private ExpressionSyntax AddExplicitConversion(Microsoft.CodeAnalysis.VisualBasic.Syntax.ExpressionSyntax vbNode, ExpressionSyntax csNode,
ITypeSymbol vbConvertedType, TypeConversionKind conversionKind, bool addParenthesisIfNeeded)
{
switch (conversionKind)
{
case TypeConversionKind.Unknown:
case TypeConversionKind.Identity:
return(addParenthesisIfNeeded ? VbSyntaxNodeExtensions.ParenthesizeIfPrecedenceCouldChange(vbNode, csNode) : csNode);
case TypeConversionKind.Implicit:
return(ValidSyntaxFactory.CastExpression(_semanticModel.GetCsTypeSyntax(vbConvertedType, vbNode), csNode));
case TypeConversionKind.Explicit:
return(AddExplicitConvertTo(vbNode, csNode, vbConvertedType));
default:
throw new ArgumentOutOfRangeException();
}
}
private ExpressionSyntax AddTypeConversion(VBSyntax.ExpressionSyntax vbNode, ExpressionSyntax csNode, TypeConversionKind conversionKind, bool addParenthesisIfNeeded, ITypeSymbol vbType, ITypeSymbol vbConvertedType)
{
switch (conversionKind)
{
case TypeConversionKind.EnumConversionThenCast:
var underlyingType = ((INamedTypeSymbol)vbConvertedType).EnumUnderlyingType;
csNode = AddTypeConversion(vbNode, csNode, TypeConversionKind.Conversion, addParenthesisIfNeeded, vbType, underlyingType);
return(AddTypeConversion(vbNode, csNode, TypeConversionKind.NonDestructiveCast, addParenthesisIfNeeded, underlyingType, vbConvertedType));
case TypeConversionKind.EnumCastThenConversion:
var enumUnderlyingType = ((INamedTypeSymbol)vbType).EnumUnderlyingType;
csNode = AddTypeConversion(vbNode, csNode, TypeConversionKind.NonDestructiveCast, addParenthesisIfNeeded, vbType, enumUnderlyingType);
return(AddTypeConversion(vbNode, csNode, TypeConversionKind.Conversion, addParenthesisIfNeeded, enumUnderlyingType, vbConvertedType));
case TypeConversionKind.Unknown:
case TypeConversionKind.Identity:
return(addParenthesisIfNeeded ? vbNode.ParenthesizeIfPrecedenceCouldChange(csNode) : csNode);
case TypeConversionKind.DestructiveCast:
case TypeConversionKind.NonDestructiveCast:
return(CreateCast(csNode, vbConvertedType));
case TypeConversionKind.Conversion:
return(AddExplicitConvertTo(vbNode, csNode, vbType, vbConvertedType));;
case TypeConversionKind.NullableBool:
return(SyntaxFactory.BinaryExpression(SyntaxKind.EqualsExpression, csNode,
LiteralConversions.GetLiteralExpression(true)));
case TypeConversionKind.StringToCharArray:
var memberAccessExpressionSyntax = SyntaxFactory.MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression, csNode, SyntaxFactory.IdentifierName(nameof(string.ToCharArray)));
return(SyntaxFactory.InvocationExpression(memberAccessExpressionSyntax,
SyntaxFactory.ArgumentList()));
case TypeConversionKind.DelegateConstructor:
return(SyntaxFactory.ObjectCreationExpression(GetCommonDelegateTypeOrNull(vbNode, vbConvertedType)).WithArgumentList(new[] { csNode }.CreateCsArgList()));
default:
throw new ArgumentOutOfRangeException();
}
}
public (ExpressionSyntax Expr, bool IsConst) AddExplicitConversion(VBSyntax.ExpressionSyntax vbNode, ExpressionSyntax csNode, TypeConversionKind conversionKind, bool addParenthesisIfNeeded = false, bool requiresConst = false, ITypeSymbol forceSourceType = null, ITypeSymbol forceTargetType = null)
{
var(vbType, vbConvertedType) = GetTypeInfo(vbNode, forceSourceType, forceTargetType);
bool resultConst = false;
if (requiresConst)
{
var(constExpression, isCorrectType) = _expressionEvaluator.GetConstantOrNull(vbNode, vbConvertedType, conversionKind, csNode);
if (isCorrectType)
