--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Infer.java Thu Nov 12 14:13:17 2015 -0800
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Infer.java Fri Nov 13 12:29:23 2015 +0000
@@ -182,6 +182,7 @@
argtypes, mt.getParameterTypes(), warn);
if (allowGraphInference && resultInfo != null && resultInfo.pt == anyPoly) {
+ checkWithinBounds(inferenceContext, warn);
//we are inside method attribution - just return a partially inferred type
return new PartiallyInferredMethodType(mt, inferenceContext, env, warn);
} else if (allowGraphInference &&
@@ -189,13 +190,21 @@
!warn.hasNonSilentLint(Lint.LintCategory.UNCHECKED)) {
//inject return constraints earlier
checkWithinBounds(inferenceContext, warn); //propagation
+
+ boolean shouldPropagate = resultInfo.checkContext.inferenceContext().free(resultInfo.pt);
+
+ InferenceContext minContext = shouldPropagate ?
+ inferenceContext.min(roots(mt, deferredAttrContext), true, warn) :
+ inferenceContext;
+
Type newRestype = generateReturnConstraints(env.tree, resultInfo, //B3
- mt, inferenceContext);
+ mt, minContext);
mt = (MethodType)types.createMethodTypeWithReturn(mt, newRestype);
+
//propagate outwards if needed
- if (resultInfo.checkContext.inferenceContext().free(resultInfo.pt)) {
+ if (shouldPropagate) {
//propagate inference context outwards and exit
- inferenceContext.dupTo(resultInfo.checkContext.inferenceContext());
+ minContext.dupTo(resultInfo.checkContext.inferenceContext());
deferredAttrContext.complete();
return mt;
}
@@ -242,6 +251,19 @@
dumpGraphsIfNeeded(env.tree, msym, resolveContext);
}
}
+ //where
+ private List<Type> roots(MethodType mt, DeferredAttrContext deferredAttrContext) {
+ ListBuffer<Type> roots = new ListBuffer<>();
+ roots.add(mt.getReturnType());
+ if (deferredAttrContext != null && deferredAttrContext.mode == AttrMode.CHECK) {
+ roots.addAll(mt.getThrownTypes());
+ for (DeferredAttr.DeferredAttrNode n : deferredAttrContext.deferredAttrNodes) {
+ roots.addAll(n.deferredStuckPolicy.stuckVars());
+ roots.addAll(n.deferredStuckPolicy.depVars());
+ }
+ }
+ return roots.toList();
+ }
/**
* A partially infered method/constructor type; such a type can be checked multiple times
@@ -284,16 +306,21 @@
*/
saved_undet = inferenceContext.save();
if (allowGraphInference && !warn.hasNonSilentLint(Lint.LintCategory.UNCHECKED)) {
- //inject return constraints earlier
- checkWithinBounds(inferenceContext, noWarnings); //propagation
- Type res = generateReturnConstraints(env.tree, resultInfo, //B3
- this, inferenceContext);
+ boolean shouldPropagate = resultInfo.checkContext.inferenceContext().free(resultInfo.pt);
+
+ InferenceContext minContext = shouldPropagate ?
