dumbmethods.java

A static analysis tool to find bugs in Java programs

			if (stackLoc >= 0) {
				OpcodeStack.Item tos = stack.getStackItem(stackLoc);
				switch (tos.getSpecialKind()) {
				case OpcodeStack.Item.HASHCODE_INT_REMAINDER:
					bugReporter.reportBug(new BugInstance(this, "RV_REM_OF_HASHCODE", HIGH_PRIORITY)
					.addClassAndMethod(this)
					.addSourceLine(this));
					break;
				case OpcodeStack.Item.RANDOM_INT:
				case OpcodeStack.Item.RANDOM_INT_REMAINDER:
					bugReporter.reportBug(new BugInstance(this, "RV_REM_OF_RANDOM_INT", HIGH_PRIORITY)
					.addClassAndMethod(this)
					.addSourceLine(this));
					break;
				}

			}
			if (seen == IREM) {
				OpcodeStack.Item item0 = stack.getStackItem(0);
				Object constant0 = item0.getConstant();
				OpcodeStack.Item item1 = stack.getStackItem(1);
				int special = item1.getSpecialKind();
				if (constant0 instanceof Integer && ((Integer)constant0).intValue() == 1)
					bugReporter.reportBug(new BugInstance(this, "INT_BAD_REM_BY_1", HIGH_PRIORITY)
					.addClassAndMethod(this)
					.addSourceLine(this));
			}

		if (stack.getStackDepth() >= 1 && (seen == LOOKUPSWITCH || seen == TABLESWITCH)) {
			OpcodeStack.Item item0 = stack.getStackItem(0);
			if (item0.getSpecialKind() == OpcodeStack.Item.SIGNED_BYTE) {
				int[] switchLabels = getSwitchLabels();
				int [] switchOffsets = getSwitchOffsets();
				for(int i = 0; i < switchLabels.length; i++) {
					int v = switchLabels[i];
					if (v <= -129 || v >= 128)
						bugReporter.reportBug(new BugInstance(this, "INT_BAD_COMPARISON_WITH_SIGNED_BYTE", 
								HIGH_PRIORITY)
									.addClassAndMethod(this)
									.addInt(v).describe(IntAnnotation.INT_VALUE)
									.addSourceLine(this, getPC() + switchOffsets[i]));

				}
			}
		}
		// check for use of signed byte where is it assumed it can be out of the -128...127 range
		if (stack.getStackDepth() >= 2) switch (seen) {
		case IF_ICMPEQ:
		case IF_ICMPNE:
		case IF_ICMPLT:
		case IF_ICMPLE:
		case IF_ICMPGE:
		case IF_ICMPGT:
			OpcodeStack.Item item0 = stack.getStackItem(0);
			OpcodeStack.Item item1 = stack.getStackItem(1);
			int seen2 = seen;
			if (item0.getConstant() != null) {
				OpcodeStack.Item tmp = item0;
				item0 = item1;
				item1 = tmp;
				switch(seen) {
				case IF_ICMPLT: 
					seen2 = IF_ICMPGT; break;
				case IF_ICMPGE:
					seen2 = IF_ICMPLE; break;
				case IF_ICMPGT: 
					seen2 = IF_ICMPLT; break;
				case IF_ICMPLE: 
					seen2 = IF_ICMPGE; break;

				}
			}
			Object constant1 = item1.getConstant();
			if (item0.getSpecialKind() == OpcodeStack.Item.SIGNED_BYTE
					&& constant1 instanceof Number) {
				int v1 = ((Number)constant1).intValue();
				if (v1 <= -129 || v1 >= 128 || v1 == 127 && !(seen2 == IF_ICMPEQ || seen2 == IF_ICMPNE 

						)) {
					int priority = HIGH_PRIORITY;
					if (v1 == 127) {
						switch(seen2) {
						case IF_ICMPGT: // 127 > x
							priority = LOW_PRIORITY; break;
						case IF_ICMPGE: // 127 >= x : always true
							priority = HIGH_PRIORITY; break;
						case IF_ICMPLT: // 127 < x : never true
							priority = HIGH_PRIORITY; break;
						case IF_ICMPLE: // 127 <= x 
							priority = LOW_PRIORITY; break;
						}
					} else if (v1 == 128) {
						switch(seen2) {
						case IF_ICMPGT: // 128 > x
							priority = NORMAL_PRIORITY; break;
						case IF_ICMPGE: // 128 >= x 
							priority = HIGH_PRIORITY; break;
						case IF_ICMPLT: // 128 < x
							priority = HIGH_PRIORITY; break;
						case IF_ICMPLE: // 128 <= x 
							priority = HIGH_PRIORITY; break;
						}
					} else if (v1 <= -129) priority = NORMAL_PRIORITY;


