findpuzzlers.java

A static analysis tool to find bugs in Java programs

						.addClassAndMethod(this)
						.addInt(valueOfConstantArgumentToShift).describe(IntAnnotation.INT_SHIFT)
						.addSourceLine(this)
						);
				}
				if (leftHandSide != null 
						&& leftHandSide instanceof Integer
						&& ((Integer) leftHandSide)
						> 0) {
					// boring; lie so other detectors won't get concerned
					constantArgumentToShift = true;
					valueOfConstantArgumentToShift = 8;
				}
			}
		}



		if (seen == INVOKEVIRTUAL && stack.getStackDepth() > 0
				&& getClassConstantOperand().equals("java/util/Date")
				&& getNameConstantOperand().equals("setMonth")
				&& getSigConstantOperand().equals("(I)V")) {
			OpcodeStack.Item item = stack.getStackItem(0);
			Object o = item.getConstant();
			if (o != null && o instanceof Integer) {
				int v = (Integer) o;
				if (v < 0 || v > 11)
					bugReporter.reportBug(new BugInstance(this, "DMI_BAD_MONTH", NORMAL_PRIORITY)
					.addClassAndMethod(this)
					.addInt(v).describe(IntAnnotation.INT_VALUE)
					.addCalledMethod(this)
					.addSourceLine(this)
					);
			}
		}

		if (seen == INVOKEVIRTUAL && stack.getStackDepth() > 1
				&& getClassConstantOperand().equals("java/util/Calendar")
				&& getNameConstantOperand().equals("set")

				||
				seen == INVOKESPECIAL && stack.getStackDepth() > 1
				&& getClassConstantOperand().equals("java/util/GregorianCalendar")
				&& getNameConstantOperand().equals("<init>")

		) {
			String sig = getSigConstantOperand();
			if (sig.startsWith("(III")) {
				int pos = sig.length() - 5;
				OpcodeStack.Item item = stack.getStackItem(pos);
				Object o = item.getConstant();
				if (o != null && o instanceof Integer) {
					int v = (Integer) o;
					if (v < 0 || v > 11)
						bugReporter.reportBug(new BugInstance(this, "DMI_BAD_MONTH", NORMAL_PRIORITY)
						.addClassAndMethod(this)
						.addInt(v).describe(IntAnnotation.INT_VALUE)
						.addCalledMethod(this)
						.addSourceLine(this)
						);
				}
			}
		}



		if (isRegisterStore() && (seen == ISTORE 
				|| seen == ISTORE_0
				|| seen == ISTORE_1
				|| seen == ISTORE_2
				|| seen == ISTORE_3)
				&& getRegisterOperand() == prevOpcodeIncrementedRegister) {
			bugReporter.reportBug(new BugInstance(this, "DLS_OVERWRITTEN_INCREMENT", HIGH_PRIORITY)
			.addClassAndMethod(this)
			.addSourceLine(this));

		}
		if (seen == IINC) {
			prevOpcodeIncrementedRegister = getRegisterOperand();	
		}
		else
			prevOpcodeIncrementedRegister = -1;


		// Java Puzzlers, Chapter 2, puzzle 1
		// Look for ICONST_2 IREM ICONST_1  IF_ICMPNE L1

		switch (badlyComputingOddState) {
		case 0:
			if (seen == ICONST_2) badlyComputingOddState++;
			break;
		case 1:
			if (seen == IREM) {
				OpcodeStack.Item item = stack.getStackItem(1);
				if (item.getSpecialKind() != OpcodeStack.Item.MATH_ABS)
					badlyComputingOddState++;
				else  badlyComputingOddState = 0;
			}
			else badlyComputingOddState = 0;
			break;
		case 2:
			if (seen == ICONST_1) badlyComputingOddState++;
			else badlyComputingOddState = 0;
			break;
		case 3:
			if (seen == IF_ICMPEQ || seen == IF_ICMPNE)  {
				bugReporter.reportBug(new BugInstance(this, "IM_BAD_CHECK_FOR_ODD", NORMAL_PRIORITY)
				.addClassAndMethod(this)
				.addSourceLine(this));
			}
			badlyComputingOddState = 0;
			break;
		}

