methodInstance.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_METHODINSTANCE_H_
#define FRONTENDS_P4_METHODINSTANCE_H_
 
#include "frontends/common/resolveReferences/referenceMap.h"
#include "frontends/p4/parameterSubstitution.h"
#include "frontends/p4/typeMap.h"
#include "ir/ir.h"
 
namespace P4 {
 
class InstanceBase : public ICastable {
 protected:
    virtual ~InstanceBase() {}
 
 public:
    ParameterSubstitution substitution;
    TypeVariableSubstitution typeSubstitution;
 
    DECLARE_TYPEINFO(InstanceBase);
};

class MethodInstance : public InstanceBase {
 protected:
    MethodInstance(const IR::MethodCallExpression *mce, const IR::IDeclaration *decl,
                   const IR::Type_MethodBase *originalMethodType,
                   const IR::Type_MethodBase *actualMethodType)
        : expr(mce),
          object(decl),
          originalMethodType(originalMethodType),
          actualMethodType(actualMethodType) {
        CHECK_NULL(mce);
        CHECK_NULL(originalMethodType);
        CHECK_NULL(actualMethodType);
    }
 
    void bindParameters() {
        auto params = getActualParameters();
        substitution.populate(params, expr->arguments);
    }
 
 public:
    const IR::MethodCallExpression *expr;
    const IR::IDeclaration *object;
    const IR::Type_MethodBase *originalMethodType;
    const IR::Type_MethodBase *actualMethodType;
    virtual bool isApply() const { return false; }

    static MethodInstance *resolve(const IR::MethodCallExpression *mce,
                                   const DeclarationLookup *refMap, TypeMap *typeMap,
                                   bool useExpressionType = false,
                                   const Visitor::Context *ctxt = nullptr, bool incomplete = false);
    static MethodInstance *resolve(const IR::MethodCallExpression *mce,
                                   const DeclarationLookup *refMap, TypeMap *typeMap,
                                   const Visitor::Context *ctxt, bool incomplete = false) {
        return resolve(mce, refMap, typeMap, false, ctxt, incomplete);
    }
    static MethodInstance *resolve(const IR::MethodCallStatement *mcs,
                                   const DeclarationLookup *refMap, TypeMap *typeMap,
                                   const Visitor::Context *ctxt = nullptr) {
        return resolve(mcs->methodCall, refMap, typeMap, false, ctxt, false);
    }
    static MethodInstance *resolve(const IR::MethodCallExpression *mce,
                                   const DeclarationLookup *refMap,
                                   const Visitor::Context *ctxt = nullptr) {
        return resolve(mce, refMap, nullptr, true, ctxt, false);
    }
    static MethodInstance *resolve(const IR::MethodCallStatement *mcs,
                                   const DeclarationLookup *refMap,
                                   const Visitor::Context *ctxt = nullptr) {
        return resolve(mcs->methodCall, refMap, nullptr, true, ctxt, false);
    }
 
    const IR::ParameterList *getOriginalParameters() const {
        return originalMethodType->parameters;
    }
    const IR::ParameterList *getActualParameters() const { return actualMethodType->parameters; }
 
    DECLARE_TYPEINFO(MethodInstance, InstanceBase);
};

class ApplyMethod final : public MethodInstance {
    ApplyMethod(const IR::MethodCallExpression *expr, const IR::IDeclaration *decl,
                const IR::IApply *applyObject)
        : MethodInstance(expr, decl, applyObject->getApplyMethodType(),
                         applyObject->getApplyMethodType()),
          applyObject(applyObject) {
        CHECK_NULL(applyObject);
        bindParameters();
    }
    friend class MethodInstance;
 
 public:
    const IR::IApply *applyObject;
    bool isApply() const override { return true; }
    bool isTableApply() const { return object->is<IR::P4Table>(); }
 
