A recent strengthening of -Wunused-but-set-variable (enabled with -Wall)
in clang under a new subwarning, -Wunused-but-set-global, points out an
unused static global variable in dtc-lexer.lex.c (compiled from
dtc-lexer.l):

  scripts/dtc/dtc-lexer.lex.c:641:12: warning: variable 'dts_version' set but not used [-Wunused-but-set-global]
    641 | static int dts_version = 1;
        |            ^

This variable has been unused since commit 658f29a51e98 ("of/flattree:
Update dtc to current mainline."). Remove it to clear up the warning.

Cc: stable@vger.kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
This is commit 53373d1 ("dtc: Remove unused dts_version in dtc-lexer.l")
in upstream dtc. I sent it separately to make it easier to backport to
stable, along with updating the warning and hash to match the kernel's
version.
---
 scripts/dtc/dtc-lexer.l | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/scripts/dtc/dtc-lexer.l b/scripts/dtc/dtc-lexer.l
index 15d585c80798..1b129b118b0f 100644
--- a/scripts/dtc/dtc-lexer.l
+++ b/scripts/dtc/dtc-lexer.l
@@ -39,8 +39,6 @@ extern bool treesource_error;
 #define DPRINT(fmt, ...)	do { } while (0)
 #endif
 
-static int dts_version = 1;
-
 #define BEGIN_DEFAULT()		DPRINT("<V1>\n"); \
 				BEGIN(V1); \
 
@@ -101,7 +99,6 @@ static void PRINTF(1, 2) lexical_error(const char *fmt, ...);
 
 <*>"/dts-v1/"	{
 			DPRINT("Keyword: /dts-v1/\n");
-			dts_version = 1;
 			BEGIN_DEFAULT();
 			return DT_V1;
 		}

---
base-commit: c369299895a591d96745d6492d4888259b004a9e
change-id: 20260327-dtc-drop-dts_version-153e81c6641c

Best regards,
--  
Nathan Chancellor <nathan@kernel.org>

On Fri, Mar 27, 2026 at 4:39 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> A recent strengthening of -Wunused-but-set-variable (enabled with -Wall)
> in clang under a new subwarning, -Wunused-but-set-global, points out an
> unused static global variable in dtc-lexer.lex.c (compiled from
> dtc-lexer.l):
>
>   scripts/dtc/dtc-lexer.lex.c:641:12: warning: variable 'dts_version' set but not used [-Wunused-but-set-global]
>     641 | static int dts_version = 1;
>         |            ^
>
> This variable has been unused since commit 658f29a51e98 ("of/flattree:
> Update dtc to current mainline."). Remove it to clear up the warning.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
> This is commit 53373d1 ("dtc: Remove unused dts_version in dtc-lexer.l")
> in upstream dtc. I sent it separately to make it easier to backport to
> stable, along with updating the warning and hash to match the kernel's
> version.
> ---
>  scripts/dtc/dtc-lexer.l | 3 ---
>  1 file changed, 3 deletions(-)

We don't take changes to dtc as we just sync with the upstream copy. I
saw you already submitted this upstream, so I will do a sync to pull
this in.

Rob

On Mon, Mar 30, 2026 at 07:19:16AM -0500, Rob Herring wrote:
> On Fri, Mar 27, 2026 at 4:39 PM Nathan Chancellor <nathan@kernel.org> wrote:
> >
> > A recent strengthening of -Wunused-but-set-variable (enabled with -Wall)
> > in clang under a new subwarning, -Wunused-but-set-global, points out an
> > unused static global variable in dtc-lexer.lex.c (compiled from
> > dtc-lexer.l):
> >
> >   scripts/dtc/dtc-lexer.lex.c:641:12: warning: variable 'dts_version' set but not used [-Wunused-but-set-global]
> >     641 | static int dts_version = 1;
> >         |            ^
> >
> > This variable has been unused since commit 658f29a51e98 ("of/flattree:
> > Update dtc to current mainline."). Remove it to clear up the warning.
> >
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> > ---
> > This is commit 53373d1 ("dtc: Remove unused dts_version in dtc-lexer.l")
> > in upstream dtc. I sent it separately to make it easier to backport to
> > stable, along with updating the warning and hash to match the kernel's
> > version.
> > ---
> >  scripts/dtc/dtc-lexer.l | 3 ---
> >  1 file changed, 3 deletions(-)
> 
> We don't take changes to dtc as we just sync with the upstream copy. I
> saw you already submitted this upstream, so I will do a sync to pull
> this in.

Fair enough. As I mentioned in the fold, I will need this in stable so I
figured having a separate patch would make that easier while not
impacting a future sync (since it is already there). I can just wait to
send this to stable directly until the sync lands in Linus's tree.

Cheers,
Nathan