| // Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| import '../../scanner/token.dart' show Keyword, Token; |
| import '../messages.dart' as fasta; |
| import 'formal_parameter_kind.dart'; |
| import 'member_kind.dart' show MemberKind; |
| import 'parser.dart' show Parser; |
| import 'util.dart' show optional; |
| |
| bool isModifier(Token token) { |
| if (!token.isModifier) { |
| return false; |
| } else if (token.type.isBuiltIn) { |
| // A built-in keyword can only be a modifier as long as it is |
| // followed by another keyword or an identifier. Otherwise, it is the |
| // identifier. |
| // |
| // For example, `external` is a modifier in this declaration: |
| // external Foo foo(); |
| // but is the identifier in this declaration |
| // external() => true; |
| // and in |
| // for (final external in list) { } |
| Token next = token.next; |
| Keyword keyword = next.keyword; |
| if (keyword == null && !next.isIdentifier || keyword == Keyword.IN) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /// This class is used to parse modifiers in most locations where modifiers |
| /// can occur, but does not call handleModifier or handleModifiers. |
| class ModifierRecoveryContext { |
| final Parser parser; |
| Token abstractToken; |
| Token constToken; |
| Token covariantToken; |
| Token externalToken; |
| Token finalToken; |
| Token lateToken; |
| Token requiredToken; |
| Token staticToken; |
| Token varToken; |
| |
| // Set `true` when parsing modifiers after the `factory` token. |
| bool afterFactory = false; |
| |
| // TODO(danrubel): Replace [ModifierRecoveryContext] and [ModifierContext] |
| // with this class. |
| |
| ModifierRecoveryContext(this.parser); |
| |
| set staticOrCovariant(Token staticOrCovariant) { |
| if (staticOrCovariant == null) { |
| covariantToken = null; |
| staticToken = null; |
| } else if (optional('covariant', staticOrCovariant)) { |
| covariantToken = staticOrCovariant; |
| staticToken = null; |
| } else if (optional('static', staticOrCovariant)) { |
| covariantToken = null; |
| staticToken = staticOrCovariant; |
| } else { |
| throw "Internal error: " |
| "Unexpected staticOrCovariant '$staticOrCovariant'."; |
| } |
| } |
| |
| Token get varFinalOrConst => varToken ?? finalToken ?? constToken; |
| |
| set varFinalOrConst(Token varFinalOrConst) { |
| if (varFinalOrConst == null) { |
| varToken = null; |
| finalToken = null; |
| constToken = null; |
| } else if (optional('var', varFinalOrConst)) { |
| varToken = varFinalOrConst; |
| finalToken = null; |
| constToken = null; |
| } else if (optional('final', varFinalOrConst)) { |
| varToken = null; |
| finalToken = varFinalOrConst; |
| constToken = null; |
| } else if (optional('const', varFinalOrConst)) { |
| varToken = null; |
| finalToken = null; |
| constToken = varFinalOrConst; |
| } else { |
| throw "Internal error: Unexpected varFinalOrConst '$varFinalOrConst'."; |
| } |
| } |
| |
| /// Parse modifiers for class methods and fields. |
| Token parseClassMemberModifiers(Token token) { |
| token = parseModifiers(token); |
| if (abstractToken != null) { |
| parser.reportRecoverableError( |
| abstractToken, fasta.messageAbstractClassMember); |
| } |
| reportExtraneousModifier(requiredToken); |
| return token; |
| } |
| |
| /// Parse modifiers for formal parameters. |
| Token parseFormalParameterModifiers( |
| Token token, FormalParameterKind parameterKind, MemberKind memberKind) { |
| token = parseModifiers(token); |
| |
| if (parameterKind != FormalParameterKind.optionalNamed) { |
| reportExtraneousModifier(requiredToken); |
| } |
| if (memberKind == MemberKind.StaticMethod || |
| memberKind == MemberKind.TopLevelMethod) { |
| reportExtraneousModifier(this.covariantToken); |
| this.covariantToken = null; |
| } |
| if (constToken != null) { |
| reportExtraneousModifier(constToken); |
| } else if (memberKind == MemberKind.GeneralizedFunctionType) { |
| if (varFinalOrConst != null) { |
| parser.reportRecoverableError( |
| varFinalOrConst, fasta.messageFunctionTypedParameterVar); |
| } |
| } |
| reportExtraneousModifier(abstractToken); |
| reportExtraneousModifier(externalToken); |
| reportExtraneousModifier(lateToken); |
| reportExtraneousModifier(staticToken); |
| return token; |
| } |
| |
| /// Parse modifiers after the `factory` token. |
| Token parseModifiersAfterFactory(Token token) { |
| afterFactory = true; |
| token = parseModifiers(token); |
| if (abstractToken != null) { |
| parser.reportRecoverableError( |
| abstractToken, fasta.messageAbstractClassMember); |
| } |
| reportExtraneousModifier(lateToken); |
| reportExtraneousModifier(requiredToken); |
| return token; |
| } |
| |
| /// Parse modifiers for top level functions and fields. |
| Token parseTopLevelModifiers(Token token) { |
| token = parseModifiers(token); |
| reportExtraneousModifier(abstractToken); |
