8007464: Add graph inference support

Add support for more aggressive type-inference scheme

Reviewed-by: jjg

langtools/src/share/classes/com/sun/tools/javac/code/Source.java

@@ -221,7 +221,7 @@ public enum Source {
     public boolean allowIntersectionTypesInCast() {
         return compareTo(JDK1_8) >= 0;
     }
-    public boolean allowEarlyReturnConstraints() {
+    public boolean allowGraphInference() {
         return compareTo(JDK1_8) >= 0;
     }
     public boolean allowStructuralMostSpecific() {

langtools/src/share/classes/com/sun/tools/javac/comp/Attr.java

@@ -4152,7 +4152,9 @@ public class Attr extends JCTree.Visitor {
         }
 
     private Type capture(Type type) {
-        return types.capture(type);
+        //do not capture free types
+        return resultInfo.checkContext.inferenceContext().free(type) ?
+                type : types.capture(type);
     }
 
     private void validateTypeAnnotations(JCTree tree) {

langtools/src/share/classes/com/sun/tools/javac/comp/DeferredAttr.java

@@ -234,7 +234,7 @@ public class DeferredAttr extends JCTree.Visitor {
                     dt.speculativeCache.put(deferredAttrContext.msym, speculativeTree, deferredAttrContext.phase);
                     return speculativeTree.type;
                 case CHECK:
-                    Assert.check(dt.mode == AttrMode.SPECULATIVE);
+                    Assert.check(dt.mode != null);
                     return attr.attribTree(dt.tree, dt.env, resultInfo);
             }
             Assert.error();
@@ -242,6 +242,13 @@ public class DeferredAttr extends JCTree.Visitor {
         }
     };
 
+    DeferredTypeCompleter dummyCompleter = new DeferredTypeCompleter() {
+        public Type complete(DeferredType dt, ResultInfo resultInfo, DeferredAttrContext deferredAttrContext) {
+            Assert.check(deferredAttrContext.mode == AttrMode.CHECK);
+            return dt.tree.type = Type.noType;
+        }
+    };
+
     /**
      * The 'mode' in which the deferred type is to be type-checked
      */
@@ -382,7 +389,7 @@ public class DeferredAttr extends JCTree.Visitor {
                 if (!progress) {
                     //remove all variables that have already been instantiated
                     //from the list of stuck variables
-                    inferenceContext.solveAny(inferenceContext.freeVarsIn(List.from(stuckVars)));
+                    inferenceContext.solveAny(List.from(stuckVars), warn);
                     inferenceContext.notifyChange();
                 }
             }
@@ -431,7 +438,15 @@ public class DeferredAttr extends JCTree.Visitor {
                     return true;
                 case CHECK:
                     if (stuckVars.nonEmpty()) {
+                        //stuck expression - see if we can propagate
+                        if (deferredAttrContext.parent != emptyDeferredAttrContext &&
+                                Type.containsAny(deferredAttrContext.parent.inferenceContext.inferencevars, List.from(stuckVars))) {
+                            deferredAttrContext.parent.deferredAttrNodes.add(this);
+                            dt.check(resultInfo, List.<Type>nil(), dummyCompleter);
+                            return true;
+                        } else {
                             return false;
+                        }
                     } else {
                         dt.check(resultInfo, stuckVars, basicCompleter);
                         return true;

