[PATCH] coccinelle: misc: add minmax script

[Denis Efremov]

Check for opencoded min(), max() implementations.

Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
---
 scripts/coccinelle/misc/minmax.cocci | 198 +++++++++++++++++++++++++++
 1 file changed, 198 insertions(+)
 create mode 100644 scripts/coccinelle/misc/minmax.cocci

diff --git a/scripts/coccinelle/misc/minmax.cocci b/scripts/coccinelle/misc/minmax.cocci
new file mode 100644
index 000000000000..9ae689bb14fb
--- /dev/null
+++ b/scripts/coccinelle/misc/minmax.cocci
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0-only
+///
+/// Check for opencoded min(), max() implementations.
+/// Generated patches sometimes require adding a cast to fix compile warning.
+/// Warnings/patches scope intentionally limited to a function body.
+///
+// Confidence: Medium
+// Copyright: (C) 2021 Denis Efremov ISPRAS
+// Options: --no-includes --include-headers
+//
+// Keywords: min, max
+//
+
+
+virtual report
+virtual org
+virtual context
+virtual patch
+
+@rmax depends on !patch@
+identifier func;
+expression x, y;
+binary operator cmp = {>, >=};
+position p;
+@@
+
+func(...)
+{
+	... when any
+*	(x cmp y) ?@p x : y
+	... when any
+}
+
+@rmaxif depends on !patch@
+identifier func;
+expression x, y;
+expression max_val;
+binary operator cmp = {>, >=};
+position p;
+@@
+
+func(...)
+{
+	... when any
+*	if (x cmp@p y) {
+*		max_val = x;
+*	} else {
+*		max_val = y;
+*	}
+	... when any
+}
+
+@rmin depends on !patch@
+identifier func;
+expression x, y;
+binary operator cmp = {<, <=};
+position p;
+@@
+
+func(...)
+{
+	... when any
+*	(x cmp y) ?@p x : y
+	... when any
+}
+
+@rminif depends on !patch@
+identifier func;
+expression x, y;
+expression min_val;
+binary operator cmp = {<, <=};
+position p;
+@@
+
+func(...)
+{
+	... when any
+*	if (x cmp@p y) {
+*		min_val = x;
+*	} else {
+*		min_val = y;
+*	}
+	... when any
+}
+
+@depends on patch@
+identifier func;
+expression x, y;
+binary operator cmp = {>=, >};
+@@
+
+func(...)
+{
+	... when any
+-	(x cmp y) ? x : y
++	max(x, y)
+	... when any
+}
+
+@depends on patch@
+identifier func;
+expression x, y;
+expression max_val;
+binary operator cmp = {>=, >};
+@@
+
+func(...)
+{
+	... when any
+-	if (x cmp y) {
+-		max_val = x;
+-	} else {
+-		max_val = y;
+-	}
++	max_val = max(x, y);
+	... when any
+}
+
+@depends on patch@
+identifier func;
+expression x, y;
+binary operator cmp = {<=, <};
+@@
+
+func(...)
+{
+	... when any
+-	(x cmp y) ? x : y
++	min(x, y)
+	... when any
+}
+
+@depends on patch@
+identifier func;
+expression x, y;
+expression min_val;
+binary operator cmp = {<=, <};
+@@
+
+func(...)
+{
+	... when any
+-	if (x cmp y) {
+-		min_val = x;
+-	} else {
+-		min_val = y;
+-	}
++	min_val = min(x, y);
+	... when any
+}
+
+@script:python depends on report@
+p << rmax.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING opportunity for max()")
+
+@script:python depends on org@
+p << rmax.p;
+@@
+
+coccilib.report.print_todo(p[0], "WARNING opportunity for max()")
+
+@script:python depends on report@
+p << rmaxif.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING opportunity for max()")
+
+@script:python depends on org@
+p << rmaxif.p;
+@@
+
+coccilib.report.print_todo(p[0], "WARNING opportunity for max()")
+
+@script:python depends on report@
+p << rmin.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING opportunity for min()")
+
+@script:python depends on org@
+p << rmin.p;
+@@
+
+coccilib.report.print_todo(p[0], "WARNING opportunity for min()")
+
+@script:python depends on report@
+p << rminif.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING opportunity for min()")
+
+@script:python depends on org@
+p << rminif.p;
+@@
+
+coccilib.report.print_todo(p[0], "WARNING opportunity for min()")
-- 
2.26.2