summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorGeorge Fraser <george@fivetran.com>2019-01-24 22:53:36 -0800
committerGeorge Fraser <george@fivetran.com>2019-03-31 10:49:44 -0700
commit31e0469b9ce63d39f8a732b32ae1afbc2e8e9d37 (patch)
tree4fb6a323f47710b33b1b50ca1f749d50e15e6995
parentf00234f1bc0949e21527c189ce7ceb33438ec932 (diff)
downloadjava-language-server-31e0469b9ce63d39f8a732b32ae1afbc2e8e9d37.zip
Demo how to re-use compiler
-rw-r--r--pom.xml18
-rw-r--r--src/main/java/org/javacs/SourceFileManager.java2
-rw-r--r--src/test/incremental-compile/src/foo/bar/Bar.java7
-rw-r--r--src/test/incremental-compile/src/foo/bar/Foo.java7
-rw-r--r--src/test/java/org/javacs/IncrementalCompileTest.java111
-rw-r--r--src/test/java/org/javacs/SimpleTest.java90
-rw-r--r--src/test/java/org/javacs/TaskPool.java379
7 files changed, 524 insertions, 90 deletions
diff --git a/pom.xml b/pom.xml
index b6aa940..509d8ee 100644
--- a/pom.xml
+++ b/pom.xml
@@ -7,6 +7,7 @@
<artifactId>javac-services</artifactId>
<packaging>jar</packaging>
<version>0.1-SNAPSHOT</version>
+
<distributionManagement>
<repository>
<id>distribution-repository</id>
@@ -14,6 +15,7 @@
<url>file://${basedir}/dist</url>
</repository>
</distributionManagement>
+
<dependencies>
<!-- JSON support -->
<dependency>
@@ -58,6 +60,22 @@
<configuration>
<source>11</source>
<target>11</target>
+ <compilerArgs>
+ <arg>--add-exports</arg>
+ <arg>jdk.compiler/com.sun.tools.javac.api=javacs</arg>
+ <arg>--add-exports</arg>
+ <arg>jdk.compiler/com.sun.tools.javac.code=javacs</arg>
+ <arg>--add-exports</arg>
+ <arg>jdk.compiler/com.sun.tools.javac.comp=javacs</arg>
+ <arg>--add-exports</arg>
+ <arg>jdk.compiler/com.sun.tools.javac.main=javacs</arg>
+ <arg>--add-exports</arg>
+ <arg>jdk.compiler/com.sun.tools.javac.tree=javacs</arg>
+ <arg>--add-exports</arg>
+ <arg>jdk.compiler/com.sun.tools.javac.model=javacs</arg>
+ <arg>--add-exports</arg>
+ <arg>jdk.compiler/com.sun.tools.javac.util=javacs</arg>
+ </compilerArgs>
<!-- Workaround of https://issues.apache.org/jira/browse/MCOMPILER-369 -->
<annotationProcessorPaths>
<path>
diff --git a/src/main/java/org/javacs/SourceFileManager.java b/src/main/java/org/javacs/SourceFileManager.java
index dfef972..d630988 100644
--- a/src/main/java/org/javacs/SourceFileManager.java
+++ b/src/main/java/org/javacs/SourceFileManager.java
@@ -22,6 +22,8 @@ class SourceFileManager extends ForwardingJavaFileManager<StandardJavaFileManage
LOG.warning(error.getMessage(null));
}
+ // TODO if .class files get moved around, this could become wrong
+ // class path includes generated .class files, so this can definitely happen
private final LruCache<String, Iterable<JavaFileObject>> cacheClassPath = new LruCache<>(1000, this::listClassPath);
@Override
diff --git a/src/test/incremental-compile/src/foo/bar/Bar.java b/src/test/incremental-compile/src/foo/bar/Bar.java
new file mode 100644
index 0000000..0f0829a
--- /dev/null
+++ b/src/test/incremental-compile/src/foo/bar/Bar.java
@@ -0,0 +1,7 @@
+package foo.bar;
+
+class Bar {
+ static int test() {
+ return 1;
+ }
+} \ No newline at end of file
diff --git a/src/test/incremental-compile/src/foo/bar/Foo.java b/src/test/incremental-compile/src/foo/bar/Foo.java
new file mode 100644
index 0000000..dea73d5
--- /dev/null
+++ b/src/test/incremental-compile/src/foo/bar/Foo.java
@@ -0,0 +1,7 @@
