Package org.checkerframework.checker.signedness

Class SignednessVisitor

java.lang.Object

com.sun.source.util.TreeScanner<R,P>

com.sun.source.util.TreePathScanner<R,P>

org.checkerframework.framework.source.SourceVisitor<Void,Void>

org.checkerframework.common.basetype.BaseTypeVisitor<SignednessAnnotatedTypeFactory>

org.checkerframework.checker.signedness.SignednessVisitor

All Implemented Interfaces:

TreeVisitor<Void,Void>

public class SignednessVisitor
extends BaseTypeVisitor<SignednessAnnotatedTypeFactory>

The SignednessVisitor enforces the Signedness Checker rules. These rules are described in the Checker Framework Manual.

See the Checker Framework Manual:

Signedness Checker

Nested Class Summary

Nested classes/interfaces inherited from class org.checkerframework.common.basetype.BaseTypeVisitor

BaseTypeVisitor.OverrideChecker

Field Summary

Fields inherited from class org.checkerframework.common.basetype.BaseTypeVisitor

assumePureGetters, atypeFactory, checker, DETERMINISTIC, IMPURE, methodTree, positions, PURE, qualHierarchy, showchecks, SIDE_EFFECT_FREE, TARGET, targetValueElement, typeHierarchy, typeValidator, unusedWhenElement

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

elements, root, trees, treesWithSuppressWarnings, types

Constructor Summary

Constructors

Constructor	Description
SignednessVisitor(BaseTypeChecker checker)

Method Summary

Modifier and Type	Method	Description
protected void	checkConstructorResult(AnnotatedTypeMirror.AnnotatedExecutableType constructorType, ExecutableElement constructorElement)	Issue a warning if the result type of the constructor declaration is not top.
protected AnnotationMirrorSet	getExceptionParameterLowerBoundAnnotations()	Returns a set of AnnotationMirrors that is a lower bound for exception parameters.
protected boolean	isTypeCastSafe(AnnotatedTypeMirror castType, AnnotatedTypeMirror exprType)	Returns true if the cast is safe.
Void	visitBinary(BinaryTree tree, Void p)	Enforces the following rules on binary operations involving Unsigned and Signed types: Do not allow any Unsigned types or PolySigned types in {/, %} operations.
Void	visitCompoundAssignment(CompoundAssignmentTree tree, Void p)	Enforces the following rules on compound assignments involving Unsigned and Signed types: Do not allow any Unsigned types or PolySigned types in {/=, %=} assignments.
Void	visitMethod(MethodTree tree, Void p)	Checks that the method or constructor obeys override and subtype rules to all overridden methods.
Void	visitMethodInvocation(MethodInvocationTree tree, Void p)	Performs a method invocation check.

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

checkAccess, checkAccessAllowed, checkArguments, checkArrayInitialization, checkConditionalPostcondition, checkConstructorInvocation, checkContract, checkDefaultConstructor, checkExceptionParameter, checkExplicitAnnotationsOnIntersectionBounds, checkExtendsAndImplements, checkExtendsOrImplements, checkFieldInvariantDeclarations, checkMethodInvocability, checkMethodReferenceAsOverride, checkOverride, checkOverride, checkPostcondition, checkPreconditions, checkPurityAnnotations, checkQualifierParameter, checkSuperConstructorCall, checkThisConstructorCall, checkThisOrSuperConstructorCall, checkThrownExpression, checkTypeArguments, checkTypecastRedundancy, checkTypecastSafety, checkVarargs, commonAssignmentCheck, commonAssignmentCheck, commonAssignmentCheck, commonAssignmentCheckEndDiagnostic, commonAssignmentCheckEndDiagnostic, commonAssignmentCheckStartDiagnostic, contractExpressionAndType, createOverrideChecker, createTypeFactory, createTypeFactoryPublic, createTypeValidator, enclosingMemberSelect, enclosingStatement, getThrowUpperBoundAnnotations, getTypeFactory, isValidUse, isValidUse, isValidUse, processClassTree, reportMethodInvocabilityError, reportPurityErrors, scan, setRoot, shouldPerformContractInference, shouldSkipUses, shouldWarnAboutIrrelevantJavaTypes, skipReceiverSubtypeCheck, testAnnotationInsertion, testJointJavacJavaParserVisitor, testTypevarContainment, typeCheckVectorCopyIntoArgument, validateType, validateTypeOf, visitAnnotatedType, visitAnnotatedType, visitAnnotation, visitAssignment, visitCatch, visitClass, visitCompilationUnit, visitConditionalExpression, visitEnhancedForLoop, visitIdentifier, visitInstanceOf, visitLambdaExpression, visitMemberReference, visitNewArray, visitNewClass, visitReturn, visitSwitchExpression17, visitThrow, visitTypeCast, visitTypeParameter, visitUnary, visitVariable, warnAboutIrrelevantJavaTypes, warnInvalidPolymorphicQualifier, warnInvalidPolymorphicQualifier, warnRedundantAnnotations

