public OperationDeconstructor(
Analyzer analyzer, IMethodSymbol method, ILocalSymbol?hashCodeVariable)
{
_analyzer = analyzer;
_method = method;
_hashCodeVariable = hashCodeVariable;
_hashedSymbols = ArrayBuilder <ISymbol> .GetInstance();
_accessesBase = false;
}
private static bool TryFindVariableDeclarator(
SemanticModel semanticModel,
IdentifierNameSyntax identifier,
[NotNullWhen(true)] out ILocalSymbol?localSymbol,
[NotNullWhen(true)] out VariableDeclaratorSyntax?declarator)
{
localSymbol = semanticModel.GetSymbolInfo(identifier).Symbol as ILocalSymbol;
declarator = localSymbol?.DeclaringSyntaxReferences.FirstOrDefault()?.GetSyntax() as VariableDeclaratorSyntax;
return(localSymbol != null && declarator != null);
}
private static bool TryGetTypeCheckParts(
SemanticModel semanticModel,
SyntaxNode operand,
[NotNullWhen(true)] out VariableDeclaratorSyntax?declarator,
[NotNullWhen(true)] out BinaryExpressionSyntax?asExpression,
[NotNullWhen(true)] out ILocalSymbol?localSymbol)
{
switch (operand.Kind())
{
case SyntaxKind.IdentifierName:
{
// var x = e as T;
// if (x != null) F(x);
var identifier = (IdentifierNameSyntax)operand;
if (!TryFindVariableDeclarator(semanticModel, identifier, out localSymbol, out declarator))
{
break;
}
var initializerValue = declarator.Initializer?.Value;
if (!initializerValue.IsKind(SyntaxKind.AsExpression, out asExpression))
{
break;
}
return(true);
}
case SyntaxKind.SimpleAssignmentExpression:
{
// T x;
// if ((x = e as T) != null) F(x);
var assignment = (AssignmentExpressionSyntax)operand;
if (!assignment.Right.IsKind(SyntaxKind.AsExpression, out asExpression) ||
!assignment.Left.IsKind(SyntaxKind.IdentifierName, out IdentifierNameSyntax? identifier))
{
break;
}
if (!TryFindVariableDeclarator(semanticModel, identifier, out localSymbol, out declarator))
{
break;
}
return(true);
}
}
declarator = null;
asExpression = null;
localSymbol = null;
return(false);
}
/// <summary> Determines equality by name and containing symbol. </summary>
/// <param name="x">The first instance.</param>
/// <param name="y">The other instance.</param>
/// <returns>True if the instances are found equal.</returns>
public static bool Equal(ILocalSymbol?x, ILocalSymbol?y)
{
if (ReferenceEquals(x, y))
{
return(true);
}
if (x is null ||
y is null)
{
return(false);
}
return(x.MetadataName == y.MetadataName &&
SymbolComparer.Equal(x.ContainingSymbol, y.ContainingSymbol));
}
public LocalDefinition(
ILocalSymbol?symbolOpt,
string?nameOpt,
Cci.ITypeReference type,
int slot,
SynthesizedLocalKind synthesizedKind,
LocalDebugId id,
LocalVariableAttributes pdbAttributes,
LocalSlotConstraints constraints,
ImmutableArray <bool> dynamicTransformFlags,
ImmutableArray <string> tupleElementNames)
{
_symbolOpt = symbolOpt;
_nameOpt = nameOpt;
_type = type;
_slot = slot;
_slotInfo = new LocalSlotDebugInfo(synthesizedKind, id);
_pdbAttributes = pdbAttributes;
_dynamicTransformFlags = dynamicTransformFlags.NullToEmpty();
_tupleElementNames = tupleElementNames.NullToEmpty();
_constraints = constraints;
}
private bool TryFindMatchingLocalDeclarationImmediatelyAbove(
IConditionalOperation ifOperation,
ISimpleAssignmentOperation?trueAssignment,
ISimpleAssignmentOperation?falseAssignment,
[NotNullWhen(true)] out IVariableDeclarationGroupOperation?localDeclaration,
[NotNullWhen(true)] out IVariableDeclaratorOperation?declarator)
{
localDeclaration = null;
declarator = null;
ILocalSymbol?local = null;
if (trueAssignment != null)
{
if (!(trueAssignment.Target is ILocalReferenceOperation trueLocal))
{
return(false);
}
local = trueLocal.Local;
}
if (falseAssignment != null)
{
if (!(falseAssignment.Target is ILocalReferenceOperation falseLocal))
{
return(false);
}
// See if both assignments are to the same local.
