1 /*
 2  * Copyright (c) 2011, 2024, 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_OOPS_METADATA_HPP
26 #define SHARE_OOPS_METADATA_HPP
27 
28 #include "utilities/exceptions.hpp"
29 #include "utilities/globalDefinitions.hpp"
30 #include "utilities/ostream.hpp"
31 
32 // This is the base class for an internal Class related metadata
33 class Metadata : public MetaspaceObj {
34   // Debugging hook to check that the metadata has not been deleted.
35   NOT_PRODUCT(int _valid;)
36  public:
37   NOT_PRODUCT(Metadata() : _valid(0) {})
38   NOT_PRODUCT(bool is_valid() const { return _valid == 0; })
39 
40   int identity_hash()                { return (int)(uintptr_t)this; }
41 
42   virtual bool is_metadata()           const { return true; }
43   virtual bool is_klass()              const { return false; }
44   virtual bool is_method()             const { return false; }
45   virtual bool is_methodData()         const { return false; }
46   virtual bool is_constantPool()       const { return false; }
47   virtual int  size()                  const = 0;
48   virtual MetaspaceObj::Type type()    const = 0;
49   virtual const char* internal_name()  const = 0;
50   virtual void metaspace_pointers_do(MetaspaceClosure* iter) = 0;
51 
52   void print()       const;
53   void print_value() const;
54 
55   static void print_value_on_maybe_null(outputStream* st, const Metadata* m) {
56     if (nullptr == m)
57       st->print("null");
58     else
59       m->print_value_on(st);
60   }
61 
62   virtual void print_on(outputStream* st) const;       // First level print
63   virtual void print_value_on(outputStream* st) const = 0; // Second level print
64 
65   char* print_value_string() const;
66 
67   // Used to keep metadata alive during class redefinition
68   // Can't assert because is called for delete functions (as an assert)
69   virtual bool on_stack() const { return false; }
70   virtual void set_on_stack(const bool value);
71 
72   // Set on_stack bit, so that the metadata is not cleared
73   // during class redefinition.  This is a virtual call because only methods
74   // and constant pools need to be set, but someday instanceKlasses might also.
75   static void mark_on_stack(Metadata* m) { m->set_on_stack(true); }
76 };
77 
78 template <typename M>
79 static void print_on_maybe_null(outputStream* st, const char* str, const M* m) {
80   if (nullptr != m) {
81     st->print_raw(str);
82     m->print_value_on(st);
83     st->cr();
84   }
85 }
86 
87 #endif // SHARE_OOPS_METADATA_HPP