org.checkerframework.checker.nullness

Class NullnessChecker

java.lang.Object

javax.annotation.processing.AbstractProcessor

org.checkerframework.javacutil.AbstractTypeProcessor

org.checkerframework.framework.source.SourceChecker

org.checkerframework.common.basetype.BaseTypeChecker

org.checkerframework.checker.initialization.InitializationChecker

org.checkerframework.checker.nullness.NullnessChecker

All Implemented Interfaces:

Processor, BaseTypeContext, BaseContext, CFContext, OptionConfiguration

@SupportedLintOptions(value={"noInitForMonotonicNonNull","redundantNullComparison","soundArrayCreationNullness","forbidnonnullarraycomponents","trustArrayLenZero","permitClearProperty"})
public class NullnessChecker
extends InitializationChecker

An implementation of the nullness type-system, parameterized by an initialization type-system for safe initialization. It uses freedom-before-commitment, augmented by type frames (which are crucial to obtain acceptable precision), as its initialization type system.

See the Checker Framework Manual:

Nullness Checker

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	LINT_DEFAULT_NOINITFORMONOTONICNONNULL Default for LINT_NOINITFORMONOTONICNONNULL.
static boolean	LINT_DEFAULT_PERMITCLEARPROPERTY Default for LINT_PERMITCLEARPROPERTY.
static boolean	LINT_DEFAULT_REDUNDANTNULLCOMPARISON Default for LINT_REDUNDANTNULLCOMPARISON.
static boolean	LINT_DEFAULT_TRUSTARRAYLENZERO Default for LINT_TRUSTARRAYLENZERO.
static String	LINT_NOINITFORMONOTONICNONNULL Should we be strict about initialization of MonotonicNonNull variables?
static String	LINT_PERMITCLEARPROPERTY If true, client code may clear system properties.
static String	LINT_REDUNDANTNULLCOMPARISON Warn about redundant comparisons of expressions with null, if the expressions is known to be non-null.
static String	LINT_TRUSTARRAYLENZERO Should the Nullness Checker unsoundly trust @ArrayLen(0) annotations to improve handling of Collection.toArray() by CollectionToArrayHeuristics?

Fields inherited from class org.checkerframework.framework.source.SourceChecker

currentRoot, DETAILS_SEPARATOR, elementsWithSuppressedWarnings, errsOnLastExit, messager, messagesProperties, MSGS_FILE, OPTION_SEPARATOR, parentChecker, SUPPRESS_ALL_MESSAGE_KEY, SUPPRESS_ALL_PREFIX, trees, UNNEEDED_SUPPRESSION_KEY, upstreamCheckerNames, visitor

Fields inherited from class javax.annotation.processing.AbstractProcessor

processingEnv

Constructor Summary

Constructors

Constructor and Description
NullnessChecker()

Method Summary

Modifier and Type	Method and Description
protected BaseTypeVisitor<?>	createSourceVisitor() Returns the appropriate visitor that type-checks the compilation unit according to the type system rules.
protected LinkedHashSet<Class<? extends BaseTypeChecker>>	getImmediateSubcheckerClasses() Returns the set of subchecker classes on which this checker depends.
SortedSet<String>	getSuppressWarningsPrefixes() Returns a modifiable set of lower-case strings that are prefixes for SuppressWarnings strings.

Methods inherited from class org.checkerframework.checker.initialization.InitializationChecker

getAllFields

Methods inherited from class org.checkerframework.common.basetype.BaseTypeChecker

getAnnotationProvider, getChecker, getContext, getOptions, getRelatedClassName, getSubchecker, getSubcheckers, getSupportedLintOptions, getSupportedOptions, getTreePathCacher, getTypeFactory, getTypeFactoryOfSubchecker, getVisitor, initChecker, invokeConstructorFor, printOrStoreMessage, processArg, setRoot, shouldAddShutdownHook, shouldResolveReflection, shutdownHook, typeProcess, typeProcessingOver, warnUnneededSuppressions

Methods inherited from class org.checkerframework.framework.source.SourceChecker

addOptions, createSupportedLintOptions, expandCFOptions, fullMessageOf, getBooleanOption, getBooleanOption, getElementUtils, getLintOption, getLintOption, getMessagesProperties, getOption, getOption, getOptionConfiguration, getParentChecker, getProcessingEnvironment, getProperties, getStandardSuppressWarningsPrefixes, getSupportedAnnotationTypes, getSupportedSourceVersion, getTreeUtils, getTypeUtils, getUpstreamCheckerNames, hasOption, init, message, printOrStoreMessage, printStats, report, reportError, reportWarning, setLintOption, setParentChecker, setProcessingEnvironment, setSupportedLintOptions, shouldSkipDefs, shouldSkipDefs, shouldSkipUses, shouldSkipUses, shouldSuppressWarnings, shouldSuppressWarnings, typeProcessingStart, useConservativeDefault, warnUnneededSuppressions

Methods inherited from class org.checkerframework.javacutil.AbstractTypeProcessor

getCompilerLog, process

Methods inherited from class javax.annotation.processing.AbstractProcessor

getCompletions, isInitialized

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.checkerframework.framework.util.BaseContext

getElementUtils, getOptionConfiguration, getProcessingEnvironment, getTreeUtils, getTypeUtils

Field Detail

LINT_NOINITFORMONOTONICNONNULL

public static final String LINT_NOINITFORMONOTONICNONNULL

Should we be strict about initialization of MonotonicNonNull variables?

