| /* |
| * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.lang.model.util; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.LinkedHashSet; |
| |
| import javax.lang.model.AnnotatedConstruct; |
| import javax.lang.model.element.*; |
| |
| |
| /** |
| * Utility methods for operating on program elements. |
| * |
| * <p><b>Compatibility Note:</b> Methods may be added to this interface |
| * in future releases of the platform. |
| * |
| * @author Joseph D. Darcy |
| * @author Scott Seligman |
| * @author Peter von der Ahé |
| * @see javax.annotation.processing.ProcessingEnvironment#getElementUtils |
| * @since 1.6 |
| */ |
| public interface Elements { |
| |
| /** |
| * Returns a package given its fully qualified name if the package is unique in the environment. |
| * If running with modules, all modules in the modules graph are searched for matching packages. |
| * |
| * @param name fully qualified package name, or an empty string for an unnamed package |
| * @return the specified package, or {@code null} if it cannot be uniquely found |
| */ |
| PackageElement getPackageElement(CharSequence name); |
| |
| /** |
| * Returns a package given its fully qualified name, as seen from the given module. |
| * |
| * @implSpec The default implementation of this method returns |
| * {@code null}. |
| * |
| * @param name fully qualified package name, or an empty string for an unnamed package |
| * @param module module relative to which the lookup should happen |
| * @return the specified package, or {@code null} if it cannot be found |
| * @see #getAllPackageElements |
| * @since 9 |
| */ |
| default PackageElement getPackageElement(ModuleElement module, CharSequence name) { |
| return null; |
| } |
| |
| /** |
| * Returns all package elements with the given canonical name. |
| * |
| * There may be more than one package element with the same canonical |
| * name if the package elements are in different modules. |
| * |
| * @implSpec The default implementation of this method calls |
| * {@link #getAllModuleElements() getAllModuleElements} and stores |
| * the result. If the set of modules is empty, {@link |
| * #getPackageElement(CharSequence) getPackageElement(name)} is |
| * called passing through the name argument. If {@code |
| * getPackageElement(name)} is {@code null}, an empty set of |
| * package elements is returned; otherwise, a single-element set |
| * with the found package element is returned. If the set of |
| * modules is nonempty, the modules are iterated over and any |
| * non-{@code null} results of {@link |
| * #getPackageElement(ModuleElement, CharSequence) |
| * getPackageElement(module, name)} are accumulated into a |
| * set. The set is then returned. |
| * |
| * @param name the canonical name |
| * @return the package elements, or an empty set if no package with the name can be found |
| * @see #getPackageElement(ModuleElement, CharSequence) |
| * @since 9 |
| */ |
| default Set<? extends PackageElement> getAllPackageElements(CharSequence name) { |
| Set<? extends ModuleElement> modules = getAllModuleElements(); |
| if (modules.isEmpty()) { |
| PackageElement packageElt = getPackageElement(name); |
| return (packageElt != null) ? |
| Collections.singleton(packageElt): |
| Collections.emptySet(); |
| } else { |
| Set<PackageElement> result = new LinkedHashSet<>(1); // Usually expect at most 1 result |
| for (ModuleElement module: modules) { |
| PackageElement packageElt = getPackageElement(module, name); |
| if (packageElt != null) |
| result.add(packageElt); |
| } |
| return Collections.unmodifiableSet(result); |
| } |
| } |
| |
| /** |
| * Returns a type element given its canonical name if the type element is unique in the environment. |
| * If running with modules, all modules in the modules graph are searched for matching |
| * type elements. |
| * |
| * @param name the canonical name |
| * @return the named type element, or {@code null} if it cannot be uniquely found |
| */ |
| TypeElement getTypeElement(CharSequence name); |
| |
| /** |
| * Returns a type element given its canonical name, as seen from the given module. |
| * |
| * @implSpec The default implementation of this method returns |
| * {@code null}. |
| * |
| * @param name the canonical name |
| * @param module module relative to which the lookup should happen |
| * @return the named type element, or {@code null} if it cannot be found |
| * @see #getAllTypeElements |
