org.checkerframework.framework.flow.CFAbstractTransfer Maven / Gradle / Ivy
package org.checkerframework.framework.flow;
import com.sun.source.tree.ClassTree;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.NewClassTree;
import com.sun.source.tree.Tree;
import com.sun.source.util.TreePath;
import org.checkerframework.checker.interning.qual.InternedDistinct;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.checkerframework.checker.nullness.qual.PolyNull;
import org.checkerframework.dataflow.analysis.ConditionalTransferResult;
import org.checkerframework.dataflow.analysis.ForwardTransferFunction;
import org.checkerframework.dataflow.analysis.RegularTransferResult;
import org.checkerframework.dataflow.analysis.TransferInput;
import org.checkerframework.dataflow.analysis.TransferResult;
import org.checkerframework.dataflow.cfg.UnderlyingAST;
import org.checkerframework.dataflow.cfg.UnderlyingAST.CFGLambda;
import org.checkerframework.dataflow.cfg.UnderlyingAST.CFGMethod;
import org.checkerframework.dataflow.cfg.node.AbstractNodeVisitor;
import org.checkerframework.dataflow.cfg.node.ArrayAccessNode;
import org.checkerframework.dataflow.cfg.node.AssignmentNode;
import org.checkerframework.dataflow.cfg.node.CaseNode;
import org.checkerframework.dataflow.cfg.node.ClassNameNode;
import org.checkerframework.dataflow.cfg.node.ConditionalNotNode;
import org.checkerframework.dataflow.cfg.node.DeconstructorPatternNode;
import org.checkerframework.dataflow.cfg.node.EqualToNode;
import org.checkerframework.dataflow.cfg.node.ExpressionStatementNode;
import org.checkerframework.dataflow.cfg.node.FieldAccessNode;
import org.checkerframework.dataflow.cfg.node.InstanceOfNode;
import org.checkerframework.dataflow.cfg.node.LambdaResultExpressionNode;
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.NotEqualNode;
import org.checkerframework.dataflow.cfg.node.ObjectCreationNode;
import org.checkerframework.dataflow.cfg.node.ReturnNode;
import org.checkerframework.dataflow.cfg.node.StringConversionNode;
import org.checkerframework.dataflow.cfg.node.SwitchExpressionNode;
import org.checkerframework.dataflow.cfg.node.TernaryExpressionNode;
import org.checkerframework.dataflow.cfg.node.ThisNode;
import org.checkerframework.dataflow.cfg.node.VariableDeclarationNode;
import org.checkerframework.dataflow.cfg.node.WideningConversionNode;
import org.checkerframework.dataflow.expression.FieldAccess;
import org.checkerframework.dataflow.expression.JavaExpression;
import org.checkerframework.dataflow.expression.LocalVariable;
import org.checkerframework.dataflow.qual.Pure;
import org.checkerframework.dataflow.qual.SideEffectFree;
import org.checkerframework.dataflow.util.NodeUtils;
import org.checkerframework.framework.flow.CFAbstractAnalysis.FieldInitialValue;
import org.checkerframework.framework.type.AnnotatedTypeFactory;
import org.checkerframework.framework.type.AnnotatedTypeMirror;
import org.checkerframework.framework.type.GenericAnnotatedTypeFactory;
import org.checkerframework.framework.util.Contract;
import org.checkerframework.framework.util.Contract.ConditionalPostcondition;
import org.checkerframework.framework.util.Contract.Postcondition;
import org.checkerframework.framework.util.Contract.Precondition;
import org.checkerframework.framework.util.ContractsFromMethod;
import org.checkerframework.framework.util.JavaExpressionParseUtil.JavaExpressionParseException;
import org.checkerframework.framework.util.StringToJavaExpression;
import org.checkerframework.javacutil.AnnotationMirrorSet;
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 java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.Element;
import javax.lang.model.element.ElementKind;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.type.TypeMirror;
/**
* The default analysis transfer function for the Checker Framework. It propagates information
* through assignments. It uses the {@link AnnotatedTypeFactory} to provide checker-specific logic
* to combine types (e.g., what is the type of a string concatenation, given the types of the two
* operands) and acts as an abstraction function (e.g., determine the annotations on literals).
*
* Design note: CFAbstractTransfer and its subclasses are supposed to act as transfer functions.
* But, since the AnnotatedTypeFactory already existed and performed checker-independent type
* propagation, CFAbstractTransfer delegates work to it instead of duplicating some logic in
* CFAbstractTransfer. The checker-specific subclasses of CFAbstractTransfer do implement transfer
* function logic themselves.
*/
public abstract class CFAbstractTransfer<
V extends CFAbstractValue,
S extends CFAbstractStore,
T extends CFAbstractTransfer>
extends AbstractNodeVisitor, TransferInput>
implements ForwardTransferFunction {
/** The analysis used by this transfer function. */
protected final CFAbstractAnalysis analysis;
/**
* Should the analysis use sequential Java semantics (i.e., assume that only one thread is
* running at all times)?
*/
protected final boolean sequentialSemantics;
/* NO-AFU Indicates that the whole-program inference is on. */
/* NO-AFU
private final boolean infer;
*/
/**
* Create a CFAbstractTransfer.
*
* @param analysis the analysis used by this transfer function
*/
protected CFAbstractTransfer(CFAbstractAnalysis analysis) {
this(analysis, false);
}
/**
* Constructor that allows forcing concurrent semantics to be on for this instance of
* CFAbstractTransfer.
*
* @param analysis the analysis used by this transfer function
* @param forceConcurrentSemantics whether concurrent semantics should be forced to be on. If
* false, concurrent semantics are turned off by default, but the user can still turn them
* on via {@code -AconcurrentSemantics}. If true, the user cannot turn off concurrent
* semantics.
*/
protected CFAbstractTransfer(
CFAbstractAnalysis analysis, boolean forceConcurrentSemantics) {
this.analysis = analysis;
this.sequentialSemantics =
!(forceConcurrentSemantics || analysis.checker.hasOption("concurrentSemantics"));
/* NO-AFU
this.infer = analysis.checker.hasOption("infer");
*/
}
/**
* Returns true if the transfer function uses sequential semantics, false if it uses concurrent
* semantics. Useful when creating an empty store, since a store makes different decisions
* depending on whether sequential or concurrent semantics are used.
*
* @return true if the transfer function uses sequential semantics, false if it uses concurrent
* semantics
*/
@Pure
public boolean usesSequentialSemantics() {
return sequentialSemantics;
}
/**
* A hook for subclasses to modify the result of the transfer function. This method is called
* before returning the abstract value {@code value} as the result of the transfer function.
