selftests: cachestat: Fix warning on declaration under label

[PATCH v1] selftests: cachestat: Fix warning on declaration under label

Posted by Sidharth Seela 2 days, 9 hours ago

Fix warning caused from declaration under a case label. The proper way
is to declare variable at the beginning of the function. The warning
came from running clang using LLVM=1; and is as follows:
--
-test_cachestat.c:260:3: warning: label followed by a declaration is a C23 extension [-Wc23-extensions]
  260 |                 char *map = mmap(NULL, filesize, PROT_READ | PROT_WRITE,
      |

Signed-off-by: Sidharth Seela <sidharthseela@gmail.com>
---

diff --git a/tools/testing/selftests/cachestat/test_cachestat.c b/tools/testing/selftests/cachestat/test_cachestat.c
index c952640f163b..0305e736f2b8 100644
--- a/tools/testing/selftests/cachestat/test_cachestat.c
+++ b/tools/testing/selftests/cachestat/test_cachestat.c
@@ -226,7 +226,7 @@ bool run_cachestat_test(enum file_type type)
 	int syscall_ret;
 	size_t compute_len = PS * 512;
 	struct cachestat_range cs_range = { PS, compute_len };
-	char *filename = "tmpshmcstat";
+	char *filename = "tmpshmcstat", *map;
 	struct cachestat cs;
 	bool ret = true;
 	int fd;
@@ -257,7 +257,7 @@ bool run_cachestat_test(enum file_type type)
 		}
 		break;
 	case FILE_MMAP:
-		char *map = mmap(NULL, filesize, PROT_READ | PROT_WRITE,
+		map = mmap(NULL, filesize, PROT_READ | PROT_WRITE,
 				 MAP_SHARED, fd, 0);
 
 		if (map == MAP_FAILED) {
-- 
2.47.3

Re: [PATCH v1] selftests: cachestat: Fix warning on declaration under label

Posted by Dev Jain 1 day, 16 hours ago

On 29/09/25 5:24 pm, Sidharth Seela wrote:
> Fix warning caused from declaration under a case label. The proper way
> is to declare variable at the beginning of the function. The warning
> came from running clang using LLVM=1; and is as follows:
> --
> -test_cachestat.c:260:3: warning: label followed by a declaration is a C23 extension [-Wc23-extensions]
>    260 |                 char *map = mmap(NULL, filesize, PROT_READ | PROT_WRITE,
>        |
>
> Signed-off-by: Sidharth Seela <sidharthseela@gmail.com>
> ---
>

Reviewed-by: Dev Jain <dev.jain@arm.com>

Re: [PATCH v1] selftests: cachestat: Fix warning on declaration under label

Posted by SeongJae Park 2 days, 4 hours ago

On Mon, 29 Sep 2025 17:24:06 +0530 Sidharth Seela <sidharthseela@gmail.com> wrote:

> Fix warning caused from declaration under a case label. The proper way
> is to declare variable at the beginning of the function. The warning
> came from running clang using LLVM=1; and is as follows:
> --
> -test_cachestat.c:260:3: warning: label followed by a declaration is a C23 extension [-Wc23-extensions]
>   260 |                 char *map = mmap(NULL, filesize, PROT_READ | PROT_WRITE,
>       |
> 
> Signed-off-by: Sidharth Seela <sidharthseela@gmail.com>

Reviewed-by: SeongJae Park <sj@kernel.org>


Thanks,
SJ

[...]

Re: [PATCH v1] selftests: cachestat: Fix warning on declaration under label

Posted by lianux 1 day, 18 hours ago

From: wang lian <lianux.mm@gmail.com>

Reviewed-by: wang lian <lianux.mm@gmail.com>

> Fix warning caused from declaration under a case label. The proper way
> is to declare variable at the beginning of the function. The warning
> came from running clang using LLVM=1; and is as follows:
> --
> -test_cachestat.c:260:3: warning: label followed by a declaration is a C23 extension [-Wc23-extensions]
>   260 |                 char *map = mmap(NULL, filesize, PROT_READ | PROT_WRITE,
>       |
> 
> Signed-off-by: Sidharth Seela <sidharthseela@gmail.com>

Best regards,
wang lian