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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.codehaus.groovy.ast;
import org.codehaus.groovy.ast.tools.GenericsUtils;
import org.codehaus.groovy.ast.tools.WideningCategories;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import static org.codehaus.groovy.ast.ClassHelper.isObjectType;
import static org.codehaus.groovy.transform.stc.StaticTypeCheckingSupport.implementsInterfaceOrIsSubclassOf;
/**
* This class is used to describe generic type signatures for ClassNodes.
*
* @see ClassNode
*/
public class GenericsType extends ASTNode {
public static final GenericsType[] EMPTY_ARRAY = new GenericsType[0];
private String name;
private ClassNode type;
private final ClassNode lowerBound;
private final ClassNode[] upperBounds;
private boolean placeholder, resolved, wildcard;
public GenericsType(final ClassNode type, final ClassNode[] upperBounds, final ClassNode lowerBound) {
setType(type);
this.lowerBound = lowerBound;
this.upperBounds = upperBounds;
this.placeholder = type.isGenericsPlaceHolder();
setName(placeholder ? type.getUnresolvedName() : type.getName());
}
public GenericsType(final ClassNode basicType) {
this(basicType, null, null);
}
public ClassNode getType() {
return type;
}
public void setType(final ClassNode type) {
this.type = Objects.requireNonNull(type); // TODO: ensure type is not primitive
}
@Override
public String toString() {
return toString(this, new HashSet<>());
}
private static String toString(final GenericsType gt, final Set<String> visited) {
String name = gt.getName();
ClassNode type = gt.getType();
boolean wildcard = gt.isWildcard();
boolean placeholder = gt.isPlaceholder();
ClassNode lowerBound = gt.getLowerBound();
ClassNode[] upperBounds = gt.getUpperBounds();
if (placeholder) visited.add(name);
StringBuilder ret = new StringBuilder(wildcard || placeholder ? name : genericsBounds(type, visited));
if (lowerBound != null) {
ret.append(" super ").append(genericsBounds(lowerBound, visited));
} else if (upperBounds != null
// T extends Object should just be printed as T
&& !(placeholder && upperBounds.length == 1 && !upperBounds[0].isGenericsPlaceHolder() && upperBounds[0].getName().equals(ClassHelper.OBJECT))) {
ret.append(" extends ");
for (int i = 0, n = upperBounds.length; i < n; i += 1) {
if (i != 0) ret.append(" & ");
ret.append(genericsBounds(upperBounds[i], visited));
}
}
return ret.toString();
}
private static String genericsBounds(final ClassNode theType, final Set<String> visited) {
if (theType instanceof WideningCategories.LowestUpperBoundClassNode) {
var ret = new java.util.StringJoiner(" & ");
for (ClassNode type : theType.asGenericsType().getUpperBounds()) {
ret.add(genericsBounds(type, visited));
}
return ret.toString();
}
StringBuilder ret = appendName(theType, new StringBuilder());
GenericsType[] genericsTypes = theType.getGenericsTypes();
if (genericsTypes != null && genericsTypes.length > 0
&& !theType.isGenericsPlaceHolder()) { // GROOVY-10583
ret.append('<');
for (int i = 0, n = genericsTypes.length; i < n; i += 1) {
if (i != 0) ret.append(", ");
GenericsType type = genericsTypes[i];
if (type.isPlaceholder() && visited.contains(type.getName())) {
ret.append(type.getName());
} else {
ret.append(toString(type, visited));
}
}
ret.append('>');
}
return ret.toString();
}
private static StringBuilder appendName(final ClassNode theType, final StringBuilder sb) {
if (theType.isArray()) {
appendName(theType.getComponentType(), sb).append("[]");
} else if (theType.isGenericsPlaceHolder()) {
sb.append(theType.getUnresolvedName());
} else if (theType.getOuterClass() != null) {
String parentClassNodeName = theType.getOuterClass().getName();
if (Modifier.isStatic(theType.getModifiers()) || theType.isInterface()) {
sb.append(parentClassNodeName);
} else {
ClassNode outerClass = theType.getNodeMetaData("outer.class");
if (outerClass == null) outerClass = theType.getOuterClass();