langtools/src/share/classes/com/sun/tools/javac/util/GraphUtils.java

@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 1999, 2013, 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.util;
+
+/** <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 GraphUtils {
+
+    /**
+     * This class is a basic abstract class for representing a node.
+     * A node is associated with a given data.
+     */
+    public static abstract class Node<D> {
+        public final D data;
+
+        public Node(D data) {
+            this.data = data;
+        }
+
+        public abstract Iterable<? extends Node<D>> getDependencies();
+
+        public abstract String printDependency(Node<D> to);
+
+        @Override
+        public String toString() {
+            return data.toString();
+        }
+    }
+
+    /**
+     * This class specialized Node, by adding elements that are required in order
+     * to perform Tarjan computation of strongly connected components.
+     */
+    public static abstract class TarjanNode<D> extends Node<D> implements Comparable<TarjanNode<D>> {
+        int index = -1;
+        int lowlink;
+        boolean active;
+
+        public TarjanNode(D data) {
+            super(data);
+        }
+
+        public abstract Iterable<? extends TarjanNode<D>> getDependencies();
+
+        public int compareTo(TarjanNode<D> o) {
+            return (index < o.index) ? -1 : (index == o.index) ? 0 : 1;
+        }
+    }
+
+    /**
+     * Tarjan's algorithm to determine strongly connected components of a
+     * directed graph in linear time. Works on TarjanNode.
+     */
+    public static <D, N extends TarjanNode<D>> List<? extends List<? extends N>> tarjan(Iterable<? extends N> nodes) {
+        ListBuffer<List<N>> cycles = ListBuffer.lb();
+        ListBuffer<N> stack = ListBuffer.lb();
+        int index = 0;
+        for (N node: nodes) {
+            if (node.index == -1) {
+                index += tarjan(node, index, stack, cycles);
+            }
+        }
+        return cycles.toList();
+    }
+
+    private static <D, N extends TarjanNode<D>> int tarjan(N v, int index, ListBuffer<N> stack, ListBuffer<List<N>> cycles) {
+        v.index = index;
+        v.lowlink = index;
+        index++;
+        stack.prepend(v);
+        v.active = true;
+        for (TarjanNode<D> nd: v.getDependencies()) {
+            @SuppressWarnings("unchecked")
+            N n = (N)nd;
+            if (n.index == -1) {
+                tarjan(n, index, stack, cycles);
+                v.lowlink = Math.min(v.lowlink, n.lowlink);
+            } else if (stack.contains(n)) {
+                v.lowlink = Math.min(v.lowlink, n.index);
+            }
+        }
+        if (v.lowlink == v.index) {
+            N n;
+            ListBuffer<N> cycle = ListBuffer.lb();
+            do {
+                n = stack.remove();
+                n.active = false;
+                cycle.add(n);
+            } while (n != v);
+            cycles.add(cycle.toList());
+        }
+        return index;
+    }
+
+    /**
+     * Debugging: dot representation of a set of connected nodes. The resulting
+     * dot representation will use {@code Node.toString} to display node labels
+     * and {@code Node.printDependency} to display edge labels. The resulting
+     * representation is also customizable with a graph name and a header.
+     */
+    public static <D> String toDot(Iterable<? extends TarjanNode<D>> nodes, String name, String header) {
+        StringBuilder buf = new StringBuilder();
+        buf.append(String.format("digraph %s {\n", name));
+        buf.append(String.format("label = \"%s\";\n", header));
+        //dump nodes
+        for (TarjanNode<D> n : nodes) {
+            buf.append(String.format("%s [label = \"%s\"];\n", n.hashCode(), n.toString()));
+        }
+        //dump arcs
+        for (TarjanNode<D> from : nodes) {
+            for (TarjanNode<D> to : from.getDependencies()) {
+                buf.append(String.format("%s -> %s [label = \" %s \"];\n",
+                        from.hashCode(), to.hashCode(), from.printDependency(to)));
+            }
+        }
+        buf.append("}\n");
+        return buf.toString();
+    }
+}

langtools/test/tools/javac/6758789/T6758789b.out

@@ -1,4 +1,4 @@
-T6758789b.java:16:11: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), T6758789a.Foo, T6758789a.Foo<X>
+T6758789b.java:16:11: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), T6758789a.Foo, T6758789a.Foo<java.lang.Object>
 T6758789b.java:16:10: compiler.warn.unchecked.meth.invocation.applied: kindname.method, m, T6758789a.Foo<X>, T6758789a.Foo, kindname.class, T6758789a
 - compiler.err.warnings.and.werror
 1 error

