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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.
Imports Microsoft.CodeAnalysis
Imports Microsoft.CodeAnalysis.VisualBasic
Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
Namespace Microsoft.CodeAnalysis.VisualBasic.ExtractMethod
Partial Friend NotInheritable Class VisualBasicExtractMethodService
Partial Friend Class VisualBasicMethodExtractor
Partial Private MustInherit Class VisualBasicCodeGenerator
Private Class CallSiteContainerRewriter
Inherits VisualBasicSyntaxRewriter
Private ReadOnly _outmostCallSiteContainer As SyntaxNode
Private ReadOnly _statementsOrFieldToInsert As IEnumerable(Of StatementSyntax)
Private ReadOnly _variableToRemoveMap As HashSet(Of SyntaxAnnotation)
Private ReadOnly _firstStatementOrFieldToReplace As StatementSyntax
Private ReadOnly _lastStatementOrFieldToReplace As StatementSyntax
Private Shared ReadOnly s_removeAnnotation As SyntaxAnnotation = New SyntaxAnnotation()
Public Sub New(outmostCallSiteContainer As SyntaxNode,
variableToRemoveMap As HashSet(Of SyntaxAnnotation),
firstStatementOrFieldToReplace As StatementSyntax,
lastStatementOrFieldToReplace As StatementSyntax,
statementsOrFieldToInsert As IEnumerable(Of StatementSyntax))
Contract.ThrowIfNull(outmostCallSiteContainer)
Contract.ThrowIfNull(variableToRemoveMap)
Contract.ThrowIfNull(firstStatementOrFieldToReplace)
Contract.ThrowIfNull(lastStatementOrFieldToReplace)
Contract.ThrowIfTrue(statementsOrFieldToInsert.IsEmpty())
Me._outmostCallSiteContainer = outmostCallSiteContainer
Me._variableToRemoveMap = variableToRemoveMap
Me._statementsOrFieldToInsert = statementsOrFieldToInsert
Me._firstStatementOrFieldToReplace = firstStatementOrFieldToReplace
Me._lastStatementOrFieldToReplace = lastStatementOrFieldToReplace
Contract.ThrowIfFalse(Me._firstStatementOrFieldToReplace.Parent Is Me._lastStatementOrFieldToReplace.Parent)
End Sub
Public Function Generate() As SyntaxNode
Dim result = Visit(Me._outmostCallSiteContainer)
' remove any nodes annotated for removal
If result.ContainsAnnotations Then
Dim nodesToRemove = result.DescendantNodes(Function(n) n.ContainsAnnotations).Where(Function(n) n.HasAnnotation(s_removeAnnotation))
result = result.RemoveNodes(nodesToRemove, SyntaxRemoveOptions.KeepNoTrivia)
End If
Return result
End Function
Private ReadOnly Property ContainerOfStatementsOrFieldToReplace() As SyntaxNode
Get
Return Me._firstStatementOrFieldToReplace.Parent
End Get
End Property
Public Overrides Function VisitLocalDeclarationStatement(node As LocalDeclarationStatementSyntax) As SyntaxNode
node = CType(MyBase.VisitLocalDeclarationStatement(node), LocalDeclarationStatementSyntax)
Dim expressionStatements = New List(Of StatementSyntax)()
Dim variableDeclarators = New List(Of VariableDeclaratorSyntax)()
Dim triviaList = New List(Of SyntaxTrivia)()
If Not Me._variableToRemoveMap.ProcessLocalDeclarationStatement(node, expressionStatements, variableDeclarators, triviaList) Then
Contract.ThrowIfFalse(expressionStatements.Count = 0)
Return node
End If
Contract.ThrowIfFalse(expressionStatements.Count = 0)
If variableDeclarators.Count = 0 AndAlso
triviaList.Any(Function(t) t.Kind <> SyntaxKind.WhitespaceTrivia AndAlso t.Kind <> SyntaxKind.EndOfLineTrivia) Then
' well, there are trivia associated with the node.
