Bug 574564 - [17] switch label error - pattern rules [Any Pattern part]Y20210720-0800

Change-Id: I8d3cff818a97e328336f0d7ddd324dd1ddd33552
Signed-off-by: Manoj Palat <manpalat@in.ibm.com>
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.core/+/183161
Tested-by: JDT Bot <jdt-bot@eclipse.org>

6 files changed, 268 insertions, 28 deletions

diff --git a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/CompilerInvocationTests.java b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/CompilerInvocationTests.java
index f6c508b0b7..262b9b3c4c 100644
--- a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/CompilerInvocationTests.java
+++ b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/CompilerInvocationTests.java
@@ -1301,6 +1301,7 @@ public void test011_problem_categories() {
 	    expectedProblemAttributes.put("SwitchPatternConstantCaseLabelIncompatible", new ProblemAttributes(true));
 	    expectedProblemAttributes.put("SwitchPatternConstantWithPatternIncompatible", new ProblemAttributes(true));
 	    expectedProblemAttributes.put("IllegalFallthroughToPattern", new ProblemAttributes(true));
+	    expectedProblemAttributes.put("SwitchPatternAnyPatternCaseLabelNotAllowed", new ProblemAttributes(true));
 
 	    StringBuffer failures = new StringBuffer();
 		StringBuffer correctResult = new StringBuffer(70000);
@@ -2372,6 +2373,7 @@ public void test012_compiler_problems_tuning() {
 	    expectedProblemAttributes.put("SwitchPatternConstantCaseLabelIncompatible", SKIP);
 	    expectedProblemAttributes.put("SwitchPatternConstantWithPatternIncompatible", SKIP);
 	    expectedProblemAttributes.put("IllegalFallthroughToPattern", SKIP);
+	    expectedProblemAttributes.put("SwitchPatternAnyPatternCaseLabelNotAllowed", SKIP);
 	    Map constantNamesIndex = new HashMap();
 		Field[] fields = JavaCore.class.getFields();
 		for (int i = 0, length = fields.length; i < length; i++) {
diff --git a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SwitchPatternTest.java b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SwitchPatternTest.java
index 641953de86..f630fae6a2 100644
--- a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SwitchPatternTest.java
+++ b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SwitchPatternTest.java
@@ -27,7 +27,7 @@ public class SwitchPatternTest extends AbstractRegressionTest9 {
 	static {
 //		TESTS_NUMBERS = new int [] { 40 };
 //		TESTS_RANGE = new int[] { 1, -1 };
-//		TESTS_NAMES = new String[] { "testBug574793_001"};
+//		TESTS_NAMES = new String[] { "testBug574564_00de6"};
 	}
 
