1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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24
25#ifndef SHARE_CI_CIOBJECT_HPP
26#define SHARE_CI_CIOBJECT_HPP
27
28#include "ci/ciBaseObject.hpp"
29#include "ci/ciClassList.hpp"
30#include "runtime/handles.hpp"
31#include "runtime/jniHandles.hpp"
32
33// ciObject
34//
35// This class represents an oop in the HotSpot virtual machine.
36// Its subclasses are structured in a hierarchy which mirrors
37// an aggregate of the VM's oop and klass hierarchies (see
38// oopHierarchy.hpp). Each instance of ciObject holds a handle
39// to a corresponding oop on the VM side and provides routines
40// for accessing the information in its oop. By using the ciObject
41// hierarchy for accessing oops in the VM, the compiler ensures
42// that it is safe with respect to garbage collection; that is,
43// GC and compilation can proceed independently without
44// interference.
45//
46// Within the VM, the oop and klass hierarchies are separate.
47// The compiler interface does not preserve this separation --
48// the distinction between `Klass*' and `Klass' are not
49// reflected in the interface and instead the Klass hierarchy
50// is directly modeled as the subclasses of ciKlass.
51class ciObject : public ciBaseObject {
52 CI_PACKAGE_ACCESS
53 friend class ciEnv;
54
55private:
56 // A JNI handle referring to an oop in the VM. This
57 // handle may, in a small set of cases, correctly be NULL.
58 jobject _handle;
59 ciKlass* _klass;
60
61protected:
62 ciObject();
63 ciObject(oop o);
64 ciObject(Handle h);
65 ciObject(ciKlass* klass);
66
67 jobject handle() const { return _handle; }
68 // Get the VM oop that this object holds.
69 oop get_oop() const;
70
71 // Virtual behavior of the print() method.
72 virtual void print_impl(outputStream* st) {}
73
74 virtual const char* type_string() { return "ciObject"; }
75
76public:
77 // The klass of this ciObject.
78 ciKlass* klass();
79
80 // Are two ciObjects equal?
81 bool equals(ciObject* obj);
82
83 // A hash value for the convenience of compilers.
84 int hash();
85
86 // Tells if this oop should be made a constant.
87 bool should_be_constant();
88
89 // The address which the compiler should embed into the
90 // generated code to represent this oop. This address
91 // is not the true address of the oop -- it will get patched
92 // during nmethod creation.
93 //
94 // Usage note: no address arithmetic allowed. Oop must
95 // be registered with the oopRecorder.
96 jobject constant_encoding();
97
98 virtual bool is_object() const { return true; }
99
100 // What kind of ciObject is this?
101 virtual bool is_null_object() const { return false; }
102 virtual bool is_call_site() const { return false; }
103 virtual bool is_instance() { return false; }
104 virtual bool is_member_name() const { return false; }
105 virtual bool is_method_handle() const { return false; }
106 virtual bool is_method_type() const { return false; }
107 virtual bool is_array() { return false; }
108 virtual bool is_obj_array() { return false; }
109 virtual bool is_type_array() { return false; }
110
111 // Is this a type or value which has no associated class?
112 // It is true of primitive types and null objects.
113 virtual bool is_classless() const { return false; }
114 virtual void dump_replay_data(outputStream* st) { /* do nothing */ }
115
116 // Note: some ciObjects refer to oops which have yet to be created.
117 // We refer to these as "unloaded". Specifically, there are
118 // unloaded instances of java.lang.Class,
119 // java.lang.invoke.MethodHandle, and java.lang.invoke.MethodType.
120 // By convention the ciNullObject is considered loaded, and
121 // primitive types are considered loaded.
122 bool is_loaded() const {
123 return handle() != NULL || is_classless();
124 }
125
126 // Subclass casting with assertions.
127 ciNullObject* as_null_object() {
128 assert(is_null_object(), "bad cast");
129 return (ciNullObject*)this;
130 }
131 ciCallSite* as_call_site() {
132 assert(is_call_site(), "bad cast");
133 return (ciCallSite*)this;
134 }
135 ciInstance* as_instance() {
136 assert(is_instance(), "bad cast");
137 return (ciInstance*)this;
138 }
139 ciMemberName* as_member_name() {
140 assert(is_member_name(), "bad cast");
141 return (ciMemberName*)this;
142 }
143 ciMethodHandle* as_method_handle() {
144 assert(is_method_handle(), "bad cast");
145 return (ciMethodHandle*)this;
146 }
147 ciMethodType* as_method_type() {
148 assert(is_method_type(), "bad cast");
149 return (ciMethodType*)this;
150 }
151 ciArray* as_array() {
152 assert(is_array(), "bad cast");
153 return (ciArray*)this;
154 }
155 ciObjArray* as_obj_array() {
156 assert(is_obj_array(), "bad cast");
157 return (ciObjArray*)this;
158 }
159 ciTypeArray* as_type_array() {
160 assert(is_type_array(), "bad cast");
161 return (ciTypeArray*)this;
162 }
163
164 // Print debugging output about this ciObject.
165 void print(outputStream* st);
166 void print() { print(tty); } // GDB cannot handle default arguments
167
168 // Print debugging output about the oop this ciObject represents.
169 void print_oop(outputStream* st = tty);
170};
171
172#endif // SHARE_CI_CIOBJECT_HPP
173