					bugReporter.reportBug(new BugInstance(this, "INT_BAD_COMPARISON_WITH_SIGNED_BYTE", priority)
								.addClassAndMethod(this)
								.addInt(v1).describe(IntAnnotation.INT_VALUE)
								.addSourceLine(this));
				}
			}	else       if (item0.getSpecialKind() == OpcodeStack.Item.MASKED_NON_NEGATIVE
					&& constant1 instanceof Number) {
				int v1 = ((Number)constant1).intValue();
				if (v1 < 0)  bugReporter.reportBug(new BugInstance(this, "INT_BAD_COMPARISON_WITH_NONNEGATIVE_VALUE", HIGH_PRIORITY)
								.addClassAndMethod(this)
								.addInt(v1).describe(IntAnnotation.INT_VALUE)
								.addSourceLine(this));

			}   

		}
		if (checkForBitIorofSignedByte && seen != I2B) {
			  bugReporter.reportBug(new BugInstance(this, "BIT_IOR_OF_SIGNED_BYTE", 
					prevOpcode == LOR ? HIGH_PRIORITY : NORMAL_PRIORITY)
						.addClassAndMethod(this)
						.addSourceLine(this));
			  checkForBitIorofSignedByte = false;
		} else if ((seen == IOR || seen == LOR) && stack.getStackDepth() >= 2) {
			OpcodeStack.Item item0 = stack.getStackItem(0);
			OpcodeStack.Item item1 = stack.getStackItem(1);

			int special0 = item0.getSpecialKind();
			int special1 = item1.getSpecialKind();
			if  (special0 == OpcodeStack.Item.SIGNED_BYTE  
					&& special1 == OpcodeStack.Item.LOW_8_BITS_CLEAR
					|| special0 == OpcodeStack.Item.LOW_8_BITS_CLEAR && special1 == OpcodeStack.Item.SIGNED_BYTE )
				checkForBitIorofSignedByte = true;
			else checkForBitIorofSignedByte = false;
		} else checkForBitIorofSignedByte = false;

	if (prevOpcodeWasReadLine && sinceBufferedInputStreamReady >= 100 && seen == INVOKEVIRTUAL
		&& getClassConstantOperand().equals("java/lang/String")
		&& getSigConstantOperand().startsWith("()")) {
		String method = getNameConstantOperand();
		String sig = getSigConstantOperand();
	  bugReporter.reportBug(new BugInstance(this, "NP_IMMEDIATE_DEREFERENCE_OF_READLINE", NORMAL_PRIORITY)
		.addClassAndMethod(this)
		.addSourceLine(this));
		}


	if 
		(seen == INVOKEVIRTUAL
		&& getClassConstantOperand().equals("java/io/BufferedReader")
		&& getNameConstantOperand().equals("ready")
		&& getSigConstantOperand().equals("()Z"))
		sinceBufferedInputStreamReady = 0;
	else sinceBufferedInputStreamReady++;

	prevOpcodeWasReadLine =
		(seen == INVOKEVIRTUAL||seen == INVOKEINTERFACE)
		&& getNameConstantOperand().equals("readLine")
		&& getSigConstantOperand().equals("()Ljava/lang/String;");

		// System.out.println(randomNextIntState + " " + OPCODE_NAMES[seen] + " " + getMethodName());
	switch(randomNextIntState) {
		case 0:
			if (seen == INVOKEVIRTUAL
				&& getClassConstantOperand().equals("java/util/Random")
				&& getNameConstantOperand().equals("nextDouble")
			   || seen == INVOKESTATIC
				&& getClassConstantOperand().equals("java/lang/Math")
				&& getNameConstantOperand().equals("random"))
			  randomNextIntState = 1;
			break;
		case 1:
			if (seen == D2I) {
			  bugReporter.reportBug(new BugInstance(this, "RV_01_TO_INT", HIGH_PRIORITY)
					.addClassAndMethod(this)
					.addSourceLine(this));
			  randomNextIntState = 0;
			  }
			else if (seen == DMUL) randomNextIntState = 4;
			else randomNextIntState = 2;
			break;
		case 2:
			if (seen == I2D) randomNextIntState = 3;
			else if (seen == DMUL) randomNextIntState = 4;
			else randomNextIntState = 0;
			break;
		case 3:
			if (seen == DMUL) randomNextIntState = 4;
			else randomNextIntState = 0;
			break;
		case 4:
			if (seen == D2I) 
			  bugReporter.reportBug(new BugInstance(this, "DM_NEXTINT_VIA_NEXTDOUBLE", NORMAL_PRIORITY)
					.addClassAndMethod(this)
					.addSourceLine(this));
			randomNextIntState = 0;
			break;
		default:
			throw new IllegalStateException();
			}
		if (isPublicStaticVoidMain && seen == INVOKEVIRTUAL
				&& getClassConstantOperand().startsWith("javax/swing/")
				&& (getNameConstantOperand().equals("show")
				&& getSigConstantOperand().equals("()V")
				|| getNameConstantOperand().equals("pack")
				&& getSigConstantOperand().equals("()V")
				|| getNameConstantOperand().equals("setVisible")
				&& getSigConstantOperand().equals("(Z)V")))
			bugReporter.reportBug(new BugInstance(this, "SW_SWING_METHODS_INVOKED_IN_SWING_THREAD", LOW_PRIORITY)
					.addClassAndMethod(this)
					.addSourceLine(this));

