org.eclipse.jdt.internal.compiler.ast.NullLiteral Java Examples

/** Generates 'this.<em>name</em>.size()' as an expression; if nullGuard is true, it's this.name == null ? 0 : this.name.size(). */
protected Expression getSize(EclipseNode builderType, char[] name, boolean nullGuard) {
	MessageSend invoke = new MessageSend();
	ThisReference thisRef = new ThisReference(0, 0);
	FieldReference thisDotName = new FieldReference(name, 0L);
	thisDotName.receiver = thisRef;
	invoke.receiver = thisDotName;
	invoke.selector = SIZE_TEXT;
	if (!nullGuard) return invoke;
	
	ThisReference cdnThisRef = new ThisReference(0, 0);
	FieldReference cdnThisDotName = new FieldReference(name, 0L);
	cdnThisDotName.receiver = cdnThisRef;
	NullLiteral nullLiteral = new NullLiteral(0, 0);
	EqualExpression isNull = new EqualExpression(cdnThisDotName, nullLiteral, OperatorIds.EQUAL_EQUAL);
	IntLiteral zeroLiteral = makeIntLiteral(new char[] {'0'}, null);
	ConditionalExpression conditional = new ConditionalExpression(isNull, zeroLiteral, invoke);
	return conditional;
}
 

public char[] returnVarNameIfNullCheck(Statement stat) {
	if (!(stat instanceof IfStatement)) return null;
	
	/* Check that the if's statement is a throw statement, possibly in a block. */ {
		Statement then = ((IfStatement) stat).thenStatement;
		if (then instanceof Block) {
			Statement[] blockStatements = ((Block) then).statements;
			if (blockStatements == null || blockStatements.length == 0) return null;
			then = blockStatements[0];
		}
		
		if (!(then instanceof ThrowStatement)) return null;
	}
	
	/* Check that the if's conditional is like 'x == null'. Return from this method (don't generate
	   a nullcheck) if 'x' is equal to our own variable's name: There's already a nullcheck here. */ {
		Expression cond = ((IfStatement) stat).condition;
		if (!(cond instanceof EqualExpression)) return null;
		EqualExpression bin = (EqualExpression) cond;
		int operatorId = ((bin.bits & ASTNode.OperatorMASK) >> ASTNode.OperatorSHIFT);
		if (operatorId != OperatorIds.EQUAL_EQUAL) return null;
		if (!(bin.left instanceof SingleNameReference)) return null;
		if (!(bin.right instanceof NullLiteral)) return null;
		return ((SingleNameReference) bin.left).token;
	}
}
 

protected Statement createConstructBuilderVarIfNeeded(SingularData data, EclipseNode builderType) {
	FieldReference thisDotField = new FieldReference(data.getPluralName(), 0L);
	thisDotField.receiver = new ThisReference(0, 0);
	FieldReference thisDotField2 = new FieldReference(data.getPluralName(), 0L);
	thisDotField2.receiver = new ThisReference(0, 0);
	Expression cond = new EqualExpression(thisDotField, new NullLiteral(0, 0), OperatorIds.EQUAL_EQUAL);
	
	MessageSend createBuilderInvoke = new MessageSend();
	char[][] tokenizedName = makeGuavaTypeName(getSimpleTargetTypeName(data), false);
	createBuilderInvoke.receiver = new QualifiedNameReference(tokenizedName, NULL_POSS, 0, 0);
	createBuilderInvoke.selector = getBuilderMethodName(data);
	return new IfStatement(cond, new Assignment(thisDotField2, createBuilderInvoke, 0), 0, 0);
}
 

/**
 * Generates a new statement that checks if the given variable is null, and if so, throws a specified exception with the
 * variable name as message.
 * 
 * @param exName The name of the exception to throw; normally {@code java.lang.NullPointerException}.
 */
public static Statement generateNullCheck(AbstractVariableDeclaration variable, EclipseNode sourceNode) {
	NullCheckExceptionType exceptionType = sourceNode.getAst().readConfiguration(ConfigurationKeys.NON_NULL_EXCEPTION_TYPE);
	if (exceptionType == null) exceptionType = NullCheckExceptionType.NULL_POINTER_EXCEPTION;
	
