8268312: Compilation error with nested generic functional interface

Reviewed-by: mcimadamore

Author: Vicente Romero

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Resolve.java

@@ -68,6 +68,7 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
+import java.util.function.UnaryOperator;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 
@@ -4174,16 +4175,11 @@ JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
                 return null;
 
             Pair<Symbol, JCDiagnostic> c = errCandidate();
-            if (compactMethodDiags) {
-                JCDiagnostic simpleDiag =
-                    MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, c.snd);
-                if (simpleDiag != null) {
-                    return simpleDiag;
-                }
-            }
             Symbol ws = c.fst.asMemberOf(site, types);
             return diags.create(dkind, log.currentSource(), pos,
                       "cant.apply.symbol",
+                      compactMethodDiags ?
+                              d -> MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, c.snd) : null,
                       kindName(ws),
                       ws.name == names.init ? ws.owner.name : ws.name,
                       methodArguments(ws.type.getParameterTypes()),
@@ -4244,8 +4240,8 @@ JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
                 JCDiagnostic err = diags.create(dkind,
                         null,
                         truncatedDiag ?
-                            EnumSet.of(DiagnosticFlag.COMPRESSED) :
-                            EnumSet.noneOf(DiagnosticFlag.class),
+                                EnumSet.of(DiagnosticFlag.COMPRESSED) :
+                                EnumSet.noneOf(DiagnosticFlag.class),
                         log.currentSource(),
                         pos,
                         "cant.apply.symbols",

src/jdk.compiler/share/classes/com/sun/tools/javac/util/AbstractDiagnosticFormatter.java

@@ -182,7 +182,11 @@ protected String formatArgument(JCDiagnostic d, Object arg, Locale l) {
             String s = null;
             depth++;
             try {
-                s = formatMessage(diagnostic, l);
+                JCDiagnostic rewrittenDiagnostic = null;
+                if (diagnostic.hasRewriter()) {
+                    rewrittenDiagnostic = diagnostic.rewrite();
+                }
+                s = formatMessage(rewrittenDiagnostic != null ? rewrittenDiagnostic : diagnostic, l);
             }
             finally {
                 depth--;

src/jdk.compiler/share/classes/com/sun/tools/javac/util/JCDiagnostic.java

@@ -26,6 +26,7 @@
 package com.sun.tools.javac.util;
 
 import java.util.EnumSet;
+import java.util.function.UnaryOperator;
 import java.util.Locale;
 import java.util.Set;
 import java.util.stream.Stream;
@@ -243,6 +244,21 @@ public JCDiagnostic create(
             return create(null, EnumSet.noneOf(DiagnosticFlag.class), source, pos, DiagnosticInfo.of(kind, prefix, key, args));
         }
 
+        /**
+         * Create a new diagnostic of the given kind, which is not mandatory and which has
+         * no lint category.
+         *  @param kind        The diagnostic kind
+         *  @param source      The source of the compilation unit, if any, in which to report the message.
+         *  @param pos         The source position at which to report the message.
+         *  @param key         The key for the localized message.
+         *  @param rewriter    A rewriter function used if this diagnostic needs to be rewritten
+         *  @param args        Fields of the message.
+         */
+        public JCDiagnostic create(
+                DiagnosticType kind, DiagnosticSource source, DiagnosticPosition pos, String key, UnaryOperator<JCDiagnostic> rewriter, Object... args) {
+            return create(null, EnumSet.noneOf(DiagnosticFlag.class), source, pos, DiagnosticInfo.of(kind, prefix, key, args), rewriter);
+        }
+
         /**
          * Create a new diagnostic of the given kind, which is not mandatory and which has
          * no lint category.
@@ -282,6 +298,11 @@ public JCDiagnostic create(
                 LintCategory lc, Set<DiagnosticFlag> flags, DiagnosticSource source, DiagnosticPosition pos, DiagnosticInfo diagnosticInfo) {
             return new JCDiagnostic(formatter, normalize(diagnosticInfo), lc, flags, source, pos);
         }
+
+        public JCDiagnostic create(
+                LintCategory lc, Set<DiagnosticFlag> flags, DiagnosticSource source, DiagnosticPosition pos, DiagnosticInfo diagnosticInfo, UnaryOperator<JCDiagnostic> rewriter) {
+            return new JCDiagnostic(formatter, normalize(diagnosticInfo), lc, flags, source, pos, rewriter);
+        }
         //where
             DiagnosticInfo normalize(DiagnosticInfo diagnosticInfo) {
                 //replace all nested FragmentKey with full-blown JCDiagnostic objects
@@ -446,6 +467,8 @@ public enum DiagnosticFlag {
     /** source line position (set lazily) */
     private SourcePosition sourcePosition;
 