' we can't just delete the node since then, we will lose
' the trivia. unfortunately, it is not easy to attach the trivia
' to next token. for now, create an empty statement and associate the
' trivia to the statement
' TODO : think about a way to trivia attached to next token
Return SyntaxFactory.EmptyStatement(SyntaxFactory.Token(SyntaxKind.EmptyToken).WithLeadingTrivia(SyntaxFactory.TriviaList(triviaList)))
End If
' return survived var decls
If variableDeclarators.Count > 0 Then
Return SyntaxFactory.LocalDeclarationStatement(
node.Modifiers,
SyntaxFactory.SeparatedList(variableDeclarators)).WithPrependedLeadingTrivia(triviaList)
End If
Return node.WithAdditionalAnnotations(s_removeAnnotation)
End Function
Public Overrides Function VisitMethodBlock(node As MethodBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
' make sure we visit nodes under the block
Return MyBase.VisitMethodBlock(node)
End If
Return node.WithSubOrFunctionStatement(ReplaceStatementIfNeeded(node.SubOrFunctionStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitConstructorBlock(node As ConstructorBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
' make sure we visit nodes under the block
Return MyBase.VisitConstructorBlock(node)
End If
Return node.WithSubNewStatement(ReplaceStatementIfNeeded(node.SubNewStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitOperatorBlock(node As OperatorBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
' make sure we visit nodes under the block
Return MyBase.VisitOperatorBlock(node)
End If
Return node.WithOperatorStatement(ReplaceStatementIfNeeded(node.OperatorStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitAccessorBlock(node As AccessorBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
' make sure we visit nodes under the block
Return MyBase.VisitAccessorBlock(node)
End If
Return node.WithAccessorStatement(ReplaceStatementIfNeeded(node.AccessorStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitWhileBlock(node As WhileBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
' make sure we visit nodes under the switch section
Return MyBase.VisitWhileBlock(node)
End If
Return node.WithWhileStatement(ReplaceStatementIfNeeded(node.WhileStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitUsingBlock(node As UsingBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitUsingBlock(node)
End If
Return node.WithUsingStatement(ReplaceStatementIfNeeded(node.UsingStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitSyncLockBlock(node As SyncLockBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitSyncLockBlock(node)
End If
Return node.WithSyncLockStatement(ReplaceStatementIfNeeded(node.SyncLockStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitWithBlock(node As WithBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitWithBlock(node)
End If
Return node.WithWithStatement(ReplaceStatementIfNeeded(node.WithStatement)).
WithStatements(ReplaceStatementsIfNeeded(node.Statements))
End Function
Public Overrides Function VisitSingleLineIfStatement(node As SingleLineIfStatementSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitSingleLineIfStatement(node)
End If
Return SyntaxFactory.SingleLineIfStatement(node.IfKeyword,
node.Condition,
node.ThenKeyword,
VisitList(ReplaceStatementsIfNeeded(node.Statements, colon:=True)),
node.ElseClause)
End Function
Public Overrides Function VisitSingleLineElseClause(node As SingleLineElseClauseSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitSingleLineElseClause(node)
End If
Return SyntaxFactory.SingleLineElseClause(node.ElseKeyword, VisitList(ReplaceStatementsIfNeeded(node.Statements, colon:=True)))
End Function
Public Overrides Function VisitMultiLineIfBlock(node As MultiLineIfBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitMultiLineIfBlock(node)
End If
Return node.WithIfStatement(ReplaceStatementIfNeeded(node.IfStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitElseBlock(node As ElseBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitElseBlock(node)
End If
Return node.WithElseStatement(ReplaceStatementIfNeeded(node.ElseStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitElseIfBlock(node As ElseIfBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitElseIfBlock(node)
End If
Return node.WithElseIfStatement(ReplaceStatementIfNeeded(node.ElseIfStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitTryBlock(node As TryBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitTryBlock(node)
End If
Return node.WithTryStatement(ReplaceStatementIfNeeded(node.TryStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitCatchBlock(node As CatchBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitCatchBlock(node)
End If
Return node.WithCatchStatement(ReplaceStatementIfNeeded(node.CatchStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitFinallyBlock(node As FinallyBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitFinallyBlock(node)
End If
Return node.WithFinallyStatement(ReplaceStatementIfNeeded(node.FinallyStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitSelectBlock(node As SelectBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitSelectBlock(node)
End If
Return node.WithSelectStatement(ReplaceStatementIfNeeded(node.SelectStatement)).
WithCaseBlocks(VisitList(node.CaseBlocks)).
WithEndSelectStatement(ReplaceStatementIfNeeded(node.EndSelectStatement))
End Function
Public Overrides Function VisitCaseBlock(node As CaseBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitCaseBlock(node)
End If
Return node.WithCaseStatement(ReplaceStatementIfNeeded(node.CaseStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements)))
End Function
Public Overrides Function VisitDoLoopBlock(node As DoLoopBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitDoLoopBlock(node)
End If
Return node.WithDoStatement(ReplaceStatementIfNeeded(node.DoStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements))).
WithLoopStatement(ReplaceStatementIfNeeded(node.LoopStatement))
End Function
Public Overrides Function VisitForBlock(node As ForBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitForBlock(node)
End If
Return node.WithForStatement(ReplaceStatementIfNeeded(node.ForStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements))).
WithNextStatement(ReplaceStatementIfNeeded(node.NextStatement))
End Function
Public Overrides Function VisitForEachBlock(node As ForEachBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitForEachBlock(node)
End If
Return node.WithForEachStatement(ReplaceStatementIfNeeded(node.ForEachStatement)).
WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements))).
