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#ifdef __wasilibc_unmodified_upstream // WASI has no syscall, dup
#include "stdio_impl.h"
#else
#include <wasi/libc.h>
#endif
#include <fcntl.h>
#include <unistd.h>
#ifdef __wasilibc_unmodified_upstream // WASI has no syscall, dup
#else
// Move this below fcntl.h and unistd.h so that the __syscall macro doesn't
// cause trouble.
#include "stdio_impl.h"
#endif
/* The basic idea of this implementation is to open a new FILE,
* hack the necessary parts of the new FILE into the old one, then
* close the new FILE. */
/* Locking IS necessary because another thread may provably hold the
* lock, via flockfile or otherwise, when freopen is called, and in that
* case, freopen cannot act until the lock is released. */
FILE *freopen(const char *restrict filename, const char *restrict mode, FILE *restrict f)
{
int fl = __fmodeflags(mode);
FILE *f2;
FLOCK(f);
fflush(f);
if (!filename) {
if (fl&O_CLOEXEC)
#ifdef __wasilibc_unmodified_upstream // WASI has no syscall
__syscall(SYS_fcntl, f->fd, F_SETFD, FD_CLOEXEC);
#else
fcntl(f->fd, F_SETFD, FD_CLOEXEC);
#endif
fl &= ~(O_CREAT|O_EXCL|O_CLOEXEC);
#ifdef __wasilibc_unmodified_upstream // WASI has no syscall
if (syscall(SYS_fcntl, f->fd, F_SETFL, fl) < 0)
#else
if (fcntl(f->fd, F_SETFL, fl) < 0)
#endif
goto fail;
} else {
f2 = fopen(filename, mode);
if (!f2) goto fail;
if (f2->fd == f->fd) f2->fd = -1; /* avoid closing in fclose */
#ifdef __wasilibc_unmodified_upstream // WASI has no dup
else if (__dup3(f2->fd, f->fd, fl&O_CLOEXEC)<0) goto fail2;
#else
// WASI doesn't have dup3, but does have a way to renumber
// an existing file descriptor.
else {
if (__wasilibc_fd_renumber(f2->fd, f->fd)<0) goto fail2;
f2->fd = -1; /* avoid closing in fclose */
}
#endif
f->flags = (f->flags & F_PERM) | f2->flags;
f->read = f2->read;
f->write = f2->write;
f->seek = f2->seek;
f->close = f2->close;
fclose(f2);
}
FUNLOCK(f);
return f;
fail2:
fclose(f2);
fail:
fclose(f);
return NULL;
}
weak_alias(freopen, freopen64);
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