stride3d/stride · critical · Exception

Constant has no result id

Error message

Constant has no result id

What it means

After AddConstant emits an OpConstant instruction into the SPIR-V buffer, it reads back the instruction's result-id slot (index+1) to return the newly allocated id. If InstructionInfo.GetInfo(data).GetResultIndex fails, the emitted instruction has no result-id operand — which should be impossible for a valid OpConstant — so the library throws 'Constant has no result id'. This indicates the instruction stream or the SPIR-V specification opcode metadata table is inconsistent.

Solutions

1. Regenerate/verify the SPIR-V InstructionInfo metadata so OpConstant declares a result-id operand.
2. Confirm the Buffer.AddData return value is a complete, well-formed instruction (opcode + word count + operands).
3. Update the Stride.Shaders.Parsers package/spec files to a matching version.

if (!InstructionInfo.GetInfo(data).GetResultIndex(out _)) throw new InvalidOperationException("InstructionInfo metadata does not define a result id for the emitted constant");

try { return context.AddConstant(v); } catch (Exception ex) when (ex.Message == "Constant has no result id") { /* regenerate spec metadata / report toolchain bug */ }

When it happens

Trigger: Calling AddConstant when the emitted data's opcode does not resolve to an instruction with a result-id operand — typically because the SPIR-V specification metadata (InstructionInfo) is missing or stale for OpConstant, or the buffer returned corrupted/truncated data.

Common situations: Version skew between the SPIR-V specification generator and the parser assembly; custom builds where InstructionInfo tables were regenerated from an incomplete spec; memory corruption of the emitted OpDataIndex.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• Cannot find instruction for id {constantId}
• Cannot find constant instruction for id
• Can't process constant {i.Data.IdResult}
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• Given PropertyKey doesn't have accessor metadata.

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/9cb3f71579932566. Report an issue: GitHub.

Appendix: source

Thrown at sources/shaders/Stride.Shaders.Parsers/Spirv/Building/Context.Constants.cs:32

    public Dictionary<(SymbolType Type, object Value), SpirvValue> LiteralConstants { get; } = [];

    public int AddConstant<TScalar>(TScalar value)
        where TScalar : INumber<TScalar>
    {
        var data = value switch
        {
            uint v => Buffer.AddData(new OpConstant<uint>(GetOrRegister(ScalarType.UInt), Bound++, v)),
            int v => Buffer.AddData(new OpConstant<int>(GetOrRegister(ScalarType.Int), Bound++, v)),
            ulong v => Buffer.AddData(new OpConstant<ulong>(GetOrRegister(ScalarType.UInt64), Bound++, v)),
            long v => Buffer.AddData(new OpConstant<long>(GetOrRegister(ScalarType.Int64), Bound++, v)),
            Half v => Buffer.AddData(new OpConstant<Half>(GetOrRegister(ScalarType.Half), Bound++, v)),
            float v => Buffer.AddData(new OpConstant<float>(GetOrRegister(ScalarType.Float), Bound++, v)),
            double v => Buffer.AddData(new OpConstant<double>(GetOrRegister(ScalarType.Double), Bound++, v)),
            _ => throw new NotImplementedException()
        };
        if (InstructionInfo.GetInfo(data).GetResultIndex(out var index))
            return data.Memory.Span[index + 1];
        throw new Exception("Constant has no result id");
    }

    public object GetConstantValue(int constantId)
    {
        if (Buffer.TryGetInstructionById(constantId, out var constant))
        {
            return ResolveConstantValue(constant);
        }

        throw new Exception("Cannot find constant instruction for id " + constantId);
    }

    public bool TryGetConstantValue(int constantId, [MaybeNullWhen(false)] out object value, out int typeId)
    {
        if (Buffer.TryGetInstructionById(constantId, out var constant))
        {
            return TryGetConstantValue(constant, out value, out typeId);
        }

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