Executes initialization processing for referencing variable arguments.

[Format]

#include <stdarg.h>

void va_start (va_list ap, parmN);

[Parameters]

ap Variable for accessing variable arguments

parmN Identifier of rightmost argument

[Remarks]

The va_start macro initializes ap for subsequent use by the va_arg and va_end macros.

The argument parmN is the identifier of the rightmost argument in the argument list in the external function definition (the one just before the , ...).

To reference variable unnamed arguments, the va_start macro call must be executed first of all.