[Sealed Types] Permits clause handling in scanner and parser is unnec…

…essarily complicated (#2653)

* Fixes #2652

org.eclipse.jdt.core.compiler.batch/grammar/java.g

@@ -45,7 +45,7 @@ $Terminals
 	abstract assert boolean break byte case catch char class
 	continue const default do double else enum extends false final finally float
 	for goto if implements import instanceof int
-	interface long native new non-sealed null package private
+	interface long native new non-sealed null package permits private
 	protected public return short static strictfp super switch
 	synchronized this throw throws transient true try void
 	volatile while module open requires transitive exports opens to uses provides with
@@ -120,7 +120,6 @@ $Terminals
 	RestrictedIdentifierYield
 	RestrictedIdentifierrecord
 	RestrictedIdentifiersealed
-	RestrictedIdentifierpermits
 	BeginCaseElement
 	RestrictedIdentifierWhen
 	UNDERSCORE
@@ -233,7 +232,6 @@ Goal ::= '->' YieldStatement
 Goal ::= '->' SwitchLabelCaseLhs
 -- JSR 360 Restricted
 Goal ::= RestrictedIdentifiersealed Modifiersopt
-Goal ::= RestrictedIdentifierpermits PermittedSubclasses
 -- jsr 427 --
 Goal ::= BeginCaseElement Pattern
 Goal ::= RestrictedIdentifierWhen Expression
@@ -702,7 +700,7 @@ ClassDeclaration ::= ClassHeader ClassBody
 /.$putCase consumeClassDeclaration(); $break ./
 /:$readableName ClassDeclaration:/
 
-ClassHeader ::= ClassHeaderName ClassHeaderExtendsopt ClassHeaderImplementsopt ClassHeaderPermittedSubclassesopt
+ClassHeader ::= ClassHeaderName ClassHeaderExtendsopt ClassHeaderImplementsopt PermittedTypesopt
 /.$putCase consumeClassHeader(); $break ./
 /:$readableName ClassHeader:/
 
@@ -1056,7 +1054,7 @@ InterfaceDeclaration ::= InterfaceHeader InterfaceBody
 /.$putCase consumeInterfaceDeclaration(); $break ./
 /:$readableName InterfaceDeclaration:/
 
-InterfaceHeader ::= InterfaceHeaderName InterfaceHeaderExtendsopt InterfaceHeaderPermittedSubClassesAndSubInterfacesopt
+InterfaceHeader ::= InterfaceHeaderName InterfaceHeaderExtendsopt PermittedTypesopt
 /.$putCase consumeInterfaceHeader(); $break ./
 /:$readableName InterfaceHeader:/
 
@@ -2412,29 +2410,11 @@ ClassHeaderImplementsopt ::= $empty
 ClassHeaderImplementsopt -> ClassHeaderImplements
 /:$readableName ClassHeaderImplements:/
 
-ClassHeaderPermittedSubclassesopt ::= $empty
-ClassHeaderPermittedSubclassesopt -> ClassHeaderPermittedSubclasses
-/:$readableName ClassHeaderPermittedSubclasses:/
-/:$compliance 15:/
-
--- Production name hardcoded in parser. Must be ::= and not ->
-PermittedSubclasses ::= ClassTypeList
-/:$readableName PermittedSubclasses:/
-
-ClassHeaderPermittedSubclasses ::= RestrictedIdentifierpermits ClassTypeList
-/.$putCase consumeClassHeaderPermittedSubclasses(); $break ./
-/:$readableName ClassHeaderPermittedSubclasses:/
-/:$compliance 15:/
-
-InterfaceHeaderPermittedSubClassesAndSubInterfacesopt ::= $empty
-InterfaceHeaderPermittedSubClassesAndSubInterfacesopt -> InterfaceHeaderPermittedSubClassesAndSubInterfaces
-/:$readableName InterfaceHeaderPermittedSubClassesAndSubInterfaces:/
-/:$compliance 15:/
-
-InterfaceHeaderPermittedSubClassesAndSubInterfaces ::= RestrictedIdentifierpermits ClassTypeList
-/.$putCase consumeInterfaceHeaderPermittedSubClassesAndSubInterfaces(); $break ./
-/:$readableName InterfaceHeaderPermittedSubClassesAndSubInterfaces:/
-/:$compliance 15:/
+PermittedTypesopt -> $empty
+PermittedTypesopt ::= 'permits' ClassTypeList
+/.$putCase consumePermittedTypes(); $break ./
+/:$readableName PermittedTypes:/
+/:$compliance 17:/
 
