public override Conversion GetStackAllocConversion(BoundStackAllocArrayCreation sourceExpression, TypeSymbol destination, ref HashSet <DiagnosticInfo> useSiteDiagnostics)
{
if (sourceExpression.Syntax.IsVariableDeclarationInitialization())
{
Debug.Assert((object)sourceExpression.Type == null);
Debug.Assert((object)sourceExpression.ElementType != null);
var sourceAsPointer = new PointerTypeSymbol(TypeSymbolWithAnnotations.Create(sourceExpression.ElementType));
var pointerConversion = ClassifyImplicitConversionFromType(sourceAsPointer, destination, ref useSiteDiagnostics);
if (pointerConversion.IsValid)
{
return(Conversion.MakeStackAllocToPointerType(pointerConversion));
}
else
{
var spanType = _binder.GetWellKnownType(WellKnownType.core_Span_T, ref useSiteDiagnostics);
if (spanType.TypeKind == TypeKind.Struct && spanType.IsRefLikeType)
{
var spanType_T = spanType.Construct(sourceExpression.ElementType);
var spanConversion = ClassifyImplicitConversionFromType(spanType_T, destination, ref useSiteDiagnostics);
if (spanConversion.Exists)
{
return(Conversion.MakeStackAllocToSpanType(spanConversion));
}
}
}
}
return(Conversion.NoConversion);
}
public override BoundNode VisitStackAllocArrayCreation(BoundStackAllocArrayCreation stackAllocNode)
{
var rewrittenCount = VisitExpression(stackAllocNode.Count);
var type = stackAllocNode.Type;
if (rewrittenCount.ConstantValue?.Int32Value == 0)
{
// either default(span) or nullptr
return(_factory.Default(type));
}
var elementType = stackAllocNode.ElementType;
var initializerOpt = stackAllocNode.InitializerOpt;
if (initializerOpt != null)
{
initializerOpt = initializerOpt.Update(VisitList(initializerOpt.Initializers));
}
if (type.IsPointerType())
{
var stackSize = RewriteStackAllocCountToSize(rewrittenCount, elementType);
return(new BoundConvertedStackAllocExpression(stackAllocNode.Syntax, elementType, stackSize, initializerOpt, stackAllocNode.Type));
}
else if (TypeSymbol.Equals(type.OriginalDefinition, _compilation.GetWellKnownType(WellKnownType.core_Span_T), TypeCompareKind.ConsiderEverything2))
{
var spanType = (NamedTypeSymbol)stackAllocNode.Type;
var sideEffects = ArrayBuilder <BoundExpression> .GetInstance();
var locals = ArrayBuilder <LocalSymbol> .GetInstance();
var countTemp = CaptureExpressionInTempIfNeeded(rewrittenCount, sideEffects, locals);
var stackSize = RewriteStackAllocCountToSize(countTemp, elementType);
stackAllocNode = new BoundConvertedStackAllocExpression(stackAllocNode.Syntax, elementType, stackSize, initializerOpt, spanType);
BoundExpression constructorCall;
if (TryGetWellKnownTypeMember(stackAllocNode.Syntax, WellKnownMember.System_Span_T__ctor, out MethodSymbol spanConstructor))
{
constructorCall = _factory.New((MethodSymbol)spanConstructor.SymbolAsMember(spanType), stackAllocNode, countTemp);
}
else
{
constructorCall = new BoundBadExpression(
syntax: stackAllocNode.Syntax,
resultKind: LookupResultKind.NotInvocable,
symbols: ImmutableArray <Symbol> .Empty,
childBoundNodes: ImmutableArray <BoundExpression> .Empty,
type: ErrorTypeSymbol.UnknownResultType);
}
return(new BoundSequence(
syntax: stackAllocNode.Syntax,
locals: locals.ToImmutableAndFree(),
sideEffects: sideEffects.ToImmutableAndFree(),
value: constructorCall,
type: spanType));
}
else
{
throw ExceptionUtilities.UnexpectedValue(type);
}
}
public override Conversion GetStackAllocConversion(BoundStackAllocArrayCreation sourceExpression, TypeSymbol destination, ref HashSet <DiagnosticInfo> useSiteDiagnostics)
{
// Conversions involving stackalloc expressions require a Binder.
throw ExceptionUtilities.Unreachable;
}
