1 cananian 1.1.2.1 // COMPONENTOF.java, created Wed Sep 9 13:05:33 1998 by cananian
2 cananian 1.1.2.1 // Copyright (C) 1998 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.1.2.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1.2.1 package harpoon.IR.Quads;
5 cananian 1.1.2.1
6 cananian 1.1.2.7 import harpoon.ClassFile.HCodeElement;
7 cananian 1.1.2.1 import harpoon.Temp.Temp;
8 cananian 1.1.2.1 import harpoon.Temp.TempMap;
9 cananian 1.1.2.2 import harpoon.Util.Util;
10 cananian 1.1.2.2
11 cananian 1.1.2.1 /**
12 cananian 1.1.2.1 * <code>COMPONENTOF</code> objects implement the test needed to determine
13 cananian 1.1.2.1 * if an <code>ASET</code> needs to throw an exception. Specifically,
14 cananian 1.1.2.1 * <code>COMPONENTOF</code> evaluates to boolean <code>true</code> if
15 cananian 1.1.2.10 * a certain temporary is an instance of the component
16 cananian 1.1.2.10 * type of a certain array, or boolean <code>false</code> otherwise.
17 cananian 1.1.2.10 * The given array should <strong>never</strong> have components of primitive
18 cananian 1.1.2.10 * type, as <code>COMPONENTOF</code> would always return <code>true</code> in
19 cananian 1.1.2.10 * this case, given a type-safe program.<p>
20 cananian 1.1.2.10 *
21 cananian 1.1.2.10 * <strong>In quad-with-try form ONLY:</strong>
22 cananian 1.1.2.10 * The component object to test (<code>componentref</code>) may have
23 cananian 1.1.2.10 * the value null, in which case <code>COMPONENTOF</code> returns
24 cananian 1.1.2.10 * <code>true</code> (it is always safe to store <code>null</code>
25 cananian 1.1.2.10 * in an object array).
26 cananian 1.1.2.10 * <strong>In all other forms the component object must be provably
27 cananian 1.1.2.10 * non-null.</strong> An explicit null-check may be needed prior to the
28 cananian 1.1.2.10 * <code>COMPONENTOF</code> if the component object cannot be
29 cananian 1.1.2.10 * proven non-null.
30 cananian 1.1.2.1 *
31 cananian 1.1.2.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
32 cananian 1.5 * @version $Id: COMPONENTOF.java,v 1.5 2002/04/11 04:00:34 cananian Exp $
33 cananian 1.1.2.1 * @see ASET
34 cananian 1.1.2.1 * @see "The Java Virtual Machine Specification"
35 cananian 1.1.2.1 */
36 cananian 1.1.2.1 public class COMPONENTOF extends Quad {
37 cananian 1.1.2.2 /** The <code>Temp</code> in which to store the result of the test. */
38 cananian 1.1.2.2 protected Temp dst;
39 cananian 1.1.2.1 /** The array object to test. */
40 cananian 1.1.2.2 protected Temp arrayref;
41 cananian 1.1.2.9 /** The component object to test. */
42 cananian 1.1.2.2 protected Temp objectref;
43 cananian 1.1.2.1
44 cananian 1.1.2.2 /** Creates a <code>COMPONENTOF</code> representing a typecheck test.
45 cananian 1.1.2.2 * @param dst
46 cananian 1.1.2.2 * the <code>Temp</code> in which to store the result of the test.
47 cananian 1.1.2.2 * The <code>Temp</code> specified by <code>dst</code> gets a
48 cananian 1.1.2.2 * boolean <code>true</code> value if <code>objectref</code>
49 cananian 1.1.2.10 * contains a reference to an instance
50 cananian 1.1.2.2 * of the component type of the array in <code>arrayref</code>
51 cananian 1.1.2.2 * or any subtype; or a boolean <code>false</code> value otherwise.
52 cananian 1.1.2.10 * In quad-with-try form <strong>only</strong>, the result is also
53 cananian 1.1.2.10 * <code>true</code> if <code>objectref</code> is
54 cananian 1.1.2.10 * <code>null</code>; in all other forms this possibility
55 cananian 1.1.2.10 * is a semantic error.