    DECLARE_TYPEINFO(ApplyMethod, MethodInstance);
};

class ExternMethod final : public MethodInstance {
    ExternMethod(const IR::MethodCallExpression *expr, const IR::IDeclaration *decl,
                 const IR::Method *method, const IR::Type_Extern *originalExternType,
                 const IR::Type_Method *originalMethodType, const IR::Type_Extern *actualExternType,
                 const IR::Type_Method *actualMethodType, bool incomplete)
        : MethodInstance(expr, decl, originalMethodType, actualMethodType),
          method(method),
          originalExternType(originalExternType),
          actualExternType(actualExternType) {
        CHECK_NULL(method);
        CHECK_NULL(originalExternType);
        CHECK_NULL(actualExternType);
        bindParameters();
        if (!incomplete)
            typeSubstitution.setBindings(expr, method->type->typeParameters, expr->typeArguments);
    }
    friend class MethodInstance;
 
 public:
    const IR::Method *method;
    const IR::Type_Extern *originalExternType;  // type of object method is applied to
    const IR::Type_Extern *actualExternType;    // with type variables substituted

    // If this method is abstract, will consist of (just) the concrete implementation,
    // otherwise will consist of those methods that are @synchronous with this
    std::vector<const IR::IDeclaration *> mayCall() const;
 
    DECLARE_TYPEINFO(ExternMethod, MethodInstance);
};

class ExternFunction final : public MethodInstance {
    ExternFunction(const IR::MethodCallExpression *expr, const IR::Method *method,
                   const IR::Type_Method *originalMethodType,
                   const IR::Type_Method *actualMethodType, bool incomplete)
        : MethodInstance(expr, nullptr, originalMethodType, actualMethodType), method(method) {
        CHECK_NULL(method);
        bindParameters();
        if (!incomplete)
            typeSubstitution.setBindings(expr, method->type->typeParameters, expr->typeArguments);
    }
    friend class MethodInstance;
 
 public:
    const IR::Method *method;
 
    DECLARE_TYPEINFO(ExternFunction, MethodInstance);
};

class ActionCall final : public MethodInstance {
    ActionCall(const IR::MethodCallExpression *expr, const IR::P4Action *action,
               const IR::Type_Action *actionType)
        :  // Actions are never generic
          MethodInstance(expr, nullptr, actionType, actionType),
          action(action) {
        CHECK_NULL(action);
        bindParameters();
    }
    friend class MethodInstance;
 
 public:
    const IR::P4Action *action;
    const IR::P4Action *specialize(const DeclarationLookup *refMap) const;
 
    DECLARE_TYPEINFO(ActionCall, MethodInstance);
};

class FunctionCall final : public MethodInstance {
    FunctionCall(const IR::MethodCallExpression *expr, const IR::Function *function,
                 const IR::Type_Method *originalMethodType, const IR::Type_Method *actualMethodType,
                 bool incomplete)
        : MethodInstance(expr, nullptr, originalMethodType, actualMethodType), function(function) {
        CHECK_NULL(function);
        bindParameters();
        if (!incomplete)
            typeSubstitution.setBindings(function, function->type->typeParameters,
                                         expr->typeArguments);
    }
    friend class MethodInstance;
 
 public:
    const IR::Function *function;
 
    DECLARE_TYPEINFO(FunctionCall, MethodInstance);
};

class BuiltInMethod final : public MethodInstance {
    friend class MethodInstance;
    BuiltInMethod(const IR::MethodCallExpression *expr, IR::ID name,
                  const IR::Expression *appliedTo, const IR::Type_Method *methodType)
        : MethodInstance(expr, nullptr, methodType, methodType), name(name), appliedTo(appliedTo) {
        CHECK_NULL(appliedTo);
        bindParameters();
    }
 
 public:
    const IR::ID name;
    const IR::Expression *appliedTo;  // object is an expression
 
    DECLARE_TYPEINFO(BuiltInMethod, MethodInstance);
};


class ConstructorCall : public InstanceBase {
 protected:
    virtual ~ConstructorCall() {}
    explicit ConstructorCall(const IR::ConstructorCallExpression *cce) : cce(cce) {
        CHECK_NULL(cce);
    }
 
 public:
    const IR::ConstructorCallExpression *cce = nullptr;
    const IR::Vector<IR::Type> *typeArguments = nullptr;
    const IR::ParameterList *constructorParameters = nullptr;
    static ConstructorCall *resolve(const IR::ConstructorCallExpression *cce,
                                    const DeclarationLookup *refMap, TypeMap *typeMap);
    DECLARE_TYPEINFO(ConstructorCall, InstanceBase);
};

class ExternConstructorCall : public ConstructorCall {
    explicit ExternConstructorCall(const IR::ConstructorCallExpression *cce,
                                   const IR::Type_Extern *type, const IR::Method *constructor)
        : ConstructorCall(cce), type(type), constructor(constructor) {
        CHECK_NULL(type);
        CHECK_NULL(constructor);
    }
    friend class ConstructorCall;
 
 public:
    const IR::Type_Extern *type;    // actual extern declaration in program IR
    const IR::Method *constructor;  // that is being invoked
 
