/*
* Copyright (c) 2005, 2016, 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.tools;
import java.io.File;
import java.io.Writer;
import java.nio.charset.Charset;
import java.util.Locale;
import java.util.concurrent.Callable;
import javax.annotation.processing.Processor;
/**
* Interface to invoke Java™ programming language compilers from
* programs.
*
* <p>The compiler might generate diagnostics during compilation (for
* example, error messages). If a diagnostic listener is provided,
* the diagnostics will be supplied to the listener. If no listener
* is provided, the diagnostics will be formatted in an unspecified
* format and written to the default output, which is {@code
* System.err} unless otherwise specified. Even if a diagnostic
* listener is supplied, some diagnostics might not fit in a {@code
* Diagnostic} and will be written to the default output.
*
* <p>A compiler tool has an associated standard file manager, which
* is the file manager that is native to the tool (or built-in). The
* standard file manager can be obtained by calling {@linkplain
* #getStandardFileManager getStandardFileManager}.
*
* <p>A compiler tool must function with any file manager as long as
* any additional requirements as detailed in the methods below are
* met. If no file manager is provided, the compiler tool will use a
* standard file manager such as the one returned by {@linkplain
* #getStandardFileManager getStandardFileManager}.
*
* <p>An instance implementing this interface must conform to
* <cite>The Java™ Language Specification</cite>
* and generate class files conforming to
* <cite>The Java™ Virtual Machine Specification</cite>.
* The versions of these
* specifications are defined in the {@linkplain Tool} interface.
*
* Additionally, an instance of this interface supporting {@link
* javax.lang.model.SourceVersion#RELEASE_6 SourceVersion.RELEASE_6}
* or higher must also support {@linkplain javax.annotation.processing
* annotation processing}.
*
* <p>The compiler relies on two services: {@linkplain
* DiagnosticListener diagnostic listener} and {@linkplain
* JavaFileManager file manager}. Although most classes and
* interfaces in this package defines an API for compilers (and
* tools in general) the interfaces {@linkplain DiagnosticListener},
* {@linkplain JavaFileManager}, {@linkplain FileObject}, and
* {@linkplain JavaFileObject} are not intended to be used in
* applications. Instead these interfaces are intended to be
* implemented and used to provide customized services for a
* compiler and thus defines an SPI for compilers.
*
* <p>There are a number of classes and interfaces in this package
* which are designed to ease the implementation of the SPI to
* customize the behavior of a compiler:
*
* <dl>
* <dt>{@link StandardJavaFileManager}</dt>
* <dd>
*
* Every compiler which implements this interface provides a
* standard file manager for operating on regular {@linkplain
* java.io.File files}. The StandardJavaFileManager interface
* defines additional methods for creating file objects from
* regular files.
*
* <p>The standard file manager serves two purposes:
*
* <ul>
* <li>basic building block for customizing how a compiler reads
* and writes files</li>
* <li>sharing between multiple compilation tasks</li>
* </ul>
*
* <p>Reusing a file manager can potentially reduce overhead of
* scanning the file system and reading jar files. Although there
* might be no reduction in overhead, a standard file manager must
* work with multiple sequential compilations making the following
* example a recommended coding pattern:
*
* <pre>
* File[] files1 = ... ; // input for first compilation task
* File[] files2 = ... ; // input for second compilation task
*
* JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
* StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null);
*
* {@code Iterable<? extends JavaFileObject>} compilationUnits1 =
* fileManager.getJavaFileObjectsFromFiles({@linkplain java.util.Arrays#asList Arrays.asList}(files1));
* compiler.getTask(null, fileManager, null, null, null, compilationUnits1).call();
*
* {@code Iterable<? extends JavaFileObject>} compilationUnits2 =
* fileManager.getJavaFileObjects(files2); // use alternative method
* // reuse the same file manager to allow caching of jar files
* compiler.getTask(null, fileManager, null, null, null, compilationUnits2).call();
*
* fileManager.close();</pre>
*
* </dd>
*
* <dt>{@link DiagnosticCollector}</dt>
* <dd>
* Used to collect diagnostics in a list, for example:
* <pre>
* {@code Iterable<? extends JavaFileObject>} compilationUnits = ...;
* JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
* {@code DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<JavaFileObject>();}
* StandardJavaFileManager fileManager = compiler.getStandardFileManager(diagnostics, null, null);
* compiler.getTask(null, fileManager, diagnostics, null, null, compilationUnits).call();
*
* for ({@code Diagnostic<? extends JavaFileObject>} diagnostic : diagnostics.getDiagnostics())
* System.out.format("Error on line %d in %s%n",
* diagnostic.getLineNumber(),
* diagnostic.getSource().toUri());
*
* fileManager.close();</pre>
* </dd>
*
* <dt>
* {@link ForwardingJavaFileManager}, {@link ForwardingFileObject}, and
* {@link ForwardingJavaFileObject}
* </dt>
* <dd>
*
* Subclassing is not available for overriding the behavior of a
* standard file manager as it is created by calling a method on a
* compiler, not by invoking a constructor. Instead forwarding
* (or delegation) should be used. These classes makes it easy to
* forward most calls to a given file manager or file object while
* allowing customizing behavior. For example, consider how to
* log all calls to {@linkplain JavaFileManager#flush}:
*
* <pre>
* final Logger logger = ...;
* {@code Iterable<? extends JavaFileObject>} compilationUnits = ...;
* JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
* StandardJavaFileManager stdFileManager = compiler.getStandardFileManager(null, null, null);
* JavaFileManager fileManager = new ForwardingJavaFileManager(stdFileManager) {
* public void flush() throws IOException {
* logger.entering(StandardJavaFileManager.class.getName(), "flush");
* super.flush();
* logger.exiting(StandardJavaFileManager.class.getName(), "flush");
* }
* };
* compiler.getTask(null, fileManager, null, null, null, compilationUnits).call();</pre>
* </dd>
*
* <dt>{@link SimpleJavaFileObject}</dt>
* <dd>
*
* This class provides a basic file object implementation which
* can be used as building block for creating file objects. For
* example, here is how to define a file object which represent
* source code stored in a string:
*
* <pre>
* /**
* * A file object used to represent source coming from a string.
