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package org.checkerframework.dataflow.expression;
import com.sun.source.tree.ArrayAccessTree;
import com.sun.source.tree.BinaryTree;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.IdentifierTree;
import com.sun.source.tree.LiteralTree;
import com.sun.source.tree.MemberSelectTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.NewArrayTree;
import com.sun.source.tree.NewClassTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.UnaryTree;
import com.sun.source.tree.VariableTree;
import com.sun.source.util.TreePath;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.Name;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.type.TypeKind;
import javax.lang.model.type.TypeMirror;
import org.checkerframework.checker.interning.qual.EqualsMethod;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.checkerframework.dataflow.analysis.Store;
import org.checkerframework.dataflow.cfg.node.ArrayAccessNode;
import org.checkerframework.dataflow.cfg.node.ArrayCreationNode;
import org.checkerframework.dataflow.cfg.node.BinaryOperationNode;
import org.checkerframework.dataflow.cfg.node.ClassNameNode;
import org.checkerframework.dataflow.cfg.node.ExplicitThisNode;
import org.checkerframework.dataflow.cfg.node.FieldAccessNode;
import org.checkerframework.dataflow.cfg.node.LocalVariableNode;
import org.checkerframework.dataflow.cfg.node.MethodInvocationNode;
import org.checkerframework.dataflow.cfg.node.NarrowingConversionNode;
import org.checkerframework.dataflow.cfg.node.Node;
import org.checkerframework.dataflow.cfg.node.StringConversionNode;
import org.checkerframework.dataflow.cfg.node.SuperNode;
import org.checkerframework.dataflow.cfg.node.ThisNode;
import org.checkerframework.dataflow.cfg.node.UnaryOperationNode;
import org.checkerframework.dataflow.cfg.node.ValueLiteralNode;
import org.checkerframework.dataflow.cfg.node.WideningConversionNode;
import org.checkerframework.javacutil.AnnotationProvider;
import org.checkerframework.javacutil.BugInCF;
import org.checkerframework.javacutil.ElementUtils;
import org.checkerframework.javacutil.TreePathUtil;
import org.checkerframework.javacutil.TreeUtils;
import org.checkerframework.javacutil.TypesUtils;
import org.plumelib.util.CollectionsPlume;
// The Lock Checker also supports "" as a JavaExpression, but that is implemented in the Lock
// Checker.
// There are no special subclasses (AST nodes) for "".
/**
* This class represents a Java expression and its type. It does not represent all possible Java
* expressions (for example, it does not represent a ternary conditional expression {@code ?:}; use
* {@link org.checkerframework.dataflow.expression.Unknown} for unrepresentable expressions).
*
* This class's representation is like an AST: subparts are also expressions. For declared names
* (fields, local variables, and methods), it also contains an Element.
*
*
Each subclass represents a different type of expression, such as {@link
* org.checkerframework.dataflow.expression.MethodCall}, {@link
* org.checkerframework.dataflow.expression.ArrayAccess}, {@link
* org.checkerframework.dataflow.expression.LocalVariable}, etc.
*
* @see the syntax of
* Java expressions supported by the Checker Framework
*/
public abstract class JavaExpression {
/** The type of this expression. */
protected final TypeMirror type;
/**
* Create a JavaExpression.
*
* @param type the type of the expression
*/
protected JavaExpression(TypeMirror type) {
assert type != null;
this.type = type;
}
public TypeMirror getType() {
return type;
}
public abstract boolean containsOfClass(Class clazz);
public boolean containsUnknown() {
return containsOfClass(Unknown.class);
}
/**
* Returns true if the expression is deterministic.
*
* @param provider an annotation provider (a type factory)
* @return true if this expression is deterministic
*/
public abstract boolean isDeterministic(AnnotationProvider provider);
/**
* Returns true if all the expressions in the list are deterministic.
*
* @param list the list whose elements to test
* @param provider an annotation provider (a type factory)
* @return true if all the expressions in the list are deterministic
*/
public static boolean listIsDeterministic(
List list, AnnotationProvider provider) {
return list.stream().allMatch(je -> je == null || je.isDeterministic(provider));
}
/**
* Returns true if and only if the value this expression stands for cannot be changed (with
* respect to ==) by a method call. This is the case for local variables, the self reference,
* final field accesses whose receiver is {@link #isUnassignableByOtherCode}, and operations whose
* operands are all {@link #isUnmodifiableByOtherCode}.