 	private static String previewLevel = "17";
@@ -1750,4 +1750,223 @@ public class SwitchPatternTest extends AbstractRegressionTest9 {
 				"A switch labeled block in a switch expression should not complete normally\n" +
 				"----------\n");
 	}
+	public void testBug574564_001() {
+		runNegativeTest(
+			new String[] {
+				"X.java",
+				"public class X {\n"+
+				" public static void main(String[] args) {\n"+
+				"   foo(new String(\"Hello\"));\n"+
+				" }\n"+
+				" private static void foo(Object o) {\n"+
+				"   switch (o) {\n"+
+				"     case var i  -> System.out.println(0);\n"+
+				"     default -> System.out.println(o);\n"+
+				"   }\n"+
+				" }\n"+
+				"}",
+			},
+			"----------\n" +
+			"1. ERROR in X.java (at line 7)\n" +
+			"	case var i  -> System.out.println(0);\n" +
+			"	     ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n");
+	}
+	public void testBug574564_002() {
+		runNegativeTest(
+			new String[] {
+				"X.java",
+				"public class X {\n"+
+				" public static void main(String[] args) {\n"+
+				"   foo(new String(\"Hello\"));\n"+
+				" }\n"+
+				" private static void foo(Object o) {\n"+
+				"   switch (o) {\n"+
+				"     case var i, var j, var k  -> System.out.println(0);\n"+
+				"     default -> System.out.println(o);\n"+
+				"   }\n"+
+				" }\n"+
+				"}",
+			},
+			"----------\n" +
+			"1. ERROR in X.java (at line 7)\n" +
+			"	case var i, var j, var k  -> System.out.println(0);\n" +
+			"	     ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n" +
+			"2. ERROR in X.java (at line 7)\n" +
+			"	case var i, var j, var k  -> System.out.println(0);\n" +
+			"	            ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n" +
+			"3. ERROR in X.java (at line 7)\n" +
+			"	case var i, var j, var k  -> System.out.println(0);\n" +
+			"	                   ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n");
+	}
+	public void testBug574564_003() {
+		runNegativeTest(
+			new String[] {
+				"X.java",
+				"public class X {\n"+
+				" public static void main(String[] args) {\n"+
+				"   foo(10);\n"+
+				" }\n"+
+				" private static void foo(Integer o) {\n"+
+				"   switch (o) {\n"+
+				"     case var i, 10  -> System.out.println(0);\n"+
+				"     default -> System.out.println(o);\n"+
+				"   }\n"+
+				" }\n"+
+				"}",
+			},
+			"----------\n" +
+			"1. ERROR in X.java (at line 7)\n" +
+			"	case var i, 10  -> System.out.println(0);\n" +
+			"	     ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n");
+	}
+	public void testBug574564_004() {
+		runNegativeTest(
+			new String[] {
+				"X.java",
+				"public class X {\n"+
+				" public static void main(String[] args) {\n"+
+				"   foo(10);\n"+
+				" }\n"+
+				" private static void foo(Integer o) {\n"+
+				"   switch (o) {\n"+
+				"     case var i, 10, var k  -> System.out.println(0);\n"+
+				"     default -> System.out.println(o);\n"+
+				"   }\n"+
+				" }\n"+
+				"}",
+			},
+			"----------\n" +
+			"1. ERROR in X.java (at line 7)\n" +
+			"	case var i, 10, var k  -> System.out.println(0);\n" +
+			"	     ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n" +
+			"2. ERROR in X.java (at line 7)\n" +
+			"	case var i, 10, var k  -> System.out.println(0);\n" +
+			"	                ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n");
+	}
+	public void testBug574564_005() {
+		runNegativeTest(
+			new String[] {
+				"X.java",
+				"public class X {\n"+
+				" public static void main(String[] args) {\n"+
+				"   foo(10);\n"+
+				" }\n"+
+				" private static void foo(Integer o) {\n"+
+				"   switch (o) {\n"+
+				"     case  10, null, var k  -> System.out.println(0);\n"+
+				"     default -> System.out.println(o);\n"+
+				"   }\n"+
+				" }\n"+
+				"}",
+			},
+			"----------\n" +
+			"1. ERROR in X.java (at line 7)\n" +
+			"	case  10, null, var k  -> System.out.println(0);\n" +
+			"	                ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n");
+	}
+	public void testBug574564_006() {
+		runNegativeTest(
+			new String[] {
+				"X.java",
+				"public class X {\n"+
+				" public static void main(String[] args) {\n"+
+				"   foo(10);\n"+
+				" }\n"+
+				" private static void foo(Integer o) {\n"+
+				"   switch (o) {\n"+
+				"     case  default, var k  -> System.out.println(0);\n"+
+				"     default -> System.out.println(o);\n"+
+				"   }\n"+
+				" }\n"+
+				"}",
+			},
+			"----------\n" +
+			"1. ERROR in X.java (at line 7)\n" +
+			"	case  default, var k  -> System.out.println(0);\n" +
+			"	               ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n" +
+			"2. ERROR in X.java (at line 8)\n" +
+			"	default -> System.out.println(o);\n" +
+			"	^^^^^^^\n" +
+			"The default case is already defined\n" +
+			"----------\n");
+	}
+	public void testBug574564_007() {
+		runNegativeTest(
+			new String[] {
+				"X.java",
+				"public class X {\n"+
+				" public static void main(String[] args) {\n"+
+				"   foo(10);\n"+
+				" }\n"+
+				" private static void foo(Integer o) {\n"+
+				"   switch (o) {\n"+
+				"     case  default, default, var k  -> System.out.println(0);\n"+
+				"     default -> System.out.println(o);\n"+
+				"   }\n"+
+				" }\n"+
+				"}",
+			},
+			"----------\n" +
+			"1. ERROR in X.java (at line 7)\n" +
+			"	case  default, default, var k  -> System.out.println(0);\n" +
+			"	                     ^^^^^^^^\n" +
+			"The default case is already defined\n" +
+			"----------\n" +
+			"2. ERROR in X.java (at line 7)\n" +
+			"	case  default, default, var k  -> System.out.println(0);\n" +
+			"	                        ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n" +
+			"3. ERROR in X.java (at line 8)\n" +
+			"	default -> System.out.println(o);\n" +
+			"	^^^^^^^\n" +
+			"The default case is already defined\n" +
+			"----------\n");
+	}
+	public void testBug574564_008() {
+		runNegativeTest(
+			new String[] {
+				"X.java",
+				"public class X {\n"+
+				" public static void main(String[] args) {\n"+
+				"   foo(10);\n"+
+				" }\n"+
+				" private static void foo(Integer o) {\n"+
+				"   switch (o) {\n"+
+				"     case  default, 1, var k  -> System.out.println(0);\n"+
+				"     default -> System.out.println(o);\n"+
+				"   }\n"+
+				" }\n"+
+				"}",
+			},
+			"----------\n" +
+			"1. ERROR in X.java (at line 7)\n" +
+			"	case  default, 1, var k  -> System.out.println(0);\n" +
+			"	                  ^^^^^\n" +
+			"Any patterns not allowed as switch case label elements\n" +
+			"----------\n" +
+			"2. ERROR in X.java (at line 8)\n" +
+			"	default -> System.out.println(o);\n" +
+			"	^^^^^^^\n" +
+			"The default case is already defined\n" +
+			"----------\n");
+	}
 }
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/core/compiler/IProblem.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/core/compiler/IProblem.java
index 652bc57ce3..ed5c682eaf 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/core/compiler/IProblem.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/core/compiler/IProblem.java
@@ -2486,4 +2486,7 @@ void setSourceStart(int sourceStart);
 	 */
 	int IllegalFallthroughToPattern = PreviewRelated + 1904;
 
