1 cananian 1.1.4.1 // Linker.java, created Mon Dec 27 18:54:16 1999 by cananian
2 cananian 1.1.4.1 // Copyright (C) 1999 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.1.4.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1.4.1 package harpoon.ClassFile;
5 cananian 1.1.4.1
6 cananian 1.7 import net.cscott.jutil.ReferenceUnique;
7 cananian 1.1.4.1 import harpoon.Util.Util;
8 cananian 1.1.4.1
9 cananian 1.1.4.1 import java.util.HashMap;
10 cananian 1.1.4.1 import java.util.Map;
11 cananian 1.1.4.1 /**
12 cananian 1.1.4.1 * A <code>Linker</code> object manages the association of symbolic names
13 cananian 1.1.4.1 * to code/data/object descriptions.
14 cananian 1.1.4.1 *
15 cananian 1.1.4.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
16 cananian 1.7 * @version $Id: Linker.java,v 1.7 2004/02/08 01:58:03 cananian Exp $
17 cananian 1.1.4.1 */
18 cananian 1.1.4.1 public abstract class Linker implements ReferenceUnique {
19 cananian 1.1.4.1 protected Linker() { }
20 cananian 1.1.4.1 /** private linker cache, for efficiency. */
21 cananian 1.1.4.1 protected final Map descCache = new HashMap();
22 cananian 1.1.4.1 /**
23 cananian 1.1.4.1 * Synthetic classes will use this hook to register themselves in
24 cananian 1.1.4.1 * the namespace of this <code>Linker</code>. <b>The given class
25 cananian 1.1.4.1 * <code>hc</code> must be unique in the namespace of this linker.
26 cananian 1.1.4.1 * Not to be used if the <code>Linker</code> already contains a class
27 cananian 1.1.4.1 * with the same descriptor.</b> Use <code>Relinker</code> to do
28 cananian 1.1.4.1 * global replacement of classes.
29 cananian 1.1.4.1 * @see Relinker.relink
30 cananian 1.1.4.1 * @see uniqueName
31 cananian 1.1.4.1 */
32 cananian 1.1.4.1 void register(HClass hc) {
33 cananian 1.3.2.1 assert hc.getLinker()==this;
34 cananian 1.3.2.1 assert !descCache.containsKey(hc.getDescriptor());
35 cananian 1.1.4.1 descCache.put(hc.getDescriptor(), hc);
36 cananian 1.1.4.1 }
37 cananian 1.1.4.1
38 cananian 1.1.4.1 /**
39 cananian 1.1.4.1 * Sub-classes will provide implementation for the
40 cananian 1.1.4.1 * <code>forDescriptor0</code> method in order to implement
41 cananian 1.1.4.1 * a linking strategy. This method is only passed descriptors for
42 cananian 1.1.4.1 * class types; never array or primitive type descriptors.
43 cananian 1.1.4.1 * (Hence neither primitive types or array types can be
44 cananian 1.1.4.1 * re-linked, which might violate java language semantics.)
45 cananian 1.1.4.1 * @exception NoSuchClassException
46 cananian 1.1.4.1 * if the class could not be found.
47 cananian 1.1.4.1 */
48 cananian 1.1.4.1 protected abstract HClass forDescriptor0(String descriptor)
49 cananian 1.1.4.1 throws NoSuchClassException;
50 cananian 1.1.4.1
51 cananian 1.1.4.1 /**
52 cananian 1.1.4.1 * Returns the <code>HClass</code> object associated with the
53 cananian 1.1.4.1 * ComponentType descriptor given. Throws <code>NoSuchClassException</code>
54 cananian 1.1.4.1 * if the descriptor references a class that cannot be found. Throws
55 cananian 1.1.4.1 * <code>Error</code> if an invalid descriptor is given.
56 cananian 1.1.4.1 * @exception Error
57 cananian 1.1.4.1 * if an invalid descriptor is given.
58 cananian 1.1.4.1 * @exception NoSuchClassException
59 cananian 1.1.4.1 * if the class could not be found.
60 cananian 1.1.4.1 */
61 cananian 1.5 public HClass forDescriptor(String descriptor)
62 cananian 1.1.4.1 throws NoSuchClassException {
63 cananian 1.3.2.1 assert descriptor.indexOf('.')==-1; // should be desc, not name.
64 cananian 1.1.4.1 // Trim descriptor.
65 cananian 1.1.4.1 int i;
66 cananian 1.1.4.1 for (i=0; i<descriptor.length(); i++) {
67 cananian 1.1.4.1 char c = descriptor.charAt(i);
68 cananian 1.1.4.1 if (c=='(' || c==')') throw new Error("Bad Descriptor: "+descriptor);
69 cananian 1.1.4.1 if (c=='[') continue;
70 cananian 1.1.4.1 if (c=='L') i = descriptor.indexOf(';', i);
71 cananian 1.1.4.1 break;
72 cananian 1.1.4.1 }
73 cananian 1.1.4.1 descriptor = descriptor.substring(0, i+1);
74 cananian 1.1.4.1 // Check the cache and ensure uniqueness.
