1 /*
   2  * Copyright (c) 1999, 2015, 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/ciArray.hpp"
  27 #include "ci/ciArrayKlass.hpp"
  28 #include "ci/ciConstant.hpp"
  29 #include "ci/ciKlass.hpp"
  30 #include "ci/ciUtilities.hpp"
  31 #include "oops/objArrayOop.inline.hpp"
  32 #include "oops/oop.inline.hpp"
  33 #include "oops/typeArrayOop.hpp"
  34 
  35 // ciArray
  36 //
  37 // This class represents an arrayOop in the HotSpot virtual
  38 // machine.
  39 static BasicType fixup_element_type(BasicType bt) {
  40   if (bt == T_ARRAY)    return T_OBJECT;
  41   if (bt == T_BOOLEAN)  return T_BYTE;
  42   return bt;
  43 }
  44 
  45 ciConstant ciArray::element_value_impl(BasicType elembt,
  46                                        arrayOop ary,
  47                                        int index) {
  48   if (ary == NULL)
  49     return ciConstant();
  50   assert(ary->is_array(), "");
  51   if (index < 0 || index >= ary->length())
  52     return ciConstant();
  53   ArrayKlass* ak = (ArrayKlass*) ary->klass();
  54   BasicType abt = ak->element_type();
  55   if (fixup_element_type(elembt) !=
  56       fixup_element_type(abt))
  57     return ciConstant();
  58   switch (elembt) {
  59   case T_ARRAY:
  60   case T_OBJECT:
  61     {
  62       assert(ary->is_objArray(), "");
  63       objArrayOop objary = (objArrayOop) ary;
  64       oop elem = objary->obj_at(index);
  65       ciEnv* env = CURRENT_ENV;
  66       ciObject* box = env->get_object(elem);
  67       return ciConstant(T_OBJECT, box);
  68     }
  69   }
  70   assert(ary->is_typeArray(), "");
  71   typeArrayOop tary = (typeArrayOop) ary;
  72   jint value = 0;
  73   switch (elembt) {
  74   case T_LONG:          return ciConstant(tary->long_at(index));
  75   case T_FLOAT:         return ciConstant(tary->float_at(index));
  76   case T_DOUBLE:        return ciConstant(tary->double_at(index));
  77   default:              return ciConstant();
  78   case T_BYTE:          value = tary->byte_at(index);           break;
  79   case T_BOOLEAN:       value = tary->byte_at(index) & 1;       break;
  80   case T_SHORT:         value = tary->short_at(index);          break;
  81   case T_CHAR:          value = tary->char_at(index);           break;
  82   case T_INT:           value = tary->int_at(index);            break;
  83   }
  84   return ciConstant(elembt, value);
  85 }
  86 
  87 // ------------------------------------------------------------------
  88 // ciArray::element_value
  89 //
  90 // Current value of an element.
  91 // Returns T_ILLEGAL if there is no element at the given index.
  92 ciConstant ciArray::element_value(int index) {
  93   BasicType elembt = element_basic_type();
  94   GUARDED_VM_ENTRY(
  95     return element_value_impl(elembt, get_arrayOop(), index);
  96   )
  97 }
  98 
  99 // ------------------------------------------------------------------
 100 // ciArray::element_value_by_offset
 101 //
 102 // Current value of an element at the specified offset.
 103 // Returns T_ILLEGAL if there is no element at the given offset.
 104 ciConstant ciArray::element_value_by_offset(intptr_t element_offset) {
 105   BasicType elembt = element_basic_type();
 106   intptr_t shift  = exact_log2(type2aelembytes(elembt));
 107   intptr_t header = arrayOopDesc::base_offset_in_bytes(elembt);
 108   intptr_t index = (element_offset - header) >> shift;
 109   intptr_t offset = header + ((intptr_t)index << shift);
 110   if (offset != element_offset || index != (jint)index || index < 0 || index >= length()) {
 111     return ciConstant();
 112   }
 113   return element_value((jint) index);
 114 }
 115 
 116 // ------------------------------------------------------------------
 117 // ciArray::print_impl
 118 //
 119 // Implementation of the print method.
 120 void ciArray::print_impl(outputStream* st) {
 121   st->print(" length=%d type=", length());
 122   klass()->print(st);
 123 }