diff -r 0ea78d6e0b7b -r b4b0377b8dba langtools/src/share/classes/com/sun/tools/javac/comp/DeferredAttr.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/DeferredAttr.java	Thu Oct 04 13:04:53 2012 +0100
@@ -0,0 +1,553 @@
+/*
+ * Copyright (c) 2012, 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.*;
+import com.sun.tools.javac.tree.*;
+import com.sun.tools.javac.util.*;
+import com.sun.tools.javac.code.Symbol.*;
+import com.sun.tools.javac.code.Type.*;
+import com.sun.tools.javac.comp.Attr.ResultInfo;
+import com.sun.tools.javac.comp.Infer.InferenceContext;
+import com.sun.tools.javac.comp.Resolve.MethodResolutionPhase;
+import com.sun.tools.javac.tree.JCTree.*;
+
+import javax.tools.JavaFileObject;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Queue;
+import java.util.Set;
+import java.util.WeakHashMap;
+
+import static com.sun.tools.javac.code.TypeTags.*;
+import static com.sun.tools.javac.tree.JCTree.Tag.*;
+import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
+
+/**
+ * This is an helper class that is used to perform deferred type-analysis.
+ * Each time a poly expression occurs in argument position, javac attributes it
+ * with a temporary 'deferred type' that is checked (possibly multiple times)
+ * against an expected formal type.
+ *
+ *  <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 DeferredAttr extends JCTree.Visitor {
+    protected static final Context.Key<DeferredAttr> deferredAttrKey =
+        new Context.Key<DeferredAttr>();
+
+    final Attr attr;
+    final Check chk;
+    final Enter enter;
+    final Infer infer;
+    final Log log;
+    final Symtab syms;
+    final TreeMaker make;
+    final Types types;
+
+    public static DeferredAttr instance(Context context) {
+        DeferredAttr instance = context.get(deferredAttrKey);
+        if (instance == null)
+            instance = new DeferredAttr(context);
+        return instance;
+    }
+
+    protected DeferredAttr(Context context) {
+        context.put(deferredAttrKey, this);
+        attr = Attr.instance(context);
+        chk = Check.instance(context);
+        enter = Enter.instance(context);
+        infer = Infer.instance(context);
+        log = Log.instance(context);
+        syms = Symtab.instance(context);
+        make = TreeMaker.instance(context);
+        types = Types.instance(context);
+    }
+
+    /**
+     * This type represents a deferred type. A deferred type starts off with
+     * no information on the underlying expression type. Such info needs to be
+     * discovered through type-checking the deferred type against a target-type.
+     * Every deferred type keeps a pointer to the AST node from which it originated.
+     */
+    public class DeferredType extends Type {
+
+        public JCExpression tree;
+        Env<AttrContext> env;
+        AttrMode mode;
+        SpeculativeCache speculativeCache;
+
+        DeferredType(JCExpression tree, Env<AttrContext> env) {
+            super(DEFERRED, null);
+            this.tree = tree;
+            this.env = env.dup(tree, env.info.dup());
+            this.speculativeCache = new SpeculativeCache();
+        }
+
+        /**
+         * A speculative cache is used to keep track of all overload resolution rounds
+         * that triggered speculative attribution on a given deferred type. Each entry
+         * stores a pointer to the speculative tree and the resolution phase in which the entry
+         * has been added.
+         */
+        class SpeculativeCache {
+
+            private Map<Symbol, List<Entry>> cache =
+                    new WeakHashMap<Symbol, List<Entry>>();
+
+            class Entry {
+                JCTree speculativeTree;
+                Resolve.MethodResolutionPhase phase;
+
+                public Entry(JCTree speculativeTree, MethodResolutionPhase phase) {
+                    this.speculativeTree = speculativeTree;
+                    this.phase = phase;
+                }
+
+                boolean matches(Resolve.MethodResolutionPhase phase) {
+                    return this.phase == phase;
+                }
+            }
+
+            /**
+             * Clone a speculative cache entry as a fresh entry associated
+             * with a new method (this maybe required to fixup speculative cache
+             * misses after Resolve.access())
+             */
+            void dupAllTo(Symbol from, Symbol to) {
+                Assert.check(cache.get(to) == null);
+                List<Entry> entries = cache.get(from);
+                if (entries != null) {
+                    cache.put(to, entries);
+                }
+            }
+
+            /**
+             * Retrieve a speculative cache entry corresponding to given symbol
+             * and resolution phase
+             */
+            Entry get(Symbol msym, MethodResolutionPhase phase) {
+                List<Entry> entries = cache.get(msym);
+                if (entries == null) return null;
+                for (Entry e : entries) {
+                    if (e.matches(phase)) return e;
+                }
+                return null;
+            }
+
+            /**
+             * Stores a speculative cache entry corresponding to given symbol
+             * and resolution phase
+             */
+            void put(Symbol msym, JCTree speculativeTree, MethodResolutionPhase phase) {
+                List<Entry> entries = cache.get(msym);
+                if (entries == null) {
+                    entries = List.nil();
+                }
+                cache.put(msym, entries.prepend(new Entry(speculativeTree, phase)));
+            }
+        }
+
+        /**
+         * Get the type that has been computed during a speculative attribution round
+         */
+        Type speculativeType(Symbol msym, MethodResolutionPhase phase) {
+            SpeculativeCache.Entry e = speculativeCache.get(msym, phase);
+            return e != null ? e.speculativeTree.type : Type.noType;
+        }
+
+        /**
+         * Check a deferred type against a potential target-type. Depending on
+         * the current attribution mode, a normal vs. speculative attribution
+         * round is performed on the underlying AST node. There can be only one
+         * speculative round for a given target method symbol; moreover, a normal
+         * attribution round must follow one or more speculative rounds.