*
* If a subclass overrides this method, the subclass should also override {@link
* #finishValue(CFAbstractValue,CFAbstractStore,CFAbstractStore)}.
*
* @param value a value to possibly modify
* @param store the store
* @return the possibly-modified value
*/
@SideEffectFree
protected @Nullable V finishValue(@Nullable V value, S store) {
return value;
}
/**
* A hook for subclasses to modify the result of the transfer function. This method is called
* before returning the abstract value {@code value} as the result of the transfer function.
*
*
If a subclass overrides this method, the subclass should also override {@link
* #finishValue(CFAbstractValue,CFAbstractStore)}.
*
* @param value the value to finish
* @param thenStore the "then" store
* @param elseStore the "else" store
* @return the possibly-modified value
*/
@SideEffectFree
protected @Nullable V finishValue(@Nullable V value, S thenStore, S elseStore) {
return value;
}
/**
* Returns the abstract value of a non-leaf tree {@code tree}, as computed by the {@link
* AnnotatedTypeFactory}.
*
* @return the abstract value of a non-leaf tree {@code tree}, as computed by the {@link
* AnnotatedTypeFactory}
*/
protected V getValueFromFactory(Tree tree, Node node) {
GenericAnnotatedTypeFactory> factory =
analysis.atypeFactory;
Tree preTree = analysis.getCurrentTree();
analysis.setCurrentTree(tree);
AnnotatedTypeMirror at;
if (node instanceof MethodInvocationNode
&& ((MethodInvocationNode) node).getIterableExpression() != null) {
ExpressionTree iter = ((MethodInvocationNode) node).getIterableExpression();
at = factory.getIterableElementType(iter);
} else if (node instanceof ArrayAccessNode
&& ((ArrayAccessNode) node).getArrayExpression() != null) {
ExpressionTree array = ((ArrayAccessNode) node).getArrayExpression();
at = factory.getIterableElementType(array);
} else {
at = factory.getAnnotatedType(tree);
}
analysis.setCurrentTree(preTree);
return analysis.createAbstractValue(at);
}
/** The fixed initial store. */
private @Nullable S fixedInitialStore = null;
/**
* Set a fixed initial Store.
*
* @param s initial store; possible null
*/
public void setFixedInitialStore(@Nullable S s) {
fixedInitialStore = s;
}
/** The initial store maps method formal parameters to their currently most refined type. */
@Override
public S initialStore(UnderlyingAST underlyingAST, List parameters) {
if (underlyingAST.getKind() != UnderlyingAST.Kind.LAMBDA
&& underlyingAST.getKind() != UnderlyingAST.Kind.METHOD) {
if (fixedInitialStore != null) {
return fixedInitialStore;
} else {
return analysis.createEmptyStore(sequentialSemantics);
}
}
S store;
AnnotatedTypeFactory atypeFactory = analysis.getTypeFactory();
if (underlyingAST.getKind() == UnderlyingAST.Kind.METHOD) {
if (fixedInitialStore != null) {
// copy knowledge
store = analysis.createCopiedStore(fixedInitialStore);
} else {
store = analysis.createEmptyStore(sequentialSemantics);
}
for (LocalVariableNode p : parameters) {
AnnotatedTypeMirror anno = atypeFactory.getAnnotatedType(p.getElement());
store.initializeMethodParameter(p, analysis.createAbstractValue(anno));
}
// add properties known through precondition
CFGMethod method = (CFGMethod) underlyingAST;
MethodTree methodDeclTree = method.getMethod();
ExecutableElement methodElem = TreeUtils.elementFromDeclaration(methodDeclTree);
addInformationFromPreconditions(
store, atypeFactory, method, methodDeclTree, methodElem);
addInitialFieldValues(store, method.getClassTree(), methodDeclTree);
addFinalLocalValues(store, methodElem);
/* NO-AFU
if (shouldPerformWholeProgramInference(methodDeclTree, methodElem)) {
Map overriddenMethods =
AnnotatedTypes.overriddenMethods(
atypeFactory.getElementUtils(), atypeFactory, methodElem);
for (Map.Entry pair :
overriddenMethods.entrySet()) {
AnnotatedExecutableType overriddenMethod =
AnnotatedTypes.asMemberOf(
atypeFactory.getProcessingEnv().getTypeUtils(),
atypeFactory,
pair.getKey(),
pair.getValue());
// Infers parameter and receiver types of the method based
// on the overridden method.
atypeFactory
.getWholeProgramInference()
.updateFromOverride(methodDeclTree, methodElem, overriddenMethod);
}
}
*/
} else if (underlyingAST.getKind() == UnderlyingAST.Kind.LAMBDA) {
if (fixedInitialStore != null) {
// Create a copy and keep only the field values (nothing else applies).
store = analysis.createCopiedStore(fixedInitialStore);
// Allow that local variables are retained; they are effectively final,
// otherwise Java wouldn't allow access from within the lambda.
// TODO: what about the other information? Can code further down be simplified?
// store.localVariableValues.clear();
store.classValues.clear();
store.arrayValues.clear();
store.methodValues.clear();
} else {
store = analysis.createEmptyStore(sequentialSemantics);
}
for (LocalVariableNode p : parameters) {
AnnotatedTypeMirror anno = atypeFactory.getAnnotatedType(p.getElement());
store.initializeMethodParameter(p, analysis.createAbstractValue(anno));
}
CFGLambda lambda = (CFGLambda) underlyingAST;
@SuppressWarnings("interning:assignment.type.incompatible") // used in == tests
@InternedDistinct Tree enclosingTree =
TreePathUtil.enclosingOfKind(
atypeFactory.getPath(lambda.getLambdaTree()),
TreeUtils.classAndMethodTreeKinds());
Element enclosingElement = null;
if (enclosingTree.getKind() == Tree.Kind.METHOD) {
// If it is in an initializer, we need to use locals from the initializer.
enclosingElement = TreeUtils.elementFromDeclaration((MethodTree) enclosingTree);
} else if (TreeUtils.isClassTree(enclosingTree)) {
// Try to find an enclosing initializer block.
// Would love to know if there was a better way.
// Find any enclosing element of the lambda (using trees).
// Then go up the elements to find an initializer element (which can't be found with
// the tree).
