This patch manually suppresses a warning for an unused variable
(yynerrs) emitted by bison.

This warning has been triggered for the first time by clang 15.

This patch also disables `-Wextra`, which is not usually adopted in
QEMU. However, clang 15 triggers the warning fixed in this patch even in
absence of `-Wextra`.

Signed-off-by: Alessandro Di Federico <ale@rev.ng>
---
 target/hexagon/idef-parser/idef-parser.y | 2 ++
 target/hexagon/meson.build               | 1 -
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/target/hexagon/idef-parser/idef-parser.y b/target/hexagon/idef-parser/idef-parser.y
index 8be44a0ad17..de61f48a628 100644
--- a/target/hexagon/idef-parser/idef-parser.y
+++ b/target/hexagon/idef-parser/idef-parser.y
@@ -99,6 +99,8 @@
 /* Input file containing the description of each hexagon instruction */
 input : instructions
       {
+          // Suppress warning about unused yynerrs
+          (void) yynerrs;
           YYACCEPT;
       }
       ;
diff --git a/target/hexagon/meson.build b/target/hexagon/meson.build
index e8f250fcac5..c9d31d095ca 100644
--- a/target/hexagon/meson.build
+++ b/target/hexagon/meson.build
@@ -197,7 +197,6 @@ if idef_parser_enabled and 'hexagon-linux-user' in target_dirs
          idef_parser_dir / 'parser-helpers.c'],
         include_directories: ['idef-parser', '../../include/'],
         dependencies: [glib_dep],
-        c_args: ['-Wextra'],
         native: true
     )
 
-- 
2.38.1

> -----Original Message-----
> From: Alessandro Di Federico <ale@rev.ng>
> Sent: Wednesday, December 21, 2022 4:03 AM
> To: qemu-devel@nongnu.org
> Cc: Philippe Mathieu-Daudé <philmd@linaro.org>; Taylor Simpson
> <tsimpson@quicinc.com>; Anton Johansson <anjo@rev.ng>; Alessandro Di
> Federico <ale@rev.ng>
> Subject: [PATCH] target/hexagon: suppress unused variable warning
> 
> This patch manually suppresses a warning for an unused variable
> (yynerrs) emitted by bison.
> 
> This warning has been triggered for the first time by clang 15.
> 
> This patch also disables `-Wextra`, which is not usually adopted in QEMU.
> However, clang 15 triggers the warning fixed in this patch even in absence of
> `-Wextra`.
> 
> Signed-off-by: Alessandro Di Federico <ale@rev.ng>
> ---
>  target/hexagon/idef-parser/idef-parser.y | 2 ++
>  target/hexagon/meson.build               | 1 -
>  2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/target/hexagon/idef-parser/idef-parser.y b/target/hexagon/idef-
> parser/idef-parser.y
> index 8be44a0ad17..de61f48a628 100644
> --- a/target/hexagon/idef-parser/idef-parser.y
> +++ b/target/hexagon/idef-parser/idef-parser.y
> @@ -99,6 +99,8 @@
>  /* Input file containing the description of each hexagon instruction */  input :
> instructions
>        {
> +          // Suppress warning about unused yynerrs
> +          (void) yynerrs;
>            YYACCEPT;
>        }
>        ;

According to this page
https://qemu-project.gitlab.io/qemu/devel/style.html#comment-style
we should avoid // comments, and the checkpatch script will warn about this.  However, checkpatch does not warn on this patch.

Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Tested-by: Taylor Simpson <tsimpson@quicinc.com>

On 12/21/22 07:43, Taylor Simpson wrote:
>> --- a/target/hexagon/idef-parser/idef-parser.y
>> +++ b/target/hexagon/idef-parser/idef-parser.y
>> @@ -99,6 +99,8 @@
>>   /* Input file containing the description of each hexagon instruction */  input :
>> instructions
>>         {
>> +          // Suppress warning about unused yynerrs
>> +          (void) yynerrs;
>>             YYACCEPT;
>>         }
>>         ;
> 
> According to this page
> https://qemu-project.gitlab.io/qemu/devel/style.html#comment-style
> we should avoid // comments, and the checkpatch script will warn about this.  However, checkpatch does not warn on this patch.

It does not process *.y.


r~

On 21/12/22 11:02, Alessandro Di Federico wrote:
> This patch manually suppresses a warning for an unused variable
> (yynerrs) emitted by bison.
> 
> This warning has been triggered for the first time by clang 15.
> 
> This patch also disables `-Wextra`, which is not usually adopted in
> QEMU. However, clang 15 triggers the warning fixed in this patch even in
> absence of `-Wextra`.
> 
> Signed-off-by: Alessandro Di Federico <ale@rev.ng>
> ---
>   target/hexagon/idef-parser/idef-parser.y | 2 ++
>   target/hexagon/meson.build               | 1 -
>   2 files changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Thanks!