[PATCH] Hexagon (target/hexagon) Fix shadow variable when idef-parser is off

[PATCH] Hexagon (target/hexagon) Fix shadow variable when idef-parser is off

[Taylor Simpson]

Adding -Werror=shadow=compatible-local causes Hexagon not to build
when idef-parser is off.  The "label" variable in CHECK_NOSHUF_PRED
shadows a variable in the surrounding code.

Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
---
 target/hexagon/macros.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/hexagon/macros.h b/target/hexagon/macros.h
index 9a51b5709b..f99390e2a8 100644
--- a/target/hexagon/macros.h
+++ b/target/hexagon/macros.h
@@ -93,13 +93,13 @@
 
 #define CHECK_NOSHUF_PRED(GET_EA, SIZE, PRED) \
     do { \
-        TCGLabel *label = gen_new_label(); \
-        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, label); \
+        TCGLabel *noshuf_label = gen_new_label(); \
+        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, noshuf_label); \
         GET_EA; \
         if (insn->slot == 0 && ctx->pkt->pkt_has_store_s1) { \
             probe_noshuf_load(EA, SIZE, ctx->mem_idx); \
         } \
-        gen_set_label(label); \
+        gen_set_label(noshuf_label); \
         if (insn->slot == 0 && ctx->pkt->pkt_has_store_s1) { \
             process_store(ctx, 1); \
         } \
-- 
2.34.1

RE: [PATCH] Hexagon (target/hexagon) Fix shadow variable when idef-parser is off

[Brian Cain]

> -----Original Message-----
> From: Taylor Simpson <ltaylorsimpson@gmail.com>
> Sent: Thursday, November 30, 2023 12:40 PM
> To: qemu-devel@nongnu.org
> Cc: Brian Cain <bcain@quicinc.com>; Matheus Bernardino (QUIC)
> <quic_mathbern@quicinc.com>; Sid Manning <sidneym@quicinc.com>; Marco
> Liebel (QUIC) <quic_mliebel@quicinc.com>; richard.henderson@linaro.org;
> philmd@linaro.org; ale@rev.ng; anjo@rev.ng; ltaylorsimpson@gmail.com
> Subject: [PATCH] Hexagon (target/hexagon) Fix shadow variable when idef-
> parser is off
> 
> WARNING: This email originated from outside of Qualcomm. Please be wary of
> any links or attachments, and do not enable macros.
> 
> Adding -Werror=shadow=compatible-local causes Hexagon not to build
> when idef-parser is off.  The "label" variable in CHECK_NOSHUF_PRED
> shadows a variable in the surrounding code.
> 
> Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
> ---
>  target/hexagon/macros.h | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/target/hexagon/macros.h b/target/hexagon/macros.h
> index 9a51b5709b..f99390e2a8 100644
> --- a/target/hexagon/macros.h
> +++ b/target/hexagon/macros.h
> @@ -93,13 +93,13 @@
> 
>  #define CHECK_NOSHUF_PRED(GET_EA, SIZE, PRED) \
>      do { \
> -        TCGLabel *label = gen_new_label(); \
> -        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, label); \
> +        TCGLabel *noshuf_label = gen_new_label(); \
> +        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, noshuf_label); \
>          GET_EA; \
>          if (insn->slot == 0 && ctx->pkt->pkt_has_store_s1) { \
>              probe_noshuf_load(EA, SIZE, ctx->mem_idx); \
>          } \
> -        gen_set_label(label); \
> +        gen_set_label(noshuf_label); \
>          if (insn->slot == 0 && ctx->pkt->pkt_has_store_s1) { \
>              process_store(ctx, 1); \
>          } \
> --
> 2.34.1

Reviewed-by: Brian Cain <bcain@quicinc.com>

Re: [PATCH] Hexagon (target/hexagon) Fix shadow variable when idef-parser is off

[Philippe Mathieu-Daudé]

On 30/11/23 19:39, Taylor Simpson wrote:
> Adding -Werror=shadow=compatible-local causes Hexagon not to build
> when idef-parser is off.  The "label" variable in CHECK_NOSHUF_PRED
> shadows a variable in the surrounding code.
> 
> Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
> ---
>   target/hexagon/macros.h | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/target/hexagon/macros.h b/target/hexagon/macros.h
> index 9a51b5709b..f99390e2a8 100644
> --- a/target/hexagon/macros.h
> +++ b/target/hexagon/macros.h
> @@ -93,13 +93,13 @@
>   
>   #define CHECK_NOSHUF_PRED(GET_EA, SIZE, PRED) \
>       do { \
> -        TCGLabel *label = gen_new_label(); \
> -        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, label); \
> +        TCGLabel *noshuf_label = gen_new_label(); \
> +        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, noshuf_label); \

Fragile, but sufficient.

