This group contains basic macros and defines to give access to compiler-specific features. More...

Files
file	basedefs.h
	This header file provides basic definitions used by the API and the implementation.

Macros
#define	RTEMS_CONCAT(_x, _y) _x##_y
	Concatenates _x and _y without expanding. More...

#define	RTEMS_TYPEOF_REFX(_level, _target) __typeof__(_level(union { int z; __typeof__(_target) x; }){0}.x)
	Returns the type of a pointer reference of the specified level to the specified type. More...

#define	RTEMS_STRING(_x) #_x
	Stringifies _x without expanding. More...

#define	RTEMS_XCONCAT(_x, _y) RTEMS_CONCAT( _x, _y )
	Concatenates expansion of _x and expansion of _y. More...

#define	RTEMS_EXPAND(_token) _token
	Helper macro to perform a macro expansion on the specified token. More...

#define	RTEMS_DEPRECATED __attribute__((__deprecated__))
	Instructs the compiler in a declaration to issue a warning whenever a variable, function, or type using this declaration will be used.

#define	RTEMS_NO_RETURN __attribute__((__noreturn__))
	Tells the compiler in a function declaration that this function does not return.

#define	RTEMS_PACKED __attribute__((__packed__))
	Instructs the compiler in a type definition to place members of a structure or union so that the memory required is minimized.

#define	RTEMS_PURE __attribute__((__pure__))
	Tells the compiler in a function declaration that this function has no effect except the return value and that the return value depends only on the value of parameters and/or global variables.

#define	RTEMS_USED __attribute__((__used__))
	Tells the compiler that a specific variable or function is used.

#define	RTEMS_DEQUALIFY_DEPTHX(_ptr_level, _type, _var)
	Performs a type cast which removes qualifiers without warnings to the specified type for the specified variable. More...

#define	RTEMS_XSTRING(_x) RTEMS_STRING( _x )
	Stringifies the expansion of _x. More...

#define	RTEMS_SYMBOL_NAME(_name) RTEMS_EXPAND(_name)
	Constructs a symbol name. More...

#define	RTEMS_ALIAS(_target) __attribute__((__alias__(#_target)))
	Instructs the compiler to generate an alias to the specified target function. More...

#define	RTEMS_ALIGN_DOWN(_value, _alignment) ( ( _value ) & ~( ( _alignment ) - 1 ) )
	Returns the specified value aligned down to the specified alignment. More...

#define	RTEMS_ALIGN_UP(_value, _alignment) ( ( ( _value ) + ( _alignment ) - 1 ) & ~( ( _alignment ) - 1 ) )
	Returns the specified value aligned up to the specified alignment. More...

#define	RTEMS_ALIGNED(_alignment) __attribute__((__aligned__(_alignment)))
	Instructs the compiler in a declaration or definition to enforce the specified alignment. More...

#define	RTEMS_ALLOC_ALIGN(_index) __attribute__((__alloc_align__(_index)))
	Tells the compiler in a declaration that the memory allocation alignment parameter of this function is similar to aligned_alloc(). More...

#define	RTEMS_ALLOC_SIZE(_index) __attribute__((__alloc_size__(_index)))
	Tells the compiler in a declaration that the memory allocation size parameter of this function is similar to malloc(). More...

#define	RTEMS_ALLOC_SIZE_2(_count_index, _size_index) __attribute__((__alloc_size__(_count_index, _size_index)))
	Tells the compiler in a declaration that the memory allocation item count and item size parameter of this function is similar to calloc(). More...

#define	RTEMS_ARRAY_SIZE(_array) (sizeof(_array) / sizeof((_array)[0]))
	Returns the element count of the specified array. More...

#define	RTEMS_COMPILER_DEPRECATED_ATTRIBUTE RTEMS_DEPRECATED
	Provided for backward compatibility.

#define	RTEMS_COMPILER_MEMORY_BARRIER() __asm__ volatile( "" ::: "memory" )
	This macro forbids the compiler to reorder read and write commands around it.