langtools/test/tools/javac/Diagnostics/6799605/T6799605.out

@@ -1,4 +1,4 @@
-T6799605.java:17:9: compiler.err.cant.apply.symbols: kindname.method, m, T6799605<compiler.misc.type.captureof: 1, ?>,{(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>), (compiler.misc.inferred.do.not.conform.to.upper.bounds: compiler.misc.type.captureof: 1, ?, T6799605<compiler.misc.type.captureof: 1, ?>)),(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>,T6799605<T>), (compiler.misc.infer.arg.length.mismatch: T)),(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>,T6799605<T>,T6799605<T>), (compiler.misc.infer.arg.length.mismatch: T))}
+T6799605.java:17:9: compiler.err.cant.apply.symbols: kindname.method, m, T6799605<compiler.misc.type.captureof: 1, ?>,{(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>), (compiler.misc.incompatible.eq.upper.bounds: T, compiler.misc.type.captureof: 1, ?, T6799605<T>)),(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>,T6799605<T>), (compiler.misc.infer.arg.length.mismatch: T)),(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>,T6799605<T>,T6799605<T>), (compiler.misc.infer.arg.length.mismatch: T))}
 T6799605.java:18:9: compiler.err.cant.apply.symbols: kindname.method, m, T6799605<compiler.misc.type.captureof: 1, ?>,T6799605<compiler.misc.type.captureof: 2, ?>,{(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>), (compiler.misc.infer.arg.length.mismatch: T)),(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>,T6799605<T>), (compiler.misc.inferred.do.not.conform.to.eq.bounds: compiler.misc.type.captureof: 2, ?, compiler.misc.type.captureof: 2, ?,compiler.misc.type.captureof: 1, ?)),(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>,T6799605<T>,T6799605<T>), (compiler.misc.infer.arg.length.mismatch: T))}
 T6799605.java:19:9: compiler.err.cant.apply.symbols: kindname.method, m, T6799605<compiler.misc.type.captureof: 1, ?>,T6799605<compiler.misc.type.captureof: 2, ?>,T6799605<compiler.misc.type.captureof: 3, ?>,{(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>), (compiler.misc.infer.arg.length.mismatch: T)),(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>,T6799605<T>), (compiler.misc.infer.arg.length.mismatch: T)),(compiler.misc.inapplicable.method: kindname.method, T6799605, <T>m(T6799605<T>,T6799605<T>,T6799605<T>), (compiler.misc.inferred.do.not.conform.to.eq.bounds: compiler.misc.type.captureof: 3, ?, compiler.misc.type.captureof: 3, ?,compiler.misc.type.captureof: 2, ?,compiler.misc.type.captureof: 1, ?))}
 3 errors

langtools/test/tools/javac/diags/examples/CantApplyDiamond1.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 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
@@ -23,7 +23,7 @@
 
 // key: compiler.err.prob.found.req
 // key: compiler.misc.cant.apply.diamond.1
-// key: compiler.misc.inferred.do.not.conform.to.upper.bounds
+// key: compiler.misc.incompatible.eq.upper.bounds
 // key: compiler.misc.diamond
 
 class CantApplyDiamond1<X> {

langtools/test/tools/javac/diags/examples/InferredDoNotConformToEq.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 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
@@ -23,6 +23,7 @@
 
 // key: compiler.err.cant.apply.symbol
 // key: compiler.misc.inferred.do.not.conform.to.eq.bounds
+// options: -source 7 -Xlint:-options
 
 import java.util.*;
 

langtools/test/tools/javac/diags/examples/InferredDoNotConformToUpper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 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
@@ -23,6 +23,7 @@
 
 // key: compiler.err.cant.apply.symbol
 // key: compiler.misc.inferred.do.not.conform.to.upper.bounds
+// options: -source 7 -Xlint:-options
 
 import java.util.*;
 

langtools/test/tools/javac/diags/examples/WhereFreshTvar.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 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
@@ -24,7 +24,7 @@
 // key: compiler.misc.where.fresh.typevar
 // key: compiler.misc.where.description.typevar
 // key: compiler.err.prob.found.req
-// key: compiler.misc.inferred.do.not.conform.to.upper.bounds
+// key: compiler.misc.inconvertible.types
 // options: -XDdiags=where,simpleNames
 // run: simple
 
@@ -33,5 +33,5 @@ import java.util.*;
 class WhereFreshTvar {
     <T extends List<T>> T m() {}
 
