cyg_ass.h

该工程是从ecos嵌入式系统下移植过来的一个小型的fat16文件系统

#ifdef CYGDBG_INFRA_DEBUG_LOOP_INVARIANTS
# define CYG_LOOP_INVARIANT( _bool_ , _msg_ ) CYG_ASSERT( _bool_, _msg_ )
# define CYG_LOOP_INVARIANTC( _bool_ ) \
    CYG_ASSERT( _bool_, "loop invariant " #_bool_ )
#else
# define CYG_LOOP_INVARIANT( _bool_ , _msg_ ) CYG_EMPTY_STATEMENT
# define CYG_LOOP_INVARIANTC( _bool_ )        CYG_EMPTY_STATEMENT
#endif

#ifdef __cplusplus

// All variants of _CLASS
# define CYG_PRECONDITION_CLASS( _pobj_, _msg_ )  \
    CYG_PRECONDITION( ((0 != (_pobj_)) &&         \
                       (_pobj_)->check_this(CYG_ASSERT_CLASS_ZEAL)), _msg_)

# define CYG_PRECONDITION_CLASSC( _pobj_ )        \
    CYG_PRECONDITION_CLASS( (_pobj_),             \
       "precondition, class pointer (" #_pobj_ ") is valid" )
    
# define CYG_POSTCONDITION_CLASS( _pobj_, _msg_ ) \
    CYG_POSTCONDITION( ((0 != (_pobj_)) &&        \
                        (_pobj_)->check_this(CYG_ASSERT_CLASS_ZEAL)), _msg_)

# define CYG_POSTCONDITION_CLASSC( _pobj_ )       \
    CYG_POSTCONDITION_CLASS( (_pobj_),            \
       "postcondition, class pointer (" #_pobj_ ") is valid" )

# define CYG_LOOP_INVARIANT_CLASS( _pobj_, _msg_) \
    CYG_LOOP_INVARIANT( ((0 != (_pobj_)) &&       \
                         (_pobj_)->check_this(CYG_ASSERT_CLASS_ZEAL)), _msg_)
        
# define CYG_LOOP_INVARIANT_CLASSC( _pobj_ )      \
    CYG_LOOP_INVARIANT_CLASS( (_pobj_),           \
       "loop invariant, class pointer (" #_pobj_ ") is valid" )

// All variants of _CLASSO
# define CYG_PRECONDITION_CLASSO( _obj_, _msg_ )  \
    CYG_PRECONDITION( (_obj_).check_this(CYG_ASSERT_CLASS_ZEAL), _msg_)
    
# define CYG_PRECONDITION_CLASSOC( _obj_ )        \
    CYG_PRECONDITION_CLASSO( (_obj_),             \
        "precondition, object (" #_obj_ ") is valid" )

# define CYG_POSTCONDITION_CLASSO( _obj_, _msg_ ) \
    CYG_POSTCONDITION( (_obj_).check_this(CYG_ASSERT_CLASS_ZEAL), _msg_)
    
# define CYG_POSTCONDITION_CLASSOC( _obj_ )       \
    CYG_POSTCONDITION_CLASSO( (_obj_),            \
       "postcondition, object (" #_obj_ ") is valid" )
                             
# define CYG_LOOP_INVARIANT_CLASSO( _obj_, _msg_) \
    CYG_LOOP_INVARIANT( (_obj_).check_this(CYG_ASSERT_CLASS_ZEAL), _msg_)

# define CYG_LOOP_INVARIANT_CLASSOC( _obj_ )      \
    CYG_LOOP_INVARIANT_CLASSO( (_obj_),           \
       "loop invariant, object (" #_obj_ ") is valid" )

// All variants of _ZERO_OR_CLASS
# define CYG_PRECONDITION_ZERO_OR_CLASS( _pobj_, _msg_ )  \
    CYG_PRECONDITION( ((0 == (_pobj_)) ||                 \
                       (_pobj_)->check_this(CYG_ASSERT_CLASS_ZEAL)), _msg_)
    
# define CYG_PRECONDITION_ZERO_OR_CLASSC( _pobj_ )        \
    CYG_PRECONDITION_ZERO_OR_CLASS( (_pobj_),             \
       "precondition, class pointer (" #_pobj_ ") is zero or valid" )
    
# define CYG_POSTCONDITION_ZERO_OR_CLASS( _pobj_, _msg_ ) \
    CYG_POSTCONDITION( ((0 == (_pobj_)) ||                \
                        (_pobj_)->check_this(CYG_ASSERT_CLASS_ZEAL)), _msg_)

# define CYG_POSTCONDITION_ZERO_OR_CLASSC( _pobj_ )       \
    CYG_POSTCONDITION_ZERO_OR_CLASS( (_pobj_),            \
       "postcondition, class pointer (" #_pobj_ ") is zero or valid" )
                             
# define CYG_LOOP_INVARIANT_ZERO_OR_CLASS( _pobj_, _msg_) \
    CYG_LOOP_INVARIANT( ((0 == (_pobj_)) ||               \
                         (_pobj_)->check_this(CYG_ASSERT_CLASS_ZEAL)), _msg_)
        