| * @since 9 |
| */ |
| default TypeElement getTypeElement(ModuleElement module, CharSequence name) { |
| return null; |
| } |
| |
| /** |
| * Returns all type elements with the given canonical name. |
| * |
| * There may be more than one type element with the same canonical |
| * name if the type elements are in different modules. |
| * |
| * @implSpec The default implementation of this method calls |
| * {@link #getAllModuleElements() getAllModuleElements} and stores |
| * the result. If the set of modules is empty, {@link |
| * #getTypeElement(CharSequence) getTypeElement(name)} is called |
| * passing through the name argument. If {@code |
| * getTypeElement(name)} is {@code null}, an empty set of type |
| * elements is returned; otherwise, a single-element set with the |
| * found type element is returned. If the set of modules is |
| * nonempty, the modules are iterated over and any non-{@code null} |
| * results of {@link #getTypeElement(ModuleElement, |
| * CharSequence) getTypeElement(module, name)} are accumulated |
| * into a set. The set is then returned. |
| * |
| * @param name the canonical name |
| * @return the type elements, or an empty set if no type with the name can be found |
| * @see #getTypeElement(ModuleElement, CharSequence) |
| * @since 9 |
| */ |
| default Set<? extends TypeElement> getAllTypeElements(CharSequence name) { |
| Set<? extends ModuleElement> modules = getAllModuleElements(); |
| if (modules.isEmpty()) { |
| TypeElement typeElt = getTypeElement(name); |
| return (typeElt != null) ? |
| Collections.singleton(typeElt): |
| Collections.emptySet(); |
| } else { |
| Set<TypeElement> result = new LinkedHashSet<>(1); // Usually expect at most 1 result |
| for (ModuleElement module: modules) { |
| TypeElement typeElt = getTypeElement(module, name); |
| if (typeElt != null) |
| result.add(typeElt); |
| } |
| return Collections.unmodifiableSet(result); |
| } |
| } |
| |
| /** |
| * Returns a module element given its fully qualified name. |
| * |
| * If the named module cannot be found, {@code null} is |
| * returned. One situation where a module cannot be found is if |
| * the environment does not include modules, such as an annotation |
| * processing environment configured for a {@linkplain |
| * javax.annotation.processing.ProcessingEnvironment#getSourceVersion |
| * source version} without modules. |
| * |
| * @implSpec The default implementation of this method returns |
| * {@code null}. |
| * |
| * @param name the name |
| * @return the named module element, or {@code null} if it cannot be found |
| * @see #getAllModuleElements |
| * @since 9 |
| * @spec JPMS |
| */ |
| default ModuleElement getModuleElement(CharSequence name) { |
| return null; |
| } |
| |
| /** |
| * Returns all module elements in the current environment. |
| * |
| * If no modules are present, an empty set is returned. One |
| * situation where no modules are present occurs when the |
| * environment does not include modules, such as an annotation |
| * processing environment configured for a {@linkplain |
| * javax.annotation.processing.ProcessingEnvironment#getSourceVersion |
| * source version} without modules. |
| * |
| * @implSpec The default implementation of this method returns |
| * an empty set. |
| * |
| * @return the known module elements, or an empty set if there are no modules |
| * @see #getModuleElement(CharSequence) |
| * @since 9 |
| */ |
| default Set<? extends ModuleElement> getAllModuleElements() { |
| return Collections.emptySet(); |
| } |
| |
| /** |
| * Returns the values of an annotation's elements, including defaults. |
| * |
| * @see AnnotationMirror#getElementValues() |
| * @param a annotation to examine |
| * @return the values of the annotation's elements, including defaults |
| */ |
| Map<? extends ExecutableElement, ? extends AnnotationValue> |
| getElementValuesWithDefaults(AnnotationMirror a); |
| |
| /** |
| * Returns the text of the documentation ("Javadoc") |
| * comment of an element. |
| * |
| * <p> A documentation comment of an element is a comment that |
| * begins with "{@code /**}" , ends with a separate |
| * "<code>*/</code>", and immediately precedes the element, |
| * ignoring white space. Therefore, a documentation comment |
| * contains at least three"{@code *}" characters. The text |
| * returned for the documentation comment is a processed form of |
