Re: [PATCH v2 for-4.5 1/2] libxl: un-constify return value of libxl_basename

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 01/12/14 11:31, Wei Liu wrote:
> The string returned is malloc'ed but marked as "const".
>
> Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> Cc: Ian Campbell <ian.campbell@citrix.com>
> Cc: Ian Jackson <ian.jackson@eu.citrix.com>
> ---
>  tools/libxl/libxl.h       |   10 ++++++++++
>  tools/libxl/libxl_utils.c |    5 ++++-
>  tools/libxl/libxl_utils.h |    6 +++++-
>  3 files changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
> index 41d6e8d..291c190 100644
> --- a/tools/libxl/libxl.h
> +++ b/tools/libxl/libxl.h
> @@ -478,6 +478,16 @@ typedef struct libxl__ctx libxl_ctx;
>  #endif
>  
>  /*
> + * LIBXL_HAVE_CONST_LIBXL_BASENAME_RETURN_VALUE
> + *
> + * The return value of libxl_basename is malloc'ed but the erroneously
> + * marked as "const" in releases before 4.5.
> + */
> +#if defined(LIBXL_API_VERSION) && LIBXL_API_VERSION < 0x040500
> +#define LIBXL_HAVE_CONST_LIBXL_BASENAME_RETURN_VALUE 1
> +#endif

This define is currently useless.  Only newer code is capable of making
use of newly introduced LIBXL_HAVE_$FOO flags, and with its current
arrangement, this flag is only exposed to code requesting an older API
version.

This instead needs to be LIBXL_HAVE_NONCONST_LIBXL_BASENAME_RETURN_VALUE
which should be 1 for any API version >= 4.5

~Andrew