jdk8-mips64-public/langtools: src/share/classes/javax/annotation/processing/Processor.java@c75be5bc5283 (annotated)

src/share/classes/javax/annotation/processing/Processor.java@c75be5bc5283 (annotated)

src/share/classes/javax/annotation/processing/Processor.java

Tue, 09 Oct 2012 19:10:00 -0700

author: jjg
date: Tue, 09 Oct 2012 19:10:00 -0700
changeset 1357: c75be5bc5283
parent 972: 694ff82ca68e
child 1876: 1908e86ee49a
permissions: -rw-r--r--

8000663: clean up langtools imports
Reviewed-by: darcy

 /*
  * Copyright (c) 2005, 2006, 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.annotation.processing;
 import java.util.Set;
 import javax.lang.model.element.*;
 import javax.lang.model.SourceVersion;
 /**
  * The interface for an annotation processor.
  *
  * <p>Annotation processing happens in a sequence of {@linkplain
  * javax.annotation.processing.RoundEnvironment rounds}.  On each
  * round, a processor may be asked to {@linkplain #process process} a
  * subset of the annotations found on the source and class files
  * produced by a prior round.  The inputs to the first round of
  * processing are the initial inputs to a run of the tool; these
  * initial inputs can be regarded as the output of a virtual zeroth
  * round of processing.  If a processor was asked to process on a
  * given round, it will be asked to process on subsequent rounds,
  * including the last round, even if there are no annotations for it
  * to process.  The tool infrastructure may also ask a processor to
  * process files generated implicitly by the tool's operation.
  *
  * <p> Each implementation of a {@code Processor} must provide a
  * public no-argument constructor to be used by tools to instantiate
  * the processor.  The tool infrastructure will interact with classes
  * implementing this interface as follows:
  *
  * <ol>
  *
  * <li>If an existing {@code Processor} object is not being used, to
  * create an instance of a processor the tool calls the no-arg
  * constructor of the processor class.
  *
  * <li>Next, the tool calls the {@link #init init} method with
  * an appropriate {@code ProcessingEnvironment}.
  *
  * <li>Afterwards, the tool calls {@link #getSupportedAnnotationTypes
  * getSupportedAnnotationTypes}, {@link #getSupportedOptions
  * getSupportedOptions}, and {@link #getSupportedSourceVersion
  * getSupportedSourceVersion}.  These methods are only called once per
  * run, not on each round.
  *
  * <li>As appropriate, the tool calls the {@link #process process}
  * method on the {@code Processor} object; a new {@code Processor}
  * object is <em>not</em> created for each round.
  *
  * </ol>
  *
  * If a processor object is created and used without the above
  * protocol being followed, then the processor's behavior is not
  * defined by this interface specification.
  *
  * <p> The tool uses a <i>discovery process</i> to find annotation
  * processors and decide whether or not they should be run.  By
  * configuring the tool, the set of potential processors can be
  * controlled.  For example, for a {@link javax.tools.JavaCompiler
  * JavaCompiler} the list of candidate processors to run can be
  * {@linkplain javax.tools.JavaCompiler.CompilationTask#setProcessors
  * set directly} or controlled by a {@linkplain
  * javax.tools.StandardLocation#ANNOTATION_PROCESSOR_PATH search path}
  * used for a {@linkplain java.util.ServiceLoader service-style}
  * lookup.  Other tool implementations may have different
  * configuration mechanisms, such as command line options; for
  * details, refer to the particular tool's documentation.  Which
  * processors the tool asks to {@linkplain #process run} is a function
  * of what annotations are present on the {@linkplain
  * RoundEnvironment#getRootElements root elements}, what {@linkplain
  * #getSupportedAnnotationTypes annotation types a processor
  * processes}, and whether or not a processor {@linkplain #process
  * claims the annotations it processes}.  A processor will be asked to
  * process a subset of the annotation types it supports, possibly an
  * empty set.
  *
  * For a given round, the tool computes the set of annotation types on
  * the root elements.  If there is at least one annotation type
  * present, as processors claim annotation types, they are removed
  * from the set of unmatched annotations.  When the set is empty or no
  * more processors are available, the round has run to completion.  If
  * there are no annotation types present, annotation processing still
  * occurs but only <i>universal processors</i> which support
  * processing {@code "*"} can claim the (empty) set of annotation
  * types.
  *
  * <p>Note that if a processor supports {@code "*"} and returns {@code
  * true}, all annotations are claimed.  Therefore, a universal
  * processor being used to, for example, implement additional validity
  * checks should return {@code false} so as to not prevent other such
  * checkers from being able to run.
  *
  * <p>If a processor throws an uncaught exception, the tool may cease
  * other active annotation processors.  If a processor raises an
  * error, the current round will run to completion and the subsequent
  * round will indicate an {@linkplain RoundEnvironment#errorRaised
  * error was raised}.  Since annotation processors are run in a
  * cooperative environment, a processor should throw an uncaught
  * exception only in situations where no error recovery or reporting
  * is feasible.
  *
  * <p>The tool environment is not required to support annotation
  * processors that access environmental resources, either {@linkplain
  * RoundEnvironment per round} or {@linkplain ProcessingEnvironment
  * cross-round}, in a multi-threaded fashion.
  *