#define	RTEMS_COMPILER_NO_RETURN_ATTRIBUTE RTEMS_NO_RETURN
	Provided for backward compatibility.

#define	RTEMS_COMPILER_PACKED_ATTRIBUTE RTEMS_PACKED
	Provided for backward compatibility.

#define	RTEMS_COMPILER_PURE_ATTRIBUTE RTEMS_PURE
	Provided for backward compatibility.

#define	RTEMS_COMPILER_USED_ATTRIBUTE RTEMS_USED
	Provided for backward compatibility.

#define	RTEMS_CONST __attribute__((__const__))
	Tells the compiler in a function declaration that this function has no effect except the return value and that the return value depends only on the value of parameters.

#define	RTEMS_CONTAINER_OF(_m, _type, _member_name) ( (_type *) ( (uintptr_t) ( _m ) - offsetof( _type, _member_name ) ) )
	Returns the pointer to the container of a specified member pointer. More...

#define	RTEMS_DECLARE_GLOBAL_SYMBOL(_name) extern char _name[]
	Declares a global symbol with the specified name. More...

#define	RTEMS_DECONST(_type, _var) RTEMS_DEQUALIFY_DEPTHX(*, _type, _var)
	Performs a type cast which removes const qualifiers without warnings to the specified type for the specified pointer variable. More...

#define	RTEMS_DEFINE_GLOBAL_SYMBOL(_name, _value)
	Defines a global symbol with the specified name and value. More...

#define	RTEMS_DEQUALIFY(_type, _var) RTEMS_DEQUALIFY_DEPTHX(*, _type, _var)
	Performs a type cast which removes all qualifiers without warnings to the specified type for the specified pointer variable. More...

#define	RTEMS_DEVOLATILE(_type, _var) RTEMS_DEQUALIFY_DEPTHX(*, _type, _var)
	Performs a type cast which removes volatile qualifiers without warnings to the specified type for the specified pointer variable. More...

#define	FALSE 0
	If FALSE is undefined, then FALSE is defined to 0.

#define	RTEMS_HAVE_MEMBER_SAME_TYPE(_t_lhs, _m_lhs, _t_rhs, _m_rhs)
	Evaluates to true if the specified members of two types have compatible types, otherwise to false. More...

#define	RTEMS_INLINE_ROUTINE static __inline__
	Gives a hint to the compiler in a function declaration to inline this function.

#define	RTEMS_MALLOCLIKE __attribute__((__malloc__))
	Tells the compiler in a declaration that this function is a memory allocation function similar to malloc().

#define	RTEMS_NO_INLINE __attribute__((__noinline__))
	Instructs the compiler in a function declaration to not inline this function.

#define	RTEMS_OBFUSCATE_VARIABLE(_var) __asm__( "" : "+r" ( _var ) )
	Obfuscates the variable so that the compiler cannot perform optimizations based on the variable value. More...

#define	RTEMS_PREDICT_FALSE(_exp) __builtin_expect( ( _exp ), 0 )
	Returns the value of the specified integral expression and tells the compiler that the predicted value is false (1). More...

#define	RTEMS_PREDICT_TRUE(_exp) __builtin_expect( ( _exp ), 1 )
	Returns the value of the specified integral expression and tells the compiler that the predicted value is true (1). More...

#define	RTEMS_PRINTFLIKE(_format_pos, _ap_pos) __attribute__((__format__(__printf__, _format_pos, _ap_pos)))
	Tells the compiler in a declaration that this function expects printf()-like arguments. More...

#define	RTEMS_RETURN_ADDRESS() __builtin_return_address(0)
	Returns the return address of the current function. More...

#define	RTEMS_SECTION(_section) __attribute__((__section__(_section)))
	Instructs the compiler to place a specific variable or function in the specified section. More...

#define	RTEMS_STATIC_ASSERT(_cond, _msg)
	Asserts at compile time that the specified condition is satisfied. More...

#define	TRUE 1
	If TRUE is undefined, then TRUE is defined to 1.

