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' Licensed to the .NET Foundation under one or more agreements.
' The .NET Foundation licenses this file to you under the MIT license.
' See the LICENSE file in the project root for more information.
'-----------------------------------------------------------------------------
' Contains the definition of the BlockContext
'-----------------------------------------------------------------------------
Imports Microsoft.CodeAnalysis.Syntax.InternalSyntax
Imports Microsoft.CodeAnalysis.Text
Imports Microsoft.CodeAnalysis.VisualBasic.Symbols
Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
Imports InternalSyntaxFactory = Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax.SyntaxFactory
Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
Friend NotInheritable Class SelectBlockContext
Inherits ExecutableStatementContext
Private ReadOnly _caseBlocks As SyntaxListBuilder(Of CaseBlockSyntax)
Friend Sub New(statement As StatementSyntax, prevContext As BlockContext)
MyBase.New(SyntaxKind.SelectBlock, statement, prevContext)
Debug.Assert(statement.Kind = SyntaxKind.SelectStatement)
_caseBlocks = _parser._pool.Allocate(Of CaseBlockSyntax)()
End Sub
Friend Overrides Function ProcessSyntax(node As VisualBasicSyntaxNode) As BlockContext
Select Case node.Kind
Case SyntaxKind.CaseStatement
Return New CaseBlockContext(SyntaxKind.CaseBlock, DirectCast(node, StatementSyntax), Me)
Case SyntaxKind.CaseElseStatement
Return New CaseBlockContext(SyntaxKind.CaseElseBlock, DirectCast(node, StatementSyntax), Me)
Case SyntaxKind.CaseBlock,
SyntaxKind.CaseElseBlock
_caseBlocks.Add(DirectCast(node, CaseBlockSyntax))
Case Else
' TODO - davidsch
' 1. Dev10 the error is reported on the keyword that introduces the statement. If the error is
' reported here it is easier to mark the whole statement and much harder to just mark the keyword.
' 2. The bad statement is going into an empty case block. Is this the correct error model. Do we need
' a BadCaseStatement? Compile a list of all uses of missing statements.
node = Parser.ReportSyntaxError(node, ERRID.ERR_ExpectedCase)
Dim caseStmt = SyntaxFactory.CaseStatement(InternalSyntaxFactory.MissingKeyword(SyntaxKind.CaseKeyword), New CodeAnalysis.Syntax.InternalSyntax.SeparatedSyntaxList(Of CaseClauseSyntax)())
Dim context = New CaseBlockContext(SyntaxKind.CaseBlock, caseStmt, Me)
' Previously we explicitly added a missing terminator. Now, missing terminators are added automatically if a statement
' is added next to a statement.
Return context.ProcessSyntax(node)
End Select
Return Me
End Function
Friend Overrides Function TryLinkSyntax(node As VisualBasicSyntaxNode, ByRef newContext As BlockContext) As LinkResult
newContext = Nothing
If KindEndsBlock(node.Kind) Then
Return UseSyntax(node, newContext)
End If
Select Case node.Kind
Case _
SyntaxKind.CaseStatement,
SyntaxKind.CaseElseStatement
Return UseSyntax(node, newContext)
' Reuse SyntaxKind.CaseBlock but do not reuse CaseElseBlock. These need to be crumbled so that the
' error check for multiple case else statements is done.
Case SyntaxKind.CaseBlock
Return UseSyntax(node, newContext) Or LinkResult.SkipTerminator
Case Else
' Don't reuse other statements. It is always an error and if a block statement is reused then the error is attached to the
' block instead of the statement.
Return LinkResult.NotUsed
End Select
End Function
Friend Overrides Function CreateBlockSyntax(endStmt As StatementSyntax) As VisualBasicSyntaxNode
Debug.Assert(BeginStatement IsNot Nothing)
Dim beginBlockStmt As SelectStatementSyntax = Nothing
Dim endBlockStmt As EndBlockStatementSyntax = DirectCast(endStmt, EndBlockStatementSyntax)
GetBeginEndStatements(beginBlockStmt, endBlockStmt)
Dim result = SyntaxFactory.SelectBlock(beginBlockStmt, _caseBlocks.ToList, endBlockStmt)
_parser._pool.Free(_caseBlocks)
FreeStatements()
Return result
End Function
End Class
End Namespace
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