//
// Copyright (C) 2006 United States Government as represented by the
// Administrator of the National Aeronautics and Space Administration
// (NASA). All Rights Reserved.
//
// This software is distributed under the NASA Open Source Agreement
// (NOSA), version 1.3. The NOSA has been approved by the Open Source
// Initiative. See the file NOSA-1.3-JPF at the top of the distribution
// directory tree for the complete NOSA document.
//
// THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY
// KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT
// LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO
// SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
// A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT
// THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT
// DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE.
//
package gov.nasa.jpf.test.mc.basic;
import org.junit.Test;
import cmu.conditional.One;
import de.fosd.typechef.featureexpr.FeatureExpr;
import de.fosd.typechef.featureexpr.FeatureExprFactory;
import gov.nasa.jpf.ListenerAdapter;
import gov.nasa.jpf.jvm.bytecode.GETFIELD;
import gov.nasa.jpf.jvm.bytecode.IRETURN;
import gov.nasa.jpf.jvm.bytecode.InvokeInstruction;
import gov.nasa.jpf.util.test.TestJPF;
import gov.nasa.jpf.vm.ClassInfo;
import gov.nasa.jpf.vm.Instruction;
import gov.nasa.jpf.vm.MethodInfo;
import gov.nasa.jpf.vm.StackFrame;
import gov.nasa.jpf.vm.ThreadInfo;
import gov.nasa.jpf.vm.VM;
import gov.nasa.jpf.vm.choice.IntChoiceFromList;
public class SkipInstructionTest extends TestJPF {
//--- replacing field access
int answer = 0;
public static class GetFieldListener extends ListenerAdapter {
@Override
public void executeInstruction(FeatureExpr ctx, VM vm, ThreadInfo ti, Instruction insnToExecute) {
Instruction pc = ti.getPC().getValue();
if (pc instanceof GETFIELD) {
GETFIELD gf = (GETFIELD) pc;
if (gf.getVariableId().equals(SkipInstructionTest.class.getName() + ".answer")) {
System.out.println("now intercepting: " + pc);
// simulate the operand stack behavior of the skipped insn
StackFrame frame = ti.getModifiableTopFrame();
frame.pop(FeatureExprFactory.True());
frame.push(FeatureExprFactory.True(), One.valueOf(42));
ti.skipInstruction(pc.getNext());
}
}
}
}
@Test
public void testGETFIELD () {
if (verifyNoPropertyViolation("+listener=gov.nasa.jpf.test.mc.basic.SkipInstructionTest$GetFieldListener")){
int i = answer; // to be intercepted by listener
System.out.println(i);
assert (i == 42) : "get_field not intercepted: " + i;
}
}
//--- replacing method execution
// this is not using skipInstruction but is setting the next one to enter, which
// means it can skip over a whole bunch of things. The use that comes to mind is to
// skip over method bodies, but still preserve the invoke processing so that we
// preserve the locking/sync (which we otherwise would have to do explicitly from
// a pre-exec listener
// the intercepted method
int foo (int a, int b) {
int result = a + b;
if (result > 10) {
return 10;
} else {
return result;
}
}
// the listener that does the interception
public static class InvokeListener extends ListenerAdapter {
MethodInfo interceptedMethod;
@Override
public void classLoaded (VM vm, ClassInfo ci) {
if (ci.getName().equals("gov.nasa.jpf.test.mc.basic.SkipInstructionTest")) {
interceptedMethod = ci.getMethod("foo(II)I", false);
assert interceptedMethod != null : "foo(II)I not found";
System.out.println("method to intercept: " + interceptedMethod);
}
}
@Override
public void instructionExecuted (VM vm, ThreadInfo ti, Instruction nextInsn, Instruction executedInsn) {
MethodInfo mi = ti.getTopFrameMethodInfo();
if (mi == interceptedMethod) {
System.out.println("in " + mi);
if (!ti.isFirstStepInsn()) {
System.out.println("in top half: " + executedInsn);
if (executedInsn instanceof InvokeInstruction) { // we just entered the interceptedMethod
IntChoiceFromList cg = new IntChoiceFromList("Test", 42, 43);
if (vm.setNextChoiceGenerator(cg)) {
return; // we are done here, next insn in this method will skip to return
}
}
} else {
// note - this is the first insn WITHIN the interceptedMethod
System.out.println("in bottom half: " + executedInsn);
IntChoiceFromList cg = vm.getCurrentChoiceGenerator("Test", IntChoiceFromList.class);
if (cg != null) {
int choice = cg.getNextChoice();
Instruction lastInsn = mi.getLastInsn();
assert lastInsn instanceof IRETURN : "last instruction not an IRETURN ";
StackFrame frame = ti.getModifiableTopFrame(); // we are modifying it
System.out.println("listener is skipping method body of " + mi + " returning " + choice);
frame.push(FeatureExprFactory.True(), One.valueOf(choice));
ti.setNextPC(lastInsn);
} else {
System.out.println("unexpected CG: " + cg);
}
}
}
}
}
@Test
public void testSkipMethodBody() {
if (verifyNoPropertyViolation("+listener=gov.nasa.jpf.test.mc.basic.SkipInstructionTest$InvokeListener")){
int ret = foo( 3, 4);
System.out.println(ret);
//assertTrue( ret == 42);
}
}
}