[libvirt] [PATCH v3 02/35] cfg.mk: variable initialization when declared with cleanup macro

[Erik Skultety]

On Sat, Jun 30, 2018 at 02:30:06PM +0530, Sukrit Bhatnagar wrote:
> A variable, which is never assigned a value in the function, might get
> passed into the cleanup function which may or may not raise any errors.
>
> To maintain the correct usage, the variable must be initialized, either
> with a value or with NULL. This syntax-check rule takes care of that.
>
> Signed-off-by: Sukrit Bhatnagar <skrtbhtngr at gmail.com>
> ---
>  cfg.mk | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/cfg.mk b/cfg.mk
> index 6bebd0a..196d1b2 100644
> --- a/cfg.mk
> +++ b/cfg.mk
> @@ -1057,6 +1057,17 @@ sc_prohibit_backslash_alignment:
>  	halt='Do not attempt to right-align backslashes' \
>  	  $(_sc_search_regexp)
>
> +# Some syntax rules pertaining to the usage of cleanup macros
> +# implementing GNU C's cleanup attribute
> +
> +# Rule to ensure that varibales declared using a cleanup macro are
> +# always initialized.
> +sc_require_attribute_cleanup_initialization:
> +	@prohibit='VIR_AUTO(FREE|PTR)\(.+\) [^=]+;' \

the following will be caught by spacing check:
VIR_AUTOFREE (type) var;

this will not be caught by any of the macros:
VIR_AUTOFREE(type)var; OR VIR_AUTOFREE(type)<tab>var;

So with a slight modification you'll get:
VIR_AUTO(FREE|PTR)\(.+\) *[^=]+;

The example with the <tab> above makes me wonder why do we have a syntax check
that forbids tabs for indent, but not for a separator, we don't or at least
should not use tabs in any \.[ch] sources.

With the modification above:
Reviewed-by: Erik Skultety <eskultet at redhat.com>