-    { List<String> ls = m(); }
+    { Object o = (List<String>)m(); }
 }

langtools/test/tools/javac/generics/7015430/T7015430.out

@@ -1,14 +1,14 @@
-T7015430.java:41:15: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.lang.Iterable, java.lang.Iterable<E>
+T7015430.java:41:15: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.lang.Iterable, java.lang.Iterable<java.lang.Exception>
 T7015430.java:41:14: compiler.warn.unchecked.meth.invocation.applied: kindname.method, empty, java.lang.Iterable<E>, java.lang.Iterable, kindname.class, T7015430
 T7015430.java:50:42: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.lang.Iterable, java.lang.Iterable<java.lang.RuntimeException>
 T7015430.java:50:41: compiler.warn.unchecked.meth.invocation.applied: kindname.method, empty, java.lang.Iterable<E>, java.lang.Iterable, kindname.class, T7015430
-T7015430.java:68:22: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.lang.Iterable, java.lang.Iterable<E>
+T7015430.java:68:22: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.lang.Iterable, java.lang.Iterable<java.lang.Exception>
 T7015430.java:68:9: compiler.warn.unchecked.meth.invocation.applied: kindname.constructor, <init>, java.lang.Iterable<E>, java.lang.Iterable, kindname.class, T7015430
 T7015430.java:77:40: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.lang.Iterable, java.lang.Iterable<java.lang.RuntimeException>
 T7015430.java:77:9: compiler.warn.unchecked.meth.invocation.applied: kindname.constructor, <init>, java.lang.Iterable<E>, java.lang.Iterable, kindname.class, T7015430
 T7015430.java:104:41: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.lang.Iterable, java.lang.Iterable<java.lang.RuntimeException>
 T7015430.java:104:9: compiler.warn.unchecked.meth.invocation.applied: kindname.constructor, <init>, java.lang.Iterable<E>, java.lang.Iterable, kindname.class, T7015430
-T7015430.java:113:22: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.lang.Iterable, java.lang.Iterable<E>
+T7015430.java:113:22: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.lang.Iterable, java.lang.Iterable<java.lang.Exception>
 T7015430.java:113:9: compiler.warn.unchecked.meth.invocation.applied: kindname.constructor, <init>, java.lang.Iterable<E>, java.lang.Iterable, kindname.class, T7015430
 T7015430.java:41:14: compiler.err.unreported.exception.need.to.catch.or.throw: java.lang.Exception
 T7015430.java:68:9: compiler.err.unreported.exception.need.to.catch.or.throw: java.lang.Exception

langtools/test/tools/javac/generics/7151802/T7151802.out

@@ -1,5 +1,5 @@
 T7151802.java:14:31: compiler.warn.unchecked.meth.invocation.applied: kindname.method, get1, Z, T7151802.Foo, kindname.class, T7151802
-T7151802.java:22:31: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), T7151802.Foo, T7151802.Foo<Z>
+T7151802.java:22:31: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), T7151802.Foo, T7151802.Foo<java.lang.Object>
 T7151802.java:22:30: compiler.warn.unchecked.meth.invocation.applied: kindname.method, get3, T7151802.Foo<Z>, T7151802.Foo, kindname.class, T7151802
 T7151802.java:30:36: compiler.warn.unchecked.meth.invocation.applied: kindname.method, get5, compiler.misc.no.args, compiler.misc.no.args, kindname.class, T7151802
 T7151802.java:38:32: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), T7151802.Foo, T7151802.Foo<java.lang.String>

langtools/test/tools/javac/generics/diamond/neg/Neg06.out

@@ -1,2 +1,2 @@
-Neg06.java:16:37: compiler.err.prob.found.req: (compiler.misc.cant.apply.diamond.1: (compiler.misc.diamond: Neg06.CFoo), (compiler.misc.inferred.do.not.conform.to.upper.bounds: java.lang.String, java.lang.Number))
+Neg06.java:16:37: compiler.err.prob.found.req: (compiler.misc.cant.apply.diamond.1: (compiler.misc.diamond: Neg06.CFoo), (compiler.misc.incompatible.eq.upper.bounds: X, java.lang.String, java.lang.Number))
 1 error

langtools/test/tools/javac/generics/inference/6278587/T6278587Neg.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2013, 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
@@ -23,10 +23,11 @@
 