 InterfaceMemberDeclarationsopt ::= $empty
 /. $putCase consumeEmptyInterfaceMemberDeclarationsopt(); $break ./
@@ -3220,3 +3200,4 @@ UNDERSCORE ::= '_'
 $end
 -- need a carriage return after the $end
 
+

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/AbstractCommentParser.java

@@ -1233,7 +1233,7 @@ protected Object parseQualifiedName(boolean reset, boolean allowModule) throws I
 				case TerminalTokens.TokenNamenon_sealed:
 				case TerminalTokens.TokenNamenull:
 				case TerminalTokens.TokenNamepackage:
-				case TerminalTokens.TokenNameRestrictedIdentifierpermits:
+				case TerminalTokens.TokenNamepermits:
 				case TerminalTokens.TokenNameprivate:
 				case TerminalTokens.TokenNameprotected:
 				case TerminalTokens.TokenNamepublic:

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/ParserBasicInformation.java

@@ -21,21 +21,21 @@ public interface ParserBasicInformation {
 	// BEGIN_AUTOGENERATED_REGION
 
 					ERROR_SYMBOL = 140,
-					MAX_NAME_LENGTH = 53,
-					NUM_STATES = 1262,
+					MAX_NAME_LENGTH = 41,
+					NUM_STATES = 1257,
 
 					NT_OFFSET = 140,
 					SCOPE_UBOUND = 321,
 					SCOPE_SIZE = 322,
-					LA_STATE_OFFSET = 18370,
+					LA_STATE_OFFSET = 18382,
 					MAX_LA = 1,
-					NUM_RULES = 956,
+					NUM_RULES = 950,
 					NUM_TERMINALS = 140,
-					NUM_NON_TERMINALS = 440,
-					NUM_SYMBOLS = 580,
-					START_STATE = 1508,
-					EOFT_SYMBOL = 38,
-					EOLT_SYMBOL = 38,
-					ACCEPT_ACTION = 18369,
-					ERROR_ACTION = 18370;
+					NUM_NON_TERMINALS = 436,
+					NUM_SYMBOLS = 576,
+					START_STATE = 1355,
+					EOFT_SYMBOL = 39,
+					EOLT_SYMBOL = 39,
+					ACCEPT_ACTION = 18381,
+					ERROR_ACTION = 18382;
 }

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/RecoveredType.java

@@ -802,7 +802,7 @@ public RecoveredElement updateOnOpeningBrace(int braceStart, int braceEnd){
 			case -1 :
 			case TokenNameextends :
 			case TokenNameimplements :
-			case TokenNameRestrictedIdentifierpermits:
+			case TokenNamepermits:
 			case TokenNameGREATER :
 			case TokenNameRIGHT_SHIFT :
 			case TokenNameUNSIGNED_RIGHT_SHIFT :

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/Scanner.java

@@ -3514,7 +3514,7 @@ else if ((data[index] == 'o')
 								&& (data[++index] == 'i')
 								&& (data[++index] == 't')
 								&& (data[++index] == 's')) {
-							return disambiguatedRestrictedIdentifierpermits(TokenNameRestrictedIdentifierpermits);
+							return disambiguatedToken(TokenNamepermits, this);
 							} else
 							return TokenNameIdentifier;
 					}
@@ -4285,7 +4285,7 @@ public String toStringAction(int act) {
 			return "null"; //$NON-NLS-1$
 		case TokenNamepackage :
 			return "package"; //$NON-NLS-1$
-		case TokenNameRestrictedIdentifierpermits:
+		case TokenNamepermits:
 			return "permits"; //$NON-NLS-1$
 		case TokenNameprivate :
 			return "private"; //$NON-NLS-1$
@@ -4554,7 +4554,7 @@ public static boolean isKeyword(int token) {
 		case TerminalTokens.TokenNameRestrictedIdentifierYield:
 		case TerminalTokens.TokenNameRestrictedIdentifierrecord:
 		case TerminalTokens.TokenNameRestrictedIdentifiersealed:
-		case TerminalTokens.TokenNameRestrictedIdentifierpermits:
+		case TerminalTokens.TokenNamepermits:
 		case TerminalTokens.TokenNameRestrictedIdentifierWhen:
 			// making explicit - not a (restricted) keyword but restricted identifier.
 			//$FALL-THROUGH$
@@ -4624,7 +4624,6 @@ private static class Goal {
 	static int YieldStatementRule = 0;
 	static int SwitchLabelCaseLhsRule = 0;
 	static int[] RestrictedIdentifierSealedRule;
-	static int[] RestrictedIdentifierPermitsRule;
 	static int[] PatternRules;
 