+	/** @since 3.27 BETA_JAVA17
+	 * @noreference preview feature error */
+	int SwitchPatternAnyPatternCaseLabelNotAllowed = PreviewRelated + 1905;
 }
\ No newline at end of file
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/CaseStatement.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/CaseStatement.java
index 844a5fad97..e2d03f8b31 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/CaseStatement.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/CaseStatement.java
@@ -197,38 +197,40 @@ public Constant[] resolveWithPatternVariablesInScope(LocalVariableBinding[] patt
 		return resolveCasePrivate(scope, switchExpressionType, switchStatement);
 	}
 }
-private Expression getFirstNonDefaultExpression() {
-	if (this.constantExpressions != null) {
-		for (Expression e : this.constantExpressions) {
-			if (!(e instanceof FakeDefaultLiteral)) return e;
+private Expression getFirstValidExpression(BlockScope scope, SwitchStatement switchStatement) {
+	assert this.constantExpressions != null;
+	Expression ret = null;
+
+	for (Expression e : this.constantExpressions) {
+		if (e instanceof PatternExpression && ((PatternExpression) e).pattern instanceof AnyPattern) {
+			// flag error
+			scope.problemReporter().switchPatternAnyPatternCaseLabelNotAllowed(e);
+		} else  if (e instanceof FakeDefaultLiteral) {
+			flagDuplicateDefault(scope, switchStatement);
+		} else {
+			ret = ret != null ? ret : e;
 		}
 	}
-	return null;
+	return ret;
 }
 private Constant[] resolveCasePrivate(BlockScope scope, TypeBinding switchExpressionType, SwitchStatement switchStatement) {
 	// switchExpressionType maybe null in error case
 	scope.enclosingCase = this; // record entering in a switch case block
-	Expression constExpr = getFirstNonDefaultExpression();
-	int defaultCount = 0;
-	int nConstExprs = this.constantExpressions != null ? this.constantExpressions.length : 0;
+	if (this.constantExpressions == null) {
+		flagDuplicateDefault(scope, switchStatement);
+		return Constant.NotAConstantList;
+	}
+	Expression constExpr = getFirstValidExpression(scope, switchStatement);
 	if (constExpr == null) {
-		do {
-			++defaultCount;
-			// remember the default case into the associated switch statement
-			if (switchStatement.defaultCase != null)
-				scope.problemReporter().duplicateDefaultCase(this);
-
-			// on error the last default will be the selected one ...
-			switchStatement.defaultCase = this;
-		} while (defaultCount < nConstExprs);
 		return Constant.NotAConstantList;
 	}
+
 	// add into the collection of cases of the associated switch statement
 	switchStatement.cases[switchStatement.caseCount++] = this;
 	if (switchExpressionType != null && switchExpressionType.isEnum() && (constExpr instanceof SingleNameReference)) {
 		((SingleNameReference) constExpr).setActualReceiverType((ReferenceBinding)switchExpressionType);
 	}
-//	this.scope = new BlockScope(scope);
+
 	TypeBinding caseType = constExpr.resolveType(scope);
 	if (caseType == null || switchExpressionType == null) return Constant.NotAConstantList;
 	// tag constant name with enum type for privileged access to its members
@@ -238,15 +240,9 @@ private Constant[] resolveCasePrivate(BlockScope scope, TypeBinding switchExpres
 		if (e != constExpr) {
 			if (switchExpressionType.isEnum() && (e instanceof SingleNameReference)) {
 				((SingleNameReference) e).setActualReceiverType((ReferenceBinding)switchExpressionType);
-			} else if (e instanceof FakeDefaultLiteral) {
-				if (switchStatement.defaultCase != null)
-					scope.problemReporter().duplicateDefaultCase(this);
-
-				// on error the last default will be the selected one ...
-				switchStatement.defaultCase = this;
-				continue;
-				// TODO: flag a preview error conditionally based on level?
-				// Predicate<BlockScope> patternSwitchAllowed = (skope) -> JavaFeature.PATTERN_MATCHING_IN_SWITCH.isSupported(skope.compilerOptions());
+			} else if (e instanceof FakeDefaultLiteral
+					|| e instanceof PatternExpression && ((PatternExpression) e).pattern instanceof AnyPattern) {
+				continue; // already processed
 			}
 			e.resolveType(scope);
 		}
@@ -262,6 +258,15 @@ private Constant[] resolveCasePrivate(BlockScope scope, TypeBinding switchExpres
 