*
* @see #isUnmodifiableByOtherCode
*/
public abstract boolean isUnassignableByOtherCode();
/**
* Returns true if and only if the value this expression stands for cannot be changed by a method
* call, including changes to any of its fields.
*
*
Approximately, this returns true if the expression is {@link #isUnassignableByOtherCode} and
* its type is immutable.
*
* @see #isUnassignableByOtherCode
*/
public abstract boolean isUnmodifiableByOtherCode();
/**
* Returns true if and only if the two Java expressions are syntactically identical.
*
*
This exists for use by {@link #containsSyntacticEqualJavaExpression}.
*
* @param je the other Java expression to compare to this one
* @return true if and only if the two Java expressions are syntactically identical
*/
@EqualsMethod
public abstract boolean syntacticEquals(JavaExpression je);
/**
* Returns true if the corresponding list elements satisfy {@link #syntacticEquals}.
*
* @param lst1 the first list to compare
* @param lst2 the second list to compare
* @return true if the corresponding list elements satisfy {@link #syntacticEquals}
*/
public static boolean syntacticEqualsList(
List lst1,
List lst2) {
if (lst1.size() != lst2.size()) {
return false;
}
for (int i = 0; i < lst1.size(); i++) {
JavaExpression dim1 = lst1.get(i);
JavaExpression dim2 = lst2.get(i);
if (dim1 == null && dim2 == null) {
continue;
} else if (dim1 == null || dim2 == null) {
return false;
} else {
if (!dim1.syntacticEquals(dim2)) {
return false;
}
}
}
return true;
}
/**
* Returns true if and only if this contains a JavaExpression that is syntactically equal to
* {@code other}.
*
* @param other the JavaExpression to search for
* @return true if and only if this contains a JavaExpression that is syntactically equal to
* {@code other}
*/
public abstract boolean containsSyntacticEqualJavaExpression(JavaExpression other);
/**
* Returns true if the given list contains a JavaExpression that is syntactically equal to {@code
* other}.
*
* @param list the list in which to search for a match
* @param other the JavaExpression to search for
* @return true if and only if the list contains a JavaExpression that is syntactically equal to
* {@code other}
*/
public static boolean listContainsSyntacticEqualJavaExpression(
List list, JavaExpression other) {
return list.stream()
.anyMatch(je -> je != null && je.containsSyntacticEqualJavaExpression(other));
}
/**
* Returns true if and only if {@code other} appears anywhere in this or an expression appears in
* this such that {@code other} might alias this expression, and that expression is modifiable.
*
*
This is always true, except for cases where the Java type information prevents aliasing and
* none of the subexpressions can alias 'other'.
*/
public boolean containsModifiableAliasOf(Store store, JavaExpression other) {
return this.equals(other) || store.canAlias(this, other);
}
/**
* Format this verbosely, for debugging.
*
* @return a verbose string representation of this
*/
public String toStringDebug() {
return String.format("%s(%s): %s", getClass().getSimpleName(), type, toString());
}
///
/// Static methods
///
/**
* Returns the Java expression for a {@link FieldAccessNode}. The result may contain {@link
* Unknown} as receiver.
*
* @param node the FieldAccessNode to convert to a JavaExpression
* @return the {@link FieldAccess} or {@link ClassName} that corresponds to {@code node}
*/
public static JavaExpression fromNodeFieldAccess(FieldAccessNode node) {
Node receiverNode = node.getReceiver();
String fieldName = node.getFieldName();
if (fieldName.equals("this")) {
// The CFG represents "className.this" as a FieldAccessNode, but it isn't a field
// access.
return new ThisReference(receiverNode.getType());
} else if (fieldName.equals("class")) {
// The CFG represents "className.class" as a FieldAccessNode; bit it is a class literal.
return new ClassName(receiverNode.getType());
}
JavaExpression receiver;
if (node.isStatic()) {
receiver = new ClassName(receiverNode.getType());
} else {
receiver = fromNode(receiverNode);
}
return new FieldAccess(receiver, node);
}
/**
* Returns the internal representation (as {@link FieldAccess}) of a {@link FieldAccessNode}. The
* result may contain {@link Unknown} as receiver.