#define	RTEMS_UNUSED __attribute__((__unused__))
	Tells the compiler that a specific variable or function is deliberately unused.

#define	RTEMS_WARN_UNUSED_RESULT __attribute__((__warn_unused_result__))
	Tells the compiler in a declaration that the result of this function should be used.

#define	RTEMS_WEAK __attribute__((__weak__))
	Tells the compiler in a function definition that this function should be weak. More...

#define	RTEMS_WEAK_ALIAS(_target) __attribute__((__weak__, __alias__(#_target)))
	Instructs the compiler to generate a weak alias to the specified target function. More...

#define	RTEMS_ZERO_LENGTH_ARRAY 0
	This is a constant to declare zero-length arrays. More...

Detailed Description

This group contains basic macros and defines to give access to compiler-specific features.

Macro Definition Documentation

◆ RTEMS_ALIAS

#define RTEMS_ALIAS ( _target ) __attribute__((__alias__(#_target)))

Instructs the compiler to generate an alias to the specified target function.

Parameters

_target is the target function name.

Definition at line 335 of file basedefs.h.

◆ RTEMS_ALIGN_DOWN

#define RTEMS_ALIGN_DOWN	(	_value,
		_alignment
	)	( ( _value ) & ~( ( _alignment ) - 1 ) )

Returns the specified value aligned down to the specified alignment.

Parameters

_value	is the value to align down.
_alignment	is the desired alignment in bytes. The alignment shall be a power of two, otherwise the returned value is undefined. The alignment parameter is evaluated twice.

Returns: The specified value aligned down to the specified alignment is returned.

Definition at line 356 of file basedefs.h.

◆ RTEMS_ALIGN_UP

#define RTEMS_ALIGN_UP	(	_value,
		_alignment
	)	( ( ( _value ) + ( _alignment ) - 1 ) & ~( ( _alignment ) - 1 ) )

Returns the specified value aligned up to the specified alignment.

Parameters

_value	is the value to align up.
_alignment	is the desired alignment in bytes. The alignment shall be a power of two, otherwise the returned value is undefined. The alignment parameter is evaluated twice.

Returns: The specified value aligned up to the specified alignment is returned.

Definition at line 375 of file basedefs.h.

◆ RTEMS_ALIGNED

#define RTEMS_ALIGNED ( _alignment ) __attribute__((__aligned__(_alignment)))

Instructs the compiler in a declaration or definition to enforce the specified alignment.

Parameters

_alignment is the desired alignment in bytes.

Definition at line 389 of file basedefs.h.

◆ RTEMS_ALLOC_ALIGN

#define RTEMS_ALLOC_ALIGN ( _index ) __attribute__((__alloc_align__(_index)))

Tells the compiler in a declaration that the memory allocation alignment parameter of this function is similar to aligned_alloc().

Parameters

_index is the allocation alignment parameter index (starting with one).

Definition at line 406 of file basedefs.h.

◆ RTEMS_ALLOC_SIZE

#define RTEMS_ALLOC_SIZE ( _index ) __attribute__((__alloc_size__(_index)))

Tells the compiler in a declaration that the memory allocation size parameter of this function is similar to malloc().

Parameters

_index is the allocation size parameter index (starting with one).

Definition at line 422 of file basedefs.h.

◆ RTEMS_ALLOC_SIZE_2

#define RTEMS_ALLOC_SIZE_2	(	_count_index,
		_size_index
	)	__attribute__((__alloc_size__(_count_index, _size_index)))

Tells the compiler in a declaration that the memory allocation item count and item size parameter of this function is similar to calloc().

Parameters

_count_index	is the allocation item count parameter index (starting with one).
_size_index	is the allocation item size parameter index (starting with one).

Definition at line 442 of file basedefs.h.

◆ RTEMS_ARRAY_SIZE

#define RTEMS_ARRAY_SIZE ( _array ) (sizeof(_array) / sizeof((_array)[0]))

Returns the element count of the specified array.

Parameters

_array is the name of the array.

