perf: Fix libjvmti.c sign compare error

[PATCH v1] perf: Fix libjvmti.c sign compare error

Posted by Yuzhuo Jing 6 months, 2 weeks ago

Fix the compile errors when compiling with -Werror=sign-compare.

This is a follow-up patch to a previous patch series for a separate
issue.  Link: https://lore.kernel.org/lkml/aC9lXhPFcs5fkHWH@x1/

Signed-off-by: Yuzhuo Jing <yuzhuo@google.com>
---
 tools/perf/jvmti/libjvmti.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/jvmti/libjvmti.c b/tools/perf/jvmti/libjvmti.c
index fcca275e5bf9..82514e6532b8 100644
--- a/tools/perf/jvmti/libjvmti.c
+++ b/tools/perf/jvmti/libjvmti.c
@@ -141,11 +141,11 @@ copy_class_filename(const char * class_sign, const char * file_name, char * resu
 	* Assume path name is class hierarchy, this is a common practice with Java programs
 	*/
 	if (*class_sign == 'L') {
-		int j, i = 0;
+		size_t j, i = 0;
 		char *p = strrchr(class_sign, '/');
 		if (p) {
 			/* drop the 'L' prefix and copy up to the final '/' */
-			for (i = 0; i < (p - class_sign); i++)
+			for (i = 0; i < (size_t)(p - class_sign); i++)
 				result[i] = class_sign[i+1];
 		}
 		/*
-- 
2.50.0.rc1.591.g9c95f17f64-goog

Re: [PATCH v1] perf: Fix libjvmti.c sign compare error

Posted by Namhyung Kim 6 months, 1 week ago

On Wed, 04 Jun 2025 10:36:32 -0700, Yuzhuo Jing wrote:
> Fix the compile errors when compiling with -Werror=sign-compare.
> 
> This is a follow-up patch to a previous patch series for a separate
> issue.  Link: https://lore.kernel.org/lkml/aC9lXhPFcs5fkHWH@x1/
> 
> 
Applied to perf-tools-next, thanks!

Best regards,
Namhyung

Re: [PATCH v1] perf: Fix libjvmti.c sign compare error

Posted by Ian Rogers 6 months, 2 weeks ago

On Wed, Jun 4, 2025 at 10:36 AM Yuzhuo Jing <yuzhuo@google.com> wrote:
>
> Fix the compile errors when compiling with -Werror=sign-compare.
>
> This is a follow-up patch to a previous patch series for a separate
> issue.  Link: https://lore.kernel.org/lkml/aC9lXhPFcs5fkHWH@x1/
>
> Signed-off-by: Yuzhuo Jing <yuzhuo@google.com>

Reviewed-by: Ian Rogers <irogers@google.com>

Thanks,
Ian
> ---
>  tools/perf/jvmti/libjvmti.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/jvmti/libjvmti.c b/tools/perf/jvmti/libjvmti.c
> index fcca275e5bf9..82514e6532b8 100644
> --- a/tools/perf/jvmti/libjvmti.c
> +++ b/tools/perf/jvmti/libjvmti.c
> @@ -141,11 +141,11 @@ copy_class_filename(const char * class_sign, const char * file_name, char * resu
>         * Assume path name is class hierarchy, this is a common practice with Java programs
>         */
>         if (*class_sign == 'L') {
> -               int j, i = 0;
> +               size_t j, i = 0;
>                 char *p = strrchr(class_sign, '/');
>                 if (p) {
>                         /* drop the 'L' prefix and copy up to the final '/' */
> -                       for (i = 0; i < (p - class_sign); i++)
> +                       for (i = 0; i < (size_t)(p - class_sign); i++)
>                                 result[i] = class_sign[i+1];
>                 }
>                 /*
> --
> 2.50.0.rc1.591.g9c95f17f64-goog
>