Re: problem with function calling tracker

From:
Frank Bergemann <FBergemann@web.de>
Newsgroups:
comp.lang.c++.moderated
Date:
Fri, 4 Nov 2011 16:39:31 -0700 (PDT)
Message-ID:
<63b022c1-f6dd-4ee5-bed0-20ce54f0bb49@hv4g2000vbb.googlegroups.com>
It works (somehow).
But i have still a problem.
I can't disable copy c'tor for class ArgCommon and the classes derived
from it
(prepared but disabled in code below).
However, actually the object to track (function argument) is not
copied - already know.
So it might not be needed to disable copy c'tor for ArgCommon and
derived classes(?!)

Can you help me, please?
- many thanks!

Here is the latest version
(For you convenience, you can download tgz with Makefile from here:
http://frank-bergemann.jimdo.com/programming/c/functiontracker/
at the bottom of the page)

----------------------------------- FunctionTracker.h
------------------------------------
/*
 * FunctionTracker.h
 *
 * Created on: Oct 30, 2011
 * Author: frank
 */

#ifndef __FUNCTION_TRACKER_H__
#define __FUNCTION_TRACKER_H__

#include <iostream>
#include <iomanip>
#include <utility> // std::forward<>
#include <tr1/tuple> // std::tr1::tuple<>

/*
 * TODO:
 * +) use namespace
 * +) hide internal definitions from user
 * +) do w/o FunctionTracker.cpp
 * +) don't directly log to std::cerr
 * option: static FunctionTracker::Setup to pass stream? (functor?)
 */

/**
 * function parameter type (in, out, inout)
 */
typedef enum
{
    In_c = 1,
    Out_c = 2,
    InOut_c = In_c | Out_c
} ParamType_t;

/**
 * non-template base class for function parameters
 */
struct ArgCommon
{
    char const * const _name;
    ParamType_t const _type;
    ArgCommon(
        char const * const name,
        ParamType_t const type)
    : _name(name),
      _type(type)
    { };

// ArgCommon(const ArgCommon & rhs) = delete;
};

/**
 * template'd function parameter class
 * extending ArgCommon
 */
template <typename T>
struct Arg : public ArgCommon
{
    T const & _value;

    Arg(
        char const * const name,
        ParamType_t const type,
        T const & value)
    : ArgCommon(name, type),
      _value(value)
    { };

// Arg(const Arg & rhs) = delete;
};

/*
 * Abbreviations for IN, OUT & INOUT parameter
 */

/**
 * IN parameter
 */
template <typename T>
struct InArg : public Arg<T>
{
    InArg(
        char const * const name,
        T const & value)
    : Arg<T>(name, In_c, value)
    { };

// InArg(const InArg & rhs) = delete;
};

/**
 * OUT parameter
 */
template <typename T>
struct OutArg : public Arg<T>
{
    OutArg(
        char const * const name,
        T const & value)
    : Arg<T>(name, Out_c, value)
    { };

// OutArg(const OutArg & rhs) = delete;
};

/**
 * INOUT parameter
 */
template <typename T>
struct InOutArg : public Arg<T>
{
    InOutArg(
        char const * const name,
        T const & value)
    : Arg<T>(name, InOut_c, value)
    { };

    InOutArg(const InOutArg & rhs) = delete;
};

// variadic template type list transformation
template <typename ...Types>
struct ArgTuple
{
    /*
     * TODO: this implies copying of the args!
     * But the version to use references doesn't work!
     */
#if 0
    typedef typename std::tr1::tuple<const Arg<Types>&...> Type;
#endif
    typedef typename std::tr1::tuple<const Arg<Types>...> Type;

    ArgTuple(const ArgTuple & rhs) = delete;
};