+         */
+        Type check(ResultInfo resultInfo) {
+            DeferredAttrContext deferredAttrContext =
+                    resultInfo.checkContext.deferredAttrContext();
+            Assert.check(deferredAttrContext != emptyDeferredAttrContext);
+            List<Type> stuckVars = stuckVars(tree, resultInfo);
+            if (stuckVars.nonEmpty()) {
+                deferredAttrContext.addDeferredAttrNode(this, resultInfo, stuckVars);
+                return Type.noType;
+            } else {
+                try {
+                    switch (deferredAttrContext.mode) {
+                        case SPECULATIVE:
+                            Assert.check(mode == null ||
+                                    (mode == AttrMode.SPECULATIVE &&
+                                    speculativeType(deferredAttrContext.msym, deferredAttrContext.phase).tag == NONE));
+                            JCTree speculativeTree = attribSpeculative(tree, env, resultInfo);
+                            speculativeCache.put(deferredAttrContext.msym, speculativeTree, deferredAttrContext.phase);
+                            return speculativeTree.type;
+                        case CHECK:
+                            Assert.check(mode == AttrMode.SPECULATIVE);
+                            return attr.attribTree(tree, env, resultInfo);
+                    }
+                    Assert.error();
+                    return null;
+                } finally {
+                    mode = deferredAttrContext.mode;
+                }
+            }
+        }
+    }
+
+    /**
+     * The 'mode' in which the deferred type is to be type-checked
+     */
+    public enum AttrMode {
+        /**
+         * A speculative type-checking round is used during overload resolution
+         * mainly to generate constraints on inference variables. Side-effects
+         * arising from type-checking the expression associated with the deferred
+         * type are reversed after the speculative round finishes. This means the
+         * expression tree will be left in a blank state.
+         */
+        SPECULATIVE,
+        /**
+         * This is the plain type-checking mode. Produces side-effects on the underlying AST node
+         */
+        CHECK;
+    }
+
+    /**
+     * Routine that performs speculative type-checking; the input AST node is
+     * cloned (to avoid side-effects cause by Attr) and compiler state is
+     * restored after type-checking. All diagnostics (but critical ones) are
+     * disabled during speculative type-checking.
+     */
+    JCTree attribSpeculative(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
+        JCTree newTree = new TreeCopier<Object>(make).copy(tree);
+        Env<AttrContext> speculativeEnv = env.dup(newTree, env.info.dup(env.info.scope.dupUnshared()));
+        speculativeEnv.info.scope.owner = env.info.scope.owner;
+        Filter<JCDiagnostic> prevDeferDiagsFilter = log.deferredDiagFilter;
+        Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
+        final JavaFileObject currentSource = log.currentSourceFile();
+        try {
+            log.deferredDiagnostics = new ListBuffer<JCDiagnostic>();
+            log.deferredDiagFilter = new Filter<JCDiagnostic>() {
+                public boolean accepts(JCDiagnostic t) {
+                    return t.getDiagnosticSource().getFile().equals(currentSource);
+                }
+            };
+            attr.attribTree(newTree, speculativeEnv, resultInfo);
+            unenterScanner.scan(newTree);
+            return newTree;
+        } catch (Abort ex) {
+            //if some very bad condition occurred during deferred attribution
+            //we should dump all errors before killing javac
+            log.reportDeferredDiagnostics();
+            throw ex;
+        } finally {
+            unenterScanner.scan(newTree);
+            log.deferredDiagFilter = prevDeferDiagsFilter;
+            log.deferredDiagnostics = prevDeferredDiags;
+        }
+    }
+    //where
+        protected TreeScanner unenterScanner = new TreeScanner() {
+            @Override
+            public void visitClassDef(JCClassDecl tree) {
+                ClassSymbol csym = tree.sym;
+                enter.typeEnvs.remove(csym);
+                chk.compiled.remove(csym.flatname);
+                syms.classes.remove(csym.flatname);
+                super.visitClassDef(tree);
+            }
+        };
+
+    /**
+     * A deferred context is created on each method check. A deferred context is
+     * used to keep track of information associated with the method check, such as
+     * the symbol of the method being checked, the overload resolution phase,
+     * the kind of attribution mode to be applied to deferred types and so forth.
