Studio:Scl struct sized: Difference between revisions

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== Examples ==
== Examples ==


=== Example 1 ===
=== Example 1 ===
This example shows the declaration for a simple sized struct.
This example shows the declaration for a simple sized struct.
<source lang=c>
typedef struct {
    int nSize;
    int nSomeJunk;
    int nMoreJunk;
} SimpleSizedStruct;
extern void f(SimpleSizedStruct s);
#pragma scl_struct_sized(SimpleSizedStruct, nSize);
</source>
=== Example 2 ===
This example shows the declaration for a simple sized struct using a pointer.
<source lang=c>
<source lang=c>
typedef struct {
typedef struct {
Line 61: Line 46:


=== Example 2 ===
=== Example 2 ===
This example shows the declaration of a sized struct containing a conformant array.
This example shows the declaration of a sized struct with a conformant array.
<source lang=c>
<source lang=c>
#define SOME_BOUND 0
#define SOME_BOUND 0

Revision as of 00:55, 31 October 2008

The scl_struct_sized pragma

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 or Struct* Specifies a structure type that is to be sized (allocated bytes beyond its type definition).
  • 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).
max-size Integer Specifies the number of bytes for the sized struct.
  • The value contained by max_size may not be less than the structure's type size.
  • The max-size value must be an integral type (int, short, char).
  • The max-size may not exceed the maximum payload size.
  • The max_size must reside in the same payload block as the sized struct (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_struct_sized(f.s, nSize);

Example 2

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

#define SOME_BOUND 0
typedef struct {
    int nSize;
    int nSomeJunk;
    int ary[SOME_BOUND];
} ConformantArraySizedStruct;

extern void f(SimpleSizedStruct* s);
#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.