Returns: The element count of the specified array.

Definition at line 459 of file basedefs.h.

◆ RTEMS_CONCAT

#define RTEMS_CONCAT	(	_x,
		_y
	)	_x##_y

Concatenates _x and _y without expanding.

Parameters

_x	is the left hand side token of the concatenation.
_y	is the right hand side token of the concatenation.

Returns: The concatenation of the tokens _x and _y.

Definition at line 105 of file basedefs.h.

◆ RTEMS_CONTAINER_OF

#define RTEMS_CONTAINER_OF	(	_m,
		_type,
		_member_name
	)	( (_type *) ( (uintptr_t) ( _m ) - offsetof( _type, _member_name ) ) )

Returns the pointer to the container of a specified member pointer.

Parameters

_m	is the pointer to a member of the container.
_type	is the type of the container.
_member_name	is the designator name of the container member.

Returns: Returns the pointer to the container of a specified member pointer.

Definition at line 550 of file basedefs.h.

◆ RTEMS_DECLARE_GLOBAL_SYMBOL

#define RTEMS_DECLARE_GLOBAL_SYMBOL ( _name ) extern char _name[]

Declares a global symbol with the specified name.

This macro must be placed at file scope.

Parameters

_name is the name of the global symbol. It shall be a valid designator.

Definition at line 565 of file basedefs.h.

◆ RTEMS_DECONST

#define RTEMS_DECONST	(	_type,
		_var
	)	RTEMS_DEQUALIFY_DEPTHX(*, _type, _var)

Performs a type cast which removes const qualifiers without warnings to the specified type for the specified pointer variable.

Parameters

_type	is the target type of the cast.
_var	is the pointer variable.

Definition at line 579 of file basedefs.h.

◆ RTEMS_DEFINE_GLOBAL_SYMBOL

#define RTEMS_DEFINE_GLOBAL_SYMBOL	(	_name,
		_value
	)

Defines a global symbol with the specified name and value.

This macro shall be placed at file scope.

Parameters

_name	is the user defined name of the symbol. The name shall be a valid designator. On the name a macro expansion is performed and afterwards it is stringified.
_value	is the value of the symbol. On the value a macro expansion is performed and afterwards it is stringified. It shall expand to an integer expression understood by the assembler.

Definition at line 606 of file basedefs.h.

◆ RTEMS_DEQUALIFY

#define RTEMS_DEQUALIFY	(	_type,
		_var
	)	RTEMS_DEQUALIFY_DEPTHX(*, _type, _var)

Performs a type cast which removes all qualifiers without warnings to the specified type for the specified pointer variable.

Parameters

_type	is the target type of the cast.
_var	is the pointer variable.

Definition at line 621 of file basedefs.h.

◆ RTEMS_DEQUALIFY_DEPTHX

#define RTEMS_DEQUALIFY_DEPTHX	(	_ptr_level,
		_type,
		_var
	)

Value:

__builtin_choose_expr(__builtin_types_compatible_p( \
        RTEMS_TYPEOF_REFX(_ptr_level, _var), \
        RTEMS_TYPEOF_REFX(_ptr_level, _type) \
      ) || __builtin_types_compatible_p(_type, void *), \
    (_type)(_var), \
    RTEMS_DEQUALIFY_types_not_compatible())

Performs a type cast which removes qualifiers without warnings to the specified type for the specified variable.

Parameters

_ptr_level	is the pointer indirection level expressed in *.
_type	is the target type of the cast.
_var	is the variable.

Definition at line 272 of file basedefs.h.

◆ RTEMS_DEVOLATILE

#define RTEMS_DEVOLATILE	(	_type,
		_var
	)	RTEMS_DEQUALIFY_DEPTHX(*, _type, _var)

Performs a type cast which removes volatile qualifiers without warnings to the specified type for the specified pointer variable.

Parameters

_type	is the target type of the cast.
_var	is the pointer variable.

Definition at line 635 of file basedefs.h.