+     * As deferred types are processed (by the method check routine) stuck AST nodes
+     * are added (as new deferred attribution nodes) to this context. The complete()
+     * routine makes sure that all pending nodes are properly processed, by
+     * progressively instantiating all inference variables on which one or more
+     * deferred attribution node is stuck.
+     */
+    class DeferredAttrContext {
+
+        /** attribution mode */
+        final AttrMode mode;
+
+        /** symbol of the method being checked */
+        final Symbol msym;
+
+        /** method resolution step */
+        final Resolve.MethodResolutionPhase phase;
+
+        /** inference context */
+        final InferenceContext inferenceContext;
+
+        /** list of deferred attribution nodes to be processed */
+        ArrayList<DeferredAttrNode> deferredAttrNodes = new ArrayList<DeferredAttrNode>();
+
+        DeferredAttrContext(AttrMode mode, Symbol msym, MethodResolutionPhase phase, InferenceContext inferenceContext) {
+            this.mode = mode;
+            this.msym = msym;
+            this.phase = phase;
+            this.inferenceContext = inferenceContext;
+        }
+
+        /**
+         * Adds a node to the list of deferred attribution nodes - used by Resolve.rawCheckArgumentsApplicable
+         * Nodes added this way act as 'roots' for the out-of-order method checking process.
+         */
+        void addDeferredAttrNode(final DeferredType dt, ResultInfo resultInfo, List<Type> stuckVars) {
+            deferredAttrNodes.add(new DeferredAttrNode(dt, resultInfo, stuckVars));
+        }
+
+        /**
+         * Incrementally process all nodes, by skipping 'stuck' nodes and attributing
+         * 'unstuck' ones. If at any point no progress can be made (no 'unstuck' nodes)
+         * some inference variable might get eagerly instantiated so that all nodes
+         * can be type-checked.
+         */
+        void complete() {
+            while (!deferredAttrNodes.isEmpty()) {
+                Set<Type> stuckVars = new HashSet<Type>();
+                boolean progress = false;
+                //scan a defensive copy of the node list - this is because a deferred
+                //attribution round can add new nodes to the list
+                for (DeferredAttrNode deferredAttrNode : List.from(deferredAttrNodes)) {
+                    if (!deferredAttrNode.isStuck()) {
+                        deferredAttrNode.process();
+                        deferredAttrNodes.remove(deferredAttrNode);
+                        progress = true;
+                    } else {
+                        stuckVars.addAll(deferredAttrNode.stuckVars);
+                    }
+                }
+                if (!progress) {
+                    //remove all variables that have already been instantiated
+                    //from the list of stuck variables
+                    inferenceContext.solveAny(inferenceContext.freeVarsIn(List.from(stuckVars)), types, infer);
+                    inferenceContext.notifyChange(types);
+                }
+            }
+        }
+
+        /**
+         * Class representing a deferred attribution node. It keeps track of
+         * a deferred type, along with the expected target type information.
+         */
+        class DeferredAttrNode implements Infer.InferenceContext.FreeTypeListener {
+
+            /** underlying deferred type */
+            DeferredType dt;
+
+            /** underlying target type information */
+            ResultInfo resultInfo;
+
+            /** list of uninferred inference variables causing this node to be stuck */
+            List<Type> stuckVars;
+
+            DeferredAttrNode(DeferredType dt, ResultInfo resultInfo, List<Type> stuckVars) {
+                this.dt = dt;
+                this.resultInfo = resultInfo;
+                this.stuckVars = stuckVars;
+                if (!stuckVars.isEmpty()) {
+                    resultInfo.checkContext.inferenceContext().addFreeTypeListener(stuckVars, this);
+                }
+            }
+
+            @Override
+            public void typesInferred(InferenceContext inferenceContext) {
+                stuckVars = List.nil();
+                resultInfo = resultInfo.dup(inferenceContext.asInstType(resultInfo.pt, types));
+            }
+
+            /**
+             * is this node stuck?
+             */
+            boolean isStuck() {
+                return stuckVars.nonEmpty();
+            }
+
+            /**
+             * Process a deferred attribution node.
+             * Invariant: a stuck node cannot be processed.