| reportExtraneousModifier(covariantToken); |
| reportExtraneousModifier(requiredToken); |
| reportExtraneousModifier(staticToken); |
| return token; |
| } |
| |
| /// Parse modifiers for variable declarations. |
| Token parseVariableDeclarationModifiers(Token token) { |
| token = parseModifiers(token); |
| reportExtraneousModifier(abstractToken); |
| reportExtraneousModifier(covariantToken); |
| reportExtraneousModifier(externalToken); |
| reportExtraneousModifier(requiredToken); |
| reportExtraneousModifier(staticToken); |
| return token; |
| } |
| |
| /// Parse modifiers during recovery when modifiers are out of order |
| /// or invalid. Typically clients call methods like |
| /// [parseClassMemberModifiers] which in turn calls this method, |
| /// rather than calling this method directly. |
| /// |
| /// The various modifier token parameters represent tokens of modifiers |
| /// that have already been parsed prior to recovery. The [staticOrCovariant] |
| /// parameter is for convenience if caller has a token that may be either |
| /// `static` or `covariant`. The first non-null parameter of |
| /// [staticOrCovariant], [staticToken], or [covariantToken] will be used, |
| /// in that order, and the others ignored. |
| Token parseModifiers(Token token) { |
| // Process invalid and out-of-order modifiers |
| Token next = token.next; |
| while (true) { |
| final value = next.stringValue; |
| if (isModifier(next)) { |
| if (identical('abstract', value)) { |
| token = parseAbstract(token); |
| } else if (identical('const', value)) { |
| token = parseConst(token); |
| } else if (identical('covariant', value)) { |
| token = parseCovariant(token); |
| } else if (identical('external', value)) { |
| token = parseExternal(token); |
| } else if (identical('final', value)) { |
| token = parseFinal(token); |
| } else if (identical('late', value)) { |
| token = parseLate(token); |
| } else if (identical('required', value)) { |
| token = parseRequired(token); |
| } else if (identical('static', value)) { |
| token = parseStatic(token); |
| } else if (identical('var', value)) { |
| token = parseVar(token); |
| } else { |
| throw 'Internal Error: Unhandled modifier: $value'; |
| } |
| } else if (afterFactory && identical('factory', value)) { |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| token = next; |
| } else { |
| break; |
| } |
| next = token.next; |
| } |
| return token; |
| } |
| |
| Token parseAbstract(Token token) { |
| Token next = token.next; |
| assert(optional('abstract', next)); |
| if (abstractToken == null) { |
| abstractToken = next; |
| return next; |
| } |
| |
| // Recovery |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| return next; |
| } |
| |
| Token parseConst(Token token) { |
| Token next = token.next; |
| assert(optional('const', next)); |
| if (varFinalOrConst == null && covariantToken == null) { |
| constToken = next; |
| |
| if (afterFactory) { |
| reportModifierOutOfOrder(next, 'factory'); |
| } else if (lateToken != null) { |
| reportConflictingModifiers(next, lateToken); |
| } |
| return next; |
| } |
| |
| // Recovery |
| if (constToken != null) { |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| } else if (covariantToken != null) { |
| reportConflictingModifiers(next, covariantToken); |
| } else if (finalToken != null) { |
| parser.reportRecoverableError(next, fasta.messageConstAndFinal); |
| } else if (varToken != null) { |
| reportConflictingModifiers(next, varToken); |
| } else { |
| throw 'Internal Error: Unexpected varFinalOrConst: $varFinalOrConst'; |
| } |
| return next; |
| } |
| |
| Token parseCovariant(Token token) { |
| Token next = token.next; |
| assert(optional('covariant', next)); |
| if (constToken == null && |
| covariantToken == null && |
| staticToken == null && |
| !afterFactory) { |
| covariantToken = next; |
| |
| if (varToken != null) { |
| reportModifierOutOfOrder(next, varToken.lexeme); |
| } else if (finalToken != null) { |
| reportModifierOutOfOrder(next, finalToken.lexeme); |
| } else if (lateToken != null) { |
| reportModifierOutOfOrder(next, lateToken.lexeme); |
| } |
| return next; |
| } |
| |
| // Recovery |
| if (covariantToken != null) { |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| } else if (afterFactory) { |
| reportExtraneousModifier(next); |
| } else if (constToken != null) { |
| reportConflictingModifiers(next, constToken); |
| } else if (staticToken != null) { |
| parser.reportRecoverableError(next, fasta.messageCovariantAndStatic); |
| } else { |
| throw 'Internal Error: Unhandled recovery: $next'; |
| } |
| return next; |
| } |
| |
| Token parseExternal(Token token) { |
| Token next = token.next; |
| assert(optional('external', next)); |
| if (externalToken == null) { |
| externalToken = next; |
| |
| if (afterFactory) { |
| reportModifierOutOfOrder(next, 'factory'); |
