org.checkerframework.javacutil

Class TreeUtils

java.lang.Object

org.checkerframework.javacutil.TreeUtils

public final class TreeUtils
extends java.lang.Object

A utility class made for helping to analyze a given Tree.

Method Summary

Modifier and Type	Method and Description
static boolean	canHaveTypeAnnotation(com.sun.source.tree.Tree tree)
static java.util.Set<com.sun.source.tree.Tree.Kind>	classTreeKinds()
static boolean	containsThisConstructorInvocation(com.sun.source.tree.MethodTree node)
static javax.lang.model.element.TypeElement	elementFromDeclaration(com.sun.source.tree.ClassTree node) Gets the element for a class corresponding to a declaration.
static javax.lang.model.element.ExecutableElement	elementFromDeclaration(com.sun.source.tree.MethodTree node) Gets the element for a method corresponding to a declaration.
static javax.lang.model.element.VariableElement	elementFromDeclaration(com.sun.source.tree.VariableTree node) Gets the element for a variable corresponding to its declaration.
static javax.lang.model.element.Element	elementFromUse(com.sun.source.tree.ExpressionTree node) Gets the element for the declaration corresponding to this use of an element.
static javax.lang.model.element.ExecutableElement	elementFromUse(com.sun.source.tree.MethodInvocationTree node)
static javax.lang.model.element.ExecutableElement	elementFromUse(com.sun.source.tree.NewClassTree node)
static @Nullable com.sun.source.tree.ClassTree	enclosingClass(@Nullable com.sun.source.util.TreePath path) Gets the enclosing class of the tree node defined by the given TreePath.
static @Nullable com.sun.source.tree.MethodTree	enclosingMethod(@Nullable com.sun.source.util.TreePath path) Gets the enclosing method of the tree node defined by the given TreePath.
static <T extends com.sun.source.tree.Tree> T	enclosingOfClass(com.sun.source.util.TreePath path, java.lang.Class<T> treeClass) Gets the first enclosing tree in path, of the specified class
static com.sun.source.tree.Tree	enclosingOfKind(com.sun.source.util.TreePath path, java.util.Set<com.sun.source.tree.Tree.Kind> kinds) Gets the first enclosing tree in path, with any one of the specified kinds.
static com.sun.source.tree.Tree	enclosingOfKind(com.sun.source.util.TreePath path, com.sun.source.tree.Tree.Kind kind) Gets the first enclosing tree in path, of the specified kind.
static @Nullable com.sun.source.tree.BlockTree	enclosingTopLevelBlock(com.sun.source.util.TreePath path)
static com.sun.source.tree.VariableTree	enclosingVariable(com.sun.source.util.TreePath path) Gets the enclosing variable of a tree node defined by the given TreePath.
static com.sun.source.tree.Tree	firstStatement(com.sun.source.tree.Tree tree)
static com.sun.source.tree.Tree	getAssignmentContext(com.sun.source.util.TreePath treePath) Returns the tree with the assignment context for the treePath leaf node.
static javax.lang.model.element.VariableElement	getField(java.lang.String typeName, java.lang.String fieldName, javax.annotation.processing.ProcessingEnvironment env) Returns the VariableElement for a field declaration.
static java.lang.String	getFieldName(com.sun.source.tree.Tree tree) Compute the name of the field that the field access tree accesses.
static javax.lang.model.element.ExecutableElement	getMethod(java.lang.String typeName, java.lang.String methodName, int params, javax.annotation.processing.ProcessingEnvironment env) Returns the ExecutableElement for the method declaration of methodName, in class typeName, with params formal parameters.
static javax.lang.model.element.ExecutableElement	getMethod(java.lang.String typeName, java.lang.String methodName, javax.annotation.processing.ProcessingEnvironment env, java.lang.String... paramTypes) Returns the ExecutableElement for a method declaration of methodName, in class typeName, with formal parameters of the given types.
static java.util.List<javax.lang.model.element.ExecutableElement>	getMethodList(java.lang.String typeName, java.lang.String methodName, int params, javax.annotation.processing.ProcessingEnvironment env) Returns all ExecutableElements for method declarations of methodName, in class typeName, with params formal parameters.
static java.lang.String	getMethodName(com.sun.source.tree.Tree tree) Compute the name of the method that the method access tree accesses.
static com.sun.source.tree.ExpressionTree	getReceiverTree(com.sun.source.tree.ExpressionTree expression) Returns the receiver tree of a field access or a method invocation
