Files
semi-libc/src/stdio/open_wmemstream.c
T
Rich Felker 5ce3737931 reduce spurious inclusion of libc.h
libc.h was intended to be a header for access to global libc state and
related interfaces, but ended up included all over the place because
it was the way to get the weak_alias macro. most of the inclusions
removed here are places where weak_alias was needed. a few were
recently introduced for hidden. some go all the way back to when
libc.h defined CANCELPT_BEGIN and _END, and all (wrongly implemented)
cancellation points had to include it.

remaining spurious users are mostly callers of the LOCK/UNLOCK macros
and files that use the LFS64 macro to define the awful *64 aliases.

in a few places, new inclusion of libc.h is added because several
internal headers no longer implicitly include libc.h.

declarations for __lockfile and __unlockfile are moved from libc.h to
stdio_impl.h so that the latter does not need libc.h. putting them in
libc.h made no sense at all, since the macros in stdio_impl.h are
needed to use them correctly anyway.
2018-09-12 14:34:37 -04:00

103 lines
1.9 KiB
C

#include "stdio_impl.h"
#include <wchar.h>
#include <errno.h>
#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include "libc.h"
struct cookie {
wchar_t **bufp;
size_t *sizep;
size_t pos;
wchar_t *buf;
size_t len;
size_t space;
mbstate_t mbs;
};
struct wms_FILE {
FILE f;
struct cookie c;
unsigned char buf[1];
};
static off_t wms_seek(FILE *f, off_t off, int whence)
{
ssize_t base;
struct cookie *c = f->cookie;
if (whence>2U) {
fail:
errno = EINVAL;
return -1;
}
base = (size_t [3]){0, c->pos, c->len}[whence];
if (off < -base || off > SSIZE_MAX/4-base) goto fail;
memset(&c->mbs, 0, sizeof c->mbs);
return c->pos = base+off;
}
static size_t wms_write(FILE *f, const unsigned char *buf, size_t len)
{
struct cookie *c = f->cookie;
size_t len2;
wchar_t *newbuf;
if (len + c->pos >= c->space) {
len2 = 2*c->space+1 | c->pos+len+1;
if (len2 > SSIZE_MAX/4) return 0;
newbuf = realloc(c->buf, len2*4);
if (!newbuf) return 0;
*c->bufp = c->buf = newbuf;
memset(c->buf + c->space, 0, 4*(len2 - c->space));
c->space = len2;
}
len2 = mbsnrtowcs(c->buf+c->pos, (void *)&buf, len, c->space-c->pos, &c->mbs);
if (len2 == -1) return 0;
c->pos += len2;
if (c->pos >= c->len) c->len = c->pos;
*c->sizep = c->pos;
return len;
}
static int wms_close(FILE *f)
{
return 0;
}
FILE *open_wmemstream(wchar_t **bufp, size_t *sizep)
{
struct wms_FILE *f;
wchar_t *buf;
if (!(f=malloc(sizeof *f))) return 0;
if (!(buf=malloc(sizeof *buf))) {
free(f);
return 0;
}
memset(&f->f, 0, sizeof f->f);
memset(&f->c, 0, sizeof f->c);
f->f.cookie = &f->c;
f->c.bufp = bufp;
f->c.sizep = sizep;
f->c.pos = f->c.len = f->c.space = *sizep = 0;
f->c.buf = *bufp = buf;
*buf = 0;
f->f.flags = F_NORD;
f->f.fd = -1;
f->f.buf = f->buf;
f->f.buf_size = 0;
f->f.lbf = EOF;
f->f.write = wms_write;
f->f.seek = wms_seek;
f->f.close = wms_close;
if (!libc.threaded) f->f.lock = -1;
fwide(&f->f, 1);
return __ofl_add(&f->f);
}