	ASTNode source = sourceNode.get();
	
	int pS = source.sourceStart, pE = source.sourceEnd;
	long p = (long)pS << 32 | pE;
	
	if (isPrimitive(variable.type)) return null;
	AllocationExpression exception = new AllocationExpression();
	setGeneratedBy(exception, source);
	int partCount = 1;
	String exceptionTypeStr = exceptionType.getExceptionType();
	for (int i = 0; i < exceptionTypeStr.length(); i++) if (exceptionTypeStr.charAt(i) == '.') partCount++;
	long[] ps = new long[partCount];
	Arrays.fill(ps, 0L);
	exception.type = new QualifiedTypeReference(fromQualifiedName(exceptionTypeStr), ps);
	setGeneratedBy(exception.type, source);
	exception.arguments = new Expression[] {
			new StringLiteral(exceptionType.toExceptionMessage(new String(variable.name)).toCharArray(), pS, pE, 0)
	};
	setGeneratedBy(exception.arguments[0], source);
	ThrowStatement throwStatement = new ThrowStatement(exception, pS, pE);
	setGeneratedBy(throwStatement, source);
	
	SingleNameReference varName = new SingleNameReference(variable.name, p);
	setGeneratedBy(varName, source);
	NullLiteral nullLiteral = new NullLiteral(pS, pE);
	setGeneratedBy(nullLiteral, source);
	EqualExpression equalExpression = new EqualExpression(varName, nullLiteral, OperatorIds.EQUAL_EQUAL);
	equalExpression.sourceStart = pS; equalExpression.statementEnd = equalExpression.sourceEnd = pE;
	setGeneratedBy(equalExpression, source);
	Block throwBlock = new Block(0);
	throwBlock.statements = new Statement[] {throwStatement};
	throwBlock.sourceStart = pS; throwBlock.sourceEnd = pE;
	setGeneratedBy(throwBlock, source);
	IfStatement ifStatement = new IfStatement(equalExpression, throwBlock, 0, 0);
	setGeneratedBy(ifStatement, source);
	return ifStatement;
}
 

@Override public boolean visit(NullLiteral node, BlockScope scope) {
	fixPositions(setGeneratedBy(node, source));
	return super.visit(node, scope);
}
 

public boolean visit(NullLiteral nullLiteral, BlockScope scope) {
	addRealFragment(nullLiteral);
	return false;
}
 

protected Object getMemberValue(org.eclipse.jdt.internal.core.MemberValuePair memberValuePair, Expression expression) {
	if (expression instanceof NullLiteral) {
		return null;
	} else if (expression instanceof Literal) {
		((Literal) expression).computeConstant();
		return Util.getAnnotationMemberValue(memberValuePair, expression.constant);
	} else if (expression instanceof org.eclipse.jdt.internal.compiler.ast.Annotation) {
		org.eclipse.jdt.internal.compiler.ast.Annotation annotation = (org.eclipse.jdt.internal.compiler.ast.Annotation) expression;
		Object handle = acceptAnnotation(annotation, null, (JavaElement) this.handleStack.peek());
		memberValuePair.valueKind = IMemberValuePair.K_ANNOTATION;
		return handle;
	} else if (expression instanceof ClassLiteralAccess) {
		ClassLiteralAccess classLiteral = (ClassLiteralAccess) expression;
		char[] name = CharOperation.concatWith(classLiteral.type.getTypeName(), '.');
		memberValuePair.valueKind = IMemberValuePair.K_CLASS;
		return new String(name);
	} else if (expression instanceof QualifiedNameReference) {
		char[] qualifiedName = CharOperation.concatWith(((QualifiedNameReference) expression).tokens, '.');
		memberValuePair.valueKind = IMemberValuePair.K_QUALIFIED_NAME;
		return new String(qualifiedName);
	} else if (expression instanceof SingleNameReference) {
		char[] simpleName = ((SingleNameReference) expression).token;
		if (simpleName == RecoveryScanner.FAKE_IDENTIFIER) {
			memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
			return null;
		}
		memberValuePair.valueKind = IMemberValuePair.K_SIMPLE_NAME;
		return new String(simpleName);
	} else if (expression instanceof ArrayInitializer) {
		memberValuePair.valueKind = -1; // modified below by the first call to getMemberValue(...)
		Expression[] expressions = ((ArrayInitializer) expression).expressions;
		int length = expressions == null ? 0 : expressions.length;
		Object[] values = new Object[length];
		for (int i = 0; i < length; i++) {
			int previousValueKind = memberValuePair.valueKind;
			Object value = getMemberValue(memberValuePair, expressions[i]);
			if (previousValueKind != -1 && memberValuePair.valueKind != previousValueKind) {
				// values are heterogeneous, value kind is thus unknown
				memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
			}
			values[i] = value;
		}
		if (memberValuePair.valueKind == -1)
			memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
		return values;
	} else if (expression instanceof UnaryExpression) {			// to deal with negative numerals (see bug - 248312)
		UnaryExpression unaryExpression = (UnaryExpression) expression;
		if ((unaryExpression.bits & ASTNode.OperatorMASK) >> ASTNode.OperatorSHIFT == OperatorIds.MINUS) {
			if (unaryExpression.expression instanceof Literal) {
				Literal subExpression = (Literal) unaryExpression.expression;
				subExpression.computeConstant();
				return Util.getNegativeAnnotationMemberValue(memberValuePair, subExpression.constant);
			}
		}
		memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
		return null;
	} else {
		memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
		return null;
	}
}
 