# define CYG_LOOP_INVARIANT_ZERO_OR_CLASSC( _pobj_ )      \
    CYG_LOOP_INVARIANT_ZERO_OR_CLASS( (_pobj_),           \
       "loop invariant, class pointer (" #_pobj_ ") is zero or valid" )

// All variants of _THIS
# define CYG_PRECONDITION_THIS( _msg_ )  \
    CYG_PRECONDITION( this->check_this(CYG_ASSERT_CLASS_ZEAL), _msg_)
    
# define CYG_PRECONDITION_THISC()        \
    CYG_PRECONDITION_THIS( "precondition, \"this\"  is valid" )
    
# define CYG_POSTCONDITION_THIS( _msg_ ) \
    CYG_POSTCONDITION( this->check_this(CYG_ASSERT_CLASS_ZEAL), _msg_)
    
# define CYG_POSTCONDITION_THISC()       \
    CYG_POSTCONDITION_THIS( "postcondition, \"this\" is valid" )
                             
# define CYG_LOOP_INVARIANT_THIS( _msg_) \
    CYG_LOOP_INVARIANT( this->check_this(CYG_ASSERT_CLASS_ZEAL), _msg_)
        
# define CYG_LOOP_INVARIANT_THISC()      \
    CYG_LOOP_INVARIANT_THIS( "loop invariant, \"this\" is valid" )

#endif // __cplusplus

// -------------------------------------------------------------------------
// Invariants. These are a bit more interesting. The ordinary invariants
// take an arbitrary boolean expression, and C++ does not provide any way
// of evaluating this expression automatically on entry and exit - any
// attempt to use local objects leads to trying to evaluate the expression
// when it is not in scope. This problem does not arise with objects.
//
// For C++ objects it is possible to do a bit better. A template can be
// used to create a local object whose constructor will validate the
// target object and whose destructor will validate the target object
// again. Unfortunately it is necessary to pass the type as well as
// the object: typeof() is a gcc extension, and RTTI's typeid facility
// would provide the derived class and not what we actually want.            

#ifdef CYGDBG_INFRA_DEBUG_INVARIANTS    

# define CYG_INVARIANT( _bool_, _msg_ ) \
        CYG_MACRO_START                 \
        if ( ! ( _bool_ ) )             \
            CYG_ASSERT_DOCALL( _msg_ ); \
        CYG_MACRO_END

# define CYG_INVARIANTC( _bool_ )       \
        CYG_MACRO_START                 \
        if ( ! ( _bool_ ) )             \
            CYG_ASSERT_DOCALL( "invariant (" #_bool_ ")" ); \
        CYG_MACRO_END

# ifdef __cplusplus
// NOTE: if the compiler does not manage to inline the appropriate
// template functions then the impact on code size and performance becomes
// rather large. But there are significant performance overheads anyway
// simply because of the call to check_this()...            
//
template<class X> class __CygInvariantObject {

    const X*  rep;

  private:
    // Prevent access to the default constructors.
    __CygInvariantObject() { }
    __CygInvariantObject( const __CygInvariantObject&  arg ) { }
    __CygInvariantObject & operator=( const __CygInvariantObject & arg) { return *this; }
    
  public:
    __CygInvariantObject( X* arg, const char* msg ) : rep(arg) {
        if ( !rep->check_this( CYG_ASSERT_CLASS_ZEAL ) )
            CYG_ASSERT_DOCALL( msg );
    }
    __CygInvariantObject( X& arg, const char* msg ) : rep(&arg) {
        if ( !rep->check_this( CYG_ASSERT_CLASS_ZEAL ) )
            CYG_ASSERT_DOCALL( msg );
    }
    __CygInvariantObject( const X* arg, const char* msg ) : rep(arg) {
        if ( !rep->check_this( CYG_ASSERT_CLASS_ZEAL ) )
            CYG_ASSERT_DOCALL( msg );
    }
    __CygInvariantObject( const X& arg, const char* msg ) : rep(&arg) {
        if ( !rep->check_this( CYG_ASSERT_CLASS_ZEAL ) )
            CYG_ASSERT_DOCALL( msg );
    }
    ~__CygInvariantObject( ) {
        if ( !rep->check_this( CYG_ASSERT_CLASS_ZEAL ) )
            CYG_ASSERT_DOCALL( "invariant, object valid on exit" );
        rep = 0;
    };
};

//
// These macros provide sensible concatenation facilities at
// the C preprocessor level, getting around complications in the
// macro expansion rules related to __LINE__ and __FILE__.

# define __CYG_INVARIANT_CLASSNAME_AUX( a, b) a ## b
# define __CYG_INVARIANT_CLASSNAME( a, b ) \
              __CYG_INVARIANT_CLASSNAME_AUX( a, b )


// These macro definitions do not use CYG_MACRO_START because
// I do not want the scope of the local objects to get confused.
//
// The first line of the macro expansion specifies the type of
// the local object being created. The second line invents a
// name for this object. The third line provides command-line
// arguments.    

