--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Analyzer.java Fri Dec 12 18:07:24 2014 +0000
@@ -0,0 +1,493 @@
+/*
+ * Copyright (c) 2014, 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 com.sun.tools.javac.comp;
+
+import com.sun.tools.javac.code.Source;
+import com.sun.tools.javac.code.Type;
+import com.sun.tools.javac.code.Types;
+import com.sun.tools.javac.tree.JCTree;
+import com.sun.tools.javac.tree.JCTree.JCBlock;
+import com.sun.tools.javac.tree.JCTree.JCClassDecl;
+import com.sun.tools.javac.tree.JCTree.JCDoWhileLoop;
+import com.sun.tools.javac.tree.JCTree.JCEnhancedForLoop;
+import com.sun.tools.javac.tree.JCTree.JCForLoop;
+import com.sun.tools.javac.tree.JCTree.JCIf;
+import com.sun.tools.javac.tree.JCTree.JCLambda;
+import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
+import com.sun.tools.javac.tree.JCTree.JCMethodInvocation;
+import com.sun.tools.javac.tree.JCTree.JCNewClass;
+import com.sun.tools.javac.tree.JCTree.JCStatement;
+import com.sun.tools.javac.tree.JCTree.JCSwitch;
+import com.sun.tools.javac.tree.JCTree.JCTypeApply;
+import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
+import com.sun.tools.javac.tree.JCTree.JCWhileLoop;
+import com.sun.tools.javac.tree.JCTree.Tag;
+import com.sun.tools.javac.tree.TreeCopier;
+import com.sun.tools.javac.tree.TreeInfo;
+import com.sun.tools.javac.tree.TreeMaker;
+import com.sun.tools.javac.tree.TreeScanner;
+import com.sun.tools.javac.util.Context;
+import com.sun.tools.javac.util.Filter;
+import com.sun.tools.javac.util.JCDiagnostic;
+import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
+import com.sun.tools.javac.util.List;
+import com.sun.tools.javac.util.ListBuffer;
+import com.sun.tools.javac.util.Log;
+import com.sun.tools.javac.util.Names;
+import com.sun.tools.javac.util.Options;
+
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Predicate;
+
+import static com.sun.tools.javac.code.Flags.GENERATEDCONSTR;
+import static com.sun.tools.javac.code.Flags.SYNTHETIC;
+import static com.sun.tools.javac.code.TypeTag.CLASS;
+import static com.sun.tools.javac.tree.JCTree.Tag.APPLY;
+import static com.sun.tools.javac.tree.JCTree.Tag.CLASSDEF;
+import static com.sun.tools.javac.tree.JCTree.Tag.METHODDEF;
+import static com.sun.tools.javac.tree.JCTree.Tag.NEWCLASS;
+import static com.sun.tools.javac.tree.JCTree.Tag.TYPEAPPLY;
+
+/**
+ * Helper class for defining custom code analysis, such as finding instance creation expression
+ * that can benefit from diamond syntax.
+ */
+public class Analyzer {
+ protected static final Context.Key<Analyzer> analyzerKey = new Context.Key<>();
+
+ final Types types;
+ final Log log;
+ final Attr attr;
+ final DeferredAttr deferredAttr;
+ final TreeMaker make;
+ final Names names;
+
+ final EnumSet<AnalyzerMode> analyzerModes;
+
+ public static Analyzer instance(Context context) {
+ Analyzer instance = context.get(analyzerKey);
+ if (instance == null)
+ instance = new Analyzer(context);
+ return instance;
+ }
+
+ protected Analyzer(Context context) {
+ context.put(analyzerKey, this);
+ types = Types.instance(context);
+ log = Log.instance(context);
+ attr = Attr.instance(context);
+ deferredAttr = DeferredAttr.instance(context);
+ make = TreeMaker.instance(context);
+ names = Names.instance(context);
+ Options options = Options.instance(context);
+ String findOpt = options.get("find");
+ //parse modes
+ Source source = Source.instance(context);
+ analyzerModes = AnalyzerMode.getAnalyzerModes(findOpt, source);
+ }
+
+ /**
+ * This enum defines supported analyzer modes, as well as defining the logic for decoding
+ * the {@code -XDfind} option.
