On 28/10/2024 11:48 am, Roger Pau Monne wrote:
> Clang 19 complains with the following error when building libxl:
>
> libxl_utils.c:48:15: error: variable length array folded to constant array as
> an extension [-Werror,-Wgnu-folding-constant]
> 48 | char path[strlen("/local/domain") + 12];
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Replace the usage of strlen() with ARRAY_SIZE(), which allows the literal
> string length to be known at build time. Note ARRAY_SIZE() accounts for the
> NUL terminator while strlen() didn't, hence subtract 1 from the total size
> calculation.
>
> Signed-off-by: Roger Pau Monné <roger....@citrix.com>
> ---
> tools/libs/light/libxl_utils.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/libs/light/libxl_utils.c b/tools/libs/light/libxl_utils.c
> index 10398a6c8611..b3f5e751cc3f 100644
> --- a/tools/libs/light/libxl_utils.c
> +++ b/tools/libs/light/libxl_utils.c
> @@ -45,7 +45,7 @@ unsigned long libxl_get_required_shadow_memory(unsigned
> long maxmem_kb, unsigned
> char *libxl_domid_to_name(libxl_ctx *ctx, uint32_t domid)
> {
> unsigned int len;
> - char path[strlen("/local/domain") + 12];
> + char path[ARRAY_SIZE("/local/domain") + 11];
> char *s;
>
> snprintf(path, sizeof(path), "/local/domain/%d/name", domid);
> @@ -141,7 +141,7 @@ int libxl_cpupool_qualifier_to_cpupoolid(libxl_ctx *ctx,
> const char *p,
> char *libxl_cpupoolid_to_name(libxl_ctx *ctx, uint32_t poolid)
> {
> unsigned int len;
> - char path[strlen("/local/pool") + 12];
> + char path[ARRAY_SIZE("/local/pool") + 11];
> char *s;
>
> snprintf(path, sizeof(path), "/local/pool/%d/name", poolid);
Acked-by: Andrew Cooper <andrew.coop...@citrix.com>
Although I have a minor preference for sizeof() as suggested by Frediano.
Can fix on commit, if you're happy?
~Andrew
