Basic Macros

L4 standard macros for header files, function definitions, and public APIs etc. More...

Collaboration diagram for Basic Macros:

Macros
#define	L4_INLINE
	L4 Inline function attribute.
#define	L4_ALWAYS_INLINE
	Always inline a function.
#define	__BEGIN_DECLS
	Start section with C types and functions.
#define	__END_DECLS
	End section with C types and functions.
#define	EXTERN_C_BEGIN
	Start section with C types and functions.
#define	EXTERN_C_END
	End section with C types and functions.
#define	EXTERN_C
	Mark C types and functions.
#define	L4_NOTHROW
	Mark a function declaration and definition as never throwing an exception.
#define	L4_EXPORT
	Attribute to mark functions, variables, and data types as being exported from a library.
#define	L4_HIDDEN
	Attribute to mark functions, variables, and data types as being explicitly hidden from users of a library.
#define	L4_CONSTEXPR
	Constexpr function attribute.
#define	L4_NORETURN
	Noreturn function attribute.
#define	L4_NOINSTRUMENT
	No instrumentation function attribute.
#define	L4_LIKELY(x)
	Expression is likely to execute.
#define	L4_UNLIKELY(x)
	Expression is unlikely to execute.
#define	L4_STICKY(x)
	Mark symbol sticky (even not there)
#define	L4_DEPRECATED(s)
	Mark symbol deprecated.
#define	L4_stringify_helper(x)
	stringify helper.
#define	L4_stringify(x)
	stringify.
#define	L4_CV
	Define calling convention.
#define	L4_CV
	Define calling convention.
#define	L4_CV
	Define calling convention.

Functions
unsigned long	l4_align_stack_for_direct_fncall (unsigned long stack)
	Specify the desired alignment of the stack pointer.
void	l4_barrier (void)
	Memory barrier.
void	l4_mb (void)
	Memory barrier.
void	l4_wmb (void)
	Write memory barrier.
L4_NORETURN void	l4_infinite_loop (void)
	Infinite loop.

Detailed Description

L4 standard macros for header files, function definitions, and public APIs etc.

Include File

#include <l4/sys/compiler.h> 

Macro Definition Documentation

L4_EXPORT

#define L4_EXPORT

Attribute to mark functions, variables, and data types as being exported from a library.

All data types, functions, and global variables that shall be exported from a library shall be marked with this attribute. The default may become to hide everything that is not marked as L4_EXPORT from the users of a library and provide the possibility for aggressive optimization of all those internal functionality of a library.

Usage:

class L4_EXPORT My_class
{
  ...
};
 
int L4_EXPORT function(void);
 
int L4_EXPORT global_data; // global data is not recommended

Definition at line 231 of file compiler.h.

L4_HIDDEN

#define L4_HIDDEN

Attribute to mark functions, variables, and data types as being explicitly hidden from users of a library.

This attribute is intended for functions, data, and data types that shall never be visible outside of a library. In particular, for shared libraries this may result in much faster code within the library and short linking times.

class L4_HIDDEN My_class
{
  ...
};
 
int L4_HIDDEN function(void);
 
int L4_HIDDEN global_data; // global data is not recommended

Definition at line 228 of file compiler.h.

L4_NOTHROW

#define L4_NOTHROW

Mark a function declaration and definition as never throwing an exception.

(Also for C code).

This macro shall be used to mark C and C++ functions that never throw any exception. Note that also C functions may throw exceptions according to the compilers ABI and shall be marked with L4_NOTHROW if they never do. In C++ this is equivalent to throw().

int foo() L4_NOTHROW;
...
int foo() L4_NOTHROW
{
  ...
  return result;
}

Definition at line 188 of file compiler.h.

Function Documentation

l4_align_stack_for_direct_fncall()

unsigned long l4_align_stack_for_direct_fncall ( unsigned long  stack )

inline

Specify the desired alignment of the stack pointer.

BIGGEST_ALIGNMENT provides the largest alignment ever used for any data type on the target machine. This is normally identical to desired stack alignment. Align stack pointer for directly invoked functions.

The stack needs to be aligned to L4_STACK_ALIGN for being able to access certain data on the stack. On x86/AMD64, a function call is performed using the 'call' instruction decrementing the stack pointer and writing the return address onto the stack. The called function considers this when adapting the stack pointer after function entry. If the called function was not invoked by a 'call' instruction, the stack pointer is actually off by a machine word leading to stack alignment issues when executing SSE instructions.

This function fixes the stack pointer for directly invoked functions. For architectures not automatically pushing the stack pointer during a function call, just enforce the L4_STACK_ALIGN alignment.

Definition at line 285 of file compiler.h.

l4_infinite_loop()

L4_NORETURN void l4_infinite_loop ( void  )

inline

Infinite loop.

Will never return. Use l4_sleep_forever() if at all possible.

Definition at line 359 of file compiler.h.

References l4_barrier().

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