Studio:Scl struct sized

The scl_struct_sized pragma

The scl_struct_sized pragma is one of the Qualification pragmas. The scl_struct_sized pragma identifies a particular struct or pointer-to-struct as a sized structure. A sized structure typically has bytes allocated past its type definition.

Syntax

#pragma scl_struct_sized(type-name, max-size)

Parameters	Type	Description
type-name	Struct, Pointer	Specifies a structure type (or a pointer to such type) that is to be sized (allocated bytes beyond its type definition). The following restrictions apply: The structure type may not be pointed to by a sized pointer. The structure type may not be a member of any other structure or union. The structure type may not be passed as a function parameter. The structure type may only reside in IN/INOUT memory blocks. If the last member of the structure is an array, the array's size is calculated based upon max-size - (size of struct's other members). If the last member of the structure is an array, the array's element type may not contain a sized structure (scl_struct_sized) or a conformant array (scl_conform).
max-size	Integer	Specifies the number of bytes to be allocated for the sized struct. The following restrictions apply: The max-size type must be an integral type (int, short, char). The max-size value (at runtime) may not be less than the structure's type size. The max-size value (at runtime) may not exceed the maximum payload size. The max_size field must be in the same payload block as the type-name sized struct (i.e. no indirection '*' or '->').

Examples

Example 1

This example shows the declaration for a simple sized struct.

typedef struct {
    int nSize;
    int nSomeJunk;
    int nMoreJunk;
} SimpleSizedStruct;

extern void f(SimpleSizedStruct* s);
#pragma scl_function(f)
#pragma scl_struct_sized(f.s, nSize);

Example 2

This example shows the declaration of a sized struct with a conformant array.

#define SOME_BOUND 1
typedef struct {
    int nSize;
    int nSomeJunk;
    int ary[SOME_BOUND];
} ConformantArraySizedStruct;

extern void f(SimpleSizedStruct* s);
#pragma scl_function(f)
#pragma scl_struct_sized(f.s, nSize);

See Also

• For additional information on scl_string, including constraints, refer to the section on scl_struct_sized in the SCL Reference Guide.