 	return Constant.NotAConstantList;
 }
+
+private void flagDuplicateDefault(BlockScope scope, SwitchStatement switchStatement) {
+	// remember the default case into the associated switch statement
+	if (switchStatement.defaultCase != null)
+		scope.problemReporter().duplicateDefaultCase(this);
+
+	// on error the last default will be the selected one ...
+	switchStatement.defaultCase = this;
+}
 public void collectPatternVariablesToScope(LocalVariableBinding[] variables, BlockScope scope) {
 	if (!containsPatternVariable()) {
 		return;
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java
index 56102b61c9..c42adfbc4e 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java
@@ -12241,4 +12241,14 @@ public void IllegalFallThroughToPattern(CaseStatement caseStatement) {
 		caseStatement.sourceStart,
 		caseStatement.sourceEnd);
 	}
+public void switchPatternAnyPatternCaseLabelNotAllowed(Expression element) {
+	if (!this.options.enablePreviewFeatures)
+		return;
+	this.handle(
+			IProblem.SwitchPatternAnyPatternCaseLabelNotAllowed,
+			NoArgument,
+			NoArgument,
+			element.sourceStart,
+			element.sourceEnd);
+}
 }
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/messages.properties b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/messages.properties
index b30cae879f..96192a3832 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/messages.properties
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/messages.properties
@@ -1121,6 +1121,7 @@
 1902 = The constant case label element is not compatible with switch expression type {0}
 1903 = Constant case label elements and pattern case label elements cannot be present in a switch label
 1904 = Illegal fall-through to a pattern case label 
+1905 = Any patterns not allowed as switch case label elements
 
 ### ELABORATIONS
 ## Access restrictions