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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 /mach | |
| parent | f4315054b46d5e58b44a709a51943fb73f846afb (diff) | |
| download | glibc-62d6c3303089d9c708527ab7bf98348a6429e8c3.zip glibc-62d6c3303089d9c708527ab7bf98348a6429e8c3.tar.gz glibc-62d6c3303089d9c708527ab7bf98348a6429e8c3.tar.bz2 | |
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 'mach')
| -rw-r--r-- | mach/devstream.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/mach/devstream.c b/mach/devstream.c index 09272d1..cfa9a4f 100644 --- a/mach/devstream.c +++ b/mach/devstream.c @@ -28,7 +28,7 @@ static ssize_t devstream_write (void *cookie, const char *buffer, size_t n) { - const device_t dev = (device_t) cookie; + const device_t dev = (device_t) (uintptr_t) cookie; int write_some (const char *p, size_t to_write) { @@ -83,7 +83,7 @@ devstream_write (void *cookie, const char *buffer, size_t n) static ssize_t devstream_read (void *cookie, char *buffer, size_t to_read) { - const device_t dev = (device_t) cookie; + const device_t dev = (device_t) (uintptr_t) cookie; kern_return_t err; mach_msg_type_number_t nread = to_read; @@ -112,7 +112,8 @@ devstream_read (void *cookie, char *buffer, size_t to_read) static int dealloc_ref (void *cookie) { - if (__mach_port_deallocate (mach_task_self (), (mach_port_t) cookie)) + const device_t dev = (device_t) (uintptr_t) cookie; + if (__mach_port_deallocate (mach_task_self (), dev)) { errno = EINVAL; return -1; @@ -131,7 +132,7 @@ mach_open_devstream (mach_port_t dev, const char *mode) return NULL; } - stream = _IO_fopencookie ((void *) dev, mode, + stream = _IO_fopencookie ((void *) (uintptr_t) dev, mode, (cookie_io_functions_t) { write: devstream_write, read: devstream_read, close: dealloc_ref }); |