static boolean	hasExplicitConstructor(com.sun.source.tree.ClassTree node) Determine whether the given class contains an explicit constructor.
static boolean	isArrayLengthAccess(com.sun.source.tree.Tree tree) Returns whether or not tree is an access of array length.
static boolean	isClassLiteral(com.sun.source.tree.Tree tree) Determine whether tree is a class literal, such as
static boolean	isClassTree(com.sun.source.tree.Tree tree) Is the given tree kind a class, i.e.
static boolean	isCompileTimeString(com.sun.source.tree.ExpressionTree node) Returns true if the node is a constant-time expression.
static boolean	isConstructor(com.sun.source.tree.MethodTree tree) Checks if the provided method is a constructor method or no.
static boolean	isDiamondTree(com.sun.source.tree.Tree tree) Returns true if the tree is of a diamond type.
static boolean	isEnumSuper(com.sun.source.tree.MethodInvocationTree node)
static boolean	isExplicitThisDereference(com.sun.source.tree.ExpressionTree tree) Determine whether the given expression is either "this" or an outer "C.this".
static boolean	isExpressionTree(com.sun.source.tree.Tree tree) Determine whether the given tree represents an ExpressionTree.
static boolean	isFieldAccess(com.sun.source.tree.Tree tree) Determine whether tree is a field access expressions, such as
static boolean	isGetClassInvocation(com.sun.source.tree.MethodInvocationTree invocationTree)
static boolean	isMethodAccess(com.sun.source.tree.Tree tree) Determine whether tree refers to a method element, such as
static boolean	isMethodInvocation(com.sun.source.tree.Tree tree, javax.lang.model.element.ExecutableElement method, javax.annotation.processing.ProcessingEnvironment env) Returns true if the given element is an invocation of the method, or of any method that overrides that one.
protected static boolean	isNamedMethodCall(java.lang.String name, com.sun.source.tree.MethodInvocationTree tree)
static boolean	isSelfAccess(com.sun.source.tree.ExpressionTree tree) Returns true if the tree is a tree that 'looks like' either an access of a field or an invocation of a method that are owned by the same accessing instance.
static boolean	isSpecificFieldAccess(com.sun.source.tree.Tree tree, javax.lang.model.element.VariableElement var) Returns true if and only if the given tree represents a field access of the given VariableElement.
static boolean	isStringCompoundConcatenation(com.sun.source.tree.CompoundAssignmentTree tree) Returns true if the compound assignment tree is a string concatenation
static boolean	isStringConcatenation(com.sun.source.tree.Tree tree) Returns true if the tree represents a String concatenation operation
static boolean	isSuperCall(com.sun.source.tree.MethodInvocationTree tree) Checks if the method invocation is a call to super.
static boolean	isThisCall(com.sun.source.tree.MethodInvocationTree tree) Checks if the method invocation is a call to this.
static boolean	isTreeInStaticScope(com.sun.source.util.TreePath path) Returns whether or not the leaf of the tree path is in a static scope.
static boolean	isTypeDeclaration(com.sun.source.tree.Tree node) Determine whether the given tree represents a declaration of a type (including type parameters).
static boolean	isTypeTree(com.sun.source.tree.Tree tree) Is the given tree a type instantiation?
static boolean	isUseOfElement(com.sun.source.tree.ExpressionTree node) Determine whether the given ExpressionTree has an underlying element.
static javax.lang.model.element.Name	methodName(com.sun.source.tree.MethodInvocationTree node)
static com.sun.source.util.TreePath	pathTillClass(com.sun.source.util.TreePath path) Gets path to the first enclosing class tree, where class is defined by the classTreeKinds method.
static com.sun.source.util.TreePath	pathTillOfKind(com.sun.source.util.TreePath path, java.util.Set<com.sun.source.tree.Tree.Kind> kinds) Gets path to the first enclosing tree with any one of the specified kinds.
static com.sun.source.util.TreePath	pathTillOfKind(com.sun.source.util.TreePath path, com.sun.source.tree.Tree.Kind kind) Gets path to the first enclosing tree of the specified kind.
static com.sun.source.tree.ExpressionTree	skipParens(com.sun.source.tree.ExpressionTree tree) If the given tree is a parenthesized tree, it returns the enclosed non-parenthesized tree.
static java.util.Set<com.sun.source.tree.Tree.Kind>	typeTreeKinds()