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

RE: [PATCH] Hexagon (target/hexagon) Fix shadow variable when idef-parser is off

[Brian Cain]

> -----Original Message-----
> From: Philippe Mathieu-Daudé <philmd@linaro.org>
> Sent: Thursday, November 30, 2023 2:17 PM
> To: Taylor Simpson <ltaylorsimpson@gmail.com>; qemu-devel@nongnu.org
> Cc: Brian Cain <bcain@quicinc.com>; Matheus Bernardino (QUIC)
> <quic_mathbern@quicinc.com>; Sid Manning <sidneym@quicinc.com>; Marco
> Liebel (QUIC) <quic_mliebel@quicinc.com>; richard.henderson@linaro.org;
> ale@rev.ng; anjo@rev.ng
> Subject: Re: [PATCH] Hexagon (target/hexagon) Fix shadow variable when idef-
> parser is off
> 
> WARNING: This email originated from outside of Qualcomm. Please be wary of
> any links or attachments, and do not enable macros.
> 
> On 30/11/23 19:39, Taylor Simpson wrote:
> > Adding -Werror=shadow=compatible-local causes Hexagon not to build
> > when idef-parser is off.  The "label" variable in CHECK_NOSHUF_PRED
> > shadows a variable in the surrounding code.
> >
> > Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
> > ---
> >   target/hexagon/macros.h | 6 +++---
> >   1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/target/hexagon/macros.h b/target/hexagon/macros.h
> > index 9a51b5709b..f99390e2a8 100644
> > --- a/target/hexagon/macros.h
> > +++ b/target/hexagon/macros.h
> > @@ -93,13 +93,13 @@
> >
> >   #define CHECK_NOSHUF_PRED(GET_EA, SIZE, PRED) \
> >       do { \
> > -        TCGLabel *label = gen_new_label(); \
> > -        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, label); \
> > +        TCGLabel *noshuf_label = gen_new_label(); \
> > +        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, noshuf_label); \
> 
> Fragile, but sufficient.

The fragility here refers to the fact that CHECK_NOSHUF_PRED() macro could show up in other contexts and then could shadow those?

We could change the macro to a function or expand the macro to take a label declared outside.  Would that be preferred?  Or are there other suggestions?

-Brian

Re: [PATCH] Hexagon (target/hexagon) Fix shadow variable when idef-parser is off

[Philippe Mathieu-Daudé]

On 30/11/23 21:39, Brian Cain wrote:
> 
> 
>> -----Original Message-----
>> From: Philippe Mathieu-Daudé <philmd@linaro.org>
>> Sent: Thursday, November 30, 2023 2:17 PM
>> To: Taylor Simpson <ltaylorsimpson@gmail.com>; qemu-devel@nongnu.org
>> Cc: Brian Cain <bcain@quicinc.com>; Matheus Bernardino (QUIC)
>> <quic_mathbern@quicinc.com>; Sid Manning <sidneym@quicinc.com>; Marco
>> Liebel (QUIC) <quic_mliebel@quicinc.com>; richard.henderson@linaro.org;
>> ale@rev.ng; anjo@rev.ng
>> Subject: Re: [PATCH] Hexagon (target/hexagon) Fix shadow variable when idef-
>> parser is off
>>
>> WARNING: This email originated from outside of Qualcomm. Please be wary of
>> any links or attachments, and do not enable macros.
>>
>> On 30/11/23 19:39, Taylor Simpson wrote:
>>> Adding -Werror=shadow=compatible-local causes Hexagon not to build
>>> when idef-parser is off.  The "label" variable in CHECK_NOSHUF_PRED
>>> shadows a variable in the surrounding code.
>>>
>>> Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
>>> ---
>>>    target/hexagon/macros.h | 6 +++---
>>>    1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/target/hexagon/macros.h b/target/hexagon/macros.h
>>> index 9a51b5709b..f99390e2a8 100644
>>> --- a/target/hexagon/macros.h
>>> +++ b/target/hexagon/macros.h
>>> @@ -93,13 +93,13 @@
>>>
>>>    #define CHECK_NOSHUF_PRED(GET_EA, SIZE, PRED) \
>>>        do { \
>>> -        TCGLabel *label = gen_new_label(); \
>>> -        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, label); \
>>> +        TCGLabel *noshuf_label = gen_new_label(); \
>>> +        tcg_gen_brcondi_tl(TCG_COND_EQ, PRED, 0, noshuf_label); \
>>
>> Fragile, but sufficient.
> 
> The fragility here refers to the fact that CHECK_NOSHUF_PRED() macro could show up in other contexts and then could shadow those?

Yes.

> We could change the macro to a function or expand the macro to take a label declared outside.  Would that be preferred?  Or are there other suggestions?

Nah, this is good enough, no need to over-engineer IMHO
(I just wanted to remark this could still bit us in the
future, and -Werror will fire).

Regards,

Phil.