+    private final UnaryOperator<JCDiagnostic> rewriter;
+
     /**
      * This class is used to defer the line/column position fetch logic after diagnostic construction.
      */
@@ -596,6 +619,25 @@ protected JCDiagnostic(DiagnosticFormatter<JCDiagnostic> formatter,
                        Set<DiagnosticFlag> flags,
                        DiagnosticSource source,
                        DiagnosticPosition pos) {
+        this(formatter, diagnosticInfo, lc, flags, source, pos, null);
+    }
+
+    /**
+     * Create a diagnostic object.
+     * @param formatter the formatter to use for the diagnostic
+     * @param diagnosticInfo the diagnostic key
+     * @param lc     the lint category for the diagnostic
+     * @param source the name of the source file, or null if none.
+     * @param pos the character offset within the source file, if given.
+     * @param rewriter the rewriter function used if this diagnostic needs to be rewritten
+     */
+    protected JCDiagnostic(DiagnosticFormatter<JCDiagnostic> formatter,
+                           DiagnosticInfo diagnosticInfo,
+                           LintCategory lc,
+                           Set<DiagnosticFlag> flags,
+                           DiagnosticSource source,
+                           DiagnosticPosition pos,
+                           UnaryOperator<JCDiagnostic> rewriter) {
         if (source == null && pos != null && pos.getPreferredPosition() != Position.NOPOS)
             throw new IllegalArgumentException();
 
@@ -605,6 +647,7 @@ protected JCDiagnostic(DiagnosticFormatter<JCDiagnostic> formatter,
         this.flags = flags;
         this.source = source;
         this.position = pos;
+        this.rewriter = rewriter;
     }
 
     /**
@@ -807,6 +850,14 @@ public boolean isFlagSet(DiagnosticFlag flag) {
         return flags.contains(flag);
     }
 
+    boolean hasRewriter() {
+        return rewriter != null;
+    }
+
+    JCDiagnostic rewrite() {
+        return rewriter.apply(this);
+    }
+
     public static class MultilineDiagnostic extends JCDiagnostic {
 
         private final List<JCDiagnostic> subdiagnostics;

src/jdk.compiler/share/classes/com/sun/tools/javac/util/Log.java

@@ -28,7 +28,6 @@
 import java.io.*;
 import java.util.Arrays;
 import java.util.EnumMap;
-import java.util.EnumSet;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Queue;
@@ -671,6 +670,11 @@ public void report(JCDiagnostic diagnostic) {
             if (expectDiagKeys != null)
                 expectDiagKeys.remove(diagnostic.getCode());
 
+            if (diagnostic.hasRewriter()) {
+                JCDiagnostic rewrittenDiag = diagnostic.rewrite();
+                diagnostic = rewrittenDiag != null ? rewrittenDiag : diagnostic;
+            }
+
             switch (diagnostic.getType()) {
             case FRAGMENT:
                 throw new IllegalArgumentException();

test/langtools/tools/javac/diags/DiagnosticRewriterTest3.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2022, 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 8268312
+ * @summary Compilation error with nested generic functional interface
+ * @compile DiagnosticRewriterTest3.java
+ */
+
+import java.util.Optional;
+
+class DiagnosticRewriterTest3 {
+    void m() {
+        Optional.of("").map(outer -> {
+            Optional.of("")
+                    .map(inner -> returnGeneric(outer))
+                    .ifPresent(String::toString);
+            return "";
+        });
+    }
+
+    <T> T returnGeneric(T generic) {
+        return generic;
+    }
+}