75 cananian 1.1.4.1 HClass cls = (HClass) descCache.get(descriptor);
76 cananian 1.1.4.1 if (cls==null) { // not in the cache.
77 cananian 1.1.4.1 cls = _forDescriptor_(descriptor); // do actual descriptor resolution.
78 cananian 1.3.2.1 assert !descCache.containsKey(descriptor);
79 cananian 1.3.2.1 assert descriptor.equals(cls.getDescriptor()) : "The given class name does not match the class' idea of its name\n"
80 witchel 1.1.4.5 + "Try giving the full name to -c"
81 witchel 1.1.4.5 + "\nDescriptor " + descriptor + "\ncls " + cls
82 cananian 1.3.2.1 + "\ncls descriptor " + cls.getDescriptor();
83 cananian 1.1.4.1 descCache.put(descriptor, cls);
84 cananian 1.1.4.1 }
85 cananian 1.1.4.1 return cls;
86 cananian 1.1.4.1 }
87 cananian 1.1.4.1 // helper function for the above; split apart to make the caching
88 cananian 1.1.4.1 // behavior of the above clearer.
89 cananian 1.1.4.1 private HClass _forDescriptor_(String descriptor)
90 cananian 1.1.4.1 throws NoSuchClassException {
91 cananian 1.1.4.1 switch(descriptor.charAt(0)) {
92 cananian 1.1.4.1 case '[': // arrays.
93 cananian 1.1.4.1 {
94 cananian 1.1.4.1 // count dimensions
95 cananian 1.1.4.1 int d;
96 cananian 1.1.4.1 for (d=0; d<descriptor.length(); d++)
97 cananian 1.1.4.1 if (descriptor.charAt(d)!='[')
98 cananian 1.1.4.1 break;
99 cananian 1.1.4.1 // recurse to fetch base type.
100 cananian 1.1.4.1 HClass basetype = forDescriptor(descriptor.substring(d));
101 cananian 1.1.4.1 // make it.
102 cananian 1.1.4.4 HClass arraytype = makeArray(basetype, d);
103 cananian 1.3.2.1 assert arraytype.getDescriptor().equals(descriptor);
104 cananian 1.1.4.4 return arraytype;
105 cananian 1.1.4.1 }
106 cananian 1.1.4.1 case 'L': // object type.
107 cananian 1.1.4.1 return forDescriptor0(descriptor);
108 cananian 1.1.4.1 case 'B': // primitive types.
109 cananian 1.1.4.1 return HClass.Byte;
110 cananian 1.1.4.1 case 'C':
111 cananian 1.1.4.1 return HClass.Char;
112 cananian 1.1.4.1 case 'D':
113 cananian 1.1.4.1 return HClass.Double;
114 cananian 1.1.4.1 case 'F':
115 cananian 1.1.4.1 return HClass.Float;
116 cananian 1.1.4.1 case 'I':
117 cananian 1.1.4.1 return HClass.Int;
118 cananian 1.1.4.1 case 'J':
119 cananian 1.1.4.1 return HClass.Long;
120 cananian 1.1.4.1 case 'S':
121 cananian 1.1.4.1 return HClass.Short;
122 cananian 1.1.4.1 case 'Z':
123 cananian 1.1.4.1 return HClass.Boolean;
124 cananian 1.1.4.1 case 'V':
125 cananian 1.1.4.1 return HClass.Void;
126 cananian 1.1.4.1 default:
127 cananian 1.1.4.1 break;
128 cananian 1.1.4.1 }
129 cananian 1.1.4.1 throw new Error("Bad Descriptor: "+descriptor);
130 cananian 1.1.4.4 }
131 cananian 1.1.4.4 /** Allow Linker subclass to substitute a different (mutable?)
132 cananian 1.1.4.4 * array class type. */
133 cananian 1.1.4.4 protected HClass makeArray(HClass baseType, int dims) {
134 cananian 1.1.4.4 return new HClassArray(this, baseType, dims);
135 cananian 1.1.4.1 }
136 cananian 1.1.4.1
137 cananian 1.1.4.1 /**
138 cananian 1.1.4.1 * Returns the <code>HClass</code> object associated with the class with
139 cananian 1.1.4.1 * the given string name. Given the fully-qualified name for a class or
140 cananian 1.1.4.1 * interface, this method attempts to locate and load the class. If it
141 cananian 1.1.4.1 * succeeds, returns the <code>HClass</code> object representing the class.
142 cananian 1.1.4.1 * If it fails, the method throws a <code>NoSuchClassException</code>.
143 cananian 1.1.4.1 * @param className the fully qualified name of the desired class.
144 cananian 1.1.4.1 * @return the <code>HClass</code> descriptor for the class with the
145 cananian 1.1.4.1 * specified name.
