eliminateTuples.h

/*
Copyright 2016 VMware, Inc.
 
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
 
    http://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
 
#ifndef MIDEND_ELIMINATETUPLES_H_
#define MIDEND_ELIMINATETUPLES_H_
 
#include "frontends/common/resolveReferences/resolveReferences.h"
#include "frontends/p4/typeChecking/typeChecker.h"
#include "ir/ir.h"
 
namespace P4 {

class ReplacementMap {
    ordered_map<const IR::Type *, const IR::Type_Struct *> replacement;
    std::set<const IR::Type_Struct *> inserted;
    const IR::Type *convertType(const IR::Type *type);
 
 public:
    P4::NameGenerator *ng;
    P4::TypeMap *typeMap;
 
    ReplacementMap(NameGenerator *ng, TypeMap *typeMap) : ng(ng), typeMap(typeMap) {
        CHECK_NULL(ng);
        CHECK_NULL(typeMap);
    }
    const IR::Type_Struct *getReplacement(const IR::Type_BaseList *tt);
    IR::IndexedVector<IR::Node> *getNewReplacements();
};

class DoReplaceTuples final : public Transform {
    ReplacementMap *repl;
 
 public:
    DoReplaceTuples(ReferenceMap *refMap, TypeMap *typeMap)
        : repl(new ReplacementMap(refMap, typeMap)) {
        setName("DoReplaceTuples");
    }
    const IR::Node *skip(const IR::Node *node) {
        prune();
        return node;
    }
    const IR::Node *postorder(IR::Type_BaseList *type) override;
    const IR::Node *insertReplacements(const IR::Node *before);
    const IR::Node *postorder(IR::Type_Struct *type) override { return insertReplacements(type); }
    const IR::Node *postorder(IR::ArrayIndex *expression) override;
    const IR::Node *postorder(IR::Type_Typedef *type) override { return insertReplacements(type); }
    const IR::Node *postorder(IR::Type_Newtype *type) override { return insertReplacements(type); }
    const IR::Node *postorder(IR::P4Parser *parser) override { return insertReplacements(parser); }
    const IR::Node *postorder(IR::P4Control *control) override {
        return insertReplacements(control);
    }
    const IR::Node *postorder(IR::Method *method) override { return insertReplacements(method); }
    const IR::Node *postorder(IR::Type_Extern *ext) override { return insertReplacements(ext); }
    const IR::Node *postorder(IR::Declaration_Instance *decl) override {
        return insertReplacements(decl);
    }
    const IR::Node *preorder(IR::P4ValueSet *set) override {
        // Disable substitution of type parameters for value sets.
        // We want to keep these as tuples.
        return skip(set);
    }
    const IR::Node *preorder(IR::P4ListExpression *expression) override { return skip(expression); }
    const IR::Node *preorder(IR::Type_P4List *list) override { return skip(list); }
};
 
class EliminateTuples final : public PassManager {
 public:
    EliminateTuples(ReferenceMap *refMap, TypeMap *typeMap, TypeChecking *typeChecking = nullptr,
                    TypeInference *typeInference = nullptr) {
        if (!typeChecking) typeChecking = new TypeChecking(refMap, typeMap);
        passes.push_back(typeChecking);
        passes.push_back(new DoReplaceTuples(refMap, typeMap));
        passes.push_back(new ClearTypeMap(typeMap));
        // We do a round of type-checking which may mutate the program.
        // This will convert some ListExpressions
        // into StructExpression where tuples were converted
        // to structs.
        passes.push_back(new ResolveReferences(refMap));
        if (!typeInference) typeInference = new TypeInference(typeMap, false);
        passes.push_back(typeInference);
        setName("EliminateTuples");
    }
};
 
}  // namespace P4
 
#endif /* MIDEND_ELIMINATETUPLES_H_ */