BeRTOS
Data Structures | Defines | Typedefs
compiler.h File Reference

Additional support macros for compiler independance. More...

#include <cpu/detect.h>
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <sys/types.h>

Go to the source code of this file.

Data Structures

struct  Signal
 Signal structure. More...

Defines

#define PP_CAT(x, y)   PP_CAT__(x,y)
 Concatenate two different preprocessor tokens (allowing macros to expand)
#define PP_STRINGIZE(x)   PP_STRINGIZE__(x)
 String-ize a token (allowing macros to expand)
#define COMPILER_VARIADIC_MACROS   1
 usage:
#define COMPILER_TYPEOF   1
 Support for dynamic type identification.
#define COMPILER_STATEMENT_EXPRESSIONS   1
 Support for statement expressions.
#define MEMORY_BARRIER   asm volatile ("" : : : "memory")
 Force compiler to reload context variable.
#define offsetof(s, m)   (size_t)&(((s *)0)->m)
 Return the byte offset of the member m in struct s.
#define countof(a)
 Count the number of elements in the static array a.
#define alignof(type)   offsetof(struct { char c; type member; }, member)
 Return the alignment in memory of a generic data type.
#define containerof(ptr, type, member)
 Cast a member of a structure out to the containing structure.
#define STATIC_ASSERT(condition)   UNUSED_VAR(extern char, STATIC_ASSERTION_FAILED__[(condition) ? 1 : -1])
 Issue a compilation error if the condition is false.
#define STATIC_ASSERT_EXPR(__cond)   (sizeof(struct { int STATIC_ASSERTION_FAILED__:!!(__cond); }) * 0)
 Issue a compilation error if __cond is false (this can be used inside an expression).
#define ACCESS_SAFE(x)   (*(volatile typeof(x) *)&(x))
 Prevent the compiler from optimizing access to the variable x, enforcing a refetch from memory.

Typedefs

typedef int32_t ticks_t
 Type for time expressed in ticks.
typedef int32_t utime_t
 Type for time expressed in microseconds.
typedef int32_t mtime_t
 Type for time expressed in milliseconds.
typedef void(* Hook )(void *)
 User defined callback type.
typedef void * iptr_t
 Bulk storage large enough for both pointers or integers.
typedef const void * const_iptr_t
 Bulk storage large enough for both pointers to constants or integers.
typedef unsigned char sigbit_t
 Type for signal bits.
typedef unsigned char sigmask_t
 Type for signal masks.
Types for hardware registers.

Only use these types for registers whose contents can be changed asynchronously by external hardware.

typedef volatile uint8_t reg8_t
typedef volatile uint16_t reg16_t
typedef volatile uint32_t reg32_t

Detailed Description

Additional support macros for compiler independance.

Author:
Bernie Innocenti <bernie@codewiz.org>

Definition in file compiler.h.


Define Documentation

#define ACCESS_SAFE (   x)    (*(volatile typeof(x) *)&(x))

Prevent the compiler from optimizing access to the variable x, enforcing a refetch from memory.

This also forbid from reordering successing instances of ACCESS_SAFE().

Definition at line 637 of file compiler.h.

#define alignof (   type)    offsetof(struct { char c; type member; }, member)

Return the alignment in memory of a generic data type.

Note:
We need to worry about alignment when allocating memory that will be used later by unknown objects (e.g., malloc()) or, more generally, whenever creating generic container types.

Definition at line 586 of file compiler.h.

#define COMPILER_VARIADIC_MACROS   1

usage:

Support for macros with variable arguments.

 #define foo_init(args...) PP_CAT(foo_init_, COUNT_PARMS(args)) (args)
#define containerof (   ptr,
  type,
  member 
)
Value:
({ \
        typeof( ((type *)0)->member ) *_mptr = (ptr); /* type check */ \
        (type *)(void *)((char *)_mptr - offsetof(type, member)); \
    })

Cast a member of a structure out to the containing structure.

Parameters:
ptrthe pointer to the member.
typethe type of the container struct this is embedded in.
memberthe name of the member within the struct.

Definition at line 597 of file compiler.h.

#define countof (   a)
Value:
(sizeof(a) / sizeof(*(a)) +     \
                STATIC_ASSERT_EXPR(         \
                    !__builtin_types_compatible_p(  \
                        typeof(a), typeof(&a[0]))))

Count the number of elements in the static array a.

Note:
This macro is non-standard, but implements a very common idiom

Definition at line 570 of file compiler.h.

#define offsetof (   s,
 
)    (size_t)&(((s *)0)->m)

Return the byte offset of the member m in struct s.

Note:
This macro should be defined in "stddef.h" and is sometimes compiler-specific (g++ has a builtin for it).

Definition at line 553 of file compiler.h.


Typedef Documentation

typedef const void* const_iptr_t

Bulk storage large enough for both pointers to constants or integers.

Definition at line 472 of file compiler.h.

typedef void* iptr_t

Bulk storage large enough for both pointers or integers.

Definition at line 469 of file compiler.h.

typedef int32_t mtime_t

Type for time expressed in milliseconds.

Definition at line 459 of file compiler.h.

typedef unsigned char sigbit_t

Type for signal bits.

Definition at line 474 of file compiler.h.

typedef unsigned char sigmask_t

Type for signal masks.

Definition at line 475 of file compiler.h.

typedef int32_t ticks_t

Type for time expressed in ticks.

Definition at line 452 of file compiler.h.

typedef int32_t utime_t

Type for time expressed in microseconds.

Definition at line 454 of file compiler.h.