 /*
  * @test
- * @bug     6278587
+ * @bug     6278587 8007464
  * @summary Inference broken for subtypes of subtypes of F-bounded types
  * @author  Peter von der Ah\u00e9
- * @compile/fail T6278587Neg.java
+ * @compile/fail -source 7 T6278587Neg.java
+ * @compile T6278587Neg.java
  */
 
 public abstract class T6278587Neg {

langtools/test/tools/javac/generics/inference/6638712/T6638712d.out

@@ -1,2 +1,2 @@
-T6638712d.java:16:9: compiler.err.cant.apply.symbol: kindname.method, m, U,java.util.List<java.util.List<U>>, int,java.util.List<java.util.List<java.lang.String>>, kindname.class, T6638712d, (compiler.misc.inferred.do.not.conform.to.lower.bounds: java.lang.String, java.lang.Integer)
+T6638712d.java:16:9: compiler.err.cant.apply.symbol: kindname.method, m, U,java.util.List<java.util.List<U>>, int,java.util.List<java.util.List<java.lang.String>>, kindname.class, T6638712d, (compiler.misc.incompatible.eq.lower.bounds: U, java.lang.String, java.lang.Integer)
 1 error

langtools/test/tools/javac/generics/inference/6638712/T6638712e.out

@@ -1,2 +1,2 @@
-T6638712e.java:17:27: compiler.err.prob.found.req: (compiler.misc.inferred.do.not.conform.to.upper.bounds: java.lang.Object, java.lang.Boolean,java.lang.Object)
+T6638712e.java:17:27: compiler.err.prob.found.req: (compiler.misc.incompatible.eq.upper.bounds: X, java.lang.Object, java.lang.Boolean,java.lang.Object)
 1 error

langtools/test/tools/javac/generics/inference/7154127/T7154127.java

@@ -1,8 +1,9 @@
 /**
  * @test /nodynamiccopyright/
- * @bug 7154127
+ * @bug 7154127 8007464
  * @summary Inference cleanup: remove bound check analysis from visitors in Types.java
- * @compile/fail/ref=T7154127.out -XDrawDiagnostics T7154127.java
+ * @compile/fail/ref=T7154127.out -Xlint:-options -source 7 -XDrawDiagnostics T7154127.java
+ * @compile T7154127.java
  */
 class T7154127 {
 

langtools/test/tools/javac/generics/inference/7154127/T7154127.out

@@ -1,2 +1,2 @@
-T7154127.java:19:49: compiler.err.prob.found.req: (compiler.misc.incompatible.upper.bounds: Y, T7154127.B<U>,T7154127.D)
+T7154127.java:20:49: compiler.err.prob.found.req: (compiler.misc.incompatible.upper.bounds: Y, T7154127.B<U>,T7154127.D)
 1 error

langtools/test/tools/javac/generics/inference/7177306/T7177306a.out

@@ -1,4 +1,4 @@
-T7177306a.java:13:34: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.util.List, java.util.List<E>
+T7177306a.java:13:34: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), java.util.List, java.util.List<java.lang.Object>
 T7177306a.java:13:33: compiler.warn.unchecked.meth.invocation.applied: kindname.method, m, java.util.List<E>, java.util.List, kindname.class, T7177306a
 T7177306a.java:13:33: compiler.warn.prob.found.req: (compiler.misc.unchecked.assign), T7177306a, T7177306a<java.lang.Object>
 - compiler.err.warnings.and.werror

langtools/test/tools/javac/generics/inference/7177306/T7177306e.java

@@ -1,8 +1,9 @@
 /**
  * @test /nodynamiccopyright/
- * @bug 7177306
+ * @bug 7177306 8007464
  * @summary Regression: unchecked method call does not erase return type
- * @compile/fail/ref=T7177306e.out -XDrawDiagnostics T7177306e.java
+ * @compile/fail/ref=T7177306e.out -source 7 -Xlint:-options -XDrawDiagnostics T7177306e.java
+ * @compile/fail T7177306e.java
  */
 
 import java.util.List;

langtools/test/tools/javac/generics/inference/7177306/T7177306e.out

@@ -1,2 +1,2 @@
-T7177306e.java:15:9: compiler.err.prob.found.req: (compiler.misc.inferred.do.not.conform.to.upper.bounds: java.util.List<?>, java.util.List<compiler.misc.type.captureof: 1, ?>)
+T7177306e.java:16:9: compiler.err.prob.found.req: (compiler.misc.inferred.do.not.conform.to.upper.bounds: java.util.List<?>, java.util.List<compiler.misc.type.captureof: 1, ?>)
 1 error

