Re: [PATCH-for-9.0? v2 4/4] meson: Enable -Wstatic-in-inline

[Paolo Bonzini <pbonzini@redhat.com>]

On 3/26/24 18:10, Philippe Mathieu-Daudé wrote:
> Compilers are clever enough to inline code when necessary.
> 
> The only case we accept an inline function is static in
> header (we use C, not C++).
> 
> Add the -Wstatic-in-inline CPPFLAG to prevent public and
> inline function to be added in the code base.

No problem with the first three patches, but -Wstatic-in-inline is not
warning for non-static inline functions.  The warning is enabled by
default by GCC (which has no way to disable it even) and by clang
outside headers:

f.h:
static int y;

inline int f()
{
     return y;
}

f.c:
#include "f.h"

int main()
{
}

$ clang f.c
./f.h:5:12: warning: static variable 'y' is used in an inline function with external linkage [-Wstatic-in-inline]

$ gcc f.c
f.h:5:12: warning: ‘y’ is static but used in inline function ‘f’ which is not static

The actual effect of this patch is to enable the warning on clang *even
outside headers* (clang only enables the warning in headers by default
because, if a static variable belongs to the main source file, it has a
single definition anyway unlike if it's defined in an included file).

For now I'm queuing patches 1-3 only.

Paolo

> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Message-Id: <20240313184954.42513-5-philmd@linaro.org>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> ---
>   meson.build | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/meson.build b/meson.build
> index c9c3217ba4..f400f7d36c 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -591,6 +591,7 @@ warn_flags = [
>     '-Wold-style-definition',
>     '-Wredundant-decls',
>     '-Wshadow=local',
> +  '-Wstatic-in-inline',
>     '-Wstrict-prototypes',
>     '-Wtype-limits',
>     '-Wundef',