Methods inherited from class java.lang.Object

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

Method Detail

isConstructor

public static boolean isConstructor(com.sun.source.tree.MethodTree tree)

Checks if the provided method is a constructor method or no.

Parameters:

tree - a tree defining the method

Returns:

true iff tree describes a constructor

isSuperCall

public static boolean isSuperCall(com.sun.source.tree.MethodInvocationTree tree)

Checks if the method invocation is a call to super.

Parameters:

tree - a tree defining a method invocation

Returns:

true iff tree describes a call to super

isThisCall

public static boolean isThisCall(com.sun.source.tree.MethodInvocationTree tree)

Checks if the method invocation is a call to this.

Parameters:

tree - a tree defining a method invocation

Returns:

true iff tree describes a call to this

isNamedMethodCall

protected static boolean isNamedMethodCall(java.lang.String name,
                                           com.sun.source.tree.MethodInvocationTree tree)

isSelfAccess

public static boolean isSelfAccess(com.sun.source.tree.ExpressionTree tree)

Returns true if the tree is a tree that 'looks like' either an access of a field or an invocation of a method that are owned by the same accessing instance.

It would only return true if the access tree is of the form:

   field
   this.field

   method()
   this.method()
 

It does not perform any semantical check to differentiate between fields and local variables; local methods or imported static methods.

Parameters:

tree - expression tree representing an access to object member

Returns:

true iff the member is a member of this instance

enclosingOfKind

public static com.sun.source.tree.Tree enclosingOfKind(com.sun.source.util.TreePath path,
                                                       com.sun.source.tree.Tree.Kind kind)

Gets the first enclosing tree in path, of the specified kind.

Parameters:

path - the path defining the tree node

kind - the kind of the desired tree

Returns:

the enclosing tree of the given type as given by the path

enclosingOfKind

public static com.sun.source.tree.Tree enclosingOfKind(com.sun.source.util.TreePath path,
                                                       java.util.Set<com.sun.source.tree.Tree.Kind> kinds)

Gets the first enclosing tree in path, with any one of the specified kinds.

Parameters:

path - the path defining the tree node

kinds - the set of kinds of the desired tree

Returns:

the enclosing tree of the given type as given by the path

pathTillClass

public static com.sun.source.util.TreePath pathTillClass(com.sun.source.util.TreePath path)

Gets path to the first enclosing class tree, where class is defined by the classTreeKinds method.

Parameters:

path - the path defining the tree node

Returns:

the path to the enclosing class tree

pathTillOfKind

public static com.sun.source.util.TreePath pathTillOfKind(com.sun.source.util.TreePath path,
                                                          com.sun.source.tree.Tree.Kind kind)

Gets path to the first enclosing tree of the specified kind.

Parameters:

path - the path defining the tree node

kind - the kind of the desired tree

Returns:

the path to the enclosing tree of the given type

pathTillOfKind

public static com.sun.source.util.TreePath pathTillOfKind(com.sun.source.util.TreePath path,
                                                          java.util.Set<com.sun.source.tree.Tree.Kind> kinds)

Gets path to the first enclosing tree with any one of the specified kinds.