+ */
+ enum AnalyzerMode {
+ DIAMOND("diamond", Source::allowDiamond),
+ LAMBDA("lambda", Source::allowLambda),
+ METHOD("method", Source::allowGraphInference);
+
+ final String opt;
+ final Predicate<Source> sourceFilter;
+
+ AnalyzerMode(String opt, Predicate<Source> sourceFilter) {
+ this.opt = opt;
+ this.sourceFilter = sourceFilter;
+ }
+
+ /**
+ * This method is used to parse the {@code find} option.
+ * Possible modes are separated by colon; a mode can be excluded by
+ * prepending '-' to its name. Finally, the special mode 'all' can be used to
+ * add all modes to the resulting enum.
+ */
+ static EnumSet<AnalyzerMode> getAnalyzerModes(String opt, Source source) {
+ if (opt == null) {
+ return EnumSet.noneOf(AnalyzerMode.class);
+ }
+ List<String> modes = List.from(opt.split(","));
+ EnumSet<AnalyzerMode> res = EnumSet.noneOf(AnalyzerMode.class);
+ if (modes.contains("all")) {
+ res = EnumSet.allOf(AnalyzerMode.class);
+ }
+ for (AnalyzerMode mode : values()) {
+ if (modes.contains(mode.opt)) {
+ res.add(mode);
+ } else if (modes.contains("-" + mode.opt) || !mode.sourceFilter.test(source)) {
+ res.remove(mode);
+ }
+ }
+ return res;
+ }
+ }
+
+ /**
+ * A statement analyzer is a work-unit that matches certain AST nodes (of given type {@code S}),
+ * rewrites them to different AST nodes (of type {@code T}) and then generates some meaningful
+ * messages in case the analysis has been successful.
+ */
+ abstract class StatementAnalyzer<S extends JCTree, T extends JCTree> {
+
+ AnalyzerMode mode;
+ JCTree.Tag tag;
+
+ StatementAnalyzer(AnalyzerMode mode, Tag tag) {
+ this.mode = mode;
+ this.tag = tag;
+ }
+
+ /**
+ * Is this analyzer allowed to run?
+ */
+ boolean isEnabled() {
+ return analyzerModes.contains(mode);
+ }
+
+ /**
+ * Should this analyzer be rewriting the given tree?
+ */
+ abstract boolean match(S tree);
+
+ /**
+ * Rewrite a given AST node into a new one
+ */
+ abstract T map(S oldTree, S newTree);
+
+ /**
+ * Entry-point for comparing results and generating diagnostics.
+ */
+ abstract void process(S oldTree, T newTree, boolean hasErrors);
+
+ }
+
+ /**
+ * This analyzer checks if generic instance creation expression can use diamond syntax.
+ */
+ class DiamondInitializer extends StatementAnalyzer<JCNewClass, JCNewClass> {
+
+ DiamondInitializer() {
+ super(AnalyzerMode.DIAMOND, NEWCLASS);
+ }
+
+ @Override
+ boolean match(JCNewClass tree) {
+ return tree.clazz.hasTag(TYPEAPPLY) &&
+ !TreeInfo.isDiamond(tree) &&
+ tree.def == null;
+ }
+
+ @Override
+ JCNewClass map(JCNewClass oldTree, JCNewClass newTree) {
+ if (newTree.clazz.hasTag(TYPEAPPLY)) {
+ ((JCTypeApply)newTree.clazz).arguments = List.nil();
+ }
+ return newTree;
+ }
+
+ @Override
+ void process(JCNewClass oldTree, JCNewClass newTree, boolean hasErrors) {
+ if (!hasErrors) {
+ List<Type> inferredArgs = newTree.type.getTypeArguments();
+ List<Type> explicitArgs = oldTree.type.getTypeArguments();
+ for (Type t : inferredArgs) {
+ if (!types.isSameType(t, explicitArgs.head)) {
+ log.warning(oldTree.clazz, "diamond.redundant.args.1",
+ oldTree.clazz.type, newTree.clazz.type);
+ return;
+ }
+ explicitArgs = explicitArgs.tail;
+ }
+ //exact match
+ log.warning(oldTree.clazz, "diamond.redundant.args");
+ }
+ }
+ }
+
+ /**
+ * This analyzer checks if anonymous instance creation expression can replaced by lambda.