WithNextStatement(ReplaceStatementIfNeeded(node.NextStatement))
End Function
Public Overrides Function VisitSingleLineLambdaExpression(node As SingleLineLambdaExpressionSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitSingleLineLambdaExpression(node)
End If
Dim body = SyntaxFactory.SingletonList(DirectCast(node.Body, StatementSyntax))
Return node.WithBody(VisitList(ReplaceStatementsIfNeeded(body, colon:=True)).First()).
WithSubOrFunctionHeader(ReplaceStatementIfNeeded(node.SubOrFunctionHeader))
End Function
Public Overrides Function VisitMultiLineLambdaExpression(node As MultiLineLambdaExpressionSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
Return MyBase.VisitMultiLineLambdaExpression(node)
End If
Return node.WithStatements(VisitList(ReplaceStatementsIfNeeded(node.Statements))).
WithSubOrFunctionHeader(ReplaceStatementIfNeeded(node.SubOrFunctionHeader))
End Function
Private Function ReplaceStatementIfNeeded(Of T As StatementSyntax)(statement As T) As T
Contract.ThrowIfNull(statement)
' if all three same
If (statement IsNot _firstStatementOrFieldToReplace) OrElse (Me._firstStatementOrFieldToReplace IsNot Me._lastStatementOrFieldToReplace) Then
Return statement
End If
Contract.ThrowIfFalse(Me._statementsOrFieldToInsert.Count() = 1)
Return CType(Me._statementsOrFieldToInsert.Single(), T)
End Function
Private Function ReplaceStatementsIfNeeded(statements As SyntaxList(Of StatementSyntax), Optional colon As Boolean = False) As SyntaxList(Of StatementSyntax)
Dim newStatements = New List(Of StatementSyntax)(statements)
Dim firstStatementIndex = newStatements.FindIndex(Function(s) s Is Me._firstStatementOrFieldToReplace)
' looks like statements belong to parent's Begin statement. there is nothing we need to do here.
If firstStatementIndex < 0 Then
Contract.ThrowIfFalse(Me._firstStatementOrFieldToReplace Is Me._lastStatementOrFieldToReplace)
Return statements
End If
Dim lastStatementIndex = newStatements.FindIndex(Function(s) s Is Me._lastStatementOrFieldToReplace)
Contract.ThrowIfFalse(lastStatementIndex >= 0)
Contract.ThrowIfFalse(firstStatementIndex <= lastStatementIndex)
' okay, this visit contains the statement
' remove statement that must be removed
statements = statements.RemoveRange(firstStatementIndex, lastStatementIndex - firstStatementIndex + 1)
' insert new statements
Return statements.InsertRange(firstStatementIndex, Join(Me._statementsOrFieldToInsert, colon).ToArray())
End Function
Private Shared Function Join(statements As IEnumerable(Of StatementSyntax), colon As Boolean) As IEnumerable(Of StatementSyntax)
If Not colon Then
Return statements
End If
Dim removeEndOfLine = Function(t As SyntaxTrivia) Not t.IsElastic() AndAlso t.Kind <> SyntaxKind.EndOfLineTrivia
Dim i = 0
Dim count = statements.Count()
Dim trivia = SyntaxFactory.ColonTrivia(SyntaxFacts.GetText(SyntaxKind.ColonTrivia))
Dim newStatements = New List(Of StatementSyntax)
For Each statement In statements
statement = statement.WithLeadingTrivia(statement.GetLeadingTrivia().Where(removeEndOfLine))
If i < count - 1 Then
statement = statement.WithTrailingTrivia(statement.GetTrailingTrivia().Where(removeEndOfLine).Concat(trivia))
End If
newStatements.Add(statement)
i += 1
Next
Return newStatements
End Function
Public Overrides Function VisitModuleBlock(ByVal node As ModuleBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
' make sure we visit nodes under the block
Return MyBase.VisitModuleBlock(node)
End If
Return node.WithMembers(VisitList(ReplaceStatementsIfNeeded(node.Members)))
End Function
Public Overrides Function VisitClassBlock(ByVal node As ClassBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
' make sure we visit nodes under the block
Return MyBase.VisitClassBlock(node)
End If
Return node.WithMembers(VisitList(ReplaceStatementsIfNeeded(node.Members)))
End Function
Public Overrides Function VisitStructureBlock(ByVal node As StructureBlockSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
' make sure we visit nodes under the block
Return MyBase.VisitStructureBlock(node)
End If
Return node.WithMembers(VisitList(ReplaceStatementsIfNeeded(node.Members)))
End Function
Public Overrides Function VisitCompilationUnit(node As CompilationUnitSyntax) As SyntaxNode
If node IsNot Me.ContainerOfStatementsOrFieldToReplace Then
' make sure we visit nodes under the block
Return MyBase.VisitCompilationUnit(node)
End If
Return node.WithMembers(VisitList(ReplaceStatementsIfNeeded(node.Members)))
End Function
End Class
End Class
End Class
End Class
End Namespace
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