duke@435: /*
coleenp@4037:  * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #ifndef SHARE_VM_CI_CIOBJECT_HPP
stefank@2314: #define SHARE_VM_CI_CIOBJECT_HPP
stefank@2314: 
coleenp@4037: #include "ci/ciBaseObject.hpp"
stefank@2314: #include "ci/ciClassList.hpp"
stefank@2314: #include "memory/allocation.hpp"
stefank@2314: #include "runtime/handles.hpp"
stefank@2314: #include "runtime/jniHandles.hpp"
stefank@2314: 
duke@435: // ciObject
duke@435: //
duke@435: // This class represents an oop in the HotSpot virtual machine.
duke@435: // Its subclasses are structured in a hierarchy which mirrors
duke@435: // an aggregate of the VM's oop and klass hierarchies (see
duke@435: // oopHierarchy.hpp).  Each instance of ciObject holds a handle
duke@435: // to a corresponding oop on the VM side and provides routines
duke@435: // for accessing the information in its oop.  By using the ciObject
duke@435: // hierarchy for accessing oops in the VM, the compiler ensures
duke@435: // that it is safe with respect to garbage collection; that is,
duke@435: // GC and compilation can proceed independently without
duke@435: // interference.
duke@435: //
duke@435: // Within the VM, the oop and klass hierarchies are separate.
duke@435: // The compiler interface does not preserve this separation --
coleenp@4037: // the distinction between `Klass*' and `Klass' are not
duke@435: // reflected in the interface and instead the Klass hierarchy
duke@435: // is directly modeled as the subclasses of ciKlass.
coleenp@4037: class ciObject : public ciBaseObject {
duke@435:   CI_PACKAGE_ACCESS
duke@435:   friend class ciEnv;
duke@435: 
duke@435: private:
duke@435:   // A JNI handle referring to an oop in the VM.  This
duke@435:   // handle may, in a small set of cases, correctly be NULL.
duke@435:   jobject  _handle;
duke@435:   ciKlass* _klass;
duke@435: 
duke@435: protected:
duke@435:   ciObject();
duke@435:   ciObject(oop o);
duke@435:   ciObject(Handle h);
duke@435:   ciObject(ciKlass* klass);
duke@435: 
duke@435:   jobject      handle()  const { return _handle; }
duke@435:   // Get the VM oop that this object holds.
duke@435:   oop get_oop() const {
duke@435:     assert(_handle != NULL, "null oop");
duke@435:     return JNIHandles::resolve_non_null(_handle);
duke@435:   }
duke@435: 
coleenp@4037:   void init_flags_from(oop x);
duke@435: 
duke@435:   // Virtual behavior of the print() method.
duke@435:   virtual void print_impl(outputStream* st) {}
duke@435: 
duke@435:   virtual const char* type_string() { return "ciObject"; }
duke@435: 
duke@435: public:
duke@435:   // The klass of this ciObject.
duke@435:   ciKlass* klass();
duke@435: 
duke@435:   // Are two ciObjects equal?
duke@435:   bool equals(ciObject* obj);
duke@435: 
duke@435:   // A hash value for the convenience of compilers.
duke@435:   int hash();
duke@435: 
jrose@1424:   // Tells if this oop has an encoding as a constant.
kvn@2933:   // True if is_perm is true.
jrose@1424:   // Also true if ScavengeRootsInCode is non-zero.
duke@435:   // If it does not have an encoding, the compiler is responsible for
duke@435:   // making other arrangements for dealing with the oop.
jrose@1424:   // See ciEnv::make_array
jrose@1424:   bool can_be_constant();
jrose@1424: 
jrose@1424:   // Tells if this oop should be made a constant.
kvn@2933:   // True if is_perm is true or ScavengeRootsInCode > 1.
jrose@1424:   bool should_be_constant();
duke@435: 
jrose@1424:   // Might this object possibly move during a scavenge operation?
jrose@1424:   // If the answer is true and ScavengeRootsInCode==0, the oop cannot be embedded in code.
jrose@1424:   bool is_scavengable() { return (_ident & SCAVENGABLE_FLAG) != 0; }
jrose@1424: 
duke@435:   // The address which the compiler should embed into the
duke@435:   // generated code to represent this oop.  This address
duke@435:   // is not the true address of the oop -- it will get patched
duke@435:   // during nmethod creation.
