Re: [PATCH 4/4] virtiofsd: avoid false positive compiler warning

[Dr. David Alan Gilbert]

* Christian Borntraeger (borntraeger@de.ibm.com) wrote:
> make: *** [Makefile:121: config-host.mak] Error 1
> [cborntra@m83lp52 qemu]$ make -C build/
> make: Entering directory '/home/cborntra/REPOS/qemu/build'
> Generating qemu-version.h with a meson_exe.py custom command
> Compiling C object tools/virtiofsd/virtiofsd.p/passthrough_ll.c.o
> ../tools/virtiofsd/passthrough_ll.c: In function ‘lo_setattr’:
> ../tools/virtiofsd/passthrough_ll.c:702:19: error: ‘fd’ may be used 
> uninitialized in this function [-Werror=maybe-uninitialized]
>   702 |             res = futimens(fd, tv);
>       |                   ^~~~~~~~~~~~~~~~
> cc1: all warnings being treated as errors
> make: *** [Makefile.ninja:1438: 
> tools/virtiofsd/virtiofsd.p/passthrough_ll.c.o] Error 1
> make: Leaving directory '/home/cborntra/REPOS/
> 
> as far as I can see this can not happen. Let us silence the warning by
> giving fd a default value.
> 
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Yeh, I'd posted 
https://www.mail-archive.com/qemu-devel@nongnu.org/msg738783.html
but not yet merged it; only difference is I'd used -1 since it seemd
safer to use -1 even if it couldn't happen :-)

Dave

> ---
>  tools/virtiofsd/passthrough_ll.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/virtiofsd/passthrough_ll.c 
> b/tools/virtiofsd/passthrough_ll.c
> index 0b229ebd5786..da06aa6e9264 100644
> --- a/tools/virtiofsd/passthrough_ll.c
> +++ b/tools/virtiofsd/passthrough_ll.c
> @@ -620,7 +620,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, 
> struct stat *attr,
>      struct lo_inode *inode;
>      int ifd;
>      int res;
> -    int fd;
> +    int fd = 0;
>  
>      inode = lo_inode(req, ino);
>      if (!inode) {
> -- 
> 2.26.2
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK