package org.checkerframework.javacutil;
import com.sun.source.tree.ClassTree;
import com.sun.source.util.JavacTask;
import com.sun.source.util.TaskEvent;
import com.sun.source.util.TaskListener;
import com.sun.source.util.TreePath;
import com.sun.source.util.Trees;
import com.sun.tools.javac.comp.CompileStates.CompileState;
import com.sun.tools.javac.main.JavaCompiler;
import com.sun.tools.javac.processing.JavacProcessingEnvironment;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.Log;
import java.util.HashSet;
import java.util.Set;
import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.ProcessingEnvironment;
import javax.annotation.processing.Processor;
import javax.annotation.processing.RoundEnvironment;
import javax.lang.model.element.Name;
import javax.lang.model.element.TypeElement;
import javax.lang.model.util.ElementFilter;
/**
* This class is an abstract annotation processor designed to be a convenient superclass for
* concrete "type processors", processors that require the type information in the processed source.
*
* <p>Type processing occurs in one round after the tool (e.g. Java compiler) analyzes the source
* (all sources taken as input to the tool and sources generated by other annotation processors).
*
* <p>The tool infrastructure will interact with classes extending this abstract class as follows.
*
* <p>1-3 are identical to the {@link Processor} life cycle. 4-5 are unique to {@code
* AbstractTypeProcessor} subclasses.
*
* <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>For each class containing a supported annotation, the tool calls {@link
* #typeProcess(TypeElement, TreePath) typeProcess} method on the {@code Processor}. The class
* is guaranteed to be type-checked Java code and all the tree type and symbol information is
* resolved.
* <li>Finally, the tools calls the {@link #typeProcessingOver() typeProcessingOver} method on the
* {@code Processor}.
* </ol>
*
* <p>The tool is permitted to ask type processors to process a class once it is analyzed before the
* rest of classes are analyzed. The tool is also permitted to stop type processing immediately if
* any errors are raised, without invoking {@code typeProcessingOver}
*
* <p>A subclass may override any of the methods in this class, as long as the general {@link
* javax.annotation.processing.Processor Processor} contract is obeyed, with one notable exception.
* {@link #process(Set, RoundEnvironment)} may not be overridden, as it is called during the
* declaration annotation phase before classes are analyzed.
*
* @author Mahmood Ali
* @author Werner Dietl
*/
public abstract class AbstractTypeProcessor extends AbstractProcessor {
/**
* The set of fully-qualified element names that should be type-checked. We store the names of
* the elements, in order to prevent possible confusion between different Element
* instantiations.
*/
private final Set<Name> elements = new HashSet<Name>();
/**
* Method {@link #typeProcessingStart()} must be invoked exactly once, before any invocation of
* {@link #typeProcess(TypeElement, TreePath)}.
*/
private boolean hasInvokedTypeProcessingStart = false;
/**
* Method {@link #typeProcessingOver()} must be invoked exactly once, after the last invocation
* of {@link #typeProcess(TypeElement, TreePath)}.
*/
private static boolean hasInvokedTypeProcessingOver = false;
/** The TaskListener registered for completion of attribution. */
private final AttributionTaskListener listener = new AttributionTaskListener();
/** Constructor for subclasses to call. */
protected AbstractTypeProcessor() {}
/**
* {@inheritDoc}
*
* <p>Register a TaskListener that will get called after FLOW.
*/
@Override
public synchronized void init(ProcessingEnvironment env) {
super.init(env);
JavacTask.instance(env).addTaskListener(listener);
Context ctx = ((JavacProcessingEnvironment) processingEnv).getContext();
JavaCompiler compiler = JavaCompiler.instance(ctx);
compiler.shouldStopPolicyIfNoError =
CompileState.max(compiler.shouldStopPolicyIfNoError, CompileState.FLOW);
compiler.shouldStopPolicyIfError =
CompileState.max(compiler.shouldStopPolicyIfError, CompileState.FLOW);
}
/**
* The use of this method is obsolete in type processors. The method is called during
* declaration annotation processing phase only. It registers the names of elements to process.
*/
@Override
public final boolean process(
Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
for (TypeElement elem : ElementFilter.typesIn(roundEnv.getRootElements())) {
elements.add(elem.getQualifiedName());
}
return false;
}
/**
* A method to be called once before the first call to typeProcess.
*
* <p>Subclasses may override this method to do any initialization work.
*/
public void typeProcessingStart() {}
/**
* Processes a fully-analyzed class that contains a supported annotation (see {@link
* #getSupportedAnnotationTypes()}).
*
* <p>The passed class is always valid type-checked Java code.
*
* @param element element of the analyzed class
* @param tree the tree path to the element, with the leaf being a {@link ClassTree}
*/
public abstract void typeProcess(TypeElement element, TreePath tree);
/**
* A method to be called once all the classes are processed and no error is reported.
*
* <p>Subclasses may override this method to do any aggregate analysis (e.g. generate report,
* persistence) or resource deallocation.
*
* <p>If an error (a Java error or a processor error) is reported, this method is not guaranteed
* to be invoked.
*/
public void typeProcessingOver() {}
/** A task listener that invokes the processor whenever a class is fully analyzed. */
private final class AttributionTaskListener implements TaskListener {
@Override
public void finished(TaskEvent e) {
if (e.getKind() != TaskEvent.Kind.ANALYZE) {
return;
}
if (!hasInvokedTypeProcessingStart) {
typeProcessingStart();
hasInvokedTypeProcessingStart = true;
}
Log log = Log.instance(((JavacProcessingEnvironment) processingEnv).getContext());
if (!hasInvokedTypeProcessingOver && elements.isEmpty() && log.nerrors == 0) {
typeProcessingOver();
hasInvokedTypeProcessingOver = true;
}
if (e.getTypeElement() == null) {
throw new AssertionError("event task without a type element");
}
if (e.getCompilationUnit() == null) {
throw new AssertionError("event task without compilation unit");
}
if (!elements.remove(e.getTypeElement().getQualifiedName())) {
return;
}
TypeElement elem = e.getTypeElement();
TreePath p = Trees.instance(processingEnv).getPath(elem);
typeProcess(elem, p);
if (!hasInvokedTypeProcessingOver && elements.isEmpty() && log.nerrors == 0) {
typeProcessingOver();
hasInvokedTypeProcessingOver = true;
}
}
@Override
public void started(TaskEvent e) {}
}
}