+ inferenceContext.min(roots(asMethodType(), null), false, warn) :
+ inferenceContext;
- if (resultInfo.checkContext.inferenceContext().free(resultInfo.pt)) {
+ MethodType other = (MethodType)minContext.update(asMethodType());
+ Type newRestype = generateReturnConstraints(env.tree, resultInfo, //B3
+ other, minContext);
+
+ if (shouldPropagate) {
//propagate inference context outwards and exit
- inferenceContext.dupTo(resultInfo.checkContext.inferenceContext(),
+ minContext.dupTo(resultInfo.checkContext.inferenceContext(),
resultInfo.checkContext.deferredAttrContext().insideOverloadPhase());
- return res;
+ return newRestype;
}
}
inferenceContext.solve(noWarnings);
@@ -589,6 +616,18 @@
}
}
+ TypeMapping<Void> fromTypeVarFun = new TypeMapping<Void>() {
+ @Override
+ public Type visitTypeVar(TypeVar tv, Void aVoid) {
+ return new UndetVar(tv, types);
+ }
+
+ @Override
+ public Type visitCapturedType(CapturedType t, Void aVoid) {
+ return new CapturedUndetVar(t, types);
+ }
+ };
+
/**
* This method is used to infer a suitable target SAM in case the original
* SAM type contains one or more wildcards. An inference process is applied
--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/InferenceContext.java Thu Nov 12 14:13:17 2015 -0800
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/InferenceContext.java Fri Nov 13 12:29:23 2015 +0000
@@ -25,39 +25,35 @@
package com.sun.tools.javac.comp;
+import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
+import java.util.HashSet;
import java.util.Map;
import java.util.Set;
-import com.sun.tools.javac.code.Symtab;
import com.sun.tools.javac.code.Type;
-import com.sun.tools.javac.code.Type.CapturedType;
-import com.sun.tools.javac.code.Type.CapturedUndetVar;
-import com.sun.tools.javac.code.Type.TypeMapping;
+import com.sun.tools.javac.code.Type.ArrayType;
+import com.sun.tools.javac.code.Type.ClassType;
import com.sun.tools.javac.code.Type.TypeVar;
import com.sun.tools.javac.code.Type.UndetVar;
import com.sun.tools.javac.code.Type.UndetVar.InferenceBound;
+import com.sun.tools.javac.code.Type.WildcardType;
import com.sun.tools.javac.code.Types;
-import com.sun.tools.javac.comp.Infer.BestLeafSolver;
import com.sun.tools.javac.comp.Infer.FreeTypeListener;
import com.sun.tools.javac.comp.Infer.GraphSolver;
import com.sun.tools.javac.comp.Infer.GraphStrategy;
import com.sun.tools.javac.comp.Infer.InferenceException;
import com.sun.tools.javac.comp.Infer.InferenceStep;
-import com.sun.tools.javac.comp.Infer.LeafSolver;
import com.sun.tools.javac.tree.JCTree;
-import com.sun.tools.javac.tree.TreeMaker;
import com.sun.tools.javac.util.Assert;
-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.Factory;
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.Warner;
+import static com.sun.tools.javac.code.TypeTag.UNDETVAR;
+
/**
* An inference context keeps track of the set of variables that are free
* in the current context. It provides utility methods for opening/closing
@@ -76,43 +72,34 @@
/** list of inference vars as undet vars */
List<Type> undetvars;
+ Type update(Type t) {
+ return t;
+ }
+
/** list of inference vars in this context */
List<Type> inferencevars;
Map<FreeTypeListener, List<Type>> freeTypeListeners = new HashMap<>();
- List<FreeTypeListener> freetypeListeners = List.nil();
-
Types types;
Infer infer;
public InferenceContext(Infer infer, List<Type> inferencevars) {
+ this(infer, inferencevars, inferencevars.map(infer.fromTypeVarFun));
+ }
+
+ public InferenceContext(Infer infer, List<Type> inferencevars, List<Type> undetvars) {
this.inferencevars = inferencevars;
-
+ this.undetvars = undetvars;
this.infer = infer;
this.types = infer.types;
-
- fromTypeVarFun = new TypeMapping<Void>() {
- @Override
- public Type visitTypeVar(TypeVar tv, Void aVoid) {
- return new UndetVar(tv, types);
- }
-
- @Override
- public Type visitCapturedType(CapturedType t, Void aVoid) {
- return new CapturedUndetVar(t, types);
- }
- };
- this.undetvars = inferencevars.map(fromTypeVarFun);
}
- TypeMapping<Void> fromTypeVarFun;
-
/**
* add a new inference var to this inference context
*/
void addVar(TypeVar t) {
- this.undetvars = this.undetvars.prepend(fromTypeVarFun.apply(t));
+ this.undetvars = this.undetvars.prepend(infer.fromTypeVarFun.apply(t));
this.inferencevars = this.inferencevars.prepend(t);