TreePath loopTree = atypeFactory.getPath(lambda.getLambdaTree()).getParentPath();
Element anEnclosingElement = null;
while (loopTree.getLeaf() != enclosingTree) {
Element sym = TreeUtils.elementFromTree(loopTree.getLeaf());
if (sym != null) {
anEnclosingElement = sym;
break;
}
loopTree = loopTree.getParentPath();
}
while (anEnclosingElement != null
&& !anEnclosingElement.equals(TreeUtils.elementFromTree(enclosingTree))) {
if (anEnclosingElement.getKind() == ElementKind.INSTANCE_INIT
|| anEnclosingElement.getKind() == ElementKind.STATIC_INIT) {
enclosingElement = anEnclosingElement;
break;
}
anEnclosingElement = anEnclosingElement.getEnclosingElement();
}
}
if (enclosingElement != null) {
addFinalLocalValues(store, enclosingElement);
}
// We want the initialization stuff, but need to throw out any refinements.
Map fieldValuesClone = new HashMap<>(store.fieldValues);
for (Map.Entry fieldValue : fieldValuesClone.entrySet()) {
AnnotatedTypeMirror declaredType =
atypeFactory.getAnnotatedType(fieldValue.getKey().getField());
V lubbedValue =
analysis.createAbstractValue(declaredType)
.leastUpperBound(fieldValue.getValue());
store.fieldValues.put(fieldValue.getKey(), lubbedValue);
}
} else {
assert false : "Unexpected tree: " + underlyingAST;
store = null;
}
return store;
}
/**
* Add field values to the initial store before {@code methodTree}.
*
* The initializer value is inserted into {@code store} if the field is final and the field
* type is immutable, as defined by {@link AnnotatedTypeFactory#isImmutable(TypeMirror)}.
*
*
The declared value is inserted into {@code store} if:
*
*
* - {@code methodTree} is a constructor and the field has an initializer. (Use the
* declaration type rather than the initializer because an initialization block might have
* re-set it.)
*
- {@code methodTree} is not a constructor and the receiver is fully initialized as
* determined by {@link #isNotFullyInitializedReceiver(MethodTree)}.
*
*
* @param store initial store into which field values are inserted; it may not be empty
* @param classTree the class that contains {@code methodTree}
* @param methodTree the method or constructor tree
*/
// TODO: should field visibility matter? An access from outside the class might observe
// the declared type instead of a refined type. Issue a warning to alert users?
private void addInitialFieldValues(S store, ClassTree classTree, MethodTree methodTree) {
boolean isConstructor = TreeUtils.isConstructor(methodTree);
boolean isStaticMethod =
ElementUtils.isStatic(TreeUtils.elementFromDeclaration(methodTree));
TypeElement classEle = TreeUtils.elementFromDeclaration(classTree);
for (FieldInitialValue fieldInitialValue : analysis.getFieldInitialValues()) {
VariableElement varEle = fieldInitialValue.fieldDecl.getField();
boolean isStaticField = ElementUtils.isStatic(varEle);
if (isStaticMethod && !isStaticField) {
continue;
}
// Insert the value from the initializer of private final fields.
if (fieldInitialValue.initializer != null
// && varEle.getModifiers().contains(Modifier.PRIVATE)
&& ElementUtils.isFinal(varEle)
&& analysis.atypeFactory.isImmutable(ElementUtils.getType(varEle))) {
store.insertValue(fieldInitialValue.fieldDecl, fieldInitialValue.initializer);
// The type from the initializer is always more specific than (or equal to) the
// declared type of the field.
// So, if there is an initializer, there is no point in inserting the declared type
// below.
continue;
}
boolean isFieldOfCurrentClass = varEle.getEnclosingElement().equals(classEle);
// Maybe insert the declared type:
if (!isConstructor) {
// If it's not a constructor, use the declared type if the receiver of the method is
// fully initialized.
boolean isInitializedReceiver = !isNotFullyInitializedReceiver(methodTree);
if (isInitializedReceiver && isFieldOfCurrentClass) {
store.insertValue(fieldInitialValue.fieldDecl, fieldInitialValue.declared);
}
} else {
// If it is a constructor, then only use the declared type if the field has been
// initialized.
if (fieldInitialValue.initializer != null && isFieldOfCurrentClass) {
store.insertValue(fieldInitialValue.fieldDecl, fieldInitialValue.declared);
}
}
}
}
/**
* Adds information about effectively final variables (from outer scopes)
*
* @param store the store to add to
* @param enclosingElement the enclosing element of the code we are analyzing
*/
private void addFinalLocalValues(S store, Element enclosingElement) {
// add information about effectively final variables (from outer scopes)
for (Map.Entry e :
analysis.atypeFactory.getFinalLocalValues().entrySet()) {
VariableElement elem = e.getKey();
// TODO: There is a design flaw where the values of final local values leaks
// into other methods of the same class. For example, in
// class a { void b() {...} void c() {...} }
// final local values from b() would be visible in the store for c(),
// even though they should only be visible in b() and in classes
// defined inside the method body of b().
// This is partly because GenericAnnotatedTypeFactory.performFlowAnalysis does not call
// itself recursively to analyze inner classes, but instead pops classes off of a queue,
// and the information about known final local values is stored by
// GenericAnnotatedTypeFactory.analyze in GenericAnnotatedTypeFactory.flowResult, which
// is visible to all classes in the queue regardless of their level of recursion.
// We work around this here by ensuring that we only add a final local value to a
// method's store if that method is enclosed by the method where the local variables
// were declared.
// Find the enclosing method of the element
Element enclosingMethodOfVariableDeclaration = elem.getEnclosingElement();
if (enclosingMethodOfVariableDeclaration != null) {
// Now find all the enclosing methods of the code we are analyzing. If any one of
// them matches the above, then the final local variable value applies.
Element enclosingMethodOfCurrentMethod = enclosingElement;
while (enclosingMethodOfCurrentMethod != null) {
if (enclosingMethodOfVariableDeclaration.equals(
enclosingMethodOfCurrentMethod)) {
LocalVariable l = new LocalVariable(elem);
store.insertValue(l, e.getValue());
break;
}
enclosingMethodOfCurrentMethod =
enclosingMethodOfCurrentMethod.getEnclosingElement();
}
}
}
}
/**
* Returns true if the receiver of a method or constructor might not be fully initialized
* according to {@code analysis.atypeFactory.isNotFullyInitializedReceiver(methodDeclTree)}.
*
* @param methodDeclTree the declaration of the method or constructor
* @return true if the receiver of a method or constructor might not be fully initialized
* @see GenericAnnotatedTypeFactory#isNotFullyInitializedReceiver(MethodTree)
*/
@Pure
protected final boolean isNotFullyInitializedReceiver(MethodTree methodDeclTree) {
return analysis.atypeFactory.isNotFullyInitializedReceiver(methodDeclTree);
}
/**
* Add the information from all the preconditions of a method to the initial store in the method
* body.