sb.append(genericsBounds(outerClass, new HashSet<>()));
}
sb.append('.');
sb.append(theType.getName(), parentClassNodeName.length() + 1, theType.getName().length());
} else {
sb.append(theType.getName());
}
return sb;
}
public String getName() {
return (isWildcard() ? "?" : name);
}
public void setName(final String name) {
this.name = Objects.requireNonNull(name);
}
public boolean isResolved() {
return resolved;
}
public void setResolved(final boolean resolved) {
this.resolved = resolved;
}
public boolean isPlaceholder() {
return placeholder;
}
public void setPlaceholder(final boolean placeholder) {
this.placeholder = placeholder;
this.resolved = resolved || placeholder;
this.wildcard = wildcard && !placeholder;
getType().setGenericsPlaceHolder(placeholder);
}
public boolean isWildcard() {
return wildcard;
}
public void setWildcard(final boolean wildcard) {
this.wildcard = wildcard;
this.placeholder = placeholder && !wildcard;
}
public ClassNode getLowerBound() {
return lowerBound;
}
public ClassNode[] getUpperBounds() {
return upperBounds;
}
//--------------------------------------------------------------------------
/**
* Determines if the provided type is compatible with this specification.
* The check is complete, meaning that nested generics are also checked.
*/
public boolean isCompatibleWith(final ClassNode classNode) {
GenericsType[] genericsTypes = classNode.getGenericsTypes();
if (genericsTypes != null && genericsTypes.length == 0) {
return true; // diamond always matches
}
if (classNode.isGenericsPlaceHolder()) {
if (genericsTypes == null) {
return true;
}
String name = genericsTypes[0].getName();
if (!isWildcard()) {
return name.equals(getName());
}
if (getLowerBound() != null) {
// check for "? super T" vs "T"
ClassNode lowerBound = getLowerBound();
if (name.equals(lowerBound.getUnresolvedName())) {
return true;
}
} else if (getUpperBounds() != null) {
// check for "? extends T & I" vs "T" or "I"
for (ClassNode upperBound : getUpperBounds()) {
if (name.equals(upperBound.getUnresolvedName())) {
return true;
}
}
}
// check for "? extends/super X" vs "T extends/super X"
return checkGenerics(classNode);
}
if (isWildcard() || isPlaceholder()) {
ClassNode lowerBound = getLowerBound();
if (lowerBound != null) {
// test bound and type in reverse for lower bound vs upper bound
if (!implementsInterfaceOrIsSubclassOf(lowerBound, classNode)) {
return false;
}
return checkGenerics(classNode);
}
ClassNode[] upperBounds = getUpperBounds();
if (upperBounds != null) {
// check that provided type extends or implements all upper bounds
for (ClassNode upperBound : upperBounds) {
if (!implementsInterfaceOrIsSubclassOf(classNode, upperBound)) {
return false;
}
}
// if the provided type is a subclass of the upper bound(s) then
// check that the generic types supplied are compatible with this
// for example, this spec could be "Type<X>" but type is "Type<Y>"
return checkGenerics(classNode);
}
// if there are no bounds, the generic type is basically Object and everything is compatible
return true;
}
// not placeholder or wildcard; no covariance allowed for type or bound(s)
return classNode.equals(getType()) && compareGenericsWithBound(classNode, getType());
}
/**
* Compares the bounds of this generics specification against the given type
* for compatibility. Ex: String would satisfy &lt;? extends CharSequence>.
*/
private boolean checkGenerics(final ClassNode classNode) {
ClassNode lowerBound = getLowerBound();
if (lowerBound != null) {
return compareGenericsWithBound(classNode, lowerBound);
}
ClassNode[] upperBounds = getUpperBounds();
if (upperBounds != null) {
for (ClassNode upperBound : upperBounds) {
if (!compareGenericsWithBound(classNode, upperBound)) {
return false;
}
}
}
return true;
}
/**
* Given a parameterized type (List&lt;String&gt; for example), checks that its
* generic types are compatible with those from a bound.
