uniqueNames.h

/*
Copyright 2013-present Barefoot Networks, 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 FRONTENDS_P4_UNIQUENAMES_H_
#define FRONTENDS_P4_UNIQUENAMES_H_
 
#include "frontends/common/resolveReferences/referenceMap.h"
#include "frontends/common/resolveReferences/resolveReferences.h"
#include "frontends/p4/typeMap.h"
#include "ir/ir.h"
#include "ir/pass_manager.h"
#include "ir/visitor.h"
 
namespace P4 {
 
class RenameMap {
    std::map<const IR::IDeclaration *, cstring> newName;
    std::map<const IR::MethodCallExpression *, const IR::P4Action *> actionCall;
 
 public:
    void setNewName(const IR::IDeclaration *decl, cstring name, bool allowOverride = false);

    cstring getName(const IR::IDeclaration *decl) const {
        auto n = get(decl);
        BUG_CHECK(n.has_value(), "%1%: no new name", decl);
        return *n;
    }

    bool toRename(const IR::IDeclaration *decl) const {
        CHECK_NULL(decl);
        return newName.find(decl) != newName.end();
    }

    std::optional<cstring> get(const IR::IDeclaration *decl) const {
        CHECK_NULL(decl);
        if (auto it = newName.find(decl); it != newName.end()) {
            return it->second;
        }
        return {};
    }
 
    void foundInTable(const IR::P4Action *action);
    void markActionCall(const IR::P4Action *action, const IR::MethodCallExpression *call);
    const IR::P4Action *actionCalled(const IR::MethodCallExpression *expression) const;
};

class UniqueNames : public PassManager {
 private:
    RenameMap *renameMap;
 
 public:
    UniqueNames();
};

class FindSymbols : public Inspector {
    MinimalNameGenerator nameGen;  // used to generate new names
    RenameMap *renameMap;
 
 public:
    bool isTopLevel() const {
        return !isInContext<IR::P4Parser>() && !isInContext<IR::P4Control>();
    }
    explicit FindSymbols(RenameMap *renameMap) : renameMap(renameMap) {
        CHECK_NULL(renameMap);
        setName("FindSymbols");
    }
    profile_t init_apply(const IR::Node *node) override {
        auto rv = Inspector::init_apply(node);
        node->apply(nameGen);
        return rv;
    }
 
    void doDecl(const IR::Declaration *decl) {
        cstring newName = nameGen.newName(decl->getName().string_view());
        renameMap->setNewName(decl, newName);
    }
    void postorder(const IR::Declaration_Variable *decl) override { doDecl(decl); }
    void postorder(const IR::Declaration_Constant *decl) override {
        // Skip toplevel constants with names like __
        // We assume that these do not clash and no new symbols with
        // these names will be added.
        if (decl->getName().name.startsWith("__") && getParent<IR::P4Program>()) return;
        doDecl(decl);
    }
    void postorder(const IR::Declaration_Instance *decl) override {
        if (!isTopLevel()) doDecl(decl);
    }
    void postorder(const IR::P4Table *decl) override { doDecl(decl); }
    void postorder(const IR::P4Action *decl) override {
        if (!isTopLevel()) doDecl(decl);
    }
    void postorder(const IR::P4ValueSet *decl) override {
        if (!isTopLevel()) doDecl(decl);
    }
};
 
class RenameSymbols : public Transform, public ResolutionContext {
 protected:
    RenameMap *renameMap;

    IR::ID *getName() const;
    IR::ID *getName(const IR::IDeclaration *decl) const;

    template <typename D>
    const IR::Node *renameDeclWithNameAnnotation(D *decl) {
        auto name = getName();
        if (name != nullptr && *name != decl->name) {
            decl->addAnnotationIfNew(IR::Annotation::nameAnnotation,
                                     new IR::StringLiteral(decl->name));
            decl->name = *name;
        }
        return decl;
    }
 
 public:
    explicit RenameSymbols(RenameMap *renameMap) : renameMap(renameMap) {
        CHECK_NULL(renameMap);
        visitDagOnce = false;
        setName("RenameSymbols");
    }
    const IR::Node *postorder(IR::Declaration_Variable *decl) override;
    const IR::Node *postorder(IR::Declaration_Constant *decl) override;
    const IR::Node *postorder(IR::PathExpression *expression) override;
    const IR::Node *postorder(IR::Declaration_Instance *decl) override;
    const IR::Node *postorder(IR::P4Table *decl) override;
    const IR::Node *postorder(IR::P4Action *decl) override;
    const IR::Node *postorder(IR::P4ValueSet *decl) override;
    const IR::Node *postorder(IR::Parameter *param) override;
    const IR::Node *postorder(IR::Argument *argument) override;
};

class FindParameters : public Inspector {
    MinimalNameGenerator nameGen;
    RenameMap *renameMap;
 
    void doParameters(const IR::ParameterList *pl) {
        for (auto p : pl->parameters) {
            cstring newName = nameGen.newName(p->name.string_view());
            renameMap->setNewName(p, newName);
        }
    }
 
 public:
    explicit FindParameters(RenameMap *renameMap) : renameMap(renameMap) {
        CHECK_NULL(renameMap);
        setName("FindParameters");
    }
    void postorder(const IR::P4Action *action) override { doParameters(action->parameters); }
    profile_t init_apply(const IR::Node *node) override;
};

class UniqueParameters : public PassManager {
 private:
    RenameMap *renameMap;
 
 public:
    explicit UniqueParameters(TypeMap *typeMap);
};
 
}  // namespace P4
 
#endif /* FRONTENDS_P4_UNIQUENAMES_H_ */