*
* @param initialStore the initial store for the method body
* @param factory the type factory
* @param methodAst the AST for a method declaration
* @param methodDeclTree the declaration of the method; is a field of {@code methodAst}
* @param methodElement the element for the method
*/
protected void addInformationFromPreconditions(
S initialStore,
AnnotatedTypeFactory factory,
CFGMethod methodAst,
MethodTree methodDeclTree,
ExecutableElement methodElement) {
ContractsFromMethod contractsUtils = analysis.atypeFactory.getContractsFromMethod();
Set preconditions = contractsUtils.getPreconditions(methodElement);
StringToJavaExpression stringToJavaExpr =
stringExpr ->
StringToJavaExpression.atMethodBody(
stringExpr, methodDeclTree, analysis.checker);
for (Precondition p : preconditions) {
String stringExpr = p.expressionString;
AnnotationMirror annotation =
p.viewpointAdaptDependentTypeAnnotation(
analysis.atypeFactory, stringToJavaExpr, /* errorTree= */ null);
JavaExpression exprJe;
try {
// TODO: currently, these expressions are parsed at the declaration (i.e. here) and
// for every use. this could be optimized to store the result the first time.
// (same for other annotations)
exprJe =
StringToJavaExpression.atMethodBody(
stringExpr, methodDeclTree, analysis.checker);
} catch (JavaExpressionParseException e) {
// Errors are reported by BaseTypeVisitor.checkContractsAtMethodDeclaration().
continue;
}
initialStore.insertValuePermitNondeterministic(exprJe, annotation);
}
}
/**
* The default visitor returns the input information unchanged, or in the case of conditional
* input information, merged.
*/
@Override
public TransferResult visitNode(Node n, TransferInput in) {
V value = null;
// TODO: handle implicit/explicit this and go to correct factory method
Tree tree = n.getTree();
if (tree != null) {
if (TreeUtils.canHaveTypeAnnotation(tree)) {
value = getValueFromFactory(tree, n);
}
}
return createTransferResult(value, in);
}
/**
* Creates a TransferResult.
*
* This default implementation returns the input information unchanged, or in the case of
* conditional input information, merged.
*
* @param value the value; possibly null
* @param in the transfer input
* @return the input information, as a TransferResult
*/
@SideEffectFree
protected TransferResult createTransferResult(@Nullable V value, TransferInput in) {
if (in.containsTwoStores()) {
S thenStore = in.getThenStore();
S elseStore = in.getElseStore();
return new ConditionalTransferResult<>(
finishValue(value, thenStore, elseStore), thenStore, elseStore);
} else {
S store = in.getRegularStore();
return new RegularTransferResult<>(finishValue(value, store), store);
}
}
/**
* Creates a TransferResult just like the given one, but with the given value.
*
* This default implementation returns the input information unchanged, or in the case of
* conditional input information, merged.
*
* @param value the value; possibly null
* @param in the TransferResult to copy
* @return the input information
*/
@SideEffectFree
protected TransferResult recreateTransferResult(
@Nullable V value, TransferResult in) {
if (in.containsTwoStores()) {
S thenStore = in.getThenStore();
S elseStore = in.getElseStore();
return new ConditionalTransferResult<>(
finishValue(value, thenStore, elseStore), thenStore, elseStore);
} else {
S store = in.getRegularStore();
return new RegularTransferResult<>(finishValue(value, store), store);
}
}
@Override
public TransferResult visitClassName(ClassNameNode n, TransferInput in) {
// The tree underlying a class name is a type tree.
V value = null;
Tree tree = n.getTree();
if (tree != null) {
if (TreeUtils.canHaveTypeAnnotation(tree)) {
GenericAnnotatedTypeFactory>
factory = analysis.atypeFactory;
analysis.setCurrentTree(tree);
AnnotatedTypeMirror at = factory.getAnnotatedTypeFromTypeTree(tree);
analysis.setCurrentTree(null);
value = analysis.createAbstractValue(at);
}
}
return createTransferResult(value, in);
}
@Override
public TransferResult visitFieldAccess(FieldAccessNode n, TransferInput p) {
S store = p.getRegularStore();
V storeValue = store.getValue(n);
// look up value in factory, and take the more specific one
// TODO: handle cases, where this is not allowed (e.g. constructors in non-null type
// systems)
V factoryValue = getValueFromFactory(n.getTree(), n);
V value = moreSpecificValue(factoryValue, storeValue);
return new RegularTransferResult<>(finishValue(value, store), store);
}
@Override
public TransferResult visitArrayAccess(ArrayAccessNode n, TransferInput p) {
S store = p.getRegularStore();
V storeValue = store.getValue(n);
// look up value in factory, and take the more specific one
V factoryValue = getValueFromFactory(n.getTree(), n);
V value = moreSpecificValue(factoryValue, storeValue);
return new RegularTransferResult<>(finishValue(value, store), store);
}
/** Use the most specific type information available according to the store. */
@Override
public TransferResult visitLocalVariable(LocalVariableNode n, TransferInput in) {
S store = in.getRegularStore();
V valueFromStore = store.getValue(n);
V valueFromFactory = getValueFromFactory(n.getTree(), n);
V value = moreSpecificValue(valueFromFactory, valueFromStore);
return new RegularTransferResult<>(finishValue(value, store), store);
}
@Override
public TransferResult visitThis(ThisNode n, TransferInput in) {
S store = in.getRegularStore();
V valueFromStore = store.getValue(n);
V valueFromFactory = null;
V value = null;
Tree tree = n.getTree();
if (tree != null && TreeUtils.canHaveTypeAnnotation(tree)) {
valueFromFactory = getValueFromFactory(tree, n);
}
if (valueFromFactory == null) {
value = valueFromStore;
} else {
value = moreSpecificValue(valueFromFactory, valueFromStore);
}
return new RegularTransferResult<>(finishValue(value, store), store);
}
@Override
public TransferResult visitTernaryExpression(
TernaryExpressionNode n, TransferInput p) {
TransferResult result = super.visitTernaryExpression(n, p);
S thenStore = result.getThenStore();
S elseStore = result.getElseStore();
V thenValue = p.getValueOfSubNode(n.getThenOperand());
V elseValue = p.getValueOfSubNode(n.getElseOperand());
V resultValue = null;
if (thenValue != null && elseValue != null) {
// If a conditional expression is a poly expression, then its Java type is the type of
// its context. (For example, the type of the conditional expression in `Object o = b ?
// "" : "";` is `Object`, not `String`.)
