ir-traversal-internal.h

/*
 * SPDX-FileCopyrightText: 2024 Intel Corporation.
 * Copyright 2024-present Intel Corporation.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef IR_IR_TRAVERSAL_INTERNAL_H_
#define IR_IR_TRAVERSAL_INTERNAL_H_
 
#include "lib/exceptions.h"
#include "lib/rtti_utils.h"
 
#ifndef IR_IR_TRAVERSAL_INTERNAL_ENABLE
#error "This file must not be used directly"
#endif
 
namespace P4::IR::Traversal::Detail {

struct Traverse {
    template <typename Obj, typename T>
    static const Obj *modify(const Obj *, Assign<const T *> asgn) {
        static_assert(!std::is_const_v<Obj>, "Cannot modify constant object");
        return asgn.value;
    }
 
    template <typename Obj, typename T>
    static const Obj *modify(Obj *, Assign<const T *> asgn) {
        static_assert(!std::is_const_v<Obj>, "Cannot modify constant object");
        return asgn.value;
    }
 
    template <typename Obj, typename T>
    static Obj *modify(Obj *obj, Assign<T> &&asgn) {
        static_assert(!std::is_const_v<Obj>, "Cannot modify constant object");
        *obj = std::move(asgn.value);
        return obj;
    }
 
    template <typename Obj, typename T>
    static Obj *modify(Obj *obj, const Assign<T> &asgn) {
        static_assert(!std::is_const_v<Obj>, "Cannot modify constant object");
        *obj = asgn.value;
        return obj;
    }
 
    template <typename Obj, typename Fn>
    static decltype(auto) modify(Obj *obj, Fn fn) {
        static_assert(!std::is_const_v<Obj>, "Cannot modify constant object");
        return fn(obj);
    }
 
    template <typename Obj, typename... Selectors>
    static Obj *modify(Obj *obj, Index idx, Selectors &&...selectors) {
        static_assert(!std::is_const_v<Obj>, "Cannot modify constant object");
        BUG_CHECK(obj->size() > idx.value, "Index %1% out of bounds of %2%", idx.value, obj);
        modifyRef((*obj)[idx.value], std::forward<Selectors>(selectors)...);
        return obj;
    }
 
    template <typename Obj, typename To, typename... Selectors>
    static To *modify(Obj *obj, RTTI::Detail::ToType<To> cast, Selectors &&...selectors) {
        static_assert(!std::is_const_v<Obj>, "Cannot modify constant object");
        auto *casted = cast(obj);
        BUG_CHECK(casted, "Cast of %1% failed", obj);
        return modify(casted, std::forward<Selectors>(selectors)...);
    }
 
    template <typename Obj, typename T, typename Sub, typename... Selectors>
    static Obj *modify(Obj *obj, Sub T::*member, Selectors &&...selectors) {
        static_assert(!std::is_const_v<Obj>, "Cannot modify constant object");
        modifyRef(obj->*member, std::forward<Selectors>(selectors)...);
        return obj;
    }
 
    template <typename T, typename... Selectors>
    static void modifyRef(T &ref, Selectors &&...selectors) {
        if constexpr (std::is_pointer_v<T>) {
            ref = modify(ref->clone(), std::forward<Selectors>(selectors)...);
        } else {
            auto *res = modify(&ref, std::forward<Selectors>(selectors)...);
            if (&ref != res) {
                ref = *res;
            }
        }
    }
};
 
}  // namespace P4::IR::Traversal::Detail
 
#endif  // IR_IR_TRAVERSAL_INTERNAL_H_