# define CYG_INVARIANT_CLASS( _type_, _pobj_, _msg_ )          \
     __CygInvariantObject<_type_>                              \
     __CYG_INVARIANT_CLASSNAME( __invariant_class_, __LINE__ ) \
              ( _pobj_, _msg_ )

# define CYG_INVARIANT_CLASSC( _type_, _pobj_ )                \
     __CygInvariantObject<_type_>                              \
     __CYG_INVARIANT_CLASSNAME( __invariant_class_, __LINE__ ) \
              ( _pobj_, "invariant, class pointer (" #_pobj_ ") is valid" )
         
# define CYG_INVARIANT_CLASSO( _type_, _obj_, _msg_ )          \
     __CygInvariantObject<_type_>                              \
     __CYG_INVARIANT_CLASSNAME( __invariant_class_, __LINE__ ) \
              ( _obj_, _msg_ )

# define CYG_INVARIANT_CLASSOC( _type_, _obj_ )                \
     __CygInvariantObject<_type_>                              \
     __CYG_INVARIANT_CLASSNAME( __invariant_class_, __LINE__ ) \
              ( _obj_, "invariant, object (" #_obj_ ") is valid" )

# define CYG_INVARIANT_THIS( _type_, _msg_ )                   \
     __CygInvariantObject<_type_>                              \
     __CYG_INVARIANT_CLASSNAME( __invariant_class_, __LINE__ ) \
              ( this, _msg_ )
         
# define CYG_INVARIANT_THISC( _type_ )                         \
     __CygInvariantObject<_type_>                              \
     __CYG_INVARIANT_CLASSNAME( __invariant_class_, __LINE__ ) \
              ( this, "invariant, \"this\" is valid" )

# endif // __cplusplus

#else  // !CYGDBG_INFRA_DEBUG_INVARIANTS

# define CYG_INVARIANT( _bool_, _msg_ ) CYG_EMPTY_STATEMENT
# define CYG_INVARIANTC( _bool_ )       CYG_EMPTY_STATEMENT

# ifdef __cplusplus

#  define CYG_INVARIANT_CLASS( _type_, _pobj_, _msg_ )
#  define CYG_INVARIANT_CLASSC( _type_, _pobj_ )
#  define CYG_INVARIANT_CLASSO( _type_, _obj_, _msg_ )
#  define CYG_INVARIANT_CLASSOC( _type_, _obj_ )
#  define CYG_INVARIANT_THIS( _type_, _msg_ )
#  define CYG_INVARIANT_THISC( _type_ )

# endif
    
#endif // CYGDBG_INFRA_DEBUG_INVARIANTS

// -------------------------------------------------------------------------
// Compile time failure; like #error but in a macro so we can use it in
// other definitions.
//
// Usage:
// #define new CYG_COMPILETIMEFAIL( "Do NOT use new!")

#define CYG_COMPILETIMEFAIL( _msg_ ) !!!-- _msg_ --!!!


// -------------------------------------------------------------------------
// The host-side implementation of the infrastructure provides a number
// of additional functions that allow applications to provide their own
// implementation of cyg_assert_fail(). This is not strictly necessary
// since the presence of cyg_assert_fail() in the application would
// override the one in the library anyway, but it is useful to make
// certain functionality more readily available.
//
// These declarations are only available if the symbol
// CYG_DECLARE_HOST_ASSERTION_SUPPORT is defined.
#ifdef CYG_DECLARE_HOST_ASSERTION_SUPPORT

// The default assertion handler writes its output to a file and
// if possible a suitable message to stdout. It is possible to
// install an alternative handler. If this alternative returns false
// then the default handler will be invoked instead, otherwise the
// application will exit.
externC void cyg_assert_install_failure_handler(
                bool (*)(const char* /* psz_func */,
                         const char* /* psz_file */,
                         cyg_uint32  /* linenum */,
                         const char* /* psz_msg */) );

// Register a callback that should get invoked as part of handling an
// assertion failure and that will typically produce some additional
// output. For example the trace code will install a callback to output
// trace information.
//
// The first argument is a string identifying the callback. The second
// argument is a function pointer for the callback itself, whose
// argument is another function that can be invoked for output.
externC void cyg_assert_install_failure_callback(
                const char* /* name */,
                void (*)( void (*)(const char*) ));

// This function can be called by assert failure handlers to invoke
// the installed callbacks. The three arguments are function pointers
// that get invoked prior to callback invocation, by the callback itself,
// and after each callback. In the first case the argument will be the
// callback name.
externC void cyg_assert_failure_invoke_callbacks(
                void (*)(const char* /* name */),
                void (*)(const char* /* callback data */ ),
                void (*)(void) );

// This function is intended to be called from inside gdb instead of
// cyg_assert_fail(),, without the need to specify a filename or
// anything else.
externC void cyg_assert_quickfail(void);

#endif // CYG_DECLARE_HOST_ASSERTION_SUPPORT
    
// -------------------------------------------------------------------------

#endif // CYGONCE_INFRA_CYG_ASS_H multiple inclusion protection
// EOF cyg_ass.h