// So, use the Java type of the conditional expression and the annotations for each
// branch.
TypeMirror conditionalType = TreeUtils.typeOf(n.getTree());
// The resulting abstract value is the merge of the 'then' and 'else' branch.
resultValue = thenValue.leastUpperBound(elseValue, conditionalType);
}
V finishedValue = finishValue(resultValue, thenStore, elseStore);
return new ConditionalTransferResult<>(finishedValue, thenStore, elseStore);
}
@Override
public TransferResult visitSwitchExpressionNode(
SwitchExpressionNode n, TransferInput vsTransferInput) {
return visitLocalVariable(n.getSwitchExpressionVar(), vsTransferInput);
}
/** Reverse the role of the 'thenStore' and 'elseStore'. */
@Override
public TransferResult visitConditionalNot(ConditionalNotNode n, TransferInput p) {
TransferResult result = super.visitConditionalNot(n, p);
S thenStore = result.getThenStore();
S elseStore = result.getElseStore();
return new ConditionalTransferResult<>(result.getResultValue(), elseStore, thenStore);
}
@Override
public TransferResult visitEqualTo(EqualToNode n, TransferInput p) {
TransferResult res = super.visitEqualTo(n, p);
Node leftN = n.getLeftOperand();
Node rightN = n.getRightOperand();
V leftV = p.getValueOfSubNode(leftN);
V rightV = p.getValueOfSubNode(rightN);
if (res.containsTwoStores()
&& (NodeUtils.isConstantBoolean(leftN, false)
|| NodeUtils.isConstantBoolean(rightN, false))) {
S thenStore = res.getElseStore();
S elseStore = res.getThenStore();
res = new ConditionalTransferResult<>(res.getResultValue(), thenStore, elseStore);
}
// if annotations differ, use the one that is more precise for both
// sides (and add it to the store if possible)
res = strengthenAnnotationOfEqualTo(res, leftN, rightN, leftV, rightV, false);
res = strengthenAnnotationOfEqualTo(res, rightN, leftN, rightV, leftV, false);
return res;
}
@Override
public TransferResult visitNotEqual(NotEqualNode n, TransferInput p) {
TransferResult res = super.visitNotEqual(n, p);
Node leftN = n.getLeftOperand();
Node rightN = n.getRightOperand();
V leftV = p.getValueOfSubNode(leftN);
V rightV = p.getValueOfSubNode(rightN);
if (res.containsTwoStores()
&& (NodeUtils.isConstantBoolean(leftN, true)
|| NodeUtils.isConstantBoolean(rightN, true))) {
S thenStore = res.getElseStore();
S elseStore = res.getThenStore();
res = new ConditionalTransferResult<>(res.getResultValue(), thenStore, elseStore);
}
// if annotations differ, use the one that is more precise for both
// sides (and add it to the store if possible)
res = strengthenAnnotationOfEqualTo(res, leftN, rightN, leftV, rightV, true);
res = strengthenAnnotationOfEqualTo(res, rightN, leftN, rightV, leftV, true);
return res;
}
/**
* Refine the annotation of {@code secondNode} if the annotation {@code secondValue} is less
* precise than {@code firstValue}. This is possible, if {@code secondNode} is an expression
* that is tracked by the store (e.g., a local variable or a field). Clients usually call this
* twice with {@code firstNode} and {@code secondNode} reversed, to refine each of them.
*
* Note that when overriding this method, when a new type is inserted into the store, {@link
* #splitAssignments} should be called, and the new type should be inserted into the store for
* each of the resulting nodes.
*
* @param firstNode the node that might be more precise
* @param secondNode the node whose type to possibly refine
* @param firstValue the abstract value that might be more precise
* @param secondValue the abstract value that might be less precise
* @param res the previous result
* @param notEqualTo if true, indicates that the logic is flipped (i.e., the information is
* added to the {@code elseStore} instead of the {@code thenStore}) for a not-equal
* comparison.
* @return the conditional transfer result (if information has been added), or {@code res}
*/
protected TransferResult strengthenAnnotationOfEqualTo(
TransferResult res,
Node firstNode,
Node secondNode,
V firstValue,
V secondValue,
boolean notEqualTo) {
if (firstValue != null) {
// Only need to insert if the second value is actually different.
if (!firstValue.equals(secondValue)) {
List secondParts = splitAssignments(secondNode);
for (Node secondPart : secondParts) {
JavaExpression secondInternal = JavaExpression.fromNode(secondPart);
if (!secondInternal.isDeterministic(analysis.atypeFactory)) {
continue;
}
if (CFAbstractStore.canInsertJavaExpression(secondInternal)) {
S thenStore = res.getThenStore();
S elseStore = res.getElseStore();
if (notEqualTo) {
elseStore.insertValue(secondInternal, firstValue);
} else {
thenStore.insertValue(secondInternal, firstValue);
}
// To handle `(a = b = c) == x`, repeat for all insertable receivers of
// splitted assignments instead of returning.
res =
new ConditionalTransferResult<>(
res.getResultValue(), thenStore, elseStore);
}
}
}
}
return res;
}
/**
* Takes a node, and either returns the node itself again (as a singleton list), or if the node
* is an assignment node, returns the lhs and rhs (where splitAssignments is applied recursively
* to the rhs -- that is, it is possible that the rhs does not appear in the result, but rather
* its lhs and rhs do).
*
* @param node possibly an assignment node
* @return a list containing all the right- and left-hand sides in the given assignment node; it
* contains just the node itself if it is not an assignment)
*/
@SideEffectFree
protected List splitAssignments(Node node) {
if (node instanceof AssignmentNode) {
List result = new ArrayList<>(2);
AssignmentNode a = (AssignmentNode) node;
result.add(a.getTarget());
result.addAll(splitAssignments(a.getExpression()));
return result;
} else {
return Collections.singletonList(node);
}
}
@Override
public TransferResult visitAssignment(AssignmentNode n, TransferInput in) {
Node lhs = n.getTarget();
Node rhs = n.getExpression();
V rhsValue = in.getValueOfSubNode(rhs);
/* NO-AFU
if (shouldPerformWholeProgramInference(n.getTree(), lhs.getTree())) {
// Fields defined in interfaces are LocalVariableNodes with ElementKind of FIELD.
if (lhs instanceof FieldAccessNode
|| (lhs instanceof LocalVariableNode
&& ((LocalVariableNode) lhs).getElement().getKind() == ElementKind.FIELD)) {
// Updates inferred field type
analysis.atypeFactory.getWholeProgramInference().updateFromFieldAssignment(lhs, rhs);
} else if (lhs instanceof LocalVariableNode
&& ((LocalVariableNode) lhs).getElement().getKind() == ElementKind.PARAMETER) {
// lhs is a formal parameter of some method
VariableElement param = ((LocalVariableNode) lhs).getElement();
analysis
.atypeFactory
.getWholeProgramInference()
.updateFromFormalParameterAssignment((LocalVariableNode) lhs, rhs, param);
}
*/
if (n.isSynthetic() && in.containsTwoStores()) {
// This is a synthetic assignment node created for a ternary expression. In this case
// the `then` and `else` store are not merged.