| * the comment as it appears in source code. The leading "{@code |
| * /**}" and trailing "<code>*/</code>" are removed. For lines |
| * of the comment starting after the initial "{@code /**}", |
| * leading white space characters are discarded as are any |
| * consecutive "{@code *}" characters appearing after the white |
| * space or starting the line. The processed lines are then |
| * concatenated together (including line terminators) and |
| * returned. |
| * |
| * @param e the element being examined |
| * @return the documentation comment of the element, or {@code null} |
| * if there is none |
| * @jls 3.6 White Space |
| */ |
| String getDocComment(Element e); |
| |
| /** |
| * Returns {@code true} if the element is deprecated, {@code false} otherwise. |
| * |
| * @param e the element being examined |
| * @return {@code true} if the element is deprecated, {@code false} otherwise |
| */ |
| boolean isDeprecated(Element e); |
| |
| /** |
| * Returns the <em>origin</em> of the given element. |
| * |
| * <p>Note that if this method returns {@link Origin#EXPLICIT |
| * EXPLICIT} and the element was created from a class file, then |
| * the element may not, in fact, correspond to an explicitly |
| * declared construct in source code. This is due to limitations |
| * of the fidelity of the class file format in preserving |
| * information from source code. For example, at least some |
| * versions of the class file format do not preserve whether a |
| * constructor was explicitly declared by the programmer or was |
| * implicitly declared as the <em>default constructor</em>. |
| * |
| * @implSpec The default implementation of this method returns |
| * {@link Origin#EXPLICIT EXPLICIT}. |
| * |
| * @param e the element being examined |
| * @return the origin of the given element |
| * @since 9 |
| */ |
| default Origin getOrigin(Element e) { |
| return Origin.EXPLICIT; |
| } |
| |
| /** |
| * Returns the <em>origin</em> of the given annotation mirror. |
| * |
| * An annotation mirror is {@linkplain Origin#MANDATED mandated} |
| * if it is an implicitly declared <em>container annotation</em> |
| * used to hold repeated annotations of a repeatable annotation |
| * type. |
| * |
| * <p>Note that if this method returns {@link Origin#EXPLICIT |
| * EXPLICIT} and the annotation mirror was created from a class |
| * file, then the element may not, in fact, correspond to an |
| * explicitly declared construct in source code. This is due to |
| * limitations of the fidelity of the class file format in |
| * preserving information from source code. For example, at least |
| * some versions of the class file format do not preserve whether |
| * an annotation was explicitly declared by the programmer or was |
| * implicitly declared as a <em>container annotation</em>. |
| * |
| * @implSpec The default implementation of this method returns |
| * {@link Origin#EXPLICIT EXPLICIT}. |
| * |
| * @param c the construct the annotation mirror modifies |
| * @param a the annotation mirror being examined |
| * @return the origin of the given annotation mirror |
| * @jls 9.6.3 Repeatable Annotation Types |
| * @jls 9.7.5 Multiple Annotations of the Same Type |
| * @since 9 |
| */ |
| default Origin getOrigin(AnnotatedConstruct c, |
| AnnotationMirror a) { |
| return Origin.EXPLICIT; |
| } |
| |
| /** |
| * Returns the <em>origin</em> of the given module directive. |
| * |
| * <p>Note that if this method returns {@link Origin#EXPLICIT |
| * EXPLICIT} and the module directive was created from a class |
| * file, then the module directive may not, in fact, correspond to |
| * an explicitly declared construct in source code. This is due to |
| * limitations of the fidelity of the class file format in |
| * preserving information from source code. For example, at least |
| * some versions of the class file format do not preserve whether |
| * a {@code uses} directive was explicitly declared by the |
| * programmer or was added as a synthetic construct. |
| * |
| * <p>Note that an implementation may not be able to reliably |
| * determine the origin status of the directive if the directive |
| * is created from a class file due to limitations of the fidelity |
| * of the class file format in preserving information from source |
| * code. |
| * |
| * @implSpec The default implementation of this method returns |
| * {@link Origin#EXPLICIT EXPLICIT}. |
| * |
| * @param m the module of the directive |
