Package org.checkerframework.checker.nonempty

Class NonEmptyChecker

java.lang.Object
javax.annotation.processing.AbstractProcessor
org.checkerframework.javacutil.AbstractTypeProcessor
org.checkerframework.framework.source.SourceChecker
org.checkerframework.common.basetype.BaseTypeChecker
org.checkerframework.checker.nonempty.NonEmptyChecker
All Implemented Interfaces:
Processor, OptionConfiguration
public class NonEmptyChecker extends BaseTypeChecker
A type-checker that prevents NoSuchElementException in the use of container classes.

Runs the OptionalImplChecker (as a subchecker) by default. This checker should not yet be run as a standalone checker. The Non-Empty Checker uses explicitly-written (i.e., programmer-written) annotations from the Non-Empty type system to refine the analysis of operations on containers (e.g., Streams, Collections) that result in values of type Optional.

See the Checker Framework Manual:
Non-Empty Checker

  • Constructor Details

    • NonEmptyChecker

      public NonEmptyChecker()
      Creates a NonEmptyChecker.

  • Method Details

    • getImmediateSubcheckerClasses

      protected Set<Class<? extends SourceChecker>> getImmediateSubcheckerClasses()
      Description copied from class: SourceChecker
      Returns the set of subchecker classes on which this checker depends. ("Depends" means the checkers that are subcheckers of the current checker rather than a subchecker of some other checker.) Returns an empty set if this checker does not depend on any others.

      If this checker should run multiple independent checkers and not contain a type system, then subclass AggregateChecker.

      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.

      If a checker should be added or not based on a command line option, use SourceChecker.getOptionsNoSubcheckers() or SourceChecker.hasOptionNoSubcheckers(String) to avoid recursively calling this method.

      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 SourceChecker.printOrStoreMessage(Diagnostic.Kind, String, Tree, CompilationUnitTree).)

      WARNING: Circular dependencies are not supported. (In other words, if checker A depends on checker B, checker B cannot depend on checker A.) The Checker Framework does not check for circularity. Make sure no circular dependencies are created when overriding this method.

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

      Overrides:
      getImmediateSubcheckerClasses in class SourceChecker
      Returns:
      the subchecker classes on which this checker depends; will be modified by callees

    • shouldSkipDefs

      public boolean shouldSkipDefs(MethodTree tree)
      Description copied from class: SourceChecker
      Tests whether the method definition should not be checked because it matches the checker.skipDefs property.
      Overrides:
      shouldSkipDefs in class SourceChecker
      Parameters:
      tree - method to potentially skip
      Returns:
      true if checker should not type-check tree