1 /*
  2  * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  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
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 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 ciSignature;
 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 != nullptr, "illegal use of unloaded klass");
 61     return k;
 62   }
 63 
 64   // Certain subklasses have an associated class loader.
 65   virtual oop loader()             { return nullptr; }
 66   virtual jobject loader_handle()  { return nullptr; }
 67 
 68   virtual oop protection_domain()             { return nullptr; }
 69   virtual jobject protection_domain_handle()  { return nullptr; }
 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   static juint primary_super_limit() { return Klass::primary_super_limit(); }
 90 
 91   // Is this ciObject the ciInstanceKlass representing java.lang.Object()?
 92   virtual bool is_java_lang_Object() const  { return false; }
 93 
 94   // Get the shared parent of two klasses.
 95   ciKlass* least_common_ancestor(ciKlass* k);
 96 
 97   virtual bool is_interface() {
 98     return false;
 99   }
100 
101   virtual bool is_abstract() {
102     return false;
103   }
104 
105   // Does this type (array, class, interface) have no subtypes?
106   virtual bool is_leaf_type() {
107     return false;
108   }
109 
110   // Attempt to get a klass using this ciKlass's loader.
111   ciKlass* find_klass(ciSymbol* klass_name);
112   // Note:  To find a class from its name string, use ciSymbol::make,
113   // but consider adding to vmSymbols.hpp instead.
114 
115   // Get the instance of java.lang.Class corresponding to this klass.
116   ciInstance*            java_mirror();
117 
118   // Fetch Klass::modifier_flags.
119   jint                   modifier_flags();
120 
121   // Fetch Klass::access_flags.
122   jint                   access_flags();
123 
124   // What kind of ciObject is this?
125   bool is_klass() const { return true; }
126 
127   virtual ciKlass* exact_klass() = 0;
128 
129   void print_name_on(outputStream* st);
130 
131   const char* external_name() const;
132 
133   juint prototype_header_offset();
134   uintptr_t prototype_header();
135 };
136 
137 #endif // SHARE_CI_CIKLASS_HPP