8282274: Compiler implementation for Pattern Matching for switch (Third Preview)

src/java.base/share/classes/java/lang/MatchException.java

@@ -30,16 +30,17 @@
 /**
  * Thrown to indicate an unexpected failure in pattern matching.
  *
- * MatchException may be thrown when an exhaustive pattern matching language construct
- * (such as a switch expression) encounters a match target that does not match any of the provided
- * patterns at runtime.  This can currently arise from the following case:
- * <ul>
- *     <li>Separate compilation anomalies, where a sealed interface has a different
- *         set of permitted subtypes at runtime than it had at compilation time,
- *         an enum has a different set of constants at runtime than it had at compilation time,
- *         or the type hierarchy has changed in incompatible ways between compile time and run time.
- *     </li>
- * </ul>
+ * {@code MatchException} may be thrown when an exhaustive pattern matching language construct
+ * (such as a switch expression) encounters a value that does not match any of the provided
+ * patterns at runtime. This can currently arise for separate compilation anomalies,
+ * where a sealed interface has a different set of permitted subtypes at runtime than
+ * it had at compilation time, an enum has a different set of constants at runtime than
+ * it had at compilation time, or the type hierarchy has changed in incompatible ways between
+ * compile time and run time.
+ *
+ * @jls 14.11.3 Execution of a switch Statement
+ * @jls 14.30.2 Pattern Matching
+ * @jls 15.28.2 Run-Time Evaluation of switch Expressions
  *
  * @since   19
  */
@@ -49,7 +50,7 @@ public class MatchException extends RuntimeException {
     private static final long serialVersionUID = 0L;
 
     /**
-     * Constructs an {@code MatchException} with no detail  message.
+     * Constructs an {@code MatchException} with no detail message.
      */
     public MatchException() {
         super();
@@ -70,7 +71,7 @@ public MatchException(String message) {
      * Constructs an {@code MatchException} with the specified cause.
      *
      * @param  cause the cause (which is saved for later retrieval by the
-     *         {@link #getCause()} method).  (A {@code null} value is
+     *         {@link #getCause()} method). (A {@code null} value is
      *         permitted, and indicates that the cause is nonexistent or
      *         unknown.)
      */
@@ -85,7 +86,7 @@ public MatchException(Throwable cause) {
      * @param  message the detail message (which is saved for later retrieval
      *         by the {@link #getMessage()} method).
      * @param  cause the cause (which is saved for later retrieval by the
-     *         {@link #getCause()} method).  (A {@code null} value is
+     *         {@link #getCause()} method). (A {@code null} value is
      *         permitted, and indicates that the cause is nonexistent or
      *         unknown.)
      */

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Preview.java

@@ -187,7 +187,7 @@ public boolean isPreview(Feature feature) {
         return switch (feature) {
             case CASE_NULL -> true;
             case PATTERN_SWITCH -> true;
-            case TOTAL_PATTERN_IN_INSTACEOF -> true;
+            case UNCONDITIONAL_PATTERN_IN_INSTANCEOF -> true;
 
             //Note: this is a backdoor which allows to optionally treat all features as 'preview' (for testing).
             //When real preview features will be added, this method can be implemented to return 'true'

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

@@ -239,7 +239,7 @@ public enum Feature {
         CASE_NULL(JDK17, Fragments.FeatureCaseNull, DiagKind.NORMAL),
         PATTERN_SWITCH(JDK17, Fragments.FeaturePatternSwitch, DiagKind.PLURAL),
         REDUNDANT_STRICTFP(JDK17),
-        TOTAL_PATTERN_IN_INSTACEOF(JDK17, Fragments.FeatureTotalPatternsInInstanceof, DiagKind.PLURAL),
+        UNCONDITIONAL_PATTERN_IN_INSTANCEOF(JDK17, Fragments.FeatureTotalPatternsInInstanceof, DiagKind.PLURAL),
         ;
 
         enum DiagKind {

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

@@ -174,8 +174,8 @@ protected Attr(Context context) {
         allowRecords = Feature.RECORDS.allowedInSource(source);
         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
                              Feature.PATTERN_SWITCH.allowedInSource(source);
-        allowTotalPatternsInstance = (preview.isEnabled() || !preview.isPreview(Feature.TOTAL_PATTERN_IN_INSTACEOF)) &&
-                                     Feature.TOTAL_PATTERN_IN_INSTACEOF.allowedInSource(source);
+        allowUnconditionalPatternsInstance = (preview.isEnabled() || !preview.isPreview(Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF)) &&
+                                     Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
         sourceName = source.name;
         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 
@@ -222,7 +222,7 @@ protected Attr(Context context) {
 
