Package org.checkerframework.dataflow.util

Class PurityChecker.PurityCheckerHelper

java.lang.Object

com.sun.source.util.TreeScanner<Void,Void>

com.sun.source.util.TreePathScanner<Void,Void>

org.checkerframework.dataflow.util.PurityChecker.PurityCheckerHelper

All Implemented Interfaces:

TreeVisitor<Void,Void>

Enclosing class:

PurityChecker

protected static class PurityChecker.PurityCheckerHelper
extends TreePathScanner<Void,Void>

Helper class to keep PurityChecker's interface clean.

The scanner is run on statements and on the class members that contain code that runs during construction (a field declaration or an initializer block). It is not run on a class or method declaration.

Field Summary

Fields

Modifier and Type	Field	Description
protected final AnnotationProvider	annoProvider	The annotation provider (typically an AnnotatedTypeFactory).

Constructor Summary

Constructors

Constructor	Description
PurityCheckerHelper(AnnotationProvider annoProvider, boolean assumeSideEffectFree, boolean assumeDeterministic, boolean assumePureGetters)	Create a PurityCheckerHelper.

Method Summary

Modifier and Type	Method	Description
protected void	assignmentCheck(ExpressionTree variable)	Returns true if variable is permitted on the left-hand-side of an assignment.
protected boolean	isLocalVariable(ExpressionTree variable)	Checks if the argument is a local variable.
Void	visitAssignment(AssignmentTree tree, Void ignore)
Void	visitCatch(CatchTree tree, Void ignore)
Void	visitClass(ClassTree tree, Void ignore)	Declaring a local or anonymous class has no side effect.
Void	visitCompoundAssignment(CompoundAssignmentTree tree, Void ignore)
Void	visitLambdaExpression(LambdaExpressionTree tree, Void ignore)	Evaluating a lambda expression creates an object; it does not run the lambda's body.
Void	visitMemberReference(MemberReferenceTree tree, Void ignore)	Evaluating a method reference creates an object; it does not run the referenced method.
Void	visitMethodInvocation(MethodInvocationTree tree, Void ignore)
Void	visitNewClass(NewClassTree tree, Void ignore)
Void	visitUnary(UnaryTree tree, Void ignore)

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

getCurrentPath, scan, scan

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

reduce, scan, visitAnnotatedType, visitAnnotation, visitAnyPattern, visitArrayAccess, visitArrayType, visitAssert, visitBinary, visitBindingPattern, visitBlock, visitBreak, visitCase, visitCompilationUnit, visitConditionalExpression, visitConstantCaseLabel, visitContinue, visitDeconstructionPattern, visitDefaultCaseLabel, visitDoWhileLoop, visitEmptyStatement, visitEnhancedForLoop, visitErroneous, visitExports, visitExpressionStatement, visitForLoop, visitIdentifier, visitIf, visitImport, visitInstanceOf, visitIntersectionType, visitLabeledStatement, visitLiteral, visitMemberSelect, visitMethod, visitModifiers, visitModule, visitNewArray, visitOpens, visitOther, visitPackage, visitParameterizedType, visitParenthesized, visitPatternCaseLabel, visitPrimitiveType, visitProvides, visitRequires, visitReturn, visitStringTemplate, visitSwitch, visitSwitchExpression, visitSynchronized, visitThrow, visitTry, visitTypeCast, visitTypeParameter, visitUnionType, visitUses, visitVariable, visitWhileLoop, visitWildcard, visitYield

Methods inherited from class java.lang.Object

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

Field Details

annoProvider

protected final AnnotationProvider annoProvider

The annotation provider (typically an AnnotatedTypeFactory).

Constructor Details

PurityCheckerHelper

public PurityCheckerHelper(AnnotationProvider annoProvider,
 boolean assumeSideEffectFree,
 boolean assumeDeterministic,
 boolean assumePureGetters)

Create a PurityCheckerHelper.