duke@435:   //
duke@435:   // Usage note: no address arithmetic allowed.  Oop must
duke@435:   // be registered with the oopRecorder.
jrose@1424:   jobject constant_encoding();
duke@435: 
coleenp@4037:   virtual bool is_object() const            { return true; }
coleenp@4037: 
duke@435:   // What kind of ciObject is this?
twisti@3969:   virtual bool is_null_object()       const { return false; }
twisti@3969:   virtual bool is_call_site()         const { return false; }
twisti@3969:   virtual bool is_cpcache()           const { return false; }
duke@435:   virtual bool is_instance()                { return false; }
twisti@3969:   virtual bool is_member_name()       const { return false; }
twisti@3969:   virtual bool is_method_handle()     const { return false; }
twisti@4133:   virtual bool is_method_type()       const { return false; }
duke@435:   virtual bool is_array()                   { return false; }
duke@435:   virtual bool is_obj_array()               { return false; }
duke@435:   virtual bool is_type_array()              { return false; }
duke@435: 
duke@435:   // Is this a type or value which has no associated class?
duke@435:   // It is true of primitive types and null objects.
duke@435:   virtual bool is_classless() const         { return false; }
minqi@4267:   virtual void dump_replay_data(outputStream* st) { /* do nothing */ }
duke@435: 
coleenp@4037:   // Note: some ciObjects refer to oops which have yet to be created.
coleenp@4037:   // We refer to these as "unloaded".  Specifically, there are
coleenp@4037:   // unloaded instances of java.lang.Class,
coleenp@4037:   // java.lang.invoke.MethodHandle, and java.lang.invoke.MethodType.
coleenp@4037:   // By convention the ciNullObject is considered loaded, and
coleenp@4037:   // primitive types are considered loaded.
duke@435:   bool is_loaded() const {
duke@435:     return handle() != NULL || is_classless();
duke@435:   }
duke@435: 
duke@435:   // Subclass casting with assertions.
twisti@4133:   ciNullObject* as_null_object() {
duke@435:     assert(is_null_object(), "bad cast");
duke@435:     return (ciNullObject*)this;
duke@435:   }
twisti@4133:   ciCallSite* as_call_site() {
twisti@1573:     assert(is_call_site(), "bad cast");
twisti@4133:     return (ciCallSite*)this;
twisti@1573:   }
twisti@4133:   ciInstance* as_instance() {
duke@435:     assert(is_instance(), "bad cast");
duke@435:     return (ciInstance*)this;
duke@435:   }
twisti@4133:   ciMemberName* as_member_name() {
twisti@3969:     assert(is_member_name(), "bad cast");
twisti@3969:     return (ciMemberName*)this;
twisti@3969:   }
twisti@4133:   ciMethodHandle* as_method_handle() {
twisti@1573:     assert(is_method_handle(), "bad cast");
twisti@4133:     return (ciMethodHandle*)this;
twisti@1573:   }
twisti@4133:   ciMethodType* as_method_type() {
twisti@4133:     assert(is_method_type(), "bad cast");
twisti@4133:     return (ciMethodType*)this;
twisti@4133:   }
twisti@4133:   ciArray* as_array() {
duke@435:     assert(is_array(), "bad cast");
duke@435:     return (ciArray*)this;
duke@435:   }
twisti@4133:   ciObjArray* as_obj_array() {
duke@435:     assert(is_obj_array(), "bad cast");
duke@435:     return (ciObjArray*)this;
duke@435:   }
twisti@4133:   ciTypeArray* as_type_array() {
duke@435:     assert(is_type_array(), "bad cast");
duke@435:     return (ciTypeArray*)this;
duke@435:   }
duke@435: 
duke@435:   // Print debugging output about this ciObject.
twisti@3969:   void print(outputStream* st);
twisti@3969:   void print() { print(tty); }  // GDB cannot handle default arguments
duke@435: 
duke@435:   // Print debugging output about the oop this ciObject represents.
duke@435:   void print_oop(outputStream* st = tty);
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_CI_CIOBJECT_HPP