1 /* 2 * Copyright (c) 2000, 2011, 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 package sun.jvm.hotspot.types; 26 27 import java.util.Iterator; 28 import sun.jvm.hotspot.debugger.Address; 29 30 public interface TypeDataBase { 31 /** Equivalent to lookupType(cTypeName, true) */ lookupType(String cTypeName)32 public Type lookupType(String cTypeName); 33 34 /** For simplicity of the initial implementation, this is not 35 guaranteed to work for primitive types. If throwException is 36 true, throws an (unspecified) run-time exception if the type is 37 not found. */ lookupType(String cTypeName, boolean throwException)38 public Type lookupType(String cTypeName, boolean throwException); 39 40 /** Equivalent to lookupIntConstant(constantName, true) */ lookupIntConstant(String constantName)41 public Integer lookupIntConstant(String constantName); 42 43 /* For convenience, this interface also encapsulates the fetching of 44 integer constants, i.e., enums. If no constant of this name was 45 present, either throws an (unspecified) run-time exception or 46 returns null. */ lookupIntConstant(String constantName, boolean throwException)47 public Integer lookupIntConstant(String constantName, boolean throwException); 48 49 /** Equivalent to lookupLongConstant(constantName, true) */ lookupLongConstant(String constantName)50 public Long lookupLongConstant(String constantName); 51 52 /* For convenience, this interface also encapsulates the fetching of 53 long constants (those requiring 64 bits on 64-bit platforms). If 54 no constant of this name was present, either throws an 55 (unspecified) run-time exception or returns null. */ lookupLongConstant(String constantName, boolean throwException)56 public Long lookupLongConstant(String constantName, boolean throwException); 57 58 /** Accessors for types representing the Java primitive types; used 59 for both proper type checking and for walking down Java arrays. */ getJBooleanType()60 public Type getJBooleanType(); getJByteType()61 public Type getJByteType(); getJCharType()62 public Type getJCharType(); getJDoubleType()63 public Type getJDoubleType(); getJFloatType()64 public Type getJFloatType(); getJIntType()65 public Type getJIntType(); getJLongType()66 public Type getJLongType(); getJShortType()67 public Type getJShortType(); 68 69 /** Returns the size of a C address in bytes. This is currently 70 needed in order to properly traverse an array of pointers. 71 Traversing an array of structs, for example, is possible by 72 looking up the type of the struct and multiplying the index by 73 its size when indexing off of a base Address. (FIXME: what about 74 alignment?) */ getAddressSize()75 public long getAddressSize(); 76 77 /** Returns the size of an oop in bytes. This is currently needed in 78 order to properly traverse an array of oops; it is distinguished 79 from the address size, above, because object pointers could 80 conceivably have a different representation than direct 81 pointers. Traversing an array of structs, for example, is 82 possible by looking up the type of the struct and multiplying 83 the index by its size when indexing off of a base Address. */ getOopSize()84 public long getOopSize(); 85 86 /** <P> This is an experimental interface emulating C++'s run-time 87 type information (RTTI) mechanism: determines whether the given 88 address is a pointer to the start of a C++ object of precisely 89 the given type -- it does not search superclasses of the type. 90 The convention is that this returns false for the null pointer. 91 It is needed to allow wrapper Java objects of the appropriate 92 type to be constructed for existing C++ objects of polymorphic 93 type. This method is only intended to work for C++ types 94 (implying that we should rename this package and the classes 95 contained within back to "ctypes"). Further, since the vptr 96 offset in an object is known at compile time but not necessarily 97 at runtime (unless debugging information is available), it is 98 reasonable for an implementation of this method to search nearby 99 memory for the (known) vtbl value for the given type. For this 100 reason, this method is not intended to support scans through 101 memory finding C++ objects, but is instead targeted towards 102 discovering the true type of a pointer assumed to be 103 intact. </P> 104 105 <P> The reason this method was placed in the type database is 106 that the latter is the first level at which it could be exposed, 107 and placing it here could avoid modifying the Type interface. It 108 is unclear what other, if any, vtbl access would be useful (or 109 implementable), so we are trying to avoid changing interfaces at 110 this point to support this kind of functionality. </P> 111 112 <P> This method necessarily does not support multiple 113 inheritance. </P> */ addressTypeIsEqualToType(Address addr, Type type)114 public boolean addressTypeIsEqualToType(Address addr, Type type); 115 116 /** Helper routine for guessing the most derived type of a 117 polymorphic C++ object. Iterates the type database calling 118 addressTypeIsEqualToType for all known types. Returns a matching 119 Type for the given address if one was found, or null if none was 120 found. */ guessTypeForAddress(Address addr)121 public Type guessTypeForAddress(Address addr); 122 123 /** Helper routine for guessing the most derived type of a 124 polymorphic C++ object. Requires a baseType that must be virtual 125 so that lookup can be performed without false positives */ findDynamicTypeForAddress(Address addr, Type baseType)126 public Type findDynamicTypeForAddress(Address addr, Type baseType); 127 128 /** Returns an Iterator over the Types in the database. */ getTypes()129 public Iterator getTypes(); 130 131 /** Returns an Iterator over the String names of the integer 132 constants in the database. */ getIntConstants()133 public Iterator getIntConstants(); 134 135 /** Returns an Iterator over the String names of the long constants 136 in the database. */ getLongConstants()137 public Iterator getLongConstants(); 138 } 139