* @param classNode the classnode from which we will compare generics types
* @param bound the bound to which the types will be compared
* @return true if generics are compatible
*/
private static boolean compareGenericsWithBound(final ClassNode classNode, final ClassNode bound) {
if (classNode == null) return false;
if (bound.getGenericsTypes() == null
|| classNode.isGenericsPlaceHolder() // GROOVY-10556: "T" vs "C<T extends C<?>>" bound
|| (classNode.getGenericsTypes() == null && classNode.redirect().getGenericsTypes() != null))
// if the bound is not using generics or the class node is a raw type, there's nothing to compare
return true;
if (!classNode.equals(bound)) {
// the class nodes are on different types
// in this situation, we must choose the correct execution path : either the bound
// is an interface and we must find the implementing interface from the classnode
// to compare their parameterized generics, or the bound is a regular class and we
// must compare the bound with a superclass
if (bound.isInterface()) {
// iterate over all interfaces to check if any corresponds to the bound we are
// comparing to
for (ClassNode face : classNode.getAllInterfaces()) {
if (face.equals(bound)) {
// when we obtain an interface, the types represented by the interface
// class node are not parameterized. This means that we must create a
// new class node with the parameterized types that the current class node
// has defined.
if (face.getGenericsTypes() != null) {
face = GenericsUtils.parameterizeType(classNode, face);
}
return compareGenericsWithBound(face, bound);
}
}
}
if (bound instanceof WideningCategories.LowestUpperBoundClassNode) {
// another special case here, where the bound is a "virtual" type
// we must then check the superclass and the interfaces
if (compareGenericsWithBound(classNode, bound.getSuperClass())
&& Arrays.stream(bound.getInterfaces()).allMatch(face -> compareGenericsWithBound(classNode, face))) {
return true;
}
}
if (isObjectType(classNode)) {
return false;
}
ClassNode superClass = classNode.getUnresolvedSuperClass();
if (superClass == null) {
superClass = ClassHelper.OBJECT_TYPE;
} else if (superClass.getGenericsTypes() != null) {
superClass = GenericsUtils.parameterizeType(classNode, superClass);
}
return compareGenericsWithBound(superClass, bound);
}
GenericsType[] cnTypes = classNode.getGenericsTypes();
if (cnTypes == null) {
cnTypes = classNode.redirect().getGenericsTypes();
}
if (cnTypes == null) {
// may happen if generic type is Foo<T extends Foo> and ClassNode is Foo -> Foo
return true;
}
GenericsType[] redirectBoundGenericTypes = bound.redirect().getGenericsTypes();
Map<GenericsTypeName, GenericsType> boundPlaceHolders = GenericsUtils.extractPlaceholders(bound);
Map<GenericsTypeName, GenericsType> classNodePlaceholders = GenericsUtils.extractPlaceholders(classNode);
boolean match = true;
for (int i = 0; redirectBoundGenericTypes != null && i < redirectBoundGenericTypes.length && match; i += 1) {
GenericsType redirectBoundType = redirectBoundGenericTypes[i];
GenericsType classNodeType = cnTypes[i];
if (classNodeType.isPlaceholder()) {
GenericsTypeName name = new GenericsTypeName(classNodeType.getName());
if (redirectBoundType.isPlaceholder()) {
GenericsTypeName gtn = new GenericsTypeName(redirectBoundType.getName());
match = name.equals(gtn)
|| name.equals(new GenericsTypeName("#" + redirectBoundType.getName()));
if (!match) {
GenericsType boundGenericsType = boundPlaceHolders.get(gtn);
if (boundGenericsType != null) {
if (boundGenericsType.isPlaceholder()) {
match = true;
} else if (boundGenericsType.isWildcard()) {
if (boundGenericsType.getUpperBounds() != null) { // ? supports single bound only
match = classNodeType.isCompatibleWith(boundGenericsType.getUpperBounds()[0]);
} else if (boundGenericsType.getLowerBound() != null) {
match = classNodeType.isCompatibleWith(boundGenericsType.getLowerBound());
} else {
match = true;
