001: /***
002: * ASM Guide
003: * Copyright (c) 2007 Eric Bruneton
004: * All rights reserved.
005: *
006: * Redistribution and use in source and binary forms, with or without
007: * modification, are permitted provided that the following conditions
008: * are met:
009: * 1. Redistributions of source code must retain the above copyright
010: * notice, this list of conditions and the following disclaimer.
011: * 2. Redistributions in binary form must reproduce the above copyright
012: * notice, this list of conditions and the following disclaimer in the
013: * documentation and/or other materials provided with the distribution.
014: * 3. Neither the name of the copyright holders nor the names of its
015: * contributors may be used to endorse or promote products derived from
016: * this software without specific prior written permission.
017: *
018: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
019: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
020: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
021: * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
022: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
023: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
024: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
025: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
026: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
027: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
028: * THE POSSIBILITY OF SUCH DAMAGE.
029: */package ch6.sec1;
030:
031: import static org.objectweb.asm.Opcodes.ACC_INTERFACE;
032: import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
033: import static org.objectweb.asm.Opcodes.ACC_STATIC;
034: import static org.objectweb.asm.Opcodes.ATHROW;
035: import static org.objectweb.asm.Opcodes.GETSTATIC;
036: import static org.objectweb.asm.Opcodes.INVOKESTATIC;
037: import static org.objectweb.asm.Opcodes.IRETURN;
038: import static org.objectweb.asm.Opcodes.LADD;
039: import static org.objectweb.asm.Opcodes.LSUB;
040: import static org.objectweb.asm.Opcodes.PUTSTATIC;
041: import static org.objectweb.asm.Opcodes.RETURN;
042:
043: import java.util.Iterator;
044: import java.util.List;
045:
046: import org.objectweb.asm.tree.AbstractInsnNode;
047: import org.objectweb.asm.tree.ClassNode;
048: import org.objectweb.asm.tree.FieldInsnNode;
049: import org.objectweb.asm.tree.FieldNode;
050: import org.objectweb.asm.tree.InsnList;
051: import org.objectweb.asm.tree.InsnNode;
052: import org.objectweb.asm.tree.MethodInsnNode;
053: import org.objectweb.asm.tree.MethodNode;
054:
055: import ch5.sec1.ClassTransformer;
056:
057: /**
058: * ASM Guide example class.
059: *
060: * @author Eric Bruneton
061: */
062: public class AddTimerTransformer extends ClassTransformer {
063:
064: public AddTimerTransformer(ClassTransformer ct) {
065: super (ct);
066: }
067:
068: public void transform(ClassNode cn) {
069: if ((cn.access & ACC_INTERFACE) == 0) {
070: for (MethodNode mn : (List<MethodNode>) cn.methods) {
071: if ("<init>".equals(mn.name)
072: || "<clinit>".equals(mn.name)) {
073: continue;
074: }
075: InsnList insns = mn.instructions;
076: if (insns.size() == 0) {
077: continue;
078: }
079: Iterator j = insns.iterator();
080: while (j.hasNext()) {
081: AbstractInsnNode in = (AbstractInsnNode) j.next();
082: int op = in.getOpcode();
083: if ((op >= IRETURN && op <= RETURN) || op == ATHROW) {
084: InsnList il = new InsnList();
085: il.add(new FieldInsnNode(GETSTATIC, cn.name,
086: "timer", "J"));
087: il.add(new MethodInsnNode(INVOKESTATIC,
088: "java/lang/System",
089: "currentTimeMillis", "()J"));
090: il.add(new InsnNode(LADD));
091: il.add(new FieldInsnNode(PUTSTATIC, cn.name,
092: "timer", "J"));
093: if (in.getPrevious() == null) {
094: continue;
095: }
096: insns.insert(in.getPrevious(), il);
097: }
098: }
099: InsnList il = new InsnList();
100: il.add(new FieldInsnNode(GETSTATIC, cn.name, "timer",
101: "J"));
102: il
103: .add(new MethodInsnNode(INVOKESTATIC,
104: "java/lang/System",
105: "currentTimeMillis", "()J"));
106: il.add(new InsnNode(LSUB));
107: il.add(new FieldInsnNode(PUTSTATIC, cn.name, "timer",
108: "J"));
109: insns.insert(il);
110:
111: mn.maxStack += 4;
112: }
113: int acc = ACC_PUBLIC + ACC_STATIC;
114: cn.fields.add(new FieldNode(acc, "timer", "J", null, null));
115: }
116: super.transform(cn);
117: }
118: }
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