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| author | Sergey Bugaev <bugaevc@gmail.com> | 2023-02-12 14:10:34 +0300 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2023-02-12 15:55:04 +0100 |
| commit | 62d6c3303089d9c708527ab7bf98348a6429e8c3 (patch) | |
| tree | 73a5a9637c522d97df9281137cb26c44809e9167 /hurd/fopenport.c | |
| parent | f4315054b46d5e58b44a709a51943fb73f846afb (diff) | |
| download | glibc-62d6c3303089d9c708527ab7bf98348a6429e8c3.tar.gz | |
mach, hurd: Cast through uintptr_t
When casting between a pointer and an integer of a different size, GCC
emits a warning (which is escalated to a build failure by -Werror).
Indeed, if what you start with is a pointer, which you then cast to a
shorter integer and then back again, you're going to cut off some bits
of the pointer.
But if you start with an integer (such as mach_port_t), then cast it to
a longer pointer (void *), and then back to a shorter integer, you are
fine. To keep GCC happy, cast through an intermediary uintptr_t, which
is always the same size as a pointer.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230212111044.610942-4-bugaevc@gmail.com>
Diffstat (limited to 'hurd/fopenport.c')
| -rw-r--r-- | hurd/fopenport.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/hurd/fopenport.c b/hurd/fopenport.c index 60afb44552..be6aa30c7e 100644 --- a/hurd/fopenport.c +++ b/hurd/fopenport.c @@ -28,9 +28,10 @@ readio (void *cookie, char *buf, size_t n) mach_msg_type_number_t nread; error_t err; char *bufp = buf; + io_t io = (io_t) (uintptr_t) cookie; nread = n; - if (err = __io_read ((io_t) cookie, &bufp, &nread, -1, n)) + if (err = __io_read (io, &bufp, &nread, -1, n)) return __hurd_fail (err); if (bufp != buf) @@ -50,8 +51,9 @@ writeio (void *cookie, const char *buf, size_t n) { vm_size_t wrote; error_t err; + io_t io = (io_t) (uintptr_t) cookie; - if (err = __io_write ((io_t) cookie, buf, n, -1, &wrote)) + if (err = __io_write (io, buf, n, -1, &wrote)) return __hurd_fail (err); return wrote; @@ -65,7 +67,8 @@ seekio (void *cookie, off64_t *pos, int whence) { - error_t err = __io_seek ((file_t) cookie, *pos, whence, pos); + io_t io = (io_t) (uintptr_t) cookie; + error_t err = __io_seek (io, *pos, whence, pos); return err ? __hurd_fail (err) : 0; } @@ -74,8 +77,9 @@ seekio (void *cookie, static int closeio (void *cookie) { + io_t io = (io_t) (uintptr_t) cookie; error_t error = __mach_port_deallocate (__mach_task_self (), - (mach_port_t) cookie); + io); if (error) return __hurd_fail (error); return 0; @@ -127,6 +131,7 @@ __fopenport (mach_port_t port, const char *mode) return NULL; } - return fopencookie ((void *) port, mode, funcsio); + return fopencookie ((void *) (uintptr_t) port, + mode, funcsio); } weak_alias (__fopenport, fopenport) |