Parameters:

annoProvider - the annotation provider

assumeSideEffectFree - true if all methods should be assumed to be @SideEffectFree

assumeDeterministic - true if all methods should be assumed to be @Deterministic

assumePureGetters - true if getter methods should be assumed to be @Pure

Method Details

visitCatch

public Void visitCatch(CatchTree tree,
 Void ignore)

Specified by:

visitCatch in interface TreeVisitor<Void,Void>

Overrides:

visitCatch in class TreeScanner<Void,Void>

visitLambdaExpression

public Void visitLambdaExpression(LambdaExpressionTree tree,
 Void ignore)

Evaluating a lambda expression creates an object; it does not run the lambda's body.

Creating an object is not deterministic, just as a new expression is not; see visitNewClass(com.sun.source.tree.NewClassTree, java.lang.Void).

The body's effects occur where the lambda's functional method is invoked, and that invocation is checked like any other method call. Therefore, do not scan the body. The body is checked elsewhere, against the purity annotations on the functional method that the lambda implements; see BaseTypeVisitor#checkLambdaPurity.

Specified by:

visitLambdaExpression in interface TreeVisitor<Void,Void>

Overrides:

visitLambdaExpression in class TreeScanner<Void,Void>

Parameters:

tree - a lambda expression

ignore - an unused parameter

Returns:

null

visitMemberReference

public Void visitMemberReference(MemberReferenceTree tree,
 Void ignore)

Evaluating a method reference creates an object; it does not run the referenced method.

Creating an object is not deterministic, just as a new expression is not; see visitNewClass(com.sun.source.tree.NewClassTree, java.lang.Void). JLS 15.13.3 leaves it unspecified whether two evaluations of the same method reference produce the same object.

The referenced method's effects occur where the functional method is invoked, and that invocation is checked like any other method call.

Do scan the children. The qualifier expression of EXPR::m is evaluated where the method reference appears, unlike the body of a lambda.

Specified by:

visitMemberReference in interface TreeVisitor<Void,Void>

Overrides:

visitMemberReference in class TreeScanner<Void,Void>

Parameters:

tree - a method reference

ignore - an unused parameter

Returns:

null

visitClass

public Void visitClass(ClassTree tree,
 Void ignore)

Declaring a local or anonymous class has no side effect. The class's methods are checked against their own purity annotations, like the methods of any other class.

Do scan the class's non-method members. Attributing a field initializer or an initializer block to the method that contains the class declaration is conservative: the effect is reported even if the class is never instantiated.

Specified by:

visitClass in interface TreeVisitor<Void,Void>

Overrides:

visitClass in class TreeScanner<Void,Void>

Parameters:

tree - a class declaration

ignore - an unused parameter

Returns:

null

visitMethodInvocation

public Void visitMethodInvocation(MethodInvocationTree tree,
 Void ignore)

Specified by:

visitMethodInvocation in interface TreeVisitor<Void,Void>

Overrides:

visitMethodInvocation in class TreeScanner<Void,Void>

visitNewClass

public Void visitNewClass(NewClassTree tree,
 Void ignore)

Specified by:

visitNewClass in interface TreeVisitor<Void,Void>

Overrides:

visitNewClass in class TreeScanner<Void,Void>

visitAssignment

public Void visitAssignment(AssignmentTree tree,
 Void ignore)

Specified by:

visitAssignment in interface TreeVisitor<Void,Void>

Overrides:

visitAssignment in class TreeScanner<Void,Void>

visitUnary

public Void visitUnary(UnaryTree tree,
 Void ignore)

Specified by:

visitUnary in interface TreeVisitor<Void,Void>

Overrides:

visitUnary in class TreeScanner<Void,Void>

assignmentCheck

protected void assignmentCheck(ExpressionTree variable)

Returns true if variable is permitted on the left-hand-side of an assignment.

Parameters:

variable - the lhs to check

isLocalVariable

protected boolean isLocalVariable(ExpressionTree variable)

Checks if the argument is a local variable.

Parameters:

variable - the tree to check

Returns:

true if the argument is a local variable

visitCompoundAssignment

public Void visitCompoundAssignment(CompoundAssignmentTree tree,
 Void ignore)

Specified by:

visitCompoundAssignment in interface TreeVisitor<Void,Void>

Overrides:

visitCompoundAssignment in class TreeScanner<Void,Void>