wmii/lib/libfmt/sprint.c

41 lines
1.3 KiB
C

/*
* The authors of this software are Rob Pike and Ken Thompson.
* Copyright (c) 2002 by Lucent Technologies.
* Permission to use, copy, modify, and distribute this software for any
* purpose without fee is hereby granted, provided that this entire notice
* is included in all copies of any software which is or includes a copy
* or modification of this software and in all copies of the supporting
* documentation for such software.
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE
* ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
*/
#include <stdarg.h>
#include "plan9.h"
#include "fmtdef.h"
int
sprint(char *buf, const char *fmt, ...)
{
int n;
uint len;
va_list args;
len = 1<<30; /* big number, but sprint is deprecated anyway */
/*
* on PowerPC, the stack is near the top of memory, so
* we must be sure not to overflow a 32-bit pointer.
*
* careful! gcc-4.2 assumes buf+len < buf can never be true and
* optimizes the test away. casting to uintptr works around this bug.
*/
if((uintptr_t)buf+len < (uintptr_t)buf)
len = -(uintptr_t)buf-1;
va_start(args, fmt);
n = vsnprint(buf, len, fmt, args);
va_end(args);
return n;
}