org.checkerframework.common.value

Class ValueVisitor

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<ValueAnnotatedTypeFactory>

org.checkerframework.common.value.ValueVisitor

All Implemented Interfaces:

TreeVisitor<Void,Void>

public class ValueVisitor
extends BaseTypeVisitor<ValueAnnotatedTypeFactory>

Visitor for the Constant Value type system.

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

atypeFactory, checker, contractsUtils, positions, TARGET, targetValueElement, typeValidator, visitorState

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

elements, root, trees, treesWithSuppressWarnings, types

Constructor Summary

Constructors

Constructor and Description
ValueVisitor(BaseTypeChecker checker)

Method Summary

Modifier and Type	Method and Description
protected boolean	checkOverride(MethodTree overriderTree, AnnotatedTypeMirror.AnnotatedExecutableType overrider, AnnotatedTypeMirror.AnnotatedDeclaredType overridingType, AnnotatedTypeMirror.AnnotatedExecutableType overridden, AnnotatedTypeMirror.AnnotatedDeclaredType overriddenType) Return types for methods that are annotated with @IntRangeFromX annotations need to be replaced with @UnknownVal.
protected void	commonAssignmentCheck(AnnotatedTypeMirror varType, AnnotatedTypeMirror valueType, Tree valueTree, @CompilerMessageKey String errorKey, Object... extraArgs) Checks the validity of an assignment (or pseudo-assignment) from a value to a variable and emits an error message (through the compiler's messaging interface) if it is not valid.
protected void	commonAssignmentCheck(AnnotatedTypeMirror varType, ExpressionTree valueExp, @CompilerMessageKey String errorKey, Object... extraArgs) ValueVisitor overrides this method so that it does not have to check variables annotated with the IntRangeFromPositive annotation, the IntRangeFromNonNegative annotation, or the IntRangeFromGTENegativeOne annotation.
protected ValueAnnotatedTypeFactory	createTypeFactory() Constructs an instance of the appropriate type factory for the implemented type system.
boolean	validateType(Tree tree, AnnotatedTypeMirror type) Overridden to issue errors at the appropriate place if an IntRange or ArrayLenRange annotation has from > to.
Void	visitAnnotation(AnnotationTree node, Void p) Warns about malformed constant-value annotations.
Void	visitMethod(MethodTree node, Void p) Performs pseudo-assignment check: checks that the method obeys override and subtype rules to all overridden methods.
Void	visitTypeCast(TypeCastTree node, Void p)

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

checkAccess, checkArguments, checkArrayInitialization, checkConditionalPostcondition, checkConstructorInvocation, checkConstructorResult, checkContract, checkDefaultConstructor, checkExceptionParameter, checkExtendsImplements, checkFieldInvariantDeclarations, checkMethodInvocability, checkMethodReferenceAsOverride, checkOverride, checkPostcondition, checkPreconditions, checkPurity, checkQualifierParameter, checkSuperConstructorCall, checkThisConstructorCall, checkThisOrSuperConstructorCall, checkThrownExpression, checkTypeArguments, checkTypecastRedundancy, checkTypecastSafety, checkVarargs, commonAssignmentCheck, commonAssignmentCheckEndDiagnostic, commonAssignmentCheckEndDiagnostic, commonAssignmentCheckStartDiagnostic, createOverrideChecker, createTypeValidator, enclosingMemberSelect, enclosingStatement, getExceptionParameterLowerBoundAnnotations, getThrowUpperBoundAnnotations, getTypeFactory, isAccessAllowed, isTypeCastSafe, isValidUse, isValidUse, isValidUse, processClassTree, reportMethodInvocabilityError, reportPurityErrors, scan, setRoot, shouldSkipUses, skipReceiverSubtypeCheck, testTypevarContainment, typeCheckVectorCopyIntoArgument, validateTypeOf, visitArrayAccess, visitAssignment, visitCatch, visitClass, visitCompilationUnit, visitCompoundAssignment, visitConditionalExpression, visitEnhancedForLoop, visitIdentifier, visitInstanceOf, visitLambdaExpression, visitMemberReference, visitMethodInvocation, visitNewArray, visitNewClass, visitReturn, visitThrow, visitTypeParameter, visitUnary, visitVariable

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, visitAnnotatedType, visitArrayType, visitAssert, visitBinary, visitBlock, visitBreak, visitCase, visitContinue, visitDoWhileLoop, visitEmptyStatement, visitErroneous, visitExports, visitExpressionStatement, visitForLoop, visitIf, visitImport, visitIntersectionType, visitLabeledStatement, visitLiteral, visitMemberSelect, visitModifiers, visitModule, visitOpens, visitOther, visitPackage, visitParameterizedType, visitParenthesized, visitPrimitiveType, visitProvides, visitRequires, visitSwitch, visitSynchronized, visitTry, visitUnionType, visitUses, visitWhileLoop, visitWildcard

Methods inherited from class java.lang.Object

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

Constructor Detail

ValueVisitor

public ValueVisitor(BaseTypeChecker checker)

Method Detail

commonAssignmentCheck

protected void commonAssignmentCheck(AnnotatedTypeMirror varType,
                                     ExpressionTree valueExp,
                                     @CompilerMessageKey String errorKey,
                                     Object... extraArgs)

ValueVisitor overrides this method so that it does not have to check variables annotated with the IntRangeFromPositive annotation, the IntRangeFromNonNegative annotation, or the IntRangeFromGTENegativeOne annotation. This annotation is only introduced by the Index Checker's lower bound annotations. It is safe to defer checking of these values to the Index Checker because this is only introduced for explicitly-written org.checkerframework.checker.index.qual.Positive, explicitly-written org.checkerframework.checker.index.qual.NonNegative, and explicitly-written org.checkerframework.checker.index.qual.GTENegativeOne annotations, which must be checked by the Lower Bound Checker.