S thenStore = in.getThenStore();
S elseStore = in.getElseStore();
processCommonAssignment(in, lhs, rhs, thenStore, rhsValue);
processCommonAssignment(in, lhs, rhs, elseStore, rhsValue);
return new ConditionalTransferResult<>(
finishValue(rhsValue, thenStore, elseStore), thenStore, elseStore);
} else {
S store = in.getRegularStore();
processCommonAssignment(in, lhs, rhs, store, rhsValue);
return new RegularTransferResult<>(finishValue(rhsValue, store), store);
}
}
@Override
public TransferResult visitReturn(ReturnNode n, TransferInput p) {
TransferResult result = super.visitReturn(n, p);
/* NO-AFU
if (shouldPerformWholeProgramInference(n.getTree())) {
// Retrieves class containing the method
ClassTree classTree = analysis.getContainingClass(n.getTree());
// classTree is null e.g. if this is a return statement in a lambda.
if (classTree == null) {
return result;
}
ClassSymbol classSymbol = (ClassSymbol) TreeUtils.elementFromDeclaration(classTree);
ExecutableElement methodElem =
TreeUtils.elementFromDeclaration(analysis.getContainingMethod(n.getTree()));
Map overriddenMethods =
AnnotatedTypes.overriddenMethods(
analysis.atypeFactory.getElementUtils(), analysis.atypeFactory, methodElem);
// Updates the inferred return type of the method
analysis
.atypeFactory
.getWholeProgramInference()
.updateFromReturn(
n, classSymbol, analysis.getContainingMethod(n.getTree()), overriddenMethods);
}
*/
return result;
}
@Override
public TransferResult visitLambdaResultExpression(
LambdaResultExpressionNode n, TransferInput in) {
return n.getResult().accept(this, in);
}
/**
* Determine abstract value of right-hand side and update the store accordingly.
*
* @param in the store(s) before the assignment
* @param lhs the left-hand side of the assignment
* @param rhs the right-hand side of the assignment
* @param store the regular input store (from {@code in})
* @param rhsValue the value of the right-hand side of the assignment
*/
protected void processCommonAssignment(
TransferInput in, Node lhs, Node rhs, S store, V rhsValue) {
// update information in the store
store.updateForAssignment(lhs, rhsValue);
}
@Override
public TransferResult visitObjectCreation(ObjectCreationNode n, TransferInput p) {
/* NO-AFU
if (shouldPerformWholeProgramInference(n.getTree())) {
NewClassTree newClassTree = n.getTree();
// Can't infer annotations on an anonymous constructor, so use the super constructor.
ExecutableElement constructorElt = TreeUtils.getSuperConstructor(newClassTree);
if (newClassTree.getClassBody() == null || !TreeUtils.hasSyntheticArgument(newClassTree)) {
// TODO: WPI could be changed to handle the synthetic argument, but for now just
// don't infer annotations for those new class trees.
analysis
.atypeFactory
.getWholeProgramInference()
.updateFromObjectCreation(n, constructorElt, p.getRegularStore());
}
}
*/
NewClassTree newClassTree = n.getTree();
ExecutableElement constructorElt = TreeUtils.getSuperConstructor(newClassTree);
S store = p.getRegularStore();
// add new information based on postcondition
processPostconditions(n, store, constructorElt, newClassTree);
return super.visitObjectCreation(n, p);
}
@Override
public TransferResult visitMethodInvocation(
MethodInvocationNode n, TransferInput in) {
S store = in.getRegularStore();
ExecutableElement method = n.getTarget().getMethod();
/* NO-AFU
// Perform WPI before the store has been side-effected.
if (shouldPerformWholeProgramInference(n.getTree(), method)) {
// Updates the inferred parameter types of the invoked method.
analysis.atypeFactory
.getWholeProgramInference()
.updateFromMethodInvocation(n, method, store);
}
*/
ExpressionTree invocationTree = n.getTree();
// Determine the abstract value for the method call.
// look up the call's value from factory
V factoryValue = (invocationTree == null) ? null : getValueFromFactory(invocationTree, n);
// look up the call's value in the store (if possible)
V storeValue = store.getValue(n);
V resValue = moreSpecificValue(factoryValue, storeValue);
store.updateForMethodCall(n, analysis.atypeFactory, resValue);
// add new information based on postcondition
processPostconditions(n, store, method, invocationTree);
if (TypesUtils.isBooleanType(method.getReturnType())) {
S thenStore = store;
S elseStore = thenStore.copy();
// add new information based on conditional postcondition
processConditionalPostconditions(n, method, invocationTree, thenStore, elseStore);
return new ConditionalTransferResult<>(
finishValue(resValue, thenStore, elseStore), thenStore, elseStore);
} else {
return new RegularTransferResult<>(finishValue(resValue, store), store);
}
}
@Override
public TransferResult visitDeconstructorPattern(
DeconstructorPatternNode n, TransferInput in) {
// TODO: Implement getting the type of a DeconstructorPatternTree.
V value = null;
return createTransferResult(value, in);
}
@Override
public TransferResult visitInstanceOf(InstanceOfNode node, TransferInput in) {
TransferResult result = super.visitInstanceOf(node, in);
for (LocalVariableNode bindingVar : node.getBindingVariables()) {
JavaExpression expr = JavaExpression.fromNode(bindingVar);
AnnotatedTypeMirror expType =
analysis.atypeFactory.getAnnotatedType(node.getTree().getExpression());
for (AnnotationMirror anno : expType.getAnnotations()) {
in.getRegularStore().insertOrRefine(expr, anno);
}
}
// The "reference type" is the type after "instanceof".
