public static int getSymbolicIntegerValue(MJIEnv env, int objRef, int v) { Object[] attrs = env.getArgAttributes(); IntegerExpression sym_arg = (IntegerExpression) attrs[0]; if (sym_arg != null) return env.newString(sym_arg.toString()); else return env.newString(Integer.toString(v)); }
@Override public Instruction execute(ThreadInfo th) { StackFrame sf = th.getModifiableTopFrame(); IntegerExpression sym_v1 = (IntegerExpression) sf.getOperandAttr(0); IntegerExpression sym_v2 = (IntegerExpression) sf.getOperandAttr(1); if (sym_v1 == null && sym_v2 == null) return super.execute(th); // we'll still do the concrete execution else { int v1 = sf.pop(); int v2 = sf.pop(); sf.push(0, false); // for symbolic expressions, the concrete value does not matter IntegerExpression result = null; if (sym_v1 != null) { if (sym_v2 != null) result = sym_v1._or(sym_v2); else // v2 is concrete result = sym_v1._or(v2); } else if (sym_v2 != null) result = sym_v2._or(v1); sf.setOperandAttr(result); // System.out.println("Execute IADD: "+result); return getNext(th); } }
@Override public Instruction execute(ThreadInfo th) { StackFrame sf = th.getModifiableTopFrame(); IntegerExpression sym_v1 = (IntegerExpression) sf.getOperandAttr(0); IntegerExpression sym_v2 = (IntegerExpression) sf.getOperandAttr(1); int v1, v2; if (sym_v1 == null && sym_v2 == null) return super.execute(th); // we'll still do the concrete execution // result is symbolic if (sym_v1 == null && sym_v2 != null) { v1 = sf.pop(); v2 = sf.pop(); if (v1 == 0) return th.createAndThrowException("java.lang.ArithmeticException", "div by 0"); sf.push(0, false); IntegerExpression result = sym_v2._div(v1); sf.setOperandAttr(result); return getNext(th); } // div by zero check affects path condition // sym_v1 is non-null and should be checked against zero ChoiceGenerator<?> cg; boolean condition; if (!th.isFirstStepInsn()) { // first time around cg = new PCChoiceGenerator(2); ((PCChoiceGenerator) cg).setOffset(this.position); ((PCChoiceGenerator) cg).setMethodName(this.getMethodInfo().getFullName()); th.getVM().setNextChoiceGenerator(cg); return this; } else { // this is what really returns results cg = th.getVM().getChoiceGenerator(); assert (cg instanceof PCChoiceGenerator) : "expected PCChoiceGenerator, got: " + cg; condition = (Integer) cg.getNextChoice() == 0 ? false : true; } v1 = sf.pop(); v2 = sf.pop(); sf.push(0, false); PathCondition pc; ChoiceGenerator<?> prev_cg = cg.getPreviousChoiceGeneratorOfType(PCChoiceGenerator.class); if (prev_cg == null) pc = new PathCondition(); else pc = ((PCChoiceGenerator) prev_cg).getCurrentPC(); assert pc != null; if (condition) { // check div by zero pc._addDet(Comparator.EQ, sym_v1, 0); if (pc.simplify()) { // satisfiable ((PCChoiceGenerator) cg).setCurrentPC(pc); return th.createAndThrowException("java.lang.ArithmeticException", "div by 0"); } else { th.getVM().getSystemState().setIgnored(true); return getNext(th); } } else { pc._addDet(Comparator.NE, sym_v1, 0); if (pc.simplify()) { // satisfiable ((PCChoiceGenerator) cg).setCurrentPC(pc); // set the result IntegerExpression result; if (sym_v2 != null) result = sym_v2._div(sym_v1); else result = sym_v1._div_reverse(v2); sf = th.getModifiableTopFrame(); sf.setOperandAttr(result); return getNext(th); } else { th.getVM().getSystemState().setIgnored(true); return getNext(th); } } }