{
return(constExpression, true);
}
if (constExpression != null)
{
csNode = constExpression ?? csNode;
resultConst = true;
}
}
var typeConvertedResult = AddTypeConversion(vbNode, csNode, conversionKind, addParenthesisIfNeeded, vbType, vbConvertedType);
return(typeConvertedResult, resultConst);
}
public ExpressionSyntax AddExplicitConversion(Microsoft.CodeAnalysis.VisualBasic.Syntax.ExpressionSyntax vbNode, ExpressionSyntax csNode, TypeConversionKind conversionKind, bool addParenthesisIfNeeded = false, ITypeSymbol forceTargetType = null)
{
var vbConvertedType = forceTargetType ?? ModelExtensions.GetTypeInfo(_semanticModel, vbNode).ConvertedType;
switch (conversionKind)
{
case TypeConversionKind.Unknown:
case TypeConversionKind.Identity:
return(addParenthesisIfNeeded ? VbSyntaxNodeExtensions.ParenthesizeIfPrecedenceCouldChange(vbNode, csNode) : csNode);
case TypeConversionKind.DestructiveCast:
case TypeConversionKind.NonDestructiveCast:
return(CreateCast(csNode, vbConvertedType));
case TypeConversionKind.Conversion:
return(AddExplicitConvertTo(vbNode, csNode, vbConvertedType));
case TypeConversionKind.ConstConversion:
return(ConstantFold(vbNode, vbConvertedType));
case TypeConversionKind.NullableBool:
return(SyntaxFactory.BinaryExpression(SyntaxKind.EqualsExpression, csNode,
LiteralConversions.GetLiteralExpression(true)));
case TypeConversionKind.StringToCharArray:
var memberAccessExpressionSyntax = SyntaxFactory.MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression, csNode, SyntaxFactory.IdentifierName(nameof(string.ToCharArray)));
return(SyntaxFactory.InvocationExpression(memberAccessExpressionSyntax,
SyntaxFactory.ArgumentList()));
default:
throw new ArgumentOutOfRangeException();
}
}
private bool TryAnalyzeCsConversion(Microsoft.CodeAnalysis.VisualBasic.Syntax.ExpressionSyntax vbNode, ITypeSymbol csType,
ITypeSymbol csConvertedType, Conversion vbConversion, ITypeSymbol vbConvertedType, ITypeSymbol vbType,
VisualBasicCompilation vbCompilation, bool isConst, out TypeConversionKind typeConversionKind)
{
var csConversion = _csCompilation.ClassifyConversion(csType, csConvertedType);
bool isConvertToString =
(vbConversion.IsString || vbConversion.IsReference && vbConversion.IsNarrowing) && vbConvertedType.SpecialType == SpecialType.System_String;
bool isArithmetic = vbNode.IsKind(Microsoft.CodeAnalysis.VisualBasic.SyntaxKind.AddExpression,
Microsoft.CodeAnalysis.VisualBasic.SyntaxKind.SubtractExpression,
Microsoft.CodeAnalysis.VisualBasic.SyntaxKind.MultiplyExpression,
Microsoft.CodeAnalysis.VisualBasic.SyntaxKind.DivideExpression,
Microsoft.CodeAnalysis.VisualBasic.SyntaxKind.IntegerDivideExpression);
if (!csConversion.Exists || csConversion.IsUnboxing)
{
if (ConvertStringToCharLiteral(vbNode, vbConvertedType, out _))
{
typeConversionKind =
TypeConversionKind.Identity; // Already handled elsewhere by other usage of method
return(true);
}
if (vbType.SpecialType == SpecialType.System_String && vbConvertedType.IsArrayOf(SpecialType.System_Char))
{
typeConversionKind = TypeConversionKind.StringToCharArray;
return(true);
}
if (isConvertToString || vbConversion.IsNarrowing)
{
typeConversionKind = isConst ? TypeConversionKind.ConstConversion : TypeConversionKind.Conversion;
return(true);
}
}
else if (vbConversion.IsWidening && vbConversion.IsNumeric && csConversion.IsImplicit &&
csConversion.IsNumeric)
{
// Safe overapproximation: A cast is really only needed to help resolve the overload for the operator/method used.
