Re: [PATCH v2] perf riscv: Fix discarded const qualifier in _get_field()

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Sun, May 24, 2026 at 02:41:26AM +0800, Li Guan wrote:
> Hi Arnaldo, Namhyung,
> 
> Just a gentle ping on this patch. It has received a Reviewed-by from Ian.
> Could you please consider picking it up for perf-tools-next?

Thanks, applying.

- Arnaldo

> Thanks,
> Li Guan
> 
> On 5/14/2026 2:07 AM, Li Guan wrote:
> > The assignment of strrchr() return values to non-const char * variables
> > triggers a -Werror=discarded-qualifiers warning when building with GCC 14.
> > This happens because in newer glibc versions, strrchr() returns a
> > const char * if the input string is const.
> > 
> > Properly declare 'line2' and 'nl' as const char * to match the glibc
> > function signature and ensure type safety. This avoids the need for
> > explicit type casting and aligns with the design pattern of not
> > modifying read-only memory in the perf tool.
> > 
> > Signed-off-by: Li Guan <guanli.oerv@isrc.iscas.ac.cn>
> > ---
> > v2:
> >   - Drop the auxtrace decoupling and weak stub approach as they interfered
> >     with the cross-platform analysis intent, per Ian's feedback.
> >   - Focus on a clean fix for the const qualifier issue in RISC-V header.c
> >     by properly declaring local variables as const.
> >   - Use Li Guan as the preferred name format for consistency.
> >   - Verified that this fix is not yet present in acme/perf-tools-next.
> > 
> >   tools/perf/arch/riscv/util/header.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/tools/perf/arch/riscv/util/header.c b/tools/perf/arch/riscv/util/header.c
> > index 4b839203d4..891984e909 100644
> > --- a/tools/perf/arch/riscv/util/header.c
> > +++ b/tools/perf/arch/riscv/util/header.c
> > @@ -19,7 +19,7 @@
> >   static char *_get_field(const char *line)
> >   {
> > -	char *line2, *nl;
> > +	const char *line2, *nl;
> >   	line2 = strrchr(line, ' ');
> >   	if (!line2)