 } 119 Symbol* base_name_sym = element_name->get_symbol(); 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 if (element_klass->is_loaded()) { 139 EXCEPTION_CONTEXT; 140 // The element klass is loaded 141 Klass* array = element_klass->get_Klass()->array_klass(THREAD); 142 if (HAS_PENDING_EXCEPTION) { 143 CLEAR_PENDING_EXCEPTION; 144 CURRENT_THREAD_ENV->record_out_of_memory_failure(); 145 return ciEnv::unloaded_ciobjarrayklass(); 146 } 147 return CURRENT_THREAD_ENV->get_obj_array_klass(array); 148 } 149 150 // The array klass was unable to be made or the element klass was not loaded. 151 ciSymbol* array_name = construct_array_name(element_klass->name(), 1); 152 if (array_name == ciEnv::unloaded_cisymbol()) { 153 return ciEnv::unloaded_ciobjarrayklass(); 154 } 155 return 156 CURRENT_ENV->get_unloaded_klass(element_klass, array_name) 157 ->as_obj_array_klass(); 158 } 159 160 // ------------------------------------------------------------------ 161 // ciObjArrayKlass::make 162 // 163 // Make an array klass corresponding to the specified primitive type. 164 ciObjArrayKlass* ciObjArrayKlass::make(ciKlass* element_klass) { 165 GUARDED_VM_ENTRY(return make_impl(element_klass);) 166 } 167 168 ciObjArrayKlass* ciObjArrayKlass::make(ciKlass* element_klass, int dims) { 169 ciKlass* klass = element_klass; 170 for (int i = 0; i < dims; i++) { 171 klass = ciObjArrayKlass::make(klass); 172 } 173 return klass->as_obj_array_klass(); 174 } 175 176 ciKlass* ciObjArrayKlass::exact_klass() { 177 if (!is_loaded()) { 178 return nullptr; 179 } 180 ciType* base = base_element_type(); 181 if (base->is_instance_klass()) { 182 ciInstanceKlass* ik = base->as_instance_klass(); 183 // Even though MyValue is final, [LMyValue is only exact if the array 184 // is null-free due to null-free [LMyValue <: null-able [LMyValue. 185 if (ik->is_inlinetype() && !is_elem_null_free()) { 186 return nullptr; 187 } 188 if (ik->exact_klass() != nullptr) { 189 return this; 190 } 191 } else if (base->is_primitive_type()) { 192 return this; 193 } 194 return nullptr; 195 }