  * <p>If the methods that return configuration information about the
  * annotation processor return {@code null}, return other invalid
  * input, or throw an exception, the tool infrastructure must treat
  * this as an error condition.
  *
  * <p>To be robust when running in different tool implementations, an
  * annotation processor should have the following properties:
  *
  * <ol>
  *
  * <li>The result of processing a given input is not a function of the presence or absence
  * of other inputs (orthogonality).
  *
  * <li>Processing the same input produces the same output (consistency).
  *
  * <li>Processing input <i>A</i> followed by processing input <i>B</i>
  * is equivalent to processing <i>B</i> then <i>A</i>
  * (commutativity)
  *
  * <li>Processing an input does not rely on the presence of the output
  * of other annotation processors (independence)
  *
  * </ol>
  *
  * <p>The {@link Filer} interface discusses restrictions on how
  * processors can operate on files.
  *
  * <p>Note that implementors of this interface may find it convenient
  * to extend {@link AbstractProcessor} rather than implementing this
  * interface directly.
  *
  * @author Joseph D. Darcy
  * @author Scott Seligman
  * @author Peter von der Ah&eacute;
  * @since 1.6
  */
 public interface Processor {
     /**
      * Returns the options recognized by this processor.  An
      * implementation of the processing tool must provide a way to
      * pass processor-specific options distinctly from options passed
      * to the tool itself, see {@link ProcessingEnvironment#getOptions
      * getOptions}.
      *
      * <p>Each string returned in the set must be a period separated
      * sequence of {@linkplain
      * javax.lang.model.SourceVersion#isIdentifier identifiers}:
      *
      * <blockquote>
      * <dl>
      * <dt><i>SupportedOptionString:</i>
      * <dd><i>Identifiers</i>
      * <p>
      * <dt><i>Identifiers:</i>
      * <dd> <i>Identifier</i>
      * <dd> <i>Identifier</i> {@code .} <i>Identifiers</i>
      * <p>
      * <dt><i>Identifier:</i>
      * <dd>Syntactic identifier, including keywords and literals
      * </dl>
      * </blockquote>
      *
      * <p> A tool might use this information to determine if any
      * options provided by a user are unrecognized by any processor,
      * in which case it may wish to report a warning.
      *
      * @return the options recognized by this processor or an
      *         empty collection if none
      * @see javax.annotation.processing.SupportedOptions
      */
     Set<String> getSupportedOptions();
     /**
      * Returns the names of the annotation types supported by this
      * processor.  An element of the result may be the canonical
      * (fully qualified) name of a supported annotation type.
      * Alternately it may be of the form &quot;<tt><i>name</i>.*</tt>&quot;
      * representing the set of all annotation types with canonical
      * names beginning with &quot;<tt><i>name.</i></tt>&quot;.  Finally, {@code
      * "*"} by itself represents the set of all annotation types,
      * including the empty set.  Note that a processor should not
      * claim {@code "*"} unless it is actually processing all files;
      * claiming unnecessary annotations may cause a performance
      * slowdown in some environments.
      *
      * <p>Each string returned in the set must be accepted by the
      * following grammar:
      *
      * <blockquote>
      * <dl>
      * <dt><i>SupportedAnnotationTypeString:</i>
      * <dd><i>TypeName</i> <i>DotStar</i><sub><i>opt</i></sub>
      * <dd><tt>*</tt>
      * <p>
      * <dt><i>DotStar:</i>
      * <dd><tt>.</tt> <tt>*</tt>
      * </dl>
      * </blockquote>
      *
      * where <i>TypeName</i> is as defined in
      * <cite>The Java&trade; Language Specification</cite>.
      *
      * @return the names of the annotation types supported by this processor
      * @see javax.annotation.processing.SupportedAnnotationTypes
      * @jls 3.8 Identifiers
      * @jls 6.5.5 Meaning of Type Names
      */
     Set<String> getSupportedAnnotationTypes();
     /**
      * Returns the latest source version supported by this annotation
      * processor.
      *
      * @return the latest source version supported by this annotation
      * processor.
      * @see javax.annotation.processing.SupportedSourceVersion
      * @see ProcessingEnvironment#getSourceVersion
      */
     SourceVersion getSupportedSourceVersion();
     /**
      * Initializes the processor with the processing environment.
      *
      * @param processingEnv environment for facilities the tool framework
      * provides to the processor
      */
     void init(ProcessingEnvironment processingEnv);
     /**
      * Processes a set of annotation types on type elements
      * originating from the prior round and returns whether or not
      * these annotations are claimed by this processor.  If {@code
      * true} is returned, the annotations are claimed and subsequent
      * processors will not be asked to process them; if {@code false}
      * is returned, the annotations are unclaimed and subsequent
      * processors may be asked to process them.  A processor may
      * always return the same boolean value or may vary the result
      * based on chosen criteria.
      *
      * <p>The input set will be empty if the processor supports {@code
      * "*"} and the root elements have no annotations.  A {@code
      * Processor} must gracefully handle an empty set of annotations.
      *
      * @param annotations the annotation types requested to be processed
      * @param roundEnv  environment for information about the current and prior round
      * @return whether or not the set of annotations are claimed by this processor
