specialize.h

/*
 * Copyright 2016 VMware, Inc.
 * SPDX-FileCopyrightText: 2016 VMware, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef FRONTENDS_P4_SPECIALIZE_H_
#define FRONTENDS_P4_SPECIALIZE_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"
 
namespace P4 {
 
class FrontEndPolicy;  // full definition not needed here

struct SpecializationInfo {
    cstring name;
    const IR::IContainer *specialized;
    const IR::Vector<IR::Type> *typeArguments;
    IR::Vector<IR::Argument> *constructorArguments;
    IR::IndexedVector<IR::Declaration> declarations;
    const IR::Node *invocation;
    const IR::Node *insertBefore;
 
    SpecializationInfo(const IR::Node *invocation, const IR::IContainer *cont,
                       const IR::Node *insertion)
        : specialized(cont),
          typeArguments(nullptr),
          constructorArguments(new IR::Vector<IR::Argument>()),
          invocation(invocation),
          insertBefore(insertion) {
        CHECK_NULL(cont);
        CHECK_NULL(invocation);
        CHECK_NULL(insertion);
    }
    const IR::Type_Declaration *synthesize(const Visitor::Context *ctxt);
};

class SpecializationMap {
    ordered_map<const IR::Node *, SpecializationInfo *> specializations;
 
 public:
    TypeMap *typeMap = nullptr;
    void addSpecialization(const IR::ConstructorCallExpression *invocation,
                           const IR::IContainer *container, const IR::Node *insertion,
                           DeclarationLookup *declLookup, NameGenerator *nameGen);
    void addSpecialization(const IR::Declaration_Instance *invocation,
                           const IR::IContainer *container, const IR::Node *insertion,
                           DeclarationLookup *declLookup, NameGenerator *nameGen);
    IR::Vector<IR::Node> *getSpecializations(const IR::Node *insertion,
                                             const Visitor::Context *ctxt) const;
    cstring getName(const IR::Node *insertion) const {
        auto s = ::P4::get(specializations, insertion);
        if (s == nullptr) return nullptr;
        return s->name;
    }
    void clear() { specializations.clear(); }
};

class FindSpecializations : public Inspector, public ResolutionContext {
    SpecializationMap *specMap;
    MinimalNameGenerator nameGen;
 
 public:
    explicit FindSpecializations(SpecializationMap *specMap) : specMap(specMap) {
        CHECK_NULL(specMap);
        setName("FindSpecializations");
    }
 
    const IR::Node *findInsertionPoint() const;
    bool isSimpleConstant(const IR::Expression *expression) const;
    Visitor::profile_t init_apply(const IR::Node *node) override {
        auto rv = Inspector::init_apply(node);
 
        specMap->clear();
        node->apply(nameGen);
 
        return rv;
    }
    bool noParameters(const IR::IContainer *container);
 
    bool preorder(const IR::P4Parser *parser) override { return noParameters(parser); }
    bool preorder(const IR::P4Control *control) override { return noParameters(control); }
    void postorder(const IR::ConstructorCallExpression *expression) override;
    void postorder(const IR::Declaration_Instance *decl) override;
 
    bool preorder(const IR::Parameter *) override {
        // This prevents specialization of the default values of
        // parameters; we don't care to specialize these, we only need
        // to specialize them if they appear in a call.
        return false;
    }
};

class Specialize : public Transform {
    SpecializationMap *specMap;
    const IR::Node *instantiate(const IR::Node *node, const Visitor::Context *ctxt);
 
 public:
    explicit Specialize(SpecializationMap *specMap) : specMap(specMap) {
        CHECK_NULL(specMap);
        setName("Specialize");
    }
    const IR::Node *postorder(IR::P4Parser *parser) override {
        return instantiate(parser, getContext());
    }
    // skip packages
    const IR::Node *preorder(IR::Type_Package *package) override {
        prune();
        return package;
    }
    const IR::Node *postorder(IR::P4Control *control) override {
        return instantiate(control, getContext());
    }
    const IR::Node *postorder(IR::ConstructorCallExpression *expression) override;
    const IR::Node *postorder(IR::Declaration_Instance *) override;
};

class SpecializeAll : public PassRepeated {
    SpecializationMap specMap;
 
 public:
    SpecializeAll(TypeMap *typeMap, FrontEndPolicy *policy);
};
 
}  // namespace P4
 
#endif /* FRONTENDS_P4_SPECIALIZE_H_ */