8332463: Byte conditional pattern case element dominates short constant case element

Reviewed-by: vromero

Author: biboudis

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

@@ -4818,7 +4818,6 @@ void checkSwitchCaseLabelDominated(JCCaseLabel unconditionalCaseLabel, List<JCCa
                     JCCaseLabel testCaseLabel = caseAndLabel.snd;
                     Type testType = labelType(testCaseLabel);
                     boolean dominated = false;
-                    if (unconditionalCaseLabel == testCaseLabel) unconditionalFound = true;
                     if (types.isUnconditionallyExact(currentType, testType) &&
                         !currentType.hasTag(ERROR) && !testType.hasTag(ERROR)) {
                         //the current label is potentially dominated by the existing (test) label, check:
@@ -4833,11 +4832,6 @@ void checkSwitchCaseLabelDominated(JCCaseLabel unconditionalCaseLabel, List<JCCa
                         }
                     }
 
-                    // Domination can occur even when we have not an unconditional pair between case labels.
-                    if (unconditionalFound && unconditionalCaseLabel != label) {
-                        dominated = true;
-                    }
-
                     if (dominated) {
                         log.error(label.pos(), Errors.PatternDominated);
                     }

test/langtools/tools/javac/patterns/PrimitivePatternsSwitchErrors.java

@@ -1,6 +1,6 @@
 /*
  * @test /nodynamiccopyright/
- * @bug 8304487 8325653
+ * @bug 8304487 8325653 8332463
  * @summary Compiler Implementation for Primitive types in patterns, instanceof, and switch (Preview)
  * @enablePreview
  * @compile/fail/ref=PrimitivePatternsSwitchErrors.out -XDrawDiagnostics -XDshould-stop.at=FLOW PrimitivePatternsSwitchErrors.java
@@ -59,7 +59,7 @@ public static int dominationBetweenBoxedAndPrimitive() {
         int i = 42;
         return switch (i) {
             case Integer ib  -> ib;
-            case byte ip     -> ip; // Error - dominated!
+            case byte ip     -> ip; // OK - not dominated!
         };
     }
 

test/langtools/tools/javac/patterns/PrimitivePatternsSwitchErrors.out

@@ -1,7 +1,6 @@
 PrimitivePatternsSwitchErrors.java:15:18: compiler.err.pattern.dominated
 PrimitivePatternsSwitchErrors.java:24:18: compiler.err.pattern.dominated
 PrimitivePatternsSwitchErrors.java:31:24: compiler.err.prob.found.req: (compiler.misc.inconvertible.types: int, java.lang.Long)
-PrimitivePatternsSwitchErrors.java:62:18: compiler.err.pattern.dominated
 PrimitivePatternsSwitchErrors.java:70:18: compiler.err.pattern.dominated
 PrimitivePatternsSwitchErrors.java:78:18: compiler.err.pattern.dominated
 PrimitivePatternsSwitchErrors.java:84:18: compiler.err.prob.found.req: (compiler.misc.possible.loss.of.precision: long, byte)
@@ -44,4 +43,4 @@ PrimitivePatternsSwitchErrors.java:254:16: compiler.err.not.exhaustive
 PrimitivePatternsSwitchErrors.java:260:16: compiler.err.not.exhaustive
 - compiler.note.preview.filename: PrimitivePatternsSwitchErrors.java, DEFAULT
 - compiler.note.preview.recompile
-44 errors
+43 errors

test/langtools/tools/javac/patterns/T8332463a.java

@@ -0,0 +1,54 @@
+/*
+ * 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 8332463
+ * @summary Byte conditional pattern case element dominates short constant case element
+ * @compile --enable-preview --source ${jdk.version} T8332463a.java
+ */
+public class T8332463a {
+    public int test2() {
+        Byte i = (byte) 42;
+        return switch (i) {
+            case Byte ib  -> 1;
+            case short s  -> 2;
+        };
+    }
+
+    public int test4() {
+        int i = 42;
+        return switch (i) {
+            case Integer ib -> 1;
+            case byte ip    -> 2;
+        };
+    }
+
+    public int test3() {
+        int i = 42;
+        return switch (i) {
+            case Integer ib -> 1;
+            case (byte) 0   -> 2;
+        };
+    }
+}

test/langtools/tools/javac/patterns/T8332463b.java

@@ -0,0 +1,40 @@
+/*
+ * 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 8332463
+ * @summary Byte conditional pattern case element dominates short constant case element
+ * @enablePreview
+ * @compile T8332463b.java
+ *  @compile --enable-preview --source ${jdk.version} T8332463b.java
+ */
+public class T8332463b {
+    public int test1() {
+        Byte i = (byte) 42;
+        return switch (i) {
+            case Byte ib   -> 1;
+            case (short) 0 -> 2;
+        };
+    }
+}