Overrides:

commonAssignmentCheck in class BaseTypeVisitor<ValueAnnotatedTypeFactory>

Parameters:

varType - the annotated type of the lvalue (usually a variable)

valueExp - the AST node for the rvalue (the new value)

errorKey - the error message key to use if the check fails

extraArgs - arguments to the error message key, before "found" and "expected" types

commonAssignmentCheck

protected void commonAssignmentCheck(AnnotatedTypeMirror varType,
                                     AnnotatedTypeMirror valueType,
                                     Tree valueTree,
                                     @CompilerMessageKey String errorKey,
                                     Object... extraArgs)

Description copied from class: BaseTypeVisitor

Checks the validity of an assignment (or pseudo-assignment) from a value to a variable and emits an error message (through the compiler's messaging interface) if it is not valid.

Overrides:

commonAssignmentCheck in class BaseTypeVisitor<ValueAnnotatedTypeFactory>

Parameters:

varType - the annotated type of the variable

valueType - the annotated type of the value

valueTree - the location to use when reporting the error message

errorKey - the error message key to use if the check fails

extraArgs - arguments to the error message key, before "found" and "expected" types

checkOverride

protected boolean checkOverride(MethodTree overriderTree,
                                AnnotatedTypeMirror.AnnotatedExecutableType overrider,
                                AnnotatedTypeMirror.AnnotatedDeclaredType overridingType,
                                AnnotatedTypeMirror.AnnotatedExecutableType overridden,
                                AnnotatedTypeMirror.AnnotatedDeclaredType overriddenType)

Return types for methods that are annotated with @IntRangeFromX annotations need to be replaced with @UnknownVal. See the documentation on commonAssignmentCheck.

A separate override is necessary because checkOverride doesn't actually use the commonAssignmentCheck.

Overrides:

checkOverride in class BaseTypeVisitor<ValueAnnotatedTypeFactory>

Parameters:

overriderTree - declaration tree of overriding method

overrider - type of the overriding method

overridingType - type of overriding class

overridden - type of overridden method

overriddenType - type of overridden class

Returns:

true if the override is allowed

See Also:

BaseTypeVisitor.checkOverride(MethodTree, AnnotatedTypeMirror.AnnotatedDeclaredType, AnnotatedTypeMirror.AnnotatedExecutableType, AnnotatedTypeMirror.AnnotatedDeclaredType)

createTypeFactory

protected ValueAnnotatedTypeFactory createTypeFactory()

Description copied from class: BaseTypeVisitor

Constructs an instance of the appropriate type factory for the implemented type system.

The default implementation uses the checker naming convention to create the appropriate type factory. If no factory is found, it returns BaseAnnotatedTypeFactory. It reflectively invokes the constructor that accepts this checker and 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:

createTypeFactory in class BaseTypeVisitor<ValueAnnotatedTypeFactory>

Returns:

the appropriate type factory

visitAnnotation

public Void visitAnnotation(AnnotationTree node,
                            Void p)

Warns about malformed constant-value annotations.

Issues an error if any @IntRange annotation has its 'from' value greater than 'to' value.

Issues an error if any constant-value annotation has no arguments.

Issues a warning if any constant-value annotation has > MAX_VALUES arguments.

Issues a warning if any @ArrayLen/@ArrayLenRange annotations contain a negative array length.

Specified by:

visitAnnotation in interface TreeVisitor<Void,Void>

Overrides:

visitAnnotation in class BaseTypeVisitor<ValueAnnotatedTypeFactory>

visitTypeCast

public Void visitTypeCast(TypeCastTree node,
                          Void p)

Specified by:

visitTypeCast in interface TreeVisitor<Void,Void>

Overrides:

visitTypeCast in class BaseTypeVisitor<ValueAnnotatedTypeFactory>

validateType

public boolean validateType(Tree tree,
                            AnnotatedTypeMirror type)

Overridden to issue errors at the appropriate place if an IntRange or ArrayLenRange annotation has from > to. from > to either indicates a user error when writing an annotation or an error in the checker's implementation, as from should always be <= to. Note that additional checks are performed in visitAnnotation(AnnotationTree, Void).

Overrides:

validateType in class BaseTypeVisitor<ValueAnnotatedTypeFactory>

Parameters:

tree - the type tree supplied by the user

type - the type corresponding to tree

See Also:

visitAnnotation(AnnotationTree, Void)

visitMethod

public Void visitMethod(MethodTree node,
                        Void p)

Description copied from class: BaseTypeVisitor

Performs pseudo-assignment check: checks that the method obeys override and subtype rules to all overridden methods.

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<ValueAnnotatedTypeFactory>