[PATCH] coccinelle: misc: add swap script

[Denis Efremov]

Check for opencoded swap() implementation.

Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
---
 scripts/coccinelle/misc/swap.cocci | 77 ++++++++++++++++++++++++++++++
 1 file changed, 77 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..38227a5d0855
--- /dev/null
+++ b/scripts/coccinelle/misc/swap.cocci
@@ -0,0 +1,77 @@
+// 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
+
+@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
+
+@depends on patch@
+identifier tmp;
+expression a, b;
+@@
+
+- tmp = a;
+- a = b;
+- b = tmp;
++ swap(a, b);
+
+@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