| * @param directive the module directive being examined |
| * @return the origin of the given directive |
| * @since 9 |
| */ |
| default Origin getOrigin(ModuleElement m, |
| ModuleElement.Directive directive) { |
| return Origin.EXPLICIT; |
| } |
| |
| /** |
| * The <em>origin</em> of an element or other language model |
| * item. The origin of an element or item models how a construct |
| * in a program is declared in the source code, explicitly, |
| * implicitly, etc. |
| * |
| * <p>Note that it is possible additional kinds of origin values |
| * will be added in future versions of the platform. |
| * |
| * @jls 13.1 The Form of a Binary |
| * @since 9 |
| */ |
| public enum Origin { |
| /** |
| * Describes a construct explicitly declared in source code. |
| */ |
| EXPLICIT, |
| |
| /** |
| * A mandated construct is one that is not explicitly declared |
| * in the source code, but whose presence is mandated by the |
| * specification. Such a construct is said to be implicitly |
| * declared. |
| * |
| * One example of a mandated element is a <em>default |
| * constructor</em> in a class that contains no explicit |
| * constructor declarations. |
| * |
| * Another example of a mandated construct is an implicitly |
| * declared <em>container annotation</em> used to hold |
| * multiple annotations of a repeatable annotation type. |
| * |
| * @jls 8.8.9 Default Constructor |
| * @jls 8.9.3 Enum Members |
| * @jls 9.6.3 Repeatable Annotation Types |
| * @jls 9.7.5 Multiple Annotations of the Same Type |
| */ |
| MANDATED, |
| |
| /** |
| * A synthetic construct is one that is neither implicitly nor |
| * explicitly declared in the source code. Such a construct is |
| * typically a translation artifact created by a compiler. |
| */ |
| SYNTHETIC; |
| |
| /** |
| * Returns {@code true} for values corresponding to constructs |
| * that are implicitly or explicitly declared, {@code false} |
| * otherwise. |
| * @return {@code true} for {@link EXPLICIT} and {@link |
| * MANDATED}, {@code false} otherwise. |
| */ |
| public boolean isDeclared() { |
| return this != SYNTHETIC; |
| } |
| } |
| |
| /** |
| * Returns {@code true} if the executable element is a bridge |
| * method, {@code false} otherwise. |
| * |
| * @implSpec The default implementation of this method returns {@code false}. |
| * |
| * @param e the executable being examined |
| * @return {@code true} if the executable element is a bridge |
| * method, {@code false} otherwise |
| * @since 9 |
| */ |
| default boolean isBridge(ExecutableElement e) { |
| return false; |
| } |
| |
| /** |
| * Returns the <i>binary name</i> of a type element. |
| * |
| * @param type the type element being examined |
| * @return the binary name |
| * |
| * @see TypeElement#getQualifiedName |
| * @jls 13.1 The Form of a Binary |
| */ |
| Name getBinaryName(TypeElement type); |
| |
| |
| /** |
| * Returns the package of an element. The package of a package is |
| * itself. |
| * |
| * @param type the element being examined |
| * @return the package of an element |
| */ |
| PackageElement getPackageOf(Element type); |
| |
| /** |
| * Returns the module of an element. The module of a module is |
| * itself. |
| * If there is no module for the element, null is returned. One situation where there is |
| * no module for an element is if the environment does not include modules, such as |
| * an annotation processing environment configured for |
| * a {@linkplain |
| * javax.annotation.processing.ProcessingEnvironment#getSourceVersion |
| * source version} without modules. |
| * |
| * @implSpec The default implementation of this method returns |
| * {@code null}. |
| * |
| * @param type the element being examined |
| * @return the module of an element |
| * @since 9 |
| * @spec JPMS |
| */ |
| default ModuleElement getModuleOf(Element type) { |
| return null; |
| } |
| |
| /** |
| * Returns all members of a type element, whether inherited or |
| * declared directly. For a class the result also includes its |
| * constructors, but not local or anonymous classes. |
| * |
| * @apiNote Elements of certain kinds can be isolated using |
| * methods in {@link ElementFilter}. |
| * |
| * @param type the type being examined |
| * @return all members of the type |
| * @see Element#getEnclosedElements |
| */ |
| List<? extends Element> getAllMembers(TypeElement type); |
| |
| /** |