See Also:

Constant Field Values

LINT_DEFAULT_NOINITFORMONOTONICNONNULL

public static final boolean LINT_DEFAULT_NOINITFORMONOTONICNONNULL

Default for LINT_NOINITFORMONOTONICNONNULL.

See Also:

Constant Field Values

LINT_REDUNDANTNULLCOMPARISON

public static final String LINT_REDUNDANTNULLCOMPARISON

Warn about redundant comparisons of expressions with null, if the expressions is known to be non-null.

See Also:

Constant Field Values

LINT_DEFAULT_REDUNDANTNULLCOMPARISON

public static final boolean LINT_DEFAULT_REDUNDANTNULLCOMPARISON

Default for LINT_REDUNDANTNULLCOMPARISON.

See Also:

Constant Field Values

LINT_TRUSTARRAYLENZERO

public static final String LINT_TRUSTARRAYLENZERO

Should the Nullness Checker unsoundly trust @ArrayLen(0) annotations to improve handling of Collection.toArray() by CollectionToArrayHeuristics?

See Also:

Constant Field Values

LINT_DEFAULT_TRUSTARRAYLENZERO

public static final boolean LINT_DEFAULT_TRUSTARRAYLENZERO

Default for LINT_TRUSTARRAYLENZERO.

See Also:

Constant Field Values

LINT_PERMITCLEARPROPERTY

public static final String LINT_PERMITCLEARPROPERTY

If true, client code may clear system properties. If false (the default), some calls to System.getProperty are refined to return @NonNull.

See Also:

Constant Field Values

LINT_DEFAULT_PERMITCLEARPROPERTY

public static final boolean LINT_DEFAULT_PERMITCLEARPROPERTY

Default for LINT_PERMITCLEARPROPERTY.

See Also:

Constant Field Values

Constructor Detail

NullnessChecker

public NullnessChecker()

Method Detail

getImmediateSubcheckerClasses

protected LinkedHashSet<Class<? extends BaseTypeChecker>> getImmediateSubcheckerClasses()

Description copied from class: BaseTypeChecker

Returns the set of subchecker classes on which this checker depends. Returns an empty set if this checker does not depend on any others.

Subclasses should override this method to specify subcheckers. If they do so, they should call the super implementation of this method and add dependencies to the returned set so that checkers required for reflection resolution are included if reflection resolution is requested.

Each subchecker of this checker may also depend on other checkers. If this checker and one of its subcheckers both depend on a third checker, that checker will only be instantiated once.

Though each checker is run on a whole compilation unit before the next checker is run, error and warning messages are collected and sorted based on the location in the source file before being printed. (See BaseTypeChecker.printOrStoreMessage(Diagnostic.Kind, String, Tree, CompilationUnitTree).)

WARNING: Circular dependencies are not supported nor do checkers verify that their dependencies are not circular. Make sure no circular dependencies are created when overriding this method. (In other words, if checker A depends on checker B, checker B cannot depend on checker A.)

This method is protected so it can be overridden, but it should only be called internally by the BaseTypeChecker.

The BaseTypeChecker will not modify the list returned by this method.

Overrides:

getImmediateSubcheckerClasses in class BaseTypeChecker

getSuppressWarningsPrefixes

public SortedSet<String> getSuppressWarningsPrefixes()

Description copied from class: SourceChecker

Returns a modifiable set of lower-case strings that are prefixes for SuppressWarnings strings.

The collection must not be empty and must not contain only SourceChecker.SUPPRESS_ALL_PREFIX.

Overrides:

getSuppressWarningsPrefixes in class InitializationChecker

Returns:

non-empty modifiable set of lower-case prefixes for SuppressWarnings strings

createSourceVisitor

protected BaseTypeVisitor<?> createSourceVisitor()

Description copied from class: BaseTypeChecker

Returns the appropriate visitor that type-checks the compilation unit according to the type system rules.

This implementation uses the checker naming convention to create the appropriate visitor. If no visitor is found, it returns an instance of BaseTypeVisitor. It reflectively invokes the constructor that accepts this checker and the compilation unit tree (in that order) as arguments.

Subclasses have to override this method to create the appropriate visitor if they do not follow the checker naming convention.

Overrides:

createSourceVisitor in class BaseTypeChecker

Returns:

the type-checking visitor