flattenHeaders.h

/*
 * Copyright 2018 MNK Consulting, LLC.
 * SPDX-FileCopyrightText: 2018 MNK Consulting, LLC.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef MIDEND_FLATTENHEADERS_H_
#define MIDEND_FLATTENHEADERS_H_
 
#include "flattenInterfaceStructs.h"
#include "frontends/p4/typeChecking/typeChecker.h"
#include "ir/ir.h"
 
namespace P4 {

class FindHeaderTypesToReplace : public Inspector {
    P4::TypeMap *typeMap;
    AnnotationSelectionPolicy *policy;
    ordered_map<cstring, StructTypeReplacement<IR::Type_StructLike> *> replacement;
 
 public:
    explicit FindHeaderTypesToReplace(P4::TypeMap *typeMap, AnnotationSelectionPolicy *policy)
        : typeMap(typeMap), policy(policy) {
        setName("FindHeaderTypesToReplace");
        CHECK_NULL(typeMap);
    }
    bool preorder(const IR::Type_Header *type) override;
    void createReplacement(const IR::Type_Header *type, AnnotationSelectionPolicy *policy);
    StructTypeReplacement<IR::Type_StructLike> *getReplacement(const cstring name) const {
        return ::P4::get(replacement, name);
    }
    bool empty() const { return replacement.empty(); }
};

class ReplaceHeaders : public Transform, P4WriteContext {
    P4::TypeMap *typeMap;
    FindHeaderTypesToReplace *findHeaderTypesToReplace;
 
 public:
    explicit ReplaceHeaders(P4::TypeMap *typeMap,
                            FindHeaderTypesToReplace *findHeaderTypesToReplace)
        : typeMap(typeMap), findHeaderTypesToReplace(findHeaderTypesToReplace) {
        CHECK_NULL(typeMap);
        CHECK_NULL(findHeaderTypesToReplace);
        setName("ReplaceHeaders");
    }
 
    const IR::Node *preorder(IR::P4Program *program) override;
    const IR::Node *postorder(IR::Member *expression) override;
    const IR::Node *postorder(IR::Type_Header *type) override;
};
 
class FlattenHeaders final : public PassManager {
 public:
    FlattenHeaders(TypeMap *typeMap, AnnotationSelectionPolicy *policy = nullptr) {
        auto findHeadersToReplace = new FindHeaderTypesToReplace(typeMap, policy);
        passes.push_back(new TypeChecking(nullptr, typeMap));
        passes.push_back(findHeadersToReplace);
        passes.push_back(new ReplaceHeaders(typeMap, findHeadersToReplace));
        passes.push_back(new ClearTypeMap(typeMap));
        setName("FlattenHeaders");
    }
};
 
}  // namespace P4
 
#endif /* MIDEND_FLATTENHEADERS_H_ */