Parameters:

path - the path defining the tree node

kinds - the set of kinds of the desired tree

Returns:

the path to the enclosing tree of the given type

enclosingOfClass

public static <T extends com.sun.source.tree.Tree> T enclosingOfClass(com.sun.source.util.TreePath path,
                                                                      java.lang.Class<T> treeClass)

Gets the first enclosing tree in path, of the specified class

Parameters:

path - the path defining the tree node

treeClass - the class of the desired tree

Returns:

the enclosing tree of the given type as given by the path

enclosingClass

public static @Nullable com.sun.source.tree.ClassTree enclosingClass(@Nullable com.sun.source.util.TreePath path)

Gets the enclosing class of the tree node defined by the given TreePath. It returns a Tree, from which checkers.types.AnnotatedTypeMirror or Element can be obtained.

Parameters:

path - the path defining the tree node

Returns:

the enclosing class (or interface) as given by the path, or null if one does not exist

enclosingVariable

public static com.sun.source.tree.VariableTree enclosingVariable(com.sun.source.util.TreePath path)

Gets the enclosing variable of a tree node defined by the given TreePath.

Parameters:

path - the path defining the tree node

Returns:

the enclosing variable as given by the path, or null if one does not exist

enclosingMethod

public static @Nullable com.sun.source.tree.MethodTree enclosingMethod(@Nullable com.sun.source.util.TreePath path)

Gets the enclosing method of the tree node defined by the given TreePath. It returns a Tree, from which an checkers.types.AnnotatedTypeMirror or Element can be obtained.

Parameters:

path - the path defining the tree node

Returns:

the enclosing method as given by the path, or null if one does not exist

enclosingTopLevelBlock

public static @Nullable com.sun.source.tree.BlockTree enclosingTopLevelBlock(com.sun.source.util.TreePath path)

skipParens

public static com.sun.source.tree.ExpressionTree skipParens(com.sun.source.tree.ExpressionTree tree)

If the given tree is a parenthesized tree, it returns the enclosed non-parenthesized tree. Otherwise, it returns the same tree.

Parameters:

tree - an expression tree

Returns:

the outermost non-parenthesized tree enclosed by the given tree

getAssignmentContext

public static com.sun.source.tree.Tree getAssignmentContext(com.sun.source.util.TreePath treePath)

Returns the tree with the assignment context for the treePath leaf node. (Does not handle pseudo-assignment of an argument to a parameter or a receiver expression to a receiver.)

The assignment context for the treePath is the leaf of its parent, if the parent is one of the following trees:

• AssignmentTree
• CompoundAssignmentTree
• MethodInvocationTree
• NewArrayTree
• NewClassTree
• ReturnTree
• VariableTree

If the parent is a ConditionalExpressionTree we need to distinguish two cases: If the leaf is either the then or else branch of the ConditionalExpressionTree, then recurse on the parent. If the leaf is the condition of the ConditionalExpressionTree, then return null to not consider this assignment context.

If the leaf is a ParenthesizedTree, then recurse on the parent.

Otherwise, null is returned.

Returns:

the assignment context as described

elementFromDeclaration

public static final javax.lang.model.element.TypeElement elementFromDeclaration(com.sun.source.tree.ClassTree node)

Gets the element for a class corresponding to a declaration.

Returns:

the element for the given class

elementFromDeclaration

public static final javax.lang.model.element.ExecutableElement elementFromDeclaration(com.sun.source.tree.MethodTree node)

Gets the element for a method corresponding to a declaration.

Returns:

the element for the given method

elementFromDeclaration

public static final javax.lang.model.element.VariableElement elementFromDeclaration(com.sun.source.tree.VariableTree node)

Gets the element for a variable corresponding to its declaration.

Returns:

the element for the given variable

elementFromUse

public static final javax.lang.model.element.Element elementFromUse(com.sun.source.tree.ExpressionTree node)

Gets the element for the declaration corresponding to this use of an element. To get the element for a declaration, use Trees.getElement(TreePath) instead.

TODO: remove this method, as it really doesn't do anything.

Parameters:

node - the tree corresponding to a use of an element

Returns:

the element for the corresponding declaration

elementFromUse

public static final javax.lang.model.element.ExecutableElement elementFromUse(com.sun.source.tree.MethodInvocationTree node)

elementFromUse

public static final javax.lang.model.element.ExecutableElement elementFromUse(com.sun.source.tree.NewClassTree node)

isUseOfElement

public static final boolean isUseOfElement(com.sun.source.tree.ExpressionTree node)

Determine whether the given ExpressionTree has an underlying element.