+             */
+            void process() {
+                if (isStuck()) {
+                    throw new IllegalStateException("Cannot process a stuck deferred node");
+                }
+                dt.check(resultInfo);
+            }
+        }
+    }
+
+    /** an empty deferred attribution context - all methods throw exceptions */
+    final DeferredAttrContext emptyDeferredAttrContext =
+            new DeferredAttrContext(null, null, null, null) {
+                @Override
+                void addDeferredAttrNode(DeferredType dt, ResultInfo ri, List<Type> stuckVars) {
+                    Assert.error("Empty deferred context!");
+                }
+                @Override
+                void complete() {
+                    Assert.error("Empty deferred context!");
+                }
+            };
+
+    /**
+     * Map a list of types possibly containing one or more deferred types
+     * into a list of ordinary types. Each deferred type D is mapped into a type T,
+     * where T is computed by retrieving the type that has already been
+     * computed for D during a previous deferred attribution round of the given kind.
+     */
+    class DeferredTypeMap extends Type.Mapping {
+
+        DeferredAttrContext deferredAttrContext;
+
+        protected DeferredTypeMap(AttrMode mode, Symbol msym, MethodResolutionPhase phase) {
+            super(String.format("deferredTypeMap[%s]", mode));
+            this.deferredAttrContext = new DeferredAttrContext(mode, msym, phase, infer.emptyContext);
+        }
+
+        protected boolean validState(DeferredType dt) {
+            return dt.mode != null &&
+                    deferredAttrContext.mode.ordinal() <= dt.mode.ordinal();
+        }
+
+        @Override
+        public Type apply(Type t) {
+            if (t.tag != DEFERRED) {
+                return t.map(this);
+            } else {
+                DeferredType dt = (DeferredType)t;
+                Assert.check(validState(dt));
+                return typeOf(dt);
+            }
+        }
+
+        protected Type typeOf(DeferredType dt) {
+            switch (deferredAttrContext.mode) {
+                case CHECK:
+                    return dt.tree.type == null ? Type.noType : dt.tree.type;
+                case SPECULATIVE:
+                    return dt.speculativeType(deferredAttrContext.msym, deferredAttrContext.phase);
+            }
+            Assert.error();
+            return null;
+        }
+    }
+
+    /**
+     * Specialized recovery deferred mapping.
+     * Each deferred type D is mapped into a type T, where T is computed either by
+     * (i) retrieving the type that has already been computed for D during a previous
+     * attribution round (as before), or (ii) by synthesizing a new type R for D
+     * (the latter step is useful in a recovery scenario).
+     */
+    public class RecoveryDeferredTypeMap extends DeferredTypeMap {
+
+        public RecoveryDeferredTypeMap(AttrMode mode, Symbol msym, MethodResolutionPhase phase) {
+            super(mode, msym, phase);
+        }
+
+        @Override
+        protected Type typeOf(DeferredType dt) {
+            Type owntype = super.typeOf(dt);
+            return owntype.tag == NONE ?
+                        recover(dt) : owntype;
+        }
+
+        @Override
+        protected boolean validState(DeferredType dt) {
+            return true;
+        }
+
+        /**
+         * Synthesize a type for a deferred type that hasn't been previously
+         * reduced to an ordinary type. Functional deferred types and conditionals
+         * are mapped to themselves, in order to have a richer diagnostic
+         * representation. Remaining deferred types are attributed using
+         * a default expected type (j.l.Object).
+         */
+        private Type recover(DeferredType dt) {
+            dt.check(new RecoveryInfo());
+            switch (TreeInfo.skipParens(dt.tree).getTag()) {
+                case LAMBDA:
+                case REFERENCE:
+                case CONDEXPR:
+                    //propagate those deferred types to the
+                    //diagnostic formatter
+                    return dt;
+                default:
+                    return super.apply(dt);
+            }
+        }
+
+        class RecoveryInfo extends ResultInfo {
+
+            public RecoveryInfo() {
+                attr.super(Kinds.VAL, Type.recoveryType, new Check.NestedCheckContext(chk.basicHandler) {
+                    @Override
+                    public DeferredAttrContext deferredAttrContext() {
+                        return deferredAttrContext;
+                    }
+                    @Override
+                    public boolean compatible(Type found, Type req, Warner warn) {
+                        return true;
+                    }
+                    @Override
+                    public void report(DiagnosticPosition pos, JCDiagnostic details) {
+                        //do nothing
+                    }
+                });
+            }
+
+            @Override
+            protected Type check(DiagnosticPosition pos, Type found) {
+                return chk.checkNonVoid(pos, super.check(pos, found));
+            }
+        }
+    }
+
+    /**
+     * Retrieves the list of inference variables that need to be inferred before
+     * an AST node can be type-checked
+     */
+    @SuppressWarnings("fallthrough")
+    List<Type> stuckVars(JCExpression tree, ResultInfo resultInfo) {
+        switch (tree.getTag()) {
+            case LAMBDA:
+            case REFERENCE:
+                Assert.error("not supported yet");
+            default:
+                return List.nil();
+        }
+    }
+}