Declaring and Initializing Structure Handles

STRUCT_DECL(9F) and STRUCT_INIT(9F) can be used to declare and initialize a handle and space for decoding an ioctl on the stack. STRUCT_HANDLE(9F) and STRUCT_SET_HANDLE(9F) declare and initialize a handle without allocating space on the stack. The latter macros can be useful if the structure is very large, or is contained in some other data structure.

Because the STRUCT_DECL() and STRUCT_HANDLE() macros expand to data structure declarations, they should be grouped with such declarations in C code.

STRUCT_DECL(structname, handle)

Declares a structure handle called handle for a struct structname data structure, and allocates space for its native form on the stack. The native form is assumed to be larger than or equal to the ILP32 form of the structure.

STRUCT_INIT(handle, umodel)

Initializes the data model for handle to umodel. This macro must be invoked before any access is made to a structure handle declared with STRUCT_DECL().

STRUCT_HANDLE(structname, handle)

Declares a structure handle called handle. Contrast with STRUCT_DECL().

STRUCT_SET_HANDLE(handle, umodel, addr)

Initializes the data model for handle to umodel, and sets addr as the buffer used for subsequent manipulation. Invoke this macro before accessing a structure handle declared with STRUCT_HANDLE().