*
* @param node the ArrayAccessNode to convert to a JavaExpression
* @return the internal representation (as {@link FieldAccess}) of a {@link FieldAccessNode}. Can
* contain {@link Unknown} as receiver.
*/
public static ArrayAccess fromArrayAccess(ArrayAccessNode node) {
JavaExpression array = fromNode(node.getArray());
JavaExpression index = fromNode(node.getIndex());
return new ArrayAccess(node.getType(), array, index);
}
/**
* We ignore operations such as widening and narrowing when computing the internal representation.
*
* @param receiverNode a node to convert to a JavaExpression
* @return the internal representation of the given node. Might contain {@link Unknown}.
*/
public static JavaExpression fromNode(Node receiverNode) {
JavaExpression result = null;
if (receiverNode instanceof FieldAccessNode) {
result = fromNodeFieldAccess((FieldAccessNode) receiverNode);
} else if (receiverNode instanceof ExplicitThisNode) {
result = new ThisReference(receiverNode.getType());
} else if (receiverNode instanceof ThisNode) {
result = new ThisReference(receiverNode.getType());
} else if (receiverNode instanceof SuperNode) {
result = new ThisReference(receiverNode.getType());
} else if (receiverNode instanceof LocalVariableNode) {
LocalVariableNode lv = (LocalVariableNode) receiverNode;
result = new LocalVariable(lv);
} else if (receiverNode instanceof ArrayAccessNode) {
ArrayAccessNode a = (ArrayAccessNode) receiverNode;
result = fromArrayAccess(a);
} else if (receiverNode instanceof StringConversionNode) {
// ignore string conversion
return fromNode(((StringConversionNode) receiverNode).getOperand());
} else if (receiverNode instanceof WideningConversionNode) {
// ignore widening
return fromNode(((WideningConversionNode) receiverNode).getOperand());
} else if (receiverNode instanceof NarrowingConversionNode) {
// ignore narrowing
return fromNode(((NarrowingConversionNode) receiverNode).getOperand());
} else if (receiverNode instanceof UnaryOperationNode) {
UnaryOperationNode uopn = (UnaryOperationNode) receiverNode;
return new UnaryOperation(uopn, fromNode(uopn.getOperand()));
} else if (receiverNode instanceof BinaryOperationNode) {
BinaryOperationNode bopn = (BinaryOperationNode) receiverNode;
return new BinaryOperation(
bopn, fromNode(bopn.getLeftOperand()), fromNode(bopn.getRightOperand()));
} else if (receiverNode instanceof ClassNameNode) {
ClassNameNode cn = (ClassNameNode) receiverNode;
result = new ClassName(cn.getType());
} else if (receiverNode instanceof ValueLiteralNode) {
ValueLiteralNode vn = (ValueLiteralNode) receiverNode;
result = new ValueLiteral(vn.getType(), vn);
} else if (receiverNode instanceof ArrayCreationNode) {
ArrayCreationNode an = (ArrayCreationNode) receiverNode;
List<@Nullable JavaExpression> dimensions =
CollectionsPlume.mapList(JavaExpression::fromNode, an.getDimensions());
List initializers =
CollectionsPlume.mapList(JavaExpression::fromNode, an.getInitializers());
result = new ArrayCreation(an.getType(), dimensions, initializers);
} else if (receiverNode instanceof MethodInvocationNode) {
MethodInvocationNode mn = (MethodInvocationNode) receiverNode;
MethodInvocationTree t = mn.getTree();
if (t == null) {
throw new BugInCF("Unexpected null tree for node: " + mn);
}
assert TreeUtils.isUseOfElement(t) : "@AssumeAssertion(nullness): tree kind";
ExecutableElement invokedMethod = TreeUtils.elementFromUse(t);
// Note that the method might be nondeterministic.
List parameters =
CollectionsPlume.mapList(JavaExpression::fromNode, mn.getArguments());
JavaExpression methodReceiver;
if (ElementUtils.isStatic(invokedMethod)) {
methodReceiver = new ClassName(mn.getTarget().getReceiver().getType());
} else {
methodReceiver = fromNode(mn.getTarget().getReceiver());
}
result = new MethodCall(mn.getType(), invokedMethod, methodReceiver, parameters);
}
if (result == null) {
result = new Unknown(receiverNode);
}
return result;
}
/**
* Converts a javac {@link ExpressionTree} to a CF JavaExpression. The result might contain {@link
* Unknown}.
