mirror of
https://github.com/fluencelabs/musl
synced 2025-06-03 10:01:38 +00:00
400c5e5c83
to deal with the fact that the public headers may be used with pre-c99 compilers, __restrict is used in place of restrict, and defined appropriately for any supported compiler. we also avoid the form [restrict] since older versions of gcc rejected it due to a bug in the original c99 standard, and instead use the form *restrict.
39 lines
857 B
C
39 lines
857 B
C
#include "stdio_impl.h"
|
|
|
|
static size_t sn_write(FILE *f, const unsigned char *s, size_t l)
|
|
{
|
|
size_t k = f->wend - f->wpos;
|
|
if (k > l) k = l;
|
|
memcpy(f->wpos, s, k);
|
|
f->wpos += k;
|
|
/* pretend to succeed, but discard extra data */
|
|
return l;
|
|
}
|
|
|
|
int vsnprintf(char *restrict s, size_t n, const char *restrict fmt, va_list ap)
|
|
{
|
|
int r;
|
|
char b;
|
|
FILE f = { .lbf = EOF, .write = sn_write, .lock = -1 };
|
|
|
|
if (n-1 > INT_MAX-1) {
|
|
if (n) {
|
|
errno = EOVERFLOW;
|
|
return -1;
|
|
}
|
|
s = &b;
|
|
n = 1;
|
|
}
|
|
|
|
/* Ensure pointers don't wrap if "infinite" n is passed in */
|
|
if (n > (char *)0+SIZE_MAX-s-1) n = (char *)0+SIZE_MAX-s-1;
|
|
f.buf_size = n;
|
|
f.buf = f.wpos = (void *)s;
|
|
f.wbase = f.wend = (void *)(s+n);
|
|
r = vfprintf(&f, fmt, ap);
|
|
|
|
/* Null-terminate, overwriting last char if dest buffer is full */
|
|
if (n) f.wpos[-(f.wpos == f.wend)] = 0;
|
|
return r;
|
|
}
|