}
}
}
}
} else {
match = classNodePlaceholders.getOrDefault(name, classNodeType).isCompatibleWith(redirectBoundType.getType());
}
} else {
if (redirectBoundType.isPlaceholder()) {
if (classNodeType.isPlaceholder()) {
match = classNodeType.getName().equals(redirectBoundType.getName());
} else {
GenericsTypeName name = new GenericsTypeName(redirectBoundType.getName());
if (boundPlaceHolders.containsKey(name)) {
redirectBoundType = boundPlaceHolders.get(name);
if (redirectBoundType.isPlaceholder()) {
redirectBoundType = classNodePlaceholders.getOrDefault(name, redirectBoundType);
} else if (redirectBoundType.isWildcard()) {
if (redirectBoundType.getLowerBound() != null) {
// ex: class Comparable<Integer> <=> bound Comparable<? super T>
GenericsType gt = new GenericsType(redirectBoundType.getLowerBound());
if (gt.isPlaceholder()) {
// check for recursive generic typedef, like in <T extends Comparable<? super T>>
gt = classNodePlaceholders.getOrDefault(new GenericsTypeName(gt.getName()), gt);
}
// GROOVY-6095, GROOVY-9338
if (classNodeType.isWildcard()) {
if (classNodeType.getLowerBound() != null
|| classNodeType.getUpperBounds() != null) {
match = classNodeType.checkGenerics(gt.getType());
} else {
match = false; // "?" (from Comparable<?>) does not satisfy anything
}
} else {
match = implementsInterfaceOrIsSubclassOf(gt.getType(), classNodeType.getType());
}
} else if (redirectBoundType.getUpperBounds() != null) {
// ex: class Comparable<Integer> <=> bound Comparable<? extends T & I>
for (ClassNode upperBound : redirectBoundType.getUpperBounds()) {
GenericsType gt = new GenericsType(upperBound);
if (gt.isPlaceholder()) {
// check for recursive generic typedef, like in <T extends Comparable<? super T>>
gt = classNodePlaceholders.getOrDefault(new GenericsTypeName(gt.getName()), gt);
}
// GROOVY-6095, GROOVY-9338
if (classNodeType.isWildcard()) {
if (classNodeType.getLowerBound() != null) {
match = gt.checkGenerics(classNodeType.getLowerBound());
} else if (classNodeType.getUpperBounds() != null) {
match = gt.checkGenerics(classNodeType.getUpperBounds()[0]);
} else { // GROOVY-10576: "?" vs "? extends Object" (citation required) or no match
match = (!gt.isPlaceholder() && !gt.isWildcard() && isObjectType(gt.getType()));
}
} else {
match = implementsInterfaceOrIsSubclassOf(classNodeType.getType(), gt.getType());
}
if (!match) break;
}
}
continue; // GROOVY-10010
}
}
match = redirectBoundType.isCompatibleWith(classNodeType.getType());
}
} else {
// TODO: the check for isWildcard should be replaced with a more complete check
match = redirectBoundType.isWildcard() || classNodeType.isCompatibleWith(redirectBoundType.getType());
}
}
}
return match;
}
/**
* Represents {@link GenericsType} name.
* <p>
* TODO: In order to distinguish GenericsType with same name, we should add a property to keep the declaring class.
* <ol>
* <li> change the signature of constructor GenericsTypeName to `GenericsTypeName(String name, ClassNode declaringClass)`
* <li> try to fix all compilation errors(if `GenericsType` has declaringClass property, the step would be a bit easy to fix...)
* <li> run all tests to see whether the change breaks anything
* <li> if all tests pass, congratulations! but if some tests are broken, try to debug and find why...
* </ol>
* We should find a way to set declaring class for `GenericsType` first, it can be completed at the resolving phase.
*/
public static class GenericsTypeName {
private final String name;
public GenericsTypeName(final String name) {
this.name = Objects.requireNonNull(name);
}
public String getName() {
return name;
}
@Override
public boolean equals(Object that) {
if (this == that) return true;
if (!(that instanceof GenericsTypeName)) return false;
return getName().equals(((GenericsTypeName) that).getName());
}
@Override
public int hashCode() {
return getName().hashCode();
}
@Override
public String toString() {
return getName();
}
}
}