langtools/test/tools/javac/generics/odersky/BadTest4.java

@@ -23,11 +23,12 @@
 
 /*
  * @test
- * @ bug
+ * @bug 8007464
  * @summary Negative regression test from odersky
  * @author odersky
  *
- * @compile/fail  BadTest4.java
+ * @compile/fail -source 7 BadTest4.java
+ * @compile BadTest4.java
  */
 
 class BadTest4 {

langtools/test/tools/javac/lambda/TargetType14.out

@@ -1,2 +1,2 @@
-TargetType14.java:20:29: compiler.err.prob.found.req: (compiler.misc.inferred.do.not.conform.to.lower.bounds: java.lang.Integer, java.lang.String)
+TargetType14.java:20:29: compiler.err.prob.found.req: (compiler.misc.incompatible.eq.lower.bounds: X, java.lang.Integer, java.lang.String)
 1 error

langtools/test/tools/javac/lambda/TargetType20.java

@@ -1,10 +1,33 @@
 /*
- * @test /nodynamiccopyright/
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8003280
  * @summary Add lambda tests
  *  complex case of lambda return type that depends on generic method
  *          inference variable
- * @compile/fail/ref=TargetType20.out -XDrawDiagnostics TargetType20.java
+ * @compile -XDrawDiagnostics TargetType20.java
  */
 import java.util.*;
 

langtools/test/tools/javac/lambda/TargetType20.out

@@ -1,2 +0,0 @@
-TargetType20.java:19:10: compiler.err.cant.apply.symbol: kindname.method, call, TargetType20.SAM2<Z>,TargetType20.SAM2<Z>, @428,@459, kindname.class, TargetType20.Test, (compiler.misc.inferred.do.not.conform.to.eq.bounds: java.lang.String, java.lang.String,java.lang.Object)
-1 error

langtools/test/tools/javac/lambda/TargetType28.out

@@ -1,3 +1,2 @@
-TargetType28.java:20:32: compiler.err.prob.found.req: (compiler.misc.inferred.do.not.conform.to.eq.bounds: java.lang.Number, java.lang.Number,java.lang.String)
+TargetType28.java:20:32: compiler.err.prob.found.req: (compiler.misc.incompatible.eq.upper.bounds: X, java.lang.String,X, java.lang.Object,java.lang.Number)
-TargetType28.java:21:33: compiler.err.prob.found.req: (compiler.misc.inferred.do.not.conform.to.eq.bounds: java.lang.Number, java.lang.Number,java.lang.Integer)
+1 error
-2 errors

langtools/test/tools/javac/lambda/TargetType50.java

@@ -1,9 +1,32 @@
 /*
- * @test /nodynamiccopyright/
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8003280
  * @summary Add lambda tests
  *  bad stuck check for method reference leads to javac crash
- * @compile/fail/ref=TargetType50.out -XDrawDiagnostics TargetType50.java
+ * @compile TargetType50.java
  */
 import java.util.*;
 
@@ -17,7 +40,7 @@ class TargetType50 {
         static <Z> Sink<Z> make() { return null; }
     }
 
-    <Y, S extends Sink<Y>> List<Y> m(Factory<S> factory) {  }
+    <Y, S extends Sink<Y>> List<Y> m(Factory<S> factory) { return null; }
 
     void test() {
         List<?> l1 = m(Sink::new);

langtools/test/tools/javac/lambda/TargetType50.out

@@ -1,3 +0,0 @@
-TargetType50.java:25:28: compiler.err.prob.found.req: (compiler.misc.inferred.do.not.conform.to.upper.bounds: TargetType50.Sink<java.lang.Object>, TargetType50.Sink<java.lang.String>)
-TargetType50.java:26:28: compiler.err.prob.found.req: (compiler.misc.inferred.do.not.conform.to.upper.bounds: TargetType50.Sink<java.lang.Object>, TargetType50.Sink<java.lang.String>)
-2 errors

