Re: [Qemu-devel] [PATCH v4 1/5] qemu/compiler: Define QEMU_NONSTRING

[Thomas Huth <thuth@redhat.com>]

On 2018-12-28 18:33, Philippe Mathieu-Daudé wrote:
> GCC 8 introduced the -Wstringop-truncation checker to detect truncation by
> the strncat and strncpy functions (closely related to -Wstringop-overflow,
> which detect buffer overflow by string-modifying functions declared in
> <string.h>).
> 
> In tandem of -Wstringop-truncation, the "nonstring" attribute was added:
> 
>   The nonstring variable attribute specifies that an object or member
>   declaration with type array of char, signed char, or unsigned char,
>   or pointer to such a type is intended to store character arrays that
>   do not necessarily contain a terminating NUL. This is useful in detecting
>   uses of such arrays or pointers with functions that expect NUL-terminated
>   strings, and to avoid warnings when such an array or pointer is used as
>   an argument to a bounded string manipulation function such as strncpy.
> 
>   From the GCC manual: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-nonstring-variable-attribute
> 
> Add the QEMU_NONSTRING macro which checks if the compiler supports this
> attribute.
> 
> Suggested-by: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Reviewed-by: Thomas Huth <thuth@redhat.com>