Re: [PATCH] device_tree: Fix compiler error

[Laurent Vivier]

Le 08/11/2021 à 21:07, Stefan Weil a écrit :
> A build with gcc (Debian 10.2.1-6) 10.2.1 20210110 fails:
>
> ../../../softmmu/device_tree.c: In function ‘qemu_fdt_add_path’:
> ../../../softmmu/device_tree.c:560:18: error: ‘retval’ may be used 
> uninitialized in this function [-Werror=maybe-uninitialized]
>    560 |     int namelen, retval;
>        |                  ^~~~~~
>
> This is not a real error, but the compiler can be satisfied with a small change.
>
> Fixes: b863f0b75852 ("device_tree: Add qemu_fdt_add_path")
> Signed-off-by: Stefan Weil <sw@weilnetz.de>
> ---
>   softmmu/device_tree.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/softmmu/device_tree.c b/softmmu/device_tree.c
> index 3965c834ca..9e96f5ecd5 100644
> --- a/softmmu/device_tree.c
> +++ b/softmmu/device_tree.c
> @@ -564,7 +564,7 @@ int qemu_fdt_add_path(void *fdt, const char *path)
>           return -1;
>       }
>   
> -    while (p) {
> +    do {
>           name = p + 1;
>           p = strchr(name, '/');
>           namelen = p != NULL ? p - name : strlen(name);
> @@ -584,7 +584,7 @@ int qemu_fdt_add_path(void *fdt, const char *path)
>           }
>   
>           parent = retval;
> -    }
> +    } while (p);
>   
>       return retval;
>   }

I think to add a "g_assert_nonull(p);" before the loop would inform the compiler that we always go 
in the loop and remove the compiler error.

Thanks,
Laurent