| } else if (constToken != null) { |
| reportModifierOutOfOrder(next, constToken.lexeme); |
| } else if (staticToken != null) { |
| reportModifierOutOfOrder(next, staticToken.lexeme); |
| } else if (lateToken != null) { |
| reportModifierOutOfOrder(next, lateToken.lexeme); |
| } |
| return next; |
| } |
| |
| // Recovery |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| return next; |
| } |
| |
| Token parseFinal(Token token) { |
| Token next = token.next; |
| assert(optional('final', next)); |
| if (varFinalOrConst == null && !afterFactory) { |
| finalToken = next; |
| return next; |
| } |
| |
| // Recovery |
| if (finalToken != null) { |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| } else if (afterFactory) { |
| reportExtraneousModifier(next); |
| } else if (constToken != null) { |
| parser.reportRecoverableError(next, fasta.messageConstAndFinal); |
| } else if (varToken != null) { |
| parser.reportRecoverableError(next, fasta.messageFinalAndVar); |
| } else if (lateToken != null) { |
| reportModifierOutOfOrder(next, lateToken.lexeme); |
| } else { |
| throw 'Internal Error: Unexpected varFinalOrConst: $varFinalOrConst'; |
| } |
| return next; |
| } |
| |
| Token parseLate(Token token) { |
| Token next = token.next; |
| assert(optional('late', next)); |
| if (lateToken == null) { |
| lateToken = next; |
| |
| if (constToken != null) { |
| reportConflictingModifiers(next, constToken); |
| } else if (varToken != null) { |
| reportConflictingModifiers(next, varToken); |
| } else if (finalToken != null) { |
| reportModifierOutOfOrder(next, finalToken.lexeme); |
| } |
| return next; |
| } |
| |
| // Recovery |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| return next; |
| } |
| |
| Token parseRequired(Token token) { |
| Token next = token.next; |
| assert(optional('required', next)); |
| if (requiredToken == null) { |
| requiredToken = next; |
| |
| if (constToken != null) { |
| reportModifierOutOfOrder(requiredToken, constToken.lexeme); |
| } else if (covariantToken != null) { |
| reportModifierOutOfOrder(requiredToken, covariantToken.lexeme); |
| } else if (finalToken != null) { |
| reportModifierOutOfOrder(requiredToken, finalToken.lexeme); |
| } else if (varToken != null) { |
| reportModifierOutOfOrder(requiredToken, varToken.lexeme); |
| } |
| return next; |
| } |
| |
| // Recovery |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| return next; |
| } |
| |
| Token parseStatic(Token token) { |
| Token next = token.next; |
| assert(optional('static', next)); |
| if (covariantToken == null && staticToken == null && !afterFactory) { |
| staticToken = next; |
| |
| if (constToken != null) { |
| reportModifierOutOfOrder(next, constToken.lexeme); |
| } else if (finalToken != null) { |
| reportModifierOutOfOrder(next, finalToken.lexeme); |
| } else if (varToken != null) { |
| reportModifierOutOfOrder(next, varToken.lexeme); |
| } else if (lateToken != null) { |
| reportModifierOutOfOrder(next, lateToken.lexeme); |
| } |
| return next; |
| } |
| |
| // Recovery |
| if (covariantToken != null) { |
| parser.reportRecoverableError(next, fasta.messageCovariantAndStatic); |
| } else if (staticToken != null) { |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| } else if (afterFactory) { |
| reportExtraneousModifier(next); |
| } else { |
| throw 'Internal Error: Unhandled recovery: $next'; |
| } |
| return next; |
| } |
| |
| Token parseVar(Token token) { |
| Token next = token.next; |
| assert(optional('var', next)); |
| if (varFinalOrConst == null && !afterFactory) { |
| varToken = next; |
| |
| if (lateToken != null) { |
| reportConflictingModifiers(next, lateToken); |
| } |
| return next; |
| } |
| |
| // Recovery |
| if (varToken != null) { |
| parser.reportRecoverableErrorWithToken( |
| next, fasta.templateDuplicatedModifier); |
| } else if (afterFactory) { |
| reportExtraneousModifier(next); |
| } else if (constToken != null) { |
| reportConflictingModifiers(next, constToken); |
| } else if (finalToken != null) { |
| parser.reportRecoverableError(next, fasta.messageFinalAndVar); |
| } else { |
| throw 'Internal Error: Unexpected varFinalOrConst: $varFinalOrConst'; |
| } |
| return next; |
| } |
| |
| void reportConflictingModifiers(Token modifier, Token earlierModifier) { |
| parser.reportRecoverableError( |
| modifier, |
| fasta.templateConflictingModifiers |
| .withArguments(modifier.lexeme, earlierModifier.lexeme)); |
| } |
| |
| void reportExtraneousModifier(Token modifier) { |
| if (modifier != null) { |
| parser.reportRecoverableErrorWithToken( |
| modifier, fasta.templateExtraneousModifier); |
| } |
| } |
| |
| void reportModifierOutOfOrder(Token modifier, String beforeModifier) { |
| parser.reportRecoverableError( |
| modifier, |
| fasta.templateModifierOutOfOrder |
| .withArguments(modifier.lexeme, beforeModifier)); |
| } |
| } |