 	static Goal LambdaParameterListGoal;
@@ -4635,18 +4634,15 @@ private static class Goal {
 	static Goal YieldStatementGoal;
 	static Goal SwitchLabelCaseLhsGoal;
 	static Goal RestrictedIdentifierSealedGoal;
-	static Goal RestrictedIdentifierPermitsGoal;
 	static Goal PatternGoal;
 
 	static int[] RestrictedIdentifierSealedFollow =  { TokenNameclass, TokenNameinterface,
 			TokenNameenum, TokenNameRestrictedIdentifierrecord };// Note: enum/record allowed as error flagging rules.
-	static int[] RestrictedIdentifierPermitsFollow =  { TokenNameLBRACE };
 	static int[] PatternCaseLabelFollow = {TokenNameCOLON, TokenNameARROW, TokenNameCOMMA, TokenNameBeginCaseExpr, TokenNameRestrictedIdentifierWhen};
 
 	static {
 
 		List<Integer> ridSealed = new ArrayList<>(2);
-		List<Integer> ridPermits = new ArrayList<>();
 		List<Integer> patternStates = new ArrayList<>();
 		for (int i = 1; i <= ParserBasicInformation.NUM_RULES; i++) {  // 0 == $acc
 			// TODO: Change to switch
@@ -4671,9 +4667,6 @@ private static class Goal {
 			if ("Modifiersopt".equals(Parser.name[Parser.non_terminal_index[Parser.lhs[i]]])) //$NON-NLS-1$
 				ridSealed.add(i);
 			else
-			if ("PermittedSubclasses".equals(Parser.name[Parser.non_terminal_index[Parser.lhs[i]]])) //$NON-NLS-1$
-				ridPermits.add(i);
-			else
 			if ("SwitchLabelCaseLhs".equals(Parser.name[Parser.non_terminal_index[Parser.lhs[i]]])) //$NON-NLS-1$
 				SwitchLabelCaseLhsRule = i;
 			else
@@ -4690,7 +4683,6 @@ private static class Goal {
 				patternStates.add(i);
 		}
 		RestrictedIdentifierSealedRule = ridSealed.stream().mapToInt(Integer :: intValue).toArray(); // overkill but future-proof
-		RestrictedIdentifierPermitsRule = ridPermits.stream().mapToInt(Integer :: intValue).toArray();
 		PatternRules = patternStates.stream().mapToInt(Integer :: intValue).toArray();
 
 		LambdaParameterListGoal =  new Goal(TokenNameARROW, new int[] { TokenNameARROW }, LambdaParameterListRule);
@@ -4701,7 +4693,6 @@ private static class Goal {
 		YieldStatementGoal =       new Goal(TokenNameARROW, new int [0], YieldStatementRule);
 		SwitchLabelCaseLhsGoal =   new Goal(TokenNameARROW, new int [0], SwitchLabelCaseLhsRule);
 		RestrictedIdentifierSealedGoal = new Goal(TokenNameRestrictedIdentifiersealed, RestrictedIdentifierSealedFollow, RestrictedIdentifierSealedRule);
-		RestrictedIdentifierPermitsGoal = new Goal(TokenNameRestrictedIdentifierpermits, RestrictedIdentifierPermitsFollow, RestrictedIdentifierPermitsRule);
 		PatternGoal = new Goal(TokenNameBeginCaseElement, PatternCaseLabelFollow, PatternRules);
 	}
 