* {@code *}/
* public class JavaSourceFromString extends SimpleJavaFileObject {
* /**
* * The source code of this "file".
* {@code *}/
* final String code;
*
* /**
* * Constructs a new JavaSourceFromString.
* * {@code @}param name the name of the compilation unit represented by this file object
* * {@code @}param code the source code for the compilation unit represented by this file object
* {@code *}/
* JavaSourceFromString(String name, String code) {
* super({@linkplain java.net.URI#create URI.create}("string:///" + name.replace('.','/') + Kind.SOURCE.extension),
* Kind.SOURCE);
* this.code = code;
* }
*
* {@code @}Override
* public CharSequence getCharContent(boolean ignoreEncodingErrors) {
* return code;
* }
* }</pre>
* </dd>
* </dl>
*
* @author Peter von der Ahé
* @author Jonathan Gibbons
* @see DiagnosticListener
* @see Diagnostic
* @see JavaFileManager
* @since 1.6
*/
public interface JavaCompiler extends Tool, OptionChecker {
/**
* Creates a future for a compilation task with the given
* components and arguments. The compilation might not have
* completed as described in the CompilationTask interface.
*
* <p>If a file manager is provided, it must be able to handle all
* locations defined in {@link StandardLocation}.
*
* <p>Note that annotation processing can process both the
* compilation units of source code to be compiled, passed with
* the {@code compilationUnits} parameter, as well as class
* files, whose names are passed with the {@code classes}
* parameter.
*
* @param out a Writer for additional output from the compiler;
* use {@code System.err} if {@code null}
* @param fileManager a file manager; if {@code null} use the
* compiler's standard filemanager
* @param diagnosticListener a diagnostic listener; if {@code
* null} use the compiler's default method for reporting
* diagnostics
* @param options compiler options, {@code null} means no options
* @param classes names of classes to be processed by annotation
* processing, {@code null} means no class names
* @param compilationUnits the compilation units to compile, {@code
* null} means no compilation units
* @return an object representing the compilation
* @throws RuntimeException if an unrecoverable error
* occurred in a user supplied component. The
* {@linkplain Throwable#getCause() cause} will be the error in
* user code.
* @throws IllegalArgumentException if any of the options are invalid,
* or if any of the given compilation units are of other kind than
* {@linkplain JavaFileObject.Kind#SOURCE source}
*/
CompilationTask getTask(Writer out,
JavaFileManager fileManager,
DiagnosticListener<? super JavaFileObject> diagnosticListener,
Iterable<String> options,
Iterable<String> classes,
Iterable<? extends JavaFileObject> compilationUnits);
/**
* Returns a new instance of the standard file manager implementation
* for this tool. The file manager will use the given diagnostic
* listener for producing any non-fatal diagnostics. Fatal errors
* will be signaled with the appropriate exceptions.
*
* <p>The standard file manager will be automatically reopened if
* it is accessed after calls to {@code flush} or {@code close}.
* The standard file manager must be usable with other tools.
*
* @param diagnosticListener a diagnostic listener for non-fatal
* diagnostics; if {@code null} use the compiler's default method
* for reporting diagnostics
* @param locale the locale to apply when formatting diagnostics;
* {@code null} means the {@linkplain Locale#getDefault() default locale}.
* @param charset the character set used for decoding bytes; if
* {@code null} use the platform default
* @return the standard file manager
*/
StandardJavaFileManager getStandardFileManager(
DiagnosticListener<? super JavaFileObject> diagnosticListener,
Locale locale,
Charset charset);
/**
* Interface representing a future for a compilation task. The
* compilation task has not yet started. To start the task, call
* the {@linkplain #call call} method.
*
* <p>Before calling the call method, additional aspects of the
* task can be configured, for example, by calling the
* {@linkplain #setProcessors setProcessors} method.
*/
interface CompilationTask extends Callable<Boolean> {
/**
* Sets processors (for annotation processing). This will
* bypass the normal discovery mechanism.
*
* @param processors processors (for annotation processing)
* @throws IllegalStateException if the task has started
*/
void setProcessors(Iterable<? extends Processor> processors);
/**
* Set the locale to be applied when formatting diagnostics and
* other localized data.
*
* @param locale the locale to apply; {@code null} means apply no
* locale
* @throws IllegalStateException if the task has started
*/
void setLocale(Locale locale);
/**
* Performs this compilation task. The compilation may only
* be performed once. Subsequent calls to this method throw
* IllegalStateException.
*
* @return true if and only all the files compiled without errors;
* false otherwise
*
* @throws RuntimeException if an unrecoverable error occurred
* in a user-supplied component. The
* {@linkplain Throwable#getCause() cause} will be the error
* in user code.
* @throws IllegalStateException if called more than once
*/
Boolean call();
}
}