*
* We ignore operations such as widening and narrowing when computing the JavaExpression.
*
* @param tree a javac tree
* @return a JavaExpression for the given javac tree
*/
public static JavaExpression fromTree(ExpressionTree tree) {
JavaExpression result;
switch (tree.getKind()) {
case ARRAY_ACCESS:
ArrayAccessTree a = (ArrayAccessTree) tree;
JavaExpression arrayAccessExpression = fromTree(a.getExpression());
JavaExpression index = fromTree(a.getIndex());
result = new ArrayAccess(TreeUtils.typeOf(a), arrayAccessExpression, index);
break;
case BOOLEAN_LITERAL:
case CHAR_LITERAL:
case DOUBLE_LITERAL:
case FLOAT_LITERAL:
case INT_LITERAL:
case LONG_LITERAL:
case NULL_LITERAL:
case STRING_LITERAL:
LiteralTree vn = (LiteralTree) tree;
result = new ValueLiteral(TreeUtils.typeOf(tree), vn.getValue());
break;
case NEW_ARRAY:
NewArrayTree newArrayTree = (NewArrayTree) tree;
List<@Nullable JavaExpression> dimensions;
if (newArrayTree.getDimensions() == null) {
dimensions = Collections.emptyList();
} else {
dimensions = new ArrayList<>(newArrayTree.getDimensions().size());
for (ExpressionTree dimension : newArrayTree.getDimensions()) {
dimensions.add(fromTree(dimension));
}
}
List initializers;
if (newArrayTree.getInitializers() == null) {
initializers = Collections.emptyList();
} else {
initializers = new ArrayList<>(newArrayTree.getInitializers().size());
for (ExpressionTree initializer : newArrayTree.getInitializers()) {
initializers.add(fromTree(initializer));
}
}
result = new ArrayCreation(TreeUtils.typeOf(tree), dimensions, initializers);
break;
case METHOD_INVOCATION:
MethodInvocationTree mn = (MethodInvocationTree) tree;
assert TreeUtils.isUseOfElement(mn) : "@AssumeAssertion(nullness): tree kind";
ExecutableElement invokedMethod = TreeUtils.elementFromUse(mn);
// Note that the method might be nondeterministic.
List parameters =
CollectionsPlume.mapList(JavaExpression::fromTree, mn.getArguments());
JavaExpression methodReceiver;
if (ElementUtils.isStatic(invokedMethod)) {
@SuppressWarnings(
"nullness:assignment" // enclosingTypeElement(ExecutableElement): @NonNull
)
@NonNull TypeElement methodType = ElementUtils.enclosingTypeElement(invokedMethod);
methodReceiver = new ClassName(methodType.asType());
} else {
methodReceiver = getReceiver(mn);
}
TypeMirror resultType = TreeUtils.typeOf(mn);
result = new MethodCall(resultType, invokedMethod, methodReceiver, parameters);
break;
case MEMBER_SELECT:
result = fromMemberSelect((MemberSelectTree) tree);
break;
case IDENTIFIER:
IdentifierTree identifierTree = (IdentifierTree) tree;
TypeMirror typeOfId = TreeUtils.typeOf(identifierTree);
Name identifierName = identifierTree.getName();
if (identifierName.contentEquals("this") || identifierName.contentEquals("super")) {
result = new ThisReference(typeOfId);
break;
}
assert TreeUtils.isUseOfElement(identifierTree) : "@AssumeAssertion(nullness): tree kind";
Element ele = TreeUtils.elementFromUse(identifierTree);
if (ele == null) {
result = null;
} else if (ElementUtils.isTypeElement(ele)) {
result = new ClassName(ele.asType());
} else {
result = fromVariableElement(typeOfId, (VariableElement) ele, identifierTree);
}
break;
case UNARY_PLUS:
return fromTree(((UnaryTree) tree).getExpression());
case BITWISE_COMPLEMENT:
case LOGICAL_COMPLEMENT:
case POSTFIX_DECREMENT:
case POSTFIX_INCREMENT:
case PREFIX_DECREMENT:
case PREFIX_INCREMENT:
case UNARY_MINUS:
JavaExpression operand = fromTree(((UnaryTree) tree).getExpression());
return new UnaryOperation(TreeUtils.typeOf(tree), tree.getKind(), operand);
case CONDITIONAL_AND:
case CONDITIONAL_OR:
case DIVIDE:
case EQUAL_TO:
case GREATER_THAN:
case GREATER_THAN_EQUAL:
case LEFT_SHIFT:
case LESS_THAN:
case LESS_THAN_EQUAL:
case MINUS:
case MULTIPLY:
case NOT_EQUAL_TO:
case OR:
case PLUS:
case REMAINDER:
case RIGHT_SHIFT:
case UNSIGNED_RIGHT_SHIFT:
case XOR:
BinaryTree binaryTree = (BinaryTree) tree;
JavaExpression left = fromTree(binaryTree.getLeftOperand());
JavaExpression right = fromTree(binaryTree.getRightOperand());
return new BinaryOperation(TreeUtils.typeOf(tree), tree.getKind(), left, right);
default:
result = null;
}
if (result == null) {
result = new Unknown(tree);
}
return result;
}
/**
* Returns the Java expression corresponding to the given variable tree {@code tree}.
