1 /*
   2  * Copyright (c) 1999, 2019, 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 #ifndef SHARE_CI_CIKLASS_HPP
  26 #define SHARE_CI_CIKLASS_HPP
  27 
  28 #include "ci/ciType.hpp"
  29 #include "oops/klass.hpp"
  30 
  31 // ciKlass
  32 //
  33 // This class and its subclasses represent Klass*s in the
  34 // HotSpot virtual machine.  In the vm, each Klass* contains an
  35 // embedded Klass object.  ciKlass is subclassed to explicitly
  36 // represent the kind of Klass embedded in the Klass*.  For
  37 // example, a Klass* with an embedded ObjArrayKlass object is
  38 // represented in the ciObject hierarchy by the class
  39 // ciObjArrayKlass.
  40 class ciKlass : public ciType {
  41   CI_PACKAGE_ACCESS
  42   friend class ciEnv;
  43   friend class ciField;
  44   friend class ciMethod;
  45   friend class ciMethodData;
  46   friend class ciObjArrayKlass;
  47   friend class ciValueArrayKlass;
  48   friend class ciReceiverTypeData;
  49 
  50 private:
  51   ciSymbol* _name;
  52   jint _layout_helper;
  53 
  54 protected:
  55   ciKlass(Klass* k, ciSymbol* name);
  56   ciKlass(ciSymbol* name, BasicType bt);
  57 
  58   Klass* get_Klass() const {
  59     Klass* k = (Klass*)_metadata;
  60     assert(k != NULL, "illegal use of unloaded klass");
  61     return k;
  62   }
  63 
  64   // Certain subklasses have an associated class loader.
  65   virtual oop loader()             { return NULL; }
  66   virtual jobject loader_handle()  { return NULL; }
  67 
  68   virtual oop protection_domain()             { return NULL; }
  69   virtual jobject protection_domain_handle()  { return NULL; }
  70 
  71   const char* type_string() { return "ciKlass"; }
  72 
  73   void print_impl(outputStream* st);
  74 
  75 public:
  76   ciKlass(Klass* k);
  77 
  78   // What is the name of this klass?
  79   ciSymbol* name() const { return _name; }
  80 
  81   // What is its layout helper value?
  82   jint layout_helper() { return _layout_helper; }
  83 
  84   bool is_subtype_of(ciKlass* klass);
  85   bool is_subclass_of(ciKlass* klass);
  86   juint super_depth();
  87   juint super_check_offset();
  88   ciKlass* super_of_depth(juint i);
  89   bool can_be_primary_super();
  90   static juint primary_super_limit() { return Klass::primary_super_limit(); }
  91 
  92   // Is this ciObject the ciInstanceKlass representing java.lang.Object()?
  93   virtual bool is_java_lang_Object() const  { return false; }
  94 
  95   // Get the shared parent of two klasses.
  96   ciKlass* least_common_ancestor(ciKlass* k);
  97 
  98   virtual bool is_interface() {
  99     return false;
 100   }
 101 
 102   virtual bool is_abstract() {
 103     return false;
 104   }
 105 
 106   // Does this type (array, class, interface) have no subtypes?
 107   virtual bool is_leaf_type() {
 108     return false;
 109   }
 110 
 111   virtual bool can_be_value_array_klass() {
 112     return is_java_lang_Object();
 113   }
 114 
 115   // Attempt to get a klass using this ciKlass's loader.
 116   ciKlass* find_klass(ciSymbol* klass_name);
 117   // Note:  To find a class from its name string, use ciSymbol::make,
 118   // but consider adding to vmSymbols.hpp instead.
 119 
 120   // Get the instance of java.lang.Class corresponding to this klass.
 121   ciInstance*            java_mirror();
 122 
 123   // Fetch Klass::modifier_flags.
 124   jint                   modifier_flags();
 125 
 126   // Fetch Klass::access_flags.
 127   jint                   access_flags();
 128 
 129   // What kind of ciObject is this?
 130   bool is_klass() const { return true; }
 131 
 132   virtual ciKlass* exact_klass() = 0;
 133 
 134   void print_name_on(outputStream* st);
 135 
 136   const char* external_name() const;
 137 };
 138 
 139 #endif // SHARE_CI_CIKLASS_HPP