+package foo.bar;
+
+class Foo {
+ static void test() {
+ var x = Bar.test();
+ }
+} \ No newline at end of file
diff --git a/src/test/java/org/javacs/IncrementalCompileTest.java b/src/test/java/org/javacs/IncrementalCompileTest.java
new file mode 100644
index 0000000..6cd03fb
--- /dev/null
+++ b/src/test/java/org/javacs/IncrementalCompileTest.java
@@ -0,0 +1,111 @@
+package org.javacs;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+import com.sun.source.tree.MethodInvocationTree;
+import com.sun.source.util.*;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.List;
+import java.util.ServiceLoader;
+import java.util.logging.Logger;
+import javax.tools.Diagnostic;
+import javax.tools.DiagnosticListener;
+import javax.tools.JavaCompiler;
+import javax.tools.JavaFileObject;
+import org.junit.Before;
+import org.junit.Test;
+
+public class IncrementalCompileTest implements TaskListener, DiagnosticListener<JavaFileObject> {
+ final JavaCompiler compiler = ServiceLoader.load(JavaCompiler.class).iterator().next();
+ final Path src = Paths.get("src/test/incremental-compile/src").toAbsolutePath();
+ final Path foo = src.resolve("foo/bar/Foo.java");
+ final List<String> options = List.of("-sourcepath", src.toString(), "-verbose", "-proc:none");
+
+ @Before
+ public void setLogFormat() {
+ Main.setRootFormat();
+ }
+
+ @Test
+ public void freshTask() {
+ var fileManager = compiler.getStandardFileManager(this, null, Charset.defaultCharset());
+ for (var i = 0; i < 2; i++) {
+ LOG.info(String.format("Compile %d...", i));
+ var files = fileManager.getJavaFileObjects(foo);
+ var task = (JavacTask) compiler.getTask(null, fileManager, this, options, null, files);
+ checkInvokeType(task);
+ }
+ }
+
+ @Test
+ public void taskPool() {
+ var fileManager = compiler.getStandardFileManager(this, null, Charset.defaultCharset());
+ var pool = new TaskPool(1);
+ for (var i = 0; i < 2; i++) {
+ var files = fileManager.getJavaFileObjects(foo);
+ LOG.info(String.format("Compile %d...", i));
+ pool.getTask(
+ null,
+ fileManager,
+ this,
+ options,
+ null,
+ files,
+ task -> {
+ checkInvokeType(task);
+ return "Done!";
+ });
+ }
+ }
+
+ private void checkInvokeType(JavacTask task) {
+ task.addTaskListener(this);
+ try {
+ var root = task.parse().iterator().next();
+ task.analyze();
+ LOG.info("Scan " + root);
+ new TreePathScanner<Void, Void>() {
+ @Override
+ public Void visitMethodInvocation(MethodInvocationTree t, Void __) {
+ if (t.getMethodSelect().toString().equals("Bar.test")) {
+ var type = Trees.instance(task).getTypeMirror(getCurrentPath());
+ LOG.info("Check " + t + ": " + type);
+ assertThat(type.toString(), equalTo("int"));
+ }
+ return null;
+ }
+ }.scan(root, null);
+ } catch (IOException e) {
+ throw new RuntimeException(e);
+ }
+ }
+
+ @Override
+ public void report(Diagnostic<? extends JavaFileObject> d) {
+ LOG.warning(d.getMessage(null));
+ }
+
+ @Override
+ public void started(TaskEvent e) {
+ if (e.getSourceFile() == null) {
+ LOG.info(String.format("...started %s", e.getKind()));
+ return;
+ }
+ LOG.info(String.format("...started %s %s", e.getKind(), e.getSourceFile().getName()));
+ }
+
+ @Override
+ public void finished(TaskEvent e) {
+ if (e.getSourceFile() == null) {
+ LOG.info(String.format("...finished %s", e.getKind()));
+ return;
+ }
+ LOG.info(String.format("...finished %s %s", e.getKind(), e.getSourceFile().getName()));
