private static ImmutableArray <IfAnalysis> Analyze(
ExpressionStatementSyntax expressionStatement,
IfStatementSyntax ifStatement,
IfAnalysisOptions options,
SemanticModel semanticModel,
CancellationToken cancellationToken)
{
SimpleAssignmentStatementInfo assignment = SyntaxInfo.SimpleAssignmentStatementInfo(expressionStatement);
if (!assignment.Success)
{
return(Empty);
}
ElseClauseSyntax elseClause = ifStatement.Else;
if (elseClause?.Statement?.IsKind(SyntaxKind.IfStatement) != false)
{
return(Empty);
}
SimpleAssignmentStatementInfo assignment1 = SyntaxInfo.SimpleAssignmentStatementInfo(ifStatement.SingleNonBlockStatementOrDefault());
if (!assignment1.Success)
{
return(Empty);
}
SimpleAssignmentStatementInfo assignment2 = SyntaxInfo.SimpleAssignmentStatementInfo(elseClause.SingleNonBlockStatementOrDefault());
if (!assignment2.Success)
{
return(Empty);
}
if (!AreEquivalent(assignment1.Left, assignment2.Left, assignment.Left))
{
return(Empty);
}
if (!options.CheckSpanDirectives(ifStatement.Parent, TextSpan.FromBounds(expressionStatement.SpanStart, ifStatement.Span.End)))
{
return(Empty);
}
if (IsNullLiteralConvertedToNullableOfT(assignment1.Right, semanticModel, cancellationToken) ||
IsNullLiteralConvertedToNullableOfT(assignment2.Right, semanticModel, cancellationToken))
{
return(Empty);
}
return(new AssignmentAndIfElseToAssignmentWithConditionalExpressionAnalysis(expressionStatement, assignment.Right, ifStatement, assignment1.Right, assignment2.Right, semanticModel).ToImmutableArray());
}
private static ImmutableArray <IfAnalysis> Analyze(
IfStatementSyntax ifStatement,
ReturnStatementSyntax returnStatement,
IfAnalysisOptions options,
SemanticModel semanticModel,
CancellationToken cancellationToken)
{
ExpressionSyntax condition = ifStatement.Condition?.WalkDownParentheses();
if (condition?.IsMissing != false)
{
return(Empty);
}
StatementSyntax statement = ifStatement.SingleNonBlockStatementOrDefault();
if (statement?.IsKind(SyntaxKind.ReturnStatement) != true)
{
return(Empty);
}
if (!options.CheckSpanDirectives(ifStatement, TextSpan.FromBounds(ifStatement.SpanStart, returnStatement.Span.End)))
{
return(Empty);
}
return(Analyze(
ifStatement,
condition,
((ReturnStatementSyntax)statement).Expression?.WalkDownParentheses(),
returnStatement.Expression?.WalkDownParentheses(),
options,
isYield: false,
semanticModel: semanticModel,
cancellationToken: cancellationToken));
}
public static ImmutableArray <IfAnalysis> Analyze(
IfStatementSyntax ifStatement,
IfAnalysisOptions options,
SemanticModel semanticModel,
CancellationToken cancellationToken = default(CancellationToken))
{
if (!ifStatement.IsTopmostIf())
{
return(Empty);
}
ExpressionSyntax condition = ifStatement.Condition?.WalkDownParentheses();
if (condition == null)
{
return(Empty);
}
ElseClauseSyntax elseClause = ifStatement.Else;
if (elseClause != null)
{
if (!options.CheckSpanDirectives(ifStatement))
{
return(Empty);
}
StatementSyntax statement1 = ifStatement.SingleNonBlockStatementOrDefault();
if (statement1 == null)
{
return(Empty);
}
SyntaxKind kind1 = statement1.Kind();
if (kind1.Is(
SyntaxKind.ExpressionStatement,
SyntaxKind.ReturnStatement,
SyntaxKind.YieldReturnStatement))
{
StatementSyntax statement2 = elseClause.SingleNonBlockStatementOrDefault();
if (statement2?.Kind() == kind1)
{
switch (kind1)
{
case SyntaxKind.ExpressionStatement:
{
return(Analyze(
ifStatement,
condition,
(ExpressionStatementSyntax)statement1,
(ExpressionStatementSyntax)statement2,
options,
semanticModel,
cancellationToken));
}
case SyntaxKind.ReturnStatement:
{
return(Analyze(
ifStatement,
condition,
((ReturnStatementSyntax)statement1).Expression?.WalkDownParentheses(),
((ReturnStatementSyntax)statement2).Expression?.WalkDownParentheses(),
options,
isYield: false,
semanticModel: semanticModel,
cancellationToken: cancellationToken));
}
case SyntaxKind.YieldReturnStatement:
{
return(Analyze(
ifStatement,
condition,
((YieldStatementSyntax)statement1).Expression?.WalkDownParentheses(),
((YieldStatementSyntax)statement2).Expression?.WalkDownParentheses(),
options,
isYield: true,
semanticModel: semanticModel,
cancellationToken: cancellationToken));
}
}
}
}
}
else if (ifStatement.NextStatement() is ReturnStatementSyntax returnStatement)
{
return(Analyze(ifStatement, returnStatement, options, semanticModel, cancellationToken));
}
return(Empty);
}
private static ImmutableArray <IfAnalysis> Analyze(
LocalDeclarationStatementSyntax localDeclarationStatement,
IfStatementSyntax ifStatement,
IfAnalysisOptions options,
SemanticModel semanticModel,
CancellationToken cancellationToken)
{
VariableDeclaratorSyntax declarator = localDeclarationStatement
.Declaration?
.Variables
.SingleOrDefault(shouldThrow: false);
if (declarator == null)
{
return(Empty);
}
ElseClauseSyntax elseClause = ifStatement.Else;
if (elseClause?.Statement?.IsKind(SyntaxKind.IfStatement) != false)
{
return(Empty);
}
SimpleAssignmentStatementInfo assignment1 = SyntaxInfo.SimpleAssignmentStatementInfo(ifStatement.SingleNonBlockStatementOrDefault());
if (!assignment1.Success)
{
return(Empty);
}
SimpleAssignmentStatementInfo assignment2 = SyntaxInfo.SimpleAssignmentStatementInfo(elseClause.SingleNonBlockStatementOrDefault());
if (!assignment2.Success)
{
return(Empty);
}
if (assignment1.Left.Kind() != SyntaxKind.IdentifierName)
{
return(Empty);
}
if (assignment2.Left.Kind() != SyntaxKind.IdentifierName)
{
return(Empty);
}
string identifier1 = ((IdentifierNameSyntax)assignment1.Left).Identifier.ValueText;
string identifier2 = ((IdentifierNameSyntax)assignment2.Left).Identifier.ValueText;
if (!string.Equals(identifier1, identifier2, StringComparison.Ordinal))
{
return(Empty);
}
if (!string.Equals(identifier1, declarator.Identifier.ValueText, StringComparison.Ordinal))
{
return(Empty);
}
if (!options.CheckSpanDirectives(ifStatement.Parent, TextSpan.FromBounds(localDeclarationStatement.SpanStart, ifStatement.Span.End)))
{
return(Empty);
}
if (IsNullLiteralConvertedToNullableOfT(assignment1.Right, semanticModel, cancellationToken) ||
IsNullLiteralConvertedToNullableOfT(assignment2.Right, semanticModel, cancellationToken))
{
return(Empty);
}
return(new LocalDeclarationAndIfElseToAssignmentWithConditionalExpressionAnalysis(localDeclarationStatement, ifStatement, assignment1.Right, assignment2.Right, semanticModel).ToImmutableArray());
}