if (local != null && !Equals(local, falseLocal.Local))
{
return(false);
}
local = falseLocal.Local;
}
// We weren't assigning to a local.
if (local == null)
{
return(false);
}
// If so, see if that local was declared immediately above the if-statement.
if (!(ifOperation.Parent is IBlockOperation parentBlock))
{
return(false);
}
var ifIndex = parentBlock.Operations.IndexOf(ifOperation);
if (ifIndex <= 0)
{
return(false);
}
localDeclaration = parentBlock.Operations[ifIndex - 1] as IVariableDeclarationGroupOperation;
if (localDeclaration == null)
{
return(false);
}
if (localDeclaration.IsImplicit)
{
return(false);
}
if (localDeclaration.Declarations.Length != 1)
{
return(false);
}
var declaration = localDeclaration.Declarations[0];
var declarators = declaration.Declarators;
if (declarators.Length != 1)
{
return(false);
}
declarator = declarators[0];
var variable = declarator.Symbol;
if (!Equals(variable, local))
{
// wasn't a declaration of the local we're assigning to.
return(false);
}
var variableInitializer = declarator.Initializer ?? declaration.Initializer;
if (variableInitializer?.Value != null)
{
var unwrapped = UnwrapImplicitConversion(variableInitializer.Value);
// the variable has to either not have an initializer, or it needs to be basic
// literal/default expression.
if (!(unwrapped is ILiteralOperation) &&
!(unwrapped is IDefaultValueOperation))
{
return(false);
}
}
// If the variable is referenced in the condition of the 'if' block, we can't merge the
// declaration and assignments.
return(!ReferencesLocalVariable(ifOperation.Condition, variable));
}
internal static LocalSymbol? GetSymbol(this ILocalSymbol? symbol)
{
return symbol.GetSymbol<LocalSymbol>();
}
#pragma warning restore CS1591,CA1707,IDE1006,SA1313,SA1600
//// ReSharper restore UnusedParameter.Global
/// <inheritdoc />
bool IEqualityComparer <ILocalSymbol> .Equals(ILocalSymbol?x, ILocalSymbol?y) => Equal(x, y);
public static bool Equals(ILocalSymbol?x, ILocalSymbol?y) => Equal(x, y);
/// <summary>
/// Try getting the <see cref="ILocalSymbol"/> for the node.
/// Gets the semantic model for the tree if the node is not in the tree corresponding to <paramref name="semanticModel"/>.
/// </summary>
/// <param name="semanticModel">The <see cref="SemanticModel"/>.</param>
/// <param name="node">The <see cref="SingleVariableDesignationSyntax"/>.</param>
/// <param name="cancellationToken">The <see cref="CancellationToken"/>.</param>
/// <param name="symbol">The symbol if found.</param>
/// <returns>True if a symbol was found.</returns>
public static bool TryGetSymbol(this SemanticModel semanticModel, SingleVariableDesignationSyntax node, CancellationToken cancellationToken, [NotNullWhen(true)] out ILocalSymbol?symbol)
{
if (semanticModel is null)
{
throw new ArgumentNullException(nameof(semanticModel));
}
if (node is null)
{
throw new ArgumentNullException(nameof(node));
}
symbol = GetDeclaredSymbolSafe(semanticModel, node, cancellationToken);
return(symbol != null);
}