      */
     boolean process(Set<? extends TypeElement> annotations,
                     RoundEnvironment roundEnv);
    /**
     * Returns to the tool infrastructure an iterable of suggested
     * completions to an annotation.  Since completions are being asked
     * for, the information provided about the annotation may be
     * incomplete, as if for a source code fragment. A processor may
     * return an empty iterable.  Annotation processors should focus
     * their efforts on providing completions for annotation members
     * with additional validity constraints known to the processor, for
     * example an {@code int} member whose value should lie between 1
     * and 10 or a string member that should be recognized by a known
     * grammar, such as a regular expression or a URL.
     *
     * <p>Since incomplete programs are being modeled, some of the
     * parameters may only have partial information or may be {@code
     * null}.  At least one of {@code element} and {@code userText}
     * must be non-{@code null}.  If {@code element} is non-{@code
     * null}, {@code annotation} and {@code member} may be {@code
     * null}.  Processors may not throw a {@code NullPointerException}
     * if some parameters are {@code null}; if a processor has no
     * completions to offer based on the provided information, an
     * empty iterable can be returned.  The processor may also return
     * a single completion with an empty value string and a message
     * describing why there are no completions.
     *
     * <p>Completions are informative and may reflect additional
     * validity checks performed by annotation processors.  For
     * example, consider the simple annotation:
     *
     * <blockquote>
     * <pre>
     * &#064;MersennePrime {
     *    int value();
     * }
     * </pre>
     * </blockquote>
     *
     * (A Mersenne prime is prime number of the form
     * 2<sup><i>n</i></sup> - 1.) Given an {@code AnnotationMirror}
     * for this annotation type, a list of all such primes in the
     * {@code int} range could be returned without examining any other
     * arguments to {@code getCompletions}:
     *
     * <blockquote>
     * <pre>
     * import static javax.annotation.processing.Completions.*;
     * ...
     * return Arrays.asList({@link Completions#of(String) of}(&quot;3&quot;),
     *                      of(&quot;7&quot;),
     *                      of(&quot;31&quot;),
     *                      of(&quot;127&quot;),
     *                      of(&quot;8191&quot;),
     *                      of(&quot;131071&quot;),
     *                      of(&quot;524287&quot;),
     *                      of(&quot;2147483647&quot;));
     * </pre>
     * </blockquote>
     *
     * A more informative set of completions would include the number
     * of each prime:
     *
     * <blockquote>
     * <pre>
     * return Arrays.asList({@link Completions#of(String, String) of}(&quot;3&quot;,          &quot;M2&quot;),
     *                      of(&quot;7&quot;,          &quot;M3&quot;),
     *                      of(&quot;31&quot;,         &quot;M5&quot;),
     *                      of(&quot;127&quot;,        &quot;M7&quot;),
     *                      of(&quot;8191&quot;,       &quot;M13&quot;),
     *                      of(&quot;131071&quot;,     &quot;M17&quot;),
     *                      of(&quot;524287&quot;,     &quot;M19&quot;),
     *                      of(&quot;2147483647&quot;, &quot;M31&quot;));
     * </pre>
     * </blockquote>
     *
     * However, if the {@code userText} is available, it can be checked
     * to see if only a subset of the Mersenne primes are valid.  For
     * example, if the user has typed
     *
     * <blockquote>
     * <code>
     * &#064;MersennePrime(1
     * </code>
     * </blockquote>
     *
     * the value of {@code userText} will be {@code "1"}; and only
     * two of the primes are possible completions:
     *
     * <blockquote>
     * <pre>
     * return Arrays.asList(of(&quot;127&quot;,        &quot;M7&quot;),
     *                      of(&quot;131071&quot;,     &quot;M17&quot;));
     * </pre>
     * </blockquote>
     *
     * Sometimes no valid completion is possible.  For example, there
     * is no in-range Mersenne prime starting with 9:
     *
     * <blockquote>
     * <code>
     * &#064;MersennePrime(9
     * </code>
     * </blockquote>
     *
     * An appropriate response in this case is to either return an
     * empty list of completions,
     *
     * <blockquote>
     * <pre>
     * return Collections.emptyList();
     * </pre>
     * </blockquote>
     *
     * or a single empty completion with a helpful message
     *
     * <blockquote>
     * <pre>
     * return Arrays.asList(of(&quot;&quot;, &quot;No in-range Mersenne primes start with 9&quot;));
     * </pre>
     * </blockquote>
     *
     * @param element the element being annotated
     * @param annotation the (perhaps partial) annotation being
     *                   applied to the element
     * @param member the annotation member to return possible completions for
     * @param userText source code text to be completed
     *
     * @return suggested completions to the annotation
     */
     Iterable<? extends Completion> getCompletions(Element element,
                                                   AnnotationMirror annotation,
                                                   ExecutableElement member,
                                                   String userText);
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/javax/annotation/processing/Processor.java@c75be5bc5283 (annotated)

src/share/classes/javax/annotation/processing/Processor.java