From 8c1ab65c0f548d20b7f177bdb736daaf603340e1 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 15:54:38 +0200 Subject: Adding upstream version 0.0~git20221206.8b7148f. Signed-off-by: Daniel Baumann --- libc-top-half/musl/src/stdio/freopen.c | 80 ++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 libc-top-half/musl/src/stdio/freopen.c (limited to 'libc-top-half/musl/src/stdio/freopen.c') diff --git a/libc-top-half/musl/src/stdio/freopen.c b/libc-top-half/musl/src/stdio/freopen.c new file mode 100644 index 0000000..5331db0 --- /dev/null +++ b/libc-top-half/musl/src/stdio/freopen.c @@ -0,0 +1,80 @@ +#ifdef __wasilibc_unmodified_upstream // WASI has no syscall, dup +#include "stdio_impl.h" +#else +#include +#endif +#include +#include +#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); -- cgit v1.2.3