+ }
+
+ private static final Logger LOG = Logger.getLogger("main");
+}
diff --git a/src/test/java/org/javacs/SimpleTest.java b/src/test/java/org/javacs/SimpleTest.java
deleted file mode 100644
index 7f46eb7..0000000
--- a/src/test/java/org/javacs/SimpleTest.java
+++ /dev/null
@@ -1,90 +0,0 @@
-package org.javacs;
-
-import com.sun.source.util.JavacTask;
-import com.sun.source.util.TaskEvent;
-import com.sun.source.util.TaskListener;
-import java.io.IOException;
-import java.nio.charset.Charset;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.util.*;
-import java.util.logging.Logger;
-import javax.tools.*;
-import org.junit.Before;
-import org.junit.Test;
-
-public class SimpleTest implements TaskListener, DiagnosticListener<JavaFileObject> {
- final JavaCompiler compiler = ServiceLoader.load(JavaCompiler.class).iterator().next();
- final Path src = Paths.get("src/main/java").toAbsolutePath();
- final List<String> options = List.of("-sourcepath", src.toString(), "-verbose", "-proc:none");
-
- @Before
- public void setLogFormat() {
- Main.setRootFormat();
- }
-
- @Test
- public void standardFileManager() throws IOException {
- var fileManager = compiler.getStandardFileManager(this, null, Charset.defaultCharset());
-
- LOG.info("Compile once...");
- var files = fileManager.getJavaFileObjects(src.resolve("org/javacs/JavaLanguageServer.java"));
- var task = (JavacTask) compiler.getTask(null, fileManager, this, options, null, files);
-
- task.addTaskListener(this);
- task.analyze();
-
- LOG.info("Compile twice...");
- task = (JavacTask) compiler.getTask(null, fileManager, this, options, null, files);
- task.addTaskListener(this);
- task.analyze();
- }
-
- @Test
- public void sourceFileManager() throws IOException {
- FileStore.setWorkspaceRoots(Set.of(Paths.get(".").toAbsolutePath()));
- var fileManager = new SourceFileManager();
-
- LOG.info("Compile once...");
- var files =
- fileManager.getJavaFileObjectsFromFiles(
- List.of(src.resolve("org/javacs/JavaLanguageServer.java").toFile()));
- var task = (JavacTask) compiler.getTask(null, fileManager, this, options, null, files);
- task.addTaskListener(this);
- task.analyze();
- LOG.info("...finished once");
-
- for (var i = 0; i < 3; i++) {
- LOG.info(String.format("Compile again %d...", i));
- task = (JavacTask) compiler.getTask(null, fileManager, this, options, null, files);
- task.addTaskListener(this);
- task.analyze();
- LOG.info(String.format("...finished %d", i));
- }
- }
-
- @Override
- public void report(Diagnostic<? extends JavaFileObject> d) {
- LOG.warning(d.getMessage(null));
- }
-
- @Override
- public void started(TaskEvent e) {
- if (e.getSourceFile() == null) {
- LOG.info(String.format("...started %s", e.getKind()));
- return;
- }
- LOG.info(String.format("...started %s %s", e.getKind(), e.getSourceFile().getName()));
- }
-
- @Override
- public void finished(TaskEvent e) {
- if (e.getSourceFile() == null) {
- LOG.info(String.format("...finished %s", e.getKind()));
- return;
- }
- LOG.info(String.format("...finished %s %s", e.getKind(), e.getSourceFile().getName()));
- }
-
- private static final Logger LOG = Logger.getLogger("main");
-}
diff --git a/src/test/java/org/javacs/TaskPool.java b/src/test/java/org/javacs/TaskPool.java
new file mode 100644
index 0000000..ecd40d3
--- /dev/null
+++ b/src/test/java/org/javacs/TaskPool.java