Tree refTypeTree = node.getTree().getType();
if (refTypeTree != null && refTypeTree.getKind() == Tree.Kind.ANNOTATED_TYPE) {
AnnotatedTypeMirror refType = analysis.atypeFactory.getAnnotatedType(refTypeTree);
AnnotatedTypeMirror expType =
analysis.atypeFactory.getAnnotatedType(node.getTree().getExpression());
if (analysis.atypeFactory.getTypeHierarchy().isSubtype(refType, expType)
&& !refType.getAnnotations().equals(expType.getAnnotations())
&& !expType.getAnnotations().isEmpty()) {
JavaExpression expr = JavaExpression.fromTree(node.getTree().getExpression());
for (AnnotationMirror anno : refType.getAnnotations()) {
in.getRegularStore().insertOrRefine(expr, anno);
}
return new RegularTransferResult<>(result.getResultValue(), in.getRegularStore());
}
}
return result;
}
/* NO-AFU
* Returns true if whole-program inference should be performed. If the tree is in the scope of
* a @SuppressWarnings, then this method returns false.
*
* @param tree a tree
* @return whether to perform whole-program inference on the tree
*/
/* NO-AFU
protected boolean shouldPerformWholeProgramInference(Tree tree) {
TreePath path = this.analysis.atypeFactory.getPath(tree);
return infer && (tree == null || !analysis.checker.shouldSuppressWarnings(path, ""));
}
*/
/* NO-AFU
* Returns true if whole-program inference should be performed. If the expressionTree or lhsTree
* is in the scope of a @SuppressWarnings, then this method returns false.
*
* @param expressionTree the right-hand side of an assignment
* @param lhsTree the left-hand side of an assignment
* @return whether to perform whole-program inference
*/
/* NO-AFU
protected boolean shouldPerformWholeProgramInference(Tree expressionTree, Tree lhsTree) {
// Check that infer is true and the tree isn't in scope of a @SuppressWarnings
// before calling InternalUtils.symbol(lhs).
if (!shouldPerformWholeProgramInference(expressionTree)) {
return false;
}
Element elt = TreeUtils.elementFromTree(lhsTree);
return !analysis.checker.shouldSuppressWarnings(elt, "");
}
*/
/* NO-AFU
* Returns true if whole-program inference should be performed. If the tree or element is in the
* scope of a @SuppressWarnings, then this method returns false.
*
* @param tree a tree
* @param elt its element
* @return whether to perform whole-program inference
*/
/* NO-AFU
private boolean shouldPerformWholeProgramInference(Tree tree, Element elt) {
return shouldPerformWholeProgramInference(tree)
&& !analysis.checker.shouldSuppressWarnings(elt, "");
}
*/
/**
* Add information from the postconditions of a method to the store after an invocation.
*
* @param invocationNode a method call or an object creation
* @param store a store; is side-effected by this method
* @param executableElement the method or constructor being called
* @param invocationTree the tree for the method call or for the object creation
*/
protected void processPostconditions(
Node invocationNode,
S store,
ExecutableElement executableElement,
ExpressionTree invocationTree) {
ContractsFromMethod contractsUtils = analysis.atypeFactory.getContractsFromMethod();
Set postconditions = contractsUtils.getPostconditions(executableElement);
processPostconditionsAndConditionalPostconditions(
invocationNode, invocationTree, store, null, postconditions);
}
/**
* Add information from the conditional postconditions of a method to the stores after an
* invocation.
*
* @param invocationNode a method call
* @param methodElement the method being called
* @param invocationTree the tree for the method call
* @param thenStore the "then" store; is side-effected by this method
* @param elseStore the "else" store; is side-effected by this method
*/
protected void processConditionalPostconditions(
MethodInvocationNode invocationNode,
ExecutableElement methodElement,
ExpressionTree invocationTree,
S thenStore,
S elseStore) {
ContractsFromMethod contractsUtils = analysis.atypeFactory.getContractsFromMethod();
Set conditionalPostconditions =
contractsUtils.getConditionalPostconditions(methodElement);
processPostconditionsAndConditionalPostconditions(
invocationNode, invocationTree, thenStore, elseStore, conditionalPostconditions);
}
/**
* Add information from the postconditions and conditional postconditions of a method to the
* stores after an invocation.
*
* @param invocationNode a method call node or an object creation node
* @param invocationTree the tree for the method call or for the object creation
* @param thenStore the "then" store; is side-effected by this method
* @param elseStore the "else" store; is side-effected by this method
* @param postconditions the postconditions
*/
private void processPostconditionsAndConditionalPostconditions(
Node invocationNode,
ExpressionTree invocationTree,
S thenStore,
S elseStore,
Set postconditions) {
StringToJavaExpression stringToJavaExpr = null;
if (invocationNode instanceof MethodInvocationNode) {
stringToJavaExpr =
stringExpr ->
StringToJavaExpression.atMethodInvocation(
stringExpr,
(MethodInvocationNode) invocationNode,
analysis.checker);
} else if (invocationNode instanceof ObjectCreationNode) {
stringToJavaExpr =
stringExpr ->
StringToJavaExpression.atConstructorInvocation(
stringExpr, (NewClassTree) invocationTree, analysis.checker);
} else {
throw new BugInCF(
"CFAbstractTransfer.processPostconditionsAndConditionalPostconditions"
+ " expects a MethodInvocationNode or ObjectCreationNode argument;"
+ " received a "
+ invocationNode.getClass().getSimpleName());
}
for (Contract p : postconditions) {
// Viewpoint-adapt to the method use (the call site).
AnnotationMirror anno =
p.viewpointAdaptDependentTypeAnnotation(
analysis.atypeFactory, stringToJavaExpr, /* errorTree= */ null);
String expressionString = p.expressionString;
try {
JavaExpression je = stringToJavaExpr.toJavaExpression(expressionString);
// "insertOrRefine" is called so that the postcondition information is added to any
// existing information rather than replacing it. If the called method is not
// side-effect-free, then the values that might have been changed by the method call
// are removed from the store before this method is called.
if (p.kind == Contract.Kind.CONDITIONALPOSTCONDITION) {
if (((ConditionalPostcondition) p).resultValue) {
thenStore.insertOrRefinePermitNondeterministic(je, anno);
} else {
elseStore.insertOrRefinePermitNondeterministic(je, anno);
}
} else {
thenStore.insertOrRefinePermitNondeterministic(je, anno);
}
} catch (JavaExpressionParseException e) {
// report errors here
if (e.isFlowParseError()) {
Object[] args = new Object[e.args.length + 1];
args[0] =
ElementUtils.getSimpleSignature(
(ExecutableElement) TreeUtils.elementFromUse(invocationTree));
System.arraycopy(e.args, 0, args, 1, e.args.length);
analysis.checker.reportError(
invocationTree, "flowexpr.parse.error.postcondition", args);
} else {
analysis.checker.report(invocationTree, e.getDiagMessage());
}
}
}
}
/** A case produces no value, but it may imply some facts about switch selector expression. */
@Override
public TransferResult visitCase(CaseNode n, TransferInput in) {
S store = in.getRegularStore();
TransferResult lubResult = null;
// Case operands are the case constants. For example, A, B and C in case A, B, C:.