// e.g. When VB "&" changes to C# "+", there are lots more overloads available that implicit casts could match.
// e.g. sbyte * ulong uses the decimal * operator in VB. In C# it's ambiguous - see ExpressionTests.vb "TestMul".
typeConversionKind = TypeConversionKind.NonDestructiveCast;
return(true);
}
else if (csConversion.IsExplicit && csConversion.IsEnumeration)
{
typeConversionKind = TypeConversionKind.NonDestructiveCast;
return(true);
}
else if (isArithmetic)
{
var arithmeticConversion =
vbCompilation.ClassifyConversion(vbConvertedType,
vbCompilation.GetTypeByMetadataName("System.Int32"));
if (arithmeticConversion.IsWidening && !arithmeticConversion.IsIdentity)
{
typeConversionKind = isConst ? TypeConversionKind.ConstConversion : TypeConversionKind.Conversion;
return(true);
}
}
else if (csConversion.IsExplicit && csConversion.IsNumeric && vbConversion.IsNarrowing && isConst)
{
typeConversionKind = IsImplicitConstantConversion(vbNode) ? TypeConversionKind.Identity : TypeConversionKind.NonDestructiveCast;
return(true);
}
else if (csConversion.IsExplicit && vbConversion.IsNumeric && vbType.TypeKind != TypeKind.Enum)
{
typeConversionKind = IsImplicitConstantConversion(vbNode) ? TypeConversionKind.Identity :
isConst ? TypeConversionKind.ConstConversion : TypeConversionKind.Conversion;
return(true);
}
else if (csConversion.IsExplicit && vbConversion.IsIdentity && csConversion.IsNumeric && vbType.TypeKind != TypeKind.Enum)
{
typeConversionKind = isConst ? TypeConversionKind.ConstConversion : TypeConversionKind.Conversion;
return(true);
}
else if (isConvertToString && vbType.SpecialType == SpecialType.System_Object)
{
typeConversionKind = isConst ? TypeConversionKind.ConstConversion : TypeConversionKind.Conversion;
return(true);
}
else if (csConversion.IsNullable && csConvertedType.SpecialType == SpecialType.System_Boolean)
{
typeConversionKind = TypeConversionKind.NullableBool;
return(true);
}
else if (csConversion.IsExplicit)
{
typeConversionKind = TypeConversionKind.DestructiveCast;
return(true);
}
typeConversionKind = csConversion.IsIdentity ? TypeConversionKind.Identity : TypeConversionKind.Unknown;
return(false);
}
public ExpressionSyntax AddExplicitConversion(Microsoft.CodeAnalysis.VisualBasic.Syntax.ExpressionSyntax vbNode, ExpressionSyntax csNode, TypeConversionKind conversionKind, bool addParenthesisIfNeeded = false)
{
var vbConvertedType = ModelExtensions.GetTypeInfo(_semanticModel, vbNode).ConvertedType;
switch (conversionKind)
{
case TypeConversionKind.Unknown:
case TypeConversionKind.Identity:
return(addParenthesisIfNeeded ? VbSyntaxNodeExtensions.ParenthesizeIfPrecedenceCouldChange(vbNode, csNode) : csNode);
case TypeConversionKind.DestructiveCast:
case TypeConversionKind.NonDestructiveCast:
return(CreateCast(csNode, vbConvertedType));
case TypeConversionKind.Conversion:
return(AddExplicitConvertTo(vbNode, csNode, vbConvertedType));
default:
throw new ArgumentOutOfRangeException();
}
}
private ExpressionSyntax AddTypeConversion(VBSyntax.ExpressionSyntax vbNode, ExpressionSyntax csNode, TypeConversionKind conversionKind, bool addParenthesisIfNeeded, ITypeSymbol vbType, ITypeSymbol vbConvertedType)