@@ -0,0 +1,379 @@
+// Forked from JavacTaskImpl
+/*
+ * Copyright (c) 2015, 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 org.javacs;
+
+import com.sun.source.tree.CompilationUnitTree;
+import com.sun.source.util.JavacTask;
+import com.sun.source.util.TaskEvent;
+import com.sun.source.util.TaskEvent.Kind;
+import com.sun.source.util.TaskListener;
+import com.sun.tools.javac.api.*;
+import com.sun.tools.javac.code.Symtab;
+import com.sun.tools.javac.code.Types;
+import com.sun.tools.javac.comp.Annotate;
+import com.sun.tools.javac.comp.Check;
+import com.sun.tools.javac.comp.CompileStates;
+import com.sun.tools.javac.comp.Enter;
+import com.sun.tools.javac.comp.Modules;
+import com.sun.tools.javac.main.Arguments;
+import com.sun.tools.javac.main.JavaCompiler;
+import com.sun.tools.javac.model.JavacElements;
+import com.sun.tools.javac.util.Context;
+import com.sun.tools.javac.util.DefinedBy;
+import com.sun.tools.javac.util.DefinedBy.Api;
+import com.sun.tools.javac.util.Log;
+import java.io.PrintStream;
+import java.io.Writer;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
+import javax.tools.Diagnostic;
+import javax.tools.DiagnosticListener;
+import javax.tools.JavaFileManager;
+import javax.tools.JavaFileObject;
+
+/**
+ * A pool of reusable JavacTasks. When a task is no valid anymore, it is returned to the pool, and its Context may be
+ * reused for future processing in some cases. The reuse is achieved by replacing some components (most notably
+ * JavaCompiler and Log) with reusable counterparts, and by cleaning up leftovers from previous compilation.
+ *
+ * <p>For each combination of options, a separate task/context is created and kept, as most option values are cached
+ * inside components themselves.
+ *
+ * <p>When the compilation redefines sensitive classes (e.g. classes in the the java.* packages), the task/context is
+ * not reused.
+ *
+ * <p>When the task is reused, then packages that were already listed won't be listed again.
+ *
+ * <p>Care must be taken to only return tasks that won't be used by the original caller.
+ *
+ * <p>Care must also be taken when custom components are installed, as those are not cleaned when the task/context is
+ * reused, and subsequent getTask may return a task based on a context with these custom components.
+ *
+ * <p><b>This is NOT part of any supported API. If you write code that depends on this, you do so at your own risk. This
+ * code and its internal interfaces are subject to change or deletion without notice.</b>
+ */
+public class TaskPool {
+
+ private static final JavacTool systemProvider = JavacTool.create();
+
+ private final int maxPoolSize;
+ private final Map<List<String>, List<ReusableContext>> options2Contexts = new HashMap<>();
+ private int id;
+
+ private int statReused = 0;
+ private int statNew = 0;
+ private int statPolluted = 0;
+ private int statRemoved = 0;
+
+ /**
+ * Creates the pool.
+ *
+ * @param maxPoolSize maximum number of tasks/context that will be kept in the pool.
+ */
+ public TaskPool(int maxPoolSize) {
+ this.maxPoolSize = maxPoolSize;
+ }
+
+ /**
+ * Creates a new task as if by {@link javax.tools.JavaCompiler#getTask} and runs the provided worker with it. The
+ * task is only valid while the worker is running. The internal structures may be reused from some previous
+ * compilation.