}
@@ -366,6 +353,124 @@
}
}
+ InferenceContext min(List<Type> roots, boolean shouldSolve, Warner warn) {
+ ReachabilityVisitor rv = new ReachabilityVisitor();
+ rv.scan(roots);
+ if (rv.min.size() == inferencevars.length()) {
+ return this;
+ }
+
+ List<Type> minVars = List.from(rv.min);
+ List<Type> redundantVars = inferencevars.diff(minVars);
+
+ //compute new undet variables (bounds associated to redundant variables are dropped)
+ ListBuffer<Type> minUndetVars = new ListBuffer<>();
+ for (Type minVar : minVars) {
+ UndetVar uv = (UndetVar)asUndetVar(minVar);
+ UndetVar uv2 = new UndetVar((TypeVar)minVar, types);
+ for (InferenceBound ib : InferenceBound.values()) {
+ List<Type> newBounds = uv.getBounds(ib).stream()
+ .filter(b -> !redundantVars.contains(b))
+ .collect(List.collector());
+ uv2.setBounds(ib, newBounds);
+ }
+ minUndetVars.add(uv2);
+ }
+
+ //compute new minimal inference context
+ InferenceContext minContext = new InferenceContext(infer, minVars, minUndetVars.toList());
+ for (Type t : minContext.inferencevars) {
+ //add listener that forwards notifications to original context
+ minContext.addFreeTypeListener(List.of(t), (inferenceContext) -> {
+ List<Type> depVars = List.from(rv.minMap.get(t));
+ solve(depVars, warn);
+ notifyChange();
+ });
+ }
+ if (shouldSolve) {
+ //solve definitively unreachable variables
+ List<Type> unreachableVars = redundantVars.diff(List.from(rv.equiv));
+ solve(unreachableVars, warn);
+ }
+ return minContext;
+ }
+
+ class ReachabilityVisitor extends Types.UnaryVisitor<Void> {
+
+ Set<Type> equiv = new HashSet<>();
+ Set<Type> min = new HashSet<>();
+ Map<Type, Set<Type>> minMap = new HashMap<>();
+
+ void scan(List<Type> roots) {
+ roots.stream().forEach(this::visit);
+ }
+
+ @Override
+ public Void visitType(Type t, Void _unused) {
+ return null;
+ }
+
+ @Override
+ public Void visitUndetVar(UndetVar t, Void _unused) {
+ if (min.add(t.qtype)) {
+ Set<Type> deps = minMap.getOrDefault(t.qtype, new HashSet<>(Collections.singleton(t.qtype)));
+ for (Type b : t.getBounds(InferenceBound.values())) {
+ Type undet = asUndetVar(b);
+ if (!undet.hasTag(UNDETVAR)) {
+ visit(undet);
+ } else if (isEquiv((UndetVar)undet, b)){
+ deps.add(b);
+ equiv.add(b);
+ } else {
+ visit(undet);
+ }
+ }
+ minMap.put(t.qtype, deps);
+ }
+ return null;
+ }
+
+ @Override
+ public Void visitWildcardType(WildcardType t, Void _unused) {
+ return visit(t.type);
+ }
+
+ @Override
+ public Void visitTypeVar(TypeVar t, Void aVoid) {
+ Type undet = asUndetVar(t);
+ if (undet.hasTag(UNDETVAR)) {
+ visitUndetVar((UndetVar)undet, null);
+ }
+ return null;
+ }
+
+ @Override
+ public Void visitArrayType(ArrayType t, Void _unused) {
+ return visit(t.elemtype);
+ }
+
+ @Override
+ public Void visitClassType(ClassType t, Void _unused) {
+ visit(t.getEnclosingType());
+ for (Type targ : t.getTypeArguments()) {
+ visit(targ);
+ }
+ return null;
+ }
+
+ boolean isEquiv(UndetVar from, Type t) {
+ UndetVar uv = (UndetVar)asUndetVar(t);
+ for (InferenceBound ib : InferenceBound.values()) {
+ List<Type> b1 = uv.getBounds(ib);
+ List<Type> b2 = from.getBounds(ib);
+ if (!b1.containsAll(b2) || !b2.containsAll(b1)) {
+ return false;
+ }
+ }
+ return true;
+ }
+ }
+
private void solve(GraphStrategy ss, Warner warn) {
solve(ss, new HashMap<Type, Set<Type>>(), warn);
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/lambda/speculative/T8046685.java Fri Nov 13 12:29:23 2015 +0000
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2015, 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.
+ */
+
+/*
+ * @test
+ * @bug 8046685
+ * @summary Uncompilable large expressions involving generics.
+ * @compile T8046685.java
+ */
+class T8046685 {
+
+ interface Predicate<T, U> {
+ public boolean apply(T t, U u);
+ public boolean equals(Object o);
+ }
+
+ static <X1, X2> Predicate<X1, X2> and(final Predicate<? super X1, ? super X2> first, final Predicate<? super X1, ? super X2> second) {
+ return null;
+ }
+
+ public static void test(Predicate<Integer, Integer> even) {
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even,
+ and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, and(even, even)
+ ))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
+ )))))))))))))))))))))))))))))))))));
+ }
+}