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

visit

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

getCurrentPath, scan

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

reduce, scan, visitArrayAccess, visitArrayType, visitAssert, visitBindingPattern, visitBlock, visitBreak, visitCase, visitContinue, visitDefaultCaseLabel, visitDoWhileLoop, visitEmptyStatement, visitErroneous, visitExports, visitExpressionStatement, visitForLoop, visitGuardedPattern, visitIf, visitImport, visitIntersectionType, visitLabeledStatement, visitLiteral, visitMemberSelect, visitModifiers, visitModule, visitOpens, visitOther, visitPackage, visitParameterizedType, visitParenthesized, visitParenthesizedPattern, visitPrimitiveType, visitProvides, visitRequires, visitSwitch, visitSwitchExpression, visitSynchronized, visitTry, visitUnionType, visitUses, visitWhileLoop, visitWildcard, visitYield

Methods inherited from class java.lang.Object

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

Constructor Details

SignednessVisitor

public SignednessVisitor(BaseTypeChecker checker)

Method Details

visitBinary

public Void visitBinary(BinaryTree tree,
 Void p)

Enforces the following rules on binary operations involving Unsigned and Signed types:

• Do not allow any Unsigned types or PolySigned types in {/, %} operations.
• Do not allow signed right shift {>>} on an Unsigned type or a PolySigned type.
• Do not allow unsigned right shift {>>>} on a Signed type or a PolySigned type.
• Allow any left shift {<<}.
• Do not allow non-equality comparisons {<, <=, >, >=} on Unsigned types or PolySigned types.
• Do not allow the mixing of Signed and Unsigned types.

Specified by:

visitBinary in interface TreeVisitor<Void,Void>

Overrides:

visitBinary in class TreeScanner<Void,Void>

visitMethod

public Void visitMethod(MethodTree tree,
 Void p)

Description copied from class: BaseTypeVisitor

Checks that the method or constructor obeys override and subtype rules to all overridden methods. (Uses the pseudo-assignment logic to do so.)

The override rule specifies that a method, m1, may override a method m2 only if:

• m1 return type is a subtype of m2
• m1 receiver type is a supertype of m2
• m1 parameters are supertypes of corresponding m2 parameters

Also, it issues a "missing.this" error for static method annotated receivers.

Specified by:

visitMethod in interface TreeVisitor<Void,Void>

Overrides:

visitMethod in class BaseTypeVisitor<SignednessAnnotatedTypeFactory>

visitMethodInvocation

public Void visitMethodInvocation(MethodInvocationTree tree,
 Void p)

Description copied from class: BaseTypeVisitor

Performs a method invocation check.

An invocation of a method, m, on the receiver, r is valid only if:

• passed arguments are subtypes of corresponding m parameters
• r is a subtype of m receiver type
• if m is generic, passed type arguments are subtypes of m type variables

Specified by:

visitMethodInvocation in interface TreeVisitor<Void,Void>

Overrides:

visitMethodInvocation in class BaseTypeVisitor<SignednessAnnotatedTypeFactory>

visitCompoundAssignment

public Void visitCompoundAssignment(CompoundAssignmentTree tree,
 Void p)

Enforces the following rules on compound assignments involving Unsigned and Signed types:

• Do not allow any Unsigned types or PolySigned types in {/=, %=} assignments.
• Do not allow signed right shift {>>=} to assign to an Unsigned type or a PolySigned type.
• Do not allow unsigned right shift {>>>=} to assign to a Signed type or a PolySigned type.
• Allow any left shift {<<=} assignment.
• Do not allow mixing of Signed and Unsigned types.

Specified by:

visitCompoundAssignment in interface TreeVisitor<Void,Void>

Overrides:

visitCompoundAssignment in class BaseTypeVisitor<SignednessAnnotatedTypeFactory>

isTypeCastSafe

protected boolean isTypeCastSafe(AnnotatedTypeMirror castType,
 AnnotatedTypeMirror exprType)

Description copied from class: BaseTypeVisitor

Returns true if the cast is safe.

Only primary qualifiers are checked unless the command line option "checkCastElementType" is supplied.

Overrides:

isTypeCastSafe in class BaseTypeVisitor<SignednessAnnotatedTypeFactory>

Parameters:

castType - annotated type of the cast

exprType - annotated type of the casted expression

Returns:

true if the type cast is safe, false otherwise

getExceptionParameterLowerBoundAnnotations

protected AnnotationMirrorSet getExceptionParameterLowerBoundAnnotations()

Description copied from class: BaseTypeVisitor

Returns a set of AnnotationMirrors that is a lower bound for exception parameters.

This implementation returns top; subclasses can change this behavior.

Note: by default this method is called by BaseTypeVisitor.getThrowUpperBoundAnnotations(), so that this annotation is enforced.

Overrides:

getExceptionParameterLowerBoundAnnotations in class BaseTypeVisitor<SignednessAnnotatedTypeFactory>

Returns:

set of annotation mirrors, one per hierarchy, that form a lower bound of annotations that can be written on an exception parameter

checkConstructorResult

protected void checkConstructorResult(AnnotatedTypeMirror.AnnotatedExecutableType constructorType,
 ExecutableElement constructorElement)

Description copied from class: BaseTypeVisitor

Issue a warning if the result type of the constructor declaration is not top. If it is a supertype of the class, then a conflicting.annos error will also be issued by BaseTypeVisitor.isValidUse(AnnotatedTypeMirror.AnnotatedDeclaredType,AnnotatedTypeMirror.AnnotatedDeclaredType,Tree).

Overrides:

checkConstructorResult in class BaseTypeVisitor<SignednessAnnotatedTypeFactory>

Parameters:

constructorType - the AnnotatedExecutableType for the constructor

constructorElement - the element that declares the constructor