stride3d/stride · error · NotSupportedException

Unsupported literal type

Error message

Unsupported literal type: {literal.GetType()}

What it means

ComputeLiteralType's outer switch only recognizes BoolLiteral, IntegerLiteral, and FloatLiteral; any other Literal subtype throws NotSupportedException naming the literal's actual type. Unlike the blank NotImplementedException at CompileConstantLiteral line 312, this one includes the type name for diagnosis.

Solutions

1. Use only BoolLiteral/IntegerLiteral/FloatLiteral with this API
2. Add a switch arm in ComputeLiteralType mapping the new Literal subtype to its ScalarType (and matching arms in CompileConstantLiteral)
3. Convert the custom literal into a supported built-in literal before compiling

Example fix

// before
Literal lit = new HalfLiteral(2.0f); // custom subtype
ComputeLiteralType(lit); // throws
// after
Literal lit = new FloatLiteral(new(32, true, true), 2.0f, default);
ComputeLiteralType(lit); // ScalarType.Float

bool HasComputableScalarType(Literal lit) =>
    lit is BoolLiteral or IntegerLiteral or FloatLiteral;

static bool IsScalarLiteral(Literal l) => l is BoolLiteral or IntegerLiteral or FloatLiteral;

try
{
    var scalarType = SpirvContext.ComputeLiteralType(literal);
}
catch (NotSupportedException ex) when (ex.Message.Contains("Unsupported literal type"))
{
    // convert to a built-in scalar literal and retry
    var scalarType = SpirvContext.ComputeLiteralType(ToBuiltInLiteral(literal));
}

When it happens

Trigger: Passing a Literal that is not one of the three built-in kinds into ComputeLiteralType — typically via CompileConstantLiteral with a custom/new Literal subclass whose Type was null.

Common situations: Custom Literal implementations added by extension code; internal refactors adding a Literal kind without updating ComputeLiteralType; test harnesses constructing placeholder literals.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• Unsupported literal type
• Second parameter of geometry shader must be a…
• Semantic requested with type but last time with
• Unsupported float
• Unsupported integer suffix

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/8790b1385020ac23. Report an issue: GitHub.

Appendix: source

Thrown at sources/shaders/Stride.Shaders.Parsers/Spirv/Building/Context.Constants.cs:380

            {
                //{ Signed: true, Size: 8 } => ScalarType.SByte,
                //{ Signed: true, Size: 16 } => ScalarType.Short,
                { Signed: true, Size: 32 } => ScalarType.Int,
                { Signed: true, Size: 64 } => ScalarType.Int64,
                //{ Signed: false, Size: 8 } => ScalarType.UByte,
                //{ Signed: false, Size: 16 } => ScalarType.UShort,
                { Signed: false, Size: 32 } => ScalarType.UInt,
                { Signed: false, Size: 64 } => ScalarType.UInt64,
                _ => throw new NotImplementedException("Unsupported integer suffix")
            },
            FloatLiteral lit => lit.Suffix.Size switch
            {
                //16 => ScalarType.Half,
                32 => ScalarType.Float,
                64 => ScalarType.Double,
                _ => throw new NotImplementedException("Unsupported float")
            },
            _ => throw new NotSupportedException($"Unsupported literal type: {literal.GetType()}"),
        };
    }
}

View on GitHub (pinned to 96fad776d2)