/**
 * ostream helper for function paramter
 * supposes ostream helper for the parameter type is avail
 */
template <typename T>
std::ostream &operator<<(
        std::ostream &out,
        const Arg<T> &arg)
{
    out << arg._name << " => '" << arg._value << "'";
    return out;
}

struct FunctionTrackerShared {
    static int _level;
};

template <typename ParamTuple>
class FunctionTrackerImpl
{
    private:
        char const * const _funcName;

        /*
         * TODO:
         * This implies copying
         * Try to do with const reference (rvalue reference?)
         * But the version to use references doesn't work!
         */
#if 0
        const ParamTuple & _params;
#endif
        const ParamTuple _params;

    protected:
        FunctionTrackerImpl(
            char const* const funcName,
            ParamTuple && params)
        : _funcName(funcName?funcName:"<unknown>"),
          _params(std::forward<ParamTuple>(params))
        {
            if (FunctionTrackerShared::_level > 0) {
                std::cerr << std::setw(FunctionTrackerShared::_level) << ' ';
            }
            std::cerr << _funcName << ": enter with ";
            PrintInput(_params);
            std::cerr << std::endl;
            ++FunctionTrackerShared::_level;
        }

        FunctionTrackerImpl(const FunctionTrackerImpl & rhs)
        : _funcName(rhs._funcName),
          _params(rhs._params)
        {
            std::cerr << "!!! _EnterExitMsgImpl copy c'tor !!!" << std::endl;
        }

        ~FunctionTrackerImpl()
        {
            --FunctionTrackerShared::_level;
            if (FunctionTrackerShared::_level > 0) {
                std::cerr << std::setw(FunctionTrackerShared::_level) << ' ';
            }
            std::cerr << _funcName << ": exit with ";
            PrintOutput(_params);
            std::cerr << std::endl;
        }

        void PrintInput(
            const ParamTuple & params)
        {
            std::cerr << "input: ";
            PrintTuple(In_c, params);
        }

        void PrintOutput(
            const ParamTuple & params)
        {
            std::cerr << "output: ";
            PrintTuple(Out_c, params);
        }

        template<std::size_t I = 0, typename... Tp>
        inline typename std::enable_if<I == sizeof...(Tp), void>::type
        PrintTuple(ParamType_t const paramType, const
std::tr1::tuple<Tp...>& t)
        { }

        template<std::size_t I = 0, typename... Tp>
        inline typename std::enable_if<I < sizeof...(Tp), void>::type
        PrintTuple(ParamType_t const paramType, const
std::tr1::tuple<Tp...>& t)
        {
            ArgCommon arg = std::tr1::get<I>(t);
            if (paramType == arg._type) {
                std::cerr << std::tr1::get<I>(t) << ", ";
            }
            PrintTuple<I + 1, Tp...>(paramType, t);
        }

};

template <typename... Types>
class FunctionTracker : public FunctionTrackerImpl< typename
ArgTuple<Types...>::Type >
{
private:
        typedef FunctionTrackerImpl< typename ArgTuple<Types...>::Type >
BaseType;

        typedef typename ArgTuple<Types...>::Type ParamTuple;

        FunctionTracker(
                char const * const funcName,
                ParamTuple && params)
        : FunctionTrackerImpl<ParamTuple>(funcName,
std::forward<ParamTuple>(params))
        { };

public:
        FunctionTracker(const FunctionTracker & rhs)
        : BaseType(rhs)
        { };

        template <typename... Args>
        static FunctionTracker make(
            char const * const funcName,
            Args&&... args)
        {
            return FunctionTracker<Types...>(funcName,
std::tr1::make_tuple(std::forward<Args>(args)...));
        };
};

#endif /*__FUNCTION_TRACKER_H__*/

-----------------------------------------------------------------------------------------------
--------------------------------- FunctionTracker.cpp
-----------------------------------------
/*
 * FunctionTracker.cpp
 *
 * Created on: Nov 1, 2011
 * Author: frank
 */