*
* @param tree a variable tree
* @return a JavaExpression for {@code tree}
*/
public static JavaExpression fromVariableTree(VariableTree tree) {
return fromVariableElement(
TreeUtils.typeOf(tree), TreeUtils.elementFromDeclaration(tree), tree);
}
/**
* Returns the Java expression corresponding to the given variable element {@code ele}.
*
* @param typeOfEle the type of {@code ele}
* @param ele element whose JavaExpression is returned
* @param tree the tree for the variable
* @return the Java expression corresponding to the given variable element {@code ele}
*/
private static JavaExpression fromVariableElement(
TypeMirror typeOfEle, @Nullable VariableElement ele, Tree tree) {
if (ele == null) {
return new Unknown(tree);
}
switch (ele.getKind()) {
case LOCAL_VARIABLE:
case RESOURCE_VARIABLE:
case EXCEPTION_PARAMETER:
case PARAMETER:
return new LocalVariable(ele);
case FIELD:
case ENUM_CONSTANT:
// Implicit access expression, such as "this" or a class name
JavaExpression fieldAccessExpression;
@SuppressWarnings("nullness:dereference.of.nullable") // a field has enclosing class
TypeMirror enclosingTypeElement = ElementUtils.enclosingTypeElement(ele).asType();
if (ElementUtils.isStatic(ele)) {
fieldAccessExpression = new ClassName(enclosingTypeElement);
} else {
fieldAccessExpression = new ThisReference(enclosingTypeElement);
}
return new FieldAccess(fieldAccessExpression, typeOfEle, ele);
default:
if (ElementUtils.isBindingVariable(ele)) {
return new LocalVariable(ele);
}
throw new BugInCF(
"Unexpected kind of VariableTree: kind: %s element: %s", ele.getKind(), ele);
}
}
/**
* Creates a JavaExpression from the {@code memberSelectTree}.
*
* @param memberSelectTree tree
* @return a JavaExpression for {@code memberSelectTree}
*/
private static JavaExpression fromMemberSelect(MemberSelectTree memberSelectTree) {
TypeMirror expressionType = TreeUtils.typeOf(memberSelectTree.getExpression());
if (TreeUtils.isClassLiteral(memberSelectTree)) {
// the identifier is "class"
return new ClassName(expressionType);
}
if (TreeUtils.isExplicitThisDereference(memberSelectTree)) {
// the identifier is "class"
return new ThisReference(expressionType);
}
assert TreeUtils.isUseOfElement(memberSelectTree) : "@AssumeAssertion(nullness): tree kind";
Element ele = TreeUtils.elementFromUse(memberSelectTree);
if (ElementUtils.isTypeElement(ele)) {
// o instanceof MyClass.InnerClass
// o instanceof MyClass.InnerInterface
TypeMirror selectType = TreeUtils.typeOf(memberSelectTree);
return new ClassName(selectType);
}
switch (ele.getKind()) {
case METHOD:
case CONSTRUCTOR:
return fromTree(memberSelectTree.getExpression());
case ENUM_CONSTANT:
case FIELD:
TypeMirror fieldType = TreeUtils.typeOf(memberSelectTree);
JavaExpression je = fromTree(memberSelectTree.getExpression());
return new FieldAccess(je, fieldType, (VariableElement) ele);
default:
throw new BugInCF("Unexpected element kind: %s element: %s", ele.getKind(), ele);
}
}
/**
* Returns the parameters of {@code methodEle} as {@link LocalVariable}s.
