1 /*
   2  * Copyright (c) 1999, 2017, 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 
  32 // ciObjArrayKlass
  33 //
  34 // This class represents a Klass* in the HotSpot virtual machine
  35 // whose Klass part is an ObjArrayKlass.
  36 
  37 // ------------------------------------------------------------------
  38 // ciObjArrayKlass::ciObjArrayKlass
  39 //
  40 // Constructor for loaded object array klasses.
  41 ciObjArrayKlass::ciObjArrayKlass(Klass* k) : ciArrayKlass(k) {
  42   assert(get_Klass()->is_objArray_klass(), "wrong type");
  43   Klass* element_Klass = get_ObjArrayKlass()->bottom_klass();
  44   _base_element_klass = CURRENT_ENV->get_klass(element_Klass);
  45   assert(_base_element_klass->is_instance_klass() ||
  46          _base_element_klass->is_type_array_klass(), "bad base klass");
  47   if (dimension() == 1) {
  48     _element_klass = _base_element_klass;
  49   } else {
  50     _element_klass = NULL;
  51   }
  52   if (!ciObjectFactory::is_initialized()) {
  53     assert(_element_klass->is_java_lang_Object(), "only arrays of object are shared");
  54   }
  55 }
  56 
  57 // ------------------------------------------------------------------
  58 // ciObjArrayKlass::ciObjArrayKlass
  59 //
  60 // Constructor for unloaded object array klasses.
  61 ciObjArrayKlass::ciObjArrayKlass(ciSymbol* array_name,
  62                                  ciKlass* base_element_klass,
  63                                  int dimension)
  64   : ciArrayKlass(array_name,
  65                  dimension, T_OBJECT) {
  66     _base_element_klass = base_element_klass;
  67     assert(_base_element_klass->is_instance_klass() ||
  68            _base_element_klass->is_type_array_klass() ||
  69            _base_element_klass->is_value_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 
 113   Symbol* base_name_sym = element_name->get_symbol();
 114   assert(base_name_sym->char_at(0) != 'Q', "unloaded array klass element should not have Q-type");
 115   char* name;
 116 
 117   if (base_name_sym->char_at(0) == '[' ||
 118       (base_name_sym->char_at(0) == 'L' &&  // watch package name 'Lxx'
 119        base_name_sym->char_at(element_len-1) == ';')) {
 120 
 121     int new_len = element_len + dimension + 1; // for the ['s and '\0'
 122     name = CURRENT_THREAD_ENV->name_buffer(new_len);
 123 
 124     int pos = 0;
 125     for ( ; pos < dimension; pos++) {
 126       name[pos] = '[';
 127     }
 128     strncpy(name+pos, (char*)element_name->base(), element_len);
 129     name[new_len-1] = '\0';
 130   } else {
 131     int new_len =   3                       // for L, ;, and '\0'
 132                   + dimension               // for ['s
 133                   + element_len;
 134 
 135     name = CURRENT_THREAD_ENV->name_buffer(new_len);
 136     int pos = 0;
 137     for ( ; pos < dimension; pos++) {
 138       name[pos] = '[';
 139     }
 140     name[pos++] = 'L';
 141     strncpy(name+pos, (char*)element_name->base(), element_len);
 142     name[new_len-2] = ';';
 143     name[new_len-1] = '\0';
 144   }
 145   return ciSymbol::make(name);
 146 }
 147 
 148 // ------------------------------------------------------------------
 149 // ciObjArrayKlass::make_impl
 150 //
 151 // Implementation of make.
 152 ciObjArrayKlass* ciObjArrayKlass::make_impl(ciKlass* element_klass, bool never_null) {
 153   if (element_klass->is_loaded()) {
 154     EXCEPTION_CONTEXT;
 155     // The element klass is loaded
 156     ArrayStorageProperties props = never_null ? ArrayStorageProperties::flattened_and_null_free : ArrayStorageProperties::empty;
 157     Klass* array = element_klass->get_Klass()->array_klass(props, THREAD);
 158     if (element_klass->is_valuetype()) {
 159       assert(!ObjArrayKlass::cast(array)->storage_properties().is_flattened(), "should not be flattened");
 160       assert(ObjArrayKlass::cast(array)->storage_properties().is_null_free() == never_null, "wrong nullability storage property");
 161     }
 162     if (HAS_PENDING_EXCEPTION) {
 163       CLEAR_PENDING_EXCEPTION;
 164       CURRENT_THREAD_ENV->record_out_of_memory_failure();
 165       return ciEnv::unloaded_ciobjarrayklass();
 166     }
 167     return CURRENT_THREAD_ENV->get_obj_array_klass(array);
 168   }
 169 
 170   // The array klass was unable to be made or the element klass was not loaded.
 171   ciSymbol* array_name = construct_array_name(element_klass->name(), 1);
 172   if (array_name == ciEnv::unloaded_cisymbol()) {
 173     return ciEnv::unloaded_ciobjarrayklass();
 174   }
 175   return
 176     CURRENT_ENV->get_unloaded_klass(element_klass, array_name)
 177                         ->as_obj_array_klass();
 178 }
 179 
 180 // ------------------------------------------------------------------
 181 // ciObjArrayKlass::make
 182 //
 183 // Make an array klass corresponding to the specified primitive type.
 184 ciObjArrayKlass* ciObjArrayKlass::make(ciKlass* element_klass, bool never_null) {
 185   GUARDED_VM_ENTRY(return make_impl(element_klass, never_null);)
 186 }
 187 
 188 ciKlass* ciObjArrayKlass::exact_klass() {
 189   ciType* base = base_element_type();
 190   if (base->is_instance_klass()) {
 191     ciInstanceKlass* ik = base->as_instance_klass();
 192     if (ik->exact_klass() != NULL) {
 193       return this;
 194     }
 195   } else if (base->is_primitive_type()) {
 196     return this;
 197   }
 198   return NULL;
 199 }