langtools/test/tools/javac/lambda/TargetType51.java

@@ -23,7 +23,9 @@
 
 /*
  * @test
- * @summary smoke test for combinator-like stuck analysis
+ * @bug 8005244
+ * @summary Implement overload resolution as per latest spec EDR
+ *          smoke test for combinator-like stuck analysis
  * @author  Maurizio Cimadamore
  * @compile TargetType51.java
  */

langtools/test/tools/javac/lambda/TargetType52.java

@@ -1,6 +1,8 @@
 /*
  * @test /nodynamiccopyright/
- * @summary uncatched sam conversion failure exception lead to javac crash
+ * @bug 8005244
+ * @summary Implement overload resolution as per latest spec EDR
+ *          uncatched sam conversion failure exception lead to javac crash
  * @compile/fail/ref=TargetType52.out -XDrawDiagnostics TargetType52.java
  */
 class TargetType52 {

langtools/test/tools/javac/lambda/TargetType52.out

@@ -1,2 +1,2 @@
-TargetType52.java:15:9: compiler.err.cant.apply.symbol: kindname.method, m, TargetType52.FI<? extends java.lang.CharSequence,? extends java.util.ArrayList<? extends java.lang.CharSequence>>, @444, kindname.class, TargetType52, (compiler.misc.no.conforming.assignment.exists: (compiler.misc.no.suitable.functional.intf.inst: TargetType52.FI<java.lang.CharSequence,java.util.ArrayList<? extends java.lang.CharSequence>>))
+TargetType52.java:17:9: compiler.err.cant.apply.symbol: kindname.method, m, TargetType52.FI<? extends java.lang.CharSequence,? extends java.util.ArrayList<? extends java.lang.CharSequence>>, @525, kindname.class, TargetType52, (compiler.misc.no.conforming.assignment.exists: (compiler.misc.no.suitable.functional.intf.inst: TargetType52.FI<java.lang.CharSequence,java.util.ArrayList<? extends java.lang.CharSequence>>))
 1 error

langtools/test/tools/javac/lambda/TargetType53.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8007464
+ * @summary Add graph inference support
+ *          smoke test for graph inference
+ * @ignore  awaits stream API: 800NNNN
+ * @compile TargetType53.java
+ */
+import java.util.*;
+import java.util.stream.*;
+import java.util.function.*;
+
+class TargetType53 {
+
+    <P> List<List<P>> perm(List<P> l) { return null; }
+
+    void g(List<List<UnaryOperator<IntStream>>> l) { }
+
+    void test() {
+        List<List<UnaryOperator<IntStream>>> l =
+            perm(Arrays.asList(s -> s.sorted()));
+        g(perm(Arrays.asList(s -> s.sorted())));
+    }
+}

langtools/test/tools/javac/lambda/TargetType54.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8007464
+ * @summary Add graph inference support
+ *          smoke test for graph inference
+ * @ignore  awaits stream API: 800NNNN
+ * @compile TargetType54.java
+ */
+import java.util.stream.*;
+import java.util.*;
+import static java.util.stream.Collectors.*;
+
+class TargetType54 {
+    void test(Stream<Integer> si) {
+        List<Integer> l1 = si.collect(toList());
+        List<Integer> l2 = si.collect(toCollection(ArrayList::new));
+        m(si.collect(toList()));
+        m(si.collect(toCollection(ArrayList::new)));
+    }
+
+    void m(List<Integer> l) { }
+}

langtools/test/tools/javac/lambda/TargetType55.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8007464
+ * @summary Add graph inference
+ *          support smoke test for graph inference
+ * @compile TargetType55.java
+ */
+import java.util.function.*;
+
+class TargetType55  {
+
+    <R> void m(Function<Integer, R> collector) { }
+
+    <T, D> Function<T, Integer> g(D d, BinaryOperator<D> reducer) { return null; }
+
+    public void test() {
+        m(g((Integer)null, (x,y)->1));
+    }
+}

langtools/test/tools/javac/lambda/TargetType56.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8007464
+ * @summary Add graph inference support
+ *          smoke test for graph inference
+ * @compile TargetType56.java
+ */
+class TargetType56 {
+    <Z> Z m(Z z) { return null; }
+
+    void test() {
+        double d1 = m(1);
+        double d2 = m((Integer)null);
+        double d3 = m(m(1));
+        double d4 = m(m((Integer)null));
+    }
+}