#include "FunctionTracker.h"

int FunctionTrackerShared::_level = 0;
-----------------------------------------------------------------------------------------------
--------------------------------- FunctionTrackerTest.cpp
-------------------------------------
/*
 * FunctionTrackerTest.cpp
 *
 * Created on: Oct 30, 2011
 * Author: frank
 */

#include <iostream>
#include <stdexcept>

#include "FunctionTracker.h"

#define DEBUG

/*
 * a test class to check, if EnterExitMsg
 * does unwanted copying or given arguments
 */
class TestClass
{
public:
    TestClass()
    {};

    ~TestClass()
    {};

    TestClass(
        const TestClass & rhs)
    {
        std::cerr << "!!! TestClass copy c'tor invoked !!!" << std::endl;
    };
};

std::ostream &
operator<<(
    std::ostream & out,
    const TestClass & arg)
{
    out << "TestClass";
    return out;
}

int
ForthLevelProcedure(
    char const * const inp)
{
    int retVal = 4711;
    bool normalExit = false;
#ifdef DEBUG
    auto enterExitMsg = FunctionTracker<char const * const, int,
bool>::make(
        __FUNCTION__,
        InArg<char const * const>("inp", inp),
        OutArg<int>("retVal", retVal),
        OutArg<bool>("normalExit", normalExit)
        );
#endif

    throw std::runtime_error("hello");
    normalExit = true;
    return retVal;
}

int
ThirdLevelProcedure(
    int const & inp1,
    char const * const inp2,
    const TestClass & tc1,
    const TestClass & tc2)
{
    int retVal = 3;
    bool normalExit = 0;

#ifdef DEBUG
    auto enterExitMsg = FunctionTracker<int, char const * const,
TestClass, TestClass, int, bool>::make(
        __FUNCTION__,
        std::forward<InArg<int>>(InArg<int>("inp1", inp1)),
        std::forward<InArg<char const * const>>(InArg<char const *
const>("inp2", inp2)),
        std::forward<InArg<TestClass>>(InArg<TestClass>("tc1", tc1)),
        std::forward<InArg<TestClass>>(InArg<TestClass>("tc2", tc2)),
        std::forward<OutArg<int>>(OutArg<int>("retVal", retVal)),
        std::forward<OutArg<bool>>(OutArg<bool>("normalExit", normalExit)));
#endif

    std::cerr << "\thello, from ThirdLevelProcedure()" << std::endl;

    // check for throwing function called
    try {
        ForthLevelProcedure("calling ForthLevelProcedure()");
    }
    catch(...) {
        std::cerr << "!!! caught exception from
ForthLevelProcedure(...) !!!" << std::endl;
    }

    normalExit = true;
    return retVal;
}

int
SecondLevelProcedure(
    void)
{
    int retVal = 2;

#ifdef DEBUG
    auto enterExitMsg = FunctionTracker<int>::make(
        __FUNCTION__,
        std::forward<OutArg<int>>(OutArg<int>("retVal", retVal)));
#endif

    std::cerr << "\thello, from SecondLevelProcedure()" << std::endl;

    TestClass tc;
    ThirdLevelProcedure(5, "calling ThirdLevelProcedure()", tc,
TestClass());

    return retVal;
}

int
FirstLevelProcedure(
    char const * const inp1)
{
    int retVal = 1;

#ifdef DEBUG
    auto functionTracker = FunctionTracker<char const * const,
int>::make(
        __FUNCTION__,
        std::forward<InArg<char const * const>>(InArg<char const *
const>("inp1", inp1)),
        std::forward<OutArg<int>>(OutArg<int>("retVal", retVal)));
#endif

    std::cerr << "\thello, from FirstLevelProcedure()" << std::endl;

    SecondLevelProcedure();

    return retVal;
}

int
main(
    int argc,
    char ** argv)
{
    FirstLevelProcedure("calling FirstLevelProcedure()");
#if 0
    std::cerr << std::endl;

    SecondLevelProcedure();
#endif
    return 0;
}
-----------------------------------------------------------------------------------------------

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