exception.h

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// Copyright (c) 2018, Smart Projects Holdings Ltd
// All rights reserved.
// See LICENSE file for license details.

#ifndef _UGCS_VSM_EXCEPTION_H_
#define _UGCS_VSM_EXCEPTION_H_

#include <ugcs/vsm/defs.h>
#include <stdarg.h>
#include <string>

namespace ugcs {
namespace vsm {

class Exception: public std::exception {
public:
    struct Va_list_overload {
        // Workaround for http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60336
        char dummy;
    };

    struct Va_args_overload {
        // Workaround for http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60336
        char dummy;
    };

    Exception(): msg("<no message>") {}

    Exception(Va_args_overload, const char *msg, ...) __FORMAT(printf, 3, 4);

    Exception(Va_list_overload, const char *msg, va_list args) __FORMAT(printf, 3, 0);

    virtual
    ~Exception() noexcept
    {}

    virtual const char *
    what() const noexcept override
    {
        return msg.c_str();
    }

protected:
    std::string msg;

    void
    Create_msg(const char *msg, va_list args);
};

template <typename Dummy = void, typename TParam = int>
class Param_exception: public Exception {
public:
    TParam param;

    // @{
    Param_exception(Va_args_overload, const char *msg, ...) __FORMAT(printf, 3, 4)
    {
        va_list args;
        va_start(args, msg);
        Create_msg(msg, args);
        va_end(args);
    }

    Param_exception(Va_list_overload, const char *msg, va_list args) __FORMAT(printf, 3, 0)
    {
        Create_msg(msg, args);
    }

    Param_exception(Va_args_overload, const TParam &param, const char *msg, ...)
        __FORMAT(printf, 4, 5):
        param(param)
    {
        va_list args;
        va_start(args, msg);
        Create_msg(msg, args);
        va_end(args);
    }

    Param_exception(Va_list_overload, const TParam &param, const char *msg, va_list args)
        __FORMAT(printf, 4, 0):
        param(param)
    {
        Create_msg(msg, args);
    }
    // @}
};

template <class Base_exception, typename Dummy = void>
class Derived_exception: public Base_exception {
public:
    template <typename... Args>
    Derived_exception(Args &&... args):
        Base_exception(std::forward<Args>(args)...)
    {}
};

#ifdef DEBUG

#define VSM_EXCEPTION(__exc_class, __msg, ...) \
    throw __exc_class(__exc_class::Va_args_overload(), "[%s:%d] " __msg, __FILE__, __LINE__, ## __VA_ARGS__)

#define VSM_PARAM_EXCEPTION(__exc_class, __param, __msg, ...) \
    throw __exc_class(__exc_class::Va_args_overload(), __param, "[%s:%d] " __msg, __FILE__, __LINE__, ## __VA_ARGS__)

#else /* DEBUG */

#define VSM_EXCEPTION(__exc_class, __msg, ...) \
    /* Dummy format argument is added to avoid GCC 4.8.1 bug related to printf attribute. */ \
    throw __exc_class(__exc_class::Va_args_overload(), "%s" __msg, "", ## __VA_ARGS__)

#define VSM_PARAM_EXCEPTION(__exc_class, __param, __msg, ...) \
    /* Dummy format argument is added to avoid GCC 4.8.1 bug related to printf attribute. */ \
    throw __exc_class(__exc_class::Va_args_overload(), __param, "%s" __msg, "", ## __VA_ARGS__)

#endif /* DEBUG */

#define VSM_SYS_EXCEPTION(__msg, ...) do { \
    std::string sys_msg = ugcs::vsm::Log::Get_system_error(); \
    VSM_EXCEPTION(ugcs::vsm::System_exception, __msg ": %s", ## __VA_ARGS__, sys_msg.c_str()); \
} while (false)

#define VSM_DEFINE_EXCEPTION(__exc_class, ...) \
    struct __exc_class ## _dummy_struct {}; \
    typedef ugcs::vsm::Param_exception<__exc_class ## _dummy_struct, ## __VA_ARGS__> __exc_class

#define VSM_DEFINE_DERIVED_EXCEPTION(__base_class, __exc_class) \
 \
    struct __exc_class ## _dummy_struct {}; \
 \
    typedef ugcs::vsm::Derived_exception<__base_class, __exc_class ## _dummy_struct> __exc_class


/* Some common exceptions below. */

VSM_DEFINE_EXCEPTION(Debug_assert_exception);
VSM_DEFINE_EXCEPTION(Nullptr_exception);
VSM_DEFINE_EXCEPTION(Invalid_param_exception);
VSM_DEFINE_EXCEPTION(Invalid_op_exception);
VSM_DEFINE_EXCEPTION(Internal_error_exception);
VSM_DEFINE_EXCEPTION(System_exception);

} /* namespace vsm */
} /* namespace ugcs */

#endif /* _UGCS_VSM_EXCEPTION_H_ */