Source/WebGPU/WGSL/WGSLShaderModule.cpp

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#include "config.h"
#include "WGSLShaderModule.h"

#include "AST.h"
#include "ConstantFunctions.h"
#include "WGSL.h"
#include <wtf/TZoneMallocInlines.h>

namespace WGSL {

WTF_MAKE_TZONE_ALLOCATED_IMPL(ShaderModule);

Result<ConstantValue> ShaderModule::ensureOverrideValue(const AST::Expression& expression, const HashMap<String, ConstantValue>& overrideValues) const
{
    auto maybeValue = evaluate(*this, expression, overrideValues);
    if (!maybeValue)
        return makeUnexpected(Error("Failed to evaluate override value"_s, expression.span()));
    return { *maybeValue };
}

std::optional<Error> ShaderModule::validateOverrides(const PrepareResult& prepareResult, HashMap<String, ConstantValue>& overrideValues)
{
    for (auto* variable : m_overrides) {
        String name = variable->id().has_value() ? String::number(*variable->id()) : variable->originalName();
        auto userDefinedValue = overrideValues.find(name);
        if (userDefinedValue != overrideValues.end()) {
            auto value = userDefinedValue->value;
            overrideValues.remove(name);
            overrideValues.add(variable->name(), value);
            continue;
        }

        bool isUsed = false;
        for (const auto& [_, entryPoint] : prepareResult.entryPoints) {
            if (entryPoint.specializationConstants.contains(name)) {
                isUsed = true;
                break;
            }
        }

        if (!isUsed)
            continue;

        auto* initializer = variable->maybeInitializer();
        if (!initializer) {
            if (isUsed)
                return { Error(makeString("override "_s, variable->originalName(), " is used in shader but not provided"_s), variable->span()) };
            continue;
        }

        auto maybeValue = ensureOverrideValue(*initializer, overrideValues);
        if (!maybeValue)
            return maybeValue.error();

        overrideValues.add(variable->name(), *maybeValue);
    }

    for (const auto& validator : m_overrideValidations) {
        if (auto maybeError = validator(overrideValues))
            return maybeError;
    }

    return std::nullopt;
}

void ShaderModule::initializeOverloads()
{
    // This file contains the overloads generated from `TypeDeclarations.rb`
    #include "TypeOverloads.h" // NOLINT
}

const OverloadedDeclaration* ShaderModule::lookupOverload(const String& name) const
{
    auto it = m_overloadedOperations.find(name);
    if (it == m_overloadedOperations.end())
        return nullptr;
    return &it->value;
}

} // namespace WGSL