8328747: WrongMethodTypeException with pattern matching on switch on sealed classes

Reviewed-by: cushon, vromero

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

@@ -106,7 +106,6 @@ import com.sun.tools.javac.tree.JCTree.LetExpr;
 import com.sun.tools.javac.tree.TreeInfo;
 import com.sun.tools.javac.tree.TreeScanner;
 import com.sun.tools.javac.util.Assert;
-import com.sun.tools.javac.util.JCDiagnostic;
 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
 import com.sun.tools.javac.util.List;
 
@@ -393,7 +392,7 @@ public class TransPatterns extends TreeTranslator {
                               boolean hasUnconditionalPattern,
                               boolean patternSwitch) {
         if (patternSwitch) {
-            Type seltype = selector.type.hasTag(BOT)
+            Type seltype = selector.type.hasTag(BOT) || target.usesReferenceOnlySelectorTypes()
                     ? syms.objectType
                     : selector.type;
 
@@ -496,14 +495,12 @@ public class TransPatterns extends TreeTranslator {
                          .toArray(s -> new LoadableConstant[s]);
 
             boolean enumSelector = seltype.tsym.isEnum();
-            boolean primitiveSelector = seltype.isPrimitive();
             Name bootstrapName = enumSelector ? names.enumSwitch : names.typeSwitch;
             MethodSymbol bsm = rs.resolveInternalMethod(tree.pos(), env, syms.switchBootstrapsType,
                     bootstrapName, staticArgTypes, List.nil());
 
-            Type resolvedSelectorType = seltype;
             MethodType indyType = new MethodType(
-                    List.of(resolvedSelectorType, syms.intType),
+                    List.of(seltype, syms.intType),
                     syms.intType,
                     List.nil(),
                     syms.methodClass

src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Target.java

@@ -226,4 +226,10 @@ public enum Target {
     public boolean optimizeOuterThis() {
         return compareTo(JDK1_18) >= 0;
     }
+
+    /** Releases prior to JDK 23 expect a less precise SwitchBootstraps.typeSwitch signature on the selectorType
+     */
+    public boolean usesReferenceOnlySelectorTypes() {
+        return compareTo(Target.JDK1_23) < 0;
+    }
 }

test/langtools/tools/javac/T8328747.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2024, 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 8328747
+ * @summary WrongMethodTypeException with pattern matching on switch on sealed classes
+ * @library /tools/lib
+ * @modules jdk.compiler/com.sun.tools.javac.api
+ *          jdk.compiler/com.sun.tools.javac.main
+ *          jdk.jdeps/com.sun.tools.javap
+ * @build toolbox.ToolBox toolbox.JavapTask
+ * @compile T8328747.java
+ * @run main T8328747
+ */
+
+import toolbox.*;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+public class T8328747 extends TestRunner  {
+    private ToolBox tb;
+
+    public static void main(String... args) throws Exception {
+        new T8328747().runTests();
+    }
+
+    T8328747() {
+        super(System.err);
+        tb = new ToolBox();
+    }
+
+    public void runTests() throws Exception {
+        runTests(m -> new Object[] { Paths.get(m.getName()) });
+    }
+
+    @Test
+    public void test(Path base) throws Exception {
+        Path current = base.resolve(".");
+        Path src = current.resolve("src");
+        Path classes = current.resolve("classes");
+        tb.writeJavaFiles(src,
+                """
+                package test;
+                public class Test {
+                   public static void main(String[] args) {
+                     f(new P());
+                     f(new O());
+                   }
+
+                   private static void f(I info) {
+                     switch (info) {
+                       case P p -> System.err.println(p);
+                       case O o -> System.err.println(o);
+                     }
+                   }
+
+                   static sealed interface I permits P, O {}
+                   private abstract static class A {}
+                   static final class P extends A implements I {}
+                   static final class O extends A implements I {}
+                }
+                """);
+
+        Files.createDirectories(classes);
+
+        {//with --release:
+            new JavacTask(tb)
+                    .options("--release", "21")
+                    .outdir(classes)
+                    .files(tb.findJavaFiles(src))
+                    .run(Task.Expect.SUCCESS)
+                    .writeAll();
+
+            String javapOut = new JavapTask(tb)
+                    .options("-v")
+                    .classpath(classes.toString())
+                    .classes("test.Test")
+                    .run()
+                    .getOutput(Task.OutputKind.DIRECT);
+
+            if (!javapOut.contains("#25 = InvokeDynamic      #0:#26         // #0:typeSwitch:(Ljava/lang/Object;I)I"))
+                throw new AssertionError("typeSwitch for a version less than 23 should accept a static type of java.lang.Object");
+        }
+
+        {//without:
+            new JavacTask(tb)
+                    .outdir(classes)
+                    .files(tb.findJavaFiles(src))
+                    .run(Task.Expect.SUCCESS)
+                    .writeAll();
+
+            String javapOut = new JavapTask(tb)
+                    .options("-v")
+                    .classpath(classes.toString())
+                    .classes("test.Test")
+                    .run()
+                    .getOutput(Task.OutputKind.DIRECT);
+
+            if (!javapOut.contains("#25 = InvokeDynamic      #0:#26         // #0:typeSwitch:(Ltest/Test$I;I)I"))
+                throw new AssertionError("typeSwitch from version 23 and beyond should accept a precise selector type");
+        }
+    }
+}