Altera Nios II C2H Compiler - Manual (Page 69)

Altera Corporation 9.1 3–29
November 2009 Nios II C2H Compiler User Guide
C-to-Hardware Mapping Reference
Consider the simple struct declaration shown in Example 3–22 .
Example 3–22. Structure Declaration
struct s
{
int element_a;
int element_b;
int element_c;
} my_struct;
In this example, the expression (my_struct.c) translates to the
following:
*((int *)((void *)&my_struct + 2*sizeof(int)))
Structure Pointer Operator ->
The structure pointer operator is used to access a single member of a
structure or union via a pointer to the structure or union. The structure
pointer operator behaves similarly to the member operator, except that
the left-hand side of the operator must be a pointer.
The structure pointer operation on a struct( e.g. mystruct->a) is
equivalent to Example 3–23 .
Example 3–23. Converted struct Pointer Operation
*((pointer_to_type_of_a) ((void *)mystruct + offset_of_a))
The structure pointer operation on a union (e.g. myunion->a) is
equivalent to Example 3–24 .
Example 3–24. Converted union Pointer Operation
*((pointer_to_type_of_a)myunion)