     /** Are total patterns in instanceof allowed
      */
-    private final boolean allowTotalPatternsInstance;
+    private final boolean allowUnconditionalPatternsInstance;
 
     /**
      * Switch: warn about use of variable before declaration?
@@ -1794,7 +1794,7 @@ private void handleSwitch(JCTree switchTree,
                             }
                             matchBindings = matchBindingsComputer.caseGuard(c, afterPattern, matchBindings);
                         }
-                        boolean unconditional = TreeInfo.unconditionalCaseLabel(pat);
+                        boolean unconditional = TreeInfo.unrefinedCaseLabel(pat);
                         boolean isTotal = unconditional &&
                                           !patternType.isErroneous() &&
                                           types.isSubtype(types.erasure(seltype), patternType);
@@ -4109,10 +4109,10 @@ public void visitTypeTest(JCInstanceOf tree) {
             clazztype = tree.pattern.type;
             if (types.isSubtype(exprtype, clazztype) &&
                 !exprtype.isErroneous() && !clazztype.isErroneous()) {
-                if (!allowTotalPatternsInstance) {
+                if (!allowUnconditionalPatternsInstance) {
                     log.error(tree.pos(), Errors.InstanceofPatternNoSubtype(exprtype, clazztype));
-                } else if (preview.isPreview(Feature.TOTAL_PATTERN_IN_INSTACEOF)) {
-                    preview.warnPreview(tree.pattern.pos(), Feature.TOTAL_PATTERN_IN_INSTACEOF);
+                } else if (preview.isPreview(Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF)) {
+                    preview.warnPreview(tree.pattern.pos(), Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF);
                 }
             }
             typeTree = TreeInfo.primaryPatternTree((JCPattern) tree.pattern).var.vartype;

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

@@ -671,7 +671,7 @@ public void visitSwitch(JCSwitch tree) {
                 JCCase c = l.head;
                 for (JCCaseLabel pat : c.labels) {
                     scan(pat);
-                    if (TreeInfo.unconditionalCaseLabel(pat)) {
+                    if (TreeInfo.unrefinedCaseLabel(pat)) {
                         handleConstantCaseLabel(constants, pat);
                     }
                 }
@@ -714,7 +714,7 @@ public void visitSwitchExpression(JCSwitchExpression tree) {
                 JCCase c = l.head;
                 for (JCCaseLabel pat : c.labels) {
                     scan(pat);
-                    if (TreeInfo.unconditionalCaseLabel(pat)) {
+                    if (TreeInfo.unrefinedCaseLabel(pat)) {
                         handleConstantCaseLabel(constants, pat);
                     }
                 }

src/jdk.compiler/share/classes/com/sun/tools/javac/tree/TreeInfo.java

@@ -1346,7 +1346,7 @@ public static boolean isErrorEnumSwitch(JCExpression selector, List<JCCase> case
 
     public static PatternPrimaryType primaryPatternType(JCTree pat) {
         return switch (pat.getTag()) {
-            case BINDINGPATTERN -> new PatternPrimaryType(((JCBindingPattern) pat).type);
+            case BINDINGPATTERN -> new PatternPrimaryType(pat.type);
             case PARENTHESIZEDPATTERN -> primaryPatternType(((JCParenthesizedPattern) pat).pattern);
             default -> throw new AssertionError();
         };
@@ -1369,7 +1369,7 @@ public static boolean expectedExhaustive(JCSwitch tree) {
                          .anyMatch(l -> TreeInfo.isNull(l));
     }
 
-    public static boolean unconditionalCaseLabel(JCCaseLabel cse) {
+    public static boolean unrefinedCaseLabel(JCCaseLabel cse) {
         if (!cse.isPattern()) {
             return true;
         }