Parameters:

node - the ExpressionTree to test

Returns:

whether the tree refers to an identifier, member select, or method invocation

methodName

public static final javax.lang.model.element.Name methodName(com.sun.source.tree.MethodInvocationTree node)

Returns:

the name of the invoked method

containsThisConstructorInvocation

public static final boolean containsThisConstructorInvocation(com.sun.source.tree.MethodTree node)

Returns:

true if the first statement in the body is a self constructor invocation within a constructor

firstStatement

public static final com.sun.source.tree.Tree firstStatement(com.sun.source.tree.Tree tree)

hasExplicitConstructor

public static boolean hasExplicitConstructor(com.sun.source.tree.ClassTree node)

Determine whether the given class contains an explicit constructor.

Parameters:

node - a class tree

Returns:

true, iff there is an explicit constructor

isDiamondTree

public static final boolean isDiamondTree(com.sun.source.tree.Tree tree)

Returns true if the tree is of a diamond type. In contrast to the implementation in TreeInfo, this version works on Trees.

See Also:

TreeInfo.isDiamond(JCTree)

isStringConcatenation

public static final boolean isStringConcatenation(com.sun.source.tree.Tree tree)

Returns true if the tree represents a String concatenation operation

isStringCompoundConcatenation

public static final boolean isStringCompoundConcatenation(com.sun.source.tree.CompoundAssignmentTree tree)

Returns true if the compound assignment tree is a string concatenation

isCompileTimeString

public static boolean isCompileTimeString(com.sun.source.tree.ExpressionTree node)

Returns true if the node is a constant-time expression.

A tree is a constant-time expression if it is:

1. a literal tree
2. a reference to a final variable initialized with a compile time constant
3. a String concatenation of two compile time constants

getReceiverTree

public static com.sun.source.tree.ExpressionTree getReceiverTree(com.sun.source.tree.ExpressionTree expression)

Returns the receiver tree of a field access or a method invocation

classTreeKinds

public static java.util.Set<com.sun.source.tree.Tree.Kind> classTreeKinds()

isClassTree

public static boolean isClassTree(com.sun.source.tree.Tree tree)

Is the given tree kind a class, i.e. a class, enum, interface, or annotation type.

Parameters:

tree - the tree to test

Returns:

true, iff the given kind is a class kind

typeTreeKinds

public static java.util.Set<com.sun.source.tree.Tree.Kind> typeTreeKinds()

isTypeTree

public static boolean isTypeTree(com.sun.source.tree.Tree tree)

Is the given tree a type instantiation?

TODO: this is an under-approximation: e.g. an identifier could be either a type use or an expression. How can we distinguish.

Parameters:

tree - the tree to test

Returns:

true, iff the given tree is a type

isMethodInvocation

public static boolean isMethodInvocation(com.sun.source.tree.Tree tree,
                                         javax.lang.model.element.ExecutableElement method,
                                         javax.annotation.processing.ProcessingEnvironment env)

Returns true if the given element is an invocation of the method, or of any method that overrides that one.

getMethod

public static javax.lang.model.element.ExecutableElement getMethod(java.lang.String typeName,
                                                                   java.lang.String methodName,
                                                                   int params,
                                                                   javax.annotation.processing.ProcessingEnvironment env)

Returns the ExecutableElement for the method declaration of methodName, in class typeName, with params formal parameters. Errs if there is not exactly one matching method. If more than one method takes the same number of formal parameters, then use getMethod(String, String, ProcessingEnvironment, String...).

getMethodList

public static java.util.List<javax.lang.model.element.ExecutableElement> getMethodList(java.lang.String typeName,
                                                                                       java.lang.String methodName,
                                                                                       int params,
                                                                                       javax.annotation.processing.ProcessingEnvironment env)

Returns all ExecutableElements for method declarations of methodName, in class typeName, with params formal parameters.

getMethod

public static javax.lang.model.element.ExecutableElement getMethod(java.lang.String typeName,
                                                                   java.lang.String methodName,
                                                                   javax.annotation.processing.ProcessingEnvironment env,
                                                                   java.lang.String... paramTypes)

Returns the ExecutableElement for a method declaration of methodName, in class typeName, with formal parameters of the given types. Errs if there is no matching method.

isExplicitThisDereference

public static final boolean isExplicitThisDereference(com.sun.source.tree.ExpressionTree tree)

Determine whether the given expression is either "this" or an outer "C.this".