{
switch (conversionKind)
{
case TypeConversionKind.Unknown:
case TypeConversionKind.Identity:
return(addParenthesisIfNeeded ? VbSyntaxNodeExtensions.ParenthesizeIfPrecedenceCouldChange(vbNode, csNode) : csNode);
case TypeConversionKind.DestructiveCast:
case TypeConversionKind.NonDestructiveCast:
return(CreateCast(csNode, vbConvertedType));
case TypeConversionKind.Conversion:
return(AddExplicitConvertTo(vbNode, csNode, vbType, vbConvertedType));;
case TypeConversionKind.NullableBool:
return(SyntaxFactory.BinaryExpression(SyntaxKind.EqualsExpression, csNode,
LiteralConversions.GetLiteralExpression(true)));
case TypeConversionKind.StringToCharArray:
var memberAccessExpressionSyntax = SyntaxFactory.MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression, csNode, SyntaxFactory.IdentifierName(nameof(string.ToCharArray)));
return(SyntaxFactory.InvocationExpression(memberAccessExpressionSyntax,
SyntaxFactory.ArgumentList()));
default:
throw new ArgumentOutOfRangeException();
}
}
public (ExpressionSyntax Expr, bool IsConst) AddExplicitConversion(Microsoft.CodeAnalysis.VisualBasic.Syntax.ExpressionSyntax vbNode, ExpressionSyntax csNode, TypeConversionKind conversionKind, bool addParenthesisIfNeeded = false, bool requiresConst = false, ITypeSymbol forceSourceType = null, ITypeSymbol forceTargetType = null)
{
var typeInfo = ModelExtensions.GetTypeInfo(_semanticModel, vbNode);
var vbType = forceSourceType ?? typeInfo.Type;
var vbConvertedType = forceTargetType ?? typeInfo.ConvertedType;
bool resultConst = false;
if (requiresConst)
{
var(constExpression, isCorrectType) = _expressionEvaluator.GetConstantOrNull(vbNode, vbConvertedType, conversionKind, csNode);
if (isCorrectType)
{
return(constExpression, true);
}
if (constExpression != null)
{
csNode = constExpression ?? csNode;
resultConst = true;
}
}
var typeConvertedResult = AddTypeConversion(vbNode, csNode, conversionKind, addParenthesisIfNeeded, vbType, vbConvertedType);
return(typeConvertedResult, resultConst);
}
private ExpressionSyntax AddExplicitConversion(Microsoft.CodeAnalysis.VisualBasic.Syntax.ExpressionSyntax vbNode, ExpressionSyntax csNode, TypeConversionKind conversionKind, bool addParenthesisIfNeeded)
{
var vbConvertedType = _semanticModel.GetTypeInfo(vbNode).ConvertedType;
switch (conversionKind)
{
case TypeConversionKind.Unknown:
case TypeConversionKind.Identity:
return(addParenthesisIfNeeded ? VbSyntaxNodeExtensions.ParenthesizeIfPrecedenceCouldChange(vbNode, csNode) : csNode);
case TypeConversionKind.DestructiveCast:
case TypeConversionKind.NonDestructiveCast:
var typeName = (TypeSyntax)_csSyntaxGenerator.TypeExpression(vbConvertedType);
if (csNode is CastExpressionSyntax cast && cast.Type.IsEquivalentTo(typeName))
{
return(csNode);
}
return(ValidSyntaxFactory.CastExpression(typeName, csNode));
case TypeConversionKind.Conversion:
return(AddExplicitConvertTo(vbNode, csNode, vbConvertedType));
default:
throw new ArgumentOutOfRangeException();
}
}
