Re: [PATCH 1/2] Add QEMU_WARN_UNUSED_RESULT attribute

[Daniel P . Berrangé]

On Fri, Nov 10, 2023 at 11:16:38AM +0200, Manos Pitsidianakis wrote:
> This commit adds QEMU_WARN_UNUSED_RESULT, a macro for the gcc function
> attribute `warn_unused_result`. The utility of this attribute is to
> ensure functions that return values that need to be inspected are not
> ignored by the caller.
> 
> Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> ---
>  include/qemu/compiler.h | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
> index c797f0d457..7ddbf1f1cf 100644
> --- a/include/qemu/compiler.h
> +++ b/include/qemu/compiler.h
> @@ -212,6 +212,20 @@
>  # define QEMU_USED
>  #endif
>  
> +/*
> + * From GCC documentation:
> + *
> + *   The warn_unused_result attribute causes a warning to be emitted if a
> + *   caller of the function with this attribute does not use its return 
> value.
> + *   This is useful for functions where not checking the result is either a
> + *   security problem or always a bug, such as realloc.
> + */
> +#if __has_attribute(warn_unused_result)
> +# define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
> +#else
> +# define QEMU_WARN_UNUSED_RESULT
> +#endif

GLib already provides us G_GNUC_WARN_UNUSED_RESULT so don't add this.

With regards,
Daniel
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