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#ifndef SRC_TINT_LANG_CORE_IR_FUNCTION_PARAM_H_
#define SRC_TINT_LANG_CORE_IR_FUNCTION_PARAM_H_

#include <utility>

#include "src/tint/api/common/binding_point.h"
#include "src/tint/lang/core/builtin_value.h"
#include "src/tint/lang/core/ir/location.h"
#include "src/tint/lang/core/ir/value.h"
#include "src/tint/utils/containers/vector.h"
#include "src/tint/utils/ice/ice.h"
#include "src/tint/utils/rtti/castable.h"

// Forward declarations
namespace tint::core::ir {
class Function;
}  // namespace tint::core::ir

namespace tint::core::ir {

/// A function parameter in the IR.
class FunctionParam : public Castable<FunctionParam, Value> {
  public:
    /// Constructor
    /// @param type the type of the var
    explicit FunctionParam(const core::type::Type* type);
    ~FunctionParam() override;

    /// Sets the function that this parameter belongs to.
    /// @param func the function
    void SetFunction(ir::Function* func) { func_ = func; }

    /// @returns the function that this parameter belongs to, or nullptr
    ir::Function* Function() { return func_; }

    /// @returns the function that this parameter belongs to, or nullptr
    const ir::Function* Function() const { return func_; }

    /// Sets the index of the parameter in the function's parameter list
    /// @param index the index
    void SetIndex(uint32_t index) { index_ = index; }

    /// @returns the index of the parameter in the function's parameter list
    uint32_t Index() const { return index_; }

    /// @returns the type of the var
    const core::type::Type* Type() const override { return type_; }

    /// Sets the type of the parameter to @p type
    /// @param type the new type of the parameter
    void SetType(const core::type::Type* type) { type_ = type; }

    /// @copydoc Value::Clone()
    FunctionParam* Clone(CloneContext& ctx) override;

    /// Sets the builtin information. Note, it is currently an error if the builtin is already set.
    /// @param val the builtin to set
    void SetBuiltin(core::BuiltinValue val) {
        TINT_ASSERT(!builtin_.has_value());
        builtin_ = val;
    }
    /// @returns the builtin set for the parameter
    std::optional<core::BuiltinValue> Builtin() const { return builtin_; }

    /// Clears the builtin attribute.
    void ClearBuiltin() { builtin_ = {}; }

    /// Sets the parameter as invariant
    /// @param val the value to set for invariant
    void SetInvariant(bool val) { invariant_ = val; }

    /// @returns true if parameter is invariant
    bool Invariant() const { return invariant_; }

    /// Sets the location
    /// @param location the location
    void SetLocation(ir::Location location) { location_ = std::move(location); }

    /// Sets the location
    /// @param loc the location value
    /// @param interpolation if the location interpolation settings
    void SetLocation(uint32_t loc, std::optional<core::Interpolation> interpolation) {
        location_ = {loc, interpolation};
    }

    /// @returns the location if `Attributes` contains `kLocation`
    std::optional<ir::Location> Location() const { return location_; }

    /// Clears the location attribute.
    void ClearLocation() { location_ = {}; }

    /// Sets the binding point
    /// @param group the group
    /// @param binding the binding
    void SetBindingPoint(uint32_t group, uint32_t binding) { binding_point_ = {group, binding}; }

    /// Sets the binding point
    /// @param binding_point the binding point
    void SetBindingPoint(std::optional<struct BindingPoint> binding_point) {
        binding_point_ = binding_point;
    }

    /// @returns the binding points if `Attributes` contains `kBindingPoint`
    std::optional<struct BindingPoint> BindingPoint() const { return binding_point_; }

  private:
    ir::Function* func_ = nullptr;
    uint32_t index_ = 0xffffffff;
    const core::type::Type* type_ = nullptr;
    std::optional<core::BuiltinValue> builtin_;
    std::optional<struct Location> location_;
    std::optional<struct BindingPoint> binding_point_;
    bool invariant_ = false;
};

}  // namespace tint::core::ir

#endif  // SRC_TINT_LANG_CORE_IR_FUNCTION_PARAM_H_