146 cananian 1.1.4.1 * @exception NoSuchClassException
147 cananian 1.1.4.1 * if the class could not be found.
148 cananian 1.1.4.1 */
149 cananian 1.1.4.1 public final HClass forName(String className) throws NoSuchClassException {
150 cananian 1.1.4.1 if (className.charAt(0)=='[') {
151 cananian 1.3.2.1 assert className.indexOf('.')==-1 : "Class name " + className; // should be desc, not name.
152 cananian 1.1.4.1 return forDescriptor(className);
153 cananian 1.1.4.1 } else {
154 cananian 1.6 assert className.indexOf('/')==-1:className; // should be name, not desc.
155 cananian 1.1.4.1 return forDescriptor("L"+className.replace('.','/')+";");
156 cananian 1.1.4.1 }
157 cananian 1.1.4.1 }
158 cananian 1.1.4.1
159 cananian 1.1.4.1 /**
160 cananian 1.1.4.1 * Returns the <code>HClass</code> object associated with the given java
161 cananian 1.1.4.1 * <code>Class</code> object. If (for some reason) the class file
162 cananian 1.1.4.1 * cannot be found, the method throws a <code>NoSuchClassException</code>.
163 cananian 1.1.4.1 * @return the <code>HClass</code> descriptor for this <code>Class</code>.
164 cananian 1.1.4.1 * @exception NoSuchClassException
165 cananian 1.1.4.1 * if the classfile could not be found.
166 cananian 1.1.4.1 * @deprecated Don't use java.lang.Class objects if you can help it.
167 cananian 1.1.4.1 */
168 cananian 1.1.4.1 public final HClass forClass(Class cls) throws NoSuchClassException {
169 cananian 1.1.4.1 // if cls is an array...
170 cananian 1.1.4.1 if (cls.isArray())
171 cananian 1.1.4.1 return forDescriptor("[" +
172 cananian 1.1.4.1 forClass(cls.getComponentType()).getDescriptor());
173 cananian 1.1.4.1 // or else if it's a primitive type...
174 cananian 1.1.4.1 if (cls.isPrimitive()) {
175 cananian 1.1.4.1 if (cls == java.lang.Boolean.TYPE) return forDescriptor("Z");
176 cananian 1.1.4.1 if (cls == java.lang.Character.TYPE) return forDescriptor("C");
177 cananian 1.1.4.1 if (cls == java.lang.Byte.TYPE) return forDescriptor("B");
178 cananian 1.1.4.1 if (cls == java.lang.Short.TYPE) return forDescriptor("S");
179 cananian 1.1.4.1 if (cls == java.lang.Integer.TYPE) return forDescriptor("I");
180 cananian 1.1.4.1 if (cls == java.lang.Long.TYPE) return forDescriptor("J");
181 cananian 1.1.4.1 if (cls == java.lang.Float.TYPE) return forDescriptor("F");
182 cananian 1.1.4.1 if (cls == java.lang.Double.TYPE) return forDescriptor("D");
183 cananian 1.1.4.1 if (cls == java.lang.Void.TYPE) return forDescriptor("V");
184 cananian 1.1.4.1 throw new NoSuchClassException("Unknown class primitive: "+cls);
185 cananian 1.1.4.1 }
186 cananian 1.1.4.1 // otherwise...
187 cananian 1.1.4.1 return forName(cls.getName());
188 cananian 1.1.4.1 }
189 cananian 1.1.4.1
190 cananian 1.1.4.1 /** Creates a new mutable class with the given name which is
191 cananian 1.1.4.1 * based on the given template class. <b>The <code>name</code>
192 cananian 1.1.4.1 * must be unique.</b>
193 cananian 1.1.4.1 * @exception DuplicateClassException if the given name is not unique;
194 cananian 1.1.4.1 * that is, it corresponds to a loadable class.
195 cananian 1.1.4.1 */
196 cananian 1.1.4.1 public HClass createMutableClass(String name, HClass template)
197 cananian 1.1.4.1 throws DuplicateClassException {
198 cananian 1.3.2.1 assert template.getLinker()==this;
199 cananian 1.1.4.1 try {
200 cananian 1.1.4.1 forName(name);
201 cananian 1.1.4.1 throw new DuplicateClassException(name);
202 cananian 1.1.4.1 } catch (NoSuchClassException e) { /* named class not found, continue */ }
203 cananian 1.1.4.1 // okay, create a mutable class...
204 cananian 1.1.4.1 HClass hc = new HClassSyn(this, name, template);
205 cananian 1.1.4.1 hc.hasBeenModified = true;
206 cananian 1.1.4.1 register(hc);
207 cananian 1.1.4.1 return hc;
208 cananian 1.1.4.1 }
209 cananian 1.1.4.1 }
210 cananian 1.1.4.1
211 cananian 1.1.4.1 // set emacs indentation style.
212 cananian 1.1.4.1 // Local Variables:
213 cananian 1.1.4.1 // c-basic-offset:2
214 cananian 1.2 // End: