checkers.nullness
Class NullnessVisitor

java.lang.Object
  com.sun.source.util.TreeScanner<R,P>
      com.sun.source.util.TreePathScanner<R,P>
          checkers.source.SourceVisitor<R,P>
              checkers.basetype.BaseTypeVisitor<Void,Void>
                  checkers.nullness.NullnessVisitor

All Implemented Interfaces:

TreeVisitor<Void,Void>

public class NullnessVisitor
extends BaseTypeVisitor<Void,Void>

A type-checking visitor for the Nullness type system. This visitor reports errors ("dereference.of.nullable") or warnings for violations for the following cases: 1. if the receiver of a member dereference is not NonNull 2. if the receiver of an implicit ".iterator()" dereference in an enhanced for loop is not NonNull 3. if an accessed array is not NonNull Self-accesses (via this or super) can always be dereferenced.

See Also:

NullnessChecker

Field Summary

Fields inherited from class checkers.basetype.BaseTypeVisitor

annoFactory, annoTypes, checker, visitorState

Fields inherited from class checkers.source.SourceVisitor

atypeFactory, elements, root, trees, types

Constructor Summary

NullnessVisitor(NullnessChecker checker, CompilationUnitTree root)
Creates a new visitor for type-checking NonNull.

Method Summary

protected boolean	checkMethodInvocability(AnnotatedTypeMirror.AnnotatedExecutableType method, MethodInvocationTree node) Tests whether the method can be invoked using the receiver of the 'node' method invocation, and issues a "method.invocation.invalid" if the invocation is invalid.
Void	visitArrayAccess(ArrayAccessTree node, Void p)
Void	visitEnhancedForLoop(EnhancedForLoopTree node, Void p) Performs a subtype check, to test whether the node expression iterable type is a subtype of the variable type in the enhanced for loop.
Void	visitMemberSelect(MemberSelectTree node, Void p)
Void	visitThrow(ThrowTree node, Void p)

Methods inherited from class checkers.basetype.BaseTypeVisitor

checkArguments, checkAssignability, checkOverride, checkTypeArguments, commonAssignmentCheck, commonAssignmentCheck, commonAssignmentCheck, scan, shouldSkip, shouldSkip, validateTypeOf, visitAnnotation, visitAssignment, visitClass, visitCompilationUnit, visitCompoundAssignment, visitInstanceOf, visitMethod, visitMethodInvocation, visitNewArray, visitNewClass, visitParameterizedType, visitReturn, visitTypeCast, visitUnary, visitVariable

Methods inherited from class com.sun.source.util.TreePathScanner

getCurrentPath, scan

Methods inherited from class com.sun.source.util.TreeScanner

reduce, scan, visitAnnotatedType, visitArrayType, visitAssert, visitBinary, visitBlock, visitBreak, visitCase, visitCatch, visitConditionalExpression, visitContinue, visitDoWhileLoop, visitEmptyStatement, visitErroneous, visitExpressionStatement, visitForLoop, visitIdentifier, visitIf, visitImport, visitLabeledStatement, visitLiteral, visitModifiers, visitOther, visitParenthesized, visitPrimitiveType, visitSwitch, visitSynchronized, visitTry, visitTypeParameter, visitWhileLoop, visitWildcard

Methods inherited from class java.lang.Object

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

Constructor Detail

NullnessVisitor

public NullnessVisitor(NullnessChecker checker,
                       CompilationUnitTree root)

Creates a new visitor for type-checking NonNull.

Parameters:

checker - the checker to use

root - the root of the input program's AST to check

Method Detail

visitMemberSelect

public Void visitMemberSelect(MemberSelectTree node,
                              Void p)

Specified by:

visitMemberSelect in interface TreeVisitor<Void,Void>

Overrides:

visitMemberSelect in class TreeScanner<Void,Void>

visitEnhancedForLoop

public Void visitEnhancedForLoop(EnhancedForLoopTree node,
                                 Void p)

Description copied from class: BaseTypeVisitor

Performs a subtype check, to test whether the node expression iterable type is a subtype of the variable type in the enhanced for loop. If the subtype check fails, it issues a "type.incompatible" error.

Specified by:

visitEnhancedForLoop in interface TreeVisitor<Void,Void>

Overrides:

visitEnhancedForLoop in class BaseTypeVisitor<Void,Void>

visitArrayAccess

public Void visitArrayAccess(ArrayAccessTree node,
                             Void p)

Specified by:

visitArrayAccess in interface TreeVisitor<Void,Void>

Overrides:

visitArrayAccess in class TreeScanner<Void,Void>

visitThrow

public Void visitThrow(ThrowTree node,
                       Void p)

Specified by:

visitThrow in interface TreeVisitor<Void,Void>

Overrides:

visitThrow in class TreeScanner<Void,Void>

checkMethodInvocability

protected boolean checkMethodInvocability(AnnotatedTypeMirror.AnnotatedExecutableType method,
                                          MethodInvocationTree node)

Description copied from class: BaseTypeVisitor

Tests whether the method can be invoked using the receiver of the 'node' method invocation, and issues a "method.invocation.invalid" if the invocation is invalid. This implementation tests whether the receiver in the method invocation is a subtype of the method receiver type.

Overrides:

checkMethodInvocability in class BaseTypeVisitor<Void,Void>

Parameters:

method - the type of the invoked method

node - the method invocation node

Returns:

true iff the call of 'node' is a valid call