+ *
+ * @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
+ * @param worker that should be run with the task
+ * @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}
+ */
+ public <Z> Z getTask(
+ Writer out,
+ JavaFileManager fileManager,
+ DiagnosticListener<? super JavaFileObject> diagnosticListener,
+ Iterable<String> options,
+ Iterable<String> classes,
+ Iterable<? extends JavaFileObject> compilationUnits,
+ Worker<Z> worker) {
+ List<String> opts =
+ StreamSupport.stream(options.spliterator(), false).collect(Collectors.toCollection(ArrayList::new));
+
+ ReusableContext ctx;
+
+ synchronized (this) {
+ List<ReusableContext> cached = options2Contexts.getOrDefault(opts, Collections.emptyList());
+
+ if (cached.isEmpty()) {
+ ctx = new ReusableContext(opts);
+ statNew++;
+ } else {
+ ctx = cached.remove(0);
+ statReused++;
+ }
+ }
+
+ ctx.useCount++;
+
+ JavacTaskImpl task =
+ (JavacTaskImpl)
+ systemProvider.getTask(
+ out, fileManager, diagnosticListener, opts, classes, compilationUnits, ctx);
+
+ task.addTaskListener(ctx);
+
+ Z result = worker.withTask(task);
+
+ // not returning the context to the pool if task crashes with an exception
+ // the task/context may be in a broken state
+ ctx.clear();
+ if (ctx.polluted) {
+ statPolluted++;
+ } else {
+ // task.cleanup();
+ synchronized (this) {
+ while (cacheSize() + 1 > maxPoolSize) {
+ ReusableContext toRemove =
+ options2Contexts
+ .values()
+ .stream()
+ .flatMap(Collection::stream)
+ .sorted((c1, c2) -> c1.timeStamp < c2.timeStamp ? -1 : 1)
+ .findFirst()
+ .get();
+ options2Contexts.get(toRemove.arguments).remove(toRemove);
+ statRemoved++;
+ }
+ options2Contexts.computeIfAbsent(ctx.arguments, x -> new ArrayList<>()).add(ctx);
+ ctx.timeStamp = id++;
+ }
+ }
+
+ return result;
+ }
+ // where:
+ private long cacheSize() {
+ return options2Contexts.values().stream().flatMap(Collection::stream).count();
+ }
+
+ public void printStatistics(PrintStream out) {
+ out.println(statReused + " reused Contexts");
+ out.println(statNew + " newly created Contexts");
+ out.println(statPolluted + " polluted Contexts");
+ out.println(statRemoved + " removed Contexts");
+ }
+
+ public interface Worker<Z> {
+ public Z withTask(JavacTask task);
+ }
+
+ static class ReusableContext extends Context implements TaskListener {
+
+ Set<CompilationUnitTree> roots = new HashSet<>();
+
+ List<String> arguments;
+ boolean polluted = false;
+
+ int useCount;
+ long timeStamp;
+
+ ReusableContext(List<String> arguments) {
+ super();
+ this.arguments = arguments;
+ put(Log.logKey, ReusableLog.factory);
+ put(JavaCompiler.compilerKey, ReusableJavaCompiler.factory);
+ }
+
+ void clear() {
+ drop(Arguments.argsKey);
+ drop(DiagnosticListener.class);
+ drop(Log.outKey);
+ drop(Log.errKey);
+ drop(JavaFileManager.class);
+ drop(JavacTask.class);
+ drop(JavacTrees.class);
+ drop(JavacElements.class);
+
+ if (ht.get(Log.logKey) instanceof ReusableLog) {
+ // log already inited - not first round
+ ((ReusableLog) Log.instance(this)).clear();
+ Enter.instance(this).newRound();
+ ((ReusableJavaCompiler) ReusableJavaCompiler.instance(this)).clear();
+ Types.instance(this).newRound();
+ Check.instance(this).newRound();
+ Modules.instance(this).newRound();
+ Annotate.instance(this).newRound();
+ CompileStates.instance(this).clear();
+ MultiTaskListener.instance(this).clear();
+
+ // find if any of the roots have redefined java.* classes
+ Symtab syms = Symtab.instance(this);
+ // pollutionScanner.scan(roots, syms);
+ roots.clear();
+ }
+ }
+
+ /**
+ * This scanner detects as to whether the shared context has been polluted. This happens whenever a compiled
+ * program redefines a core class (in 'java.*' package) or when (typically because of cyclic inheritance) the
+ * symbol kind of a core class has been touched.
