On Fri, 19 Feb 2021, Denis Efremov wrote:
> Check for opencoded swap() implementation.
>
> Signed-off-by: Denis Efremov <efre...@linux.com>
> ---
> Changes in v2:
> - additional patch rule to drop excessive {}
> - fix indentation in patch mode by anchoring ;
>
> scripts/coccinelle/misc/swap.cocci | 101 +++++++++++++++++++++++++++++
> 1 file changed, 101 insertions(+)
> create mode 100644 scripts/coccinelle/misc/swap.cocci
>
> diff --git a/scripts/coccinelle/misc/swap.cocci
> b/scripts/coccinelle/misc/swap.cocci
> new file mode 100644
> index 000000000000..d5da9888c222
> --- /dev/null
> +++ b/scripts/coccinelle/misc/swap.cocci
> @@ -0,0 +1,101 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +///
> +/// Check for opencoded swap() implementation.
> +///
> +// Confidence: High
> +// Copyright: (C) 2021 Denis Efremov ISPRAS
> +// Options: --no-includes --include-headers
> +//
> +// Keywords: swap
> +//
> +
> +virtual patch
> +virtual org
> +virtual report
> +virtual context
> +
> +@r depends on !patch@
> +identifier tmp;
> +expression a, b;
> +type T;
> +position p;
> +@@
> +
> +(
> +* T tmp;
> +|
> +* T tmp = 0;
> +|
> +* T *tmp = NULL;
> +)
> +... when != tmp
> +* tmp = a;
> +* a = b;@p
> +* b = tmp;
> +... when != tmp
> +
> +@rpvar depends on patch@
> +identifier tmp;
> +expression a, b;
> +type T;
> +@@
> +
> +(
> +- T tmp;
> +|
> +- T tmp = 0;
> +|
> +- T *tmp = NULL;
> +)
> +... when != tmp
> +- tmp = a;
> +- a = b;
> +- b = tmp
> ++ swap(a, b)
> + ;
> +... when != tmp
> +
> +
> +@rp depends on patch@
> +identifier tmp;
> +expression a, b;
> +@@
> +
> +- tmp = a;
> +- a = b;
> +- b = tmp
> ++ swap(a, b)
> + ;
A rule like the above should also appear in the non-patch case.
> +
> +@depends on (rpvar || rp)@
This needs to be depends on patch && (rpvar || rp). It doesn't make much
sense, because rpvar and rp both depend on patch, but at the moment that
information isn't propagate everywhere that it is needed.
thanks,
julia
> +@@
> +
> +(
> + for (...;...;...)
> +- {
> + swap(...);
> +- }
> +|
> + while (...)
> +- {
> + swap(...);
> +- }
> +|
> + if (...)
> +- {
> + swap(...);
> +- }
> +)
> +
> +
> +@script:python depends on report@
> +p << r.p;
> +@@
> +
> +coccilib.report.print_report(p[0], "WARNING opportunity for swap()")
> +
> +@script:python depends on org@
> +p << r.p;
> +@@
> +
> +coccilib.org.print_todo(p[0], "WARNING opportunity for swap()")
> --
> 2.26.2
>
>