private Object getAnnotationMemberValue(MemberValuePair memberValuePair, Expression expression, JavaElement parentElement) {
	if (expression instanceof NullLiteral) {
		return null;
	} else if (expression instanceof Literal) {
		((Literal) expression).computeConstant();
		return Util.getAnnotationMemberValue(memberValuePair, expression.constant);
	} else if (expression instanceof org.eclipse.jdt.internal.compiler.ast.Annotation) {
		memberValuePair.valueKind = IMemberValuePair.K_ANNOTATION;
		return getAnnotation((org.eclipse.jdt.internal.compiler.ast.Annotation) expression, parentElement);
	} else if (expression instanceof ClassLiteralAccess) {
		ClassLiteralAccess classLiteral = (ClassLiteralAccess) expression;
		char[] typeName = CharOperation.concatWith(classLiteral.type.getTypeName(), '.');
		memberValuePair.valueKind = IMemberValuePair.K_CLASS;
		return new String(typeName);
	} else if (expression instanceof QualifiedNameReference) {
		char[] qualifiedName = CharOperation.concatWith(((QualifiedNameReference) expression).tokens, '.');
		memberValuePair.valueKind = IMemberValuePair.K_QUALIFIED_NAME;
		return new String(qualifiedName);
	} else if (expression instanceof SingleNameReference) {
		char[] simpleName = ((SingleNameReference) expression).token;
		if (simpleName == RecoveryScanner.FAKE_IDENTIFIER) {
			memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
			return null;
		}
		memberValuePair.valueKind = IMemberValuePair.K_SIMPLE_NAME;
		return new String(simpleName);
	} else if (expression instanceof ArrayInitializer) {
		memberValuePair.valueKind = -1; // modified below by the first call to getMemberValue(...)
		Expression[] expressions = ((ArrayInitializer) expression).expressions;
		int length = expressions == null ? 0 : expressions.length;
		Object[] values = new Object[length];
		for (int i = 0; i < length; i++) {
			int previousValueKind = memberValuePair.valueKind;
			Object value = getAnnotationMemberValue(memberValuePair, expressions[i], parentElement);
			if (previousValueKind != -1 && memberValuePair.valueKind != previousValueKind) {
				// values are heterogeneous, value kind is thus unknown
				memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
			}
			values[i] = value;
		}
		if (memberValuePair.valueKind == -1)
			memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
		return values;
	} else if (expression instanceof UnaryExpression) {			//to deal with negative numerals (see bug - 248312)
		UnaryExpression unaryExpression = (UnaryExpression) expression;
		if ((unaryExpression.bits & ASTNode.OperatorMASK) >> ASTNode.OperatorSHIFT == OperatorIds.MINUS) {
			if (unaryExpression.expression instanceof Literal) {
				Literal subExpression = (Literal) unaryExpression.expression;
				subExpression.computeConstant();
				return Util.getNegativeAnnotationMemberValue(memberValuePair, subExpression.constant);
			}
		}
		memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
		return null;
	} else {
		memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
		return null;
	}
}