56 cananian 1.1.2.2 * @param arrayref
57 cananian 1.1.2.10 * the array object to test. <strong>Should never be an
58 cananian 1.1.2.10 * array of primitive component type.</strong>
59 cananian 1.1.2.2 * The <code>Temp</code> specified by <code>arrayref</code>
60 cananian 1.1.2.2 * <strong>should never</strong> contain the value
61 cananian 1.1.2.2 * <code>null</code> at run-time.
62 cananian 1.1.2.2 * @param objectref
63 cananian 1.1.2.2 * the component object to test.
64 cananian 1.1.2.2 * The <code>Temp</code> specified by <code>objectref</code>
65 cananian 1.1.2.2 * <strong>may</strong> contain the value <code>null</code>
66 cananian 1.1.2.10 * at run-time <strong>if and only if</strong> we are in
67 cananian 1.1.2.10 * quad-with-try form.
68 cananian 1.1.2.2 */
69 cananian 1.1.2.4 public COMPONENTOF(QuadFactory qf, HCodeElement source,
70 cananian 1.1.2.1 Temp dst, Temp arrayref, Temp objectref) {
71 cananian 1.1.2.4 super(qf, source);
72 cananian 1.1.2.1 this.dst = dst;
73 cananian 1.1.2.1 this.arrayref = arrayref;
74 cananian 1.1.2.1 this.objectref = objectref;
75 cananian 1.3.2.1 assert dst!=null && arrayref!=null && objectref!=null;
76 cananian 1.1.2.1 }
77 cananian 1.1.2.2 // ACCESSOR METHODS:
78 cananian 1.1.2.2 /** Returns the <code>Temp</code> in which to store the result of the
79 cananian 1.1.2.2 * type check test. */
80 cananian 1.1.2.2 public Temp dst() { return dst; }
81 cananian 1.1.2.2 /** Returns the array reference to test. */
82 cananian 1.1.2.2 public Temp arrayref() { return arrayref; }
83 cananian 1.1.2.2 /** Returns the component object reference to test. */
84 cananian 1.1.2.2 public Temp objectref() { return objectref; }
85 cananian 1.1.2.2
86 cananian 1.1.2.1 /** Returns the <code>Temp</code>s used by this quad. */
87 cananian 1.1.2.1 public Temp[] use() { return new Temp[] { arrayref, objectref }; }
88 cananian 1.1.2.1 /** Returns the <code>Temp</code>s defined by this quad. */
89 cananian 1.1.2.1 public Temp[] def() { return new Temp[] { dst }; }
90 cananian 1.1.2.1
91 cananian 1.1.2.3 public int kind() { return QuadKind.COMPONENTOF; }
92 cananian 1.1.2.3
93 cananian 1.1.2.5 public Quad rename(QuadFactory qqf, TempMap defMap, TempMap useMap) {
94 cananian 1.1.2.5 return new COMPONENTOF(qqf, this, map(defMap,dst),
95 cananian 1.1.2.5 map(useMap,arrayref), map(useMap,objectref));
96 cananian 1.1.2.3 }
97 cananian 1.1.2.5 /** Rename all used variables in this Quad according to a mapping.
98 cananian 1.1.2.5 * @deprecated does not preserve immutability. */
99 cananian 1.1.2.3 void renameUses(TempMap tm) {
100 cananian 1.1.2.1 arrayref = tm.tempMap(arrayref);
101 cananian 1.1.2.1 objectref = tm.tempMap(objectref);
102 cananian 1.1.2.1 }
103 cananian 1.1.2.5 /** Rename all defined variables in this Quad according to a mapping.
104 cananian 1.1.2.5 * @deprecated does not preserve immutability. */
105 cananian 1.1.2.3 void renameDefs(TempMap tm) {
106 cananian 1.1.2.1 dst = tm.tempMap(dst);
107 cananian 1.1.2.1 }
108 cananian 1.1.2.1
109 cananian 1.1.2.8 public void accept(QuadVisitor v) { v.visit(this); }
110 cananian 1.5 public <T> T accept(QuadValueVisitor<T> v) { return v.visit(this); }
111 cananian 1.1.2.1
112 cananian 1.1.2.1 /** Returns a human-readable representation of this Quad. */
113 cananian 1.1.2.1 public String toString() {
114 cananian 1.1.2.1 return dst.toString() + " = " +
115 cananian 1.1.2.1 objectref.toString() + " COMPONENTOF " + arrayref.toString();
116 cananian 1.1.2.1 }
117 cananian 1.2 }