+ */
+ class LambdaAnalyzer extends StatementAnalyzer<JCNewClass, JCLambda> {
+
+ LambdaAnalyzer() {
+ super(AnalyzerMode.LAMBDA, NEWCLASS);
+ }
+
+ @Override
+ boolean match (JCNewClass tree){
+ Type clazztype = tree.clazz.type;
+ return tree.def != null &&
+ clazztype.hasTag(CLASS) &&
+ types.isFunctionalInterface(clazztype.tsym) &&
+ decls(tree.def).length() == 1;
+ }
+ //where
+ private List<JCTree> decls(JCClassDecl decl) {
+ ListBuffer<JCTree> decls = new ListBuffer<>();
+ for (JCTree t : decl.defs) {
+ if (t.hasTag(METHODDEF)) {
+ JCMethodDecl md = (JCMethodDecl)t;
+ if ((md.getModifiers().flags & GENERATEDCONSTR) == 0) {
+ decls.add(md);
+ }
+ } else {
+ decls.add(t);
+ }
+ }
+ return decls.toList();
+ }
+
+ @Override
+ JCLambda map (JCNewClass oldTree, JCNewClass newTree){
+ JCMethodDecl md = (JCMethodDecl)decls(newTree.def).head;
+ List<JCVariableDecl> params = md.params;
+ JCBlock body = md.body;
+ return make.Lambda(params, body);
+ }
+ @Override
+ void process (JCNewClass oldTree, JCLambda newTree, boolean hasErrors){
+ if (!hasErrors) {
+ log.warning(oldTree.def, "potential.lambda.found");
+ }
+ }
+ }
+
+ /**
+ * This analyzer checks if generic method call has redundant type arguments.
+ */
+ class RedundantTypeArgAnalyzer extends StatementAnalyzer<JCMethodInvocation, JCMethodInvocation> {
+
+ RedundantTypeArgAnalyzer() {
+ super(AnalyzerMode.METHOD, APPLY);
+ }
+
+ @Override
+ boolean match (JCMethodInvocation tree){
+ return tree.typeargs != null &&
+ tree.typeargs.nonEmpty();
+ }
+ @Override
+ JCMethodInvocation map (JCMethodInvocation oldTree, JCMethodInvocation newTree){
+ newTree.typeargs = List.nil();
+ return newTree;
+ }
+ @Override
+ void process (JCMethodInvocation oldTree, JCMethodInvocation newTree, boolean hasErrors){
+ if (!hasErrors) {
+ //exact match
+ log.warning(oldTree, "method.redundant.typeargs");
+ }
+ }
+ }
+
+ @SuppressWarnings({"unchecked", "rawtypes"})
+ StatementAnalyzer<JCTree, JCTree>[] analyzers = new StatementAnalyzer[] {
+ new DiamondInitializer(),
+ new LambdaAnalyzer(),
+ new RedundantTypeArgAnalyzer()
+ };
+
+ /**
+ * Analyze an AST node if needed.
+ */
+ void analyzeIfNeeded(JCTree tree, Env<AttrContext> env) {
+ if (!analyzerModes.isEmpty() &&
+ !env.info.isSpeculative &&
+ TreeInfo.isStatement(tree)) {
+ JCStatement stmt = (JCStatement)tree;
+ analyze(stmt, env);
+ }
+ }
+
+ /**
+ * Analyze an AST node; this involves collecting a list of all the nodes that needs rewriting,
+ * and speculatively type-check the rewritten code to compare results against previously attributed code.
+ */
+ void analyze(JCStatement statement, Env<AttrContext> env) {
+ AnalysisContext context = new AnalysisContext();
+ StatementScanner statementScanner = new StatementScanner(context);
+ statementScanner.scan(statement);
+
+ if (!context.treesToAnalyzer.isEmpty()) {
+
+ //add a block to hoist potential dangling variable declarations
+ JCBlock fakeBlock = make.Block(SYNTHETIC, List.of(statement));
+
+ TreeMapper treeMapper = new TreeMapper(context);
+ //TODO: to further refine the analysis, try all rewriting combinations
+ deferredAttr.attribSpeculative(fakeBlock, env, attr.statInfo, treeMapper,
+ t -> new AnalyzeDeferredDiagHandler(context));
+
+ context.treeMap.entrySet().forEach(e -> {
+ context.treesToAnalyzer.get(e.getKey())
+ .process(e.getKey(), e.getValue(), context.errors.nonEmpty());
+ });
+ }
+ }
+
+ /**
+ * Simple deferred diagnostic handler which filters out all messages and keep track of errors.