@@ -4961,7 +4952,7 @@ protected final boolean maybeAtReferenceExpression() { // Did the '<' we saw jus
 				case TokenNamesuper:      // ? super Context<N>
 				case TokenNameAND:        // T extends Object & Comparable<? super T>
 				case TokenNameimplements: // class A implements I<Z>
-				case TokenNameRestrictedIdentifierpermits: // class A permits I<Z>
+				case TokenNamepermits: // class A permits I<Z>
 				case TokenNamethrows:     // throws Y<Z>
 				case TokenNameAT:         // @Deprecated <T> void foo() {}
 				case TokenNameinstanceof: // if (o instanceof List<E>[])
@@ -4987,7 +4978,7 @@ private final boolean maybeAtEllipsisAnnotationsStart() { // Did the '@' we saw
 		case TokenNameextends:
 		case TokenNamesuper:
 		case TokenNameimplements:
-		case TokenNameRestrictedIdentifierpermits:
+		case TokenNamepermits:
 		case TokenNameDOT:
 		case TokenNameLBRACE:
 		case TokenNameinstanceof:
@@ -5055,7 +5046,7 @@ private boolean mayBeAtASealedRestricedIdentifier(int restrictedIdentifier) {
 	switch (restrictedIdentifier) {
 		case TokenNameRestrictedIdentifiersealed:
 			break;
-		case TokenNameRestrictedIdentifierpermits:
+		case TokenNamepermits:
 			break;
 	}
 	return true;
@@ -5191,20 +5182,7 @@ private boolean disambiguateYieldWithLookAhead() {
 	}
 	return false; // IIE event;
 }
-int disambiguatedRestrictedIdentifierpermits(int restrictedIdentifierToken) {
-	// and here's the kludge
-	if (restrictedIdentifierToken != TokenNameRestrictedIdentifierpermits)
-		return restrictedIdentifierToken;
-	if (!JavaFeature.RECORDS.isSupported(this.complianceLevel, this.previewEnabled))
-		return TokenNameIdentifier;
-
-	return disambiguatesRestrictedIdentifierWithLookAhead(this::mayBeAtASealedRestricedIdentifier,
-			restrictedIdentifierToken, Goal.RestrictedIdentifierPermitsGoal);
-}
 int disambiguatedRestrictedIdentifiersealed(int restrictedIdentifierToken) {
-	// and here's the kludge
-	if (restrictedIdentifierToken != TokenNameRestrictedIdentifiersealed)
-		return restrictedIdentifierToken;
 	if (!JavaFeature.RECORDS.isSupported(this.complianceLevel, this.previewEnabled))
 		return TokenNameIdentifier;
 
@@ -5289,6 +5267,12 @@ private VanguardParser getNewVanguardParser(char[] src) {
 	return vp;
 }
 int disambiguatedToken(int token, Scanner scanner) {
+	if (token == TokenNamepermits) {
+	    if (scanner.sourceLevel < ClassFileConstants.JDK17)
+			return TokenNameIdentifier;
+	    return scanner.activeParser == null || !scanner.activeParser.automatonWillShift(TokenNamepermits) ?
+				TokenNameIdentifier : TokenNamepermits;
+	}
 	final VanguardParser parser = getVanguardParser();
 	parser.scanner.caseStartPosition = this.caseStartPosition;
 	if (token == TokenNameARROW  &&  mayBeAtCaseLabelExpr() &&  scanner.caseStartPosition < scanner.startPosition) {

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/TerminalTokens.java

@@ -41,7 +41,7 @@ public interface TerminalTokens {
 	static boolean isRestrictedKeyword(int tokenType) {
 		return switch (tokenType) {
 			case TokenNameRestrictedIdentifierYield, TokenNameRestrictedIdentifierrecord,TokenNameRestrictedIdentifierWhen,
-					TokenNameRestrictedIdentifiersealed, TokenNameRestrictedIdentifierpermits -> true;
+					TokenNameRestrictedIdentifiersealed, TokenNamepermits -> true;
 			default -> false;
 		};
 	}
@@ -65,7 +65,7 @@ static int getRestrictedKeyword(String text) {
 			case "record"  -> TokenNameRestrictedIdentifierrecord;  //$NON-NLS-1$
 			case "when"    -> TokenNameRestrictedIdentifierWhen;    //$NON-NLS-1$
 			case "sealed"  -> TokenNameRestrictedIdentifiersealed;  //$NON-NLS-1$
-			case "permits" -> TokenNameRestrictedIdentifierpermits; //$NON-NLS-1$
+			case "permits" -> TokenNamepermits; //$NON-NLS-1$
 			default        -> TokenNameNotAToken;
 		};
 	}
@@ -96,7 +96,7 @@ static int getRestrictedKeyword(String text) {
 							TokenNamefor = 86,
 							TokenNamegoto = 139,
 							TokenNameif = 87,
-							TokenNameimplements = 135,
+							TokenNameimplements = 134,
 							TokenNameimport = 112,
 							TokenNameinstanceof = 16,
 							TokenNameint = 113,
@@ -107,12 +107,13 @@ static int getRestrictedKeyword(String text) {
 							TokenNamenon_sealed = 47,
 							TokenNamenull = 57,
 							TokenNamepackage = 91,
+							TokenNamepermits = 135,
 							TokenNameprivate = 48,
 							TokenNameprotected = 49,
 							TokenNamepublic = 50,
 							TokenNamereturn = 88,
 							TokenNameshort = 115,
-							TokenNamestatic = 39,
+							TokenNamestatic = 38,
 							TokenNamestrictfp = 51,
 							TokenNamesuper = 36,
 							TokenNameswitch = 65,
@@ -129,7 +130,7 @@ static int getRestrictedKeyword(String text) {
 							TokenNamemodule = 119,
 							TokenNameopen = 124,
 							TokenNamerequires = 125,
-							TokenNametransitive = 131,
+							TokenNametransitive = 130,
 							TokenNameexports = 126,
 							TokenNameopens = 127,
 							TokenNameto = 136,
@@ -200,15 +201,14 @@ static int getRestrictedKeyword(String text) {
 							TokenNameBeginTypeArguments = 90,
 							TokenNameElidedSemicolonAndRightBrace = 72,
 							TokenNameAT308 = 28,
-							TokenNameAT308DOTDOTDOT = 132,
+							TokenNameAT308DOTDOTDOT = 131,
 							TokenNameBeginCaseExpr = 73,
 							TokenNameRestrictedIdentifierYield = 81,
 							TokenNameRestrictedIdentifierrecord = 76,
 							TokenNameRestrictedIdentifiersealed = 43,
-							TokenNameRestrictedIdentifierpermits = 130,
-							TokenNameBeginCaseElement = 133,
-							TokenNameRestrictedIdentifierWhen = 134,
+							TokenNameBeginCaseElement = 132,
+							TokenNameRestrictedIdentifierWhen = 133,
 							TokenNameUNDERSCORE = 34,
-							TokenNameEOF = 38,
+							TokenNameEOF = 39,
 							TokenNameERROR = 140;
 }