langtools/test/tools/javac/lambda/TargetType57.java

@@ -0,0 +1,20 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8007464
+ * @summary Add graph inference support
+ *          more smoke tests for graph inference
+ * @compile/fail/ref=TargetType57.out -XDrawDiagnostics TargetType57.java
+ */
+import java.util.*;
+import java.util.function.*;
+
+class TargetType57 {
+
+    void test(List<Integer> list) {
+        m(list, s -> s.intValue(), s -> s.nonExistentMethod());
+    }
+
+    <U, R, S_IN, S_OUT> R m(List<S_IN> list,
+                        Function<S_IN, S_OUT> f1,
+                        Function<S_OUT, R> f2) { return null; }
+}

langtools/test/tools/javac/lambda/TargetType57.out

@@ -0,0 +1,2 @@
+TargetType57.java:14:42: compiler.err.cant.resolve.location.args: kindname.method, nonExistentMethod, , , (compiler.misc.location.1: kindname.variable, s, java.lang.Integer)
+1 error

langtools/test/tools/javac/lambda/TargetType58.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8007464
+ * @summary Add graph inference support
+ *          more smoke tests for graph inference
+ * @ignore  awaits stream API: 800NNNN
+ * @compile TargetType58.java
+ */
+import java.util.*;
+import java.util.function.*;
+import java.util.stream.*;
+
+class TargetType58 {
+
+    void test(List<Integer> li) {
+        g(li, s -> s.substream(200), Collections.emptyList());
+    }
+
+    <T, U, S_OUT extends Stream<U>,
+            I extends Iterable<U>> Collection<U> g(Collection<T> coll, Function<Stream<T>, S_OUT> f, I i) {
+        return null;
+    }
+}

langtools/test/tools/javac/lambda/TargetType59.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8007464
+ * @summary Add graph inference support
+ *          more smoke tests for graph inference
+ * @ignore  awaits stream API: 800NNNN
+ * @compile TargetType59.java
+ */
+import java.util.*;
+import java.util.function.*;
+import java.util.stream.*;
+
+class TargetType59 {
+
+    <T, R> Collector<T, R> m(Supplier<? extends R> supplier, BiConsumer<R, T> accumulator) {
+        return null;
+    }
+
+    <T, C extends Collection<T>> Collector<T,C> test1(Supplier<C> collectionFactory) {
+        return m(collectionFactory, Collection::add);
+    }
+
+    Collector<String, StringBuilder> test2(Supplier<StringBuilder> sb) {
+        return m(sb, StringBuilder::append);
+    }
+}

langtools/test/tools/javac/lambda/TargetType61.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8007464
+ * @summary Add graph inference support
+ *          check that new wildcards inference strategy doesn't run into 7190296
+ * @compile TargetType61.java
+ */
+class TargetType61 {
+
+    interface Stream<T> {
+        void forEach(Sink<? super T> sink);
+    }
+
+    interface Sink<T> {
+        void put(T t);
+    }
+
+    public boolean add(CharSequence s) { return false; }
+
+    public void addAll(Stream<? extends CharSequence> stream) {
+        stream.forEach(this::add);
+        stream.forEach(e -> { add(e); });
+    }
+}

langtools/test/tools/javac/lambda/TargetType62.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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 8007464
+ * @summary Add graph inference support
+ *          check that new wildcards inference strategy doesn't run into 7190296
+ * @ignore  awaits stream API: 800NNNN
+ * @compile TargetType62.java
+ */
+import java.util.*;
+import java.util.function.*;
+import java.util.stream.*;
+
+class TargetType61 {
+
+    Collector test(Function<Integer, Integer> classifier) {
+        return g(classifier, TreeMap::new, m(HashSet::new));
+    }
+
+    <R> Collector<Integer, R> m(Supplier<R> s) { return null; }
+
+    <T, K, D, M extends Map<K, D>>
+            Collector<T, M> g(Function<T, K> classifier, Supplier<M> mapFactory, Collector<T, D> downstream) { return null; }
+}