[PATCH] pif: Add message to static_assert for C11 compliance, fix build with gcc 8

[PATCH] pif: Add message to static_assert for C11 compliance, fix build with gcc 8

[Stefano Brivio]

Seen with gcc 8.5:

---
In file included from passt.h:18,
                 from qrap.c:36:
pif.h: In function 'pif_type':
pif.h:48:44: error: expected ',' before ')' token
  static_assert(sizeof("?") <= PIF_NAME_SIZE);
                                            ^
make: *** [Makefile:105: qrap] Error 1
---

As noted in ba84a3b17af8 ("treewide: Add messages to static_assert()
calls"), static_assert() calls need a message to comply with C11. The
form without message is supported starting from C23 only.

Fixes: cbcd4284111f ("pif: Limit pif names to 128 bytes")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 pif.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pif.h b/pif.h
index 3a1e2e5..dedcaa5 100644
--- a/pif.h
+++ b/pif.h
@@ -45,7 +45,7 @@ static inline const char *pif_type(enum pif_type pt)
 		return pif_type_str[pt];
 	else
 		return "?";
-	static_assert(sizeof("?") <= PIF_NAME_SIZE);
+	static_assert(sizeof("?") <= PIF_NAME_SIZE, "PIF_NAME_SIZE too small");
 }
 
 static inline const char *pif_name(uint8_t pif)
-- 
2.43.0

Re: [PATCH] pif: Add message to static_assert for C11 compliance, fix build with gcc 8

[David Gibson]

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On Sat, Jul 18, 2026 at 09:41:34AM +0200, Stefano Brivio wrote:
> Seen with gcc 8.5:
> 
> ---
> In file included from passt.h:18,
>                  from qrap.c:36:
> pif.h: In function 'pif_type':
> pif.h:48:44: error: expected ',' before ')' token
>   static_assert(sizeof("?") <= PIF_NAME_SIZE);
>                                             ^
> make: *** [Makefile:105: qrap] Error 1
> ---
> 
> As noted in ba84a3b17af8 ("treewide: Add messages to static_assert()
> calls"), static_assert() calls need a message to comply with C11. The
> form without message is supported starting from C23 only.
> 
> Fixes: cbcd4284111f ("pif: Limit pif names to 128 bytes")
> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Huh.  Weird I didn't get a warning for this one, I've caught this same
mistake a bunch of times before because of a warning, though I forget
if it came from the compiler or one of the static checkers.

In any case,

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  pif.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/pif.h b/pif.h
> index 3a1e2e5..dedcaa5 100644
> --- a/pif.h
> +++ b/pif.h
> @@ -45,7 +45,7 @@ static inline const char *pif_type(enum pif_type pt)
>  		return pif_type_str[pt];
>  	else
>  		return "?";
> -	static_assert(sizeof("?") <= PIF_NAME_SIZE);
> +	static_assert(sizeof("?") <= PIF_NAME_SIZE, "PIF_NAME_SIZE too small");
>  }
>  
>  static inline const char *pif_name(uint8_t pif)
> -- 
> 2.43.0
> 

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

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Re: [PATCH] pif: Add message to static_assert for C11 compliance, fix build with gcc 8

[Stefano Brivio]

On Sun, 19 Jul 2026 14:05:27 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> On Sat, Jul 18, 2026 at 09:41:34AM +0200, Stefano Brivio wrote:
> > Seen with gcc 8.5:
> > 
> > ---
> > In file included from passt.h:18,
> >                  from qrap.c:36:
> > pif.h: In function 'pif_type':
> > pif.h:48:44: error: expected ',' before ')' token
> >   static_assert(sizeof("?") <= PIF_NAME_SIZE);
> >                                             ^
> > make: *** [Makefile:105: qrap] Error 1
> > ---
> > 
> > As noted in ba84a3b17af8 ("treewide: Add messages to static_assert()
> > calls"), static_assert() calls need a message to comply with C11. The
> > form without message is supported starting from C23 only.
> > 
> > Fixes: cbcd4284111f ("pif: Limit pif names to 128 bytes")
> > Signed-off-by: Stefano Brivio <sbrivio@redhat.com>  
> 
> Huh.  Weird I didn't get a warning for this one, I've caught this same
> mistake a bunch of times before because of a warning, though I forget
> if it came from the compiler or one of the static checkers.

Same here, I didn't get a warning either, but in ba84a3b17af8 you
mentioned clang-tidy reporting warnings only in some cases, so I guess
that's the kind of warning you would have expected.

-- 
Stefano