+ */
+ /*
+ TreeScanner<Void, Symtab> pollutionScanner = new TreeScanner<Void, Symtab>() {
+ @Override @DefinedBy(Api.COMPILER_TREE)
+ public Void visitClass(ClassTree node, Symtab syms) {
+ Symbol sym = ((JCClassDecl)node).sym;
+ if (sym != null) {
+ syms.removeClass(sym.packge().modle, sym.flatName());
+ Type sup = supertype(sym);
+ if (isCoreClass(sym) ||
+ (sup != null && isCoreClass(sup.tsym) && sup.tsym.kind != Kinds.Kind.TYP)) {
+ polluted = true;
+ }
+ }
+ return super.visitClass(node, syms);
+ }
+
+ private boolean isCoreClass(Symbol s) {
+ return s.flatName().toString().startsWith("java.");
+ }
+
+ private Type supertype(Symbol s) {
+ if (s.type == null ||
+ !s.type.hasTag(TypeTag.CLASS)) {
+ return null;
+ } else {
+ ClassType ct = (ClassType)s.type;
+ return ct.supertype_field;
+ }
+ }
+ };
+ */
+
+ @Override
+ @DefinedBy(Api.COMPILER_TREE)
+ public void finished(TaskEvent e) {
+ if (e.getKind() == Kind.PARSE) {
+ roots.add(e.getCompilationUnit());
+ }
+ }
+
+ @Override
+ @DefinedBy(Api.COMPILER_TREE)
+ public void started(TaskEvent e) {
+ // do nothing
+ }
+
+ <T> void drop(Key<T> k) {
+ ht.remove(k);
+ }
+
+ <T> void drop(Class<T> c) {
+ ht.remove(key(c));
+ }
+
+ /**
+ * Reusable JavaCompiler; exposes a method to clean up the component from leftovers associated with previous
+ * compilations.
+ */
+ static class ReusableJavaCompiler extends JavaCompiler {
+
+ static final Factory<JavaCompiler> factory = ReusableJavaCompiler::new;
+
+ ReusableJavaCompiler(Context context) {
+ super(context);
+ }
+
+ @Override
+ public void close() {
+ // do nothing
+ }
+
+ void clear() {
+ newRound();
+ }
+
+ @Override
+ protected void checkReusable() {
+ // do nothing - it's ok to reuse the compiler
+ }
+ }
+
+ /**
+ * Reusable Log; exposes a method to clean up the component from leftovers associated with previous
+ * compilations.
+ */
+ static class ReusableLog extends Log {
+
+ static final Factory<Log> factory = ReusableLog::new;
+
+ Context context;
+
+ ReusableLog(Context context) {
+ super(context);
+ this.context = context;
+ }
+
+ void clear() {
+ recorded.clear();
+ sourceMap.clear();
+ nerrors = 0;
+ nwarnings = 0;
+ // Set a fake listener that will lazily lookup the context for the 'real' listener. Since
+ // this field is never updated when a new task is created, we cannot simply reset the field
+ // or keep old value. This is a hack to workaround the limitations in the current infrastructure.
+ diagListener =
+ new DiagnosticListener<JavaFileObject>() {
+ DiagnosticListener<JavaFileObject> cachedListener;
+
+ @Override
+ @DefinedBy(Api.COMPILER)
+ @SuppressWarnings("unchecked")
+ public void report(Diagnostic<? extends JavaFileObject> diagnostic) {
+ if (cachedListener == null) {
+ cachedListener = context.get(DiagnosticListener.class);
+ }
+ cachedListener.report(diagnostic);
+ }
+ };
+ }
+ }
+ }
+}