		// Java Puzzlers, chapter 3, puzzle 12
		if (seen == INVOKEVIRTUAL && stack.getStackDepth() > 0 
				&& (getNameConstantOperand().equals("toString")
						&& getSigConstantOperand().equals("()Ljava/lang/String;")
						|| getNameConstantOperand().equals("append")
						&& getSigConstantOperand().equals("(Ljava/lang/Object;)Ljava/lang/StringBuilder;") && getClassConstantOperand().equals("java/lang/StringBuilder")
						|| getNameConstantOperand().equals("append")
						&& getSigConstantOperand().equals("(Ljava/lang/Object;)Ljava/lang/StringBuffer;") && getClassConstantOperand().equals("java/lang/StringBuffer")
				)
		) {
			String classConstants = getClassConstantOperand();
			OpcodeStack.Item item = stack.getStackItem(0);
			String signature = item.getSignature();
			if (signature != null && signature.startsWith("[")) 
				bugReporter.reportBug(new BugInstance(this, "DMI_INVOKING_TOSTRING_ON_ARRAY", NORMAL_PRIORITY)
				.addClassAndMethod(this)
				.addSourceLine(this));
		}

		if (isTigerOrHigher) {
			if (previousMethodInvocation != null && prevOpCode == INVOKESPECIAL && seen == INVOKEVIRTUAL) {
				String classNameForPreviousMethod = previousMethodInvocation.getClassName();
				String classNameForThisMethod = getClassConstantOperand();
				if (classNameForPreviousMethod.startsWith("java.lang.") 
						&& classNameForPreviousMethod.equals(classNameForThisMethod.replace('/','.'))
						&& getNameConstantOperand().endsWith("Value")
						&& getSigConstantOperand().length() == 3) {
					if (getSigConstantOperand().charAt(2) == previousMethodInvocation.getSignature().charAt(1))
						bugReporter.reportBug(new BugInstance(this, "BX_BOXING_IMMEDIATELY_UNBOXED", NORMAL_PRIORITY)
						.addClassAndMethod(this)
						.addSourceLine(this));
					else 
						bugReporter.reportBug(new BugInstance(this, "BX_BOXING_IMMEDIATELY_UNBOXED_TO_PERFORM_COERCION", NORMAL_PRIORITY)
						.addClassAndMethod(this)
						.addSourceLine(this));
					ternaryConversionState = 1;
				} else ternaryConversionState = 0;

			} else if (seen == INVOKEVIRTUAL) {
				if (getClassConstantOperand().startsWith("java/lang") && getNameConstantOperand().endsWith("Value") && getSigConstantOperand().length() == 3)
					ternaryConversionState = 1;
				else ternaryConversionState = 0;
			}else if (ternaryConversionState == 1) {
				if (I2L <= seen && seen <= I2S) 
					ternaryConversionState = 2;
				else ternaryConversionState = 0;
			}
			else if (ternaryConversionState == 2) {
				ternaryConversionState = 0;
				if (seen == GOTO) 
					bugReporter.reportBug(new BugInstance(this, "BX_UNBOXED_AND_COERCED_FOR_TERNARY_OPERATOR", NORMAL_PRIORITY)
					.addClassAndMethod(this)
					.addSourceLine(this));
			}
		}

		if (seen == INVOKESTATIC)
			if ((getNameConstantOperand().startsWith("assert") || getNameConstantOperand().startsWith("fail")) && getMethodName().equals("run")
					&& implementsRunnable(getThisClass())) {
				try {
					 int size1 = Util.getSizeOfSurroundingTryBlock(getConstantPool(), getMethod().getCode(),
                    								"java/lang/Throwable", getPC());
					int size2 = Util.getSizeOfSurroundingTryBlock(getConstantPool(), getMethod().getCode(),
                    										"java/lang/Error", getPC());
					int size3 = Util.getSizeOfSurroundingTryBlock(getConstantPool(), getMethod().getCode(),
                    												"java/lang/AssertionFailureError", getPC());
					int size = Math.min(Math.min( size1, size2), size3);
					 if (size == Integer.MAX_VALUE) {
					JavaClass targetClass = AnalysisContext.currentAnalysisContext().lookupClass(getClassConstantOperand().replace('/', '.'));
					if (targetClass.getSuperclassName().startsWith("junit")) {
						bugReporter.reportBug(new BugInstance(this, "IJU_ASSERT_METHOD_INVOKED_FROM_RUN_METHOD", NORMAL_PRIORITY)
						.addClassAndMethod(this)
						.addSourceLine(this));

					}
					 }
				} catch (ClassNotFoundException e) {
					AnalysisContext.reportMissingClass(e);
				}

			}
		stack.sawOpcode(this,seen);
		if (seen == INVOKESPECIAL && getClassConstantOperand().startsWith("java/lang/")  && getNameConstantOperand().equals("<init>")
				&& getSigConstantOperand().length() == 4
		) 

			previousMethodInvocation = XFactory.createReferencedXMethod(this);
		else if (seen == INVOKESTATIC && getClassConstantOperand().startsWith("java/lang/")  
				&& getNameConstantOperand().equals("valueOf")
				&& getSigConstantOperand().length() == 4) 
			previousMethodInvocation = XFactory.createReferencedXMethod(this);
		else previousMethodInvocation = null;
		prevOpCode = seen;
	}
	boolean implementsRunnable(JavaClass obj) {
		if (obj.getSuperclassName().equals("java.lang.Thread")) return true;
		for(String s : obj.getInterfaceNames())
			if (s.equals("java.lang.Runnable")) return true;
		return false;
	}

}