*
* @param methodEle the method element
* @return list of parameters as {@link LocalVariable}s
*/
public static List getParametersAsLocalVariables(ExecutableElement methodEle) {
return CollectionsPlume.mapList(LocalVariable::new, methodEle.getParameters());
}
/**
* Returns the parameters of {@code methodEle} as {@link FormalParameter}s.
*
* @param methodEle the method element
* @return list of parameters as {@link FormalParameter}s
*/
public static List getFormalParameters(ExecutableElement methodEle) {
List parameters = new ArrayList<>(methodEle.getParameters().size());
int oneBasedIndex = 1;
for (VariableElement variableElement : methodEle.getParameters()) {
parameters.add(new FormalParameter(oneBasedIndex, variableElement));
oneBasedIndex++;
}
return parameters;
}
///
/// Obtaining the receiver
///
/**
* Returns the receiver of the given invocation.
*
* @param accessTree a method or constructor invocation
* @return the receiver of the given invocation
*/
public static JavaExpression getReceiver(ExpressionTree accessTree) {
// TODO: Handle field accesses too?
assert accessTree instanceof MethodInvocationTree || accessTree instanceof NewClassTree;
ExpressionTree receiverTree = TreeUtils.getReceiverTree(accessTree);
if (receiverTree != null) {
return fromTree(receiverTree);
} else {
Element ele = TreeUtils.elementFromUse(accessTree);
if (ele == null) {
throw new BugInCF("TreeUtils.elementFromUse(" + accessTree + ") => null");
}
return getImplicitReceiver(ele);
}
}
/**
* Returns the implicit receiver of ele.
*
* Returns either a new ClassName or a new ThisReference depending on whether ele is static or
* not. The passed element must be a field, method, or class.
*
*
When this returns a ThisReference, its type is the class that declares {@code ele}, which is
* not necessarily the type of {@code this} at the invocation site.
*
* @param ele a field, method, or class
* @return either a new ClassName or a new ThisReference depending on whether ele is static or not
*/
public static JavaExpression getImplicitReceiver(Element ele) {
TypeElement enclosingTypeElement = ElementUtils.enclosingTypeElement(ele);
if (enclosingTypeElement == null) {
throw new BugInCF("getImplicitReceiver's arg has no enclosing type: " + ele);
}
TypeMirror enclosingType = enclosingTypeElement.asType();
if (ElementUtils.isStatic(ele)) {
return new ClassName(enclosingType);
} else {
return new ThisReference(enclosingType);
}
}
/**
* Returns either a new ClassName or ThisReference JavaExpression object for the enclosingType.
*
*
The Tree should be an expression or a statement that does not have a receiver or an implicit
* receiver. For example, a local variable declaration.
*
* @param path a tree path
* @param enclosingType type of the enclosing type
* @return a new {@link ClassName} or {@link ThisReference} that is a JavaExpression object for
* the enclosingType
*/
public static JavaExpression getPseudoReceiver(TreePath path, TypeMirror enclosingType) {
if (TreePathUtil.isTreeInStaticScope(path)) {
return new ClassName(enclosingType);
} else {
return new ThisReference(enclosingType);
}
}
/**
* Accept method of the visitor pattern.
*
* @param visitor the visitor to be applied to this JavaExpression
* @param p the parameter for this operation
* @param result type of the operation
* @param parameter type
* @return the result of visiting this
*/
public abstract R accept(JavaExpressionVisitor visitor, P p);
/**
* Viewpoint-adapts {@code this} to a field access with receiver {@code receiver}.
*
* @param receiver receiver of the field access
* @return viewpoint-adapted version of this
*/
public JavaExpression atFieldAccess(JavaExpression receiver) {
return ViewpointAdaptJavaExpression.viewpointAdapt(this, receiver);
}
/**
* Viewpoint-adapts {@code this} to the {@code methodTree} by converting any {@code
* FormalParameter} into {@code LocalVariable}s.