◆ RTEMS_EXPAND

#define RTEMS_EXPAND ( _token ) _token

Helper macro to perform a macro expansion on the specified token.

Parameters

_token is the token to expand.

Definition at line 182 of file basedefs.h.

◆ RTEMS_HAVE_MEMBER_SAME_TYPE

#define RTEMS_HAVE_MEMBER_SAME_TYPE	(	_t_lhs,
		_m_lhs,
		_t_rhs,
		_m_rhs
	)

Value:

__builtin_types_compatible_p( \
      __typeof__( ( (_t_lhs *) 0 )->_m_lhs ), \
      __typeof__( ( (_t_rhs *) 0 )->_m_rhs ) \
    )

Evaluates to true if the specified members of two types have compatible types, otherwise to false.

Parameters

_t_lhs	is the left hand side type.
_m_lhs	is the left hand side member.
_t_rhs	is the right hand side type.
_m_rhs	is the right hand side member.

Definition at line 665 of file basedefs.h.

◆ RTEMS_OBFUSCATE_VARIABLE

#define RTEMS_OBFUSCATE_VARIABLE ( _var ) __asm__( "" : "+r" ( _var ) )

Obfuscates the variable so that the compiler cannot perform optimizations based on the variable value.

The variable must be simple enough to fit into a register.

Parameters

_var	is the variable to obfuscate.

Definition at line 729 of file basedefs.h.

◆ RTEMS_PREDICT_FALSE

#define RTEMS_PREDICT_FALSE ( _exp ) __builtin_expect( ( _exp ), 0 )

Returns the value of the specified integral expression and tells the compiler that the predicted value is false (1).

Parameters

_exp	is the expression.

Returns: The value of the expression.

Definition at line 747 of file basedefs.h.

◆ RTEMS_PREDICT_TRUE

#define RTEMS_PREDICT_TRUE ( _exp ) __builtin_expect( ( _exp ), 1 )

Returns the value of the specified integral expression and tells the compiler that the predicted value is true (1).

Parameters

_exp	is the expression.

Returns: The value of the expression.

Definition at line 765 of file basedefs.h.

◆ RTEMS_PRINTFLIKE

#define RTEMS_PRINTFLIKE	(	_format_pos,
		_ap_pos
	)	__attribute__((__format__(__printf__, _format_pos, _ap_pos)))

Tells the compiler in a declaration that this function expects printf()-like arguments.

Parameters

_format_pos	is the position of the format parameter index (starting with one).
_ap_pos	is the position of the argument pointer parameter index (starting with one).

Definition at line 785 of file basedefs.h.

◆ RTEMS_RETURN_ADDRESS

#define RTEMS_RETURN_ADDRESS ( ) __builtin_return_address(0)

Returns the return address of the current function.

Returns: The return address of the current function.

Definition at line 801 of file basedefs.h.

◆ RTEMS_SECTION

#define RTEMS_SECTION ( _section ) __attribute__((__section__(_section)))

Instructs the compiler to place a specific variable or function in the specified section.

Parameters

_section is the section name as a string.

Definition at line 817 of file basedefs.h.

◆ RTEMS_STATIC_ASSERT

#define RTEMS_STATIC_ASSERT	(	_cond,
		_msg
	)

Value:

struct rtems_static_assert_ ## _msg \

{ int rtems_static_assert_ ## _msg : (_cond) ? 1 : -1; }

Asserts at compile time that the specified condition is satisfied.

Parameters

_cond	is the condition this static assertion shall satisfy.
_msg	is the error message in case the static assertion fails.

Definition at line 838 of file basedefs.h.

◆ RTEMS_STRING

#define RTEMS_STRING ( _x ) #_x

Stringifies _x without expanding.

Parameters

_x	is the token to stringify.

Returns: The stringification of the token _x.

Definition at line 154 of file basedefs.h.

◆ RTEMS_SYMBOL_NAME

#define RTEMS_SYMBOL_NAME ( _name ) RTEMS_EXPAND(_name)

Constructs a symbol name.