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/readableNames.props

@@ -70,8 +70,6 @@ ClassHeaderImplements=ClassHeaderImplements
 ClassHeaderImplementsopt=ClassHeaderImplements
 ClassHeaderName1=ClassHeaderName
 ClassHeaderName=ClassHeaderName
-ClassHeaderPermittedSubclasses=ClassHeaderPermittedSubclasses
-ClassHeaderPermittedSubclassesopt=ClassHeaderPermittedSubclasses
 ClassInstanceCreationExpression=ClassInstanceCreationExpression
 ClassInstanceCreationExpressionName=ClassInstanceCreationExpressionName
 ClassMemberDeclaration=ClassMemberDeclaration
@@ -191,8 +189,6 @@ InterfaceHeaderExtends=InterfaceHeaderExtends
 InterfaceHeaderExtendsopt=InterfaceHeaderExtends
 InterfaceHeaderName1=InterfaceHeaderName
 InterfaceHeaderName=InterfaceHeaderName
-InterfaceHeaderPermittedSubClassesAndSubInterfaces=InterfaceHeaderPermittedSubClassesAndSubInterfaces
-InterfaceHeaderPermittedSubClassesAndSubInterfacesopt=InterfaceHeaderPermittedSubClassesAndSubInterfaces
 InterfaceMemberDeclaration=InterfaceMemberDeclaration
 InterfaceMemberDeclarations=InterfaceMemberDeclarations
 InterfaceMemberDeclarationsopt=InterfaceMemberDeclarations
@@ -254,7 +250,7 @@ PackageDeclarationName=PackageDeclarationName
 ParenthesizedCastNameAndBounds=ParenthesizedCastNameAndBounds
 ParenthesizedLambdaParameterList=ParenthesizedLambdaParameterList
 Pattern=Pattern
-PermittedSubclasses=PermittedSubclasses
+PermittedTypesopt=PermittedTypes
 PostDecrementExpression=PostDecrementExpression
 PostIncrementExpression=PostIncrementExpression
 PostfixExpression=Expression

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java

@@ -5221,7 +5221,7 @@ private boolean isRestrictedIdentifier(int token) {
 		case TerminalTokens.TokenNameRestrictedIdentifierYield:
 		case TerminalTokens.TokenNameRestrictedIdentifierrecord:
 		case TerminalTokens.TokenNameRestrictedIdentifiersealed:
-		case TerminalTokens.TokenNameRestrictedIdentifierpermits:
+		case TerminalTokens.TokenNamepermits:
 		case TerminalTokens.TokenNameRestrictedIdentifierWhen:
 			return true;
 		default: return false;
@@ -5284,7 +5284,7 @@ private boolean isKeyword(int token) {
 		case TerminalTokens.TokenNameRestrictedIdentifierYield:
 		case TerminalTokens.TokenNameRestrictedIdentifierrecord:
 		case TerminalTokens.TokenNameRestrictedIdentifiersealed:
-		case TerminalTokens.TokenNameRestrictedIdentifierpermits:
+		case TerminalTokens.TokenNamepermits:
 		case TerminalTokens.TokenNameRestrictedIdentifierWhen:
 			// making explicit - not a (restricted) keyword but restricted identifier.
 			//$FALL-THROUGH$