    DECLARE_TYPEINFO(ExternConstructorCall, ConstructorCall);
};

class ContainerConstructorCall : public ConstructorCall {
    explicit ContainerConstructorCall(const IR::ConstructorCallExpression *cce,
                                      const IR::IContainer *cont)
        : ConstructorCall(cce), container(cont) {
        CHECK_NULL(cont);
    }
    friend class ConstructorCall;
 
 public:
    const IR::IContainer *container;  // actual container in program IR
 
    DECLARE_TYPEINFO(ContainerConstructorCall, ConstructorCall);
};


class Instantiation : public InstanceBase {
 protected:
    void substitute() {
        substitution.populate(constructorParameters, constructorArguments);
        typeSubstitution.setBindings(instance, typeParameters, typeArguments);
    }
 
 public:
    Instantiation(const IR::Declaration_Instance *instance,
                  const IR::Vector<IR::Type> *typeArguments)
        : instance(instance), typeArguments(typeArguments) {
        CHECK_NULL(instance);
        constructorArguments = instance->arguments;
    }
 
    const IR::Declaration_Instance *instance;
    const IR::Vector<IR::Type> *typeArguments;
    const IR::Vector<IR::Argument> *constructorArguments;
    const IR::ParameterList *constructorParameters = nullptr;
    const IR::TypeParameters *typeParameters = nullptr;
 
    static Instantiation *resolve(const IR::Declaration_Instance *instance,
                                  DeclarationLookup *refMap, TypeMap *typeMap);
 
    DECLARE_TYPEINFO(Instantiation, InstanceBase);
};
 
class ExternInstantiation : public Instantiation {
 public:
    ExternInstantiation(const IR::Declaration_Instance *instance,
                        const IR::Vector<IR::Type> *typeArguments, const IR::Type_Extern *type)
        : Instantiation(instance, typeArguments), type(type) {
        auto constructor = type->lookupConstructor(constructorArguments);
        BUG_CHECK(constructor, "%1%: could not find constructor", type);
        constructorParameters = constructor->type->parameters;
        typeParameters = type->typeParameters;
        substitute();
    }
    const IR::Type_Extern *type;
 
    DECLARE_TYPEINFO(ExternInstantiation, Instantiation);
};
 
class PackageInstantiation : public Instantiation {
 public:
    PackageInstantiation(const IR::Declaration_Instance *instance,
                         const IR::Vector<IR::Type> *typeArguments, const IR::Type_Package *package)
        : Instantiation(instance, typeArguments), package(package) {
        constructorParameters = package->getConstructorParameters();
        typeParameters = package->typeParameters;
        substitute();
    }
    const IR::Type_Package *package;
 
    DECLARE_TYPEINFO(PackageInstantiation, Instantiation);
};
 
class ParserInstantiation : public Instantiation {
 public:
    ParserInstantiation(const IR::Declaration_Instance *instance,
                        const IR::Vector<IR::Type> *typeArguments, const IR::P4Parser *parser)
        : Instantiation(instance, typeArguments), parser(parser) {
        typeParameters = parser->type->typeParameters;
        constructorParameters = parser->getConstructorParameters();
        substitute();
    }
    const IR::P4Parser *parser;
 
    DECLARE_TYPEINFO(ParserInstantiation, Instantiation);
};
 
class ControlInstantiation : public Instantiation {
 public:
    ControlInstantiation(const IR::Declaration_Instance *instance,
                         const IR::Vector<IR::Type> *typeArguments, const IR::P4Control *control)
        : Instantiation(instance, typeArguments), control(control) {
        typeParameters = control->type->typeParameters;
        constructorParameters = control->getConstructorParameters();
        substitute();
    }
    const IR::P4Control *control;
 
    DECLARE_TYPEINFO(ControlInstantiation, Instantiation);
};
 
}  // namespace P4
 
#endif /* FRONTENDS_P4_METHODINSTANCE_H_ */