//		if ((seen == INVOKEVIRTUAL)
//				&& getClassConstantOperand().equals("java/lang/String")
//				&& getNameConstantOperand().equals("substring")
//				&& getSigConstantOperand().equals("(I)Ljava/lang/String;")
//				&& stack.getStackDepth() > 1) {
//			OpcodeStack.Item item = stack.getStackItem(0);
//			Object o = item.getConstant();
//			if (o != null && o instanceof Integer) {
//				int v = ((Integer) o).intValue();
//				if (v == 0)
//					bugReporter.reportBug(new BugInstance(this, "DMI_USELESS_SUBSTRING", NORMAL_PRIORITY)
//					        .addClassAndMethod(this)
//					        .addSourceLine(this));
//			}
//		}

		if ((seen == INVOKEVIRTUAL)
				&& getNameConstantOperand().equals("isAnnotationPresent")
				&& getSigConstantOperand().equals("(Ljava/lang/Class;)Z")
				&& stack.getStackDepth() > 0) {
			OpcodeStack.Item item = stack.getStackItem(0);
			Object value = item.getConstant();
			if (value instanceof String) {
				String annotationClassName = (String) value;
				boolean lacksClassfileRetention 
				= AnalysisContext.currentAnalysisContext().getAnnotationRetentionDatabase().lacksClassfileRetention(
						annotationClassName.replace('/','.'));
				if (lacksClassfileRetention) 
					bugReporter.reportBug(new BugInstance(this, "DMI_ANNOTATION_IS_NOT_VISIBLE_TO_REFLECTION",
						HIGH_PRIORITY)
						.addClassAndMethod(this)
						.addSourceLine(this)
						.addCalledMethod(this));
			}

		}
		if ((seen == INVOKEVIRTUAL)
				&& getNameConstantOperand().equals("next")
				&& getSigConstantOperand().equals("()Ljava/lang/Object;")
				&& getMethodName().equals("hasNext")
				&& getMethodSig().equals("()Z")
				&& stack.getStackDepth() > 0) {
			OpcodeStack.Item item = stack.getStackItem(0);

				bugReporter.reportBug(new BugInstance(this, "DMI_CALLING_NEXT_FROM_HASNEXT",
						item.isInitialParameter() && item.getRegisterNumber() == 0 ? NORMAL_PRIORITY : LOW_PRIORITY)
						.addClassAndMethod(this)
						.addSourceLine(this)
						.addCalledMethod(this));

		}


		if ((seen == INVOKESPECIAL)
				&& getClassConstantOperand().equals("java/lang/String")
				&& getNameConstantOperand().equals("<init>")
				&& getSigConstantOperand().equals("(Ljava/lang/String;)V"))
			if (alreadyReported.add(getRefConstantOperand()))
				bugReporter.reportBug(new BugInstance(this, "DM_STRING_CTOR", NORMAL_PRIORITY)
						.addClassAndMethod(this)
						.addSourceLine(this));
		if (seen == INVOKESTATIC
				&& getClassConstantOperand().equals("java/lang/System")
				&& getNameConstantOperand().equals("runFinalizersOnExit")
			|| seen == INVOKEVIRTUAL
				&& getClassConstantOperand().equals("java/lang/Runtime")
				&& getNameConstantOperand().equals("runFinalizersOnExit"))
				bugReporter.reportBug(new BugInstance(this, "DM_RUN_FINALIZERS_ON_EXIT", HIGH_PRIORITY)
						.addClassAndMethod(this)
						.addSourceLine(this));
		if ((seen == INVOKESPECIAL)