abstract_stepper.h

/*
 * SPDX-FileCopyrightText: 2022 The P4 Language Consortium
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef BACKENDS_P4TOOLS_MODULES_TESTGEN_CORE_SMALL_STEP_ABSTRACT_STEPPER_H_
#define BACKENDS_P4TOOLS_MODULES_TESTGEN_CORE_SMALL_STEP_ABSTRACT_STEPPER_H_
 
#include <functional>
#include <optional>
#include <string>
 
#include "ir/ir.h"
#include "ir/node.h"
#include "ir/solver.h"
#include "ir/vector.h"
#include "ir/visitor.h"
 
#include "backends/p4tools/modules/testgen/core/program_info.h"
#include "backends/p4tools/modules/testgen/core/small_step/small_step.h"
#include "backends/p4tools/modules/testgen/lib/continuation.h"
#include "backends/p4tools/modules/testgen/lib/execution_state.h"
 
namespace P4::P4Tools::P4Testgen {

class AbstractStepper : public Inspector {
 public:
    using Branch = SmallStepEvaluator::Branch;
    using Result = SmallStepEvaluator::Result;

    Result step(const IR::Node *);

    bool preorder(const IR::Node *) override;
 
    AbstractStepper(ExecutionState &state, AbstractSolver &solver, const ProgramInfo &programInfo);
 
 protected:
    const ProgramInfo &programInfo;

    ExecutionState &state;

    AbstractSolver &solver;

    Result result;

    virtual std::string getClassName() = 0;
 
    virtual const ProgramInfo &getProgramInfo() const;

    void logStep(const IR::Node *node);

    static void checkMemberInvariant(const IR::Node *node);
 
    /* *****************************************************************************************
     * Transition helper functions
     * ***************************************************************************************** */

    bool stepSymbolicValue(const IR::Node *);

    bool stepToException(Continuation::Exception);

    static bool stepToSubexpr(
        const IR::Expression *subexpr, SmallStepEvaluator::Result &result,
        const ExecutionState &state,
        std::function<const Continuation::Command(const Continuation::Parameter *)> rebuildCmd);

    static bool stepToListSubexpr(
        const IR::BaseListExpression *subexpr, SmallStepEvaluator::Result &result,
        const ExecutionState &state,
        std::function<const Continuation::Command(const IR::BaseListExpression *)> rebuildCmd);

    static bool stepToStructSubexpr(
        const IR::StructExpression *subexpr, SmallStepEvaluator::Result &result,
        const ExecutionState &state,
        std::function<const Continuation::Command(const IR::StructExpression *)> rebuildCmd);

    bool stepGetHeaderValidity(const IR::StateVariable &headerRef);

    void setHeaderValidity(const IR::StateVariable &headerRef, bool validity,
                           ExecutionState &state);

    bool stepSetHeaderValidity(const IR::StateVariable &headerRef, bool validity);

    bool stepStackPushPopFront(const IR::Expression *stackRef, const IR::Vector<IR::Argument> *args,
                               bool isPush = true);

    const IR::Literal *evaluateExpression(const IR::Expression *expr,
                                          std::optional<const IR::Expression *> cond) const;

    void setTargetUninitialized(ExecutionState &nextState, const IR::StateVariable &ref,
                                bool forceTaint) const;

    void declareStructLike(ExecutionState &nextState, const IR::StateVariable &parentExpr,
                           bool forceTaint = false) const;

    void declareBaseType(ExecutionState &nextState, const IR::StateVariable &paramPath,
                         const IR::Type_Base *baseType) const;
};
 
}  // namespace P4::P4Tools::P4Testgen
 
#endif /* BACKENDS_P4TOOLS_MODULES_TESTGEN_CORE_SMALL_STEP_ABSTRACT_STEPPER_H_ */