Parameters

_name is the user defined name of the symbol. The name shall be a valid designator. On the name a macro expansion is performed.

Definition at line 310 of file basedefs.h.

◆ RTEMS_TYPEOF_REFX

#define RTEMS_TYPEOF_REFX	(	_level,
		_target
	)	__typeof__(_level(union { int z; __typeof__(_target) x; }){0}.x)

Returns the type of a pointer reference of the specified level to the specified type.

The reference type idea is based on libHX by Jan Engelhardt.

Parameters

_level	is the pointer indirection level expressed in *.
_target	is the reference target type.

Definition at line 137 of file basedefs.h.

◆ RTEMS_WEAK

#define RTEMS_WEAK __attribute__((__weak__))

Tells the compiler in a function definition that this function should be weak.

Use this attribute for function definitions. Do not use it for function declarations.

Definition at line 909 of file basedefs.h.

◆ RTEMS_WEAK_ALIAS

#define RTEMS_WEAK_ALIAS ( _target ) __attribute__((__weak__, __alias__(#_target)))

Instructs the compiler to generate a weak alias to the specified target function.

Parameters

_target is the target function name.

Definition at line 925 of file basedefs.h.

◆ RTEMS_XCONCAT

#define RTEMS_XCONCAT	(	_x,
		_y
	)	RTEMS_CONCAT( _x, _y )

Concatenates expansion of _x and expansion of _y.

Parameters

_x	is expanded first and then used as the left hand side token of the concatenation.
_y	is expanded first and then used as the right hand side token of the concatenation.

Returns: The concatenation of the expansions of tokens _x and _y.

Definition at line 171 of file basedefs.h.

◆ RTEMS_XSTRING

#define RTEMS_XSTRING ( _x ) RTEMS_STRING( _x )

Stringifies the expansion of _x.

Parameters

_x	is the token expand and stringify.

Returns: The stringification of the expansion of token _x.

Definition at line 295 of file basedefs.h.

◆ RTEMS_ZERO_LENGTH_ARRAY

#define RTEMS_ZERO_LENGTH_ARRAY 0

This is a constant to declare zero-length arrays.

Zero-length arrays are valid in C99 as flexible array members. C++11 does not allow flexible array members. Use the GNU extension which is also supported by other compilers.

Definition at line 945 of file basedefs.h.

Files

Macros

Detailed Description

Macro Definition Documentation

◆ RTEMS_ALIAS

◆ RTEMS_ALIGN_DOWN

◆ RTEMS_ALIGN_UP

◆ RTEMS_ALIGNED

◆ RTEMS_ALLOC_ALIGN

◆ RTEMS_ALLOC_SIZE

◆ RTEMS_ALLOC_SIZE_2

◆ RTEMS_ARRAY_SIZE

◆ RTEMS_CONCAT

◆ RTEMS_CONTAINER_OF

◆ RTEMS_DECLARE_GLOBAL_SYMBOL

◆ RTEMS_DECONST

◆ RTEMS_DEFINE_GLOBAL_SYMBOL

◆ RTEMS_DEQUALIFY

◆ RTEMS_DEQUALIFY_DEPTHX

◆ RTEMS_DEVOLATILE

◆ RTEMS_EXPAND

◆ RTEMS_HAVE_MEMBER_SAME_TYPE

◆ RTEMS_OBFUSCATE_VARIABLE

◆ RTEMS_PREDICT_FALSE

◆ RTEMS_PREDICT_TRUE

◆ RTEMS_PRINTFLIKE

◆ RTEMS_RETURN_ADDRESS

◆ RTEMS_SECTION

◆ RTEMS_STATIC_ASSERT

◆ RTEMS_STRING

◆ RTEMS_SYMBOL_NAME

◆ RTEMS_TYPEOF_REFX

◆ RTEMS_WEAK

◆ RTEMS_WEAK_ALIAS

◆ RTEMS_XCONCAT

◆ RTEMS_XSTRING

◆ RTEMS_ZERO_LENGTH_ARRAY