+ */
+ class AnalyzeDeferredDiagHandler extends Log.DeferredDiagnosticHandler {
+ AnalysisContext context;
+
+ public AnalyzeDeferredDiagHandler(AnalysisContext context) {
+ super(log, d -> {
+ if (d.getType() == DiagnosticType.ERROR) {
+ context.errors.add(d);
+ }
+ return true;
+ });
+ this.context = context;
+ }
+ }
+
+ /**
+ * This class is used to pass around contextual information bewteen analyzer classes, such as
+ * trees to be rewritten, errors occurred during the speculative attribution step, etc.
+ */
+ class AnalysisContext {
+ /** Map from trees to analyzers. */
+ Map<JCTree, StatementAnalyzer<JCTree, JCTree>> treesToAnalyzer = new HashMap<>();
+
+ /** Map from original AST nodes to rewritten AST nodes */
+ Map<JCTree, JCTree> treeMap = new HashMap<>();
+
+ /** Errors in rewritten tree */
+ ListBuffer<JCDiagnostic> errors = new ListBuffer<>();
+ }
+
+ /**
+ * Subclass of {@link com.sun.tools.javac.tree.TreeScanner} which visit AST-nodes w/o crossing
+ * statement boundaries.
+ */
+ class StatementScanner extends TreeScanner {
+
+ /** context */
+ AnalysisContext context;
+
+ StatementScanner(AnalysisContext context) {
+ this.context = context;
+ }
+
+ @Override
+ @SuppressWarnings("unchecked")
+ public void scan(JCTree tree) {
+ if (tree != null) {
+ for (StatementAnalyzer<JCTree, JCTree> analyzer : analyzers) {
+ if (analyzer.isEnabled() &&
+ tree.hasTag(analyzer.tag) &&
+ analyzer.match(tree)) {
+ context.treesToAnalyzer.put(tree, analyzer);
+ break; //TODO: cover cases where multiple matching analyzers are found
+ }
+ }
+ }
+ super.scan(tree);
+ }
+
+ @Override
+ public void visitClassDef(JCClassDecl tree) {
+ //do nothing (prevents seeing same stuff twice
+ }
+
+ @Override
+ public void visitMethodDef(JCMethodDecl tree) {
+ //do nothing (prevents seeing same stuff twice
+ }
+
+ @Override
+ public void visitBlock(JCBlock tree) {
+ //do nothing (prevents seeing same stuff twice
+ }
+
+ @Override
+ public void visitSwitch(JCSwitch tree) {
+ scan(tree.getExpression());
+ }
+
+ @Override
+ public void visitForLoop(JCForLoop tree) {
+ scan(tree.getInitializer());
+ scan(tree.getCondition());
+ scan(tree.getUpdate());
+ }
+
+ @Override
+ public void visitForeachLoop(JCEnhancedForLoop tree) {
+ scan(tree.getExpression());
+ }
+
+ @Override
+ public void visitWhileLoop(JCWhileLoop tree) {
+ scan(tree.getCondition());
+ }
+
+ @Override
+ public void visitDoLoop(JCDoWhileLoop tree) {
+ scan(tree.getCondition());
+ }
+
+ @Override
+ public void visitIf(JCIf tree) {
+ scan(tree.getCondition());
+ }
+ }
+
+ /**
+ * Subclass of TreeCopier that maps nodes matched by analyzers onto new AST nodes.
+ */
+ class TreeMapper extends TreeCopier<Void> {
+
+ AnalysisContext context;
+
+ TreeMapper(AnalysisContext context) {
+ super(make);
+ this.context = context;
+ }
+
+ @Override
+ @SuppressWarnings("unchecked")
+ public <Z extends JCTree> Z copy(Z tree, Void _unused) {
+ Z newTree = super.copy(tree, _unused);
+ StatementAnalyzer<JCTree, JCTree> analyzer = context.treesToAnalyzer.get(tree);
+ if (analyzer != null) {
+ newTree = (Z)analyzer.map(tree, newTree);
+ context.treeMap.put(tree, newTree);
+ }
+ return newTree;
+ }
+ }
+}