TODO: Should this also handle "super"?

isClassLiteral

public static boolean isClassLiteral(com.sun.source.tree.Tree tree)

Determine whether tree is a class literal, such as

   Object . class
 

Returns:

true iff if tree is a class literal

isFieldAccess

public static boolean isFieldAccess(com.sun.source.tree.Tree tree)

Determine whether tree is a field access expressions, such as

   f
   obj . f
 

Returns:

true iff if tree is a field access expression (implicit or explicit)

getFieldName

public static java.lang.String getFieldName(com.sun.source.tree.Tree tree)

Compute the name of the field that the field access tree accesses. Requires tree to be a field access, as determined by isFieldAccess.

Returns:

the name of the field accessed by tree.

isMethodAccess

public static boolean isMethodAccess(com.sun.source.tree.Tree tree)

Determine whether tree refers to a method element, such as

   m(...)
   obj . m(...)
 

Returns:

true iff if tree is a method access expression (implicit or explicit)

getMethodName

public static java.lang.String getMethodName(com.sun.source.tree.Tree tree)

Compute the name of the method that the method access tree accesses. Requires tree to be a method access, as determined by isMethodAccess.

Returns:

the name of the method accessed by tree.

canHaveTypeAnnotation

public static boolean canHaveTypeAnnotation(com.sun.source.tree.Tree tree)

Returns:

true if and only if tree can have a type annotation.

TODO: is this implementation precise enough? E.g. does a .class literal work correctly?

isSpecificFieldAccess

public static boolean isSpecificFieldAccess(com.sun.source.tree.Tree tree,
                                            javax.lang.model.element.VariableElement var)

Returns true if and only if the given tree represents a field access of the given VariableElement.

getField

public static javax.lang.model.element.VariableElement getField(java.lang.String typeName,
                                                                java.lang.String fieldName,
                                                                javax.annotation.processing.ProcessingEnvironment env)

Returns the VariableElement for a field declaration.

Parameters:

typeName - the class where the field is declared

fieldName - the name of the field

env - the processing environment

Returns:

the VariableElement for typeName.fieldName

isExpressionTree

public static boolean isExpressionTree(com.sun.source.tree.Tree tree)

Determine whether the given tree represents an ExpressionTree.

TODO: is there a nicer way than an instanceof?

Parameters:

tree - the Tree to test

Returns:

whether the tree is an ExpressionTree

isEnumSuper

public static boolean isEnumSuper(com.sun.source.tree.MethodInvocationTree node)

Parameters:

node - the method invocation to check

Returns:

true if this is a super call to the Enum constructor

isTypeDeclaration

public static boolean isTypeDeclaration(com.sun.source.tree.Tree node)

Determine whether the given tree represents a declaration of a type (including type parameters).

Parameters:

node - the Tree to test

Returns:

true if the tree is a type declaration

isGetClassInvocation

public static boolean isGetClassInvocation(com.sun.source.tree.MethodInvocationTree invocationTree)

Returns:

true iff invocationTree is an instance of getClass()

See Also:

Object.getClass()

isTreeInStaticScope

public static boolean isTreeInStaticScope(com.sun.source.util.TreePath path)

Returns whether or not the leaf of the tree path is in a static scope.

Parameters:

path - TreePath whose leaf may or may not be in static scope

Returns:

returns whether or not the leaf of the tree path is in a static scope

isArrayLengthAccess

public static boolean isArrayLengthAccess(com.sun.source.tree.Tree tree)

Returns whether or not tree is an access of array length.

Parameters:

tree - tree to check

Returns:

true if tree is an access of array length