| Message ID | 20230621213444.2017-2-cristian@rodriguez.im |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
This patch only syncs with the current kernel headers. On Wed, Jun 21, 2023 at 5:35 PM Cristian Rodríguez <cristian@rodriguez.im> wrote: > Current kernel versions require a compiler supporting -std=gnu11 > and therefore supporting C99 flexible arrays. old versions require > a c89 compiler supporting this feature as an extension. > > Signed-off-by: Cristian Rodríguez <cristian@rodriguez.im> > --- > sysdeps/unix/sysv/linux/sys/inotify.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/sysdeps/unix/sysv/linux/sys/inotify.h > b/sysdeps/unix/sysv/linux/sys/inotify.h > index 1e8e68cd97..535f57e27b 100644 > --- a/sysdeps/unix/sysv/linux/sys/inotify.h > +++ b/sysdeps/unix/sysv/linux/sys/inotify.h > @@ -31,7 +31,7 @@ struct inotify_event > uint32_t mask; /* Watch mask. */ > uint32_t cookie; /* Cookie to synchronize two events. */ > uint32_t len; /* Length (including NULs) of name. */ > - char name __flexarr; /* Name. */ > + char name[]; /* Name. */ > }; > > > -- > 2.41.0 > >
* Cristian Rodríguez via Libc-alpha: > Current kernel versions require a compiler supporting -std=gnu11 > and therefore supporting C99 flexible arrays. old versions require > a c89 compiler supporting this feature as an extension. Ugh, you are right: commit 94dfc73e7cf4a31da66b8843f0b9283ddd6b8381 Author: Gustavo A. R. Silva <gustavoars@kernel.org> Date: Wed Apr 6 19:36:51 2022 -0500 treewide: uapi: Replace zero-length arrays with flexible-array members It's specifically targeting UAPI headers, so it's not a (harmless) kernel-internal change. Do you know if anyone has looked at the compatibility impact of this change on C parsers? I'm not sure if we can do the same thing. In particular, if kernel headers are not C89-compatible, we may have to add kludges to our own headers that avoid including them in C89 mode. Thanks, Florian
On Thu, Jun 22, 2023 at 1:23 AM Florian Weimer <fweimer@redhat.com> wrote: > > Do you know if anyone has looked at the compatibility impact of this > change on C parsers? I'm not sure if we can do the same thing. In > particular, if kernel headers are not C89-compatible, we may have to add > kludges to our own headers that avoid including them in C89 mode. > > > On this case it is a linux feature, which has required this as an extension, probably since forever. I have only checked kernel 3.2 as the minimum and that version indeed uses c99 flex arrays at least *internally* (I have not checked all headers though)
diff --git a/sysdeps/unix/sysv/linux/sys/inotify.h b/sysdeps/unix/sysv/linux/sys/inotify.h index 1e8e68cd97..535f57e27b 100644 --- a/sysdeps/unix/sysv/linux/sys/inotify.h +++ b/sysdeps/unix/sysv/linux/sys/inotify.h @@ -31,7 +31,7 @@ struct inotify_event uint32_t mask; /* Watch mask. */ uint32_t cookie; /* Cookie to synchronize two events. */ uint32_t len; /* Length (including NULs) of name. */ - char name __flexarr; /* Name. */ + char name[]; /* Name. */ };
Current kernel versions require a compiler supporting -std=gnu11 and therefore supporting C99 flexible arrays. old versions require a c89 compiler supporting this feature as an extension. Signed-off-by: Cristian Rodríguez <cristian@rodriguez.im> --- sysdeps/unix/sysv/linux/sys/inotify.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)