CrossWorks for ARM User Guide

char ch = (char)va_arg(ap, int);Portabilityva_arg conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).See also va_copy (page 279), va_end (page 279), va_end (page 279)va_copySynopsisDescriptionPortability#include void va_copy(va_list dest, va_list src);va_copy initializes dest as a copy of src, as if the va_start macro had been applied todest followed by the same sequence of uses of the va_arg macro as had previously beenused to reach the present state of src. Neither the va_copy nor va_start macro shall beinvoked to reinitialize dest without an intervening invocation of the va_end macro forthe same dest.va_copy conforms to ISO/IEC 9899:1999 (C99).See also va_arg (page 278), va_end (page 279), va_end (page 279)va_endSynopsisDescriptionPortability#include void va_end(va_list ap);va_end indicates a normal return from the function whose variable argument list apwas initialised by va_start or va_copy. The va_end macro may modify ap so that it isno longer usable without being reinitialized by va_start or va_copy. If there is nocorresponding invocation of va_start or va_copy, or if va_end is not invoked before thereturn, the behavior is undefined.va_end conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).See also va_arg (page 278), va_copy (page 279), va_end (page 279)va_endSynopsisDescription#include void va_start(va_list ap, parmN);va_start initializes ap for subsequent use by the va_arg and va_end macros.The parameter parmN is the identifier of the last fixed parameter in the variableparameter list in the function definition (the one just before the ', ...').Chapter 28 - Variable arguments279