| * Returns all annotations <i>present</i> on an element, whether |
| * directly present or present via inheritance. |
| * |
| * @param e the element being examined |
| * @return all annotations of the element |
| * @see Element#getAnnotationMirrors |
| * @see javax.lang.model.AnnotatedConstruct |
| */ |
| List<? extends AnnotationMirror> getAllAnnotationMirrors(Element e); |
| |
| /** |
| * Tests whether one type, method, or field hides another. |
| * |
| * @param hider the first element |
| * @param hidden the second element |
| * @return {@code true} if and only if the first element hides |
| * the second |
| */ |
| boolean hides(Element hider, Element hidden); |
| |
| /** |
| * Tests whether one method, as a member of a given type, |
| * overrides another method. |
| * When a non-abstract method overrides an abstract one, the |
| * former is also said to <i>implement</i> the latter. |
| * |
| * <p> In the simplest and most typical usage, the value of the |
| * {@code type} parameter will simply be the class or interface |
| * directly enclosing {@code overrider} (the possibly-overriding |
| * method). For example, suppose {@code m1} represents the method |
| * {@code String.hashCode} and {@code m2} represents {@code |
| * Object.hashCode}. We can then ask whether {@code m1} overrides |
| * {@code m2} within the class {@code String} (it does): |
| * |
| * <blockquote> |
| * {@code assert elements.overrides(m1, m2, |
| * elements.getTypeElement("java.lang.String")); } |
| * </blockquote> |
| * |
| * A more interesting case can be illustrated by the following example |
| * in which a method in type {@code A} does not override a |
| * like-named method in type {@code B}: |
| * |
| * <blockquote> |
| * {@code class A { public void m() {} } }<br> |
| * {@code interface B { void m(); } }<br> |
| * ...<br> |
| * {@code m1 = ...; // A.m }<br> |
| * {@code m2 = ...; // B.m }<br> |
| * {@code assert ! elements.overrides(m1, m2, |
| * elements.getTypeElement("A")); } |
| * </blockquote> |
| * |
| * When viewed as a member of a third type {@code C}, however, |
| * the method in {@code A} does override the one in {@code B}: |
| * |
| * <blockquote> |
| * {@code class C extends A implements B {} }<br> |
| * ...<br> |
| * {@code assert elements.overrides(m1, m2, |
| * elements.getTypeElement("C")); } |
| * </blockquote> |
| * |
| * @param overrider the first method, possible overrider |
| * @param overridden the second method, possibly being overridden |
| * @param type the type of which the first method is a member |
| * @return {@code true} if and only if the first method overrides |
| * the second |
| * @jls 8.4.8 Inheritance, Overriding, and Hiding |
| * @jls 9.4.1 Inheritance and Overriding |
| */ |
| boolean overrides(ExecutableElement overrider, ExecutableElement overridden, |
| TypeElement type); |
| |
| /** |
| * Returns the text of a <i>constant expression</i> representing a |
| * primitive value or a string. |
| * The text returned is in a form suitable for representing the value |
| * in source code. |
| * |
| * @param value a primitive value or string |
| * @return the text of a constant expression |
| * @throws IllegalArgumentException if the argument is not a primitive |
| * value or string |
| * |
| * @see VariableElement#getConstantValue() |
| */ |
| String getConstantExpression(Object value); |
| |
| /** |
| * Prints a representation of the elements to the given writer in |
| * the specified order. The main purpose of this method is for |
| * diagnostics. The exact format of the output is <em>not</em> |
| * specified and is subject to change. |
| * |
| * @param w the writer to print the output to |
| * @param elements the elements to print |
| */ |
| void printElements(java.io.Writer w, Element... elements); |
| |
| /** |
| * Return a name with the same sequence of characters as the |
| * argument. |
| * |
| * @param cs the character sequence to return as a name |
| * @return a name with the same sequence of characters as the argument |
| */ |
| Name getName(CharSequence cs); |
| |
| /** |
| * Returns {@code true} if the type element is a functional interface, {@code false} otherwise. |
| * |
| * @param type the type element being examined |
| * @return {@code true} if the element is a functional interface, {@code false} otherwise |
| * @jls 9.8 Functional Interfaces |
| * @since 1.8 |
| */ |
| boolean isFunctionalInterface(TypeElement type); |
| } |