*
* @param methodTree method declaration tree
* @return viewpoint-adapted version of this
*/
public final JavaExpression atMethodBody(MethodTree methodTree) {
@SuppressWarnings("nullness:argument") // elementFromDeclaration is non-null for a parameter
List parametersJe =
CollectionsPlume.mapList(
(VariableTree param) -> new LocalVariable(TreeUtils.elementFromDeclaration(param)),
methodTree.getParameters());
return ViewpointAdaptJavaExpression.viewpointAdapt(this, parametersJe);
}
/**
* Viewpoint-adapts {@code this} to the {@code methodInvocationTree}.
*
* @param methodInvocationTree method invocation
* @return viewpoint-adapted version of this
*/
public final JavaExpression atMethodInvocation(MethodInvocationTree methodInvocationTree) {
JavaExpression receiverJe = JavaExpression.getReceiver(methodInvocationTree);
List argumentsJe =
argumentTreesToJavaExpressions(
TreeUtils.elementFromUse(methodInvocationTree), methodInvocationTree.getArguments());
return ViewpointAdaptJavaExpression.viewpointAdapt(this, receiverJe, argumentsJe);
}
/**
* Viewpoint-adapts {@code this} to the {@code invocationNode}.
*
* @param invocationNode method invocation
* @return viewpoint-adapted version of this
*/
public final JavaExpression atMethodInvocation(MethodInvocationNode invocationNode) {
JavaExpression receiverJe = JavaExpression.fromNode(invocationNode.getTarget().getReceiver());
List argumentsJe =
CollectionsPlume.mapList(JavaExpression::fromNode, invocationNode.getArguments());
return ViewpointAdaptJavaExpression.viewpointAdapt(this, receiverJe, argumentsJe);
}
/**
* Viewpoint-adapts {@code this} to the {@code newClassTree}.
*
* @param newClassTree constructor invocation
* @return viewpoint-adapted version of this
*/
public JavaExpression atConstructorInvocation(NewClassTree newClassTree) {
JavaExpression receiverJe = JavaExpression.getReceiver(newClassTree);
List argumentsJe =
argumentTreesToJavaExpressions(
TreeUtils.elementFromUse(newClassTree), newClassTree.getArguments());
return ViewpointAdaptJavaExpression.viewpointAdapt(this, receiverJe, argumentsJe);
}
/**
* Converts method or constructor arguments from Trees to JavaExpressions, accounting for varargs.
*
* @param method the method or constructor being invoked
* @param argTrees the arguments to the method or constructor
* @return the arguments, as JavaExpressions
*/
private static List argumentTreesToJavaExpressions(
ExecutableElement method, List argTrees) {
if (isVarArgsInvocation(method, argTrees)) {
List result = new ArrayList<>(method.getParameters().size());
for (int i = 0; i < method.getParameters().size() - 1; i++) {
result.add(JavaExpression.fromTree(argTrees.get(i)));
}
List varargArgs =
new ArrayList<>(argTrees.size() - method.getParameters().size() + 1);
for (int i = method.getParameters().size() - 1; i < argTrees.size(); i++) {
varargArgs.add(JavaExpression.fromTree(argTrees.get(i)));
}
Element varargsElement = method.getParameters().get(method.getParameters().size() - 1);
TypeMirror tm = ElementUtils.getType(varargsElement);
result.add(new ArrayCreation(tm, Collections.emptyList(), varargArgs));
return result;
}
return CollectionsPlume.mapList(JavaExpression::fromTree, argTrees);
}
/**
* Returns true if method is a varargs method or constructor and its varargs arguments are not
* passed in an array.
*
* @param method the method or constructor
* @param args the arguments at the call site
* @return true if method is a varargs method and its varargs arguments are not passed in an array
*/
private static boolean isVarArgsInvocation(
ExecutableElement method, List args) {
if (!method.isVarArgs()) {
return false;
}
if (method.getParameters().size() != args.size()) {
return true;
}
TypeMirror lastArgType = TreeUtils.typeOf(args.get(args.size() - 1));
if (lastArgType.getKind() != TypeKind.ARRAY) {
return true;
}
List paramElts = method.getParameters();
VariableElement lastParamElt = paramElts.get(paramElts.size() - 1);
return TypesUtils.getArrayDepth(ElementUtils.getType(lastParamElt))
!= TypesUtils.getArrayDepth(lastArgType);
}
}