// This method refines the type of the selector expression and the synthetic variable that
// represents the selector expression to the type of the case constant if it is more
// precise.
// If there are multiple case constants then a new store is created for each case constant
// and then they are lubbed. This method returns the lubbed result.
for (Node caseOperand : n.getCaseOperands()) {
TransferResult result =
new ConditionalTransferResult<>(
finishValue(null, store),
in.getThenStore().copy(),
in.getElseStore().copy(),
false);
V caseValue = in.getValueOfSubNode(caseOperand);
AssignmentNode assign = n.getSwitchOperand();
V switchValue = store.getValue(JavaExpression.fromNode(assign.getTarget()));
result =
strengthenAnnotationOfEqualTo(
result,
caseOperand,
assign.getExpression(),
caseValue,
switchValue,
false);
// Update value of switch temporary variable
result =
strengthenAnnotationOfEqualTo(
result, caseOperand, assign.getTarget(), caseValue, switchValue, false);
// Lub the result of one case label constant with the result of the others.
if (lubResult == null) {
lubResult = result;
} else {
S thenStore = lubResult.getThenStore().leastUpperBound(result.getThenStore());
S elseStore = lubResult.getElseStore().leastUpperBound(result.getElseStore());
lubResult =
new ConditionalTransferResult<>(
null,
thenStore,
elseStore,
lubResult.storeChanged() || result.storeChanged());
}
}
return lubResult;
}
/**
* In a cast {@code (@A C) e} of some expression {@code e} to a new type {@code @A C}, we
* usually take the annotation of the type {@code C} (here {@code @A}). However, if the inferred
* annotation of {@code e} is more precise, we keep that one.
*/
// @Override
// public TransferResult visitTypeCast(TypeCastNode n,
// TransferInput p) {
// TransferResult result = super.visitTypeCast(n, p);
// V value = result.getResultValue();
// V operandValue = p.getValueOfSubNode(n.getOperand());
// // Normally we take the value of the type cast node. However, if the old
// // flow-refined value was more precise, we keep that value.
// V resultValue = moreSpecificValue(value, operandValue);
// result.setResultValue(resultValue);
// return result;
// }
/**
* Returns the abstract value of {@code (value1, value2)} that is more specific. If the two are
* incomparable, then {@code value1} is returned.
*
* @param value1 an abstract value
* @param value2 another abstract value
* @return the more specific value of the two parameters, or, if they are incomparable, {@code
* value1}
*/
@Pure
public V moreSpecificValue(V value1, V value2) {
if (value1 == null) {
return value2;
}
if (value2 == null) {
return value1;
}
return value1.mostSpecific(value2, value1);
}
@Override
public TransferResult visitVariableDeclaration(
VariableDeclarationNode n, TransferInput p) {
S store = p.getRegularStore();
return new RegularTransferResult<>(finishValue(null, store), store);
}
@Override
public TransferResult visitWideningConversion(
WideningConversionNode n, TransferInput p) {
TransferResult result = super.visitWideningConversion(n, p);
// Combine annotations from the operand with the wide type
V operandValue = p.getValueOfSubNode(n.getOperand());
V widenedValue = getWidenedValue(n.getType(), operandValue);
result.setResultValue(widenedValue);
return result;
}
/**
* Returns an abstract value with the given {@code type} and the annotations from {@code
* annotatedValue}, adapted for narrowing. This is only called at a narrowing conversion.
*
* @param type the type to narrow to
* @param annotatedValue the type to narrow from
* @return an abstract value with the given {@code type} and the annotations from {@code
* annotatedValue}; returns null if {@code annotatedValue} is null
*/
@SideEffectFree
protected @PolyNull V getNarrowedValue(TypeMirror type, @PolyNull V annotatedValue) {
if (annotatedValue == null) {
return null;
}
AnnotationMirrorSet narrowedAnnos =
analysis.atypeFactory.getNarrowedAnnotations(
annotatedValue.getAnnotations(),
annotatedValue.getUnderlyingType().getKind(),
type.getKind());
return analysis.createAbstractValue(narrowedAnnos, type);
}
/**
* Returns an abstract value with the given {@code type} and the annotations from {@code
* annotatedValue}, adapted for widening. This is only called at a widening conversion.
*
* @param type the type to widen to
* @param annotatedValue the type to widen from
* @return an abstract value with the given {@code type} and the annotations from {@code
* annotatedValue}; returns null if {@code annotatedValue} is null
*/
@SideEffectFree
protected @PolyNull V getWidenedValue(TypeMirror type, @PolyNull V annotatedValue) {
if (annotatedValue == null) {
return null;
}
AnnotationMirrorSet widenedAnnos =
analysis.atypeFactory.getWidenedAnnotations(
annotatedValue.getAnnotations(),
annotatedValue.getUnderlyingType().getKind(),
type.getKind());
return analysis.createAbstractValue(widenedAnnos, type);
}
@Override
public TransferResult visitNarrowingConversion(
NarrowingConversionNode n, TransferInput p) {
TransferResult result = super.visitNarrowingConversion(n, p);
// Combine annotations from the operand with the narrow type
V operandValue = p.getValueOfSubNode(n.getOperand());
V narrowedValue = getNarrowedValue(n.getType(), operandValue);
result.setResultValue(narrowedValue);
return result;
}
@Override
public TransferResult visitStringConversion(
StringConversionNode n, TransferInput p) {
TransferResult result = super.visitStringConversion(n, p);
result.setResultValue(p.getValueOfSubNode(n.getOperand()));
return result;
}
@Override
public TransferResult visitExpressionStatement(
ExpressionStatementNode n, TransferInput vsTransferInput) {
// Merge the input
S info = vsTransferInput.getRegularStore();
return new RegularTransferResult<>(finishValue(null, info), info);
}
/**
* Inserts newAnno as the value into all stores (conditional or not) in the result for node.
* This is a utility method for subclasses.
*
* @param result the TransferResult holding the stores to modify
* @param target the receiver whose value should be modified
* @param newAnno the new value
*/
protected static void insertIntoStores(
TransferResult result,
JavaExpression target,
AnnotationMirror newAnno) {
if (result.containsTwoStores()) {
result.getThenStore().insertValue(target, newAnno);
result.getElseStore().insertValue(target, newAnno);
} else {
result.getRegularStore().insertValue(target, newAnno);
}
}
}