abstract_execution_state.h

/*
 * SPDX-FileCopyrightText: 2023 The P4 Language Consortium
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef BACKENDS_P4TOOLS_COMMON_CORE_ABSTRACT_EXECUTION_STATE_H_
#define BACKENDS_P4TOOLS_COMMON_CORE_ABSTRACT_EXECUTION_STATE_H_
 
#include "backends/p4tools/common/core/target.h"
#include "backends/p4tools/common/lib/namespace_context.h"
#include "backends/p4tools/common/lib/symbolic_env.h"
#include "ir/ir.h"
 
namespace P4::P4Tools {

class AbstractExecutionState {
 protected:
    const NamespaceContext *namespaces;

    SymbolicEnv env;
 
    /* =========================================================================================
     *  Constructors
     * ========================================================================================= */
    AbstractExecutionState(const AbstractExecutionState &) = default;

    AbstractExecutionState();

    AbstractExecutionState &operator=(const AbstractExecutionState &) = default;
 
 public:
    explicit AbstractExecutionState(const IR::P4Program *program);
    virtual ~AbstractExecutionState() = default;
    AbstractExecutionState &operator=(AbstractExecutionState &&) = delete;

    [[nodiscard]] virtual AbstractExecutionState &clone() const = 0;
 
    AbstractExecutionState(AbstractExecutionState &&) = default;
 
    /* =========================================================================================
     *  Accessors
     * ========================================================================================= */
 public:
    [[nodiscard]] virtual const IR::Expression *get(const IR::StateVariable &var) const = 0;

    virtual void set(const IR::StateVariable &var, const IR::Expression *value) = 0;

    [[nodiscard]] bool exists(const IR::StateVariable &var) const;

    [[nodiscard]] const SymbolicEnv &getSymbolicEnv() const;

    void printSymbolicEnv(std::ostream &out = std::cout) const;
 
 public:
    [[nodiscard]] const IR::IDeclaration *findDecl(const IR::Path *path) const;

    [[nodiscard]] const IR::IDeclaration *findDecl(const IR::PathExpression *pathExpr) const;

    [[nodiscard]] const IR::Type *resolveType(const IR::Type *type) const;

    [[nodiscard]] const NamespaceContext *getNamespaceContext() const;

    void setNamespaceContext(const NamespaceContext *namespaces);

    void pushNamespace(const IR::INamespace *ns);

    void popNamespace();
 
    /* =========================================================================================
     *  General utilities involving ExecutionState.
     * ========================================================================================= */
 protected:
    const IR::Expression *convertToComplexExpression(const IR::StateVariable &parent) const;

    static std::vector<const IR::Expression *> flattenComplexExpression(
        const IR::Expression *inputExpression, std::vector<const IR::Expression *> &flatValids);
 
 public:
    [[nodiscard]] std::vector<IR::StateVariable> getFlatFields(
        const IR::StateVariable &parent,
        std::vector<IR::StateVariable> *validVector = nullptr) const;

    void initializeStructLike(const Target &target, const IR::StateVariable &targetVar,
                              bool forceTaint);

    void assignStructLike(const IR::StateVariable &left, const IR::Expression *right);

    void setStructLike(const IR::StateVariable &targetVar, const IR::StateVariable &sourceVar);

    void declareVariable(const Target &target, const IR::Declaration_Variable &declVar);

    void copyIn(const Target &target, const IR::Parameter *internalParam,
                cstring externalParamName);

    void copyOut(const IR::Parameter *internalParam, cstring externalParamName);

    void initializeBlockParams(const Target &target, const IR::Type_Declaration *typeDecl,
                               const std::vector<cstring> *blockParams);

    const IR::P4Table *findTable(const IR::Member *member) const;
 
    // Try to extract and @return the IR::P4Action from the action call.
    [[nodiscard]] const IR::P4Action *getP4Action(const IR::MethodCallExpression *actionExpr) const;
};
 
}  // namespace P4::P4Tools
 
#endif /* BACKENDS_P4TOOLS_COMMON_CORE_ABSTRACT_EXECUTION_STATE_H_ */