1 /* 2 * Copyright 2000-2008 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 package sun.jvm.hotspot.types; 26 27 import sun.jvm.hotspot.debugger.*; 28 29 /** <P> This is the basic interface which describes a field in a C/C++ 30 data structure or a Java object. </P> 31 32 <P> The accessors in this class are designed to allow manual 33 coercion of the data within the field, which is often necessary 34 when interfacing with C programs. Therefore, the accessors here do 35 not perform any type checking. Specializations of the Field 36 interface, such as JByteField, provide getValue() methods which 37 both perform type checking and return the appropriate specialized 38 type. </P> 39 40 <P> See @see CIntegerType for a description of why all C integer 41 types are bundled into the category "CIntegerType". </P> 42 43 <P> As an example, coercing a pointer field into an int can be 44 done in the following fashion (assuming the application has 45 registered an integer type in the type database called 46 "intptr_t"): </P> 47 48 <PRE> 49 { 50 ... 51 Address myObject = ...; 52 CIntegerType intptr_tType = (CIntegerType) db.lookupType("intptr_t"); 53 long addrVal = field.getCInteger(myObject, intptr_tType); 54 ... 55 } 56 </PRE> 57 58 FIXME: among other things, this interface is not sufficient to 59 describe fields which are themselves arrays (like symbolOop's 60 jbyte _body[1]). */ 61 public interface Field { 62 /** Get the name of this field */ 63 public String getName(); 64 65 /** Get the type of this field */ 66 public Type getType(); 67 68 /** Get the size, in bytes, of this field. Used for manual data 69 structure traversal where necessary. */ 70 public long getSize(); 71 72 /** Is this a static field? */ 73 public boolean isStatic(); 74 75 /** The offset of this field, in bytes, in its containing data 76 structure, if nonstatic. If this is a static field, throws a 77 WrongTypeException. */ 78 public long getOffset() throws WrongTypeException; 79 80 /** The address of this field, if it is a static field. If this is a 81 nonstatic field, throws a WrongTypeException. */ 82 public Address getStaticFieldAddress() throws WrongTypeException; 83 84 /** <P> These accessors require that the field be nonstatic; 85 otherwise, a WrongTypeException will be thrown. Note that type 86 checking is not performed by these accessors in order to allow 87 manual type coercion of field data. For better protection when 88 accessing primitive fields, use the get(Type)Field accessors in 89 Type.java. </P> 90 91 <P> NOTE that the Address passed in to these routines may, in 92 fact, be an OopHandle. Specifically, in a reflective system, 93 dereferencing operations applied to the OopHandle must be 94 performed atomically with respect to GC. </P> 95 96 <P> See @see CIntegerType for a description of why all C integer 97 types are bundled into the category "CIntegerType". </P> 98 */ 99 public boolean getJBoolean (Address addr) throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 100 public byte getJByte (Address addr) throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 101 public char getJChar (Address addr) throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 102 public short getJShort (Address addr) throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 103 public int getJInt (Address addr) throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 104 public long getJLong (Address addr) throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 105 public float getJFloat (Address addr) throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 106 public double getJDouble (Address addr) throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 107 public long getCInteger (Address addr, CIntegerType type) 108 throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 109 public Address getAddress (Address addr) throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 110 public OopHandle getOopHandle(Address addr) 111 throws UnmappedAddressException, UnalignedAddressException, WrongTypeException, NotInHeapException; 112 public OopHandle getNarrowOopHandle(Address addr) 113 throws UnmappedAddressException, UnalignedAddressException, WrongTypeException, NotInHeapException; 114 115 /** <P> These accessors require that the field be static; otherwise, 116 a WrongTypeException will be thrown. Note that type checking is 117 not performed by these accessors in order to allow manual type 118 coercion of field data. For better protection when accessing 119 primitive fields, use the get(Type)Field accessors in 120 Type.java. </P> 121 122 <P> NOTE that the Address passed in to these routines may, in 123 fact, be an OopHandle. Specifically, in a reflective system, 124 dereferencing operations applied to the OopHandle must be 125 performed atomically with respect to GC. </P> 126 127 <P> See @see CIntegerType for a description of why all C integer 128 types are bundled into the category "CIntegerType". </P> 129 */ 130 public boolean getJBoolean () throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 131 public byte getJByte () throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 132 public char getJChar () throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 133 public float getJFloat () throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 134 public double getJDouble () throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 135 public int getJInt () throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 136 public long getJLong () throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 137 public short getJShort () throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 138 public long getCInteger (CIntegerType type) 139 throws UnmappedAddressException, UnalignedAddressException, WrongTypeException; 140 public Address getAddress () throws UnmappedAddressException, UnalignedAddressException; 141 public OopHandle getOopHandle() 142 throws UnmappedAddressException, UnalignedAddressException, NotInHeapException; 143 public OopHandle getNarrowOopHandle() 144 throws UnmappedAddressException, UnalignedAddressException, NotInHeapException; 145 }